1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the SelectionDAG::Legalize method.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/APFloat.h"
14 #include "llvm/ADT/APInt.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/SetVector.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/SmallSet.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/Analysis/TargetLibraryInfo.h"
21 #include "llvm/CodeGen/ISDOpcodes.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/RuntimeLibcalls.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGNodes.h"
28 #include "llvm/CodeGen/TargetFrameLowering.h"
29 #include "llvm/CodeGen/TargetLowering.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/CodeGen/ValueTypes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/MachineValueType.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include <algorithm>
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
137 
138   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall LC,
139                        SmallVectorImpl<SDValue> &Results);
140   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
141                        RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
142                        RTLIB::Libcall Call_F128,
143                        RTLIB::Libcall Call_PPCF128,
144                        SmallVectorImpl<SDValue> &Results);
145   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
146                            RTLIB::Libcall Call_I8,
147                            RTLIB::Libcall Call_I16,
148                            RTLIB::Libcall Call_I32,
149                            RTLIB::Libcall Call_I64,
150                            RTLIB::Libcall Call_I128);
151   void ExpandArgFPLibCall(SDNode *Node,
152                           RTLIB::Libcall Call_F32, RTLIB::Libcall Call_F64,
153                           RTLIB::Libcall Call_F80, RTLIB::Libcall Call_F128,
154                           RTLIB::Libcall Call_PPCF128,
155                           SmallVectorImpl<SDValue> &Results);
156   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
157   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
158 
159   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
160                            const SDLoc &dl);
161   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
162                            const SDLoc &dl, SDValue ChainIn);
163   SDValue ExpandBUILD_VECTOR(SDNode *Node);
164   SDValue ExpandSPLAT_VECTOR(SDNode *Node);
165   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
166   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
167                                 SmallVectorImpl<SDValue> &Results);
168   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
169                          SDValue Value) const;
170   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
171                           SDValue NewIntValue) const;
172   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
173   SDValue ExpandFABS(SDNode *Node) const;
174   SDValue ExpandFNEG(SDNode *Node) const;
175   SDValue ExpandLegalINT_TO_FP(SDNode *Node, SDValue &Chain);
176   void PromoteLegalINT_TO_FP(SDNode *N, const SDLoc &dl,
177                              SmallVectorImpl<SDValue> &Results);
178   void PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
179                              SmallVectorImpl<SDValue> &Results);
180   SDValue PromoteLegalFP_TO_INT_SAT(SDNode *Node, const SDLoc &dl);
181 
182   SDValue ExpandPARITY(SDValue Op, const SDLoc &dl);
183 
184   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
185   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
186   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
187 
188   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
189   SDValue ExpandConstant(ConstantSDNode *CP);
190 
191   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
192   bool ExpandNode(SDNode *Node);
193   void ConvertNodeToLibcall(SDNode *Node);
194   void PromoteNode(SDNode *Node);
195 
196 public:
197   // Node replacement helpers
198 
199   void ReplacedNode(SDNode *N) {
200     LegalizedNodes.erase(N);
201     if (UpdatedNodes)
202       UpdatedNodes->insert(N);
203   }
204 
205   void ReplaceNode(SDNode *Old, SDNode *New) {
206     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
207                dbgs() << "     with:      "; New->dump(&DAG));
208 
209     assert(Old->getNumValues() == New->getNumValues() &&
210            "Replacing one node with another that produces a different number "
211            "of values!");
212     DAG.ReplaceAllUsesWith(Old, New);
213     if (UpdatedNodes)
214       UpdatedNodes->insert(New);
215     ReplacedNode(Old);
216   }
217 
218   void ReplaceNode(SDValue Old, SDValue New) {
219     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
220                dbgs() << "     with:      "; New->dump(&DAG));
221 
222     DAG.ReplaceAllUsesWith(Old, New);
223     if (UpdatedNodes)
224       UpdatedNodes->insert(New.getNode());
225     ReplacedNode(Old.getNode());
226   }
227 
228   void ReplaceNode(SDNode *Old, const SDValue *New) {
229     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
230 
231     DAG.ReplaceAllUsesWith(Old, New);
232     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
233       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
234                  New[i]->dump(&DAG));
235       if (UpdatedNodes)
236         UpdatedNodes->insert(New[i].getNode());
237     }
238     ReplacedNode(Old);
239   }
240 
241   void ReplaceNodeWithValue(SDValue Old, SDValue New) {
242     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
243                dbgs() << "     with:      "; New->dump(&DAG));
244 
245     DAG.ReplaceAllUsesOfValueWith(Old, New);
246     if (UpdatedNodes)
247       UpdatedNodes->insert(New.getNode());
248     ReplacedNode(Old.getNode());
249   }
250 };
251 
252 } // end anonymous namespace
253 
254 /// Return a vector shuffle operation which
255 /// performs the same shuffle in terms of order or result bytes, but on a type
256 /// whose vector element type is narrower than the original shuffle type.
257 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
258 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
259     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
260     ArrayRef<int> Mask) const {
261   unsigned NumMaskElts = VT.getVectorNumElements();
262   unsigned NumDestElts = NVT.getVectorNumElements();
263   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
264 
265   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
266 
267   if (NumEltsGrowth == 1)
268     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
269 
270   SmallVector<int, 8> NewMask;
271   for (unsigned i = 0; i != NumMaskElts; ++i) {
272     int Idx = Mask[i];
273     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
274       if (Idx < 0)
275         NewMask.push_back(-1);
276       else
277         NewMask.push_back(Idx * NumEltsGrowth + j);
278     }
279   }
280   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
281   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
282   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
283 }
284 
285 /// Expands the ConstantFP node to an integer constant or
286 /// a load from the constant pool.
287 SDValue
288 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
289   bool Extend = false;
290   SDLoc dl(CFP);
291 
292   // If a FP immediate is precise when represented as a float and if the
293   // target can do an extending load from float to double, we put it into
294   // the constant pool as a float, even if it's is statically typed as a
295   // double.  This shrinks FP constants and canonicalizes them for targets where
296   // an FP extending load is the same cost as a normal load (such as on the x87
297   // fp stack or PPC FP unit).
298   EVT VT = CFP->getValueType(0);
299   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
300   if (!UseCP) {
301     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
302     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
303                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
304   }
305 
306   APFloat APF = CFP->getValueAPF();
307   EVT OrigVT = VT;
308   EVT SVT = VT;
309 
310   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
311   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
312   if (!APF.isSignaling()) {
313     while (SVT != MVT::f32 && SVT != MVT::f16) {
314       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
315       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
316           // Only do this if the target has a native EXTLOAD instruction from
317           // smaller type.
318           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
319           TLI.ShouldShrinkFPConstant(OrigVT)) {
320         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
321         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
322         VT = SVT;
323         Extend = true;
324       }
325     }
326   }
327 
328   SDValue CPIdx =
329       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
330   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
331   if (Extend) {
332     SDValue Result = DAG.getExtLoad(
333         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
334         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
335         Alignment);
336     return Result;
337   }
338   SDValue Result = DAG.getLoad(
339       OrigVT, dl, DAG.getEntryNode(), CPIdx,
340       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
341   return Result;
342 }
343 
344 /// Expands the Constant node to a load from the constant pool.
345 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
346   SDLoc dl(CP);
347   EVT VT = CP->getValueType(0);
348   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
349                                       TLI.getPointerTy(DAG.getDataLayout()));
350   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
351   SDValue Result = DAG.getLoad(
352       VT, dl, DAG.getEntryNode(), CPIdx,
353       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
354   return Result;
355 }
356 
357 /// Some target cannot handle a variable insertion index for the
358 /// INSERT_VECTOR_ELT instruction.  In this case, it
359 /// is necessary to spill the vector being inserted into to memory, perform
360 /// the insert there, and then read the result back.
361 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
362                                                              SDValue Val,
363                                                              SDValue Idx,
364                                                              const SDLoc &dl) {
365   SDValue Tmp1 = Vec;
366   SDValue Tmp2 = Val;
367   SDValue Tmp3 = Idx;
368 
369   // If the target doesn't support this, we have to spill the input vector
370   // to a temporary stack slot, update the element, then reload it.  This is
371   // badness.  We could also load the value into a vector register (either
372   // with a "move to register" or "extload into register" instruction, then
373   // permute it into place, if the idx is a constant and if the idx is
374   // supported by the target.
375   EVT VT    = Tmp1.getValueType();
376   EVT EltVT = VT.getVectorElementType();
377   SDValue StackPtr = DAG.CreateStackTemporary(VT);
378 
379   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
380 
381   // Store the vector.
382   SDValue Ch = DAG.getStore(
383       DAG.getEntryNode(), dl, Tmp1, StackPtr,
384       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
385 
386   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
387 
388   // Store the scalar value.
389   Ch = DAG.getTruncStore(
390       Ch, dl, Tmp2, StackPtr2,
391       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()), EltVT);
392   // Load the updated vector.
393   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
394                                                DAG.getMachineFunction(), SPFI));
395 }
396 
397 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
398                                                       SDValue Idx,
399                                                       const SDLoc &dl) {
400   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
401     // SCALAR_TO_VECTOR requires that the type of the value being inserted
402     // match the element type of the vector being created, except for
403     // integers in which case the inserted value can be over width.
404     EVT EltVT = Vec.getValueType().getVectorElementType();
405     if (Val.getValueType() == EltVT ||
406         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
407       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
408                                   Vec.getValueType(), Val);
409 
410       unsigned NumElts = Vec.getValueType().getVectorNumElements();
411       // We generate a shuffle of InVec and ScVec, so the shuffle mask
412       // should be 0,1,2,3,4,5... with the appropriate element replaced with
413       // elt 0 of the RHS.
414       SmallVector<int, 8> ShufOps;
415       for (unsigned i = 0; i != NumElts; ++i)
416         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
417 
418       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
419     }
420   }
421   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
422 }
423 
424 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
425   if (!ISD::isNormalStore(ST))
426     return SDValue();
427 
428   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
429   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
430   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
431   // to phase ordering between legalized code and the dag combiner.  This
432   // probably means that we need to integrate dag combiner and legalizer
433   // together.
434   // We generally can't do this one for long doubles.
435   SDValue Chain = ST->getChain();
436   SDValue Ptr = ST->getBasePtr();
437   SDValue Value = ST->getValue();
438   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
439   AAMDNodes AAInfo = ST->getAAInfo();
440   SDLoc dl(ST);
441 
442   // Don't optimise TargetConstantFP
443   if (Value.getOpcode() == ISD::TargetConstantFP)
444     return SDValue();
445 
446   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
447     if (CFP->getValueType(0) == MVT::f32 &&
448         TLI.isTypeLegal(MVT::i32)) {
449       SDValue Con = DAG.getConstant(CFP->getValueAPF().
450                                       bitcastToAPInt().zextOrTrunc(32),
451                                     SDLoc(CFP), MVT::i32);
452       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
453                           ST->getOriginalAlign(), MMOFlags, AAInfo);
454     }
455 
456     if (CFP->getValueType(0) == MVT::f64) {
457       // If this target supports 64-bit registers, do a single 64-bit store.
458       if (TLI.isTypeLegal(MVT::i64)) {
459         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
460                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
461         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
462                             ST->getOriginalAlign(), MMOFlags, AAInfo);
463       }
464 
465       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
466         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
467         // stores.  If the target supports neither 32- nor 64-bits, this
468         // xform is certainly not worth it.
469         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
470         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
471         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
472         if (DAG.getDataLayout().isBigEndian())
473           std::swap(Lo, Hi);
474 
475         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(),
476                           ST->getOriginalAlign(), MMOFlags, AAInfo);
477         Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(4), dl);
478         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
479                           ST->getPointerInfo().getWithOffset(4),
480                           ST->getOriginalAlign(), MMOFlags, AAInfo);
481 
482         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
483       }
484     }
485   }
486   return SDValue();
487 }
488 
489 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
490   StoreSDNode *ST = cast<StoreSDNode>(Node);
491   SDValue Chain = ST->getChain();
492   SDValue Ptr = ST->getBasePtr();
493   SDLoc dl(Node);
494 
495   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
496   AAMDNodes AAInfo = ST->getAAInfo();
497 
498   if (!ST->isTruncatingStore()) {
499     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
500     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
501       ReplaceNode(ST, OptStore);
502       return;
503     }
504 
505     SDValue Value = ST->getValue();
506     MVT VT = Value.getSimpleValueType();
507     switch (TLI.getOperationAction(ISD::STORE, VT)) {
508     default: llvm_unreachable("This action is not supported yet!");
509     case TargetLowering::Legal: {
510       // If this is an unaligned store and the target doesn't support it,
511       // expand it.
512       EVT MemVT = ST->getMemoryVT();
513       const DataLayout &DL = DAG.getDataLayout();
514       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
515                                               *ST->getMemOperand())) {
516         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
517         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
518         ReplaceNode(SDValue(ST, 0), Result);
519       } else
520         LLVM_DEBUG(dbgs() << "Legal store\n");
521       break;
522     }
523     case TargetLowering::Custom: {
524       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
525       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
526       if (Res && Res != SDValue(Node, 0))
527         ReplaceNode(SDValue(Node, 0), Res);
528       return;
529     }
530     case TargetLowering::Promote: {
531       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
532       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
533              "Can only promote stores to same size type");
534       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
535       SDValue Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
536                                     ST->getOriginalAlign(), MMOFlags, AAInfo);
537       ReplaceNode(SDValue(Node, 0), Result);
538       break;
539     }
540     }
541     return;
542   }
543 
544   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
545   SDValue Value = ST->getValue();
546   EVT StVT = ST->getMemoryVT();
547   TypeSize StWidth = StVT.getSizeInBits();
548   TypeSize StSize = StVT.getStoreSizeInBits();
549   auto &DL = DAG.getDataLayout();
550 
551   if (StWidth != StSize) {
552     // Promote to a byte-sized store with upper bits zero if not
553     // storing an integral number of bytes.  For example, promote
554     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
555     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), StSize.getFixedSize());
556     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
557     SDValue Result =
558         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
559                           ST->getOriginalAlign(), MMOFlags, AAInfo);
560     ReplaceNode(SDValue(Node, 0), Result);
561   } else if (!StVT.isVector() && !isPowerOf2_64(StWidth.getFixedSize())) {
562     // If not storing a power-of-2 number of bits, expand as two stores.
563     assert(!StVT.isVector() && "Unsupported truncstore!");
564     unsigned StWidthBits = StWidth.getFixedSize();
565     unsigned LogStWidth = Log2_32(StWidthBits);
566     assert(LogStWidth < 32);
567     unsigned RoundWidth = 1 << LogStWidth;
568     assert(RoundWidth < StWidthBits);
569     unsigned ExtraWidth = StWidthBits - RoundWidth;
570     assert(ExtraWidth < RoundWidth);
571     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
572            "Store size not an integral number of bytes!");
573     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
574     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
575     SDValue Lo, Hi;
576     unsigned IncrementSize;
577 
578     if (DL.isLittleEndian()) {
579       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
580       // Store the bottom RoundWidth bits.
581       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
582                              RoundVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
583 
584       // Store the remaining ExtraWidth bits.
585       IncrementSize = RoundWidth / 8;
586       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
587       Hi = DAG.getNode(
588           ISD::SRL, dl, Value.getValueType(), Value,
589           DAG.getConstant(RoundWidth, dl,
590                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
591       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
592                              ST->getPointerInfo().getWithOffset(IncrementSize),
593                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
594     } else {
595       // Big endian - avoid unaligned stores.
596       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
597       // Store the top RoundWidth bits.
598       Hi = DAG.getNode(
599           ISD::SRL, dl, Value.getValueType(), Value,
600           DAG.getConstant(ExtraWidth, dl,
601                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
602       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(), RoundVT,
603                              ST->getOriginalAlign(), MMOFlags, AAInfo);
604 
605       // Store the remaining ExtraWidth bits.
606       IncrementSize = RoundWidth / 8;
607       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
608                         DAG.getConstant(IncrementSize, dl,
609                                         Ptr.getValueType()));
610       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
611                              ST->getPointerInfo().getWithOffset(IncrementSize),
612                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
613     }
614 
615     // The order of the stores doesn't matter.
616     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
617     ReplaceNode(SDValue(Node, 0), Result);
618   } else {
619     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
620     default: llvm_unreachable("This action is not supported yet!");
621     case TargetLowering::Legal: {
622       EVT MemVT = ST->getMemoryVT();
623       // If this is an unaligned store and the target doesn't support it,
624       // expand it.
625       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
626                                               *ST->getMemOperand())) {
627         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
628         ReplaceNode(SDValue(ST, 0), Result);
629       }
630       break;
631     }
632     case TargetLowering::Custom: {
633       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
634       if (Res && Res != SDValue(Node, 0))
635         ReplaceNode(SDValue(Node, 0), Res);
636       return;
637     }
638     case TargetLowering::Expand:
639       assert(!StVT.isVector() &&
640              "Vector Stores are handled in LegalizeVectorOps");
641 
642       SDValue Result;
643 
644       // TRUNCSTORE:i16 i32 -> STORE i16
645       if (TLI.isTypeLegal(StVT)) {
646         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
647         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
648                               ST->getOriginalAlign(), MMOFlags, AAInfo);
649       } else {
650         // The in-memory type isn't legal. Truncate to the type it would promote
651         // to, and then do a truncstore.
652         Value = DAG.getNode(ISD::TRUNCATE, dl,
653                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
654                             Value);
655         Result =
656             DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), StVT,
657                               ST->getOriginalAlign(), MMOFlags, AAInfo);
658       }
659 
660       ReplaceNode(SDValue(Node, 0), Result);
661       break;
662     }
663   }
664 }
665 
666 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
667   LoadSDNode *LD = cast<LoadSDNode>(Node);
668   SDValue Chain = LD->getChain();  // The chain.
669   SDValue Ptr = LD->getBasePtr();  // The base pointer.
670   SDValue Value;                   // The value returned by the load op.
671   SDLoc dl(Node);
672 
673   ISD::LoadExtType ExtType = LD->getExtensionType();
674   if (ExtType == ISD::NON_EXTLOAD) {
675     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
676     MVT VT = Node->getSimpleValueType(0);
677     SDValue RVal = SDValue(Node, 0);
678     SDValue RChain = SDValue(Node, 1);
679 
680     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
681     default: llvm_unreachable("This action is not supported yet!");
682     case TargetLowering::Legal: {
683       EVT MemVT = LD->getMemoryVT();
684       const DataLayout &DL = DAG.getDataLayout();
685       // If this is an unaligned load and the target doesn't support it,
686       // expand it.
687       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
688                                               *LD->getMemOperand())) {
689         std::tie(RVal, RChain) = TLI.expandUnalignedLoad(LD, DAG);
690       }
691       break;
692     }
693     case TargetLowering::Custom:
694       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
695         RVal = Res;
696         RChain = Res.getValue(1);
697       }
698       break;
699 
700     case TargetLowering::Promote: {
701       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
702       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
703              "Can only promote loads to same size type");
704 
705       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
706       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
707       RChain = Res.getValue(1);
708       break;
709     }
710     }
711     if (RChain.getNode() != Node) {
712       assert(RVal.getNode() != Node && "Load must be completely replaced");
713       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
714       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
715       if (UpdatedNodes) {
716         UpdatedNodes->insert(RVal.getNode());
717         UpdatedNodes->insert(RChain.getNode());
718       }
719       ReplacedNode(Node);
720     }
721     return;
722   }
723 
724   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
725   EVT SrcVT = LD->getMemoryVT();
726   TypeSize SrcWidth = SrcVT.getSizeInBits();
727   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
728   AAMDNodes AAInfo = LD->getAAInfo();
729 
730   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
731       // Some targets pretend to have an i1 loading operation, and actually
732       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
733       // bits are guaranteed to be zero; it helps the optimizers understand
734       // that these bits are zero.  It is also useful for EXTLOAD, since it
735       // tells the optimizers that those bits are undefined.  It would be
736       // nice to have an effective generic way of getting these benefits...
737       // Until such a way is found, don't insist on promoting i1 here.
738       (SrcVT != MVT::i1 ||
739        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
740          TargetLowering::Promote)) {
741     // Promote to a byte-sized load if not loading an integral number of
742     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
743     unsigned NewWidth = SrcVT.getStoreSizeInBits();
744     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
745     SDValue Ch;
746 
747     // The extra bits are guaranteed to be zero, since we stored them that
748     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
749 
750     ISD::LoadExtType NewExtType =
751       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
752 
753     SDValue Result = DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
754                                     Chain, Ptr, LD->getPointerInfo(), NVT,
755                                     LD->getOriginalAlign(), MMOFlags, AAInfo);
756 
757     Ch = Result.getValue(1); // The chain.
758 
759     if (ExtType == ISD::SEXTLOAD)
760       // Having the top bits zero doesn't help when sign extending.
761       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
762                            Result.getValueType(),
763                            Result, DAG.getValueType(SrcVT));
764     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
765       // All the top bits are guaranteed to be zero - inform the optimizers.
766       Result = DAG.getNode(ISD::AssertZext, dl,
767                            Result.getValueType(), Result,
768                            DAG.getValueType(SrcVT));
769 
770     Value = Result;
771     Chain = Ch;
772   } else if (!isPowerOf2_64(SrcWidth.getKnownMinSize())) {
773     // If not loading a power-of-2 number of bits, expand as two loads.
774     assert(!SrcVT.isVector() && "Unsupported extload!");
775     unsigned SrcWidthBits = SrcWidth.getFixedSize();
776     unsigned LogSrcWidth = Log2_32(SrcWidthBits);
777     assert(LogSrcWidth < 32);
778     unsigned RoundWidth = 1 << LogSrcWidth;
779     assert(RoundWidth < SrcWidthBits);
780     unsigned ExtraWidth = SrcWidthBits - RoundWidth;
781     assert(ExtraWidth < RoundWidth);
782     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
783            "Load size not an integral number of bytes!");
784     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
785     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
786     SDValue Lo, Hi, Ch;
787     unsigned IncrementSize;
788     auto &DL = DAG.getDataLayout();
789 
790     if (DL.isLittleEndian()) {
791       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
792       // Load the bottom RoundWidth bits.
