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/FloatingPointMode.h"
17 #include "llvm/ADT/SetVector.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/SmallSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/Analysis/TargetLibraryInfo.h"
22 #include "llvm/CodeGen/ISDOpcodes.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineJumpTableInfo.h"
25 #include "llvm/CodeGen/MachineMemOperand.h"
26 #include "llvm/CodeGen/RuntimeLibcalls.h"
27 #include "llvm/CodeGen/SelectionDAG.h"
28 #include "llvm/CodeGen/SelectionDAGNodes.h"
29 #include "llvm/CodeGen/TargetFrameLowering.h"
30 #include "llvm/CodeGen/TargetLowering.h"
31 #include "llvm/CodeGen/TargetSubtargetInfo.h"
32 #include "llvm/CodeGen/ValueTypes.h"
33 #include "llvm/IR/CallingConv.h"
34 #include "llvm/IR/Constants.h"
35 #include "llvm/IR/DataLayout.h"
36 #include "llvm/IR/DerivedTypes.h"
37 #include "llvm/IR/Function.h"
38 #include "llvm/IR/Metadata.h"
39 #include "llvm/IR/Type.h"
40 #include "llvm/Support/Casting.h"
41 #include "llvm/Support/Compiler.h"
42 #include "llvm/Support/Debug.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/MachineValueType.h"
45 #include "llvm/Support/MathExtras.h"
46 #include "llvm/Support/raw_ostream.h"
47 #include "llvm/Target/TargetMachine.h"
48 #include "llvm/Target/TargetOptions.h"
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
137 
138   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall LC,
139                        SmallVectorImpl<SDValue> &Results);
140   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
141                        RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
142                        RTLIB::Libcall Call_F128,
143                        RTLIB::Libcall Call_PPCF128,
144                        SmallVectorImpl<SDValue> &Results);
145   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned, RTLIB::Libcall Call_I8,
146                            RTLIB::Libcall Call_I16, RTLIB::Libcall Call_I32,
147                            RTLIB::Libcall Call_I64, RTLIB::Libcall Call_I128,
148                            RTLIB::Libcall Call_IEXT);
149   void ExpandArgFPLibCall(SDNode *Node,
150                           RTLIB::Libcall Call_F32, RTLIB::Libcall Call_F64,
151                           RTLIB::Libcall Call_F80, RTLIB::Libcall Call_F128,
152                           RTLIB::Libcall Call_PPCF128,
153                           SmallVectorImpl<SDValue> &Results);
154   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
155   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
156 
157   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
158                            const SDLoc &dl);
159   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
160                            const SDLoc &dl, SDValue ChainIn);
161   SDValue ExpandBUILD_VECTOR(SDNode *Node);
162   SDValue ExpandSPLAT_VECTOR(SDNode *Node);
163   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
164   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
165                                 SmallVectorImpl<SDValue> &Results);
166   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
167                          SDValue Value) const;
168   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
169                           SDValue NewIntValue) const;
170   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
171   SDValue ExpandFABS(SDNode *Node) const;
172   SDValue ExpandFNEG(SDNode *Node) const;
173   SDValue ExpandLegalINT_TO_FP(SDNode *Node, SDValue &Chain);
174   void PromoteLegalINT_TO_FP(SDNode *N, const SDLoc &dl,
175                              SmallVectorImpl<SDValue> &Results);
176   void PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
177                              SmallVectorImpl<SDValue> &Results);
178   SDValue PromoteLegalFP_TO_INT_SAT(SDNode *Node, const SDLoc &dl);
179 
180   SDValue ExpandPARITY(SDValue Op, const SDLoc &dl);
181 
182   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
183   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
184   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
185 
186   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
187   SDValue ExpandConstant(ConstantSDNode *CP);
188 
189   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
190   bool ExpandNode(SDNode *Node);
191   void ConvertNodeToLibcall(SDNode *Node);
192   void PromoteNode(SDNode *Node);
193 
194 public:
195   // Node replacement helpers
196 
197   void ReplacedNode(SDNode *N) {
198     LegalizedNodes.erase(N);
199     if (UpdatedNodes)
200       UpdatedNodes->insert(N);
201   }
202 
203   void ReplaceNode(SDNode *Old, SDNode *New) {
204     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
205                dbgs() << "     with:      "; New->dump(&DAG));
206 
207     assert(Old->getNumValues() == New->getNumValues() &&
208            "Replacing one node with another that produces a different number "
209            "of values!");
210     DAG.ReplaceAllUsesWith(Old, New);
211     if (UpdatedNodes)
212       UpdatedNodes->insert(New);
213     ReplacedNode(Old);
214   }
215 
216   void ReplaceNode(SDValue Old, SDValue New) {
217     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
218                dbgs() << "     with:      "; New->dump(&DAG));
219 
220     DAG.ReplaceAllUsesWith(Old, New);
221     if (UpdatedNodes)
222       UpdatedNodes->insert(New.getNode());
