1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the SelectionDAG::Legalize method.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/APFloat.h"
14 #include "llvm/ADT/APInt.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/SetVector.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/SmallSet.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/Analysis/TargetLibraryInfo.h"
21 #include "llvm/CodeGen/ISDOpcodes.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/RuntimeLibcalls.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGNodes.h"
28 #include "llvm/CodeGen/TargetFrameLowering.h"
29 #include "llvm/CodeGen/TargetLowering.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/CodeGen/ValueTypes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/MachineValueType.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include <algorithm>
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
137                              bool &NeedInvert, const SDLoc &dl, SDValue &Chain,
138                              bool IsSignaling = false);
139 
140   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
141 
142   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
143                        RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
144                        RTLIB::Libcall Call_F128,
145                        RTLIB::Libcall Call_PPCF128,
146                        SmallVectorImpl<SDValue> &Results);
147   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
148                            RTLIB::Libcall Call_I8,
149                            RTLIB::Libcall Call_I16,
150                            RTLIB::Libcall Call_I32,
151                            RTLIB::Libcall Call_I64,
152                            RTLIB::Libcall Call_I128);
153   void ExpandArgFPLibCall(SDNode *Node,
154                           RTLIB::Libcall Call_F32, RTLIB::Libcall Call_F64,
155                           RTLIB::Libcall Call_F80, RTLIB::Libcall Call_F128,
156                           RTLIB::Libcall Call_PPCF128,
157                           SmallVectorImpl<SDValue> &Results);
158   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
159   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
160 
161   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
162                            const SDLoc &dl);
163   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
164                            const SDLoc &dl, SDValue ChainIn);
165   SDValue ExpandBUILD_VECTOR(SDNode *Node);
166   SDValue ExpandSPLAT_VECTOR(SDNode *Node);
167   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
168   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
169                                 SmallVectorImpl<SDValue> &Results);
170   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
171                          SDValue Value) const;
172   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
173                           SDValue NewIntValue) const;
174   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
175   SDValue ExpandFABS(SDNode *Node) const;
176   SDValue ExpandLegalINT_TO_FP(SDNode *Node, SDValue &Chain);
177   void PromoteLegalINT_TO_FP(SDNode *N, const SDLoc &dl,
178                              SmallVectorImpl<SDValue> &Results);
179   void PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
180                              SmallVectorImpl<SDValue> &Results);
181 
182   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
183   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
184   SDValue ExpandPARITY(SDValue Op, const SDLoc &dl);
185 
186   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
187   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
188   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
189 
190   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
191   SDValue ExpandConstant(ConstantSDNode *CP);
192 
193   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
194   bool ExpandNode(SDNode *Node);
195   void ConvertNodeToLibcall(SDNode *Node);
196   void PromoteNode(SDNode *Node);
197 
198 public:
199   // Node replacement helpers
200 
201   void ReplacedNode(SDNode *N) {
202     LegalizedNodes.erase(N);
203     if (UpdatedNodes)
204       UpdatedNodes->insert(N);
205   }
206 
207   void ReplaceNode(SDNode *Old, SDNode *New) {
208     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
209                dbgs() << "     with:      "; New->dump(&DAG));
210 
211     assert(Old->getNumValues() == New->getNumValues() &&
212            "Replacing one node with another that produces a different number "
213            "of values!");
214     DAG.ReplaceAllUsesWith(Old, New);
215     if (UpdatedNodes)
216       UpdatedNodes->insert(New);
217     ReplacedNode(Old);
218   }
219 
220   void ReplaceNode(SDValue Old, SDValue New) {
221     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
222                dbgs() << "     with:      "; New->dump(&DAG));
223 
224     DAG.ReplaceAllUsesWith(Old, New);
225     if (UpdatedNodes)
226       UpdatedNodes->insert(New.getNode());
227     ReplacedNode(Old.getNode());
228   }
229 
230   void ReplaceNode(SDNode *Old, const SDValue *New) {
231     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
232 
233     DAG.ReplaceAllUsesWith(Old, New);
234     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
235       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
236                  New[i]->dump(&DAG));
237       if (UpdatedNodes)
238         UpdatedNodes->insert(New[i].getNode());
239     }
240     ReplacedNode(Old);
241   }
242 
243   void ReplaceNodeWithValue(SDValue Old, SDValue New) {
244     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
245                dbgs() << "     with:      "; New->dump(&DAG));
246 
247     DAG.ReplaceAllUsesOfValueWith(Old, New);
248     if (UpdatedNodes)
249       UpdatedNodes->insert(New.getNode());
250     ReplacedNode(Old.getNode());
251   }
252 };
253 
254 } // end anonymous namespace
255 
256 /// Return a vector shuffle operation which
257 /// performs the same shuffle in terms of order or result bytes, but on a type
258 /// whose vector element type is narrower than the original shuffle type.
259 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
260 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
261     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
262     ArrayRef<int> Mask) const {
263   unsigned NumMaskElts = VT.getVectorNumElements();
264   unsigned NumDestElts = NVT.getVectorNumElements();
265   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
266 
267   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
268 
269   if (NumEltsGrowth == 1)
270     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
271 
272   SmallVector<int, 8> NewMask;
273   for (unsigned i = 0; i != NumMaskElts; ++i) {
274     int Idx = Mask[i];
275     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
276       if (Idx < 0)
277         NewMask.push_back(-1);
278       else
279         NewMask.push_back(Idx * NumEltsGrowth + j);
280     }
281   }
282   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
283   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
284   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
285 }
286 
287 /// Expands the ConstantFP node to an integer constant or
288 /// a load from the constant pool.
289 SDValue
290 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
291   bool Extend = false;
292   SDLoc dl(CFP);
293 
294   // If a FP immediate is precise when represented as a float and if the
295   // target can do an extending load from float to double, we put it into
296   // the constant pool as a float, even if it's is statically typed as a
297   // double.  This shrinks FP constants and canonicalizes them for targets where
298   // an FP extending load is the same cost as a normal load (such as on the x87
299   // fp stack or PPC FP unit).
300   EVT VT = CFP->getValueType(0);
301   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
302   if (!UseCP) {
303     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
304     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
305                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
306   }
307 
308   APFloat APF = CFP->getValueAPF();
309   EVT OrigVT = VT;
310   EVT SVT = VT;
311 
312   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
313   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
314   if (!APF.isSignaling()) {
315     while (SVT != MVT::f32 && SVT != MVT::f16) {
316       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
317       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
318           // Only do this if the target has a native EXTLOAD instruction from
319           // smaller type.
320           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
321           TLI.ShouldShrinkFPConstant(OrigVT)) {
322         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
323         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
324         VT = SVT;
325         Extend = true;
326       }
327     }
328   }
329 
330   SDValue CPIdx =
331       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
332   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
333   if (Extend) {
334     SDValue Result = DAG.getExtLoad(
335         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
336         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
337         Alignment);
338     return Result;
339   }
340   SDValue Result = DAG.getLoad(
341       OrigVT, dl, DAG.getEntryNode(), CPIdx,
342       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
343   return Result;
344 }
345 
346 /// Expands the Constant node to a load from the constant pool.
347 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
348   SDLoc dl(CP);
349   EVT VT = CP->getValueType(0);
350   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
351                                       TLI.getPointerTy(DAG.getDataLayout()));
352   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
353   SDValue Result = DAG.getLoad(
354       VT, dl, DAG.getEntryNode(), CPIdx,
355       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
356   return Result;
357 }
358 
359 /// Some target cannot handle a variable insertion index for the
360 /// INSERT_VECTOR_ELT instruction.  In this case, it
361 /// is necessary to spill the vector being inserted into to memory, perform
362 /// the insert there, and then read the result back.
363 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
364                                                              SDValue Val,
365                                                              SDValue Idx,
366                                                              const SDLoc &dl) {
367   SDValue Tmp1 = Vec;
368   SDValue Tmp2 = Val;
369   SDValue Tmp3 = Idx;
370 
371   // If the target doesn't support this, we have to spill the input vector
372   // to a temporary stack slot, update the element, then reload it.  This is
373   // badness.  We could also load the value into a vector register (either
374   // with a "move to register" or "extload into register" instruction, then
375   // permute it into place, if the idx is a constant and if the idx is
376   // supported by the target.
377   EVT VT    = Tmp1.getValueType();
378   EVT EltVT = VT.getVectorElementType();
379   SDValue StackPtr = DAG.CreateStackTemporary(VT);
380 
381   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
382 
383   // Store the vector.
384   SDValue Ch = DAG.getStore(
385       DAG.getEntryNode(), dl, Tmp1, StackPtr,
386       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
387 
388   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
389 
390   // Store the scalar value.
391   Ch = DAG.getTruncStore(
392       Ch, dl, Tmp2, StackPtr2,
393       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()), EltVT);
394   // Load the updated vector.
395   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
396                                                DAG.getMachineFunction(), SPFI));
397 }
398 
399 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
400                                                       SDValue Idx,
401                                                       const SDLoc &dl) {
402   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
403     // SCALAR_TO_VECTOR requires that the type of the value being inserted
404     // match the element type of the vector being created, except for
405     // integers in which case the inserted value can be over width.
406     EVT EltVT = Vec.getValueType().getVectorElementType();
407     if (Val.getValueType() == EltVT ||
408         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
409       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
410                                   Vec.getValueType(), Val);
411 
412       unsigned NumElts = Vec.getValueType().getVectorNumElements();
413       // We generate a shuffle of InVec and ScVec, so the shuffle mask
414       // should be 0,1,2,3,4,5... with the appropriate element replaced with
415       // elt 0 of the RHS.
416       SmallVector<int, 8> ShufOps;
417       for (unsigned i = 0; i != NumElts; ++i)
418         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
419 
420       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
421     }
422   }
423   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
424 }
425 
426 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
427   if (!ISD::isNormalStore(ST))
428     return SDValue();
429 
430   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
431   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
432   // FIXME: We shouldn't do this for TargetConstantFP's.
433   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
434   // to phase ordering between legalized code and the dag combiner.  This
435   // probably means that we need to integrate dag combiner and legalizer
436   // together.
437   // We generally can't do this one for long doubles.
438   SDValue Chain = ST->getChain();
439   SDValue Ptr = ST->getBasePtr();
440   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
441   AAMDNodes AAInfo = ST->getAAInfo();
442   SDLoc dl(ST);
443   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
444     if (CFP->getValueType(0) == MVT::f32 &&
445         TLI.isTypeLegal(MVT::i32)) {
446       SDValue Con = DAG.getConstant(CFP->getValueAPF().
447                                       bitcastToAPInt().zextOrTrunc(32),
448                                     SDLoc(CFP), MVT::i32);
449       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
450                           ST->getOriginalAlign(), MMOFlags, AAInfo);
451     }
452 
453     if (CFP->getValueType(0) == MVT::f64) {
454       // If this target supports 64-bit registers, do a single 64-bit store.
455       if (TLI.isTypeLegal(MVT::i64)) {
456         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
457                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
458         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
459                             ST->getOriginalAlign(), MMOFlags, AAInfo);
460       }
461 
462       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
463         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
464         // stores.  If the target supports neither 32- nor 64-bits, this
465         // xform is certainly not worth it.
466         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
467         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
468         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
469         if (DAG.getDataLayout().isBigEndian())
470           std::swap(Lo, Hi);
471 
472         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(),
473                           ST->getOriginalAlign(), MMOFlags, AAInfo);
474         Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(4), dl);
475         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
476                           ST->getPointerInfo().getWithOffset(4),
477                           ST->getOriginalAlign(), MMOFlags, AAInfo);
478 
479         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
480       }
481     }
482   }
483   return SDValue(nullptr, 0);
484 }
485 
486 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
487   StoreSDNode *ST = cast<StoreSDNode>(Node);
488   SDValue Chain = ST->getChain();
489   SDValue Ptr = ST->getBasePtr();
490   SDLoc dl(Node);
491 
492   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
493   AAMDNodes AAInfo = ST->getAAInfo();
494 
495   if (!ST->isTruncatingStore()) {
496     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
497     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
498       ReplaceNode(ST, OptStore);
499       return;
500     }
501 
502     SDValue Value = ST->getValue();
503     MVT VT = Value.getSimpleValueType();
504     switch (TLI.getOperationAction(ISD::STORE, VT)) {
505     default: llvm_unreachable("This action is not supported yet!");
506     case TargetLowering::Legal: {
507       // If this is an unaligned store and the target doesn't support it,
508       // expand it.
509       EVT MemVT = ST->getMemoryVT();
510       const DataLayout &DL = DAG.getDataLayout();
511       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
512                                               *ST->getMemOperand())) {
513         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
514         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
515         ReplaceNode(SDValue(ST, 0), Result);
516       } else
517         LLVM_DEBUG(dbgs() << "Legal store\n");
518       break;
519     }
520     case TargetLowering::Custom: {
521       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
522       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
523       if (Res && Res != SDValue(Node, 0))
524         ReplaceNode(SDValue(Node, 0), Res);
525       return;
526     }
527     case TargetLowering::Promote: {
528       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
529       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
530              "Can only promote stores to same size type");
531       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
532       SDValue Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
533                                     ST->getOriginalAlign(), MMOFlags, AAInfo);
534       ReplaceNode(SDValue(Node, 0), Result);
535       break;
536     }
537     }
538     return;
539   }
540 
541   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
542   SDValue Value = ST->getValue();
543   EVT StVT = ST->getMemoryVT();
544   unsigned StWidth = StVT.getSizeInBits();
545   auto &DL = DAG.getDataLayout();
546 
547   if (StWidth != StVT.getStoreSizeInBits()) {
548     // Promote to a byte-sized store with upper bits zero if not
549     // storing an integral number of bytes.  For example, promote
550     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
551     EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
552                                 StVT.getStoreSizeInBits());
553     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
554     SDValue Result =
555         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
556                           ST->getOriginalAlign(), MMOFlags, AAInfo);
557     ReplaceNode(SDValue(Node, 0), Result);
558   } else if (StWidth & (StWidth - 1)) {
559     // If not storing a power-of-2 number of bits, expand as two stores.
560     assert(!StVT.isVector() && "Unsupported truncstore!");
561     unsigned LogStWidth = Log2_32(StWidth);
562     assert(LogStWidth < 32);
563     unsigned RoundWidth = 1 << LogStWidth;
564     assert(RoundWidth < StWidth);
565     unsigned ExtraWidth = StWidth - RoundWidth;
566     assert(ExtraWidth < RoundWidth);
567     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
568            "Store size not an integral number of bytes!");
569     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
570     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
571     SDValue Lo, Hi;
572     unsigned IncrementSize;
573 
574     if (DL.isLittleEndian()) {
575       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
576       // Store the bottom RoundWidth bits.
577       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
578                              RoundVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
579 
580       // Store the remaining ExtraWidth bits.
581       IncrementSize = RoundWidth / 8;
582       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
583       Hi = DAG.getNode(
584           ISD::SRL, dl, Value.getValueType(), Value,
585           DAG.getConstant(RoundWidth, dl,
586                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
587       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
588                              ST->getPointerInfo().getWithOffset(IncrementSize),
589                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
590     } else {
591       // Big endian - avoid unaligned stores.
592       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
593       // Store the top RoundWidth bits.
594       Hi = DAG.getNode(
595           ISD::SRL, dl, Value.getValueType(), Value,
596           DAG.getConstant(ExtraWidth, dl,
597                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
598       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(), RoundVT,
599                              ST->getOriginalAlign(), MMOFlags, AAInfo);
600 
601       // Store the remaining ExtraWidth bits.
602       IncrementSize = RoundWidth / 8;
603       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
604                         DAG.getConstant(IncrementSize, dl,
605                                         Ptr.getValueType()));
606       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
607                              ST->getPointerInfo().getWithOffset(IncrementSize),
608                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
609     }
610 
611     // The order of the stores doesn't matter.
612     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
613     ReplaceNode(SDValue(Node, 0), Result);
614   } else {
615     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
616     default: llvm_unreachable("This action is not supported yet!");
617     case TargetLowering::Legal: {
618       EVT MemVT = ST->getMemoryVT();
619       // If this is an unaligned store and the target doesn't support it,
620       // expand it.
621       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
622                                               *ST->getMemOperand())) {
623         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
624         ReplaceNode(SDValue(ST, 0), Result);
625       }
626       break;
627     }
628     case TargetLowering::Custom: {
629       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
630       if (Res && Res != SDValue(Node, 0))
631         ReplaceNode(SDValue(Node, 0), Res);
632       return;
633     }
634     case TargetLowering::Expand:
635       assert(!StVT.isVector() &&
636              "Vector Stores are handled in LegalizeVectorOps");
637 
638       SDValue Result;
639 
640       // TRUNCSTORE:i16 i32 -> STORE i16
641       if (TLI.isTypeLegal(StVT)) {
642         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
643         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
644                               ST->getOriginalAlign(), MMOFlags, AAInfo);
645       } else {
646         // The in-memory type isn't legal. Truncate to the type it would promote
647         // to, and then do a truncstore.
648         Value = DAG.getNode(ISD::TRUNCATE, dl,
649                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
650                             Value);
651         Result =
652             DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), StVT,
653                               ST->getOriginalAlign(), MMOFlags, AAInfo);
654       }
655 
656       ReplaceNode(SDValue(Node, 0), Result);
657       break;
658     }
659   }
660 }
661 
662 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
663   LoadSDNode *LD = cast<LoadSDNode>(Node);
664   SDValue Chain = LD->getChain();  // The chain.
665   SDValue Ptr = LD->getBasePtr();  // The base pointer.
666   SDValue Value;                   // The value returned by the load op.
667   SDLoc dl(Node);
668 
669   ISD::LoadExtType ExtType = LD->getExtensionType();
670   if (ExtType == ISD::NON_EXTLOAD) {
671     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
672     MVT VT = Node->getSimpleValueType(0);
673     SDValue RVal = SDValue(Node, 0);
674     SDValue RChain = SDValue(Node, 1);
675 
676     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
677     default: llvm_unreachable("This action is not supported yet!");
678     case TargetLowering::Legal: {
679       EVT MemVT = LD->getMemoryVT();
680       const DataLayout &DL = DAG.getDataLayout();
681       // If this is an unaligned load and the target doesn't support it,
682       // expand it.
683       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
684                                               *LD->getMemOperand())) {
685         std::tie(RVal, RChain) = TLI.expandUnalignedLoad(LD, DAG);
686       }
687       break;
688     }
689     case TargetLowering::Custom:
690       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
691         RVal = Res;
692         RChain = Res.getValue(1);
693       }
694       break;
695 
696     case TargetLowering::Promote: {
697       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
698       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
699              "Can only promote loads to same size type");
700 
701       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
702       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
703       RChain = Res.getValue(1);
704       break;
705     }
706     }
707     if (RChain.getNode() != Node) {
708       assert(RVal.getNode() != Node && "Load must be completely replaced");
709       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
710       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
711       if (UpdatedNodes) {
712         UpdatedNodes->insert(RVal.getNode());
713         UpdatedNodes->insert(RChain.getNode());
714       }
715       ReplacedNode(Node);
716     }
717     return;
718   }
719 
720   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
721   EVT SrcVT = LD->getMemoryVT();
722   TypeSize SrcWidth = SrcVT.getSizeInBits();
723   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
724   AAMDNodes AAInfo = LD->getAAInfo();
725 
726   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
727       // Some targets pretend to have an i1 loading operation, and actually
728       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
729       // bits are guaranteed to be zero; it helps the optimizers understand
730       // that these bits are zero.  It is also useful for EXTLOAD, since it
731       // tells the optimizers that those bits are undefined.  It would be
732       // nice to have an effective generic way of getting these benefits...
733       // Until such a way is found, don't insist on promoting i1 here.
734       (SrcVT != MVT::i1 ||
735        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
736          TargetLowering::Promote)) {
737     // Promote to a byte-sized load if not loading an integral number of
738     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
739     unsigned NewWidth = SrcVT.getStoreSizeInBits();
740     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
741     SDValue Ch;
742 
743     // The extra bits are guaranteed to be zero, since we stored them that
744     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
745 
746     ISD::LoadExtType NewExtType =
747       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
748 
749     SDValue Result = DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
750                                     Chain, Ptr, LD->getPointerInfo(), NVT,
751                                     LD->getOriginalAlign(), MMOFlags, AAInfo);
752 
753     Ch = Result.getValue(1); // The chain.
754 
755     if (ExtType == ISD::SEXTLOAD)
756       // Having the top bits zero doesn't help when sign extending.
757       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
758                            Result.getValueType(),
759                            Result, DAG.getValueType(SrcVT));
760     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
761       // All the top bits are guaranteed to be zero - inform the optimizers.