793       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
794                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
795                           MMOFlags, AAInfo);
796 
797       // Load the remaining ExtraWidth bits.
798       IncrementSize = RoundWidth / 8;
799       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
800       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
801                           LD->getPointerInfo().getWithOffset(IncrementSize),
802                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
803 
804       // Build a factor node to remember that this load is independent of
805       // the other one.
806       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
807                        Hi.getValue(1));
808 
809       // Move the top bits to the right place.
810       Hi = DAG.getNode(
811           ISD::SHL, dl, Hi.getValueType(), Hi,
812           DAG.getConstant(RoundWidth, dl,
813                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
814 
815       // Join the hi and lo parts.
816       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
817     } else {
818       // Big endian - avoid unaligned loads.
819       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
820       // Load the top RoundWidth bits.
821       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
822                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
823                           MMOFlags, AAInfo);
824 
825       // Load the remaining ExtraWidth bits.
826       IncrementSize = RoundWidth / 8;
827       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
828       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
829                           LD->getPointerInfo().getWithOffset(IncrementSize),
830                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
831 
832       // Build a factor node to remember that this load is independent of
833       // the other one.
834       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
835                        Hi.getValue(1));
836 
837       // Move the top bits to the right place.
838       Hi = DAG.getNode(
839           ISD::SHL, dl, Hi.getValueType(), Hi,
840           DAG.getConstant(ExtraWidth, dl,
841                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
842 
843       // Join the hi and lo parts.
844       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
845     }
846 
847     Chain = Ch;
848   } else {
849     bool isCustom = false;
850     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
851                                  SrcVT.getSimpleVT())) {
852     default: llvm_unreachable("This action is not supported yet!");
853     case TargetLowering::Custom:
854       isCustom = true;
855       LLVM_FALLTHROUGH;
856     case TargetLowering::Legal:
857       Value = SDValue(Node, 0);
858       Chain = SDValue(Node, 1);
859 
860       if (isCustom) {
861         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
862           Value = Res;
863           Chain = Res.getValue(1);
864         }
865       } else {
866         // If this is an unaligned load and the target doesn't support it,
867         // expand it.
868         EVT MemVT = LD->getMemoryVT();
869         const DataLayout &DL = DAG.getDataLayout();
870         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT,
871                                     *LD->getMemOperand())) {
872           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
873         }
874       }
875       break;
876 
877     case TargetLowering::Expand: {
878       EVT DestVT = Node->getValueType(0);
879       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
880         // If the source type is not legal, see if there is a legal extload to
881         // an intermediate type that we can then extend further.
882         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
883         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
884             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
885           // If we are loading a legal type, this is a non-extload followed by a
886           // full extend.
887           ISD::LoadExtType MidExtType =
888               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
889 
890           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
891                                         SrcVT, LD->getMemOperand());
892           unsigned ExtendOp =
893               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
894           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
895           Chain = Load.getValue(1);
896           break;
897         }
898 
899         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
900         // normal undefined upper bits behavior to allow using an in-reg extend
901         // with the illegal FP type, so load as an integer and do the
902         // from-integer conversion.
903         if (SrcVT.getScalarType() == MVT::f16) {
904           EVT ISrcVT = SrcVT.changeTypeToInteger();
905           EVT IDestVT = DestVT.changeTypeToInteger();
906           EVT ILoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
907 
908           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, ILoadVT, Chain,
909                                           Ptr, ISrcVT, LD->getMemOperand());
910           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
911           Chain = Result.getValue(1);
912           break;
913         }
914       }
915 
916       assert(!SrcVT.isVector() &&
917              "Vector Loads are handled in LegalizeVectorOps");
918 
919       // FIXME: This does not work for vectors on most targets.  Sign-
920       // and zero-extend operations are currently folded into extending
921       // loads, whether they are legal or not, and then we end up here
922       // without any support for legalizing them.
923       assert(ExtType != ISD::EXTLOAD &&
924              "EXTLOAD should always be supported!");
925       // Turn the unsupported load into an EXTLOAD followed by an
926       // explicit zero/sign extend inreg.
927       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
928                                       Node->getValueType(0),
929                                       Chain, Ptr, SrcVT,
930                                       LD->getMemOperand());
931       SDValue ValRes;
932       if (ExtType == ISD::SEXTLOAD)
933         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
934                              Result.getValueType(),
935                              Result, DAG.getValueType(SrcVT));
936       else
937         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT);
938       Value = ValRes;
939       Chain = Result.getValue(1);
940       break;
941     }
942     }
943   }
944 
945   // Since loads produce two values, make sure to remember that we legalized
946   // both of them.
947   if (Chain.getNode() != Node) {
948     assert(Value.getNode() != Node && "Load must be completely replaced");
949     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
950     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
951     if (UpdatedNodes) {
952       UpdatedNodes->insert(Value.getNode());
953       UpdatedNodes->insert(Chain.getNode());
954     }
955     ReplacedNode(Node);
956   }
957 }
958 
959 /// Return a legal replacement for the given operation, with all legal operands.
960 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
961   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
962 
963   // Allow illegal target nodes and illegal registers.
964   if (Node->getOpcode() == ISD::TargetConstant ||
965       Node->getOpcode() == ISD::Register)
966     return;
967 
968 #ifndef NDEBUG
969   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
970     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
971              TargetLowering::TypeLegal &&
972            "Unexpected illegal type!");
973 
974   for (const SDValue &Op : Node->op_values())
975     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
976               TargetLowering::TypeLegal ||
977             Op.getOpcode() == ISD::TargetConstant ||
978             Op.getOpcode() == ISD::Register) &&
979             "Unexpected illegal type!");
980 #endif
981 
982   // Figure out the correct action; the way to query this varies by opcode
983   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
984   bool SimpleFinishLegalizing = true;
985   switch (Node->getOpcode()) {
986   case ISD::INTRINSIC_W_CHAIN:
987   case ISD::INTRINSIC_WO_CHAIN:
988   case ISD::INTRINSIC_VOID:
989   case ISD::STACKSAVE:
990     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
991     break;
992   case ISD::GET_DYNAMIC_AREA_OFFSET:
993     Action = TLI.getOperationAction(Node->getOpcode(),
994                                     Node->getValueType(0));
995     break;
996   case ISD::VAARG:
997     Action = TLI.getOperationAction(Node->getOpcode(),
998                                     Node->getValueType(0));
999     if (Action != TargetLowering::Promote)
1000       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
1001     break;
1002   case ISD::FP_TO_FP16:
1003   case ISD::SINT_TO_FP:
1004   case ISD::UINT_TO_FP:
1005   case ISD::EXTRACT_VECTOR_ELT:
1006   case ISD::LROUND:
1007   case ISD::LLROUND:
1008   case ISD::LRINT:
1009   case ISD::LLRINT:
1010     Action = TLI.getOperationAction(Node->getOpcode(),
1011                                     Node->getOperand(0).getValueType());
1012     break;
1013   case ISD::STRICT_FP_TO_FP16:
1014   case ISD::STRICT_SINT_TO_FP:
1015   case ISD::STRICT_UINT_TO_FP:
1016   case ISD::STRICT_LRINT:
1017   case ISD::STRICT_LLRINT:
1018   case ISD::STRICT_LROUND:
1019   case ISD::STRICT_LLROUND:
1020     // These pseudo-ops are the same as the other STRICT_ ops except
1021     // they are registered with setOperationAction() using the input type
1022     // instead of the output type.
1023     Action = TLI.getOperationAction(Node->getOpcode(),
1024                                     Node->getOperand(1).getValueType());
1025     break;
1026   case ISD::SIGN_EXTEND_INREG: {
1027     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1028     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1029     break;
1030   }
1031   case ISD::ATOMIC_STORE:
1032     Action = TLI.getOperationAction(Node->getOpcode(),
1033                                     Node->getOperand(2).getValueType());
1034     break;
1035   case ISD::SELECT_CC:
1036   case ISD::STRICT_FSETCC:
1037   case ISD::STRICT_FSETCCS:
1038   case ISD::SETCC:
1039   case ISD::BR_CC: {
1040     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1041                          Node->getOpcode() == ISD::STRICT_FSETCC ? 3 :
1042                          Node->getOpcode() == ISD::STRICT_FSETCCS ? 3 :
1043                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1044     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 :
1045                               Node->getOpcode() == ISD::STRICT_FSETCC ? 1 :
1046                               Node->getOpcode() == ISD::STRICT_FSETCCS ? 1 : 0;
1047     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1048     ISD::CondCode CCCode =
1049         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1050     Action = TLI.getCondCodeAction(CCCode, OpVT);
1051     if (Action == TargetLowering::Legal) {
1052       if (Node->getOpcode() == ISD::SELECT_CC)
1053         Action = TLI.getOperationAction(Node->getOpcode(),
1054                                         Node->getValueType(0));
1055       else
1056         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1057     }
1058     break;
1059   }
1060   case ISD::LOAD:
1061   case ISD::STORE:
1062     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1063     // STORE expects the unlegalized operand in some cases.
1064     SimpleFinishLegalizing = false;
1065     break;
1066   case ISD::CALLSEQ_START:
1067   case ISD::CALLSEQ_END:
1068     // FIXME: This shouldn't be necessary.  These nodes have special properties
1069     // dealing with the recursive nature of legalization.  Removing this
1070     // special case should be done as part of making LegalizeDAG non-recursive.
1071     SimpleFinishLegalizing = false;
1072     break;
1073   case ISD::EXTRACT_ELEMENT:
1074   case ISD::FLT_ROUNDS_:
1075   case ISD::MERGE_VALUES:
1076   case ISD::EH_RETURN:
1077   case ISD::FRAME_TO_ARGS_OFFSET:
1078   case ISD::EH_DWARF_CFA:
1079   case ISD::EH_SJLJ_SETJMP:
1080   case ISD::EH_SJLJ_LONGJMP:
1081   case ISD::EH_SJLJ_SETUP_DISPATCH:
1082     // These operations lie about being legal: when they claim to be legal,
1083     // they should actually be expanded.
1084     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1085     if (Action == TargetLowering::Legal)
1086       Action = TargetLowering::Expand;
1087     break;
1088   case ISD::INIT_TRAMPOLINE:
1089   case ISD::ADJUST_TRAMPOLINE:
1090   case ISD::FRAMEADDR:
1091   case ISD::RETURNADDR:
1092   case ISD::ADDROFRETURNADDR:
1093   case ISD::SPONENTRY:
1094     // These operations lie about being legal: when they claim to be legal,
1095     // they should actually be custom-lowered.
1096     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1097     if (Action == TargetLowering::Legal)
1098       Action = TargetLowering::Custom;
1099     break;
1100   case ISD::READCYCLECOUNTER:
1101     // READCYCLECOUNTER returns an i64, even if type legalization might have
1102     // expanded that to several smaller types.
1103     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1104     break;
1105   case ISD::READ_REGISTER:
1106   case ISD::WRITE_REGISTER:
1107     // Named register is legal in the DAG, but blocked by register name
1108     // selection if not implemented by target (to chose the correct register)
1109     // They'll be converted to Copy(To/From)Reg.
1110     Action = TargetLowering::Legal;
1111     break;
1112   case ISD::UBSANTRAP:
1113     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1114     if (Action == TargetLowering::Expand) {
1115       // replace ISD::UBSANTRAP with ISD::TRAP
1116       SDValue NewVal;
1117       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1118                            Node->getOperand(0));
1119       ReplaceNode(Node, NewVal.getNode());
1120       LegalizeOp(NewVal.getNode());
1121       return;
1122     }
1123     break;
1124   case ISD::DEBUGTRAP:
1125     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1126     if (Action == TargetLowering::Expand) {
1127       // replace ISD::DEBUGTRAP with ISD::TRAP
1128       SDValue NewVal;
1129       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1130                            Node->getOperand(0));
1131       ReplaceNode(Node, NewVal.getNode());
1132       LegalizeOp(NewVal.getNode());
1133       return;
1134     }
1135     break;
1136   case ISD::SADDSAT:
1137   case ISD::UADDSAT:
1138   case ISD::SSUBSAT:
1139   case ISD::USUBSAT:
1140   case ISD::SSHLSAT:
1141   case ISD::USHLSAT:
1142   case ISD::FP_TO_SINT_SAT:
1143   case ISD::FP_TO_UINT_SAT:
1144     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1145     break;
1146   case ISD::SMULFIX:
1147   case ISD::SMULFIXSAT:
1148   case ISD::UMULFIX:
1149   case ISD::UMULFIXSAT:
1150   case ISD::SDIVFIX:
1151   case ISD::SDIVFIXSAT:
1152   case ISD::UDIVFIX:
1153   case ISD::UDIVFIXSAT: {
1154     unsigned Scale = Node->getConstantOperandVal(2);
1155     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1156                                               Node->getValueType(0), Scale);
1157     break;
1158   }
1159   case ISD::MSCATTER:
1160     Action = TLI.getOperationAction(Node->getOpcode(),
1161                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1162     break;
1163   case ISD::MSTORE:
1164     Action = TLI.getOperationAction(Node->getOpcode(),
1165                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1166     break;
1167   case ISD::VP_SCATTER:
1168     Action = TLI.getOperationAction(
1169         Node->getOpcode(),
1170         cast<VPScatterSDNode>(Node)->getValue().getValueType());
1171     break;
1172   case ISD::VP_STORE:
1173     Action = TLI.getOperationAction(
1174         Node->getOpcode(),
1175         cast<VPStoreSDNode>(Node)->getValue().getValueType());
1176     break;
1177   case ISD::EXPERIMENTAL_VP_STRIDED_STORE:
1178     Action = TLI.getOperationAction(
1179         Node->getOpcode(),
1180         cast<VPStridedStoreSDNode>(Node)->getValue().getValueType());
1181     break;
1182   case ISD::VECREDUCE_FADD:
1183   case ISD::VECREDUCE_FMUL:
1184   case ISD::VECREDUCE_ADD:
1185   case ISD::VECREDUCE_MUL:
1186   case ISD::VECREDUCE_AND:
1187   case ISD::VECREDUCE_OR:
1188   case ISD::VECREDUCE_XOR:
1189   case ISD::VECREDUCE_SMAX:
1190   case ISD::VECREDUCE_SMIN:
1191   case ISD::VECREDUCE_UMAX:
1192   case ISD::VECREDUCE_UMIN:
1193   case ISD::VECREDUCE_FMAX:
1194   case ISD::VECREDUCE_FMIN:
1195     Action = TLI.getOperationAction(
1196         Node->getOpcode(), Node->getOperand(0).getValueType());
1197     break;
1198   case ISD::VECREDUCE_SEQ_FADD:
1199   case ISD::VECREDUCE_SEQ_FMUL:
1200   case ISD::VP_REDUCE_FADD:
1201   case ISD::VP_REDUCE_FMUL:
1202   case ISD::VP_REDUCE_ADD:
1203   case ISD::VP_REDUCE_MUL:
1204   case ISD::VP_REDUCE_AND:
1205   case ISD::VP_REDUCE_OR:
1206   case ISD::VP_REDUCE_XOR:
1207   case ISD::VP_REDUCE_SMAX:
1208   case ISD::VP_REDUCE_SMIN:
1209   case ISD::VP_REDUCE_UMAX:
1210   case ISD::VP_REDUCE_UMIN:
1211   case ISD::VP_REDUCE_FMAX:
1212   case ISD::VP_REDUCE_FMIN:
1213   case ISD::VP_REDUCE_SEQ_FADD:
1214   case ISD::VP_REDUCE_SEQ_FMUL:
1215     Action = TLI.getOperationAction(
1216         Node->getOpcode(), Node->getOperand(1).getValueType());
1217     break;
1218   default:
1219     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1220       Action = TLI.getCustomOperationAction(*Node);
1221     } else {
1222       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1223     }
1224     break;
1225   }
1226 
1227   if (SimpleFinishLegalizing) {
1228     SDNode *NewNode = Node;
1229     switch (Node->getOpcode()) {
1230     default: break;
1231     case ISD::SHL:
1232     case ISD::SRL:
1233     case ISD::SRA:
1234     case ISD::ROTL:
1235     case ISD::ROTR: {
1236       // Legalizing shifts/rotates requires adjusting the shift amount
1237       // to the appropriate width.
1238       SDValue Op0 = Node->getOperand(0);
1239       SDValue Op1 = Node->getOperand(1);
1240       if (!Op1.getValueType().isVector()) {
1241         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1242         // The getShiftAmountOperand() may create a new operand node or
1243         // return the existing one. If new operand is created we need
1244         // to update the parent node.
1245         // Do not try to legalize SAO here! It will be automatically legalized
1246         // in the next round.
1247         if (SAO != Op1)
1248           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1249       }
1250     }
1251     break;
1252     case ISD::FSHL:
1253     case ISD::FSHR:
1254     case ISD::SRL_PARTS:
1255     case ISD::SRA_PARTS:
1256     case ISD::SHL_PARTS: {
1257       // Legalizing shifts/rotates requires adjusting the shift amount
1258       // to the appropriate width.
1259       SDValue Op0 = Node->getOperand(0);
1260       SDValue Op1 = Node->getOperand(1);
1261       SDValue Op2 = Node->getOperand(2);
1262       if (!Op2.getValueType().isVector()) {
1263         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1264         // The getShiftAmountOperand() may create a new operand node or
1265         // return the existing one. If new operand is created we need
1266         // to update the parent node.
1267         if (SAO != Op2)
1268           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1269       }
1270       break;
1271     }
1272     }
1273 
1274     if (NewNode != Node) {
1275       ReplaceNode(Node, NewNode);
1276       Node = NewNode;
1277     }
1278     switch (Action) {
1279     case TargetLowering::Legal:
1280       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1281       return;
1282     case TargetLowering::Custom:
1283       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1284       // FIXME: The handling for custom lowering with multiple results is
1285       // a complete mess.
1286       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1287         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1288           return;
1289 
1290         if (Node->getNumValues() == 1) {
1291           // Verify the new types match the original. Glue is waived because
1292           // ISD::ADDC can be legalized by replacing Glue with an integer type.
1293           assert((Res.getValueType() == Node->getValueType(0) ||
1294                   Node->getValueType(0) == MVT::Glue) &&
1295                  "Type mismatch for custom legalized operation");
1296           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1297           // We can just directly replace this node with the lowered value.
1298           ReplaceNode(SDValue(Node, 0), Res);
1299           return;
1300         }
1301 
1302         SmallVector<SDValue, 8> ResultVals;
1303         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) {
1304           // Verify the new types match the original. Glue is waived because
1305           // ISD::ADDC can be legalized by replacing Glue with an integer type.
1306           assert((Res->getValueType(i) == Node->getValueType(i) ||
1307                   Node->getValueType(i) == MVT::Glue) &&
1308                  "Type mismatch for custom legalized operation");
1309           ResultVals.push_back(Res.getValue(i));
1310         }
1311         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1312         ReplaceNode(Node, ResultVals.data());
1313         return;
1314       }
1315       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1316       LLVM_FALLTHROUGH;
1317     case TargetLowering::Expand:
1318       if (ExpandNode(Node))
1319         return;
1320       LLVM_FALLTHROUGH;
1321     case TargetLowering::LibCall:
1322       ConvertNodeToLibcall(Node);
1323       return;
1324     case TargetLowering::Promote:
1325       PromoteNode(Node);
1326       return;
1327     }
1328   }
1329 
1330   switch (Node->getOpcode()) {
1331   default:
1332 #ifndef NDEBUG
1333     dbgs() << "NODE: ";
1334     Node->dump( &DAG);
1335     dbgs() << "\n";
1336 #endif
1337     llvm_unreachable("Do not know how to legalize this operator!");
1338 
1339   case ISD::CALLSEQ_START:
1340   case ISD::CALLSEQ_END:
1341     break;
1342   case ISD::LOAD:
1343     return LegalizeLoadOps(Node);
1344   case ISD::STORE:
1345     return LegalizeStoreOps(Node);
1346   }
1347 }
1348 
1349 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1350   SDValue Vec = Op.getOperand(0);
1351   SDValue Idx = Op.getOperand(1);
1352   SDLoc dl(Op);
1353 
1354   // Before we generate a new store to a temporary stack slot, see if there is
1355   // already one that we can use. There often is because when we scalarize
1356   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1357   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1358   // the vector. If all are expanded here, we don't want one store per vector
1359   // element.
1360 
1361   // Caches for hasPredecessorHelper
1362   SmallPtrSet<const SDNode *, 32> Visited;
1363   SmallVector<const SDNode *, 16> Worklist;
1364   Visited.insert(Op.getNode());
1365   Worklist.push_back(Idx.getNode());
1366   SDValue StackPtr, Ch;
1367   for (SDNode *User : Vec.getNode()->uses()) {
1368     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1369       if (ST->isIndexed() || ST->isTruncatingStore() ||
1370           ST->getValue() != Vec)
1371         continue;
1372 
1373       // Make sure that nothing else could have stored into the destination of
1374       // this store.
1375       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1376         continue;
1377 
1378       // If the index is dependent on the store we will introduce a cycle when
1379       // creating the load (the load uses the index, and by replacing the chain
1380       // we will make the index dependent on the load). Also, the store might be
1381       // dependent on the extractelement and introduce a cycle when creating
1382       // the load.
1383       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1384           ST->hasPredecessor(Op.getNode()))
1385         continue;
1386 
1387       StackPtr = ST->getBasePtr();
1388       Ch = SDValue(ST, 0);
1389       break;
1390     }
1391   }
1392 
1393   EVT VecVT = Vec.getValueType();
1394 
1395   if (!Ch.getNode()) {
1396     // Store the value to a temporary stack slot, then LOAD the returned part.
1397     StackPtr = DAG.CreateStackTemporary(VecVT);
1398     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1399                       MachinePointerInfo());
1400   }
1401 
1402   SDValue NewLoad;
1403 
1404   if (Op.getValueType().isVector()) {
1405     StackPtr = TLI.getVectorSubVecPointer(DAG, StackPtr, VecVT,
1406                                           Op.getValueType(), Idx);
1407     NewLoad =
1408         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1409   } else {
1410     StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1411     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1412                              MachinePointerInfo(),
1413                              VecVT.getVectorElementType());
1414   }
1415 
1416   // Replace the chain going out of the store, by the one out of the load.
