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