762       Result = DAG.getNode(ISD::AssertZext, dl,
763                            Result.getValueType(), Result,
764                            DAG.getValueType(SrcVT));
765 
766     Value = Result;
767     Chain = Ch;
768   } else if (!isPowerOf2_64(SrcWidth.getKnownMinSize())) {
769     // If not loading a power-of-2 number of bits, expand as two loads.
770     assert(!SrcVT.isVector() && "Unsupported extload!");
771     unsigned SrcWidthBits = SrcWidth.getFixedSize();
772     unsigned LogSrcWidth = Log2_32(SrcWidthBits);
773     assert(LogSrcWidth < 32);
774     unsigned RoundWidth = 1 << LogSrcWidth;
775     assert(RoundWidth < SrcWidthBits);
776     unsigned ExtraWidth = SrcWidthBits - RoundWidth;
777     assert(ExtraWidth < RoundWidth);
778     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
779            "Load size not an integral number of bytes!");
780     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
781     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
782     SDValue Lo, Hi, Ch;
783     unsigned IncrementSize;
784     auto &DL = DAG.getDataLayout();
785 
786     if (DL.isLittleEndian()) {
787       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
788       // Load the bottom RoundWidth bits.
789       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
790                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
791                           MMOFlags, AAInfo);
792 
793       // Load the remaining ExtraWidth bits.
794       IncrementSize = RoundWidth / 8;
795       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
796       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
797                           LD->getPointerInfo().getWithOffset(IncrementSize),
798                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
799 
800       // Build a factor node to remember that this load is independent of
801       // the other one.
802       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
803                        Hi.getValue(1));
804 
805       // Move the top bits to the right place.
806       Hi = DAG.getNode(
807           ISD::SHL, dl, Hi.getValueType(), Hi,
808           DAG.getConstant(RoundWidth, dl,
809                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
810 
811       // Join the hi and lo parts.
812       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
813     } else {
814       // Big endian - avoid unaligned loads.
815       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
816       // Load the top RoundWidth bits.
817       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
818                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
819                           MMOFlags, AAInfo);
820 
821       // Load the remaining ExtraWidth bits.
822       IncrementSize = RoundWidth / 8;
823       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
824       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
825                           LD->getPointerInfo().getWithOffset(IncrementSize),
826                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
827 
828       // Build a factor node to remember that this load is independent of
829       // the other one.
830       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
831                        Hi.getValue(1));
832 
833       // Move the top bits to the right place.
834       Hi = DAG.getNode(
835           ISD::SHL, dl, Hi.getValueType(), Hi,
836           DAG.getConstant(ExtraWidth, dl,
837                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
838 
839       // Join the hi and lo parts.
840       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
841     }
842 
843     Chain = Ch;
844   } else {
845     bool isCustom = false;
846     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
847                                  SrcVT.getSimpleVT())) {
848     default: llvm_unreachable("This action is not supported yet!");
849     case TargetLowering::Custom:
850       isCustom = true;
851       LLVM_FALLTHROUGH;
852     case TargetLowering::Legal:
853       Value = SDValue(Node, 0);
854       Chain = SDValue(Node, 1);
855 
856       if (isCustom) {
857         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
858           Value = Res;
859           Chain = Res.getValue(1);
860         }
861       } else {
862         // If this is an unaligned load and the target doesn't support it,
863         // expand it.
864         EVT MemVT = LD->getMemoryVT();
865         const DataLayout &DL = DAG.getDataLayout();
866         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT,
867                                     *LD->getMemOperand())) {
868           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
869         }
870       }
871       break;
872 
873     case TargetLowering::Expand: {
874       EVT DestVT = Node->getValueType(0);
875       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
876         // If the source type is not legal, see if there is a legal extload to
877         // an intermediate type that we can then extend further.
878         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
879         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
880             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
881           // If we are loading a legal type, this is a non-extload followed by a
882           // full extend.
883           ISD::LoadExtType MidExtType =
884               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
885 
886           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
887                                         SrcVT, LD->getMemOperand());
888           unsigned ExtendOp =
889               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
890           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
891           Chain = Load.getValue(1);
892           break;
893         }
894 
895         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
896         // normal undefined upper bits behavior to allow using an in-reg extend
897         // with the illegal FP type, so load as an integer and do the
898         // from-integer conversion.
899         if (SrcVT.getScalarType() == MVT::f16) {
900           EVT ISrcVT = SrcVT.changeTypeToInteger();
901           EVT IDestVT = DestVT.changeTypeToInteger();
902           EVT ILoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
903 
904           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, ILoadVT, Chain,
905                                           Ptr, ISrcVT, LD->getMemOperand());
906           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
907           Chain = Result.getValue(1);
908           break;
909         }
910       }
911 
912       assert(!SrcVT.isVector() &&
913              "Vector Loads are handled in LegalizeVectorOps");
914 
915       // FIXME: This does not work for vectors on most targets.  Sign-
916       // and zero-extend operations are currently folded into extending
917       // loads, whether they are legal or not, and then we end up here
918       // without any support for legalizing them.
919       assert(ExtType != ISD::EXTLOAD &&
920              "EXTLOAD should always be supported!");
921       // Turn the unsupported load into an EXTLOAD followed by an
922       // explicit zero/sign extend inreg.
923       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
924                                       Node->getValueType(0),
925                                       Chain, Ptr, SrcVT,
926                                       LD->getMemOperand());
927       SDValue ValRes;
928       if (ExtType == ISD::SEXTLOAD)
929         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
930                              Result.getValueType(),
931                              Result, DAG.getValueType(SrcVT));
932       else
933         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT);
934       Value = ValRes;
935       Chain = Result.getValue(1);
936       break;
937     }
938     }
939   }
940 
941   // Since loads produce two values, make sure to remember that we legalized
942   // both of them.
943   if (Chain.getNode() != Node) {
944     assert(Value.getNode() != Node && "Load must be completely replaced");
945     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
946     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
947     if (UpdatedNodes) {
948       UpdatedNodes->insert(Value.getNode());
949       UpdatedNodes->insert(Chain.getNode());
950     }
951     ReplacedNode(Node);
952   }
953 }
954 
955 /// Return a legal replacement for the given operation, with all legal operands.
956 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
957   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
958 
959   // Allow illegal target nodes and illegal registers.
960   if (Node->getOpcode() == ISD::TargetConstant ||
961       Node->getOpcode() == ISD::Register)
962     return;
963 
964 #ifndef NDEBUG
965   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
966     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
967              TargetLowering::TypeLegal &&
968            "Unexpected illegal type!");
969 
970   for (const SDValue &Op : Node->op_values())
971     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
972               TargetLowering::TypeLegal ||
973             Op.getOpcode() == ISD::TargetConstant ||
974             Op.getOpcode() == ISD::Register) &&
975             "Unexpected illegal type!");
976 #endif
977 
978   // Figure out the correct action; the way to query this varies by opcode
979   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
980   bool SimpleFinishLegalizing = true;
981   switch (Node->getOpcode()) {
982   case ISD::INTRINSIC_W_CHAIN:
983   case ISD::INTRINSIC_WO_CHAIN:
984   case ISD::INTRINSIC_VOID:
985   case ISD::STACKSAVE:
986     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
987     break;
988   case ISD::GET_DYNAMIC_AREA_OFFSET:
989     Action = TLI.getOperationAction(Node->getOpcode(),
990                                     Node->getValueType(0));
991     break;
992   case ISD::VAARG:
993     Action = TLI.getOperationAction(Node->getOpcode(),
994                                     Node->getValueType(0));
995     if (Action != TargetLowering::Promote)
996       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
997     break;
998   case ISD::FP_TO_FP16:
999   case ISD::SINT_TO_FP:
1000   case ISD::UINT_TO_FP:
1001   case ISD::EXTRACT_VECTOR_ELT:
1002   case ISD::LROUND:
1003   case ISD::LLROUND:
1004   case ISD::LRINT:
1005   case ISD::LLRINT:
1006     Action = TLI.getOperationAction(Node->getOpcode(),
1007                                     Node->getOperand(0).getValueType());
1008     break;
1009   case ISD::STRICT_FP_TO_FP16:
1010   case ISD::STRICT_SINT_TO_FP:
1011   case ISD::STRICT_UINT_TO_FP:
1012   case ISD::STRICT_LRINT:
1013   case ISD::STRICT_LLRINT:
1014   case ISD::STRICT_LROUND:
1015   case ISD::STRICT_LLROUND:
1016     // These pseudo-ops are the same as the other STRICT_ ops except
1017     // they are registered with setOperationAction() using the input type
1018     // instead of the output type.
1019     Action = TLI.getOperationAction(Node->getOpcode(),
1020                                     Node->getOperand(1).getValueType());
1021     break;
1022   case ISD::SIGN_EXTEND_INREG: {
1023     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1024     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1025     break;
1026   }
1027   case ISD::ATOMIC_STORE:
1028     Action = TLI.getOperationAction(Node->getOpcode(),
1029                                     Node->getOperand(2).getValueType());
1030     break;
1031   case ISD::SELECT_CC:
1032   case ISD::STRICT_FSETCC:
1033   case ISD::STRICT_FSETCCS:
1034   case ISD::SETCC:
1035   case ISD::BR_CC: {
1036     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1037                          Node->getOpcode() == ISD::STRICT_FSETCC ? 3 :
1038                          Node->getOpcode() == ISD::STRICT_FSETCCS ? 3 :
1039                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1040     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 :
1041                               Node->getOpcode() == ISD::STRICT_FSETCC ? 1 :
1042                               Node->getOpcode() == ISD::STRICT_FSETCCS ? 1 : 0;
1043     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1044     ISD::CondCode CCCode =
1045         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1046     Action = TLI.getCondCodeAction(CCCode, OpVT);
1047     if (Action == TargetLowering::Legal) {
1048       if (Node->getOpcode() == ISD::SELECT_CC)
1049         Action = TLI.getOperationAction(Node->getOpcode(),
1050                                         Node->getValueType(0));
1051       else
1052         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1053     }
1054     break;
1055   }
1056   case ISD::LOAD:
1057   case ISD::STORE:
1058     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1059     // STORE expects the unlegalized operand in some cases.
1060     SimpleFinishLegalizing = false;
1061     break;
1062   case ISD::CALLSEQ_START:
1063   case ISD::CALLSEQ_END:
1064     // FIXME: This shouldn't be necessary.  These nodes have special properties
1065     // dealing with the recursive nature of legalization.  Removing this
1066     // special case should be done as part of making LegalizeDAG non-recursive.
1067     SimpleFinishLegalizing = false;
1068     break;
1069   case ISD::EXTRACT_ELEMENT:
1070   case ISD::FLT_ROUNDS_:
1071   case ISD::MERGE_VALUES:
1072   case ISD::EH_RETURN:
1073   case ISD::FRAME_TO_ARGS_OFFSET:
1074   case ISD::EH_DWARF_CFA:
1075   case ISD::EH_SJLJ_SETJMP:
1076   case ISD::EH_SJLJ_LONGJMP:
1077   case ISD::EH_SJLJ_SETUP_DISPATCH:
1078     // These operations lie about being legal: when they claim to be legal,
1079     // they should actually be expanded.
1080     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1081     if (Action == TargetLowering::Legal)
1082       Action = TargetLowering::Expand;
1083     break;
1084   case ISD::INIT_TRAMPOLINE:
1085   case ISD::ADJUST_TRAMPOLINE:
1086   case ISD::FRAMEADDR:
1087   case ISD::RETURNADDR:
1088   case ISD::ADDROFRETURNADDR:
1089   case ISD::SPONENTRY:
1090     // These operations lie about being legal: when they claim to be legal,
1091     // they should actually be custom-lowered.
1092     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1093     if (Action == TargetLowering::Legal)
1094       Action = TargetLowering::Custom;
1095     break;
1096   case ISD::READCYCLECOUNTER:
1097     // READCYCLECOUNTER returns an i64, even if type legalization might have
1098     // expanded that to several smaller types.
1099     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1100     break;
1101   case ISD::READ_REGISTER:
1102   case ISD::WRITE_REGISTER:
1103     // Named register is legal in the DAG, but blocked by register name
1104     // selection if not implemented by target (to chose the correct register)
1105     // They'll be converted to Copy(To/From)Reg.
1106     Action = TargetLowering::Legal;
1107     break;
1108   case ISD::DEBUGTRAP:
1109     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1110     if (Action == TargetLowering::Expand) {
1111       // replace ISD::DEBUGTRAP with ISD::TRAP
1112       SDValue NewVal;
1113       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1114                            Node->getOperand(0));
1115       ReplaceNode(Node, NewVal.getNode());
1116       LegalizeOp(NewVal.getNode());
1117       return;
1118     }
1119     break;
1120   case ISD::SADDSAT:
1121   case ISD::UADDSAT:
1122   case ISD::SSUBSAT:
1123   case ISD::USUBSAT:
1124   case ISD::SSHLSAT:
1125   case ISD::USHLSAT: {
1126     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1127     break;
1128   }
1129   case ISD::SMULFIX:
1130   case ISD::SMULFIXSAT:
1131   case ISD::UMULFIX:
1132   case ISD::UMULFIXSAT:
1133   case ISD::SDIVFIX:
1134   case ISD::SDIVFIXSAT:
1135   case ISD::UDIVFIX:
1136   case ISD::UDIVFIXSAT: {
1137     unsigned Scale = Node->getConstantOperandVal(2);
1138     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1139                                               Node->getValueType(0), Scale);
1140     break;
1141   }
1142   case ISD::MSCATTER:
1143     Action = TLI.getOperationAction(Node->getOpcode(),
1144                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1145     break;
1146   case ISD::MSTORE:
1147     Action = TLI.getOperationAction(Node->getOpcode(),
1148                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1149     break;
1150   case ISD::VECREDUCE_FADD:
1151   case ISD::VECREDUCE_FMUL:
1152   case ISD::VECREDUCE_ADD:
1153   case ISD::VECREDUCE_MUL:
1154   case ISD::VECREDUCE_AND:
1155   case ISD::VECREDUCE_OR:
1156   case ISD::VECREDUCE_XOR:
1157   case ISD::VECREDUCE_SMAX:
1158   case ISD::VECREDUCE_SMIN:
1159   case ISD::VECREDUCE_UMAX:
1160   case ISD::VECREDUCE_UMIN:
1161   case ISD::VECREDUCE_FMAX:
1162   case ISD::VECREDUCE_FMIN:
1163     Action = TLI.getOperationAction(
1164         Node->getOpcode(), Node->getOperand(0).getValueType());
1165     break;
1166   default:
1167     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1168       Action = TargetLowering::Legal;
1169     } else {
1170       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1171     }
1172     break;
1173   }
1174 
1175   if (SimpleFinishLegalizing) {
1176     SDNode *NewNode = Node;
1177     switch (Node->getOpcode()) {
1178     default: break;
1179     case ISD::SHL:
1180     case ISD::SRL:
1181     case ISD::SRA:
1182     case ISD::ROTL:
1183     case ISD::ROTR: {
1184       // Legalizing shifts/rotates requires adjusting the shift amount
1185       // to the appropriate width.
1186       SDValue Op0 = Node->getOperand(0);
1187       SDValue Op1 = Node->getOperand(1);
1188       if (!Op1.getValueType().isVector()) {
1189         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1190         // The getShiftAmountOperand() may create a new operand node or
1191         // return the existing one. If new operand is created we need
1192         // to update the parent node.
1193         // Do not try to legalize SAO here! It will be automatically legalized
1194         // in the next round.
1195         if (SAO != Op1)
1196           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1197       }
1198     }
1199     break;
1200     case ISD::FSHL:
1201     case ISD::FSHR:
1202     case ISD::SRL_PARTS:
1203     case ISD::SRA_PARTS:
1204     case ISD::SHL_PARTS: {
1205       // Legalizing shifts/rotates requires adjusting the shift amount
1206       // to the appropriate width.
1207       SDValue Op0 = Node->getOperand(0);
1208       SDValue Op1 = Node->getOperand(1);
1209       SDValue Op2 = Node->getOperand(2);
1210       if (!Op2.getValueType().isVector()) {
1211         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1212         // The getShiftAmountOperand() may create a new operand node or
1213         // return the existing one. If new operand is created we need
1214         // to update the parent node.
1215         if (SAO != Op2)
1216           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1217       }
1218       break;
1219     }
1220     }
1221 
1222     if (NewNode != Node) {
1223       ReplaceNode(Node, NewNode);
1224       Node = NewNode;
1225     }
1226     switch (Action) {
1227     case TargetLowering::Legal:
1228       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1229       return;
1230     case TargetLowering::Custom:
1231       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1232       // FIXME: The handling for custom lowering with multiple results is
1233       // a complete mess.
1234       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1235         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1236           return;
1237 
1238         if (Node->getNumValues() == 1) {
1239           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1240           // We can just directly replace this node with the lowered value.
1241           ReplaceNode(SDValue(Node, 0), Res);
1242           return;
1243         }
1244 
1245         SmallVector<SDValue, 8> ResultVals;
1246         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1247           ResultVals.push_back(Res.getValue(i));
1248         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1249         ReplaceNode(Node, ResultVals.data());
1250         return;
1251       }
1252       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1253       LLVM_FALLTHROUGH;
1254     case TargetLowering::Expand:
1255       if (ExpandNode(Node))
1256         return;
1257       LLVM_FALLTHROUGH;
1258     case TargetLowering::LibCall:
1259       ConvertNodeToLibcall(Node);
1260       return;
1261     case TargetLowering::Promote:
1262       PromoteNode(Node);
1263       return;
1264     }
1265   }
1266 
1267   switch (Node->getOpcode()) {
1268   default:
1269 #ifndef NDEBUG
1270     dbgs() << "NODE: ";
1271     Node->dump( &DAG);
1272     dbgs() << "\n";
1273 #endif
1274     llvm_unreachable("Do not know how to legalize this operator!");
1275 
1276   case ISD::CALLSEQ_START:
1277   case ISD::CALLSEQ_END:
1278     break;
1279   case ISD::LOAD:
1280     return LegalizeLoadOps(Node);
1281   case ISD::STORE:
1282     return LegalizeStoreOps(Node);
1283   }
1284 }
1285 
1286 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1287   SDValue Vec = Op.getOperand(0);
1288   SDValue Idx = Op.getOperand(1);
1289   SDLoc dl(Op);
1290 
1291   // Before we generate a new store to a temporary stack slot, see if there is
1292   // already one that we can use. There often is because when we scalarize
1293   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1294   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1295   // the vector. If all are expanded here, we don't want one store per vector
1296   // element.
1297 
1298   // Caches for hasPredecessorHelper
1299   SmallPtrSet<const SDNode *, 32> Visited;
1300   SmallVector<const SDNode *, 16> Worklist;
1301   Visited.insert(Op.getNode());
1302   Worklist.push_back(Idx.getNode());
1303   SDValue StackPtr, Ch;
1304   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1305        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1306     SDNode *User = *UI;
1307     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1308       if (ST->isIndexed() || ST->isTruncatingStore() ||
1309           ST->getValue() != Vec)
1310         continue;
1311 
1312       // Make sure that nothing else could have stored into the destination of
1313       // this store.
1314       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1315         continue;
1316 
1317       // If the index is dependent on the store we will introduce a cycle when
1318       // creating the load (the load uses the index, and by replacing the chain
1319       // we will make the index dependent on the load). Also, the store might be
1320       // dependent on the extractelement and introduce a cycle when creating
1321       // the load.
1322       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1323           ST->hasPredecessor(Op.getNode()))
1324         continue;
1325 
1326       StackPtr = ST->getBasePtr();
1327       Ch = SDValue(ST, 0);
1328       break;
1329     }
1330   }
1331 
1332   EVT VecVT = Vec.getValueType();
1333 
1334   if (!Ch.getNode()) {
1335     // Store the value to a temporary stack slot, then LOAD the returned part.
1336     StackPtr = DAG.CreateStackTemporary(VecVT);
1337     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1338                       MachinePointerInfo());
1339   }
1340 
1341   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1342 
1343   SDValue NewLoad;
1344 
1345   if (Op.getValueType().isVector())
1346     NewLoad =
1347         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1348   else
1349     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1350                              MachinePointerInfo(),
1351                              VecVT.getVectorElementType());
1352 
1353   // Replace the chain going out of the store, by the one out of the load.
1354   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1355 
1356   // We introduced a cycle though, so update the loads operands, making sure
1357   // to use the original store's chain as an incoming chain.
1358   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1359                                           NewLoad->op_end());
1360   NewLoadOperands[0] = Ch;
1361   NewLoad =
1362       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1363   return NewLoad;
1364 }
1365 
1366 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1367   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1368 
1369   SDValue Vec  = Op.getOperand(0);
1370   SDValue Part = Op.getOperand(1);
1371   SDValue Idx  = Op.getOperand(2);
1372   SDLoc dl(Op);
1373 
1374   // Store the value to a temporary stack slot, then LOAD the returned part.