1417   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1418 
1419   // We introduced a cycle though, so update the loads operands, making sure
1420   // to use the original store's chain as an incoming chain.
1421   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1422                                           NewLoad->op_end());
1423   NewLoadOperands[0] = Ch;
1424   NewLoad =
1425       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1426   return NewLoad;
1427 }
1428 
1429 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1430   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1431 
1432   SDValue Vec  = Op.getOperand(0);
1433   SDValue Part = Op.getOperand(1);
1434   SDValue Idx  = Op.getOperand(2);
1435   SDLoc dl(Op);
1436 
1437   // Store the value to a temporary stack slot, then LOAD the returned part.
1438   EVT VecVT = Vec.getValueType();
1439   EVT SubVecVT = Part.getValueType();
1440   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1441   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1442   MachinePointerInfo PtrInfo =
1443       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1444 
1445   // First store the whole vector.
1446   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1447 
1448   // Then store the inserted part.
1449   SDValue SubStackPtr =
1450       TLI.getVectorSubVecPointer(DAG, StackPtr, VecVT, SubVecVT, Idx);
1451 
1452   // Store the subvector.
1453   Ch = DAG.getStore(
1454       Ch, dl, Part, SubStackPtr,
1455       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()));
1456 
1457   // Finally, load the updated vector.
1458   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1459 }
1460 
1461 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1462   assert((Node->getOpcode() == ISD::BUILD_VECTOR ||
1463           Node->getOpcode() == ISD::CONCAT_VECTORS) &&
1464          "Unexpected opcode!");
1465 
1466   // We can't handle this case efficiently.  Allocate a sufficiently
1467   // aligned object on the stack, store each operand into it, then load
1468   // the result as a vector.
1469   // Create the stack frame object.
1470   EVT VT = Node->getValueType(0);
1471   EVT MemVT = isa<BuildVectorSDNode>(Node) ? VT.getVectorElementType()
1472                                            : Node->getOperand(0).getValueType();
1473   SDLoc dl(Node);
1474   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1475   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1476   MachinePointerInfo PtrInfo =
1477       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1478 
1479   // Emit a store of each element to the stack slot.
1480   SmallVector<SDValue, 8> Stores;
1481   unsigned TypeByteSize = MemVT.getSizeInBits() / 8;
1482   assert(TypeByteSize > 0 && "Vector element type too small for stack store!");
1483 
1484   // If the destination vector element type of a BUILD_VECTOR is narrower than
1485   // the source element type, only store the bits necessary.
1486   bool Truncate = isa<BuildVectorSDNode>(Node) &&
1487                   MemVT.bitsLT(Node->getOperand(0).getValueType());
1488 
1489   // Store (in the right endianness) the elements to memory.
1490   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1491     // Ignore undef elements.
1492     if (Node->getOperand(i).isUndef()) continue;
1493 
1494     unsigned Offset = TypeByteSize*i;
1495 
1496     SDValue Idx = DAG.getMemBasePlusOffset(FIPtr, TypeSize::Fixed(Offset), dl);
1497 
1498     if (Truncate)
1499       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1500                                          Node->getOperand(i), Idx,
1501                                          PtrInfo.getWithOffset(Offset), MemVT));
1502     else
1503       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1504                                     Idx, PtrInfo.getWithOffset(Offset)));
1505   }
1506 
1507   SDValue StoreChain;
1508   if (!Stores.empty())    // Not all undef elements?
1509     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1510   else
1511     StoreChain = DAG.getEntryNode();
1512 
1513   // Result is a load from the stack slot.
1514   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1515 }
1516 
1517 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1518 /// containing the sign bit if the target has no integer value capable of
1519 /// holding all bits of the floating-point value.
1520 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1521                                              const SDLoc &DL,
1522                                              SDValue Value) const {
1523   EVT FloatVT = Value.getValueType();
1524   unsigned NumBits = FloatVT.getScalarSizeInBits();
1525   State.FloatVT = FloatVT;
1526   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1527   // Convert to an integer of the same size.
1528   if (TLI.isTypeLegal(IVT)) {
1529     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1530     State.SignMask = APInt::getSignMask(NumBits);
1531     State.SignBit = NumBits - 1;
1532     return;
1533   }
1534 
1535   auto &DataLayout = DAG.getDataLayout();
1536   // Store the float to memory, then load the sign part out as an integer.
1537   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1538   // First create a temporary that is aligned for both the load and store.
1539   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1540   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1541   // Then store the float to it.
1542   State.FloatPtr = StackPtr;
1543   MachineFunction &MF = DAG.getMachineFunction();
1544   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1545   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1546                              State.FloatPointerInfo);
1547 
1548   SDValue IntPtr;
1549   if (DataLayout.isBigEndian()) {
1550     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1551     // Load out a legal integer with the same sign bit as the float.
1552     IntPtr = StackPtr;
1553     State.IntPointerInfo = State.FloatPointerInfo;
1554   } else {
1555     // Advance the pointer so that the loaded byte will contain the sign bit.
1556     unsigned ByteOffset = (NumBits / 8) - 1;
1557     IntPtr =
1558         DAG.getMemBasePlusOffset(StackPtr, TypeSize::Fixed(ByteOffset), DL);
1559     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1560                                                              ByteOffset);
1561   }
1562 
1563   State.IntPtr = IntPtr;
1564   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1565                                   State.IntPointerInfo, MVT::i8);
1566   State.SignMask = APInt::getOneBitSet(LoadTy.getScalarSizeInBits(), 7);
1567   State.SignBit = 7;
1568 }
1569 
1570 /// Replace the integer value produced by getSignAsIntValue() with a new value
1571 /// and cast the result back to a floating-point type.
1572 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1573                                               const SDLoc &DL,
1574                                               SDValue NewIntValue) const {
1575   if (!State.Chain)
1576     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1577 
1578   // Override the part containing the sign bit in the value stored on the stack.
1579   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1580                                     State.IntPointerInfo, MVT::i8);
1581   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1582                      State.FloatPointerInfo);
1583 }
1584 
1585 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1586   SDLoc DL(Node);
1587   SDValue Mag = Node->getOperand(0);
1588   SDValue Sign = Node->getOperand(1);
1589 
1590   // Get sign bit into an integer value.
1591   FloatSignAsInt SignAsInt;
1592   getSignAsIntValue(SignAsInt, DL, Sign);
1593 
1594   EVT IntVT = SignAsInt.IntValue.getValueType();
1595   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1596   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1597                                 SignMask);
1598 
1599   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1600   EVT FloatVT = Mag.getValueType();
1601   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1602       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1603     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1604     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1605     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1606                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1607     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1608   }
1609 
1610   // Transform Mag value to integer, and clear the sign bit.
1611   FloatSignAsInt MagAsInt;
1612   getSignAsIntValue(MagAsInt, DL, Mag);
1613   EVT MagVT = MagAsInt.IntValue.getValueType();
1614   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1615   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1616                                     ClearSignMask);
1617 
1618   // Get the signbit at the right position for MagAsInt.
1619   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1620   EVT ShiftVT = IntVT;
1621   if (SignBit.getScalarValueSizeInBits() <
1622       ClearedSign.getScalarValueSizeInBits()) {
1623     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1624     ShiftVT = MagVT;
1625   }
1626   if (ShiftAmount > 0) {
1627     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1628     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1629   } else if (ShiftAmount < 0) {
1630     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1631     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1632   }
1633   if (SignBit.getScalarValueSizeInBits() >
1634       ClearedSign.getScalarValueSizeInBits()) {
1635     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1636   }
1637 
1638   // Store the part with the modified sign and convert back to float.
1639   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1640   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1641 }
1642 
1643 SDValue SelectionDAGLegalize::ExpandFNEG(SDNode *Node) const {
1644   // Get the sign bit as an integer.
1645   SDLoc DL(Node);
1646   FloatSignAsInt SignAsInt;
1647   getSignAsIntValue(SignAsInt, DL, Node->getOperand(0));
1648   EVT IntVT = SignAsInt.IntValue.getValueType();
1649 
1650   // Flip the sign.
1651   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1652   SDValue SignFlip =
1653       DAG.getNode(ISD::XOR, DL, IntVT, SignAsInt.IntValue, SignMask);
1654 
1655   // Convert back to float.
1656   return modifySignAsInt(SignAsInt, DL, SignFlip);
1657 }
1658 
1659 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1660   SDLoc DL(Node);
1661   SDValue Value = Node->getOperand(0);
1662 
1663   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1664   EVT FloatVT = Value.getValueType();
1665   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1666     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1667     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1668   }
1669 
1670   // Transform value to integer, clear the sign bit and transform back.
1671   FloatSignAsInt ValueAsInt;
1672   getSignAsIntValue(ValueAsInt, DL, Value);
1673   EVT IntVT = ValueAsInt.IntValue.getValueType();
1674   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1675   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1676                                     ClearSignMask);
1677   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1678 }
1679 
1680 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1681                                            SmallVectorImpl<SDValue> &Results) {
1682   Register SPReg = TLI.getStackPointerRegisterToSaveRestore();
1683   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1684           " not tell us which reg is the stack pointer!");
1685   SDLoc dl(Node);
1686   EVT VT = Node->getValueType(0);
1687   SDValue Tmp1 = SDValue(Node, 0);
1688   SDValue Tmp2 = SDValue(Node, 1);
1689   SDValue Tmp3 = Node->getOperand(2);
1690   SDValue Chain = Tmp1.getOperand(0);
1691 
1692   // Chain the dynamic stack allocation so that it doesn't modify the stack
1693   // pointer when other instructions are using the stack.
1694   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1695 
1696   SDValue Size  = Tmp2.getOperand(1);
1697   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1698   Chain = SP.getValue(1);
1699   Align Alignment = cast<ConstantSDNode>(Tmp3)->getAlignValue();
1700   const TargetFrameLowering *TFL = DAG.getSubtarget().getFrameLowering();
1701   unsigned Opc =
1702     TFL->getStackGrowthDirection() == TargetFrameLowering::StackGrowsUp ?
1703     ISD::ADD : ISD::SUB;
1704 
1705   Align StackAlign = TFL->getStackAlign();
1706   Tmp1 = DAG.getNode(Opc, dl, VT, SP, Size);       // Value
1707   if (Alignment > StackAlign)
1708     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1709                        DAG.getConstant(-Alignment.value(), dl, VT));
1710   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1711 
1712   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1713                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1714 
1715   Results.push_back(Tmp1);
1716   Results.push_back(Tmp2);
1717 }
1718 
1719 /// Emit a store/load combination to the stack.  This stores
1720 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1721 /// a load from the stack slot to DestVT, extending it if needed.
1722 /// The resultant code need not be legal.
1723 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1724                                                EVT DestVT, const SDLoc &dl) {
1725   return EmitStackConvert(SrcOp, SlotVT, DestVT, dl, DAG.getEntryNode());
1726 }
1727 
1728 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1729                                                EVT DestVT, const SDLoc &dl,
1730                                                SDValue Chain) {
1731   unsigned SrcSize = SrcOp.getValueSizeInBits();
1732   unsigned SlotSize = SlotVT.getSizeInBits();
1733   unsigned DestSize = DestVT.getSizeInBits();
1734   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1735   Align DestAlign = DAG.getDataLayout().getPrefTypeAlign(DestType);
1736 
1737   // Don't convert with stack if the load/store is expensive.
1738   if ((SrcSize > SlotSize &&
1739        !TLI.isTruncStoreLegalOrCustom(SrcOp.getValueType(), SlotVT)) ||
1740       (SlotSize < DestSize &&
1741        !TLI.isLoadExtLegalOrCustom(ISD::EXTLOAD, DestVT, SlotVT)))
1742     return SDValue();
1743 
1744   // Create the stack frame object.
1745   Align SrcAlign = DAG.getDataLayout().getPrefTypeAlign(
1746       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1747   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT.getStoreSize(), SrcAlign);
1748 
1749   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1750   int SPFI = StackPtrFI->getIndex();
1751   MachinePointerInfo PtrInfo =
1752       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1753 
1754   // Emit a store to the stack slot.  Use a truncstore if the input value is
1755   // later than DestVT.
1756   SDValue Store;
1757 
1758   if (SrcSize > SlotSize)
1759     Store = DAG.getTruncStore(Chain, dl, SrcOp, FIPtr, PtrInfo,
1760                               SlotVT, SrcAlign);
1761   else {
1762     assert(SrcSize == SlotSize && "Invalid store");
1763     Store =
1764         DAG.getStore(Chain, dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1765   }
1766 
1767   // Result is a load from the stack slot.
1768   if (SlotSize == DestSize)
1769     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1770 
1771   assert(SlotSize < DestSize && "Unknown extension!");
1772   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1773                         DestAlign);
1774 }
1775 
1776 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1777   SDLoc dl(Node);
1778   // Create a vector sized/aligned stack slot, store the value to element #0,
1779   // then load the whole vector back out.
1780   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1781 
1782   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1783   int SPFI = StackPtrFI->getIndex();
1784 
1785   SDValue Ch = DAG.getTruncStore(
1786       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1787       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1788       Node->getValueType(0).getVectorElementType());
1789   return DAG.getLoad(
1790       Node->getValueType(0), dl, Ch, StackPtr,
1791       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1792 }
1793 
1794 static bool
1795 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1796                      const TargetLowering &TLI, SDValue &Res) {
1797   unsigned NumElems = Node->getNumOperands();
1798   SDLoc dl(Node);
1799   EVT VT = Node->getValueType(0);
1800 
1801   // Try to group the scalars into pairs, shuffle the pairs together, then
1802   // shuffle the pairs of pairs together, etc. until the vector has
1803   // been built. This will work only if all of the necessary shuffle masks
1804   // are legal.
1805 
1806   // We do this in two phases; first to check the legality of the shuffles,
1807   // and next, assuming that all shuffles are legal, to create the new nodes.
1808   for (int Phase = 0; Phase < 2; ++Phase) {
1809     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1810                                                               NewIntermedVals;
1811     for (unsigned i = 0; i < NumElems; ++i) {
1812       SDValue V = Node->getOperand(i);
1813       if (V.isUndef())
1814         continue;
1815 
1816       SDValue Vec;
1817       if (Phase)
1818         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1819       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1820     }
1821 
1822     while (IntermedVals.size() > 2) {
1823       NewIntermedVals.clear();
1824       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1825         // This vector and the next vector are shuffled together (simply to
1826         // append the one to the other).
1827         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1828 
1829         SmallVector<int, 16> FinalIndices;
1830         FinalIndices.reserve(IntermedVals[i].second.size() +
1831                              IntermedVals[i+1].second.size());
1832 
1833         int k = 0;
1834         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1835              ++j, ++k) {
1836           ShuffleVec[k] = j;
1837           FinalIndices.push_back(IntermedVals[i].second[j]);
1838         }
1839         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1840              ++j, ++k) {
1841           ShuffleVec[k] = NumElems + j;
1842           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1843         }
1844 
1845         SDValue Shuffle;
1846         if (Phase)
1847           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1848                                          IntermedVals[i+1].first,
1849                                          ShuffleVec);
1850         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1851           return false;
1852         NewIntermedVals.push_back(
1853             std::make_pair(Shuffle, std::move(FinalIndices)));
1854       }
1855 
1856       // If we had an odd number of defined values, then append the last
1857       // element to the array of new vectors.
1858       if ((IntermedVals.size() & 1) != 0)
1859         NewIntermedVals.push_back(IntermedVals.back());
1860 
1861       IntermedVals.swap(NewIntermedVals);
1862     }
1863 
1864     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1865            "Invalid number of intermediate vectors");
1866     SDValue Vec1 = IntermedVals[0].first;
1867     SDValue Vec2;
1868     if (IntermedVals.size() > 1)
1869       Vec2 = IntermedVals[1].first;
1870     else if (Phase)
1871       Vec2 = DAG.getUNDEF(VT);
1872 
1873     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1874     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1875       ShuffleVec[IntermedVals[0].second[i]] = i;
1876     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1877       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1878 
1879     if (Phase)
1880       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1881     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1882       return false;
1883   }
1884 
1885   return true;
1886 }
1887 
1888 /// Expand a BUILD_VECTOR node on targets that don't
1889 /// support the operation, but do support the resultant vector type.
1890 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1891   unsigned NumElems = Node->getNumOperands();
1892   SDValue Value1, Value2;
1893   SDLoc dl(Node);
1894   EVT VT = Node->getValueType(0);
1895   EVT OpVT = Node->getOperand(0).getValueType();
1896   EVT EltVT = VT.getVectorElementType();
1897 
1898   // If the only non-undef value is the low element, turn this into a
1899   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1900   bool isOnlyLowElement = true;
1901   bool MoreThanTwoValues = false;
1902   bool isConstant = true;
1903   for (unsigned i = 0; i < NumElems; ++i) {
1904     SDValue V = Node->getOperand(i);
1905     if (V.isUndef())
1906       continue;
1907     if (i > 0)
1908       isOnlyLowElement = false;
1909     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1910       isConstant = false;
1911 
1912     if (!Value1.getNode()) {
1913       Value1 = V;
1914     } else if (!Value2.getNode()) {
1915       if (V != Value1)
1916         Value2 = V;
1917     } else if (V != Value1 && V != Value2) {
1918       MoreThanTwoValues = true;
1919     }
1920   }
1921 
1922   if (!Value1.getNode())
1923     return DAG.getUNDEF(VT);
1924 
1925   if (isOnlyLowElement)
1926     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1927 
1928   // If all elements are constants, create a load from the constant pool.
1929   if (isConstant) {
1930     SmallVector<Constant*, 16> CV;
1931     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1932       if (ConstantFPSDNode *V =
1933           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1934         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1935       } else if (ConstantSDNode *V =
1936                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1937         if (OpVT==EltVT)
1938           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1939         else {
1940           // If OpVT and EltVT don't match, EltVT is not legal and the
1941           // element values have been promoted/truncated earlier.  Undo this;
1942           // we don't want a v16i8 to become a v16i32 for example.
1943           const ConstantInt *CI = V->getConstantIntValue();
1944           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1945                                         CI->getZExtValue()));
1946         }
1947       } else {
1948         assert(Node->getOperand(i).isUndef());
1949         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1950         CV.push_back(UndefValue::get(OpNTy));
1951       }
1952     }
1953     Constant *CP = ConstantVector::get(CV);
1954     SDValue CPIdx =
1955         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1956     Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
1957     return DAG.getLoad(
1958         VT, dl, DAG.getEntryNode(), CPIdx,
1959         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1960         Alignment);
1961   }
1962 
1963   SmallSet<SDValue, 16> DefinedValues;
1964   for (unsigned i = 0; i < NumElems; ++i) {
1965     if (Node->getOperand(i).isUndef())
1966       continue;
1967     DefinedValues.insert(Node->getOperand(i));
1968   }
1969 
1970   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1971     if (!MoreThanTwoValues) {
1972       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1973       for (unsigned i = 0; i < NumElems; ++i) {
1974         SDValue V = Node->getOperand(i);
1975         if (V.isUndef())
1976           continue;
1977         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1978       }
1979       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1980         // Get the splatted value into the low element of a vector register.
1981         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1982         SDValue Vec2;
1983         if (Value2.getNode())
1984           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
1985         else
1986           Vec2 = DAG.getUNDEF(VT);
1987 
1988         // Return shuffle(LowValVec, undef, <0,0,0,0>)
1989         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1990       }
1991     } else {
1992       SDValue Res;
1993       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
1994         return Res;
1995     }
1996   }
1997 
1998   // Otherwise, we can't handle this case efficiently.
1999   return ExpandVectorBuildThroughStack(Node);
2000 }
2001 
2002 SDValue SelectionDAGLegalize::ExpandSPLAT_VECTOR(SDNode *Node) {
2003   SDLoc DL(Node);
2004   EVT VT = Node->getValueType(0);
2005   SDValue SplatVal = Node->getOperand(0);
2006 
2007   return DAG.getSplatBuildVector(VT, DL, SplatVal);
2008 }
2009 
2010 // Expand a node into a call to a libcall.  If the result value
2011 // does not fit into a register, return the lo part and set the hi part to the
2012 // by-reg argument.  If it does fit into a single register, return the result
2013 // and leave the Hi part unset.
2014 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
2015                                             bool isSigned) {
2016   TargetLowering::ArgListTy Args;
2017   TargetLowering::ArgListEntry Entry;
2018   for (const SDValue &Op : Node->op_values()) {
2019     EVT ArgVT = Op.getValueType();
2020     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2021     Entry.Node = Op;
2022     Entry.Ty = ArgTy;
2023     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2024     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2025     Args.push_back(Entry);
2026   }
2027   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2028                                          TLI.getPointerTy(DAG.getDataLayout()));
2029 
2030   EVT RetVT = Node->getValueType(0);
2031   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2032 
2033   // By default, the input chain to this libcall is the entry node of the
2034   // function. If the libcall is going to be emitted as a tail call then
2035   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2036   // node which is being folded has a non-entry input chain.
2037   SDValue InChain = DAG.getEntryNode();
2038 
2039   // isTailCall may be true since the callee does not reference caller stack
2040   // frame. Check if it's in the right position and that the return types match.
2041   SDValue TCChain = InChain;
2042   const Function &F = DAG.getMachineFunction().getFunction();
2043   bool isTailCall =
2044       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2045       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2046   if (isTailCall)
2047     InChain = TCChain;
2048 
2049   TargetLowering::CallLoweringInfo CLI(DAG);
2050   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2051   CLI.setDebugLoc(SDLoc(Node))
2052       .setChain(InChain)
2053       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2054                     std::move(Args))
2055       .setTailCall(isTailCall)
2056       .setSExtResult(signExtend)
2057       .setZExtResult(!signExtend)
2058       .setIsPostTypeLegalization(true);
2059 
2060   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2061 
2062   if (!CallInfo.second.getNode()) {
2063     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump(&DAG));
2064     // It's a tailcall, return the chain (which is the DAG root).