223     ReplacedNode(Old.getNode());
224   }
225 
226   void ReplaceNode(SDNode *Old, const SDValue *New) {
227     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
228 
229     DAG.ReplaceAllUsesWith(Old, New);
230     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
231       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
232                  New[i]->dump(&DAG));
233       if (UpdatedNodes)
234         UpdatedNodes->insert(New[i].getNode());
235     }
236     ReplacedNode(Old);
237   }
238 
239   void ReplaceNodeWithValue(SDValue Old, SDValue New) {
240     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
241                dbgs() << "     with:      "; New->dump(&DAG));
242 
243     DAG.ReplaceAllUsesOfValueWith(Old, New);
244     if (UpdatedNodes)
245       UpdatedNodes->insert(New.getNode());
246     ReplacedNode(Old.getNode());
247   }
248 };
249 
250 } // end anonymous namespace
251 
252 /// Return a vector shuffle operation which
253 /// performs the same shuffle in terms of order or result bytes, but on a type
254 /// whose vector element type is narrower than the original shuffle type.
255 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
256 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
257     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
258     ArrayRef<int> Mask) const {
259   unsigned NumMaskElts = VT.getVectorNumElements();
260   unsigned NumDestElts = NVT.getVectorNumElements();
261   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
262 
263   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
264 
265   if (NumEltsGrowth == 1)
266     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
267 
268   SmallVector<int, 8> NewMask;
269   for (unsigned i = 0; i != NumMaskElts; ++i) {
270     int Idx = Mask[i];
271     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
272       if (Idx < 0)
273         NewMask.push_back(-1);
274       else
275         NewMask.push_back(Idx * NumEltsGrowth + j);
276     }
277   }
278   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
279   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
280   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
281 }
282 
283 /// Expands the ConstantFP node to an integer constant or
284 /// a load from the constant pool.
285 SDValue
286 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
287   bool Extend = false;
288   SDLoc dl(CFP);
289 
290   // If a FP immediate is precise when represented as a float and if the
291   // target can do an extending load from float to double, we put it into
292   // the constant pool as a float, even if it's is statically typed as a
293   // double.  This shrinks FP constants and canonicalizes them for targets where
294   // an FP extending load is the same cost as a normal load (such as on the x87
295   // fp stack or PPC FP unit).
296   EVT VT = CFP->getValueType(0);
297   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
298   if (!UseCP) {
299     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
300     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
301                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
302   }
303 
304   APFloat APF = CFP->getValueAPF();
305   EVT OrigVT = VT;
306   EVT SVT = VT;
307 
308   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
309   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
310   if (!APF.isSignaling()) {
311     while (SVT != MVT::f32 && SVT != MVT::f16) {
312       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
313       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
314           // Only do this if the target has a native EXTLOAD instruction from
315           // smaller type.
316           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
317           TLI.ShouldShrinkFPConstant(OrigVT)) {
318         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
319         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
320         VT = SVT;
321         Extend = true;
322       }
323     }
324   }
325 
326   SDValue CPIdx =
327       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
328   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
329   if (Extend) {
330     SDValue Result = DAG.getExtLoad(
331         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
332         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
333         Alignment);
334     return Result;
335   }
336   SDValue Result = DAG.getLoad(
337       OrigVT, dl, DAG.getEntryNode(), CPIdx,
338       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
339   return Result;
340 }
341 
342 /// Expands the Constant node to a load from the constant pool.
343 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
344   SDLoc dl(CP);
345   EVT VT = CP->getValueType(0);
346   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
347                                       TLI.getPointerTy(DAG.getDataLayout()));
348   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
349   SDValue Result = DAG.getLoad(
350       VT, dl, DAG.getEntryNode(), CPIdx,
351       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
352   return Result;
353 }
354 
355 /// Some target cannot handle a variable insertion index for the
356 /// INSERT_VECTOR_ELT instruction.  In this case, it
357 /// is necessary to spill the vector being inserted into to memory, perform
358 /// the insert there, and then read the result back.