1375   EVT VecVT = Vec.getValueType();
1376   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1377   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1378   MachinePointerInfo PtrInfo =
1379       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1380 
1381   // First store the whole vector.
1382   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1383 
1384   // Then store the inserted part.
1385   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1386 
1387   // Store the subvector.
1388   Ch = DAG.getStore(
1389       Ch, dl, Part, SubStackPtr,
1390       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()));
1391 
1392   // Finally, load the updated vector.
1393   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1394 }
1395 
1396 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1397   assert((Node->getOpcode() == ISD::BUILD_VECTOR ||
1398           Node->getOpcode() == ISD::CONCAT_VECTORS) &&
1399          "Unexpected opcode!");
1400 
1401   // We can't handle this case efficiently.  Allocate a sufficiently
1402   // aligned object on the stack, store each operand into it, then load
1403   // the result as a vector.
1404   // Create the stack frame object.
1405   EVT VT = Node->getValueType(0);
1406   EVT MemVT = isa<BuildVectorSDNode>(Node) ? VT.getVectorElementType()
1407                                            : Node->getOperand(0).getValueType();
1408   SDLoc dl(Node);
1409   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1410   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1411   MachinePointerInfo PtrInfo =
1412       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1413 
1414   // Emit a store of each element to the stack slot.
1415   SmallVector<SDValue, 8> Stores;
1416   unsigned TypeByteSize = MemVT.getSizeInBits() / 8;
1417   assert(TypeByteSize > 0 && "Vector element type too small for stack store!");
1418 
1419   // If the destination vector element type of a BUILD_VECTOR is narrower than
1420   // the source element type, only store the bits necessary.
1421   bool Truncate = isa<BuildVectorSDNode>(Node) &&
1422                   MemVT.bitsLT(Node->getOperand(0).getValueType());
1423 
1424   // Store (in the right endianness) the elements to memory.
1425   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1426     // Ignore undef elements.
1427     if (Node->getOperand(i).isUndef()) continue;
1428 
1429     unsigned Offset = TypeByteSize*i;
1430 
1431     SDValue Idx = DAG.getMemBasePlusOffset(FIPtr, TypeSize::Fixed(Offset), dl);
1432 
1433     if (Truncate)
1434       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1435                                          Node->getOperand(i), Idx,
1436                                          PtrInfo.getWithOffset(Offset), MemVT));
1437     else
1438       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1439                                     Idx, PtrInfo.getWithOffset(Offset)));
1440   }
1441 
1442   SDValue StoreChain;
1443   if (!Stores.empty())    // Not all undef elements?
1444     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1445   else
1446     StoreChain = DAG.getEntryNode();
1447 
1448   // Result is a load from the stack slot.
1449   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1450 }
1451 
1452 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1453 /// containing the sign bit if the target has no integer value capable of
1454 /// holding all bits of the floating-point value.
1455 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1456                                              const SDLoc &DL,
1457                                              SDValue Value) const {
1458   EVT FloatVT = Value.getValueType();
1459   unsigned NumBits = FloatVT.getSizeInBits();
1460   State.FloatVT = FloatVT;
1461   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1462   // Convert to an integer of the same size.
1463   if (TLI.isTypeLegal(IVT)) {
1464     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1465     State.SignMask = APInt::getSignMask(NumBits);
1466     State.SignBit = NumBits - 1;
1467     return;
1468   }
1469 
1470   auto &DataLayout = DAG.getDataLayout();
1471   // Store the float to memory, then load the sign part out as an integer.
1472   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1473   // First create a temporary that is aligned for both the load and store.
1474   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1475   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1476   // Then store the float to it.
1477   State.FloatPtr = StackPtr;
1478   MachineFunction &MF = DAG.getMachineFunction();
1479   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1480   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1481                              State.FloatPointerInfo);
1482 
1483   SDValue IntPtr;
1484   if (DataLayout.isBigEndian()) {
1485     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1486     // Load out a legal integer with the same sign bit as the float.
1487     IntPtr = StackPtr;
1488     State.IntPointerInfo = State.FloatPointerInfo;
1489   } else {
1490     // Advance the pointer so that the loaded byte will contain the sign bit.
1491     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1492     IntPtr =
1493         DAG.getMemBasePlusOffset(StackPtr, TypeSize::Fixed(ByteOffset), DL);
1494     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1495                                                              ByteOffset);
1496   }
1497 
1498   State.IntPtr = IntPtr;
1499   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1500                                   State.IntPointerInfo, MVT::i8);
1501   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1502   State.SignBit = 7;
1503 }
1504 
1505 /// Replace the integer value produced by getSignAsIntValue() with a new value
1506 /// and cast the result back to a floating-point type.
1507 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1508                                               const SDLoc &DL,
1509                                               SDValue NewIntValue) const {
1510   if (!State.Chain)
1511     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1512 
1513   // Override the part containing the sign bit in the value stored on the stack.
1514   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1515                                     State.IntPointerInfo, MVT::i8);
1516   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1517                      State.FloatPointerInfo);
1518 }
1519 
1520 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1521   SDLoc DL(Node);
1522   SDValue Mag = Node->getOperand(0);
1523   SDValue Sign = Node->getOperand(1);
1524 
1525   // Get sign bit into an integer value.
1526   FloatSignAsInt SignAsInt;
1527   getSignAsIntValue(SignAsInt, DL, Sign);
1528 
1529   EVT IntVT = SignAsInt.IntValue.getValueType();
1530   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1531   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1532                                 SignMask);
1533 
1534   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1535   EVT FloatVT = Mag.getValueType();
1536   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1537       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1538     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1539     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1540     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1541                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1542     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1543   }
1544 
1545   // Transform Mag value to integer, and clear the sign bit.
1546   FloatSignAsInt MagAsInt;
1547   getSignAsIntValue(MagAsInt, DL, Mag);
1548   EVT MagVT = MagAsInt.IntValue.getValueType();
1549   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1550   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1551                                     ClearSignMask);
1552 
1553   // Get the signbit at the right position for MagAsInt.
1554   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1555   EVT ShiftVT = IntVT;
1556   if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1557     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1558     ShiftVT = MagVT;
1559   }
1560   if (ShiftAmount > 0) {
1561     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1562     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1563   } else if (ShiftAmount < 0) {
1564     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1565     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1566   }
1567   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1568     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1569   }
1570 
1571   // Store the part with the modified sign and convert back to float.
1572   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1573   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1574 }
1575 
1576 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1577   SDLoc DL(Node);
1578   SDValue Value = Node->getOperand(0);
1579 
1580   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1581   EVT FloatVT = Value.getValueType();
1582   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1583     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1584     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1585   }
1586 
1587   // Transform value to integer, clear the sign bit and transform back.
1588   FloatSignAsInt ValueAsInt;
1589   getSignAsIntValue(ValueAsInt, DL, Value);
1590   EVT IntVT = ValueAsInt.IntValue.getValueType();
1591   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1592   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1593                                     ClearSignMask);
1594   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1595 }
1596 
1597 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1598                                            SmallVectorImpl<SDValue> &Results) {
1599   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1600   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1601           " not tell us which reg is the stack pointer!");
1602   SDLoc dl(Node);
1603   EVT VT = Node->getValueType(0);
1604   SDValue Tmp1 = SDValue(Node, 0);
1605   SDValue Tmp2 = SDValue(Node, 1);
1606   SDValue Tmp3 = Node->getOperand(2);
1607   SDValue Chain = Tmp1.getOperand(0);
1608 
1609   // Chain the dynamic stack allocation so that it doesn't modify the stack
1610   // pointer when other instructions are using the stack.
1611   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1612 
1613   SDValue Size  = Tmp2.getOperand(1);
1614   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1615   Chain = SP.getValue(1);
1616   Align Alignment = cast<ConstantSDNode>(Tmp3)->getAlignValue();
1617   const TargetFrameLowering *TFL = DAG.getSubtarget().getFrameLowering();
1618   unsigned Opc =
1619     TFL->getStackGrowthDirection() == TargetFrameLowering::StackGrowsUp ?
1620     ISD::ADD : ISD::SUB;
1621 
1622   Align StackAlign = TFL->getStackAlign();
1623   Tmp1 = DAG.getNode(Opc, dl, VT, SP, Size);       // Value
1624   if (Alignment > StackAlign)
1625     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1626                        DAG.getConstant(-Alignment.value(), dl, VT));
1627   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1628 
1629   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1630                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1631 
1632   Results.push_back(Tmp1);
1633   Results.push_back(Tmp2);
1634 }
1635 
1636 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1637 /// target.
1638 ///
1639 /// If the SETCC has been legalized using AND / OR, then the legalized node
1640 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1641 /// will be set to false.
1642 ///
1643 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1644 /// then the values of LHS and RHS will be swapped, CC will be set to the
1645 /// new condition, and NeedInvert will be set to false.
1646 ///
1647 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1648 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1649 /// will be set to true. The caller must invert the result of the SETCC with
1650 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1651 /// of a true/false result.
1652 ///
1653 /// \returns true if the SetCC has been legalized, false if it hasn't.
1654 bool SelectionDAGLegalize::LegalizeSetCCCondCode(
1655     EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC, bool &NeedInvert,
1656     const SDLoc &dl, SDValue &Chain, bool IsSignaling) {
1657   MVT OpVT = LHS.getSimpleValueType();
1658   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1659   NeedInvert = false;
1660   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1661   default: llvm_unreachable("Unknown condition code action!");
1662   case TargetLowering::Legal:
1663     // Nothing to do.
1664     break;
1665   case TargetLowering::Expand: {
1666     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1667     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1668       std::swap(LHS, RHS);
1669       CC = DAG.getCondCode(InvCC);
1670       return true;
1671     }
1672     // Swapping operands didn't work. Try inverting the condition.
1673     bool NeedSwap = false;
1674     InvCC = getSetCCInverse(CCCode, OpVT);
1675     if (!TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1676       // If inverting the condition is not enough, try swapping operands
1677       // on top of it.
1678       InvCC = ISD::getSetCCSwappedOperands(InvCC);
1679       NeedSwap = true;
1680     }
1681     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1682       CC = DAG.getCondCode(InvCC);
1683       NeedInvert = true;
1684       if (NeedSwap)
1685         std::swap(LHS, RHS);
1686       return true;
1687     }
1688 
1689     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1690     unsigned Opc = 0;
1691     switch (CCCode) {
1692     default: llvm_unreachable("Don't know how to expand this condition!");
1693     case ISD::SETO:
1694         assert(TLI.isCondCodeLegal(ISD::SETOEQ, OpVT)
1695             && "If SETO is expanded, SETOEQ must be legal!");
1696         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1697     case ISD::SETUO:
1698         assert(TLI.isCondCodeLegal(ISD::SETUNE, OpVT)
1699             && "If SETUO is expanded, SETUNE must be legal!");
1700         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1701     case ISD::SETOEQ:
1702     case ISD::SETOGT:
1703     case ISD::SETOGE:
1704     case ISD::SETOLT:
1705     case ISD::SETOLE:
1706     case ISD::SETONE:
1707     case ISD::SETUEQ:
1708     case ISD::SETUNE:
1709     case ISD::SETUGT:
1710     case ISD::SETUGE:
1711     case ISD::SETULT:
1712     case ISD::SETULE:
1713         // If we are floating point, assign and break, otherwise fall through.
1714         if (!OpVT.isInteger()) {
1715           // We can use the 4th bit to tell if we are the unordered
1716           // or ordered version of the opcode.
1717           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1718           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1719           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1720           break;
1721         }
1722         // Fallthrough if we are unsigned integer.
1723         LLVM_FALLTHROUGH;
1724     case ISD::SETLE:
1725     case ISD::SETGT:
1726     case ISD::SETGE:
1727     case ISD::SETLT:
1728     case ISD::SETNE:
1729     case ISD::SETEQ:
1730       // If all combinations of inverting the condition and swapping operands
1731       // didn't work then we have no means to expand the condition.
1732       llvm_unreachable("Don't know how to expand this condition!");
1733     }
1734 
1735     SDValue SetCC1, SetCC2;
1736     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1737       // If we aren't the ordered or unorder operation,
1738       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1739       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1, SDNodeFlags(), Chain,
1740                             IsSignaling);
1741       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2, SDNodeFlags(), Chain,
1742                             IsSignaling);
1743     } else {
1744       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1745       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1, SDNodeFlags(), Chain,
1746                             IsSignaling);
1747       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2, SDNodeFlags(), Chain,
1748                             IsSignaling);
1749     }
1750     if (Chain)
1751       Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, SetCC1.getValue(1),
1752                           SetCC2.getValue(1));
1753     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1754     RHS = SDValue();
1755     CC  = SDValue();
1756     return true;
1757   }
1758   }
1759   return false;
1760 }
1761 
1762 /// Emit a store/load combination to the stack.  This stores
1763 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1764 /// a load from the stack slot to DestVT, extending it if needed.
1765 /// The resultant code need not be legal.
1766 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1767                                                EVT DestVT, const SDLoc &dl) {
1768   return EmitStackConvert(SrcOp, SlotVT, DestVT, dl, DAG.getEntryNode());
1769 }
1770 
1771 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1772                                                EVT DestVT, const SDLoc &dl,
1773                                                SDValue Chain) {
1774   // Create the stack frame object.
1775   Align SrcAlign = DAG.getDataLayout().getPrefTypeAlign(
1776       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1777   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT.getStoreSize(), SrcAlign);
1778 
1779   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1780   int SPFI = StackPtrFI->getIndex();
1781   MachinePointerInfo PtrInfo =
1782       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1783 
1784   unsigned SrcSize = SrcOp.getValueSizeInBits();
1785   unsigned SlotSize = SlotVT.getSizeInBits();
1786   unsigned DestSize = DestVT.getSizeInBits();
1787   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1788   Align DestAlign = DAG.getDataLayout().getPrefTypeAlign(DestType);
1789 
1790   // Emit a store to the stack slot.  Use a truncstore if the input value is
1791   // later than DestVT.
1792   SDValue Store;
1793 
1794   if (SrcSize > SlotSize)
1795     Store = DAG.getTruncStore(Chain, dl, SrcOp, FIPtr, PtrInfo,
1796                               SlotVT, SrcAlign);
1797   else {
1798     assert(SrcSize == SlotSize && "Invalid store");
1799     Store =
1800         DAG.getStore(Chain, dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1801   }
1802 
1803   // Result is a load from the stack slot.
1804   if (SlotSize == DestSize)
1805     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1806 
1807   assert(SlotSize < DestSize && "Unknown extension!");
1808   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1809                         DestAlign);
1810 }
1811 
1812 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1813   SDLoc dl(Node);
1814   // Create a vector sized/aligned stack slot, store the value to element #0,
1815   // then load the whole vector back out.
1816   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1817 
1818   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1819   int SPFI = StackPtrFI->getIndex();
1820 
1821   SDValue Ch = DAG.getTruncStore(
1822       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1823       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1824       Node->getValueType(0).getVectorElementType());
1825   return DAG.getLoad(
1826       Node->getValueType(0), dl, Ch, StackPtr,
1827       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1828 }
1829 
1830 static bool
1831 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1832                      const TargetLowering &TLI, SDValue &Res) {
1833   unsigned NumElems = Node->getNumOperands();
1834   SDLoc dl(Node);
1835   EVT VT = Node->getValueType(0);
1836 
1837   // Try to group the scalars into pairs, shuffle the pairs together, then
1838   // shuffle the pairs of pairs together, etc. until the vector has
1839   // been built. This will work only if all of the necessary shuffle masks
1840   // are legal.
1841 
1842   // We do this in two phases; first to check the legality of the shuffles,
1843   // and next, assuming that all shuffles are legal, to create the new nodes.
1844   for (int Phase = 0; Phase < 2; ++Phase) {
1845     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1846                                                               NewIntermedVals;
1847     for (unsigned i = 0; i < NumElems; ++i) {
1848       SDValue V = Node->getOperand(i);
1849       if (V.isUndef())
1850         continue;
1851 
1852       SDValue Vec;
1853       if (Phase)
1854         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1855       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1856     }
1857 
1858     while (IntermedVals.size() > 2) {
1859       NewIntermedVals.clear();
1860       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1861         // This vector and the next vector are shuffled together (simply to
1862         // append the one to the other).
1863         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1864 
1865         SmallVector<int, 16> FinalIndices;
1866         FinalIndices.reserve(IntermedVals[i].second.size() +
1867                              IntermedVals[i+1].second.size());
1868 
1869         int k = 0;
1870         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1871              ++j, ++k) {
1872           ShuffleVec[k] = j;
1873           FinalIndices.push_back(IntermedVals[i].second[j]);
1874         }
1875         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1876              ++j, ++k) {
1877           ShuffleVec[k] = NumElems + j;
1878           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1879         }
1880 
1881         SDValue Shuffle;
1882         if (Phase)
1883           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1884                                          IntermedVals[i+1].first,
1885                                          ShuffleVec);
1886         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1887           return false;
1888         NewIntermedVals.push_back(
1889             std::make_pair(Shuffle, std::move(FinalIndices)));
1890       }
1891 
1892       // If we had an odd number of defined values, then append the last
1893       // element to the array of new vectors.
1894       if ((IntermedVals.size() & 1) != 0)
1895         NewIntermedVals.push_back(IntermedVals.back());
1896 
1897       IntermedVals.swap(NewIntermedVals);
1898     }
1899 
1900     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1901            "Invalid number of intermediate vectors");
1902     SDValue Vec1 = IntermedVals[0].first;
1903     SDValue Vec2;
1904     if (IntermedVals.size() > 1)
1905       Vec2 = IntermedVals[1].first;
1906     else if (Phase)
1907       Vec2 = DAG.getUNDEF(VT);
1908 
1909     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1910     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1911       ShuffleVec[IntermedVals[0].second[i]] = i;
1912     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1913       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1914 
1915     if (Phase)
1916       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1917     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1918       return false;
1919   }
1920 
1921   return true;
1922 }
1923 
1924 /// Expand a BUILD_VECTOR node on targets that don't
1925 /// support the operation, but do support the resultant vector type.
1926 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1927   unsigned NumElems = Node->getNumOperands();
1928   SDValue Value1, Value2;
1929   SDLoc dl(Node);
1930   EVT VT = Node->getValueType(0);
1931   EVT OpVT = Node->getOperand(0).getValueType();
1932   EVT EltVT = VT.getVectorElementType();
1933 
1934   // If the only non-undef value is the low element, turn this into a
1935   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1936   bool isOnlyLowElement = true;
1937   bool MoreThanTwoValues = false;
1938   bool isConstant = true;
1939   for (unsigned i = 0; i < NumElems; ++i) {
1940     SDValue V = Node->getOperand(i);
1941     if (V.isUndef())
1942       continue;
1943     if (i > 0)
1944       isOnlyLowElement = false;
1945     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1946       isConstant = false;
1947 
1948     if (!Value1.getNode()) {
1949       Value1 = V;
1950     } else if (!Value2.getNode()) {
1951       if (V != Value1)
1952         Value2 = V;
1953     } else if (V != Value1 && V != Value2) {
1954       MoreThanTwoValues = true;
1955     }
1956   }
1957 
1958   if (!Value1.getNode())
1959     return DAG.getUNDEF(VT);
1960 
1961   if (isOnlyLowElement)
1962     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1963 
1964   // If all elements are constants, create a load from the constant pool.
1965   if (isConstant) {
1966     SmallVector<Constant*, 16> CV;
1967     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1968       if (ConstantFPSDNode *V =
1969           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1970         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1971       } else if (ConstantSDNode *V =
1972                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1973         if (OpVT==EltVT)
1974           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1975         else {
1976           // If OpVT and EltVT don't match, EltVT is not legal and the
1977           // element values have been promoted/truncated earlier.  Undo this;
1978           // we don't want a v16i8 to become a v16i32 for example.
1979           const ConstantInt *CI = V->getConstantIntValue();
1980           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1981                                         CI->getZExtValue()));
1982         }
1983       } else {
1984         assert(Node->getOperand(i).isUndef());
1985         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1986         CV.push_back(UndefValue::get(OpNTy));
1987       }
1988     }
1989     Constant *CP = ConstantVector::get(CV);
1990     SDValue CPIdx =
1991         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1992     Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
1993     return DAG.getLoad(
1994         VT, dl, DAG.getEntryNode(), CPIdx,
1995         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1996         Alignment);
1997   }
1998 
1999   SmallSet<SDValue, 16> DefinedValues;
2000   for (unsigned i = 0; i < NumElems; ++i) {
2001     if (Node->getOperand(i).isUndef())
2002       continue;
2003     DefinedValues.insert(Node->getOperand(i));
2004   }
2005 
2006   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
2007     if (!MoreThanTwoValues) {
2008       SmallVector<int, 8> ShuffleVec(NumElems, -1);
2009       for (unsigned i = 0; i < NumElems; ++i) {
2010         SDValue V = Node->getOperand(i);
2011         if (V.isUndef())
2012           continue;
2013         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
2014       }
2015       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
2016         // Get the splatted value into the low element of a vector register.