2065     return DAG.getRoot();
2066   }
2067 
2068   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump(&DAG));
2069   return CallInfo.first;
2070 }
2071 
2072 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2073                                            RTLIB::Libcall LC,
2074                                            SmallVectorImpl<SDValue> &Results) {
2075   if (LC == RTLIB::UNKNOWN_LIBCALL)
2076     llvm_unreachable("Can't create an unknown libcall!");
2077 
2078   if (Node->isStrictFPOpcode()) {
2079     EVT RetVT = Node->getValueType(0);
2080     SmallVector<SDValue, 4> Ops(drop_begin(Node->ops()));
2081     TargetLowering::MakeLibCallOptions CallOptions;
2082     // FIXME: This doesn't support tail calls.
2083     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2084                                                       Ops, CallOptions,
2085                                                       SDLoc(Node),
2086                                                       Node->getOperand(0));
2087     Results.push_back(Tmp.first);
2088     Results.push_back(Tmp.second);
2089   } else {
2090     SDValue Tmp = ExpandLibCall(LC, Node, false);
2091     Results.push_back(Tmp);
2092   }
2093 }
2094 
2095 /// Expand the node to a libcall based on the result type.
2096 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2097                                            RTLIB::Libcall Call_F32,
2098                                            RTLIB::Libcall Call_F64,
2099                                            RTLIB::Libcall Call_F80,
2100                                            RTLIB::Libcall Call_F128,
2101                                            RTLIB::Libcall Call_PPCF128,
2102                                            SmallVectorImpl<SDValue> &Results) {
2103   RTLIB::Libcall LC = RTLIB::getFPLibCall(Node->getSimpleValueType(0),
2104                                           Call_F32, Call_F64, Call_F80,
2105                                           Call_F128, Call_PPCF128);
2106   ExpandFPLibCall(Node, LC, Results);
2107 }
2108 
2109 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2110                                                RTLIB::Libcall Call_I8,
2111                                                RTLIB::Libcall Call_I16,
2112                                                RTLIB::Libcall Call_I32,
2113                                                RTLIB::Libcall Call_I64,
2114                                                RTLIB::Libcall Call_I128) {
2115   RTLIB::Libcall LC;
2116   switch (Node->getSimpleValueType(0).SimpleTy) {
2117   default: llvm_unreachable("Unexpected request for libcall!");
2118   case MVT::i8:   LC = Call_I8; break;
2119   case MVT::i16:  LC = Call_I16; break;
2120   case MVT::i32:  LC = Call_I32; break;
2121   case MVT::i64:  LC = Call_I64; break;
2122   case MVT::i128: LC = Call_I128; break;
2123   }
2124   return ExpandLibCall(LC, Node, isSigned);
2125 }
2126 
2127 /// Expand the node to a libcall based on first argument type (for instance
2128 /// lround and its variant).
2129 void SelectionDAGLegalize::ExpandArgFPLibCall(SDNode* Node,
2130                                             RTLIB::Libcall Call_F32,
2131                                             RTLIB::Libcall Call_F64,
2132                                             RTLIB::Libcall Call_F80,
2133                                             RTLIB::Libcall Call_F128,
2134                                             RTLIB::Libcall Call_PPCF128,
2135                                             SmallVectorImpl<SDValue> &Results) {
2136   EVT InVT = Node->getOperand(Node->isStrictFPOpcode() ? 1 : 0).getValueType();
2137   RTLIB::Libcall LC = RTLIB::getFPLibCall(InVT.getSimpleVT(),
2138                                           Call_F32, Call_F64, Call_F80,
2139                                           Call_F128, Call_PPCF128);
2140   ExpandFPLibCall(Node, LC, Results);
2141 }
2142 
2143 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2144 void
2145 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2146                                           SmallVectorImpl<SDValue> &Results) {
2147   unsigned Opcode = Node->getOpcode();
2148   bool isSigned = Opcode == ISD::SDIVREM;
2149 
2150   RTLIB::Libcall LC;
2151   switch (Node->getSimpleValueType(0).SimpleTy) {
2152   default: llvm_unreachable("Unexpected request for libcall!");
2153   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2154   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2155   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2156   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2157   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2158   }
2159 
2160   // The input chain to this libcall is the entry node of the function.
2161   // Legalizing the call will automatically add the previous call to the
2162   // dependence.
2163   SDValue InChain = DAG.getEntryNode();
2164 
2165   EVT RetVT = Node->getValueType(0);
2166   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2167 
2168   TargetLowering::ArgListTy Args;
2169   TargetLowering::ArgListEntry Entry;
2170   for (const SDValue &Op : Node->op_values()) {
2171     EVT ArgVT = Op.getValueType();
2172     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2173     Entry.Node = Op;
2174     Entry.Ty = ArgTy;
2175     Entry.IsSExt = isSigned;
2176     Entry.IsZExt = !isSigned;
2177     Args.push_back(Entry);
2178   }
2179 
2180   // Also pass the return address of the remainder.
2181   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2182   Entry.Node = FIPtr;
2183   Entry.Ty = RetTy->getPointerTo();
2184   Entry.IsSExt = isSigned;
2185   Entry.IsZExt = !isSigned;
2186   Args.push_back(Entry);
2187 
2188   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2189                                          TLI.getPointerTy(DAG.getDataLayout()));
2190 
2191   SDLoc dl(Node);
2192   TargetLowering::CallLoweringInfo CLI(DAG);
2193   CLI.setDebugLoc(dl)
2194       .setChain(InChain)
2195       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2196                     std::move(Args))
2197       .setSExtResult(isSigned)
2198       .setZExtResult(!isSigned);
2199 
2200   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2201 
2202   // Remainder is loaded back from the stack frame.
2203   SDValue Rem =
2204       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2205   Results.push_back(CallInfo.first);
2206   Results.push_back(Rem);
2207 }
2208 
2209 /// Return true if sincos libcall is available.
2210 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2211   RTLIB::Libcall LC;
2212   switch (Node->getSimpleValueType(0).SimpleTy) {
2213   default: llvm_unreachable("Unexpected request for libcall!");
2214   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2215   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2216   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2217   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2218   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2219   }
2220   return TLI.getLibcallName(LC) != nullptr;
2221 }
2222 
2223 /// Only issue sincos libcall if both sin and cos are needed.
2224 static bool useSinCos(SDNode *Node) {
2225   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2226     ? ISD::FCOS : ISD::FSIN;
2227 
2228   SDValue Op0 = Node->getOperand(0);
2229   for (const SDNode *User : Op0.getNode()->uses()) {
2230     if (User == Node)
2231       continue;
2232     // The other user might have been turned into sincos already.
2233     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2234       return true;
2235   }
2236   return false;
2237 }
2238 
2239 /// Issue libcalls to sincos to compute sin / cos pairs.
2240 void
2241 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2242                                           SmallVectorImpl<SDValue> &Results) {
2243   RTLIB::Libcall LC;
2244   switch (Node->getSimpleValueType(0).SimpleTy) {
2245   default: llvm_unreachable("Unexpected request for libcall!");
2246   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2247   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2248   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2249   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2250   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2251   }
2252 
2253   // The input chain to this libcall is the entry node of the function.
2254   // Legalizing the call will automatically add the previous call to the
2255   // dependence.
2256   SDValue InChain = DAG.getEntryNode();
2257 
2258   EVT RetVT = Node->getValueType(0);
2259   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2260 
2261   TargetLowering::ArgListTy Args;
2262   TargetLowering::ArgListEntry Entry;
2263 
2264   // Pass the argument.
2265   Entry.Node = Node->getOperand(0);
2266   Entry.Ty = RetTy;
2267   Entry.IsSExt = false;
2268   Entry.IsZExt = false;
2269   Args.push_back(Entry);
2270 
2271   // Pass the return address of sin.
2272   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2273   Entry.Node = SinPtr;
2274   Entry.Ty = RetTy->getPointerTo();
2275   Entry.IsSExt = false;
2276   Entry.IsZExt = false;
2277   Args.push_back(Entry);
2278 
2279   // Also pass the return address of the cos.
2280   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2281   Entry.Node = CosPtr;
2282   Entry.Ty = RetTy->getPointerTo();
2283   Entry.IsSExt = false;
2284   Entry.IsZExt = false;
2285   Args.push_back(Entry);
2286 
2287   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2288                                          TLI.getPointerTy(DAG.getDataLayout()));
2289 
2290   SDLoc dl(Node);
2291   TargetLowering::CallLoweringInfo CLI(DAG);
2292   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2293       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2294       std::move(Args));
2295 
2296   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2297 
2298   Results.push_back(
2299       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2300   Results.push_back(
2301       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2302 }
2303 
2304 /// This function is responsible for legalizing a
2305 /// INT_TO_FP operation of the specified operand when the target requests that
2306 /// we expand it.  At this point, we know that the result and operand types are
2307 /// legal for the target.
2308 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(SDNode *Node,
2309                                                    SDValue &Chain) {
2310   bool isSigned = (Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
2311                    Node->getOpcode() == ISD::SINT_TO_FP);
2312   EVT DestVT = Node->getValueType(0);
2313   SDLoc dl(Node);
2314   unsigned OpNo = Node->isStrictFPOpcode() ? 1 : 0;
2315   SDValue Op0 = Node->getOperand(OpNo);
2316   EVT SrcVT = Op0.getValueType();
2317 
2318   // TODO: Should any fast-math-flags be set for the created nodes?
2319   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2320   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64) &&
2321       (DestVT.bitsLE(MVT::f64) ||
2322        TLI.isOperationLegal(Node->isStrictFPOpcode() ? ISD::STRICT_FP_EXTEND
2323                                                      : ISD::FP_EXTEND,
2324                             DestVT))) {
2325     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2326                          "expansion\n");
2327 
2328     // Get the stack frame index of a 8 byte buffer.
2329     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2330 
2331     SDValue Lo = Op0;
2332     // if signed map to unsigned space
2333     if (isSigned) {
2334       // Invert sign bit (signed to unsigned mapping).
2335       Lo = DAG.getNode(ISD::XOR, dl, MVT::i32, Lo,
2336                        DAG.getConstant(0x80000000u, dl, MVT::i32));
2337     }
2338     // Initial hi portion of constructed double.
2339     SDValue Hi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2340 
2341     // If this a big endian target, swap the lo and high data.
2342     if (DAG.getDataLayout().isBigEndian())
2343       std::swap(Lo, Hi);
2344 
2345     SDValue MemChain = DAG.getEntryNode();
2346 
2347     // Store the lo of the constructed double.
2348     SDValue Store1 = DAG.getStore(MemChain, dl, Lo, StackSlot,
2349                                   MachinePointerInfo());
2350     // Store the hi of the constructed double.
2351     SDValue HiPtr = DAG.getMemBasePlusOffset(StackSlot, TypeSize::Fixed(4), dl);
2352     SDValue Store2 =
2353         DAG.getStore(MemChain, dl, Hi, HiPtr, MachinePointerInfo());
2354     MemChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
2355 
2356     // load the constructed double
2357     SDValue Load =
2358         DAG.getLoad(MVT::f64, dl, MemChain, StackSlot, MachinePointerInfo());
2359     // FP constant to bias correct the final result
2360     SDValue Bias = DAG.getConstantFP(isSigned ?
2361                                      BitsToDouble(0x4330000080000000ULL) :
2362                                      BitsToDouble(0x4330000000000000ULL),
2363                                      dl, MVT::f64);
2364     // Subtract the bias and get the final result.
2365     SDValue Sub;
2366     SDValue Result;
2367     if (Node->isStrictFPOpcode()) {
2368       Sub = DAG.getNode(ISD::STRICT_FSUB, dl, {MVT::f64, MVT::Other},
2369                         {Node->getOperand(0), Load, Bias});
2370       Chain = Sub.getValue(1);
2371       if (DestVT != Sub.getValueType()) {
2372         std::pair<SDValue, SDValue> ResultPair;
2373         ResultPair =
2374             DAG.getStrictFPExtendOrRound(Sub, Chain, dl, DestVT);
2375         Result = ResultPair.first;
2376         Chain = ResultPair.second;
2377       }
2378       else
2379         Result = Sub;
2380     } else {
2381       Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2382       Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2383     }
2384     return Result;
2385   }
2386 
2387   if (isSigned)
2388     return SDValue();
2389 
2390   // TODO: Generalize this for use with other types.
2391   if (((SrcVT == MVT::i32 || SrcVT == MVT::i64) && DestVT == MVT::f32) ||
2392       (SrcVT == MVT::i64 && DestVT == MVT::f64)) {
2393     LLVM_DEBUG(dbgs() << "Converting unsigned i32/i64 to f32/f64\n");
2394     // For unsigned conversions, convert them to signed conversions using the
2395     // algorithm from the x86_64 __floatundisf in compiler_rt. That method
2396     // should be valid for i32->f32 as well.
2397 
2398     // More generally this transform should be valid if there are 3 more bits
2399     // in the integer type than the significand. Rounding uses the first bit
2400     // after the width of the significand and the OR of all bits after that. So
2401     // we need to be able to OR the shifted out bit into one of the bits that
2402     // participate in the OR.
2403 
2404     // TODO: This really should be implemented using a branch rather than a
2405     // select.  We happen to get lucky and machinesink does the right
2406     // thing most of the time.  This would be a good candidate for a
2407     // pseudo-op, or, even better, for whole-function isel.
2408     EVT SetCCVT = getSetCCResultType(SrcVT);
2409 
2410     SDValue SignBitTest = DAG.getSetCC(
2411         dl, SetCCVT, Op0, DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2412 
2413     EVT ShiftVT = TLI.getShiftAmountTy(SrcVT, DAG.getDataLayout());
2414     SDValue ShiftConst = DAG.getConstant(1, dl, ShiftVT);
2415     SDValue Shr = DAG.getNode(ISD::SRL, dl, SrcVT, Op0, ShiftConst);
2416     SDValue AndConst = DAG.getConstant(1, dl, SrcVT);
2417     SDValue And = DAG.getNode(ISD::AND, dl, SrcVT, Op0, AndConst);
2418     SDValue Or = DAG.getNode(ISD::OR, dl, SrcVT, And, Shr);
2419 
2420     SDValue Slow, Fast;
2421     if (Node->isStrictFPOpcode()) {
2422       // In strict mode, we must avoid spurious exceptions, and therefore
2423       // must make sure to only emit a single STRICT_SINT_TO_FP.
2424       SDValue InCvt = DAG.getSelect(dl, SrcVT, SignBitTest, Or, Op0);
2425       Fast = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2426                          { Node->getOperand(0), InCvt });
2427       Slow = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2428                          { Fast.getValue(1), Fast, Fast });
2429       Chain = Slow.getValue(1);
2430       // The STRICT_SINT_TO_FP inherits the exception mode from the
2431       // incoming STRICT_UINT_TO_FP node; the STRICT_FADD node can
2432       // never raise any exception.
2433       SDNodeFlags Flags;
2434       Flags.setNoFPExcept(Node->getFlags().hasNoFPExcept());
2435       Fast->setFlags(Flags);
2436       Flags.setNoFPExcept(true);
2437       Slow->setFlags(Flags);
2438     } else {
2439       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Or);
2440       Slow = DAG.getNode(ISD::FADD, dl, DestVT, SignCvt, SignCvt);
2441       Fast = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2442     }
2443 
2444     return DAG.getSelect(dl, DestVT, SignBitTest, Slow, Fast);
2445   }
2446 
2447   // Don't expand it if there isn't cheap fadd.
2448   if (!TLI.isOperationLegalOrCustom(
2449           Node->isStrictFPOpcode() ? ISD::STRICT_FADD : ISD::FADD, DestVT))
2450     return SDValue();
2451 
2452   // The following optimization is valid only if every value in SrcVT (when
2453   // treated as signed) is representable in DestVT.  Check that the mantissa
2454   // size of DestVT is >= than the number of bits in SrcVT -1.
2455   assert(APFloat::semanticsPrecision(DAG.EVTToAPFloatSemantics(DestVT)) >=
2456              SrcVT.getSizeInBits() - 1 &&
2457          "Cannot perform lossless SINT_TO_FP!");
2458 
2459   SDValue Tmp1;
2460   if (Node->isStrictFPOpcode()) {
2461     Tmp1 = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2462                        { Node->getOperand(0), Op0 });
2463   } else
2464     Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2465 
2466   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2467                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2468   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2469           Four = DAG.getIntPtrConstant(4, dl);
2470   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2471                                     SignSet, Four, Zero);
2472 
2473   // If the sign bit of the integer is set, the large number will be treated
2474   // as a negative number.  To counteract this, the dynamic code adds an
2475   // offset depending on the data type.
2476   uint64_t FF;
2477   switch (SrcVT.getSimpleVT().SimpleTy) {
2478   default:
2479     return SDValue();
2480   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2481   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2482   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2483   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2484   }
2485   if (DAG.getDataLayout().isLittleEndian())
2486     FF <<= 32;
2487   Constant *FudgeFactor = ConstantInt::get(
2488                                        Type::getInt64Ty(*DAG.getContext()), FF);
2489 
2490   SDValue CPIdx =
2491       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2492   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
2493   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2494   Alignment = commonAlignment(Alignment, 4);
2495   SDValue FudgeInReg;
2496   if (DestVT == MVT::f32)
2497     FudgeInReg = DAG.getLoad(
2498         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2499         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2500         Alignment);
2501   else {
2502     SDValue Load = DAG.getExtLoad(
2503         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2504         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2505         Alignment);
2506     HandleSDNode Handle(Load);
2507     LegalizeOp(Load.getNode());
2508     FudgeInReg = Handle.getValue();
2509   }
2510 
2511   if (Node->isStrictFPOpcode()) {
2512     SDValue Result = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2513                                  { Tmp1.getValue(1), Tmp1, FudgeInReg });
2514     Chain = Result.getValue(1);
2515     return Result;
2516   }
2517 
2518   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2519 }
2520 
2521 /// This function is responsible for legalizing a
2522 /// *INT_TO_FP operation of the specified operand when the target requests that
2523 /// we promote it.  At this point, we know that the result and operand types are
2524 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2525 /// operation that takes a larger input.
2526 void SelectionDAGLegalize::PromoteLegalINT_TO_FP(
2527     SDNode *N, const SDLoc &dl, SmallVectorImpl<SDValue> &Results) {
2528   bool IsStrict = N->isStrictFPOpcode();
2529   bool IsSigned = N->getOpcode() == ISD::SINT_TO_FP ||
2530                   N->getOpcode() == ISD::STRICT_SINT_TO_FP;
2531   EVT DestVT = N->getValueType(0);
2532   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2533   unsigned UIntOp = IsStrict ? ISD::STRICT_UINT_TO_FP : ISD::UINT_TO_FP;
2534   unsigned SIntOp = IsStrict ? ISD::STRICT_SINT_TO_FP : ISD::SINT_TO_FP;
2535 
2536   // First step, figure out the appropriate *INT_TO_FP operation to use.
2537   EVT NewInTy = LegalOp.getValueType();
2538 
2539   unsigned OpToUse = 0;
2540 
2541   // Scan for the appropriate larger type to use.
2542   while (true) {
2543     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2544     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2545 
2546     // If the target supports SINT_TO_FP of this type, use it.
2547     if (TLI.isOperationLegalOrCustom(SIntOp, NewInTy)) {
2548       OpToUse = SIntOp;
2549       break;
2550     }
2551     if (IsSigned)
2552       continue;
2553 
2554     // If the target supports UINT_TO_FP of this type, use it.
2555     if (TLI.isOperationLegalOrCustom(UIntOp, NewInTy)) {
2556       OpToUse = UIntOp;
2557       break;
2558     }
2559 
2560     // Otherwise, try a larger type.
2561   }
2562 
2563   // Okay, we found the operation and type to use.  Zero extend our input to the
2564   // desired type then run the operation on it.
2565   if (IsStrict) {
2566     SDValue Res =
2567         DAG.getNode(OpToUse, dl, {DestVT, MVT::Other},
2568                     {N->getOperand(0),
2569                      DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2570                                  dl, NewInTy, LegalOp)});
2571     Results.push_back(Res);
2572     Results.push_back(Res.getValue(1));
2573     return;
2574   }
2575 
2576   Results.push_back(
2577       DAG.getNode(OpToUse, dl, DestVT,
2578                   DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2579                               dl, NewInTy, LegalOp)));
2580 }
2581 
2582 /// This function is responsible for legalizing a
2583 /// FP_TO_*INT operation of the specified operand when the target requests that
2584 /// we promote it.  At this point, we know that the result and operand types are
2585 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2586 /// operation that returns a larger result.
2587 void SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
2588                                                  SmallVectorImpl<SDValue> &Results) {
2589   bool IsStrict = N->isStrictFPOpcode();
2590   bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT ||
2591                   N->getOpcode() == ISD::STRICT_FP_TO_SINT;
2592   EVT DestVT = N->getValueType(0);
2593   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2594   // First step, figure out the appropriate FP_TO*INT operation to use.
2595   EVT NewOutTy = DestVT;
2596 
2597   unsigned OpToUse = 0;
2598 
2599   // Scan for the appropriate larger type to use.
2600   while (true) {
2601     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2602     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2603 
2604     // A larger signed type can hold all unsigned values of the requested type,
2605     // so using FP_TO_SINT is valid
2606     OpToUse = IsStrict ? ISD::STRICT_FP_TO_SINT : ISD::FP_TO_SINT;
2607     if (TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2608       break;
2609 
2610     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2611     OpToUse = IsStrict ? ISD::STRICT_FP_TO_UINT : ISD::FP_TO_UINT;
2612     if (!IsSigned && TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2613       break;
2614 
2615     // Otherwise, try a larger type.
2616   }
2617 
2618   // Okay, we found the operation and type to use.
2619   SDValue Operation;
2620   if (IsStrict) {
2621     SDVTList VTs = DAG.getVTList(NewOutTy, MVT::Other);
2622     Operation = DAG.getNode(OpToUse, dl, VTs, N->getOperand(0), LegalOp);
2623   } else
2624     Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2625 
2626   // Truncate the result of the extended FP_TO_*INT operation to the desired
2627   // size.
2628   SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2629   Results.push_back(Trunc);
2630   if (IsStrict)
2631     Results.push_back(Operation.getValue(1));
2632 }
2633 
2634 /// Promote FP_TO_*INT_SAT operation to a larger result type. At this point
2635 /// the result and operand types are legal and there must be a legal
2636 /// FP_TO_*INT_SAT operation for a larger result type.