359 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
360                                                              SDValue Val,
361                                                              SDValue Idx,
362                                                              const SDLoc &dl) {
363   SDValue Tmp1 = Vec;
364   SDValue Tmp2 = Val;
365   SDValue Tmp3 = Idx;
366 
367   // If the target doesn't support this, we have to spill the input vector
368   // to a temporary stack slot, update the element, then reload it.  This is
369   // badness.  We could also load the value into a vector register (either
370   // with a "move to register" or "extload into register" instruction, then
371   // permute it into place, if the idx is a constant and if the idx is
372   // supported by the target.
373   EVT VT    = Tmp1.getValueType();
374   EVT EltVT = VT.getVectorElementType();
375   SDValue StackPtr = DAG.CreateStackTemporary(VT);
376 
377   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
378 
379   // Store the vector.
380   SDValue Ch = DAG.getStore(
381       DAG.getEntryNode(), dl, Tmp1, StackPtr,
382       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
383 
384   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
385 
386   // Store the scalar value.
387   Ch = DAG.getTruncStore(
388       Ch, dl, Tmp2, StackPtr2,
389       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()), EltVT);
390   // Load the updated vector.
391   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
392                                                DAG.getMachineFunction(), SPFI));
393 }
394 
395 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
396                                                       SDValue Idx,
397                                                       const SDLoc &dl) {
398   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
399     // SCALAR_TO_VECTOR requires that the type of the value being inserted
400     // match the element type of the vector being created, except for
401     // integers in which case the inserted value can be over width.
402     EVT EltVT = Vec.getValueType().getVectorElementType();
403     if (Val.getValueType() == EltVT ||
404         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
405       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
406                                   Vec.getValueType(), Val);
407 
408       unsigned NumElts = Vec.getValueType().getVectorNumElements();
409       // We generate a shuffle of InVec and ScVec, so the shuffle mask
410       // should be 0,1,2,3,4,5... with the appropriate element replaced with
411       // elt 0 of the RHS.
412       SmallVector<int, 8> ShufOps;
413       for (unsigned i = 0; i != NumElts; ++i)
414         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
415 
416       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
417     }
418   }
419   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
420 }
421 
422 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
423   if (!ISD::isNormalStore(ST))
424     return SDValue();
425 
426   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
427   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
428   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
429   // to phase ordering between legalized code and the dag combiner.  This
430   // probably means that we need to integrate dag combiner and legalizer
431   // together.
432   // We generally can't do this one for long doubles.
433   SDValue Chain = ST->getChain();
434   SDValue Ptr = ST->getBasePtr();
435   SDValue Value = ST->getValue();
436   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
437   AAMDNodes AAInfo = ST->getAAInfo();
438   SDLoc dl(ST);
439 
440   // Don't optimise TargetConstantFP
441   if (Value.getOpcode() == ISD::TargetConstantFP)
442     return SDValue();
443 
444   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
445     if (CFP->getValueType(0) == MVT::f32 &&
446         TLI.isTypeLegal(MVT::i32)) {
447       SDValue Con = DAG.getConstant(CFP->getValueAPF().
448                                       bitcastToAPInt().zextOrTrunc(32),
449                                     SDLoc(CFP), MVT::i32);
450       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
451                           ST->getOriginalAlign(), MMOFlags, AAInfo);
452     }
453 
454     if (CFP->getValueType(0) == MVT::f64) {
455       // If this target supports 64-bit registers, do a single 64-bit store.
456       if (TLI.isTypeLegal(MVT::i64)) {
457         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
458                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
459         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
460                             ST->getOriginalAlign(), MMOFlags, AAInfo);
461       }
462 
463       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
464         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
465         // stores.  If the target supports neither 32- nor 64-bits, this
466         // xform is certainly not worth it.