2017         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
2018         SDValue Vec2;
2019         if (Value2.getNode())
2020           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
2021         else
2022           Vec2 = DAG.getUNDEF(VT);
2023 
2024         // Return shuffle(LowValVec, undef, <0,0,0,0>)
2025         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
2026       }
2027     } else {
2028       SDValue Res;
2029       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
2030         return Res;
2031     }
2032   }
2033 
2034   // Otherwise, we can't handle this case efficiently.
2035   return ExpandVectorBuildThroughStack(Node);
2036 }
2037 
2038 SDValue SelectionDAGLegalize::ExpandSPLAT_VECTOR(SDNode *Node) {
2039   SDLoc DL(Node);
2040   EVT VT = Node->getValueType(0);
2041   SDValue SplatVal = Node->getOperand(0);
2042 
2043   return DAG.getSplatBuildVector(VT, DL, SplatVal);
2044 }
2045 
2046 // Expand a node into a call to a libcall.  If the result value
2047 // does not fit into a register, return the lo part and set the hi part to the
2048 // by-reg argument.  If it does fit into a single register, return the result
2049 // and leave the Hi part unset.
2050 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
2051                                             bool isSigned) {
2052   TargetLowering::ArgListTy Args;
2053   TargetLowering::ArgListEntry Entry;
2054   for (const SDValue &Op : Node->op_values()) {
2055     EVT ArgVT = Op.getValueType();
2056     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2057     Entry.Node = Op;
2058     Entry.Ty = ArgTy;
2059     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2060     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2061     Args.push_back(Entry);
2062   }
2063   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2064                                          TLI.getPointerTy(DAG.getDataLayout()));
2065 
2066   EVT RetVT = Node->getValueType(0);
2067   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2068 
2069   // By default, the input chain to this libcall is the entry node of the
2070   // function. If the libcall is going to be emitted as a tail call then
2071   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2072   // node which is being folded has a non-entry input chain.
2073   SDValue InChain = DAG.getEntryNode();
2074 
2075   // isTailCall may be true since the callee does not reference caller stack
2076   // frame. Check if it's in the right position and that the return types match.
2077   SDValue TCChain = InChain;
2078   const Function &F = DAG.getMachineFunction().getFunction();
2079   bool isTailCall =
2080       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2081       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2082   if (isTailCall)
2083     InChain = TCChain;
2084 
2085   TargetLowering::CallLoweringInfo CLI(DAG);
2086   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2087   CLI.setDebugLoc(SDLoc(Node))
2088       .setChain(InChain)
2089       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2090                     std::move(Args))
2091       .setTailCall(isTailCall)
2092       .setSExtResult(signExtend)
2093       .setZExtResult(!signExtend)
2094       .setIsPostTypeLegalization(true);
2095 
2096   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2097 
2098   if (!CallInfo.second.getNode()) {
2099     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump(&DAG));
2100     // It's a tailcall, return the chain (which is the DAG root).
2101     return DAG.getRoot();
2102   }
2103 
2104   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump(&DAG));
2105   return CallInfo.first;
2106 }
2107 
2108 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2109                                            RTLIB::Libcall Call_F32,
2110                                            RTLIB::Libcall Call_F64,
2111                                            RTLIB::Libcall Call_F80,
2112                                            RTLIB::Libcall Call_F128,
2113                                            RTLIB::Libcall Call_PPCF128,
2114                                            SmallVectorImpl<SDValue> &Results) {
2115   RTLIB::Libcall LC;
2116   switch (Node->getSimpleValueType(0).SimpleTy) {
2117   default: llvm_unreachable("Unexpected request for libcall!");
2118   case MVT::f32: LC = Call_F32; break;
2119   case MVT::f64: LC = Call_F64; break;
2120   case MVT::f80: LC = Call_F80; break;
2121   case MVT::f128: LC = Call_F128; break;
2122   case MVT::ppcf128: LC = Call_PPCF128; break;
2123   }
2124 
2125   if (Node->isStrictFPOpcode()) {
2126     EVT RetVT = Node->getValueType(0);
2127     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
2128     TargetLowering::MakeLibCallOptions CallOptions;
2129     // FIXME: This doesn't support tail calls.
2130     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2131                                                       Ops, CallOptions,
2132                                                       SDLoc(Node),
2133                                                       Node->getOperand(0));
2134     Results.push_back(Tmp.first);
2135     Results.push_back(Tmp.second);
2136   } else {
2137     SDValue Tmp = ExpandLibCall(LC, Node, false);
2138     Results.push_back(Tmp);
2139   }
2140 }
2141 
2142 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2143                                                RTLIB::Libcall Call_I8,
2144                                                RTLIB::Libcall Call_I16,
2145                                                RTLIB::Libcall Call_I32,
2146                                                RTLIB::Libcall Call_I64,
2147                                                RTLIB::Libcall Call_I128) {
2148   RTLIB::Libcall LC;
2149   switch (Node->getSimpleValueType(0).SimpleTy) {
2150   default: llvm_unreachable("Unexpected request for libcall!");
2151   case MVT::i8:   LC = Call_I8; break;
2152   case MVT::i16:  LC = Call_I16; break;
2153   case MVT::i32:  LC = Call_I32; break;
2154   case MVT::i64:  LC = Call_I64; break;
2155   case MVT::i128: LC = Call_I128; break;
2156   }
2157   return ExpandLibCall(LC, Node, isSigned);
2158 }
2159 
2160 /// Expand the node to a libcall based on first argument type (for instance
2161 /// lround and its variant).
2162 void SelectionDAGLegalize::ExpandArgFPLibCall(SDNode* Node,
2163                                             RTLIB::Libcall Call_F32,
2164                                             RTLIB::Libcall Call_F64,
2165                                             RTLIB::Libcall Call_F80,
2166                                             RTLIB::Libcall Call_F128,
2167                                             RTLIB::Libcall Call_PPCF128,
2168                                             SmallVectorImpl<SDValue> &Results) {
2169   EVT InVT = Node->getOperand(Node->isStrictFPOpcode() ? 1 : 0).getValueType();
2170 
2171   RTLIB::Libcall LC;
2172   switch (InVT.getSimpleVT().SimpleTy) {
2173   default: llvm_unreachable("Unexpected request for libcall!");
2174   case MVT::f32:     LC = Call_F32; break;
2175   case MVT::f64:     LC = Call_F64; break;
2176   case MVT::f80:     LC = Call_F80; break;
2177   case MVT::f128:    LC = Call_F128; break;
2178   case MVT::ppcf128: LC = Call_PPCF128; break;
2179   }
2180 
2181   if (Node->isStrictFPOpcode()) {
2182     EVT RetVT = Node->getValueType(0);
2183     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
2184     TargetLowering::MakeLibCallOptions CallOptions;
2185     // FIXME: This doesn't support tail calls.
2186     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2187                                                       Ops, CallOptions,
2188                                                       SDLoc(Node),
2189                                                       Node->getOperand(0));
2190     Results.push_back(Tmp.first);
2191     Results.push_back(Tmp.second);
2192   } else {
2193     SDValue Tmp = ExpandLibCall(LC, Node, false);
2194     Results.push_back(Tmp);
2195   }
2196 }
2197 
2198 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2199 void
2200 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2201                                           SmallVectorImpl<SDValue> &Results) {
2202   unsigned Opcode = Node->getOpcode();
2203   bool isSigned = Opcode == ISD::SDIVREM;
2204 
2205   RTLIB::Libcall LC;
2206   switch (Node->getSimpleValueType(0).SimpleTy) {
2207   default: llvm_unreachable("Unexpected request for libcall!");
2208   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2209   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2210   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2211   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2212   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2213   }
2214 
2215   // The input chain to this libcall is the entry node of the function.
2216   // Legalizing the call will automatically add the previous call to the
2217   // dependence.
2218   SDValue InChain = DAG.getEntryNode();
2219 
2220   EVT RetVT = Node->getValueType(0);
2221   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2222 
2223   TargetLowering::ArgListTy Args;
2224   TargetLowering::ArgListEntry Entry;
2225   for (const SDValue &Op : Node->op_values()) {
2226     EVT ArgVT = Op.getValueType();
2227     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2228     Entry.Node = Op;
2229     Entry.Ty = ArgTy;
2230     Entry.IsSExt = isSigned;
2231     Entry.IsZExt = !isSigned;
2232     Args.push_back(Entry);
2233   }
2234 
2235   // Also pass the return address of the remainder.
2236   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2237   Entry.Node = FIPtr;
2238   Entry.Ty = RetTy->getPointerTo();
2239   Entry.IsSExt = isSigned;
2240   Entry.IsZExt = !isSigned;
2241   Args.push_back(Entry);
2242 
2243   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2244                                          TLI.getPointerTy(DAG.getDataLayout()));
2245 
2246   SDLoc dl(Node);
2247   TargetLowering::CallLoweringInfo CLI(DAG);
2248   CLI.setDebugLoc(dl)
2249       .setChain(InChain)
2250       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2251                     std::move(Args))
2252       .setSExtResult(isSigned)
2253       .setZExtResult(!isSigned);
2254 
2255   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2256 
2257   // Remainder is loaded back from the stack frame.
2258   SDValue Rem =
2259       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2260   Results.push_back(CallInfo.first);
2261   Results.push_back(Rem);
2262 }
2263 
2264 /// Return true if sincos libcall is available.
2265 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2266   RTLIB::Libcall LC;
2267   switch (Node->getSimpleValueType(0).SimpleTy) {
2268   default: llvm_unreachable("Unexpected request for libcall!");
2269   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2270   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2271   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2272   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2273   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2274   }
2275   return TLI.getLibcallName(LC) != nullptr;
2276 }
2277 
2278 /// Only issue sincos libcall if both sin and cos are needed.
2279 static bool useSinCos(SDNode *Node) {
2280   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2281     ? ISD::FCOS : ISD::FSIN;
2282 
2283   SDValue Op0 = Node->getOperand(0);
2284   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2285        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2286     SDNode *User = *UI;
2287     if (User == Node)
2288       continue;
2289     // The other user might have been turned into sincos already.
2290     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2291       return true;
2292   }
2293   return false;
2294 }
2295 
2296 /// Issue libcalls to sincos to compute sin / cos pairs.
2297 void
2298 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2299                                           SmallVectorImpl<SDValue> &Results) {
2300   RTLIB::Libcall LC;
2301   switch (Node->getSimpleValueType(0).SimpleTy) {
2302   default: llvm_unreachable("Unexpected request for libcall!");
2303   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2304   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2305   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2306   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2307   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2308   }
2309 
2310   // The input chain to this libcall is the entry node of the function.
2311   // Legalizing the call will automatically add the previous call to the
2312   // dependence.
2313   SDValue InChain = DAG.getEntryNode();
2314 
2315   EVT RetVT = Node->getValueType(0);
2316   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2317 
2318   TargetLowering::ArgListTy Args;
2319   TargetLowering::ArgListEntry Entry;
2320 
2321   // Pass the argument.
2322   Entry.Node = Node->getOperand(0);
2323   Entry.Ty = RetTy;
2324   Entry.IsSExt = false;
2325   Entry.IsZExt = false;
2326   Args.push_back(Entry);
2327 
2328   // Pass the return address of sin.
2329   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2330   Entry.Node = SinPtr;
2331   Entry.Ty = RetTy->getPointerTo();
2332   Entry.IsSExt = false;
2333   Entry.IsZExt = false;
2334   Args.push_back(Entry);
2335 
2336   // Also pass the return address of the cos.
2337   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2338   Entry.Node = CosPtr;
2339   Entry.Ty = RetTy->getPointerTo();
2340   Entry.IsSExt = false;
2341   Entry.IsZExt = false;
2342   Args.push_back(Entry);
2343 
2344   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2345                                          TLI.getPointerTy(DAG.getDataLayout()));
2346 
2347   SDLoc dl(Node);
2348   TargetLowering::CallLoweringInfo CLI(DAG);
2349   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2350       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2351       std::move(Args));
2352 
2353   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2354 
2355   Results.push_back(
2356       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2357   Results.push_back(
2358       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2359 }
2360 
2361 /// This function is responsible for legalizing a
2362 /// INT_TO_FP operation of the specified operand when the target requests that
2363 /// we expand it.  At this point, we know that the result and operand types are
2364 /// legal for the target.
2365 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(SDNode *Node,
2366                                                    SDValue &Chain) {
2367   bool isSigned = (Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
2368                    Node->getOpcode() == ISD::SINT_TO_FP);
2369   EVT DestVT = Node->getValueType(0);
2370   SDLoc dl(Node);
2371   unsigned OpNo = Node->isStrictFPOpcode() ? 1 : 0;
2372   SDValue Op0 = Node->getOperand(OpNo);
2373   EVT SrcVT = Op0.getValueType();
2374 
2375   // TODO: Should any fast-math-flags be set for the created nodes?
2376   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2377   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2378     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2379                          "expansion\n");
2380 
2381     // Get the stack frame index of a 8 byte buffer.
2382     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2383 
2384     SDValue Lo = Op0;
2385     // if signed map to unsigned space
2386     if (isSigned) {
2387       // Invert sign bit (signed to unsigned mapping).
2388       Lo = DAG.getNode(ISD::XOR, dl, MVT::i32, Lo,
2389                        DAG.getConstant(0x80000000u, dl, MVT::i32));
2390     }
2391     // Initial hi portion of constructed double.
2392     SDValue Hi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2393 
2394     // If this a big endian target, swap the lo and high data.
2395     if (DAG.getDataLayout().isBigEndian())
2396       std::swap(Lo, Hi);
2397 
2398     SDValue MemChain = DAG.getEntryNode();
2399 
2400     // Store the lo of the constructed double.
2401     SDValue Store1 = DAG.getStore(MemChain, dl, Lo, StackSlot,
2402                                   MachinePointerInfo());
2403     // Store the hi of the constructed double.
2404     SDValue HiPtr = DAG.getMemBasePlusOffset(StackSlot, TypeSize::Fixed(4), dl);
2405     SDValue Store2 =
2406         DAG.getStore(MemChain, dl, Hi, HiPtr, MachinePointerInfo());
2407     MemChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
2408 
2409     // load the constructed double
2410     SDValue Load =
2411         DAG.getLoad(MVT::f64, dl, MemChain, StackSlot, MachinePointerInfo());
2412     // FP constant to bias correct the final result
2413     SDValue Bias = DAG.getConstantFP(isSigned ?
2414                                      BitsToDouble(0x4330000080000000ULL) :
2415                                      BitsToDouble(0x4330000000000000ULL),
2416                                      dl, MVT::f64);
2417     // Subtract the bias and get the final result.
2418     SDValue Sub;
2419     SDValue Result;
2420     if (Node->isStrictFPOpcode()) {
2421       Sub = DAG.getNode(ISD::STRICT_FSUB, dl, {MVT::f64, MVT::Other},
2422                         {Node->getOperand(0), Load, Bias});
2423       Chain = Sub.getValue(1);
2424       if (DestVT != Sub.getValueType()) {
2425         std::pair<SDValue, SDValue> ResultPair;
2426         ResultPair =
2427             DAG.getStrictFPExtendOrRound(Sub, Chain, dl, DestVT);
2428         Result = ResultPair.first;
2429         Chain = ResultPair.second;
2430       }
2431       else
2432         Result = Sub;
2433     } else {
2434       Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2435       Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2436     }
2437     return Result;
2438   }
2439   // Code below here assumes !isSigned without checking again.
2440   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2441 
2442   // TODO: Generalize this for use with other types.
2443   if ((SrcVT == MVT::i32 || SrcVT == MVT::i64) && DestVT == MVT::f32) {
2444     LLVM_DEBUG(dbgs() << "Converting unsigned i32/i64 to f32\n");
2445     // For unsigned conversions, convert them to signed conversions using the
2446     // algorithm from the x86_64 __floatundisf in compiler_rt. That method
2447     // should be valid for i32->f32 as well.
2448 
2449     // TODO: This really should be implemented using a branch rather than a
2450     // select.  We happen to get lucky and machinesink does the right
2451     // thing most of the time.  This would be a good candidate for a
2452     // pseudo-op, or, even better, for whole-function isel.
2453     EVT SetCCVT = getSetCCResultType(SrcVT);
2454 
2455     SDValue SignBitTest = DAG.getSetCC(
2456         dl, SetCCVT, Op0, DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2457 
2458     EVT ShiftVT = TLI.getShiftAmountTy(SrcVT, DAG.getDataLayout());
2459     SDValue ShiftConst = DAG.getConstant(1, dl, ShiftVT);
2460     SDValue Shr = DAG.getNode(ISD::SRL, dl, SrcVT, Op0, ShiftConst);
2461     SDValue AndConst = DAG.getConstant(1, dl, SrcVT);
2462     SDValue And = DAG.getNode(ISD::AND, dl, SrcVT, Op0, AndConst);
2463     SDValue Or = DAG.getNode(ISD::OR, dl, SrcVT, And, Shr);
2464 
2465     SDValue Slow, Fast;
2466     if (Node->isStrictFPOpcode()) {
2467       // In strict mode, we must avoid spurious exceptions, and therefore
2468       // must make sure to only emit a single STRICT_SINT_TO_FP.
2469       SDValue InCvt = DAG.getSelect(dl, SrcVT, SignBitTest, Or, Op0);
2470       Fast = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2471                          { Node->getOperand(0), InCvt });
2472       Slow = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2473                          { Fast.getValue(1), Fast, Fast });
2474       Chain = Slow.getValue(1);
2475       // The STRICT_SINT_TO_FP inherits the exception mode from the
2476       // incoming STRICT_UINT_TO_FP node; the STRICT_FADD node can
2477       // never raise any exception.
2478       SDNodeFlags Flags;
2479       Flags.setNoFPExcept(Node->getFlags().hasNoFPExcept());
2480       Fast->setFlags(Flags);
2481       Flags.setNoFPExcept(true);
2482       Slow->setFlags(Flags);
2483     } else {
2484       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Or);
2485       Slow = DAG.getNode(ISD::FADD, dl, DestVT, SignCvt, SignCvt);
2486       Fast = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2487     }
2488 
2489     return DAG.getSelect(dl, DestVT, SignBitTest, Slow, Fast);
2490   }
2491 
2492   // The following optimization is valid only if every value in SrcVT (when
2493   // treated as signed) is representable in DestVT.  Check that the mantissa
2494   // size of DestVT is >= than the number of bits in SrcVT -1.
2495   assert(APFloat::semanticsPrecision(DAG.EVTToAPFloatSemantics(DestVT)) >=
2496              SrcVT.getSizeInBits() - 1 &&
2497          "Cannot perform lossless SINT_TO_FP!");
2498 
2499   SDValue Tmp1;
2500   if (Node->isStrictFPOpcode()) {
2501     Tmp1 = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2502                        { Node->getOperand(0), Op0 });
2503   } else
2504     Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2505 
2506   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2507                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2508   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2509           Four = DAG.getIntPtrConstant(4, dl);
2510   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2511                                     SignSet, Four, Zero);
2512 
2513   // If the sign bit of the integer is set, the large number will be treated
2514   // as a negative number.  To counteract this, the dynamic code adds an
2515   // offset depending on the data type.
2516   uint64_t FF;
2517   switch (SrcVT.getSimpleVT().SimpleTy) {
2518   default: llvm_unreachable("Unsupported integer type!");
2519   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2520   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2521   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2522   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2523   }
2524   if (DAG.getDataLayout().isLittleEndian())
2525     FF <<= 32;
2526   Constant *FudgeFactor = ConstantInt::get(
2527                                        Type::getInt64Ty(*DAG.getContext()), FF);
2528 
2529   SDValue CPIdx =
2530       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2531   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
2532   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2533   Alignment = commonAlignment(Alignment, 4);
2534   SDValue FudgeInReg;
2535   if (DestVT == MVT::f32)
2536     FudgeInReg = DAG.getLoad(
2537         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2538         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2539         Alignment);
2540   else {
2541     SDValue Load = DAG.getExtLoad(
2542         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2543         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2544         Alignment);
2545     HandleSDNode Handle(Load);
2546     LegalizeOp(Load.getNode());
2547     FudgeInReg = Handle.getValue();
2548   }
2549 
2550   if (Node->isStrictFPOpcode()) {
2551     SDValue Result = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2552                                  { Tmp1.getValue(1), Tmp1, FudgeInReg });
2553     Chain = Result.getValue(1);
2554     return Result;
2555   }
2556 
2557   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2558 }
2559 
2560 /// This function is responsible for legalizing a
2561 /// *INT_TO_FP operation of the specified operand when the target requests that
2562 /// we promote it.  At this point, we know that the result and operand types are
2563 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2564 /// operation that takes a larger input.