2637 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT_SAT(SDNode *Node,
2638                                                         const SDLoc &dl) {
2639   unsigned Opcode = Node->getOpcode();
2640 
2641   // Scan for the appropriate larger type to use.
2642   EVT NewOutTy = Node->getValueType(0);
2643   while (true) {
2644     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy + 1);
2645     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2646 
2647     if (TLI.isOperationLegalOrCustom(Opcode, NewOutTy))
2648       break;
2649   }
2650 
2651   // Saturation width is determined by second operand, so we don't have to
2652   // perform any fixup and can directly truncate the result.
2653   SDValue Result = DAG.getNode(Opcode, dl, NewOutTy, Node->getOperand(0),
2654                                Node->getOperand(1));
2655   return DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Result);
2656 }
2657 
2658 /// Open code the operations for PARITY of the specified operation.
2659 SDValue SelectionDAGLegalize::ExpandPARITY(SDValue Op, const SDLoc &dl) {
2660   EVT VT = Op.getValueType();
2661   EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2662   unsigned Sz = VT.getScalarSizeInBits();
2663 
2664   // If CTPOP is legal, use it. Otherwise use shifts and xor.
2665   SDValue Result;
2666   if (TLI.isOperationLegalOrPromote(ISD::CTPOP, VT)) {
2667     Result = DAG.getNode(ISD::CTPOP, dl, VT, Op);
2668   } else {
2669     Result = Op;
2670     for (unsigned i = Log2_32_Ceil(Sz); i != 0;) {
2671       SDValue Shift = DAG.getNode(ISD::SRL, dl, VT, Result,
2672                                   DAG.getConstant(1ULL << (--i), dl, ShVT));
2673       Result = DAG.getNode(ISD::XOR, dl, VT, Result, Shift);
2674     }
2675   }
2676 
2677   return DAG.getNode(ISD::AND, dl, VT, Result, DAG.getConstant(1, dl, VT));
2678 }
2679 
2680 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2681   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2682   SmallVector<SDValue, 8> Results;
2683   SDLoc dl(Node);
2684   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2685   bool NeedInvert;
2686   switch (Node->getOpcode()) {
2687   case ISD::ABS:
2688     if ((Tmp1 = TLI.expandABS(Node, DAG)))
2689       Results.push_back(Tmp1);
2690     break;
2691   case ISD::CTPOP:
2692     if ((Tmp1 = TLI.expandCTPOP(Node, DAG)))
2693       Results.push_back(Tmp1);
2694     break;
2695   case ISD::CTLZ:
2696   case ISD::CTLZ_ZERO_UNDEF:
2697     if ((Tmp1 = TLI.expandCTLZ(Node, DAG)))
2698       Results.push_back(Tmp1);
2699     break;
2700   case ISD::CTTZ:
2701   case ISD::CTTZ_ZERO_UNDEF:
2702     if ((Tmp1 = TLI.expandCTTZ(Node, DAG)))
2703       Results.push_back(Tmp1);
2704     break;
2705   case ISD::BITREVERSE:
2706     if ((Tmp1 = TLI.expandBITREVERSE(Node, DAG)))
2707       Results.push_back(Tmp1);
2708     break;
2709   case ISD::BSWAP:
2710     if ((Tmp1 = TLI.expandBSWAP(Node, DAG)))
2711       Results.push_back(Tmp1);
2712     break;
2713   case ISD::PARITY:
2714     Results.push_back(ExpandPARITY(Node->getOperand(0), dl));
2715     break;
2716   case ISD::FRAMEADDR:
2717   case ISD::RETURNADDR:
2718   case ISD::FRAME_TO_ARGS_OFFSET:
2719     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2720     break;
2721   case ISD::EH_DWARF_CFA: {
2722     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2723                                         TLI.getPointerTy(DAG.getDataLayout()));
2724     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2725                                  CfaArg.getValueType(),
2726                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2727                                              CfaArg.getValueType()),
2728                                  CfaArg);
2729     SDValue FA = DAG.getNode(
2730         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2731         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2732     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2733                                   FA, Offset));
2734     break;
2735   }
2736   case ISD::FLT_ROUNDS_:
2737     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2738     Results.push_back(Node->getOperand(0));
2739     break;
2740   case ISD::EH_RETURN:
2741   case ISD::EH_LABEL:
2742   case ISD::PREFETCH:
2743   case ISD::VAEND:
2744   case ISD::EH_SJLJ_LONGJMP:
2745     // If the target didn't expand these, there's nothing to do, so just
2746     // preserve the chain and be done.
2747     Results.push_back(Node->getOperand(0));
2748     break;
2749   case ISD::READCYCLECOUNTER:
2750     // If the target didn't expand this, just return 'zero' and preserve the
2751     // chain.
2752     Results.append(Node->getNumValues() - 1,
2753                    DAG.getConstant(0, dl, Node->getValueType(0)));
2754     Results.push_back(Node->getOperand(0));
2755     break;
2756   case ISD::EH_SJLJ_SETJMP:
2757     // If the target didn't expand this, just return 'zero' and preserve the
2758     // chain.
2759     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2760     Results.push_back(Node->getOperand(0));
2761     break;
2762   case ISD::ATOMIC_LOAD: {
2763     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2764     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2765     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2766     SDValue Swap = DAG.getAtomicCmpSwap(
2767         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2768         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2769         cast<AtomicSDNode>(Node)->getMemOperand());
2770     Results.push_back(Swap.getValue(0));
2771     Results.push_back(Swap.getValue(1));
2772     break;
2773   }
2774   case ISD::ATOMIC_STORE: {
2775     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2776     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2777                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2778                                  Node->getOperand(0),
2779                                  Node->getOperand(1), Node->getOperand(2),
2780                                  cast<AtomicSDNode>(Node)->getMemOperand());
2781     Results.push_back(Swap.getValue(1));
2782     break;
2783   }
2784   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2785     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2786     // splits out the success value as a comparison. Expanding the resulting
2787     // ATOMIC_CMP_SWAP will produce a libcall.
2788     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2789     SDValue Res = DAG.getAtomicCmpSwap(
2790         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2791         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2792         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2793 
2794     SDValue ExtRes = Res;
2795     SDValue LHS = Res;
2796     SDValue RHS = Node->getOperand(1);
2797 
2798     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2799     EVT OuterType = Node->getValueType(0);
2800     switch (TLI.getExtendForAtomicOps()) {
2801     case ISD::SIGN_EXTEND:
2802       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2803                         DAG.getValueType(AtomicType));
2804       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2805                         Node->getOperand(2), DAG.getValueType(AtomicType));
2806       ExtRes = LHS;
2807       break;
2808     case ISD::ZERO_EXTEND:
2809       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2810                         DAG.getValueType(AtomicType));
2811       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2812       ExtRes = LHS;
2813       break;
2814     case ISD::ANY_EXTEND:
2815       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2816       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2817       break;
2818     default:
2819       llvm_unreachable("Invalid atomic op extension");
2820     }
2821 
2822     SDValue Success =
2823         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2824 
2825     Results.push_back(ExtRes.getValue(0));
2826     Results.push_back(Success);
2827     Results.push_back(Res.getValue(1));
2828     break;
2829   }
2830   case ISD::DYNAMIC_STACKALLOC:
2831     ExpandDYNAMIC_STACKALLOC(Node, Results);
2832     break;
2833   case ISD::MERGE_VALUES:
2834     for (unsigned i = 0; i < Node->getNumValues(); i++)
2835       Results.push_back(Node->getOperand(i));
2836     break;
2837   case ISD::UNDEF: {
2838     EVT VT = Node->getValueType(0);
2839     if (VT.isInteger())
2840       Results.push_back(DAG.getConstant(0, dl, VT));
2841     else {
2842       assert(VT.isFloatingPoint() && "Unknown value type!");
2843       Results.push_back(DAG.getConstantFP(0, dl, VT));
2844     }
2845     break;
2846   }
2847   case ISD::STRICT_FP_ROUND:
2848     // When strict mode is enforced we can't do expansion because it
2849     // does not honor the "strict" properties. Only libcall is allowed.
2850     if (TLI.isStrictFPEnabled())
2851       break;
2852     // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
2853     // since this operation is more efficient than stack operation.
2854     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2855                                        Node->getValueType(0))
2856         == TargetLowering::Legal)
2857       break;
2858     // We fall back to use stack operation when the FP_ROUND operation
2859     // isn't available.
2860     if ((Tmp1 = EmitStackConvert(Node->getOperand(1), Node->getValueType(0),
2861                                  Node->getValueType(0), dl,
2862                                  Node->getOperand(0)))) {
2863       ReplaceNode(Node, Tmp1.getNode());
2864       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_ROUND node\n");
2865       return true;
2866     }
2867     break;
2868   case ISD::FP_ROUND:
2869   case ISD::BITCAST:
2870     if ((Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
2871                                  Node->getValueType(0), dl)))
2872       Results.push_back(Tmp1);
2873     break;
2874   case ISD::STRICT_FP_EXTEND:
2875     // When strict mode is enforced we can't do expansion because it
2876     // does not honor the "strict" properties. Only libcall is allowed.
2877     if (TLI.isStrictFPEnabled())
2878       break;
2879     // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
2880     // since this operation is more efficient than stack operation.
2881     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2882                                        Node->getValueType(0))
2883         == TargetLowering::Legal)
2884       break;
2885     // We fall back to use stack operation when the FP_EXTEND operation
2886     // isn't available.
2887     if ((Tmp1 = EmitStackConvert(
2888              Node->getOperand(1), Node->getOperand(1).getValueType(),
2889              Node->getValueType(0), dl, Node->getOperand(0)))) {
2890       ReplaceNode(Node, Tmp1.getNode());
2891       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_EXTEND node\n");
2892       return true;
2893     }
2894     break;
2895   case ISD::FP_EXTEND:
2896     if ((Tmp1 = EmitStackConvert(Node->getOperand(0),
2897                                  Node->getOperand(0).getValueType(),
2898                                  Node->getValueType(0), dl)))
2899       Results.push_back(Tmp1);
2900     break;
2901   case ISD::SIGN_EXTEND_INREG: {
2902     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2903     EVT VT = Node->getValueType(0);
2904 
2905     // An in-register sign-extend of a boolean is a negation:
2906     // 'true' (1) sign-extended is -1.
2907     // 'false' (0) sign-extended is 0.
2908     // However, we must mask the high bits of the source operand because the
2909     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
2910 
2911     // TODO: Do this for vectors too?
2912     if (ExtraVT.getSizeInBits() == 1) {
2913       SDValue One = DAG.getConstant(1, dl, VT);
2914       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
2915       SDValue Zero = DAG.getConstant(0, dl, VT);
2916       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
2917       Results.push_back(Neg);
2918       break;
2919     }
2920 
2921     // NOTE: we could fall back on load/store here too for targets without
2922     // SRA.  However, it is doubtful that any exist.
2923     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2924     unsigned BitsDiff = VT.getScalarSizeInBits() -
2925                         ExtraVT.getScalarSizeInBits();
2926     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
2927     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
2928                        Node->getOperand(0), ShiftCst);
2929     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
2930     Results.push_back(Tmp1);
2931     break;
2932   }
2933   case ISD::UINT_TO_FP:
2934   case ISD::STRICT_UINT_TO_FP:
2935     if (TLI.expandUINT_TO_FP(Node, Tmp1, Tmp2, DAG)) {
2936       Results.push_back(Tmp1);
2937       if (Node->isStrictFPOpcode())
2938         Results.push_back(Tmp2);
2939       break;
2940     }
2941     LLVM_FALLTHROUGH;
2942   case ISD::SINT_TO_FP:
2943   case ISD::STRICT_SINT_TO_FP:
2944     if ((Tmp1 = ExpandLegalINT_TO_FP(Node, Tmp2))) {
2945       Results.push_back(Tmp1);
2946       if (Node->isStrictFPOpcode())
2947         Results.push_back(Tmp2);
2948     }
2949     break;
2950   case ISD::FP_TO_SINT:
2951     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
2952       Results.push_back(Tmp1);
2953     break;
2954   case ISD::STRICT_FP_TO_SINT:
2955     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG)) {
2956       ReplaceNode(Node, Tmp1.getNode());
2957       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_SINT node\n");
2958       return true;
2959     }
2960     break;
2961   case ISD::FP_TO_UINT:
2962     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG))
2963       Results.push_back(Tmp1);
2964     break;
2965   case ISD::STRICT_FP_TO_UINT:
2966     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG)) {
2967       // Relink the chain.
2968       DAG.ReplaceAllUsesOfValueWith(SDValue(Node,1), Tmp2);
2969       // Replace the new UINT result.
2970       ReplaceNodeWithValue(SDValue(Node, 0), Tmp1);
2971       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_UINT node\n");
2972       return true;
2973     }
2974     break;
2975   case ISD::FP_TO_SINT_SAT:
2976   case ISD::FP_TO_UINT_SAT:
2977     Results.push_back(TLI.expandFP_TO_INT_SAT(Node, DAG));
2978     break;
2979   case ISD::VAARG:
2980     Results.push_back(DAG.expandVAArg(Node));
2981     Results.push_back(Results[0].getValue(1));
2982     break;
2983   case ISD::VACOPY:
2984     Results.push_back(DAG.expandVACopy(Node));
2985     break;
2986   case ISD::EXTRACT_VECTOR_ELT:
2987     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
2988       // This must be an access of the only element.  Return it.
2989       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
2990                          Node->getOperand(0));
2991     else
2992       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
2993     Results.push_back(Tmp1);
2994     break;
2995   case ISD::EXTRACT_SUBVECTOR:
2996     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
2997     break;
2998   case ISD::INSERT_SUBVECTOR:
2999     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3000     break;
3001   case ISD::CONCAT_VECTORS:
3002     Results.push_back(ExpandVectorBuildThroughStack(Node));
3003     break;
3004   case ISD::SCALAR_TO_VECTOR:
3005     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3006     break;
3007   case ISD::INSERT_VECTOR_ELT:
3008     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3009                                               Node->getOperand(1),
3010                                               Node->getOperand(2), dl));
3011     break;
3012   case ISD::VECTOR_SHUFFLE: {
3013     SmallVector<int, 32> NewMask;
3014     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3015 
3016     EVT VT = Node->getValueType(0);
3017     EVT EltVT = VT.getVectorElementType();
3018     SDValue Op0 = Node->getOperand(0);
3019     SDValue Op1 = Node->getOperand(1);
3020     if (!TLI.isTypeLegal(EltVT)) {
3021       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3022 
3023       // BUILD_VECTOR operands are allowed to be wider than the element type.
3024       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3025       // it.
3026       if (NewEltVT.bitsLT(EltVT)) {
3027         // Convert shuffle node.
3028         // If original node was v4i64 and the new EltVT is i32,
3029         // cast operands to v8i32 and re-build the mask.
3030 
3031         // Calculate new VT, the size of the new VT should be equal to original.
3032         EVT NewVT =
3033             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3034                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3035         assert(NewVT.bitsEq(VT));
3036 
3037         // cast operands to new VT
3038         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3039         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3040 
3041         // Convert the shuffle mask
3042         unsigned int factor =
3043                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3044 
3045         // EltVT gets smaller
3046         assert(factor > 0);
3047 
3048         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3049           if (Mask[i] < 0) {
3050             for (unsigned fi = 0; fi < factor; ++fi)
3051               NewMask.push_back(Mask[i]);
3052           }
3053           else {
3054             for (unsigned fi = 0; fi < factor; ++fi)
3055               NewMask.push_back(Mask[i]*factor+fi);
3056           }
3057         }
3058         Mask = NewMask;
3059         VT = NewVT;
3060       }
3061       EltVT = NewEltVT;
3062     }
3063     unsigned NumElems = VT.getVectorNumElements();
3064     SmallVector<SDValue, 16> Ops;
3065     for (unsigned i = 0; i != NumElems; ++i) {
3066       if (Mask[i] < 0) {
3067         Ops.push_back(DAG.getUNDEF(EltVT));
3068         continue;
3069       }
3070       unsigned Idx = Mask[i];
3071       if (Idx < NumElems)
3072         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3073                                   DAG.getVectorIdxConstant(Idx, dl)));
3074       else
3075         Ops.push_back(
3076             DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3077                         DAG.getVectorIdxConstant(Idx - NumElems, dl)));
3078     }
3079 
3080     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3081     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3082     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3083     Results.push_back(Tmp1);
3084     break;
3085   }
3086   case ISD::VECTOR_SPLICE: {
3087     Results.push_back(TLI.expandVectorSplice(Node, DAG));
3088     break;
3089   }
3090   case ISD::EXTRACT_ELEMENT: {
3091     EVT OpTy = Node->getOperand(0).getValueType();
3092     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3093       // 1 -> Hi
3094       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3095                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3096                                          TLI.getShiftAmountTy(
3097                                              Node->getOperand(0).getValueType(),
3098                                              DAG.getDataLayout())));
3099       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3100     } else {
3101       // 0 -> Lo
3102       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3103                          Node->getOperand(0));
3104     }
3105     Results.push_back(Tmp1);
3106     break;
3107   }
3108   case ISD::STACKSAVE:
3109     // Expand to CopyFromReg if the target set
3110     // StackPointerRegisterToSaveRestore.
3111     if (Register SP = TLI.getStackPointerRegisterToSaveRestore()) {
3112       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3113                                            Node->getValueType(0)));
3114       Results.push_back(Results[0].getValue(1));
3115     } else {
3116       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3117       Results.push_back(Node->getOperand(0));
3118     }
3119     break;
3120   case ISD::STACKRESTORE:
3121     // Expand to CopyToReg if the target set
3122     // StackPointerRegisterToSaveRestore.
3123     if (Register SP = TLI.getStackPointerRegisterToSaveRestore()) {
3124       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3125                                          Node->getOperand(1)));
3126     } else {
3127       Results.push_back(Node->getOperand(0));
3128     }
3129     break;
3130   case ISD::GET_DYNAMIC_AREA_OFFSET:
3131     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3132     Results.push_back(Results[0].getValue(0));
3133     break;
3134   case ISD::FCOPYSIGN:
3135     Results.push_back(ExpandFCOPYSIGN(Node));
3136     break;
3137   case ISD::FNEG:
3138     Results.push_back(ExpandFNEG(Node));
3139     break;
3140   case ISD::FABS:
3141     Results.push_back(ExpandFABS(Node));
3142     break;
3143   case ISD::SMIN:
3144   case ISD::SMAX:
3145   case ISD::UMIN:
3146   case ISD::UMAX: {
3147     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3148     ISD::CondCode Pred;
3149     switch (Node->getOpcode()) {
3150     default: llvm_unreachable("How did we get here?");
3151     case ISD::SMAX: Pred = ISD::SETGT; break;
3152     case ISD::SMIN: Pred = ISD::SETLT; break;
3153     case ISD::UMAX: Pred = ISD::SETUGT; break;
3154     case ISD::UMIN: Pred = ISD::SETULT; break;
3155     }
3156     Tmp1 = Node->getOperand(0);
3157     Tmp2 = Node->getOperand(1);
3158     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3159     Results.push_back(Tmp1);
3160     break;
3161   }
3162   case ISD::FMINNUM:
3163   case ISD::FMAXNUM: {
3164     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3165       Results.push_back(Expanded);
3166     break;
3167   }
3168   case ISD::FSIN:
3169   case ISD::FCOS: {
3170     EVT VT = Node->getValueType(0);
3171     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3172     // fcos which share the same operand and both are used.
3173     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3174          isSinCosLibcallAvailable(Node, TLI))
3175         && useSinCos(Node)) {
3176       SDVTList VTs = DAG.getVTList(VT, VT);
3177       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3178       if (Node->getOpcode() == ISD::FCOS)
3179         Tmp1 = Tmp1.getValue(1);
3180       Results.push_back(Tmp1);
3181     }
3182     break;
3183   }
3184   case ISD::FMAD:
3185     llvm_unreachable("Illegal fmad should never be formed");
3186 
3187   case ISD::FP16_TO_FP:
3188     if (Node->getValueType(0) != MVT::f32) {
3189       // We can extend to types bigger than f32 in two steps without changing
3190       // the result. Since "f16 -> f32" is much more commonly available, give
3191       // CodeGen the option of emitting that before resorting to a libcall.
3192       SDValue Res =
3193           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3194       Results.push_back(
3195           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3196     }
3197     break;
3198   case ISD::STRICT_FP16_TO_FP:
3199     if (Node->getValueType(0) != MVT::f32) {
3200       // We can extend to types bigger than f32 in two steps without changing
3201       // the result. Since "f16 -> f32" is much more commonly available, give
3202       // CodeGen the option of emitting that before resorting to a libcall.
3203       SDValue Res =
3204           DAG.getNode(ISD::STRICT_FP16_TO_FP, dl, {MVT::f32, MVT::Other},
3205                       {Node->getOperand(0), Node->getOperand(1)});
3206       Res = DAG.getNode(ISD::STRICT_FP_EXTEND, dl,
3207                         {Node->getValueType(0), MVT::Other},
3208                         {Res.getValue(1), Res});
3209       Results.push_back(Res);
3210       Results.push_back(Res.getValue(1));
3211     }
3212     break;
3213   case ISD::FP_TO_FP16:
3214     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3215     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3216       SDValue Op = Node->getOperand(0);
3217       MVT SVT = Op.getSimpleValueType();
3218       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3219           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3220         // Under fastmath, we can expand this node into a fround followed by
3221         // a float-half conversion.
3222         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3223                                        DAG.getIntPtrConstant(0, dl));
3224         Results.push_back(
3225             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3226       }
3227     }
3228     break;
3229   case ISD::ConstantFP: {
3230     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3231     // Check to see if this FP immediate is already legal.
3232     // If this is a legal constant, turn it into a TargetConstantFP node.