467         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
468         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
469         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
470         if (DAG.getDataLayout().isBigEndian())
471           std::swap(Lo, Hi);
472 
473         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(),
474                           ST->getOriginalAlign(), MMOFlags, AAInfo);
475         Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(4), dl);
476         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
477                           ST->getPointerInfo().getWithOffset(4),
478                           ST->getOriginalAlign(), MMOFlags, AAInfo);
479 
480         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
481       }
482     }
483   }
484   return SDValue();
485 }
486 
487 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
488   StoreSDNode *ST = cast<StoreSDNode>(Node);
489   SDValue Chain = ST->getChain();
490   SDValue Ptr = ST->getBasePtr();
491   SDLoc dl(Node);
492 
493   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
494   AAMDNodes AAInfo = ST->getAAInfo();
495 
496   if (!ST->isTruncatingStore()) {
497     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
498     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
499       ReplaceNode(ST, OptStore);
500       return;
501     }
502 
503     SDValue Value = ST->getValue();
504     MVT VT = Value.getSimpleValueType();
505     switch (TLI.getOperationAction(ISD::STORE, VT)) {
506     default: llvm_unreachable("This action is not supported yet!");
507     case TargetLowering::Legal: {
508       // If this is an unaligned store and the target doesn't support it,
509       // expand it.
510       EVT MemVT = ST->getMemoryVT();
511       const DataLayout &DL = DAG.getDataLayout();
512       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
513                                               *ST->getMemOperand())) {
514         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
515         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
516         ReplaceNode(SDValue(ST, 0), Result);
517       } else
518         LLVM_DEBUG(dbgs() << "Legal store\n");
519       break;
520     }
521     case TargetLowering::Custom: {
522       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
523       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
524       if (Res && Res != SDValue(Node, 0))
525         ReplaceNode(SDValue(Node, 0), Res);
526       return;
527     }
528     case TargetLowering::Promote: {
529       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
530       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
531              "Can only promote stores to same size type");
532       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
533       SDValue Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
534                                     ST->getOriginalAlign(), MMOFlags, AAInfo);
535       ReplaceNode(SDValue(Node, 0), Result);
536       break;
537     }
538     }
539     return;
540   }
541 
542   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
543   SDValue Value = ST->getValue();
544   EVT StVT = ST->getMemoryVT();
545   TypeSize StWidth = StVT.getSizeInBits();
546   TypeSize StSize = StVT.getStoreSizeInBits();
547   auto &DL = DAG.getDataLayout();
548 
549   if (StWidth != StSize) {
550     // Promote to a byte-sized store with upper bits zero if not
551     // storing an integral number of bytes.  For example, promote
552     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
553     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), StSize.getFixedSize());
554     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
555     SDValue Result =
556         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
557                           ST->getOriginalAlign(), MMOFlags, AAInfo);
558     ReplaceNode(SDValue(Node, 0), Result);
559   } else if (!StVT.isVector() && !isPowerOf2_64(StWidth.getFixedSize())) {
560     // If not storing a power-of-2 number of bits, expand as two stores.
561     assert(!StVT.isVector() && "Unsupported truncstore!");
562     unsigned StWidthBits = StWidth.getFixedSize();
563     unsigned LogStWidth = Log2_32(StWidthBits);
564     assert(LogStWidth < 32);
565     unsigned RoundWidth = 1 << LogStWidth;
566     assert(RoundWidth < StWidthBits);
567     unsigned ExtraWidth = StWidthBits - RoundWidth;
568     assert(ExtraWidth < RoundWidth);
569     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
570            "Store size not an integral number of bytes!");
571     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
572     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
573     SDValue Lo, Hi;
574     unsigned IncrementSize;
575 
576     if (DL.isLittleEndian()) {
577       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
578       // Store the bottom RoundWidth bits.
579       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
580                              RoundVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
581 
582       // Store the remaining ExtraWidth bits.
583       IncrementSize = RoundWidth / 8;
584       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
585       Hi = DAG.getNode(
586           ISD::SRL, dl, Value.getValueType(), Value,
587           DAG.getConstant(RoundWidth, dl,
588                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
589       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
590                              ST->getPointerInfo().getWithOffset(IncrementSize),
591                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
592     } else {
593       // Big endian - avoid unaligned stores.
594       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
595       // Store the top RoundWidth bits.
596       Hi = DAG.getNode(
597           ISD::SRL, dl, Value.getValueType(), Value,
598           DAG.getConstant(ExtraWidth, dl,
599                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
600       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(), RoundVT,
601                              ST->getOriginalAlign(), MMOFlags, AAInfo);
602 
603       // Store the remaining ExtraWidth bits.