2565 void SelectionDAGLegalize::PromoteLegalINT_TO_FP(
2566     SDNode *N, const SDLoc &dl, SmallVectorImpl<SDValue> &Results) {
2567   bool IsStrict = N->isStrictFPOpcode();
2568   bool IsSigned = N->getOpcode() == ISD::SINT_TO_FP ||
2569                   N->getOpcode() == ISD::STRICT_SINT_TO_FP;
2570   EVT DestVT = N->getValueType(0);
2571   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2572   unsigned UIntOp = IsStrict ? ISD::STRICT_UINT_TO_FP : ISD::UINT_TO_FP;
2573   unsigned SIntOp = IsStrict ? ISD::STRICT_SINT_TO_FP : ISD::SINT_TO_FP;
2574 
2575   // First step, figure out the appropriate *INT_TO_FP operation to use.
2576   EVT NewInTy = LegalOp.getValueType();
2577 
2578   unsigned OpToUse = 0;
2579 
2580   // Scan for the appropriate larger type to use.
2581   while (true) {
2582     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2583     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2584 
2585     // If the target supports SINT_TO_FP of this type, use it.
2586     if (TLI.isOperationLegalOrCustom(SIntOp, NewInTy)) {
2587       OpToUse = SIntOp;
2588       break;
2589     }
2590     if (IsSigned)
2591       continue;
2592 
2593     // If the target supports UINT_TO_FP of this type, use it.
2594     if (TLI.isOperationLegalOrCustom(UIntOp, NewInTy)) {
2595       OpToUse = UIntOp;
2596       break;
2597     }
2598 
2599     // Otherwise, try a larger type.
2600   }
2601 
2602   // Okay, we found the operation and type to use.  Zero extend our input to the
2603   // desired type then run the operation on it.
2604   if (IsStrict) {
2605     SDValue Res =
2606         DAG.getNode(OpToUse, dl, {DestVT, MVT::Other},
2607                     {N->getOperand(0),
2608                      DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2609                                  dl, NewInTy, LegalOp)});
2610     Results.push_back(Res);
2611     Results.push_back(Res.getValue(1));
2612     return;
2613   }
2614 
2615   Results.push_back(
2616       DAG.getNode(OpToUse, dl, DestVT,
2617                   DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2618                               dl, NewInTy, LegalOp)));
2619 }
2620 
2621 /// This function is responsible for legalizing a
2622 /// FP_TO_*INT operation of the specified operand when the target requests that
2623 /// we promote it.  At this point, we know that the result and operand types are
2624 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2625 /// operation that returns a larger result.
2626 void SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
2627                                                  SmallVectorImpl<SDValue> &Results) {
2628   bool IsStrict = N->isStrictFPOpcode();
2629   bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT ||
2630                   N->getOpcode() == ISD::STRICT_FP_TO_SINT;
2631   EVT DestVT = N->getValueType(0);
2632   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2633   // First step, figure out the appropriate FP_TO*INT operation to use.
2634   EVT NewOutTy = DestVT;
2635 
2636   unsigned OpToUse = 0;
2637 
2638   // Scan for the appropriate larger type to use.
2639   while (true) {
2640     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2641     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2642 
2643     // A larger signed type can hold all unsigned values of the requested type,
2644     // so using FP_TO_SINT is valid
2645     OpToUse = IsStrict ? ISD::STRICT_FP_TO_SINT : ISD::FP_TO_SINT;
2646     if (TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2647       break;
2648 
2649     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2650     OpToUse = IsStrict ? ISD::STRICT_FP_TO_UINT : ISD::FP_TO_UINT;
2651     if (!IsSigned && TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2652       break;
2653 
2654     // Otherwise, try a larger type.
2655   }
2656 
2657   // Okay, we found the operation and type to use.
2658   SDValue Operation;
2659   if (IsStrict) {
2660     SDVTList VTs = DAG.getVTList(NewOutTy, MVT::Other);
2661     Operation = DAG.getNode(OpToUse, dl, VTs, N->getOperand(0), LegalOp);
2662   } else
2663     Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2664 
2665   // Truncate the result of the extended FP_TO_*INT operation to the desired
2666   // size.
2667   SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2668   Results.push_back(Trunc);
2669   if (IsStrict)
2670     Results.push_back(Operation.getValue(1));
2671 }
2672 
2673 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
2674 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2675   EVT VT = Op.getValueType();
2676   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2677   unsigned Sz = VT.getScalarSizeInBits();
2678 
2679   SDValue Tmp, Tmp2, Tmp3;
2680 
2681   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2682   // and finally the i1 pairs.
2683   // TODO: We can easily support i4/i2 legal types if any target ever does.
2684   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2685     // Create the masks - repeating the pattern every byte.
2686     APInt MaskHi4 = APInt::getSplat(Sz, APInt(8, 0xF0));
2687     APInt MaskHi2 = APInt::getSplat(Sz, APInt(8, 0xCC));
2688     APInt MaskHi1 = APInt::getSplat(Sz, APInt(8, 0xAA));
2689     APInt MaskLo4 = APInt::getSplat(Sz, APInt(8, 0x0F));
2690     APInt MaskLo2 = APInt::getSplat(Sz, APInt(8, 0x33));
2691     APInt MaskLo1 = APInt::getSplat(Sz, APInt(8, 0x55));
2692 
2693     // BSWAP if the type is wider than a single byte.
2694     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2695 
2696     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2697     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2698     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2699     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, SHVT));
2700     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, SHVT));
2701     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2702 
2703     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2704     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2705     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2706     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, SHVT));
2707     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, SHVT));
2708     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2709 
2710     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2711     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2712     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2713     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, SHVT));
2714     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, SHVT));
2715     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2716     return Tmp;
2717   }
2718 
2719   Tmp = DAG.getConstant(0, dl, VT);
2720   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2721     if (I < J)
2722       Tmp2 =
2723           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2724     else
2725       Tmp2 =
2726           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2727 
2728     APInt Shift(Sz, 1);
2729     Shift <<= J;
2730     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2731     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2732   }
2733 
2734   return Tmp;
2735 }
2736 
2737 /// Open code the operations for BSWAP of the specified operation.
2738 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2739   EVT VT = Op.getValueType();
2740   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2741   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2742   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2743   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2744   case MVT::i16:
2745     // Use a rotate by 8. This can be further expanded if necessary.
2746     return DAG.getNode(ISD::ROTL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2747   case MVT::i32:
2748     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2749     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2750     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2751     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2752     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2753                        DAG.getConstant(0xFF0000, dl, VT));
2754     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2755     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2756     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2757     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2758   case MVT::i64:
2759     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2760     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2761     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2762     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2763     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2764     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2765     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2766     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2767     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2768                        DAG.getConstant(255ULL<<48, dl, VT));
2769     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2770                        DAG.getConstant(255ULL<<40, dl, VT));
2771     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2772                        DAG.getConstant(255ULL<<32, dl, VT));
2773     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2774                        DAG.getConstant(255ULL<<24, dl, VT));
2775     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2776                        DAG.getConstant(255ULL<<16, dl, VT));
2777     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2778                        DAG.getConstant(255ULL<<8 , dl, VT));
2779     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2780     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2781     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2782     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2783     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2784     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2785     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2786   }
2787 }
2788 
2789 /// Open code the operations for PARITY of the specified operation.
2790 SDValue SelectionDAGLegalize::ExpandPARITY(SDValue Op, const SDLoc &dl) {
2791   EVT VT = Op.getValueType();
2792   EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2793   unsigned Sz = VT.getScalarSizeInBits();
2794 
2795   // If CTPOP is legal, use it. Otherwise use shifts and xor.
2796   SDValue Result;
2797   if (TLI.isOperationLegal(ISD::CTPOP, VT)) {
2798     Result = DAG.getNode(ISD::CTPOP, dl, VT, Op);
2799   } else {
2800     Result = Op;
2801     for (unsigned i = Log2_32_Ceil(Sz); i != 0;) {
2802       SDValue Shift = DAG.getNode(ISD::SRL, dl, VT, Result,
2803                                   DAG.getConstant(1ULL << (--i), dl, ShVT));
2804       Result = DAG.getNode(ISD::XOR, dl, VT, Result, Shift);
2805     }
2806   }
2807 
2808   return DAG.getNode(ISD::AND, dl, VT, Result, DAG.getConstant(1, dl, VT));
2809 }
2810 
2811 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2812   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2813   SmallVector<SDValue, 8> Results;
2814   SDLoc dl(Node);
2815   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2816   bool NeedInvert;
2817   switch (Node->getOpcode()) {
2818   case ISD::ABS:
2819     if (TLI.expandABS(Node, Tmp1, DAG))
2820       Results.push_back(Tmp1);
2821     break;
2822   case ISD::CTPOP:
2823     if (TLI.expandCTPOP(Node, Tmp1, DAG))
2824       Results.push_back(Tmp1);
2825     break;
2826   case ISD::CTLZ:
2827   case ISD::CTLZ_ZERO_UNDEF:
2828     if (TLI.expandCTLZ(Node, Tmp1, DAG))
2829       Results.push_back(Tmp1);
2830     break;
2831   case ISD::CTTZ:
2832   case ISD::CTTZ_ZERO_UNDEF:
2833     if (TLI.expandCTTZ(Node, Tmp1, DAG))
2834       Results.push_back(Tmp1);
2835     break;
2836   case ISD::BITREVERSE:
2837     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2838     break;
2839   case ISD::BSWAP:
2840     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2841     break;
2842   case ISD::PARITY:
2843     Results.push_back(ExpandPARITY(Node->getOperand(0), dl));
2844     break;
2845   case ISD::FRAMEADDR:
2846   case ISD::RETURNADDR:
2847   case ISD::FRAME_TO_ARGS_OFFSET:
2848     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2849     break;
2850   case ISD::EH_DWARF_CFA: {
2851     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2852                                         TLI.getPointerTy(DAG.getDataLayout()));
2853     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2854                                  CfaArg.getValueType(),
2855                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2856                                              CfaArg.getValueType()),
2857                                  CfaArg);
2858     SDValue FA = DAG.getNode(
2859         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2860         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2861     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2862                                   FA, Offset));
2863     break;
2864   }
2865   case ISD::FLT_ROUNDS_:
2866     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2867     Results.push_back(Node->getOperand(0));
2868     break;
2869   case ISD::EH_RETURN:
2870   case ISD::EH_LABEL:
2871   case ISD::PREFETCH:
2872   case ISD::VAEND:
2873   case ISD::EH_SJLJ_LONGJMP:
2874     // If the target didn't expand these, there's nothing to do, so just
2875     // preserve the chain and be done.
2876     Results.push_back(Node->getOperand(0));
2877     break;
2878   case ISD::READCYCLECOUNTER:
2879     // If the target didn't expand this, just return 'zero' and preserve the
2880     // chain.
2881     Results.append(Node->getNumValues() - 1,
2882                    DAG.getConstant(0, dl, Node->getValueType(0)));
2883     Results.push_back(Node->getOperand(0));
2884     break;
2885   case ISD::EH_SJLJ_SETJMP:
2886     // If the target didn't expand this, just return 'zero' and preserve the
2887     // chain.
2888     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2889     Results.push_back(Node->getOperand(0));
2890     break;
2891   case ISD::ATOMIC_LOAD: {
2892     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2893     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2894     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2895     SDValue Swap = DAG.getAtomicCmpSwap(
2896         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2897         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2898         cast<AtomicSDNode>(Node)->getMemOperand());
2899     Results.push_back(Swap.getValue(0));
2900     Results.push_back(Swap.getValue(1));
2901     break;
2902   }
2903   case ISD::ATOMIC_STORE: {
2904     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2905     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2906                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2907                                  Node->getOperand(0),
2908                                  Node->getOperand(1), Node->getOperand(2),
2909                                  cast<AtomicSDNode>(Node)->getMemOperand());
2910     Results.push_back(Swap.getValue(1));
2911     break;
2912   }
2913   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2914     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2915     // splits out the success value as a comparison. Expanding the resulting
2916     // ATOMIC_CMP_SWAP will produce a libcall.
2917     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2918     SDValue Res = DAG.getAtomicCmpSwap(
2919         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2920         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2921         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2922 
2923     SDValue ExtRes = Res;
2924     SDValue LHS = Res;
2925     SDValue RHS = Node->getOperand(1);
2926 
2927     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2928     EVT OuterType = Node->getValueType(0);
2929     switch (TLI.getExtendForAtomicOps()) {
2930     case ISD::SIGN_EXTEND:
2931       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2932                         DAG.getValueType(AtomicType));
2933       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2934                         Node->getOperand(2), DAG.getValueType(AtomicType));
2935       ExtRes = LHS;
2936       break;
2937     case ISD::ZERO_EXTEND:
2938       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2939                         DAG.getValueType(AtomicType));
2940       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2941       ExtRes = LHS;
2942       break;
2943     case ISD::ANY_EXTEND:
2944       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2945       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2946       break;
2947     default:
2948       llvm_unreachable("Invalid atomic op extension");
2949     }
2950 
2951     SDValue Success =
2952         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2953 
2954     Results.push_back(ExtRes.getValue(0));
2955     Results.push_back(Success);
2956     Results.push_back(Res.getValue(1));
2957     break;
2958   }
2959   case ISD::DYNAMIC_STACKALLOC:
2960     ExpandDYNAMIC_STACKALLOC(Node, Results);
2961     break;
2962   case ISD::MERGE_VALUES:
2963     for (unsigned i = 0; i < Node->getNumValues(); i++)
2964       Results.push_back(Node->getOperand(i));
2965     break;
2966   case ISD::UNDEF: {
2967     EVT VT = Node->getValueType(0);
2968     if (VT.isInteger())
2969       Results.push_back(DAG.getConstant(0, dl, VT));
2970     else {
2971       assert(VT.isFloatingPoint() && "Unknown value type!");
2972       Results.push_back(DAG.getConstantFP(0, dl, VT));
2973     }
2974     break;
2975   }
2976   case ISD::STRICT_FP_ROUND:
2977     // When strict mode is enforced we can't do expansion because it
2978     // does not honor the "strict" properties. Only libcall is allowed.
2979     if (TLI.isStrictFPEnabled())
2980       break;
2981     // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
2982     // since this operation is more efficient than stack operation.
2983     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2984                                        Node->getValueType(0))
2985         == TargetLowering::Legal)
2986       break;
2987     // We fall back to use stack operation when the FP_ROUND operation
2988     // isn't available.
2989     Tmp1 = EmitStackConvert(Node->getOperand(1),
2990                             Node->getValueType(0),
2991                             Node->getValueType(0), dl, Node->getOperand(0));
2992     ReplaceNode(Node, Tmp1.getNode());
2993     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_ROUND node\n");
2994     return true;
2995   case ISD::FP_ROUND:
2996   case ISD::BITCAST:
2997     Tmp1 = EmitStackConvert(Node->getOperand(0),
2998                             Node->getValueType(0),
2999                             Node->getValueType(0), dl);
3000     Results.push_back(Tmp1);
3001     break;
3002   case ISD::STRICT_FP_EXTEND:
3003     // When strict mode is enforced we can't do expansion because it
3004     // does not honor the "strict" properties. Only libcall is allowed.
3005     if (TLI.isStrictFPEnabled())
3006       break;
3007     // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
3008     // since this operation is more efficient than stack operation.
3009     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3010                                        Node->getValueType(0))
3011         == TargetLowering::Legal)
3012       break;
3013     // We fall back to use stack operation when the FP_EXTEND operation
3014     // isn't available.
3015     Tmp1 = EmitStackConvert(Node->getOperand(1),
3016                             Node->getOperand(1).getValueType(),
3017                             Node->getValueType(0), dl, Node->getOperand(0));
3018     ReplaceNode(Node, Tmp1.getNode());
3019     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_EXTEND node\n");
3020     return true;
3021   case ISD::FP_EXTEND:
3022     Tmp1 = EmitStackConvert(Node->getOperand(0),
3023                             Node->getOperand(0).getValueType(),
3024                             Node->getValueType(0), dl);
3025     Results.push_back(Tmp1);
3026     break;
3027   case ISD::SIGN_EXTEND_INREG: {
3028     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
3029     EVT VT = Node->getValueType(0);
3030 
3031     // An in-register sign-extend of a boolean is a negation:
3032     // 'true' (1) sign-extended is -1.
3033     // 'false' (0) sign-extended is 0.
3034     // However, we must mask the high bits of the source operand because the
3035     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
3036 
3037     // TODO: Do this for vectors too?
3038     if (ExtraVT.getSizeInBits() == 1) {
3039       SDValue One = DAG.getConstant(1, dl, VT);
3040       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
3041       SDValue Zero = DAG.getConstant(0, dl, VT);
3042       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
3043       Results.push_back(Neg);
3044       break;
3045     }
3046 
3047     // NOTE: we could fall back on load/store here too for targets without
3048     // SRA.  However, it is doubtful that any exist.
3049     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
3050     unsigned BitsDiff = VT.getScalarSizeInBits() -
3051                         ExtraVT.getScalarSizeInBits();
3052     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
3053     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
3054                        Node->getOperand(0), ShiftCst);
3055     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
3056     Results.push_back(Tmp1);
3057     break;
3058   }
3059   case ISD::UINT_TO_FP:
3060   case ISD::STRICT_UINT_TO_FP:
3061     if (TLI.expandUINT_TO_FP(Node, Tmp1, Tmp2, DAG)) {
3062       Results.push_back(Tmp1);
3063       if (Node->isStrictFPOpcode())
3064         Results.push_back(Tmp2);
3065       break;
3066     }
3067     LLVM_FALLTHROUGH;
3068   case ISD::SINT_TO_FP:
3069   case ISD::STRICT_SINT_TO_FP:
3070     Tmp1 = ExpandLegalINT_TO_FP(Node, Tmp2);
3071     Results.push_back(Tmp1);
3072     if (Node->isStrictFPOpcode())
3073       Results.push_back(Tmp2);
3074     break;
3075   case ISD::FP_TO_SINT:
3076     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
3077       Results.push_back(Tmp1);
3078     break;
3079   case ISD::STRICT_FP_TO_SINT:
3080     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG)) {
3081       ReplaceNode(Node, Tmp1.getNode());
3082       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_SINT node\n");
3083       return true;
3084     }
3085     break;
3086   case ISD::FP_TO_UINT:
3087     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG))
3088       Results.push_back(Tmp1);
3089     break;
3090   case ISD::STRICT_FP_TO_UINT:
3091     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG)) {
3092       // Relink the chain.
3093       DAG.ReplaceAllUsesOfValueWith(SDValue(Node,1), Tmp2);
3094       // Replace the new UINT result.
3095       ReplaceNodeWithValue(SDValue(Node, 0), Tmp1);
3096       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_UINT node\n");
3097       return true;
3098     }
3099     break;
3100   case ISD::VAARG:
3101     Results.push_back(DAG.expandVAArg(Node));
3102     Results.push_back(Results[0].getValue(1));
3103     break;
3104   case ISD::VACOPY:
3105     Results.push_back(DAG.expandVACopy(Node));
3106     break;
3107   case ISD::EXTRACT_VECTOR_ELT:
3108     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
3109       // This must be an access of the only element.  Return it.
3110       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
3111                          Node->getOperand(0));
3112     else
3113       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
3114     Results.push_back(Tmp1);
3115     break;
3116   case ISD::EXTRACT_SUBVECTOR:
3117     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
3118     break;
3119   case ISD::INSERT_SUBVECTOR:
3120     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3121     break;
3122   case ISD::CONCAT_VECTORS:
3123     Results.push_back(ExpandVectorBuildThroughStack(Node));
3124     break;
3125   case ISD::SCALAR_TO_VECTOR:
3126     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3127     break;
3128   case ISD::INSERT_VECTOR_ELT:
3129     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3130                                               Node->getOperand(1),
3131                                               Node->getOperand(2), dl));
3132     break;
3133   case ISD::VECTOR_SHUFFLE: {
3134     SmallVector<int, 32> NewMask;
3135     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3136 
3137     EVT VT = Node->getValueType(0);
3138     EVT EltVT = VT.getVectorElementType();
3139     SDValue Op0 = Node->getOperand(0);
3140     SDValue Op1 = Node->getOperand(1);
3141     if (!TLI.isTypeLegal(EltVT)) {
3142       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3143 
3144       // BUILD_VECTOR operands are allowed to be wider than the element type.
3145       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3146       // it.
3147       if (NewEltVT.bitsLT(EltVT)) {
3148         // Convert shuffle node.
3149         // If original node was v4i64 and the new EltVT is i32,
3150         // cast operands to v8i32 and re-build the mask.
3151 
3152         // Calculate new VT, the size of the new VT should be equal to original.