3233     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0),
3234                           DAG.shouldOptForSize()))
3235       Results.push_back(ExpandConstantFP(CFP, true));
3236     break;
3237   }
3238   case ISD::Constant: {
3239     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3240     Results.push_back(ExpandConstant(CP));
3241     break;
3242   }
3243   case ISD::FSUB: {
3244     EVT VT = Node->getValueType(0);
3245     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3246         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3247       const SDNodeFlags Flags = Node->getFlags();
3248       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3249       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3250       Results.push_back(Tmp1);
3251     }
3252     break;
3253   }
3254   case ISD::SUB: {
3255     EVT VT = Node->getValueType(0);
3256     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3257            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3258            "Don't know how to expand this subtraction!");
3259     Tmp1 = DAG.getNOT(dl, Node->getOperand(1), VT);
3260     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3261     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3262     break;
3263   }
3264   case ISD::UREM:
3265   case ISD::SREM:
3266     if (TLI.expandREM(Node, Tmp1, DAG))
3267       Results.push_back(Tmp1);
3268     break;
3269   case ISD::UDIV:
3270   case ISD::SDIV: {
3271     bool isSigned = Node->getOpcode() == ISD::SDIV;
3272     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3273     EVT VT = Node->getValueType(0);
3274     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3275       SDVTList VTs = DAG.getVTList(VT, VT);
3276       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3277                          Node->getOperand(1));
3278       Results.push_back(Tmp1);
3279     }
3280     break;
3281   }
3282   case ISD::MULHU:
3283   case ISD::MULHS: {
3284     unsigned ExpandOpcode =
3285         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3286     EVT VT = Node->getValueType(0);
3287     SDVTList VTs = DAG.getVTList(VT, VT);
3288 
3289     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3290                        Node->getOperand(1));
3291     Results.push_back(Tmp1.getValue(1));
3292     break;
3293   }
3294   case ISD::UMUL_LOHI:
3295   case ISD::SMUL_LOHI: {
3296     SDValue LHS = Node->getOperand(0);
3297     SDValue RHS = Node->getOperand(1);
3298     MVT VT = LHS.getSimpleValueType();
3299     unsigned MULHOpcode =
3300         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3301 
3302     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3303       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3304       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3305       break;
3306     }
3307 
3308     SmallVector<SDValue, 4> Halves;
3309     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3310     assert(TLI.isTypeLegal(HalfType));
3311     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, dl, LHS, RHS, Halves,
3312                            HalfType, DAG,
3313                            TargetLowering::MulExpansionKind::Always)) {
3314       for (unsigned i = 0; i < 2; ++i) {
3315         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3316         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3317         SDValue Shift = DAG.getConstant(
3318             HalfType.getScalarSizeInBits(), dl,
3319             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3320         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3321         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3322       }
3323       break;
3324     }
3325     break;
3326   }
3327   case ISD::MUL: {
3328     EVT VT = Node->getValueType(0);
3329     SDVTList VTs = DAG.getVTList(VT, VT);
3330     // See if multiply or divide can be lowered using two-result operations.
3331     // We just need the low half of the multiply; try both the signed
3332     // and unsigned forms. If the target supports both SMUL_LOHI and
3333     // UMUL_LOHI, form a preference by checking which forms of plain
3334     // MULH it supports.
3335     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3336     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3337     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3338     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3339     unsigned OpToUse = 0;
3340     if (HasSMUL_LOHI && !HasMULHS) {
3341       OpToUse = ISD::SMUL_LOHI;
3342     } else if (HasUMUL_LOHI && !HasMULHU) {
3343       OpToUse = ISD::UMUL_LOHI;
3344     } else if (HasSMUL_LOHI) {
3345       OpToUse = ISD::SMUL_LOHI;
3346     } else if (HasUMUL_LOHI) {
3347       OpToUse = ISD::UMUL_LOHI;
3348     }
3349     if (OpToUse) {
3350       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3351                                     Node->getOperand(1)));
3352       break;
3353     }
3354 
3355     SDValue Lo, Hi;
3356     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3357     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3358         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3359         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3360         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3361         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3362                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3363       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3364       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3365       SDValue Shift =
3366           DAG.getConstant(HalfType.getSizeInBits(), dl,
3367                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3368       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3369       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3370     }
3371     break;
3372   }
3373   case ISD::FSHL:
3374   case ISD::FSHR:
3375     if (SDValue Expanded = TLI.expandFunnelShift(Node, DAG))
3376       Results.push_back(Expanded);
3377     break;
3378   case ISD::ROTL:
3379   case ISD::ROTR:
3380     if (SDValue Expanded = TLI.expandROT(Node, true /*AllowVectorOps*/, DAG))
3381       Results.push_back(Expanded);
3382     break;
3383   case ISD::SADDSAT:
3384   case ISD::UADDSAT:
3385   case ISD::SSUBSAT:
3386   case ISD::USUBSAT:
3387     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3388     break;
3389   case ISD::SSHLSAT:
3390   case ISD::USHLSAT:
3391     Results.push_back(TLI.expandShlSat(Node, DAG));
3392     break;
3393   case ISD::SMULFIX:
3394   case ISD::SMULFIXSAT:
3395   case ISD::UMULFIX:
3396   case ISD::UMULFIXSAT:
3397     Results.push_back(TLI.expandFixedPointMul(Node, DAG));
3398     break;
3399   case ISD::SDIVFIX:
3400   case ISD::SDIVFIXSAT:
3401   case ISD::UDIVFIX:
3402   case ISD::UDIVFIXSAT:
3403     if (SDValue V = TLI.expandFixedPointDiv(Node->getOpcode(), SDLoc(Node),
3404                                             Node->getOperand(0),
3405                                             Node->getOperand(1),
3406                                             Node->getConstantOperandVal(2),
3407                                             DAG)) {
3408       Results.push_back(V);
3409       break;
3410     }
3411     // FIXME: We might want to retry here with a wider type if we fail, if that
3412     // type is legal.
3413     // FIXME: Technically, so long as we only have sdivfixes where BW+Scale is
3414     // <= 128 (which is the case for all of the default Embedded-C types),
3415     // we will only get here with types and scales that we could always expand
3416     // if we were allowed to generate libcalls to division functions of illegal
3417     // type. But we cannot do that.
3418     llvm_unreachable("Cannot expand DIVFIX!");
3419   case ISD::ADDCARRY:
3420   case ISD::SUBCARRY: {
3421     SDValue LHS = Node->getOperand(0);
3422     SDValue RHS = Node->getOperand(1);
3423     SDValue Carry = Node->getOperand(2);
3424 
3425     bool IsAdd = Node->getOpcode() == ISD::ADDCARRY;
3426 
3427     // Initial add of the 2 operands.
3428     unsigned Op = IsAdd ? ISD::ADD : ISD::SUB;
3429     EVT VT = LHS.getValueType();
3430     SDValue Sum = DAG.getNode(Op, dl, VT, LHS, RHS);
3431 
3432     // Initial check for overflow.
3433     EVT CarryType = Node->getValueType(1);
3434     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3435     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3436     SDValue Overflow = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3437 
3438     // Add of the sum and the carry.
3439     SDValue One = DAG.getConstant(1, dl, VT);
3440     SDValue CarryExt =
3441         DAG.getNode(ISD::AND, dl, VT, DAG.getZExtOrTrunc(Carry, dl, VT), One);
3442     SDValue Sum2 = DAG.getNode(Op, dl, VT, Sum, CarryExt);
3443 
3444     // Second check for overflow. If we are adding, we can only overflow if the
3445     // initial sum is all 1s ang the carry is set, resulting in a new sum of 0.
3446     // If we are subtracting, we can only overflow if the initial sum is 0 and
3447     // the carry is set, resulting in a new sum of all 1s.
3448     SDValue Zero = DAG.getConstant(0, dl, VT);
3449     SDValue Overflow2 =
3450         IsAdd ? DAG.getSetCC(dl, SetCCType, Sum2, Zero, ISD::SETEQ)
3451               : DAG.getSetCC(dl, SetCCType, Sum, Zero, ISD::SETEQ);
3452     Overflow2 = DAG.getNode(ISD::AND, dl, SetCCType, Overflow2,
3453                             DAG.getZExtOrTrunc(Carry, dl, SetCCType));
3454 
3455     SDValue ResultCarry =
3456         DAG.getNode(ISD::OR, dl, SetCCType, Overflow, Overflow2);
3457 
3458     Results.push_back(Sum2);
3459     Results.push_back(DAG.getBoolExtOrTrunc(ResultCarry, dl, CarryType, VT));
3460     break;
3461   }
3462   case ISD::SADDO:
3463   case ISD::SSUBO: {
3464     SDValue Result, Overflow;
3465     TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
3466     Results.push_back(Result);
3467     Results.push_back(Overflow);
3468     break;
3469   }
3470   case ISD::UADDO:
3471   case ISD::USUBO: {
3472     SDValue Result, Overflow;
3473     TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
3474     Results.push_back(Result);
3475     Results.push_back(Overflow);
3476     break;
3477   }
3478   case ISD::UMULO:
3479   case ISD::SMULO: {
3480     SDValue Result, Overflow;
3481     if (TLI.expandMULO(Node, Result, Overflow, DAG)) {
3482       Results.push_back(Result);
3483       Results.push_back(Overflow);
3484     }
3485     break;
3486   }
3487   case ISD::BUILD_PAIR: {
3488     EVT PairTy = Node->getValueType(0);
3489     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3490     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3491     Tmp2 = DAG.getNode(
3492         ISD::SHL, dl, PairTy, Tmp2,
3493         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3494                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3495     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3496     break;
3497   }
3498   case ISD::SELECT:
3499     Tmp1 = Node->getOperand(0);
3500     Tmp2 = Node->getOperand(1);
3501     Tmp3 = Node->getOperand(2);
3502     if (Tmp1.getOpcode() == ISD::SETCC) {
3503       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3504                              Tmp2, Tmp3,
3505                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3506     } else {
3507       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3508                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3509                              Tmp2, Tmp3, ISD::SETNE);
3510     }
3511     Tmp1->setFlags(Node->getFlags());
3512     Results.push_back(Tmp1);
3513     break;
3514   case ISD::BR_JT: {
3515     SDValue Chain = Node->getOperand(0);
3516     SDValue Table = Node->getOperand(1);
3517     SDValue Index = Node->getOperand(2);
3518 
3519     const DataLayout &TD = DAG.getDataLayout();
3520     EVT PTy = TLI.getPointerTy(TD);
3521 
3522     unsigned EntrySize =
3523       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3524 
3525     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3526     // This transformation needs to be done here since otherwise the MIPS
3527     // backend will end up emitting a three instruction multiply sequence
3528     // instead of a single shift and MSP430 will call a runtime function.
3529     if (llvm::isPowerOf2_32(EntrySize))
3530       Index = DAG.getNode(
3531           ISD::SHL, dl, Index.getValueType(), Index,
3532           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3533     else
3534       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3535                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3536     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3537                                Index, Table);
3538 
3539     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3540     SDValue LD = DAG.getExtLoad(
3541         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3542         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3543     Addr = LD;
3544     if (TLI.isJumpTableRelative()) {
3545       // For PIC, the sequence is:
3546       // BRIND(load(Jumptable + index) + RelocBase)
3547       // RelocBase can be JumpTable, GOT or some sort of global base.
3548       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3549                           TLI.getPICJumpTableRelocBase(Table, DAG));
3550     }
3551 
3552     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3553     Results.push_back(Tmp1);
3554     break;
3555   }
3556   case ISD::BRCOND:
3557     // Expand brcond's setcc into its constituent parts and create a BR_CC
3558     // Node.
3559     Tmp1 = Node->getOperand(0);
3560     Tmp2 = Node->getOperand(1);
3561     if (Tmp2.getOpcode() == ISD::SETCC &&
3562         TLI.isOperationLegalOrCustom(ISD::BR_CC,
3563                                      Tmp2.getOperand(0).getValueType())) {
3564       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1, Tmp2.getOperand(2),
3565                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3566                          Node->getOperand(2));
3567     } else {
3568       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3569       if (Tmp2.isUndef() ||
3570           (Tmp2.getOpcode() == ISD::AND &&
3571            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3572            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3573         Tmp3 = Tmp2;
3574       else
3575         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3576                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3577       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3578                          DAG.getCondCode(ISD::SETNE), Tmp3,
3579                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3580                          Node->getOperand(2));
3581     }
3582     Results.push_back(Tmp1);
3583     break;
3584   case ISD::SETCC:
3585   case ISD::STRICT_FSETCC:
3586   case ISD::STRICT_FSETCCS: {
3587     bool IsStrict = Node->getOpcode() != ISD::SETCC;
3588     bool IsSignaling = Node->getOpcode() == ISD::STRICT_FSETCCS;
3589     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
3590     unsigned Offset = IsStrict ? 1 : 0;
3591     Tmp1 = Node->getOperand(0 + Offset);
3592     Tmp2 = Node->getOperand(1 + Offset);
3593     Tmp3 = Node->getOperand(2 + Offset);
3594     bool Legalized =
3595         TLI.LegalizeSetCCCondCode(DAG, Node->getValueType(0), Tmp1, Tmp2, Tmp3,
3596                                   NeedInvert, dl, Chain, IsSignaling);
3597 
3598     if (Legalized) {
3599       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3600       // condition code, create a new SETCC node.
3601       if (Tmp3.getNode()) {
3602         if (IsStrict) {
3603           Tmp1 = DAG.getNode(Node->getOpcode(), dl, Node->getVTList(),
3604                              {Chain, Tmp1, Tmp2, Tmp3}, Node->getFlags());
3605           Chain = Tmp1.getValue(1);
3606         } else {
3607           Tmp1 = DAG.getNode(Node->getOpcode(), dl, Node->getValueType(0), Tmp1,
3608                              Tmp2, Tmp3, Node->getFlags());
3609         }
3610       }
3611 
3612       // If we expanded the SETCC by inverting the condition code, then wrap
3613       // the existing SETCC in a NOT to restore the intended condition.
3614       if (NeedInvert)
3615         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3616 
3617       Results.push_back(Tmp1);
3618       if (IsStrict)
3619         Results.push_back(Chain);
3620 
3621       break;
3622     }
3623 
3624     // FIXME: It seems Legalized is false iff CCCode is Legal. I don't
3625     // understand if this code is useful for strict nodes.
3626     assert(!IsStrict && "Don't know how to expand for strict nodes.");
3627 
3628     // Otherwise, SETCC for the given comparison type must be completely
3629     // illegal; expand it into a SELECT_CC.
3630     EVT VT = Node->getValueType(0);
3631     int TrueValue;
3632     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3633     case TargetLowering::ZeroOrOneBooleanContent:
3634     case TargetLowering::UndefinedBooleanContent:
3635       TrueValue = 1;
3636       break;
3637     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3638       TrueValue = -1;
3639       break;
3640     }
3641     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3642                        DAG.getConstant(TrueValue, dl, VT),
3643                        DAG.getConstant(0, dl, VT),
3644                        Tmp3);
3645     Tmp1->setFlags(Node->getFlags());
3646     Results.push_back(Tmp1);
3647     break;
3648   }
3649   case ISD::SELECT_CC: {
3650     // TODO: need to add STRICT_SELECT_CC and STRICT_SELECT_CCS
3651     Tmp1 = Node->getOperand(0);   // LHS
3652     Tmp2 = Node->getOperand(1);   // RHS
3653     Tmp3 = Node->getOperand(2);   // True
3654     Tmp4 = Node->getOperand(3);   // False
3655     EVT VT = Node->getValueType(0);
3656     SDValue Chain;
3657     SDValue CC = Node->getOperand(4);
3658     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3659 
3660     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3661       // If the condition code is legal, then we need to expand this
3662       // node using SETCC and SELECT.
3663       EVT CmpVT = Tmp1.getValueType();
3664       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3665              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3666              "expanded.");
3667       EVT CCVT = getSetCCResultType(CmpVT);
3668       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC, Node->getFlags());
3669       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3670       break;
3671     }
3672 
3673     // SELECT_CC is legal, so the condition code must not be.
3674     bool Legalized = false;
3675     // Try to legalize by inverting the condition.  This is for targets that
3676     // might support an ordered version of a condition, but not the unordered
3677     // version (or vice versa).
3678     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp, Tmp1.getValueType());
3679     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3680       // Use the new condition code and swap true and false
3681       Legalized = true;
3682       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3683       Tmp1->setFlags(Node->getFlags());
3684     } else {
3685       // If The inverse is not legal, then try to swap the arguments using
3686       // the inverse condition code.
3687       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3688       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3689         // The swapped inverse condition is legal, so swap true and false,
3690         // lhs and rhs.
3691         Legalized = true;
3692         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3693         Tmp1->setFlags(Node->getFlags());
3694       }
3695     }
3696 
3697     if (!Legalized) {
3698       Legalized = TLI.LegalizeSetCCCondCode(
3699           DAG, getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC,
3700           NeedInvert, dl, Chain);
3701 
3702       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3703 
3704       // If we expanded the SETCC by inverting the condition code, then swap
3705       // the True/False operands to match.
3706       if (NeedInvert)
3707         std::swap(Tmp3, Tmp4);
3708 
3709       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3710       // condition code, create a new SELECT_CC node.
3711       if (CC.getNode()) {
3712         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3713                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3714       } else {
3715         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3716         CC = DAG.getCondCode(ISD::SETNE);
3717         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3718                            Tmp2, Tmp3, Tmp4, CC);
3719       }
3720       Tmp1->setFlags(Node->getFlags());
3721     }
3722     Results.push_back(Tmp1);
3723     break;
3724   }
3725   case ISD::BR_CC: {
3726     // TODO: need to add STRICT_BR_CC and STRICT_BR_CCS
3727     SDValue Chain;
3728     Tmp1 = Node->getOperand(0);              // Chain
3729     Tmp2 = Node->getOperand(2);              // LHS
3730     Tmp3 = Node->getOperand(3);              // RHS
3731     Tmp4 = Node->getOperand(1);              // CC
3732 
3733     bool Legalized =
3734         TLI.LegalizeSetCCCondCode(DAG, getSetCCResultType(Tmp2.getValueType()),
3735                                   Tmp2, Tmp3, Tmp4, NeedInvert, dl, Chain);
3736     (void)Legalized;
3737     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3738 
3739     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3740     // node.
3741     if (Tmp4.getNode()) {
3742       assert(!NeedInvert && "Don't know how to invert BR_CC!");
3743 
3744       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3745                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3746     } else {
3747       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3748       Tmp4 = DAG.getCondCode(NeedInvert ? ISD::SETEQ : ISD::SETNE);
3749       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3750                          Tmp2, Tmp3, Node->getOperand(4));
3751     }
3752     Results.push_back(Tmp1);
3753     break;
3754   }
3755   case ISD::BUILD_VECTOR:
3756     Results.push_back(ExpandBUILD_VECTOR(Node));
3757     break;
3758   case ISD::SPLAT_VECTOR:
3759     Results.push_back(ExpandSPLAT_VECTOR(Node));
3760     break;
3761   case ISD::SRA:
3762   case ISD::SRL:
3763   case ISD::SHL: {
3764     // Scalarize vector SRA/SRL/SHL.
3765     EVT VT = Node->getValueType(0);
3766     assert(VT.isVector() && "Unable to legalize non-vector shift");
3767     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3768     unsigned NumElem = VT.getVectorNumElements();
3769 
3770     SmallVector<SDValue, 8> Scalars;
3771     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3772       SDValue Ex =
3773           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3774                       Node->getOperand(0), DAG.getVectorIdxConstant(Idx, dl));
3775       SDValue Sh =
3776           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3777                       Node->getOperand(1), DAG.getVectorIdxConstant(Idx, dl));
3778       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3779                                     VT.getScalarType(), Ex, Sh));
3780     }
3781 
3782     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3783     Results.push_back(Result);
3784     break;
3785   }
3786   case ISD::VECREDUCE_FADD:
3787   case ISD::VECREDUCE_FMUL:
3788   case ISD::VECREDUCE_ADD:
3789   case ISD::VECREDUCE_MUL:
3790   case ISD::VECREDUCE_AND:
3791   case ISD::VECREDUCE_OR:
3792   case ISD::VECREDUCE_XOR:
3793   case ISD::VECREDUCE_SMAX:
3794   case ISD::VECREDUCE_SMIN:
3795   case ISD::VECREDUCE_UMAX:
3796   case ISD::VECREDUCE_UMIN:
3797   case ISD::VECREDUCE_FMAX:
3798   case ISD::VECREDUCE_FMIN:
3799     Results.push_back(TLI.expandVecReduce(Node, DAG));
3800     break;
3801   case ISD::GLOBAL_OFFSET_TABLE:
3802   case ISD::GlobalAddress:
3803   case ISD::GlobalTLSAddress:
3804   case ISD::ExternalSymbol:
3805   case ISD::ConstantPool:
3806   case ISD::JumpTable:
3807   case ISD::INTRINSIC_W_CHAIN:
3808   case ISD::INTRINSIC_WO_CHAIN:
3809   case ISD::INTRINSIC_VOID:
3810     // FIXME: Custom lowering for these operations shouldn't return null!
3811     // Return true so that we don't call ConvertNodeToLibcall which also won't
3812     // do anything.
3813     return true;
3814   }
3815 
3816   if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
3817     // FIXME: We were asked to expand a strict floating-point operation,
3818     // but there is currently no expansion implemented that would preserve
3819     // the "strict" properties.  For now, we just fall back to the non-strict
3820     // version if that is legal on the target.  The actual mutation of the
3821     // operation will happen in SelectionDAGISel::DoInstructionSelection.
3822     switch (Node->getOpcode()) {
3823     default:
3824       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3825                                          Node->getValueType(0))
3826           == TargetLowering::Legal)
3827         return true;
3828       break;
3829     case ISD::STRICT_FSUB: {
3830       if (TLI.getStrictFPOperationAction(
3831               ISD::STRICT_FSUB, Node->getValueType(0)) == TargetLowering::Legal)
3832         return true;
3833       if (TLI.getStrictFPOperationAction(
3834               ISD::STRICT_FADD, Node->getValueType(0)) != TargetLowering::Legal)
3835         break;
3836 
3837       EVT VT = Node->getValueType(0);
3838       const SDNodeFlags Flags = Node->getFlags();
3839       SDValue Neg = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(2), Flags);
3840       SDValue Fadd = DAG.getNode(ISD::STRICT_FADD, dl, Node->getVTList(),
3841                                  {Node->getOperand(0), Node->getOperand(1), Neg},
3842                          Flags);
3843 
3844       Results.push_back(Fadd);
3845       Results.push_back(Fadd.getValue(1));
3846       break;
3847     }
3848     case ISD::STRICT_SINT_TO_FP:
3849     case ISD::STRICT_UINT_TO_FP:
3850     case ISD::STRICT_LRINT:
3851     case ISD::STRICT_LLRINT:
3852     case ISD::STRICT_LROUND:
3853     case ISD::STRICT_LLROUND:
3854       // These are registered by the operand type instead of the value
3855       // type. Reflect that here.