604       IncrementSize = RoundWidth / 8;
605       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
606                         DAG.getConstant(IncrementSize, dl,
607                                         Ptr.getValueType()));
608       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
609                              ST->getPointerInfo().getWithOffset(IncrementSize),
610                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
611     }
612 
613     // The order of the stores doesn't matter.
614     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
615     ReplaceNode(SDValue(Node, 0), Result);
616   } else {
617     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
618     default: llvm_unreachable("This action is not supported yet!");
619     case TargetLowering::Legal: {
620       EVT MemVT = ST->getMemoryVT();
621       // If this is an unaligned store and the target doesn't support it,
622       // expand it.
623       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
624                                               *ST->getMemOperand())) {
625         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
626         ReplaceNode(SDValue(ST, 0), Result);
627       }
628       break;
629     }
630     case TargetLowering::Custom: {
631       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
632       if (Res && Res != SDValue(Node, 0))
633         ReplaceNode(SDValue(Node, 0), Res);
634       return;
635     }
636     case TargetLowering::Expand:
637       assert(!StVT.isVector() &&
638              "Vector Stores are handled in LegalizeVectorOps");
639 
640       SDValue Result;
641 
642       // TRUNCSTORE:i16 i32 -> STORE i16
643       if (TLI.isTypeLegal(StVT)) {
644         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
645         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
646                               ST->getOriginalAlign(), MMOFlags, AAInfo);
647       } else {
648         // The in-memory type isn't legal. Truncate to the type it would promote
649         // to, and then do a truncstore.
650         Value = DAG.getNode(ISD::TRUNCATE, dl,
651                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
652                             Value);
653         Result =
654             DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), StVT,
655                               ST->getOriginalAlign(), MMOFlags, AAInfo);
656       }
657 
658       ReplaceNode(SDValue(Node, 0), Result);
659       break;
660     }
661   }
662 }
663 
664 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
665   LoadSDNode *LD = cast<LoadSDNode>(Node);
666   SDValue Chain = LD->getChain();  // The chain.
667   SDValue Ptr = LD->getBasePtr();  // The base pointer.
668   SDValue Value;                   // The value returned by the load op.
669   SDLoc dl(Node);
670 
671   ISD::LoadExtType ExtType = LD->getExtensionType();
672   if (ExtType == ISD::NON_EXTLOAD) {
673     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
674     MVT VT = Node->getSimpleValueType(0);
675     SDValue RVal = SDValue(Node, 0);
676     SDValue RChain = SDValue(Node, 1);
677 
678     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
679     default: llvm_unreachable("This action is not supported yet!");
680     case TargetLowering::Legal: {
681       EVT MemVT = LD->getMemoryVT();
682       const DataLayout &DL = DAG.getDataLayout();
683       // If this is an unaligned load and the target doesn't support it,
684       // expand it.
685       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
686                                               *LD->getMemOperand())) {
687         std::tie(RVal, RChain) = TLI.expandUnalignedLoad(LD, DAG);
688       }
689       break;
690     }
691     case TargetLowering::Custom:
692       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
693         RVal = Res;
694         RChain = Res.getValue(1);
695       }
696       break;
697 
698     case TargetLowering::Promote: {
699       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
700       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
701              "Can only promote loads to same size type");
702 
703       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
704       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
705       RChain = Res.getValue(1);
706       break;
707     }
708     }
709     if (RChain.getNode() != Node) {
710       assert(RVal.getNode() != Node && "Load must be completely replaced");
711       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
712       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
713       if (UpdatedNodes) {
714         UpdatedNodes->insert(RVal.getNode());
715         UpdatedNodes->insert(RChain.getNode());
716       }
717       ReplacedNode(Node);
718     }
719     return;
720   }
721 
722   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
723   EVT SrcVT = LD->getMemoryVT();
724   TypeSize SrcWidth = SrcVT.getSizeInBits();
725   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
726   AAMDNodes AAInfo = LD->getAAInfo();
727 
728   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
729       // Some targets pretend to have an i1 loading operation, and actually
730       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
731       // bits are guaranteed to be zero; it helps the optimizers understand
732       // that these bits are zero.  It is also useful for EXTLOAD, since it
733       // tells the optimizers that those bits are undefined.  It would be
734       // nice to have an effective generic way of getting these benefits...