3153         EVT NewVT =
3154             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3155                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3156         assert(NewVT.bitsEq(VT));
3157 
3158         // cast operands to new VT
3159         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3160         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3161 
3162         // Convert the shuffle mask
3163         unsigned int factor =
3164                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3165 
3166         // EltVT gets smaller
3167         assert(factor > 0);
3168 
3169         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3170           if (Mask[i] < 0) {
3171             for (unsigned fi = 0; fi < factor; ++fi)
3172               NewMask.push_back(Mask[i]);
3173           }
3174           else {
3175             for (unsigned fi = 0; fi < factor; ++fi)
3176               NewMask.push_back(Mask[i]*factor+fi);
3177           }
3178         }
3179         Mask = NewMask;
3180         VT = NewVT;
3181       }
3182       EltVT = NewEltVT;
3183     }
3184     unsigned NumElems = VT.getVectorNumElements();
3185     SmallVector<SDValue, 16> Ops;
3186     for (unsigned i = 0; i != NumElems; ++i) {
3187       if (Mask[i] < 0) {
3188         Ops.push_back(DAG.getUNDEF(EltVT));
3189         continue;
3190       }
3191       unsigned Idx = Mask[i];
3192       if (Idx < NumElems)
3193         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3194                                   DAG.getVectorIdxConstant(Idx, dl)));
3195       else
3196         Ops.push_back(
3197             DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3198                         DAG.getVectorIdxConstant(Idx - NumElems, dl)));
3199     }
3200 
3201     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3202     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3203     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3204     Results.push_back(Tmp1);
3205     break;
3206   }
3207   case ISD::EXTRACT_ELEMENT: {
3208     EVT OpTy = Node->getOperand(0).getValueType();
3209     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3210       // 1 -> Hi
3211       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3212                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3213                                          TLI.getShiftAmountTy(
3214                                              Node->getOperand(0).getValueType(),
3215                                              DAG.getDataLayout())));
3216       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3217     } else {
3218       // 0 -> Lo
3219       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3220                          Node->getOperand(0));
3221     }
3222     Results.push_back(Tmp1);
3223     break;
3224   }
3225   case ISD::STACKSAVE:
3226     // Expand to CopyFromReg if the target set
3227     // StackPointerRegisterToSaveRestore.
3228     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3229       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3230                                            Node->getValueType(0)));
3231       Results.push_back(Results[0].getValue(1));
3232     } else {
3233       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3234       Results.push_back(Node->getOperand(0));
3235     }
3236     break;
3237   case ISD::STACKRESTORE:
3238     // Expand to CopyToReg if the target set
3239     // StackPointerRegisterToSaveRestore.
3240     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3241       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3242                                          Node->getOperand(1)));
3243     } else {
3244       Results.push_back(Node->getOperand(0));
3245     }
3246     break;
3247   case ISD::GET_DYNAMIC_AREA_OFFSET:
3248     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3249     Results.push_back(Results[0].getValue(0));
3250     break;
3251   case ISD::FCOPYSIGN:
3252     Results.push_back(ExpandFCOPYSIGN(Node));
3253     break;
3254   case ISD::FNEG:
3255     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3256     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3257     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3258     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3259                        Node->getOperand(0));
3260     Results.push_back(Tmp1);
3261     break;
3262   case ISD::FABS:
3263     Results.push_back(ExpandFABS(Node));
3264     break;
3265   case ISD::SMIN:
3266   case ISD::SMAX:
3267   case ISD::UMIN:
3268   case ISD::UMAX: {
3269     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3270     ISD::CondCode Pred;
3271     switch (Node->getOpcode()) {
3272     default: llvm_unreachable("How did we get here?");
3273     case ISD::SMAX: Pred = ISD::SETGT; break;
3274     case ISD::SMIN: Pred = ISD::SETLT; break;
3275     case ISD::UMAX: Pred = ISD::SETUGT; break;
3276     case ISD::UMIN: Pred = ISD::SETULT; break;
3277     }
3278     Tmp1 = Node->getOperand(0);
3279     Tmp2 = Node->getOperand(1);
3280     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3281     Results.push_back(Tmp1);
3282     break;
3283   }
3284   case ISD::FMINNUM:
3285   case ISD::FMAXNUM: {
3286     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3287       Results.push_back(Expanded);
3288     break;
3289   }
3290   case ISD::FSIN:
3291   case ISD::FCOS: {
3292     EVT VT = Node->getValueType(0);
3293     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3294     // fcos which share the same operand and both are used.
3295     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3296          isSinCosLibcallAvailable(Node, TLI))
3297         && useSinCos(Node)) {
3298       SDVTList VTs = DAG.getVTList(VT, VT);
3299       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3300       if (Node->getOpcode() == ISD::FCOS)
3301         Tmp1 = Tmp1.getValue(1);
3302       Results.push_back(Tmp1);
3303     }
3304     break;
3305   }
3306   case ISD::FMAD:
3307     llvm_unreachable("Illegal fmad should never be formed");
3308 
3309   case ISD::FP16_TO_FP:
3310     if (Node->getValueType(0) != MVT::f32) {
3311       // We can extend to types bigger than f32 in two steps without changing
3312       // the result. Since "f16 -> f32" is much more commonly available, give
3313       // CodeGen the option of emitting that before resorting to a libcall.
3314       SDValue Res =
3315           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3316       Results.push_back(
3317           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3318     }
3319     break;
3320   case ISD::STRICT_FP16_TO_FP:
3321     if (Node->getValueType(0) != MVT::f32) {
3322       // We can extend to types bigger than f32 in two steps without changing
3323       // the result. Since "f16 -> f32" is much more commonly available, give
3324       // CodeGen the option of emitting that before resorting to a libcall.
3325       SDValue Res =
3326           DAG.getNode(ISD::STRICT_FP16_TO_FP, dl, {MVT::f32, MVT::Other},
3327                       {Node->getOperand(0), Node->getOperand(1)});
3328       Res = DAG.getNode(ISD::STRICT_FP_EXTEND, dl,
3329                         {Node->getValueType(0), MVT::Other},
3330                         {Res.getValue(1), Res});
3331       Results.push_back(Res);
3332       Results.push_back(Res.getValue(1));
3333     }
3334     break;
3335   case ISD::FP_TO_FP16:
3336     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3337     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3338       SDValue Op = Node->getOperand(0);
3339       MVT SVT = Op.getSimpleValueType();
3340       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3341           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3342         // Under fastmath, we can expand this node into a fround followed by
3343         // a float-half conversion.
3344         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3345                                        DAG.getIntPtrConstant(0, dl));
3346         Results.push_back(
3347             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3348       }
3349     }
3350     break;
3351   case ISD::ConstantFP: {
3352     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3353     // Check to see if this FP immediate is already legal.
3354     // If this is a legal constant, turn it into a TargetConstantFP node.
3355     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0),
3356                           DAG.shouldOptForSize()))
3357       Results.push_back(ExpandConstantFP(CFP, true));
3358     break;
3359   }
3360   case ISD::Constant: {
3361     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3362     Results.push_back(ExpandConstant(CP));
3363     break;
3364   }
3365   case ISD::FSUB: {
3366     EVT VT = Node->getValueType(0);
3367     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3368         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3369       const SDNodeFlags Flags = Node->getFlags();
3370       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3371       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3372       Results.push_back(Tmp1);
3373     }
3374     break;
3375   }
3376   case ISD::SUB: {
3377     EVT VT = Node->getValueType(0);
3378     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3379            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3380            "Don't know how to expand this subtraction!");
3381     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3382                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3383                                VT));
3384     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3385     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3386     break;
3387   }
3388   case ISD::UREM:
3389   case ISD::SREM:
3390     if (TLI.expandREM(Node, Tmp1, DAG))
3391       Results.push_back(Tmp1);
3392     break;
3393   case ISD::UDIV:
3394   case ISD::SDIV: {
3395     bool isSigned = Node->getOpcode() == ISD::SDIV;
3396     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3397     EVT VT = Node->getValueType(0);
3398     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3399       SDVTList VTs = DAG.getVTList(VT, VT);
3400       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3401                          Node->getOperand(1));
3402       Results.push_back(Tmp1);
3403     }
3404     break;
3405   }
3406   case ISD::MULHU:
3407   case ISD::MULHS: {
3408     unsigned ExpandOpcode =
3409         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3410     EVT VT = Node->getValueType(0);
3411     SDVTList VTs = DAG.getVTList(VT, VT);
3412 
3413     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3414                        Node->getOperand(1));
3415     Results.push_back(Tmp1.getValue(1));
3416     break;
3417   }
3418   case ISD::UMUL_LOHI:
3419   case ISD::SMUL_LOHI: {
3420     SDValue LHS = Node->getOperand(0);
3421     SDValue RHS = Node->getOperand(1);
3422     MVT VT = LHS.getSimpleValueType();
3423     unsigned MULHOpcode =
3424         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3425 
3426     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3427       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3428       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3429       break;
3430     }
3431 
3432     SmallVector<SDValue, 4> Halves;
3433     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3434     assert(TLI.isTypeLegal(HalfType));
3435     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, dl, LHS, RHS, Halves,
3436                            HalfType, DAG,
3437                            TargetLowering::MulExpansionKind::Always)) {
3438       for (unsigned i = 0; i < 2; ++i) {
3439         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3440         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3441         SDValue Shift = DAG.getConstant(
3442             HalfType.getScalarSizeInBits(), dl,
3443             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3444         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3445         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3446       }
3447       break;
3448     }
3449     break;
3450   }
3451   case ISD::MUL: {
3452     EVT VT = Node->getValueType(0);
3453     SDVTList VTs = DAG.getVTList(VT, VT);
3454     // See if multiply or divide can be lowered using two-result operations.
3455     // We just need the low half of the multiply; try both the signed
3456     // and unsigned forms. If the target supports both SMUL_LOHI and
3457     // UMUL_LOHI, form a preference by checking which forms of plain
3458     // MULH it supports.
3459     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3460     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3461     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3462     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3463     unsigned OpToUse = 0;
3464     if (HasSMUL_LOHI && !HasMULHS) {
3465       OpToUse = ISD::SMUL_LOHI;
3466     } else if (HasUMUL_LOHI && !HasMULHU) {
3467       OpToUse = ISD::UMUL_LOHI;
3468     } else if (HasSMUL_LOHI) {
3469       OpToUse = ISD::SMUL_LOHI;
3470     } else if (HasUMUL_LOHI) {
3471       OpToUse = ISD::UMUL_LOHI;
3472     }
3473     if (OpToUse) {
3474       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3475                                     Node->getOperand(1)));
3476       break;
3477     }
3478 
3479     SDValue Lo, Hi;
3480     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3481     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3482         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3483         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3484         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3485         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3486                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3487       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3488       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3489       SDValue Shift =
3490           DAG.getConstant(HalfType.getSizeInBits(), dl,
3491                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3492       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3493       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3494     }
3495     break;
3496   }
3497   case ISD::FSHL:
3498   case ISD::FSHR:
3499     if (TLI.expandFunnelShift(Node, Tmp1, DAG))
3500       Results.push_back(Tmp1);
3501     break;
3502   case ISD::ROTL:
3503   case ISD::ROTR:
3504     if (TLI.expandROT(Node, Tmp1, DAG))
3505       Results.push_back(Tmp1);
3506     break;
3507   case ISD::SADDSAT:
3508   case ISD::UADDSAT:
3509   case ISD::SSUBSAT:
3510   case ISD::USUBSAT:
3511     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3512     break;
3513   case ISD::SSHLSAT:
3514   case ISD::USHLSAT:
3515     Results.push_back(TLI.expandShlSat(Node, DAG));
3516     break;
3517   case ISD::SMULFIX:
3518   case ISD::SMULFIXSAT:
3519   case ISD::UMULFIX:
3520   case ISD::UMULFIXSAT:
3521     Results.push_back(TLI.expandFixedPointMul(Node, DAG));
3522     break;
3523   case ISD::SDIVFIX:
3524   case ISD::SDIVFIXSAT:
3525   case ISD::UDIVFIX:
3526   case ISD::UDIVFIXSAT:
3527     if (SDValue V = TLI.expandFixedPointDiv(Node->getOpcode(), SDLoc(Node),
3528                                             Node->getOperand(0),
3529                                             Node->getOperand(1),
3530                                             Node->getConstantOperandVal(2),
3531                                             DAG)) {
3532       Results.push_back(V);
3533       break;
3534     }
3535     // FIXME: We might want to retry here with a wider type if we fail, if that
3536     // type is legal.
3537     // FIXME: Technically, so long as we only have sdivfixes where BW+Scale is
3538     // <= 128 (which is the case for all of the default Embedded-C types),
3539     // we will only get here with types and scales that we could always expand
3540     // if we were allowed to generate libcalls to division functions of illegal
3541     // type. But we cannot do that.
3542     llvm_unreachable("Cannot expand DIVFIX!");
3543   case ISD::ADDCARRY:
3544   case ISD::SUBCARRY: {
3545     SDValue LHS = Node->getOperand(0);
3546     SDValue RHS = Node->getOperand(1);
3547     SDValue Carry = Node->getOperand(2);
3548 
3549     bool IsAdd = Node->getOpcode() == ISD::ADDCARRY;
3550 
3551     // Initial add of the 2 operands.
3552     unsigned Op = IsAdd ? ISD::ADD : ISD::SUB;
3553     EVT VT = LHS.getValueType();
3554     SDValue Sum = DAG.getNode(Op, dl, VT, LHS, RHS);
3555 
3556     // Initial check for overflow.
3557     EVT CarryType = Node->getValueType(1);
3558     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3559     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3560     SDValue Overflow = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3561 
3562     // Add of the sum and the carry.
3563     SDValue One = DAG.getConstant(1, dl, VT);
3564     SDValue CarryExt =
3565         DAG.getNode(ISD::AND, dl, VT, DAG.getZExtOrTrunc(Carry, dl, VT), One);
3566     SDValue Sum2 = DAG.getNode(Op, dl, VT, Sum, CarryExt);
3567 
3568     // Second check for overflow. If we are adding, we can only overflow if the
3569     // initial sum is all 1s ang the carry is set, resulting in a new sum of 0.
3570     // If we are subtracting, we can only overflow if the initial sum is 0 and
3571     // the carry is set, resulting in a new sum of all 1s.
3572     SDValue Zero = DAG.getConstant(0, dl, VT);
3573     SDValue Overflow2 =
3574         IsAdd ? DAG.getSetCC(dl, SetCCType, Sum2, Zero, ISD::SETEQ)
3575               : DAG.getSetCC(dl, SetCCType, Sum, Zero, ISD::SETEQ);
3576     Overflow2 = DAG.getNode(ISD::AND, dl, SetCCType, Overflow2,
3577                             DAG.getZExtOrTrunc(Carry, dl, SetCCType));
3578 
3579     SDValue ResultCarry =
3580         DAG.getNode(ISD::OR, dl, SetCCType, Overflow, Overflow2);
3581 
3582     Results.push_back(Sum2);
3583     Results.push_back(DAG.getBoolExtOrTrunc(ResultCarry, dl, CarryType, VT));
3584     break;
3585   }
3586   case ISD::SADDO:
3587   case ISD::SSUBO: {
3588     SDValue Result, Overflow;
3589     TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
3590     Results.push_back(Result);
3591     Results.push_back(Overflow);
3592     break;
3593   }
3594   case ISD::UADDO:
3595   case ISD::USUBO: {
3596     SDValue Result, Overflow;
3597     TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
3598     Results.push_back(Result);
3599     Results.push_back(Overflow);
3600     break;
3601   }
3602   case ISD::UMULO:
3603   case ISD::SMULO: {
3604     SDValue Result, Overflow;
3605     if (TLI.expandMULO(Node, Result, Overflow, DAG)) {
3606       Results.push_back(Result);
3607       Results.push_back(Overflow);
3608     }
3609     break;
3610   }
3611   case ISD::BUILD_PAIR: {
3612     EVT PairTy = Node->getValueType(0);
3613     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3614     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3615     Tmp2 = DAG.getNode(
3616         ISD::SHL, dl, PairTy, Tmp2,
3617         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3618                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3619     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3620     break;
3621   }
3622   case ISD::SELECT:
3623     Tmp1 = Node->getOperand(0);
3624     Tmp2 = Node->getOperand(1);
3625     Tmp3 = Node->getOperand(2);
3626     if (Tmp1.getOpcode() == ISD::SETCC) {
3627       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3628                              Tmp2, Tmp3,
3629                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3630     } else {
3631       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3632                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3633                              Tmp2, Tmp3, ISD::SETNE);
3634     }
3635     Tmp1->setFlags(Node->getFlags());
3636     Results.push_back(Tmp1);
3637     break;
3638   case ISD::BR_JT: {
3639     SDValue Chain = Node->getOperand(0);
3640     SDValue Table = Node->getOperand(1);
3641     SDValue Index = Node->getOperand(2);
3642 
3643     const DataLayout &TD = DAG.getDataLayout();
3644     EVT PTy = TLI.getPointerTy(TD);
3645 
3646     unsigned EntrySize =
3647       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3648 
3649     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3650     // This transformation needs to be done here since otherwise the MIPS
3651     // backend will end up emitting a three instruction multiply sequence
3652     // instead of a single shift and MSP430 will call a runtime function.
3653     if (llvm::isPowerOf2_32(EntrySize))
3654       Index = DAG.getNode(
3655           ISD::SHL, dl, Index.getValueType(), Index,
3656           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3657     else
3658       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3659                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3660     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3661                                Index, Table);
3662 
3663     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3664     SDValue LD = DAG.getExtLoad(
3665         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3666         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3667     Addr = LD;
3668     if (TLI.isJumpTableRelative()) {
3669       // For PIC, the sequence is:
3670       // BRIND(load(Jumptable + index) + RelocBase)
3671       // RelocBase can be JumpTable, GOT or some sort of global base.
3672       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3673                           TLI.getPICJumpTableRelocBase(Table, DAG));
3674     }
3675 
3676     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3677     Results.push_back(Tmp1);
3678     break;
3679   }
3680   case ISD::BRCOND:
3681     // Expand brcond's setcc into its constituent parts and create a BR_CC
3682     // Node.
3683     Tmp1 = Node->getOperand(0);
3684     Tmp2 = Node->getOperand(1);
3685     if (Tmp2.getOpcode() == ISD::SETCC) {
3686       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3687                          Tmp1, Tmp2.getOperand(2),
3688                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3689                          Node->getOperand(2));
3690     } else {
3691       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3692       if (Tmp2.isUndef() ||
3693           (Tmp2.getOpcode() == ISD::AND &&
3694            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3695            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3696         Tmp3 = Tmp2;
3697       else
3698         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3699                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3700       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3701                          DAG.getCondCode(ISD::SETNE), Tmp3,
3702                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3703                          Node->getOperand(2));
3704     }
3705     Results.push_back(Tmp1);
3706     break;
3707   case ISD::SETCC:
3708   case ISD::STRICT_FSETCC:
3709   case ISD::STRICT_FSETCCS: {
3710     bool IsStrict = Node->getOpcode() != ISD::SETCC;
3711     bool IsSignaling = Node->getOpcode() == ISD::STRICT_FSETCCS;
3712     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
3713     unsigned Offset = IsStrict ? 1 : 0;
3714     Tmp1 = Node->getOperand(0 + Offset);
3715     Tmp2 = Node->getOperand(1 + Offset);
3716     Tmp3 = Node->getOperand(2 + Offset);
3717     bool Legalized =
3718         LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2, Tmp3,
3719                               NeedInvert, dl, Chain, IsSignaling);
3720 
3721     if (Legalized) {
3722       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3723       // condition code, create a new SETCC node.
3724       if (Tmp3.getNode())
3725         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3726                            Tmp1, Tmp2, Tmp3, Node->getFlags());
3727 
3728       // If we expanded the SETCC by inverting the condition code, then wrap
3729       // the existing SETCC in a NOT to restore the intended condition.
3730       if (NeedInvert)
3731         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3732 
3733       Results.push_back(Tmp1);
3734       if (IsStrict)
3735         Results.push_back(Chain);
3736 
3737       break;
3738     }
3739 
3740     // FIXME: It seems Legalized is false iff CCCode is Legal. I don't
3741     // understand if this code is useful for strict nodes.
3742     assert(!IsStrict && "Don't know how to expand for strict nodes.");
3743 
3744     // Otherwise, SETCC for the given comparison type must be completely
3745     // illegal; expand it into a SELECT_CC.