3856       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3857                                          Node->getOperand(1).getValueType())
3858           == TargetLowering::Legal)
3859         return true;
3860       break;
3861     }
3862   }
3863 
3864   // Replace the original node with the legalized result.
3865   if (Results.empty()) {
3866     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3867     return false;
3868   }
3869 
3870   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3871   ReplaceNode(Node, Results.data());
3872   return true;
3873 }
3874 
3875 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3876   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3877   SmallVector<SDValue, 8> Results;
3878   SDLoc dl(Node);
3879   // FIXME: Check flags on the node to see if we can use a finite call.
3880   unsigned Opc = Node->getOpcode();
3881   switch (Opc) {
3882   case ISD::ATOMIC_FENCE: {
3883     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3884     // FIXME: handle "fence singlethread" more efficiently.
3885     TargetLowering::ArgListTy Args;
3886 
3887     TargetLowering::CallLoweringInfo CLI(DAG);
3888     CLI.setDebugLoc(dl)
3889         .setChain(Node->getOperand(0))
3890         .setLibCallee(
3891             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3892             DAG.getExternalSymbol("__sync_synchronize",
3893                                   TLI.getPointerTy(DAG.getDataLayout())),
3894             std::move(Args));
3895 
3896     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3897 
3898     Results.push_back(CallResult.second);
3899     break;
3900   }
3901   // By default, atomic intrinsics are marked Legal and lowered. Targets
3902   // which don't support them directly, however, may want libcalls, in which
3903   // case they mark them Expand, and we get here.
3904   case ISD::ATOMIC_SWAP:
3905   case ISD::ATOMIC_LOAD_ADD:
3906   case ISD::ATOMIC_LOAD_SUB:
3907   case ISD::ATOMIC_LOAD_AND:
3908   case ISD::ATOMIC_LOAD_CLR:
3909   case ISD::ATOMIC_LOAD_OR:
3910   case ISD::ATOMIC_LOAD_XOR:
3911   case ISD::ATOMIC_LOAD_NAND:
3912   case ISD::ATOMIC_LOAD_MIN:
3913   case ISD::ATOMIC_LOAD_MAX:
3914   case ISD::ATOMIC_LOAD_UMIN:
3915   case ISD::ATOMIC_LOAD_UMAX:
3916   case ISD::ATOMIC_CMP_SWAP: {
3917     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3918     AtomicOrdering Order = cast<AtomicSDNode>(Node)->getMergedOrdering();
3919     RTLIB::Libcall LC = RTLIB::getOUTLINE_ATOMIC(Opc, Order, VT);
3920     EVT RetVT = Node->getValueType(0);
3921     TargetLowering::MakeLibCallOptions CallOptions;
3922     SmallVector<SDValue, 4> Ops;
3923     if (TLI.getLibcallName(LC)) {
3924       // If outline atomic available, prepare its arguments and expand.
3925       Ops.append(Node->op_begin() + 2, Node->op_end());
3926       Ops.push_back(Node->getOperand(1));
3927 
3928     } else {
3929       LC = RTLIB::getSYNC(Opc, VT);
3930       assert(LC != RTLIB::UNKNOWN_LIBCALL &&
3931              "Unexpected atomic op or value type!");
3932       // Arguments for expansion to sync libcall
3933       Ops.append(Node->op_begin() + 1, Node->op_end());
3934     }
3935     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
3936                                                       Ops, CallOptions,
3937                                                       SDLoc(Node),
3938                                                       Node->getOperand(0));
3939     Results.push_back(Tmp.first);
3940     Results.push_back(Tmp.second);
3941     break;
3942   }
3943   case ISD::TRAP: {
3944     // If this operation is not supported, lower it to 'abort()' call
3945     TargetLowering::ArgListTy Args;
3946     TargetLowering::CallLoweringInfo CLI(DAG);
3947     CLI.setDebugLoc(dl)
3948         .setChain(Node->getOperand(0))
3949         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3950                       DAG.getExternalSymbol(
3951                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
3952                       std::move(Args));
3953     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3954 
3955     Results.push_back(CallResult.second);
3956     break;
3957   }
3958   case ISD::FMINNUM:
3959   case ISD::STRICT_FMINNUM:
3960     ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
3961                     RTLIB::FMIN_F80, RTLIB::FMIN_F128,
3962                     RTLIB::FMIN_PPCF128, Results);
3963     break;
3964   case ISD::FMAXNUM:
3965   case ISD::STRICT_FMAXNUM:
3966     ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
3967                     RTLIB::FMAX_F80, RTLIB::FMAX_F128,
3968                     RTLIB::FMAX_PPCF128, Results);
3969     break;
3970   case ISD::FSQRT:
3971   case ISD::STRICT_FSQRT:
3972     ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
3973                     RTLIB::SQRT_F80, RTLIB::SQRT_F128,
3974                     RTLIB::SQRT_PPCF128, Results);
3975     break;
3976   case ISD::FCBRT:
3977     ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
3978                     RTLIB::CBRT_F80, RTLIB::CBRT_F128,
3979                     RTLIB::CBRT_PPCF128, Results);
3980     break;
3981   case ISD::FSIN:
3982   case ISD::STRICT_FSIN:
3983     ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
3984                     RTLIB::SIN_F80, RTLIB::SIN_F128,
3985                     RTLIB::SIN_PPCF128, Results);
3986     break;
3987   case ISD::FCOS:
3988   case ISD::STRICT_FCOS:
3989     ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
3990                     RTLIB::COS_F80, RTLIB::COS_F128,
3991                     RTLIB::COS_PPCF128, Results);
3992     break;
3993   case ISD::FSINCOS:
3994     // Expand into sincos libcall.
3995     ExpandSinCosLibCall(Node, Results);
3996     break;
3997   case ISD::FLOG:
3998   case ISD::STRICT_FLOG:
3999     ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64, RTLIB::LOG_F80,
4000                     RTLIB::LOG_F128, RTLIB::LOG_PPCF128, Results);
4001     break;
4002   case ISD::FLOG2:
4003   case ISD::STRICT_FLOG2:
4004     ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64, RTLIB::LOG2_F80,
4005                     RTLIB::LOG2_F128, RTLIB::LOG2_PPCF128, Results);
4006     break;
4007   case ISD::FLOG10:
4008   case ISD::STRICT_FLOG10:
4009     ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64, RTLIB::LOG10_F80,
4010                     RTLIB::LOG10_F128, RTLIB::LOG10_PPCF128, Results);
4011     break;
4012   case ISD::FEXP:
4013   case ISD::STRICT_FEXP:
4014     ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64, RTLIB::EXP_F80,
4015                     RTLIB::EXP_F128, RTLIB::EXP_PPCF128, Results);
4016     break;
4017   case ISD::FEXP2:
4018   case ISD::STRICT_FEXP2:
4019     ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64, RTLIB::EXP2_F80,
4020                     RTLIB::EXP2_F128, RTLIB::EXP2_PPCF128, Results);
4021     break;
4022   case ISD::FTRUNC:
4023   case ISD::STRICT_FTRUNC:
4024     ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4025                     RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4026                     RTLIB::TRUNC_PPCF128, Results);
4027     break;
4028   case ISD::FFLOOR:
4029   case ISD::STRICT_FFLOOR:
4030     ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4031                     RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4032                     RTLIB::FLOOR_PPCF128, Results);
4033     break;
4034   case ISD::FCEIL:
4035   case ISD::STRICT_FCEIL:
4036     ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4037                     RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4038                     RTLIB::CEIL_PPCF128, Results);
4039     break;
4040   case ISD::FRINT:
4041   case ISD::STRICT_FRINT:
4042     ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4043                     RTLIB::RINT_F80, RTLIB::RINT_F128,
4044                     RTLIB::RINT_PPCF128, Results);
4045     break;
4046   case ISD::FNEARBYINT:
4047   case ISD::STRICT_FNEARBYINT:
4048     ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4049                     RTLIB::NEARBYINT_F64,
4050                     RTLIB::NEARBYINT_F80,
4051                     RTLIB::NEARBYINT_F128,
4052                     RTLIB::NEARBYINT_PPCF128, Results);
4053     break;
4054   case ISD::FROUND:
4055   case ISD::STRICT_FROUND:
4056     ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4057                     RTLIB::ROUND_F64,
4058                     RTLIB::ROUND_F80,
4059                     RTLIB::ROUND_F128,
4060                     RTLIB::ROUND_PPCF128, Results);
4061     break;
4062   case ISD::FROUNDEVEN:
4063   case ISD::STRICT_FROUNDEVEN:
4064     ExpandFPLibCall(Node, RTLIB::ROUNDEVEN_F32,
4065                     RTLIB::ROUNDEVEN_F64,
4066                     RTLIB::ROUNDEVEN_F80,
4067                     RTLIB::ROUNDEVEN_F128,
4068                     RTLIB::ROUNDEVEN_PPCF128, Results);
4069     break;
4070   case ISD::FPOWI:
4071   case ISD::STRICT_FPOWI: {
4072     RTLIB::Libcall LC = RTLIB::getPOWI(Node->getSimpleValueType(0));
4073     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected fpowi.");
4074     if (!TLI.getLibcallName(LC)) {
4075       // Some targets don't have a powi libcall; use pow instead.
4076       SDValue Exponent = DAG.getNode(ISD::SINT_TO_FP, SDLoc(Node),
4077                                      Node->getValueType(0),
4078                                      Node->getOperand(1));
4079       Results.push_back(DAG.getNode(ISD::FPOW, SDLoc(Node),
4080                                     Node->getValueType(0), Node->getOperand(0),
4081                                     Exponent));
4082       break;
4083     }
4084     unsigned Offset = Node->isStrictFPOpcode() ? 1 : 0;
4085     bool ExponentHasSizeOfInt =
4086         DAG.getLibInfo().getIntSize() ==
4087         Node->getOperand(1 + Offset).getValueType().getSizeInBits();
4088     if (!ExponentHasSizeOfInt) {
4089       // If the exponent does not match with sizeof(int) a libcall to
4090       // RTLIB::POWI would use the wrong type for the argument.
4091       DAG.getContext()->emitError("POWI exponent does not match sizeof(int)");
4092       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
4093       break;
4094     }
4095     ExpandFPLibCall(Node, LC, Results);
4096     break;
4097   }
4098   case ISD::FPOW:
4099   case ISD::STRICT_FPOW:
4100     ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64, RTLIB::POW_F80,
4101                     RTLIB::POW_F128, RTLIB::POW_PPCF128, Results);
4102     break;
4103   case ISD::LROUND:
4104   case ISD::STRICT_LROUND:
4105     ExpandArgFPLibCall(Node, RTLIB::LROUND_F32,
4106                        RTLIB::LROUND_F64, RTLIB::LROUND_F80,
4107                        RTLIB::LROUND_F128,
4108                        RTLIB::LROUND_PPCF128, Results);
4109     break;
4110   case ISD::LLROUND:
4111   case ISD::STRICT_LLROUND:
4112     ExpandArgFPLibCall(Node, RTLIB::LLROUND_F32,
4113                        RTLIB::LLROUND_F64, RTLIB::LLROUND_F80,
4114                        RTLIB::LLROUND_F128,
4115                        RTLIB::LLROUND_PPCF128, Results);
4116     break;
4117   case ISD::LRINT:
4118   case ISD::STRICT_LRINT:
4119     ExpandArgFPLibCall(Node, RTLIB::LRINT_F32,
4120                        RTLIB::LRINT_F64, RTLIB::LRINT_F80,
4121                        RTLIB::LRINT_F128,
4122                        RTLIB::LRINT_PPCF128, Results);
4123     break;
4124   case ISD::LLRINT:
4125   case ISD::STRICT_LLRINT:
4126     ExpandArgFPLibCall(Node, RTLIB::LLRINT_F32,
4127                        RTLIB::LLRINT_F64, RTLIB::LLRINT_F80,
4128                        RTLIB::LLRINT_F128,
4129                        RTLIB::LLRINT_PPCF128, Results);
4130     break;
4131   case ISD::FDIV:
4132   case ISD::STRICT_FDIV:
4133     ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4134                     RTLIB::DIV_F80, RTLIB::DIV_F128,
4135                     RTLIB::DIV_PPCF128, Results);
4136     break;
4137   case ISD::FREM:
4138   case ISD::STRICT_FREM:
4139     ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4140                     RTLIB::REM_F80, RTLIB::REM_F128,
4141                     RTLIB::REM_PPCF128, Results);
4142     break;
4143   case ISD::FMA:
4144   case ISD::STRICT_FMA:
4145     ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4146                     RTLIB::FMA_F80, RTLIB::FMA_F128,
4147                     RTLIB::FMA_PPCF128, Results);
4148     break;
4149   case ISD::FADD:
4150   case ISD::STRICT_FADD:
4151     ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4152                     RTLIB::ADD_F80, RTLIB::ADD_F128,
4153                     RTLIB::ADD_PPCF128, Results);
4154     break;
4155   case ISD::FMUL:
4156   case ISD::STRICT_FMUL:
4157     ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4158                     RTLIB::MUL_F80, RTLIB::MUL_F128,
4159                     RTLIB::MUL_PPCF128, Results);
4160     break;
4161   case ISD::FP16_TO_FP:
4162     if (Node->getValueType(0) == MVT::f32) {
4163       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4164     }
4165     break;
4166   case ISD::STRICT_FP16_TO_FP: {
4167     if (Node->getValueType(0) == MVT::f32) {
4168       TargetLowering::MakeLibCallOptions CallOptions;
4169       std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(
4170           DAG, RTLIB::FPEXT_F16_F32, MVT::f32, Node->getOperand(1), CallOptions,
4171           SDLoc(Node), Node->getOperand(0));
4172       Results.push_back(Tmp.first);
4173       Results.push_back(Tmp.second);
4174     }
4175     break;
4176   }
4177   case ISD::FP_TO_FP16: {
4178     RTLIB::Libcall LC =
4179         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4180     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4181     Results.push_back(ExpandLibCall(LC, Node, false));
4182     break;
4183   }
4184   case ISD::STRICT_SINT_TO_FP:
4185   case ISD::STRICT_UINT_TO_FP:
4186   case ISD::SINT_TO_FP:
4187   case ISD::UINT_TO_FP: {
4188     // TODO - Common the code with DAGTypeLegalizer::SoftenFloatRes_XINT_TO_FP
4189     bool IsStrict = Node->isStrictFPOpcode();
4190     bool Signed = Node->getOpcode() == ISD::SINT_TO_FP ||
4191                   Node->getOpcode() == ISD::STRICT_SINT_TO_FP;
4192     EVT SVT = Node->getOperand(IsStrict ? 1 : 0).getValueType();
4193     EVT RVT = Node->getValueType(0);
4194     EVT NVT = EVT();
4195     SDLoc dl(Node);
4196 
4197     // Even if the input is legal, no libcall may exactly match, eg. we don't
4198     // have i1 -> fp conversions. So, it needs to be promoted to a larger type,
4199     // eg: i13 -> fp. Then, look for an appropriate libcall.
4200     RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
4201     for (unsigned t = MVT::FIRST_INTEGER_VALUETYPE;
4202          t <= MVT::LAST_INTEGER_VALUETYPE && LC == RTLIB::UNKNOWN_LIBCALL;
4203          ++t) {
4204       NVT = (MVT::SimpleValueType)t;
4205       // The source needs to big enough to hold the operand.
4206       if (NVT.bitsGE(SVT))
4207         LC = Signed ? RTLIB::getSINTTOFP(NVT, RVT)
4208                     : RTLIB::getUINTTOFP(NVT, RVT);
4209     }
4210     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4211 
4212     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
4213     // Sign/zero extend the argument if the libcall takes a larger type.
4214     SDValue Op = DAG.getNode(Signed ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND, dl,
4215                              NVT, Node->getOperand(IsStrict ? 1 : 0));
4216     TargetLowering::MakeLibCallOptions CallOptions;
4217     CallOptions.setSExt(Signed);
4218     std::pair<SDValue, SDValue> Tmp =
4219         TLI.makeLibCall(DAG, LC, RVT, Op, CallOptions, dl, Chain);
4220     Results.push_back(Tmp.first);
4221     if (IsStrict)
4222       Results.push_back(Tmp.second);
4223     break;
4224   }
4225   case ISD::FP_TO_SINT:
4226   case ISD::FP_TO_UINT:
4227   case ISD::STRICT_FP_TO_SINT:
4228   case ISD::STRICT_FP_TO_UINT: {
4229     // TODO - Common the code with DAGTypeLegalizer::SoftenFloatOp_FP_TO_XINT.
4230     bool IsStrict = Node->isStrictFPOpcode();
4231     bool Signed = Node->getOpcode() == ISD::FP_TO_SINT ||
4232                   Node->getOpcode() == ISD::STRICT_FP_TO_SINT;
4233 
4234     SDValue Op = Node->getOperand(IsStrict ? 1 : 0);
4235     EVT SVT = Op.getValueType();
4236     EVT RVT = Node->getValueType(0);
4237     EVT NVT = EVT();
4238     SDLoc dl(Node);
4239 
4240     // Even if the result is legal, no libcall may exactly match, eg. we don't
4241     // have fp -> i1 conversions. So, it needs to be promoted to a larger type,
4242     // eg: fp -> i32. Then, look for an appropriate libcall.
4243     RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
4244     for (unsigned IntVT = MVT::FIRST_INTEGER_VALUETYPE;
4245          IntVT <= MVT::LAST_INTEGER_VALUETYPE && LC == RTLIB::UNKNOWN_LIBCALL;
4246          ++IntVT) {
4247       NVT = (MVT::SimpleValueType)IntVT;
4248       // The type needs to big enough to hold the result.
4249       if (NVT.bitsGE(RVT))
4250         LC = Signed ? RTLIB::getFPTOSINT(SVT, NVT)
4251                     : RTLIB::getFPTOUINT(SVT, NVT);
4252     }
4253     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4254 
4255     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
4256     TargetLowering::MakeLibCallOptions CallOptions;
4257     std::pair<SDValue, SDValue> Tmp =
4258         TLI.makeLibCall(DAG, LC, NVT, Op, CallOptions, dl, Chain);
4259 
4260     // Truncate the result if the libcall returns a larger type.
4261     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, RVT, Tmp.first));
4262     if (IsStrict)
4263       Results.push_back(Tmp.second);
4264     break;
4265   }
4266 
4267   case ISD::FP_ROUND:
4268   case ISD::STRICT_FP_ROUND: {
4269     // X = FP_ROUND(Y, TRUNC)
4270     // TRUNC is a flag, which is always an integer that is zero or one.
4271     // If TRUNC is 0, this is a normal rounding, if it is 1, this FP_ROUND
4272     // is known to not change the value of Y.
4273     // We can only expand it into libcall if the TRUNC is 0.
4274     bool IsStrict = Node->isStrictFPOpcode();
4275     SDValue Op = Node->getOperand(IsStrict ? 1 : 0);
4276     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
4277     EVT VT = Node->getValueType(0);
4278     assert(cast<ConstantSDNode>(Node->getOperand(IsStrict ? 2 : 1))->isZero() &&
4279            "Unable to expand as libcall if it is not normal rounding");
4280 
4281     RTLIB::Libcall LC = RTLIB::getFPROUND(Op.getValueType(), VT);
4282     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4283 
4284     TargetLowering::MakeLibCallOptions CallOptions;
4285     std::pair<SDValue, SDValue> Tmp =
4286         TLI.makeLibCall(DAG, LC, VT, Op, CallOptions, SDLoc(Node), Chain);
4287     Results.push_back(Tmp.first);
4288     if (IsStrict)
4289       Results.push_back(Tmp.second);
4290     break;
4291   }
4292   case ISD::FP_EXTEND: {
4293     Results.push_back(
4294         ExpandLibCall(RTLIB::getFPEXT(Node->getOperand(0).getValueType(),
4295                                       Node->getValueType(0)),
4296                       Node, false));
4297     break;
4298   }
4299   case ISD::STRICT_FP_EXTEND:
4300   case ISD::STRICT_FP_TO_FP16: {
4301     RTLIB::Libcall LC =
4302         Node->getOpcode() == ISD::STRICT_FP_TO_FP16
4303             ? RTLIB::getFPROUND(Node->getOperand(1).getValueType(), MVT::f16)
4304             : RTLIB::getFPEXT(Node->getOperand(1).getValueType(),
4305                               Node->getValueType(0));
4306     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4307 
4308     TargetLowering::MakeLibCallOptions CallOptions;
4309     std::pair<SDValue, SDValue> Tmp =
4310         TLI.makeLibCall(DAG, LC, Node->getValueType(0), Node->getOperand(1),
4311                         CallOptions, SDLoc(Node), Node->getOperand(0));
4312     Results.push_back(Tmp.first);
4313     Results.push_back(Tmp.second);
4314     break;
4315   }
4316   case ISD::FSUB:
4317   case ISD::STRICT_FSUB:
4318     ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4319                     RTLIB::SUB_F80, RTLIB::SUB_F128,
4320                     RTLIB::SUB_PPCF128, Results);
4321     break;
4322   case ISD::SREM:
4323     Results.push_back(ExpandIntLibCall(Node, true,
4324                                        RTLIB::SREM_I8,
4325                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4326                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4327     break;
4328   case ISD::UREM:
4329     Results.push_back(ExpandIntLibCall(Node, false,
4330                                        RTLIB::UREM_I8,
4331                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4332                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4333     break;
4334   case ISD::SDIV:
4335     Results.push_back(ExpandIntLibCall(Node, true,
4336                                        RTLIB::SDIV_I8,
4337                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4338                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4339     break;
4340   case ISD::UDIV:
4341     Results.push_back(ExpandIntLibCall(Node, false,
4342                                        RTLIB::UDIV_I8,
4343                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4344                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4345     break;
4346   case ISD::SDIVREM:
4347   case ISD::UDIVREM:
4348     // Expand into divrem libcall
4349     ExpandDivRemLibCall(Node, Results);
4350     break;
4351   case ISD::MUL:
4352     Results.push_back(ExpandIntLibCall(Node, false,
4353                                        RTLIB::MUL_I8,
4354                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4355                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4356     break;
4357   case ISD::CTLZ_ZERO_UNDEF:
4358     switch (Node->getSimpleValueType(0).SimpleTy) {
4359     default:
4360       llvm_unreachable("LibCall explicitly requested, but not available");
4361     case MVT::i32:
4362       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4363       break;
4364     case MVT::i64:
4365       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4366       break;
4367     case MVT::i128:
4368       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4369       break;
4370     }
4371     break;
4372   }
4373 
4374   // Replace the original node with the legalized result.