735       // Until such a way is found, don't insist on promoting i1 here.
736       (SrcVT != MVT::i1 ||
737        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
738          TargetLowering::Promote)) {
739     // Promote to a byte-sized load if not loading an integral number of
740     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
741     unsigned NewWidth = SrcVT.getStoreSizeInBits();
742     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
743     SDValue Ch;
744 
745     // The extra bits are guaranteed to be zero, since we stored them that
746     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
747 
748     ISD::LoadExtType NewExtType =
749       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
750 
751     SDValue Result = DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
752                                     Chain, Ptr, LD->getPointerInfo(), NVT,
753                                     LD->getOriginalAlign(), MMOFlags, AAInfo);
754 
755     Ch = Result.getValue(1); // The chain.
756 
757     if (ExtType == ISD::SEXTLOAD)
758       // Having the top bits zero doesn't help when sign extending.
759       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
760                            Result.getValueType(),
761                            Result, DAG.getValueType(SrcVT));
762     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
763       // All the top bits are guaranteed to be zero - inform the optimizers.
764       Result = DAG.getNode(ISD::AssertZext, dl,
765                            Result.getValueType(), Result,
766                            DAG.getValueType(SrcVT));
767 
768     Value = Result;
769     Chain = Ch;
770   } else if (!isPowerOf2_64(SrcWidth.getKnownMinSize())) {
771     // If not loading a power-of-2 number of bits, expand as two loads.
772     assert(!SrcVT.isVector() && "Unsupported extload!");
773     unsigned SrcWidthBits = SrcWidth.getFixedSize();
774     unsigned LogSrcWidth = Log2_32(SrcWidthBits);
775     assert(LogSrcWidth < 32);
776     unsigned RoundWidth = 1 << LogSrcWidth;
777     assert(RoundWidth < SrcWidthBits);
778     unsigned ExtraWidth = SrcWidthBits - RoundWidth;
779     assert(ExtraWidth < RoundWidth);
780     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
781            "Load size not an integral number of bytes!");
782     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
783     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
784     SDValue Lo, Hi, Ch;
785     unsigned IncrementSize;
786     auto &DL = DAG.getDataLayout();
787 
788     if (DL.isLittleEndian()) {
789       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
790       // Load the bottom RoundWidth bits.
791       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
792                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
793                           MMOFlags, AAInfo);
794 
795       // Load the remaining ExtraWidth bits.
796       IncrementSize = RoundWidth / 8;
797       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
798       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
799                           LD->getPointerInfo().getWithOffset(IncrementSize),
800                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
801 
802       // Build a factor node to remember that this load is independent of
803       // the other one.
804       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
805                        Hi.getValue(1));
806 
807       // Move the top bits to the right place.
808       Hi = DAG.getNode(
809           ISD::SHL, dl, Hi.getValueType(), Hi,
810           DAG.getConstant(RoundWidth, dl,
811                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
812 
813       // Join the hi and lo parts.
814       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
815     } else {
816       // Big endian - avoid unaligned loads.
817       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
818       // Load the top RoundWidth bits.
819       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
820                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
821                           MMOFlags, AAInfo);
822 
823       // Load the remaining ExtraWidth bits.
824       IncrementSize = RoundWidth / 8;
825       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
826       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
827                           LD->getPointerInfo().getWithOffset(IncrementSize),
828                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
829 
830       // Build a factor node to remember that this load is independent of
831       // the other one.
832       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
833                        Hi.getValue(1));
834 
835       // Move the top bits to the right place.
836       Hi = DAG.getNode(
837           ISD::SHL, dl, Hi.getValueType(), Hi,
838           DAG.getConstant(ExtraWidth, dl,
839                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
840 
841       // Join the hi and lo parts.
842       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
843     }
844 
845     Chain = Ch;
846   } else {
847     bool isCustom = false;
848     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
849                                  SrcVT.getSimpleVT())) {
850     default: llvm_unreachable("This action is not supported yet!");
851     case TargetLowering::Custom:
852       isCustom = true;
853       LLVM_FALLTHROUGH;
854     case TargetLowering::Legal:
855       Value = SDValue(Node, 0);
856       Chain = SDValue(Node, 1);
857 
858       if (isCustom) {
859         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
860           Value = Res;
861           Chain = Res.getValue(1);
862         }
863       } else {
864         // If this is an unaligned load and the target doesn't support it,
865         // expand it.