3746     EVT VT = Node->getValueType(0);
3747     int TrueValue;
3748     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3749     case TargetLowering::ZeroOrOneBooleanContent:
3750     case TargetLowering::UndefinedBooleanContent:
3751       TrueValue = 1;
3752       break;
3753     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3754       TrueValue = -1;
3755       break;
3756     }
3757     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3758                        DAG.getConstant(TrueValue, dl, VT),
3759                        DAG.getConstant(0, dl, VT),
3760                        Tmp3);
3761     Tmp1->setFlags(Node->getFlags());
3762     Results.push_back(Tmp1);
3763     break;
3764   }
3765   case ISD::SELECT_CC: {
3766     // TODO: need to add STRICT_SELECT_CC and STRICT_SELECT_CCS
3767     Tmp1 = Node->getOperand(0);   // LHS
3768     Tmp2 = Node->getOperand(1);   // RHS
3769     Tmp3 = Node->getOperand(2);   // True
3770     Tmp4 = Node->getOperand(3);   // False
3771     EVT VT = Node->getValueType(0);
3772     SDValue Chain;
3773     SDValue CC = Node->getOperand(4);
3774     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3775 
3776     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3777       // If the condition code is legal, then we need to expand this
3778       // node using SETCC and SELECT.
3779       EVT CmpVT = Tmp1.getValueType();
3780       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3781              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3782              "expanded.");
3783       EVT CCVT = getSetCCResultType(CmpVT);
3784       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC, Node->getFlags());
3785       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3786       break;
3787     }
3788 
3789     // SELECT_CC is legal, so the condition code must not be.
3790     bool Legalized = false;
3791     // Try to legalize by inverting the condition.  This is for targets that
3792     // might support an ordered version of a condition, but not the unordered
3793     // version (or vice versa).
3794     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp, Tmp1.getValueType());
3795     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3796       // Use the new condition code and swap true and false
3797       Legalized = true;
3798       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3799       Tmp1->setFlags(Node->getFlags());
3800     } else {
3801       // If The inverse is not legal, then try to swap the arguments using
3802       // the inverse condition code.
3803       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3804       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3805         // The swapped inverse condition is legal, so swap true and false,
3806         // lhs and rhs.
3807         Legalized = true;
3808         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3809         Tmp1->setFlags(Node->getFlags());
3810       }
3811     }
3812 
3813     if (!Legalized) {
3814       Legalized = LegalizeSetCCCondCode(getSetCCResultType(Tmp1.getValueType()),
3815                                         Tmp1, Tmp2, CC, NeedInvert, dl, Chain);
3816 
3817       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3818 
3819       // If we expanded the SETCC by inverting the condition code, then swap
3820       // the True/False operands to match.
3821       if (NeedInvert)
3822         std::swap(Tmp3, Tmp4);
3823 
3824       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3825       // condition code, create a new SELECT_CC node.
3826       if (CC.getNode()) {
3827         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3828                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3829       } else {
3830         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3831         CC = DAG.getCondCode(ISD::SETNE);
3832         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3833                            Tmp2, Tmp3, Tmp4, CC);
3834       }
3835       Tmp1->setFlags(Node->getFlags());
3836     }
3837     Results.push_back(Tmp1);
3838     break;
3839   }
3840   case ISD::BR_CC: {
3841     // TODO: need to add STRICT_BR_CC and STRICT_BR_CCS
3842     SDValue Chain;
3843     Tmp1 = Node->getOperand(0);              // Chain
3844     Tmp2 = Node->getOperand(2);              // LHS
3845     Tmp3 = Node->getOperand(3);              // RHS
3846     Tmp4 = Node->getOperand(1);              // CC
3847 
3848     bool Legalized =
3849         LegalizeSetCCCondCode(getSetCCResultType(Tmp2.getValueType()), Tmp2,
3850                               Tmp3, Tmp4, NeedInvert, dl, Chain);
3851     (void)Legalized;
3852     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3853 
3854     assert(!NeedInvert && "Don't know how to invert BR_CC!");
3855 
3856     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3857     // node.
3858     if (Tmp4.getNode()) {
3859       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3860                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3861     } else {
3862       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3863       Tmp4 = DAG.getCondCode(ISD::SETNE);
3864       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3865                          Tmp2, Tmp3, Node->getOperand(4));
3866     }
3867     Results.push_back(Tmp1);
3868     break;
3869   }
3870   case ISD::BUILD_VECTOR:
3871     Results.push_back(ExpandBUILD_VECTOR(Node));
3872     break;
3873   case ISD::SPLAT_VECTOR:
3874     Results.push_back(ExpandSPLAT_VECTOR(Node));
3875     break;
3876   case ISD::SRA:
3877   case ISD::SRL:
3878   case ISD::SHL: {
3879     // Scalarize vector SRA/SRL/SHL.
3880     EVT VT = Node->getValueType(0);
3881     assert(VT.isVector() && "Unable to legalize non-vector shift");
3882     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3883     unsigned NumElem = VT.getVectorNumElements();
3884 
3885     SmallVector<SDValue, 8> Scalars;
3886     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3887       SDValue Ex =
3888           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3889                       Node->getOperand(0), DAG.getVectorIdxConstant(Idx, dl));
3890       SDValue Sh =
3891           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3892                       Node->getOperand(1), DAG.getVectorIdxConstant(Idx, dl));
3893       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3894                                     VT.getScalarType(), Ex, Sh));
3895     }
3896 
3897     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3898     Results.push_back(Result);
3899     break;
3900   }
3901   case ISD::VECREDUCE_FADD:
3902   case ISD::VECREDUCE_FMUL:
3903   case ISD::VECREDUCE_ADD:
3904   case ISD::VECREDUCE_MUL:
3905   case ISD::VECREDUCE_AND:
3906   case ISD::VECREDUCE_OR:
3907   case ISD::VECREDUCE_XOR:
3908   case ISD::VECREDUCE_SMAX:
3909   case ISD::VECREDUCE_SMIN:
3910   case ISD::VECREDUCE_UMAX:
3911   case ISD::VECREDUCE_UMIN:
3912   case ISD::VECREDUCE_FMAX:
3913   case ISD::VECREDUCE_FMIN:
3914     Results.push_back(TLI.expandVecReduce(Node, DAG));
3915     break;
3916   case ISD::GLOBAL_OFFSET_TABLE:
3917   case ISD::GlobalAddress:
3918   case ISD::GlobalTLSAddress:
3919   case ISD::ExternalSymbol:
3920   case ISD::ConstantPool:
3921   case ISD::JumpTable:
3922   case ISD::INTRINSIC_W_CHAIN:
3923   case ISD::INTRINSIC_WO_CHAIN:
3924   case ISD::INTRINSIC_VOID:
3925     // FIXME: Custom lowering for these operations shouldn't return null!
3926     // Return true so that we don't call ConvertNodeToLibcall which also won't
3927     // do anything.
3928     return true;
3929   }
3930 
3931   if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
3932     // FIXME: We were asked to expand a strict floating-point operation,
3933     // but there is currently no expansion implemented that would preserve
3934     // the "strict" properties.  For now, we just fall back to the non-strict
3935     // version if that is legal on the target.  The actual mutation of the
3936     // operation will happen in SelectionDAGISel::DoInstructionSelection.
3937     switch (Node->getOpcode()) {
3938     default:
3939       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3940                                          Node->getValueType(0))
3941           == TargetLowering::Legal)
3942         return true;
3943       break;
3944     case ISD::STRICT_FSUB: {
3945       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3946                                          Node->getValueType(0))
3947           == TargetLowering::Legal)
3948         return true;
3949 
3950       EVT VT = Node->getValueType(0);
3951       const SDNodeFlags Flags = Node->getFlags();
3952       SDValue Neg = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(2), Flags);
3953       SDValue Fadd = DAG.getNode(ISD::STRICT_FADD, dl, Node->getVTList(),
3954                                  {Node->getOperand(0), Node->getOperand(1), Neg},
3955                          Flags);
3956 
3957       Results.push_back(Fadd);
3958       Results.push_back(Fadd.getValue(1));
3959       break;
3960     }
3961     case ISD::STRICT_LRINT:
3962     case ISD::STRICT_LLRINT:
3963     case ISD::STRICT_LROUND:
3964     case ISD::STRICT_LLROUND:
3965       // These are registered by the operand type instead of the value
3966       // type. Reflect that here.
3967       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3968                                          Node->getOperand(1).getValueType())
3969           == TargetLowering::Legal)
3970         return true;
3971       break;
3972     }
3973   }
3974 
3975   // Replace the original node with the legalized result.
3976   if (Results.empty()) {
3977     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3978     return false;
3979   }
3980 
3981   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3982   ReplaceNode(Node, Results.data());
3983   return true;
3984 }
3985 
3986 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3987   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3988   SmallVector<SDValue, 8> Results;
3989   SDLoc dl(Node);
3990   // FIXME: Check flags on the node to see if we can use a finite call.
3991   unsigned Opc = Node->getOpcode();
3992   switch (Opc) {
3993   case ISD::ATOMIC_FENCE: {
3994     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3995     // FIXME: handle "fence singlethread" more efficiently.
3996     TargetLowering::ArgListTy Args;
3997 
3998     TargetLowering::CallLoweringInfo CLI(DAG);
3999     CLI.setDebugLoc(dl)
4000         .setChain(Node->getOperand(0))
4001         .setLibCallee(
4002             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
4003             DAG.getExternalSymbol("__sync_synchronize",
4004                                   TLI.getPointerTy(DAG.getDataLayout())),
4005             std::move(Args));
4006 
4007     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
4008 
4009     Results.push_back(CallResult.second);
4010     break;
4011   }
4012   // By default, atomic intrinsics are marked Legal and lowered. Targets
4013   // which don't support them directly, however, may want libcalls, in which
4014   // case they mark them Expand, and we get here.
4015   case ISD::ATOMIC_SWAP:
4016   case ISD::ATOMIC_LOAD_ADD:
4017   case ISD::ATOMIC_LOAD_SUB:
4018   case ISD::ATOMIC_LOAD_AND:
4019   case ISD::ATOMIC_LOAD_CLR:
4020   case ISD::ATOMIC_LOAD_OR:
4021   case ISD::ATOMIC_LOAD_XOR:
4022   case ISD::ATOMIC_LOAD_NAND:
4023   case ISD::ATOMIC_LOAD_MIN:
4024   case ISD::ATOMIC_LOAD_MAX:
4025   case ISD::ATOMIC_LOAD_UMIN:
4026   case ISD::ATOMIC_LOAD_UMAX:
4027   case ISD::ATOMIC_CMP_SWAP: {
4028     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
4029     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
4030     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
4031 
4032     EVT RetVT = Node->getValueType(0);
4033     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
4034     TargetLowering::MakeLibCallOptions CallOptions;
4035     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
4036                                                       Ops, CallOptions,
4037                                                       SDLoc(Node),
4038                                                       Node->getOperand(0));
4039     Results.push_back(Tmp.first);
4040     Results.push_back(Tmp.second);
4041     break;
4042   }
4043   case ISD::TRAP: {
4044     // If this operation is not supported, lower it to 'abort()' call
4045     TargetLowering::ArgListTy Args;
4046     TargetLowering::CallLoweringInfo CLI(DAG);
4047     CLI.setDebugLoc(dl)
4048         .setChain(Node->getOperand(0))
4049         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
4050                       DAG.getExternalSymbol(
4051                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
4052                       std::move(Args));
4053     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
4054 
4055     Results.push_back(CallResult.second);
4056     break;
4057   }
4058   case ISD::FMINNUM:
4059   case ISD::STRICT_FMINNUM:
4060     ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
4061                     RTLIB::FMIN_F80, RTLIB::FMIN_F128,
4062                     RTLIB::FMIN_PPCF128, Results);
4063     break;
4064   case ISD::FMAXNUM:
4065   case ISD::STRICT_FMAXNUM:
4066     ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
4067                     RTLIB::FMAX_F80, RTLIB::FMAX_F128,
4068                     RTLIB::FMAX_PPCF128, Results);
4069     break;
4070   case ISD::FSQRT:
4071   case ISD::STRICT_FSQRT:
4072     ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
4073                     RTLIB::SQRT_F80, RTLIB::SQRT_F128,
4074                     RTLIB::SQRT_PPCF128, Results);
4075     break;
4076   case ISD::FCBRT:
4077     ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
4078                     RTLIB::CBRT_F80, RTLIB::CBRT_F128,
4079                     RTLIB::CBRT_PPCF128, Results);
4080     break;
4081   case ISD::FSIN:
4082   case ISD::STRICT_FSIN:
4083     ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
4084                     RTLIB::SIN_F80, RTLIB::SIN_F128,
4085                     RTLIB::SIN_PPCF128, Results);
4086     break;
4087   case ISD::FCOS:
4088   case ISD::STRICT_FCOS:
4089     ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
4090                     RTLIB::COS_F80, RTLIB::COS_F128,
4091                     RTLIB::COS_PPCF128, Results);
4092     break;
4093   case ISD::FSINCOS:
4094     // Expand into sincos libcall.
4095     ExpandSinCosLibCall(Node, Results);
4096     break;
4097   case ISD::FLOG:
4098   case ISD::STRICT_FLOG:
4099     ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64, RTLIB::LOG_F80,
4100                     RTLIB::LOG_F128, RTLIB::LOG_PPCF128, Results);
4101     break;
4102   case ISD::FLOG2:
4103   case ISD::STRICT_FLOG2:
4104     ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64, RTLIB::LOG2_F80,
4105                     RTLIB::LOG2_F128, RTLIB::LOG2_PPCF128, Results);
4106     break;
4107   case ISD::FLOG10:
4108   case ISD::STRICT_FLOG10:
4109     ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64, RTLIB::LOG10_F80,
4110                     RTLIB::LOG10_F128, RTLIB::LOG10_PPCF128, Results);
4111     break;
4112   case ISD::FEXP:
4113   case ISD::STRICT_FEXP:
4114     ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64, RTLIB::EXP_F80,
4115                     RTLIB::EXP_F128, RTLIB::EXP_PPCF128, Results);
4116     break;
4117   case ISD::FEXP2:
4118   case ISD::STRICT_FEXP2:
4119     ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64, RTLIB::EXP2_F80,
4120                     RTLIB::EXP2_F128, RTLIB::EXP2_PPCF128, Results);
4121     break;
4122   case ISD::FTRUNC:
4123   case ISD::STRICT_FTRUNC:
4124     ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4125                     RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4126                     RTLIB::TRUNC_PPCF128, Results);
4127     break;
4128   case ISD::FFLOOR:
4129   case ISD::STRICT_FFLOOR:
4130     ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4131                     RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4132                     RTLIB::FLOOR_PPCF128, Results);
4133     break;
4134   case ISD::FCEIL:
4135   case ISD::STRICT_FCEIL:
4136     ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4137                     RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4138                     RTLIB::CEIL_PPCF128, Results);
4139     break;
4140   case ISD::FRINT:
4141   case ISD::STRICT_FRINT:
4142     ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4143                     RTLIB::RINT_F80, RTLIB::RINT_F128,
4144                     RTLIB::RINT_PPCF128, Results);
4145     break;
4146   case ISD::FNEARBYINT:
4147   case ISD::STRICT_FNEARBYINT:
4148     ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4149                     RTLIB::NEARBYINT_F64,
4150                     RTLIB::NEARBYINT_F80,
4151                     RTLIB::NEARBYINT_F128,
4152                     RTLIB::NEARBYINT_PPCF128, Results);
4153     break;
4154   case ISD::FROUND:
4155   case ISD::STRICT_FROUND:
4156     ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4157                     RTLIB::ROUND_F64,
4158                     RTLIB::ROUND_F80,
4159                     RTLIB::ROUND_F128,
4160                     RTLIB::ROUND_PPCF128, Results);
4161     break;
4162   case ISD::FROUNDEVEN:
4163   case ISD::STRICT_FROUNDEVEN:
4164     ExpandFPLibCall(Node, RTLIB::ROUNDEVEN_F32,
4165                     RTLIB::ROUNDEVEN_F64,
4166                     RTLIB::ROUNDEVEN_F80,
4167                     RTLIB::ROUNDEVEN_F128,
4168                     RTLIB::ROUNDEVEN_PPCF128, Results);
4169     break;
4170   case ISD::FPOWI:
4171   case ISD::STRICT_FPOWI: {
4172     RTLIB::Libcall LC;
4173     switch (Node->getSimpleValueType(0).SimpleTy) {
4174     default: llvm_unreachable("Unexpected request for libcall!");
4175     case MVT::f32: LC = RTLIB::POWI_F32; break;
4176     case MVT::f64: LC = RTLIB::POWI_F64; break;
4177     case MVT::f80: LC = RTLIB::POWI_F80; break;
4178     case MVT::f128: LC = RTLIB::POWI_F128; break;
4179     case MVT::ppcf128: LC = RTLIB::POWI_PPCF128; break;
4180     }
4181     if (!TLI.getLibcallName(LC)) {
4182       // Some targets don't have a powi libcall; use pow instead.
4183       SDValue Exponent = DAG.getNode(ISD::SINT_TO_FP, SDLoc(Node),
4184                                      Node->getValueType(0),
4185                                      Node->getOperand(1));
4186       Results.push_back(DAG.getNode(ISD::FPOW, SDLoc(Node),
4187                                     Node->getValueType(0), Node->getOperand(0),
4188                                     Exponent));
4189       break;
4190     }
4191     ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
4192                     RTLIB::POWI_F80, RTLIB::POWI_F128,
4193                     RTLIB::POWI_PPCF128, Results);
4194     break;
4195   }
4196   case ISD::FPOW:
4197   case ISD::STRICT_FPOW:
4198     ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64, RTLIB::POW_F80,
4199                     RTLIB::POW_F128, RTLIB::POW_PPCF128, Results);
4200     break;
4201   case ISD::LROUND:
4202   case ISD::STRICT_LROUND:
4203     ExpandArgFPLibCall(Node, RTLIB::LROUND_F32,
4204                        RTLIB::LROUND_F64, RTLIB::LROUND_F80,
4205                        RTLIB::LROUND_F128,
4206                        RTLIB::LROUND_PPCF128, Results);
4207     break;
4208   case ISD::LLROUND:
4209   case ISD::STRICT_LLROUND:
4210     ExpandArgFPLibCall(Node, RTLIB::LLROUND_F32,
4211                        RTLIB::LLROUND_F64, RTLIB::LLROUND_F80,
4212                        RTLIB::LLROUND_F128,
4213                        RTLIB::LLROUND_PPCF128, Results);
4214     break;
4215   case ISD::LRINT:
4216   case ISD::STRICT_LRINT:
4217     ExpandArgFPLibCall(Node, RTLIB::LRINT_F32,
4218                        RTLIB::LRINT_F64, RTLIB::LRINT_F80,
4219                        RTLIB::LRINT_F128,
4220                        RTLIB::LRINT_PPCF128, Results);
4221     break;
4222   case ISD::LLRINT:
4223   case ISD::STRICT_LLRINT:
4224     ExpandArgFPLibCall(Node, RTLIB::LLRINT_F32,
4225                        RTLIB::LLRINT_F64, RTLIB::LLRINT_F80,
4226                        RTLIB::LLRINT_F128,
4227                        RTLIB::LLRINT_PPCF128, Results);
4228     break;
4229   case ISD::FDIV:
4230   case ISD::STRICT_FDIV:
4231     ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4232                     RTLIB::DIV_F80, RTLIB::DIV_F128,
4233                     RTLIB::DIV_PPCF128, Results);
4234     break;
4235   case ISD::FREM:
4236   case ISD::STRICT_FREM:
4237     ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4238                     RTLIB::REM_F80, RTLIB::REM_F128,
4239                     RTLIB::REM_PPCF128, Results);
4240     break;
4241   case ISD::FMA:
4242   case ISD::STRICT_FMA:
4243     ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4244                     RTLIB::FMA_F80, RTLIB::FMA_F128,
4245                     RTLIB::FMA_PPCF128, Results);
4246     break;
4247   case ISD::FADD:
4248   case ISD::STRICT_FADD:
4249     ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4250                     RTLIB::ADD_F80, RTLIB::ADD_F128,
4251                     RTLIB::ADD_PPCF128, Results);
4252     break;
4253   case ISD::FMUL:
4254   case ISD::STRICT_FMUL:
4255     ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4256                     RTLIB::MUL_F80, RTLIB::MUL_F128,
4257                     RTLIB::MUL_PPCF128, Results);
4258     break;
4259   case ISD::FP16_TO_FP:
4260     if (Node->getValueType(0) == MVT::f32) {
4261       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4262     }
4263     break;
4264   case ISD::STRICT_FP16_TO_FP: {
4265     if (Node->getValueType(0) == MVT::f32) {
4266       TargetLowering::MakeLibCallOptions CallOptions;
4267       std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(
4268           DAG, RTLIB::FPEXT_F16_F32, MVT::f32, Node->getOperand(1), CallOptions,
4269           SDLoc(Node), Node->getOperand(0));
4270       Results.push_back(Tmp.first);
4271       Results.push_back(Tmp.second);
4272     }
4273     break;
4274   }
4275   case ISD::FP_TO_FP16: {
4276     RTLIB::Libcall LC =
4277         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4278     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4279     Results.push_back(ExpandLibCall(LC, Node, false));
4280     break;
4281   }
4282   case ISD::STRICT_FP_TO_FP16: {
4283     RTLIB::Libcall LC =
4284         RTLIB::getFPROUND(Node->getOperand(1).getValueType(), MVT::f16);
4285     assert(LC != RTLIB::UNKNOWN_LIBCALL &&
4286            "Unable to expand strict_fp_to_fp16");
4287     TargetLowering::MakeLibCallOptions CallOptions;
4288     std::pair<SDValue, SDValue> Tmp =
4289         TLI.makeLibCall(DAG, LC, Node->getValueType(0), Node->getOperand(1),
4290                         CallOptions, SDLoc(Node), Node->getOperand(0));
4291     Results.push_back(Tmp.first);
4292     Results.push_back(Tmp.second);
4293     break;
4294   }
4295   case ISD::FSUB:
4296   case ISD::STRICT_FSUB:
4297     ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4298                     RTLIB::SUB_F80, RTLIB::SUB_F128,
4299                     RTLIB::SUB_PPCF128, Results);
4300     break;
4301   case ISD::SREM:
4302     Results.push_back(ExpandIntLibCall(Node, true,
4303                                        RTLIB::SREM_I8,
4304                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4305                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4306     break;
4307   case ISD::UREM:
4308     Results.push_back(ExpandIntLibCall(Node, false,
4309                                        RTLIB::UREM_I8,
4310                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4311                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4312     break;
4313   case ISD::SDIV:
4314     Results.push_back(ExpandIntLibCall(Node, true,
4315                                        RTLIB::SDIV_I8,
4316                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4317                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4318     break;
4319   case ISD::UDIV:
4320     Results.push_back(ExpandIntLibCall(Node, false,
4321                                        RTLIB::UDIV_I8,
4322                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4323                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4324     break;
4325   case ISD::SDIVREM:
4326   case ISD::UDIVREM:
4327     // Expand into divrem libcall
4328     ExpandDivRemLibCall(Node, Results);
4329     break;
4330   case ISD::MUL:
4331     Results.push_back(ExpandIntLibCall(Node, false,
4332                                        RTLIB::MUL_I8,
4333                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4334                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4335     break;
4336   case ISD::CTLZ_ZERO_UNDEF:
4337     switch (Node->getSimpleValueType(0).SimpleTy) {
4338     default:
4339       llvm_unreachable("LibCall explicitly requested, but not available");
4340     case MVT::i32:
4341       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4342       break;
4343     case MVT::i64:
4344       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4345       break;
4346     case MVT::i128:
4347       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4348       break;
4349     }
4350     break;
4351   }
4352 
4353   // Replace the original node with the legalized result.