4375   if (!Results.empty()) {
4376     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4377     ReplaceNode(Node, Results.data());
4378   } else
4379     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4380 }
4381 
4382 // Determine the vector type to use in place of an original scalar element when
4383 // promoting equally sized vectors.
4384 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4385                                         MVT EltVT, MVT NewEltVT) {
4386   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4387   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4388   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4389   return MidVT;
4390 }
4391 
4392 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4393   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4394   SmallVector<SDValue, 8> Results;
4395   MVT OVT = Node->getSimpleValueType(0);
4396   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4397       Node->getOpcode() == ISD::SINT_TO_FP ||
4398       Node->getOpcode() == ISD::SETCC ||
4399       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4400       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4401     OVT = Node->getOperand(0).getSimpleValueType();
4402   }
4403   if (Node->getOpcode() == ISD::STRICT_UINT_TO_FP ||
4404       Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
4405       Node->getOpcode() == ISD::STRICT_FSETCC ||
4406       Node->getOpcode() == ISD::STRICT_FSETCCS)
4407     OVT = Node->getOperand(1).getSimpleValueType();
4408   if (Node->getOpcode() == ISD::BR_CC ||
4409       Node->getOpcode() == ISD::SELECT_CC)
4410     OVT = Node->getOperand(2).getSimpleValueType();
4411   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4412   SDLoc dl(Node);
4413   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
4414   switch (Node->getOpcode()) {
4415   case ISD::CTTZ:
4416   case ISD::CTTZ_ZERO_UNDEF:
4417   case ISD::CTLZ:
4418   case ISD::CTLZ_ZERO_UNDEF:
4419   case ISD::CTPOP:
4420     // Zero extend the argument unless its cttz, then use any_extend.
4421     if (Node->getOpcode() == ISD::CTTZ ||
4422         Node->getOpcode() == ISD::CTTZ_ZERO_UNDEF)
4423       Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4424     else
4425       Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4426 
4427     if (Node->getOpcode() == ISD::CTTZ) {
4428       // The count is the same in the promoted type except if the original
4429       // value was zero.  This can be handled by setting the bit just off
4430       // the top of the original type.
4431       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4432                                         OVT.getSizeInBits());
4433       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4434                          DAG.getConstant(TopBit, dl, NVT));
4435     }
4436     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4437     // already the correct result.
4438     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4439     if (Node->getOpcode() == ISD::CTLZ ||
4440         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4441       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4442       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4443                           DAG.getConstant(NVT.getSizeInBits() -
4444                                           OVT.getSizeInBits(), dl, NVT));
4445     }
4446     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4447     break;
4448   case ISD::BITREVERSE:
4449   case ISD::BSWAP: {
4450     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4451     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4452     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4453     Tmp1 = DAG.getNode(
4454         ISD::SRL, dl, NVT, Tmp1,
4455         DAG.getConstant(DiffBits, dl,
4456                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4457 
4458     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4459     break;
4460   }
4461   case ISD::FP_TO_UINT:
4462   case ISD::STRICT_FP_TO_UINT:
4463   case ISD::FP_TO_SINT:
4464   case ISD::STRICT_FP_TO_SINT:
4465     PromoteLegalFP_TO_INT(Node, dl, Results);
4466     break;
4467   case ISD::FP_TO_UINT_SAT:
4468   case ISD::FP_TO_SINT_SAT:
4469     Results.push_back(PromoteLegalFP_TO_INT_SAT(Node, dl));
4470     break;
4471   case ISD::UINT_TO_FP:
4472   case ISD::STRICT_UINT_TO_FP:
4473   case ISD::SINT_TO_FP:
4474   case ISD::STRICT_SINT_TO_FP:
4475     PromoteLegalINT_TO_FP(Node, dl, Results);
4476     break;
4477   case ISD::VAARG: {
4478     SDValue Chain = Node->getOperand(0); // Get the chain.
4479     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4480 
4481     unsigned TruncOp;
4482     if (OVT.isVector()) {
4483       TruncOp = ISD::BITCAST;
4484     } else {
4485       assert(OVT.isInteger()
4486         && "VAARG promotion is supported only for vectors or integer types");
4487       TruncOp = ISD::TRUNCATE;
4488     }
4489 
4490     // Perform the larger operation, then convert back
4491     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4492              Node->getConstantOperandVal(3));
4493     Chain = Tmp1.getValue(1);
4494 
4495     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4496 
4497     // Modified the chain result - switch anything that used the old chain to
4498     // use the new one.
4499     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4500     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4501     if (UpdatedNodes) {
4502       UpdatedNodes->insert(Tmp2.getNode());
4503       UpdatedNodes->insert(Chain.getNode());
4504     }
4505     ReplacedNode(Node);
4506     break;
4507   }
4508   case ISD::MUL:
4509   case ISD::SDIV:
4510   case ISD::SREM:
4511   case ISD::UDIV:
4512   case ISD::UREM:
4513   case ISD::AND:
4514   case ISD::OR:
4515   case ISD::XOR: {
4516     unsigned ExtOp, TruncOp;
4517     if (OVT.isVector()) {
4518       ExtOp   = ISD::BITCAST;
4519       TruncOp = ISD::BITCAST;
4520     } else {
4521       assert(OVT.isInteger() && "Cannot promote logic operation");
4522 
4523       switch (Node->getOpcode()) {
4524       default:
4525         ExtOp = ISD::ANY_EXTEND;
4526         break;
4527       case ISD::SDIV:
4528       case ISD::SREM:
4529         ExtOp = ISD::SIGN_EXTEND;
4530         break;
4531       case ISD::UDIV:
4532       case ISD::UREM:
4533         ExtOp = ISD::ZERO_EXTEND;
4534         break;
4535       }
4536       TruncOp = ISD::TRUNCATE;
4537     }
4538     // Promote each of the values to the new type.
4539     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4540     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4541     // Perform the larger operation, then convert back
4542     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4543     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4544     break;
4545   }
4546   case ISD::UMUL_LOHI:
4547   case ISD::SMUL_LOHI: {
4548     // Promote to a multiply in a wider integer type.
4549     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4550                                                          : ISD::SIGN_EXTEND;
4551     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4552     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4553     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4554 
4555     auto &DL = DAG.getDataLayout();
4556     unsigned OriginalSize = OVT.getScalarSizeInBits();
4557     Tmp2 = DAG.getNode(
4558         ISD::SRL, dl, NVT, Tmp1,
4559         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4560     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4561     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4562     break;
4563   }
4564   case ISD::SELECT: {
4565     unsigned ExtOp, TruncOp;
4566     if (Node->getValueType(0).isVector() ||
4567         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4568       ExtOp   = ISD::BITCAST;
4569       TruncOp = ISD::BITCAST;
4570     } else if (Node->getValueType(0).isInteger()) {
4571       ExtOp   = ISD::ANY_EXTEND;
4572       TruncOp = ISD::TRUNCATE;
4573     } else {
4574       ExtOp   = ISD::FP_EXTEND;
4575       TruncOp = ISD::FP_ROUND;
4576     }
4577     Tmp1 = Node->getOperand(0);
4578     // Promote each of the values to the new type.
4579     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4580     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4581     // Perform the larger operation, then round down.
4582     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4583     Tmp1->setFlags(Node->getFlags());
4584     if (TruncOp != ISD::FP_ROUND)
4585       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4586     else
4587       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4588                          DAG.getIntPtrConstant(0, dl));
4589     Results.push_back(Tmp1);
4590     break;
4591   }
4592   case ISD::VECTOR_SHUFFLE: {
4593     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4594 
4595     // Cast the two input vectors.
4596     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4597     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4598 
4599     // Convert the shuffle mask to the right # elements.
4600     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4601     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4602     Results.push_back(Tmp1);
4603     break;
4604   }
4605   case ISD::VECTOR_SPLICE: {
4606     Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4607     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(1));
4608     Tmp3 = DAG.getNode(ISD::VECTOR_SPLICE, dl, NVT, Tmp1, Tmp2,
4609                        Node->getOperand(2));
4610     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp3));
4611     break;
4612   }
4613   case ISD::SELECT_CC: {
4614     SDValue Cond = Node->getOperand(4);
4615     ISD::CondCode CCCode = cast<CondCodeSDNode>(Cond)->get();
4616     // Type of the comparison operands.
4617     MVT CVT = Node->getSimpleValueType(0);
4618     assert(CVT == OVT && "not handled");
4619 
4620     unsigned ExtOp = ISD::FP_EXTEND;
4621     if (NVT.isInteger()) {
4622       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4623     }
4624 
4625     // Promote the comparison operands, if needed.
4626     if (TLI.isCondCodeLegal(CCCode, CVT)) {
4627       Tmp1 = Node->getOperand(0);
4628       Tmp2 = Node->getOperand(1);
4629     } else {
4630       Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4631       Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4632     }
4633     // Cast the true/false operands.
4634     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4635     Tmp4 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4636 
4637     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, NVT, {Tmp1, Tmp2, Tmp3, Tmp4, Cond},
4638                        Node->getFlags());
4639 
4640     // Cast the result back to the original type.
4641     if (ExtOp != ISD::FP_EXTEND)
4642       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1);
4643     else
4644       Tmp1 = DAG.getNode(ISD::FP_ROUND, dl, OVT, Tmp1,
4645                          DAG.getIntPtrConstant(0, dl));
4646 
4647     Results.push_back(Tmp1);
4648     break;
4649   }
4650   case ISD::SETCC:
4651   case ISD::STRICT_FSETCC:
4652   case ISD::STRICT_FSETCCS: {
4653     unsigned ExtOp = ISD::FP_EXTEND;
4654     if (NVT.isInteger()) {
4655       ISD::CondCode CCCode = cast<CondCodeSDNode>(Node->getOperand(2))->get();
4656       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4657     }
4658     if (Node->isStrictFPOpcode()) {
4659       SDValue InChain = Node->getOperand(0);
4660       std::tie(Tmp1, std::ignore) =
4661           DAG.getStrictFPExtendOrRound(Node->getOperand(1), InChain, dl, NVT);
4662       std::tie(Tmp2, std::ignore) =
4663           DAG.getStrictFPExtendOrRound(Node->getOperand(2), InChain, dl, NVT);
4664       SmallVector<SDValue, 2> TmpChains = {Tmp1.getValue(1), Tmp2.getValue(1)};
4665       SDValue OutChain = DAG.getTokenFactor(dl, TmpChains);
4666       SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
4667       Results.push_back(DAG.getNode(Node->getOpcode(), dl, VTs,
4668                                     {OutChain, Tmp1, Tmp2, Node->getOperand(3)},
4669                                     Node->getFlags()));
4670       Results.push_back(Results.back().getValue(1));
4671       break;
4672     }
4673     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4674     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4675     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0), Tmp1,
4676                                   Tmp2, Node->getOperand(2), Node->getFlags()));
4677     break;
4678   }
4679   case ISD::BR_CC: {
4680     unsigned ExtOp = ISD::FP_EXTEND;
4681     if (NVT.isInteger()) {
4682       ISD::CondCode CCCode =
4683         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4684       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4685     }
4686     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4687     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4688     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4689                                   Node->getOperand(0), Node->getOperand(1),
4690                                   Tmp1, Tmp2, Node->getOperand(4)));
4691     break;
4692   }
4693   case ISD::FADD:
4694   case ISD::FSUB:
4695   case ISD::FMUL:
4696   case ISD::FDIV:
4697   case ISD::FREM:
4698   case ISD::FMINNUM:
4699   case ISD::FMAXNUM:
4700   case ISD::FPOW:
4701     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4702     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4703     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4704                        Node->getFlags());
4705     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4706                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4707     break;
4708   case ISD::STRICT_FREM:
4709   case ISD::STRICT_FPOW:
4710     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4711                        {Node->getOperand(0), Node->getOperand(1)});
4712     Tmp2 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4713                        {Node->getOperand(0), Node->getOperand(2)});
4714     Tmp3 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Tmp1.getValue(1),
4715                        Tmp2.getValue(1));
4716     Tmp1 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4717                        {Tmp3, Tmp1, Tmp2});
4718     Tmp1 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4719                        {Tmp1.getValue(1), Tmp1, DAG.getIntPtrConstant(0, dl)});
4720     Results.push_back(Tmp1);
4721     Results.push_back(Tmp1.getValue(1));
4722     break;
4723   case ISD::FMA:
4724     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4725     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4726     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4727     Results.push_back(
4728         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4729                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4730                     DAG.getIntPtrConstant(0, dl)));
4731     break;
4732   case ISD::FCOPYSIGN:
4733   case ISD::FPOWI: {
4734     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4735     Tmp2 = Node->getOperand(1);
4736     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4737 
4738     // fcopysign doesn't change anything but the sign bit, so
4739     //   (fp_round (fcopysign (fpext a), b))
4740     // is as precise as
4741     //   (fp_round (fpext a))
4742     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4743     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4744     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4745                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4746     break;
4747   }
4748   case ISD::FFLOOR:
4749   case ISD::FCEIL:
4750   case ISD::FRINT:
4751   case ISD::FNEARBYINT:
4752   case ISD::FROUND:
4753   case ISD::FROUNDEVEN:
4754   case ISD::FTRUNC:
4755   case ISD::FNEG:
4756   case ISD::FSQRT:
4757   case ISD::FSIN:
4758   case ISD::FCOS:
4759   case ISD::FLOG:
4760   case ISD::FLOG2:
4761   case ISD::FLOG10:
4762   case ISD::FABS:
4763   case ISD::FEXP:
4764   case ISD::FEXP2:
4765     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4766     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4767     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4768                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4769     break;
4770   case ISD::STRICT_FFLOOR:
4771   case ISD::STRICT_FCEIL:
4772   case ISD::STRICT_FROUND:
4773   case ISD::STRICT_FSIN:
4774   case ISD::STRICT_FCOS:
4775   case ISD::STRICT_FLOG:
4776   case ISD::STRICT_FLOG10:
4777   case ISD::STRICT_FEXP:
4778     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4779                        {Node->getOperand(0), Node->getOperand(1)});
4780     Tmp2 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4781                        {Tmp1.getValue(1), Tmp1});
4782     Tmp3 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4783                        {Tmp2.getValue(1), Tmp2, DAG.getIntPtrConstant(0, dl)});
4784     Results.push_back(Tmp3);
4785     Results.push_back(Tmp3.getValue(1));
4786     break;
4787   case ISD::BUILD_VECTOR: {
4788     MVT EltVT = OVT.getVectorElementType();
4789     MVT NewEltVT = NVT.getVectorElementType();
4790 
4791     // Handle bitcasts to a different vector type with the same total bit size
4792     //
4793     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4794     //  =>
4795     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4796 
4797     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4798            "Invalid promote type for build_vector");
4799     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4800 
4801     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4802 
4803     SmallVector<SDValue, 8> NewOps;
4804     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4805       SDValue Op = Node->getOperand(I);
4806       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4807     }
4808 
4809     SDLoc SL(Node);
4810     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4811     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4812     Results.push_back(CvtVec);
4813     break;
4814   }
4815   case ISD::EXTRACT_VECTOR_ELT: {
4816     MVT EltVT = OVT.getVectorElementType();
4817     MVT NewEltVT = NVT.getVectorElementType();
4818 
4819     // Handle bitcasts to a different vector type with the same total bit size.
4820     //
4821     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4822     //  =>
4823     //  v4i32:castx = bitcast x:v2i64
4824     //
4825     // i64 = bitcast
4826     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4827     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4828     //
4829 
4830     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4831            "Invalid promote type for extract_vector_elt");
4832     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4833 
4834     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4835     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4836 
4837     SDValue Idx = Node->getOperand(1);
4838     EVT IdxVT = Idx.getValueType();
4839     SDLoc SL(Node);
4840     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4841     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4842 
4843     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4844 
4845     SmallVector<SDValue, 8> NewOps;
4846     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4847       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4848       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4849 
4850       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4851                                 CastVec, TmpIdx);
4852       NewOps.push_back(Elt);
4853     }
4854 
4855     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4856     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4857     break;
4858   }
4859   case ISD::INSERT_VECTOR_ELT: {
4860     MVT EltVT = OVT.getVectorElementType();
4861     MVT NewEltVT = NVT.getVectorElementType();
4862 
4863     // Handle bitcasts to a different vector type with the same total bit size
4864     //
4865     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4866     //  =>
4867     //  v4i32:castx = bitcast x:v2i64
4868     //  v2i32:casty = bitcast y:i64
4869     //
4870     // v2i64 = bitcast
4871     //   (v4i32 insert_vector_elt
4872     //       (v4i32 insert_vector_elt v4i32:castx,
4873     //                                (extract_vector_elt casty, 0), 2 * z),
4874     //        (extract_vector_elt casty, 1), (2 * z + 1))
4875 
4876     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4877            "Invalid promote type for insert_vector_elt");
4878     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4879 
4880     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4881     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4882 
4883     SDValue Val = Node->getOperand(1);
4884     SDValue Idx = Node->getOperand(2);
4885     EVT IdxVT = Idx.getValueType();
4886     SDLoc SL(Node);
4887 
4888     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4889     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4890 
4891     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4892     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4893 
4894     SDValue NewVec = CastVec;
4895     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4896       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4897       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4898 
4899       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4900                                 CastVal, IdxOffset);
4901 
4902       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4903                            NewVec, Elt, InEltIdx);
4904     }
4905 
4906     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4907     break;
4908   }
4909   case ISD::SCALAR_TO_VECTOR: {
4910     MVT EltVT = OVT.getVectorElementType();
4911     MVT NewEltVT = NVT.getVectorElementType();
4912 
4913     // Handle bitcasts to different vector type with the same total bit size.
4914     //
4915     // e.g. v2i64 = scalar_to_vector x:i64
4916     //   =>
4917     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4918     //
4919 
4920     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4921     SDValue Val = Node->getOperand(0);
4922     SDLoc SL(Node);
4923 
4924     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4925     SDValue Undef = DAG.getUNDEF(MidVT);
4926 
4927     SmallVector<SDValue, 8> NewElts;
4928     NewElts.push_back(CastVal);
4929     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4930       NewElts.push_back(Undef);
4931 
4932     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4933     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4934     Results.push_back(CvtVec);
4935     break;
4936   }
4937   case ISD::ATOMIC_SWAP: {
4938     AtomicSDNode *AM = cast<AtomicSDNode>(Node);
4939     SDLoc SL(Node);
4940     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NVT, AM->getVal());
4941     assert(NVT.getSizeInBits() == OVT.getSizeInBits() &&
4942            "unexpected promotion type");
4943     assert(AM->getMemoryVT().getSizeInBits() == NVT.getSizeInBits() &&
4944            "unexpected atomic_swap with illegal type");
4945 
4946     SDValue NewAtomic
4947       = DAG.getAtomic(ISD::ATOMIC_SWAP, SL, NVT,
4948                       DAG.getVTList(NVT, MVT::Other),
4949                       { AM->getChain(), AM->getBasePtr(), CastVal },
4950                       AM->getMemOperand());
4951     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewAtomic));
4952     Results.push_back(NewAtomic.getValue(1));
4953     break;
4954   }
4955   }
4956 
4957   // Replace the original node with the legalized result.
4958   if (!Results.empty()) {
4959     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4960     ReplaceNode(Node, Results.data());
4961   } else
4962     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4963 }
4964 
4965 /// This is the entry point for the file.
4966 void SelectionDAG::Legalize() {
4967   AssignTopologicalOrder();
4968 
4969   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4970   // Use a delete listener to remove nodes which were deleted during
4971   // legalization from LegalizeNodes. This is needed to handle the situation
4972   // where a new node is allocated by the object pool to the same address of a
4973   // previously deleted node.
4974   DAGNodeDeletedListener DeleteListener(
4975       *this,
4976       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4977 
4978   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4979 
4980   // Visit all the nodes. We start in topological order, so that we see
4981   // nodes with their original operands intact. Legalization can produce
4982   // new nodes which may themselves need to be legalized. Iterate until all
4983   // nodes have been legalized.
4984   while (true) {
4985     bool AnyLegalized = false;
4986     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4987       --NI;
4988 
4989       SDNode *N = &*NI;
4990       if (N->use_empty() && N != getRoot().getNode()) {
4991         ++NI;
4992         DeleteNode(N);
4993         continue;
4994       }
4995 
4996       if (LegalizedNodes.insert(N).second) {
4997         AnyLegalized = true;
4998         Legalizer.LegalizeOp(N);
4999 
5000         if (N->use_empty() && N != getRoot().getNode()) {
5001           ++NI;
5002           DeleteNode(N);
5003         }
5004       }
5005     }
5006     if (!AnyLegalized)
5007       break;
5008 
5009   }
5010 
5011   // Remove dead nodes now.
5012   RemoveDeadNodes();
5013 }
5014 
5015 bool SelectionDAG::LegalizeOp(SDNode *N,
5016                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
5017   SmallPtrSet<SDNode *, 16> LegalizedNodes;
5018   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
5019 
5020   // Directly insert the node in question, and legalize it. This will recurse
5021   // as needed through operands.
5022   LegalizedNodes.insert(N);
5023   Legalizer.LegalizeOp(N);
5024 
5025   return LegalizedNodes.count(N);
5026 }
5027