4354   if (!Results.empty()) {
4355     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4356     ReplaceNode(Node, Results.data());
4357   } else
4358     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4359 }
4360 
4361 // Determine the vector type to use in place of an original scalar element when
4362 // promoting equally sized vectors.
4363 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4364                                         MVT EltVT, MVT NewEltVT) {
4365   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4366   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4367   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4368   return MidVT;
4369 }
4370 
4371 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4372   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4373   SmallVector<SDValue, 8> Results;
4374   MVT OVT = Node->getSimpleValueType(0);
4375   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4376       Node->getOpcode() == ISD::SINT_TO_FP ||
4377       Node->getOpcode() == ISD::SETCC ||
4378       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4379       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4380     OVT = Node->getOperand(0).getSimpleValueType();
4381   }
4382   if (Node->getOpcode() == ISD::STRICT_UINT_TO_FP ||
4383       Node->getOpcode() == ISD::STRICT_SINT_TO_FP)
4384     OVT = Node->getOperand(1).getSimpleValueType();
4385   if (Node->getOpcode() == ISD::BR_CC)
4386     OVT = Node->getOperand(2).getSimpleValueType();
4387   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4388   SDLoc dl(Node);
4389   SDValue Tmp1, Tmp2, Tmp3;
4390   switch (Node->getOpcode()) {
4391   case ISD::CTTZ:
4392   case ISD::CTTZ_ZERO_UNDEF:
4393   case ISD::CTLZ:
4394   case ISD::CTLZ_ZERO_UNDEF:
4395   case ISD::CTPOP:
4396     // Zero extend the argument unless its cttz, then use any_extend.
4397     if (Node->getOpcode() == ISD::CTTZ ||
4398         Node->getOpcode() == ISD::CTTZ_ZERO_UNDEF)
4399       Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4400     else
4401       Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4402 
4403     if (Node->getOpcode() == ISD::CTTZ) {
4404       // The count is the same in the promoted type except if the original
4405       // value was zero.  This can be handled by setting the bit just off
4406       // the top of the original type.
4407       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4408                                         OVT.getSizeInBits());
4409       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4410                          DAG.getConstant(TopBit, dl, NVT));
4411     }
4412     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4413     // already the correct result.
4414     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4415     if (Node->getOpcode() == ISD::CTLZ ||
4416         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4417       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4418       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4419                           DAG.getConstant(NVT.getSizeInBits() -
4420                                           OVT.getSizeInBits(), dl, NVT));
4421     }
4422     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4423     break;
4424   case ISD::BITREVERSE:
4425   case ISD::BSWAP: {
4426     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4427     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4428     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4429     Tmp1 = DAG.getNode(
4430         ISD::SRL, dl, NVT, Tmp1,
4431         DAG.getConstant(DiffBits, dl,
4432                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4433 
4434     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4435     break;
4436   }
4437   case ISD::FP_TO_UINT:
4438   case ISD::STRICT_FP_TO_UINT:
4439   case ISD::FP_TO_SINT:
4440   case ISD::STRICT_FP_TO_SINT:
4441     PromoteLegalFP_TO_INT(Node, dl, Results);
4442     break;
4443   case ISD::UINT_TO_FP:
4444   case ISD::STRICT_UINT_TO_FP:
4445   case ISD::SINT_TO_FP:
4446   case ISD::STRICT_SINT_TO_FP:
4447     PromoteLegalINT_TO_FP(Node, dl, Results);
4448     break;
4449   case ISD::VAARG: {
4450     SDValue Chain = Node->getOperand(0); // Get the chain.
4451     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4452 
4453     unsigned TruncOp;
4454     if (OVT.isVector()) {
4455       TruncOp = ISD::BITCAST;
4456     } else {
4457       assert(OVT.isInteger()
4458         && "VAARG promotion is supported only for vectors or integer types");
4459       TruncOp = ISD::TRUNCATE;
4460     }
4461 
4462     // Perform the larger operation, then convert back
4463     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4464              Node->getConstantOperandVal(3));
4465     Chain = Tmp1.getValue(1);
4466 
4467     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4468 
4469     // Modified the chain result - switch anything that used the old chain to
4470     // use the new one.
4471     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4472     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4473     if (UpdatedNodes) {
4474       UpdatedNodes->insert(Tmp2.getNode());
4475       UpdatedNodes->insert(Chain.getNode());
4476     }
4477     ReplacedNode(Node);
4478     break;
4479   }
4480   case ISD::MUL:
4481   case ISD::SDIV:
4482   case ISD::SREM:
4483   case ISD::UDIV:
4484   case ISD::UREM:
4485   case ISD::AND:
4486   case ISD::OR:
4487   case ISD::XOR: {
4488     unsigned ExtOp, TruncOp;
4489     if (OVT.isVector()) {
4490       ExtOp   = ISD::BITCAST;
4491       TruncOp = ISD::BITCAST;
4492     } else {
4493       assert(OVT.isInteger() && "Cannot promote logic operation");
4494 
4495       switch (Node->getOpcode()) {
4496       default:
4497         ExtOp = ISD::ANY_EXTEND;
4498         break;
4499       case ISD::SDIV:
4500       case ISD::SREM:
4501         ExtOp = ISD::SIGN_EXTEND;
4502         break;
4503       case ISD::UDIV:
4504       case ISD::UREM:
4505         ExtOp = ISD::ZERO_EXTEND;
4506         break;
4507       }
4508       TruncOp = ISD::TRUNCATE;
4509     }
4510     // Promote each of the values to the new type.
4511     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4512     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4513     // Perform the larger operation, then convert back
4514     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4515     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4516     break;
4517   }
4518   case ISD::UMUL_LOHI:
4519   case ISD::SMUL_LOHI: {
4520     // Promote to a multiply in a wider integer type.
4521     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4522                                                          : ISD::SIGN_EXTEND;
4523     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4524     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4525     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4526 
4527     auto &DL = DAG.getDataLayout();
4528     unsigned OriginalSize = OVT.getScalarSizeInBits();
4529     Tmp2 = DAG.getNode(
4530         ISD::SRL, dl, NVT, Tmp1,
4531         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4532     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4533     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4534     break;
4535   }
4536   case ISD::SELECT: {
4537     unsigned ExtOp, TruncOp;
4538     if (Node->getValueType(0).isVector() ||
4539         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4540       ExtOp   = ISD::BITCAST;
4541       TruncOp = ISD::BITCAST;
4542     } else if (Node->getValueType(0).isInteger()) {
4543       ExtOp   = ISD::ANY_EXTEND;
4544       TruncOp = ISD::TRUNCATE;
4545     } else {
4546       ExtOp   = ISD::FP_EXTEND;
4547       TruncOp = ISD::FP_ROUND;
4548     }
4549     Tmp1 = Node->getOperand(0);
4550     // Promote each of the values to the new type.
4551     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4552     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4553     // Perform the larger operation, then round down.
4554     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4555     Tmp1->setFlags(Node->getFlags());
4556     if (TruncOp != ISD::FP_ROUND)
4557       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4558     else
4559       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4560                          DAG.getIntPtrConstant(0, dl));
4561     Results.push_back(Tmp1);
4562     break;
4563   }
4564   case ISD::VECTOR_SHUFFLE: {
4565     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4566 
4567     // Cast the two input vectors.
4568     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4569     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4570 
4571     // Convert the shuffle mask to the right # elements.
4572     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4573     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4574     Results.push_back(Tmp1);
4575     break;
4576   }
4577   case ISD::SETCC: {
4578     unsigned ExtOp = ISD::FP_EXTEND;
4579     if (NVT.isInteger()) {
4580       ISD::CondCode CCCode =
4581         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4582       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4583     }
4584     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4585     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4586     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0), Tmp1,
4587                                   Tmp2, Node->getOperand(2), Node->getFlags()));
4588     break;
4589   }
4590   case ISD::BR_CC: {
4591     unsigned ExtOp = ISD::FP_EXTEND;
4592     if (NVT.isInteger()) {
4593       ISD::CondCode CCCode =
4594         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4595       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4596     }
4597     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4598     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4599     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4600                                   Node->getOperand(0), Node->getOperand(1),
4601                                   Tmp1, Tmp2, Node->getOperand(4)));
4602     break;
4603   }
4604   case ISD::FADD:
4605   case ISD::FSUB:
4606   case ISD::FMUL:
4607   case ISD::FDIV:
4608   case ISD::FREM:
4609   case ISD::FMINNUM:
4610   case ISD::FMAXNUM:
4611   case ISD::FPOW:
4612     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4613     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4614     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4615                        Node->getFlags());
4616     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4617                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4618     break;
4619   case ISD::STRICT_FREM:
4620   case ISD::STRICT_FPOW:
4621     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4622                        {Node->getOperand(0), Node->getOperand(1)});
4623     Tmp2 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4624                        {Node->getOperand(0), Node->getOperand(2)});
4625     Tmp3 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Tmp1.getValue(1),
4626                        Tmp2.getValue(1));
4627     Tmp1 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4628                        {Tmp3, Tmp1, Tmp2});
4629     Tmp1 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4630                        {Tmp1.getValue(1), Tmp1, DAG.getIntPtrConstant(0, dl)});
4631     Results.push_back(Tmp1);
4632     Results.push_back(Tmp1.getValue(1));
4633     break;
4634   case ISD::FMA:
4635     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4636     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4637     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4638     Results.push_back(
4639         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4640                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4641                     DAG.getIntPtrConstant(0, dl)));
4642     break;
4643   case ISD::FCOPYSIGN:
4644   case ISD::FPOWI: {
4645     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4646     Tmp2 = Node->getOperand(1);
4647     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4648 
4649     // fcopysign doesn't change anything but the sign bit, so
4650     //   (fp_round (fcopysign (fpext a), b))
4651     // is as precise as
4652     //   (fp_round (fpext a))
4653     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4654     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4655     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4656                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4657     break;
4658   }
4659   case ISD::FFLOOR:
4660   case ISD::FCEIL:
4661   case ISD::FRINT:
4662   case ISD::FNEARBYINT:
4663   case ISD::FROUND:
4664   case ISD::FROUNDEVEN:
4665   case ISD::FTRUNC:
4666   case ISD::FNEG:
4667   case ISD::FSQRT:
4668   case ISD::FSIN:
4669   case ISD::FCOS:
4670   case ISD::FLOG:
4671   case ISD::FLOG2:
4672   case ISD::FLOG10:
4673   case ISD::FABS:
4674   case ISD::FEXP:
4675   case ISD::FEXP2:
4676     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4677     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4678     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4679                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4680     break;
4681   case ISD::STRICT_FFLOOR:
4682   case ISD::STRICT_FCEIL:
4683   case ISD::STRICT_FSIN:
4684   case ISD::STRICT_FCOS:
4685   case ISD::STRICT_FLOG:
4686   case ISD::STRICT_FLOG10:
4687   case ISD::STRICT_FEXP:
4688     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4689                        {Node->getOperand(0), Node->getOperand(1)});
4690     Tmp2 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4691                        {Tmp1.getValue(1), Tmp1});
4692     Tmp3 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4693                        {Tmp2.getValue(1), Tmp2, DAG.getIntPtrConstant(0, dl)});
4694     Results.push_back(Tmp3);
4695     Results.push_back(Tmp3.getValue(1));
4696     break;
4697   case ISD::BUILD_VECTOR: {
4698     MVT EltVT = OVT.getVectorElementType();
4699     MVT NewEltVT = NVT.getVectorElementType();
4700 
4701     // Handle bitcasts to a different vector type with the same total bit size
4702     //
4703     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4704     //  =>
4705     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4706 
4707     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4708            "Invalid promote type for build_vector");
4709     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4710 
4711     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4712 
4713     SmallVector<SDValue, 8> NewOps;
4714     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4715       SDValue Op = Node->getOperand(I);
4716       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4717     }
4718 
4719     SDLoc SL(Node);
4720     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4721     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4722     Results.push_back(CvtVec);
4723     break;
4724   }
4725   case ISD::EXTRACT_VECTOR_ELT: {
4726     MVT EltVT = OVT.getVectorElementType();
4727     MVT NewEltVT = NVT.getVectorElementType();
4728 
4729     // Handle bitcasts to a different vector type with the same total bit size.
4730     //
4731     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4732     //  =>
4733     //  v4i32:castx = bitcast x:v2i64
4734     //
4735     // i64 = bitcast
4736     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4737     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4738     //
4739 
4740     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4741            "Invalid promote type for extract_vector_elt");
4742     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4743 
4744     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4745     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4746 
4747     SDValue Idx = Node->getOperand(1);
4748     EVT IdxVT = Idx.getValueType();
4749     SDLoc SL(Node);
4750     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4751     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4752 
4753     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4754 
4755     SmallVector<SDValue, 8> NewOps;
4756     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4757       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4758       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4759 
4760       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4761                                 CastVec, TmpIdx);
4762       NewOps.push_back(Elt);
4763     }
4764 
4765     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4766     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4767     break;
4768   }
4769   case ISD::INSERT_VECTOR_ELT: {
4770     MVT EltVT = OVT.getVectorElementType();
4771     MVT NewEltVT = NVT.getVectorElementType();
4772 
4773     // Handle bitcasts to a different vector type with the same total bit size
4774     //
4775     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4776     //  =>
4777     //  v4i32:castx = bitcast x:v2i64
4778     //  v2i32:casty = bitcast y:i64
4779     //
4780     // v2i64 = bitcast
4781     //   (v4i32 insert_vector_elt
4782     //       (v4i32 insert_vector_elt v4i32:castx,
4783     //                                (extract_vector_elt casty, 0), 2 * z),
4784     //        (extract_vector_elt casty, 1), (2 * z + 1))
4785 
4786     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4787            "Invalid promote type for insert_vector_elt");
4788     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4789 
4790     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4791     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4792 
4793     SDValue Val = Node->getOperand(1);
4794     SDValue Idx = Node->getOperand(2);
4795     EVT IdxVT = Idx.getValueType();
4796     SDLoc SL(Node);
4797 
4798     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4799     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4800 
4801     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4802     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4803 
4804     SDValue NewVec = CastVec;
4805     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4806       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4807       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4808 
4809       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4810                                 CastVal, IdxOffset);
4811 
4812       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4813                            NewVec, Elt, InEltIdx);
4814     }
4815 
4816     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4817     break;
4818   }
4819   case ISD::SCALAR_TO_VECTOR: {
4820     MVT EltVT = OVT.getVectorElementType();
4821     MVT NewEltVT = NVT.getVectorElementType();
4822 
4823     // Handle bitcasts to different vector type with the same total bit size.
4824     //
4825     // e.g. v2i64 = scalar_to_vector x:i64
4826     //   =>
4827     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4828     //
4829 
4830     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4831     SDValue Val = Node->getOperand(0);
4832     SDLoc SL(Node);
4833 
4834     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4835     SDValue Undef = DAG.getUNDEF(MidVT);
4836 
4837     SmallVector<SDValue, 8> NewElts;
4838     NewElts.push_back(CastVal);
4839     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4840       NewElts.push_back(Undef);
4841 
4842     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4843     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4844     Results.push_back(CvtVec);
4845     break;
4846   }
4847   case ISD::ATOMIC_SWAP: {
4848     AtomicSDNode *AM = cast<AtomicSDNode>(Node);
4849     SDLoc SL(Node);
4850     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NVT, AM->getVal());
4851     assert(NVT.getSizeInBits() == OVT.getSizeInBits() &&
4852            "unexpected promotion type");
4853     assert(AM->getMemoryVT().getSizeInBits() == NVT.getSizeInBits() &&
4854            "unexpected atomic_swap with illegal type");
4855 
4856     SDValue NewAtomic
4857       = DAG.getAtomic(ISD::ATOMIC_SWAP, SL, NVT,
4858                       DAG.getVTList(NVT, MVT::Other),
4859                       { AM->getChain(), AM->getBasePtr(), CastVal },
4860                       AM->getMemOperand());
4861     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewAtomic));
4862     Results.push_back(NewAtomic.getValue(1));
4863     break;
4864   }
4865   }
4866 
4867   // Replace the original node with the legalized result.
4868   if (!Results.empty()) {
4869     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4870     ReplaceNode(Node, Results.data());
4871   } else
4872     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4873 }
4874 
4875 /// This is the entry point for the file.
4876 void SelectionDAG::Legalize() {
4877   AssignTopologicalOrder();
4878 
4879   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4880   // Use a delete listener to remove nodes which were deleted during
4881   // legalization from LegalizeNodes. This is needed to handle the situation
4882   // where a new node is allocated by the object pool to the same address of a
4883   // previously deleted node.
4884   DAGNodeDeletedListener DeleteListener(
4885       *this,
4886       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4887 
4888   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4889 
4890   // Visit all the nodes. We start in topological order, so that we see
4891   // nodes with their original operands intact. Legalization can produce
4892   // new nodes which may themselves need to be legalized. Iterate until all
4893   // nodes have been legalized.
4894   while (true) {
4895     bool AnyLegalized = false;
4896     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4897       --NI;
4898 
4899       SDNode *N = &*NI;
4900       if (N->use_empty() && N != getRoot().getNode()) {
4901         ++NI;
4902         DeleteNode(N);
4903         continue;
4904       }
4905 
4906       if (LegalizedNodes.insert(N).second) {
4907         AnyLegalized = true;
4908         Legalizer.LegalizeOp(N);
4909 
4910         if (N->use_empty() && N != getRoot().getNode()) {
4911           ++NI;
4912           DeleteNode(N);
4913         }
4914       }
4915     }
4916     if (!AnyLegalized)
4917       break;
4918 
4919   }
4920 
4921   // Remove dead nodes now.
4922   RemoveDeadNodes();
4923 }
4924 
4925 bool SelectionDAG::LegalizeOp(SDNode *N,
4926                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4927   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4928   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4929 
4930   // Directly insert the node in question, and legalize it. This will recurse
4931   // as needed through operands.
4932   LegalizedNodes.insert(N);
4933   Legalizer.LegalizeOp(N);
4934 
4935   return LegalizedNodes.count(N);
4936 }
4937