866         EVT MemVT = LD->getMemoryVT();
867         const DataLayout &DL = DAG.getDataLayout();
868         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT,
869                                     *LD->getMemOperand())) {
870           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
871         }
872       }
873       break;
874 
875     case TargetLowering::Expand: {
876       EVT DestVT = Node->getValueType(0);
877       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
878         // If the source type is not legal, see if there is a legal extload to
879         // an intermediate type that we can then extend further.
880         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
881         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
882             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
883           // If we are loading a legal type, this is a non-extload followed by a
884           // full extend.
885           ISD::LoadExtType MidExtType =
886               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
887 
888           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
889                                         SrcVT, LD->getMemOperand());
890           unsigned ExtendOp =
891               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
892           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
893           Chain = Load.getValue(1);
894           break;
895         }
896 
897         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
898         // normal undefined upper bits behavior to allow using an in-reg extend
899         // with the illegal FP type, so load as an integer and do the
900         // from-integer conversion.
901         if (SrcVT.getScalarType() == MVT::f16) {
902           EVT ISrcVT = SrcVT.changeTypeToInteger();
903           EVT IDestVT = DestVT.changeTypeToInteger();
904           EVT ILoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
905 
906           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, ILoadVT, Chain,
907                                           Ptr, ISrcVT, LD->getMemOperand());
908           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
909           Chain = Result.getValue(1);
910           break;
911         }
912       }
913 
914       assert(!SrcVT.isVector() &&
915              "Vector Loads are handled in LegalizeVectorOps");
916 
917       // FIXME: This does not work for vectors on most targets.  Sign-
918       // and zero-extend operations are currently folded into extending
919       // loads, whether they are legal or not, and then we end up here
920       // without any support for legalizing them.
921       assert(ExtType != ISD::EXTLOAD &&
922              "EXTLOAD should always be supported!");
923       // Turn the unsupported load into an EXTLOAD followed by an
924       // explicit zero/sign extend inreg.
925       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
926                                       Node->getValueType(0),
927                                       Chain, Ptr, SrcVT,
928                                       LD->getMemOperand());
929       SDValue ValRes;
930       if (ExtType == ISD::SEXTLOAD)
931         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
932                              Result.getValueType(),
933                              Result, DAG.getValueType(SrcVT));
934       else
935         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT);
936       Value = ValRes;
937       Chain = Result.getValue(1);
938       break;
939     }
940     }
941   }
942 
943   // Since loads produce two values, make sure to remember that we legalized
944   // both of them.
945   if (Chain.getNode() != Node) {
946     assert(Value.getNode() != Node && "Load must be completely replaced");
947     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
948     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
949     if (UpdatedNodes) {
950       UpdatedNodes->insert(Value.getNode());
951       UpdatedNodes->insert(Chain.getNode());
952     }
953     ReplacedNode(Node);
954   }
955 }
956 
957 /// Return a legal replacement for the given operation, with all legal operands.
958 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
959   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
960 
961   // Allow illegal target nodes and illegal registers.
962   if (Node->getOpcode() == ISD::TargetConstant ||
963       Node->getOpcode() == ISD::Register)
964     return;
965 
966 #ifndef NDEBUG
967   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
968     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
969              TargetLowering::TypeLegal &&
970            "Unexpected illegal type!");
971 
972   for (const SDValue &Op : Node->op_values())
973     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
974               TargetLowering::TypeLegal ||
975             Op.getOpcode() == ISD::TargetConstant ||
976             Op.getOpcode() == ISD::Register) &&
977             "Unexpected illegal type!");
978 #endif
979 
980   // Figure out the correct action; the way to query this varies by opcode
981   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
982   bool SimpleFinishLegalizing = true;
983   switch (Node->getOpcode()) {
984   case ISD::INTRINSIC_W_CHAIN:
985   case ISD::INTRINSIC_WO_CHAIN:
986   case ISD::INTRINSIC_VOID:
987   case ISD::STACKSAVE:
988     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
989     break;
990   case ISD::GET_DYNAMIC_AREA_OFFSET:
991     Action = TLI.getOperationAction(Node->getOpcode(),
992                                     Node->getValueType(0));
993     break;
994   case ISD::VAARG:
995     Action = TLI.getOperationAction(Node->getOpcode(),
996                                     Node->getValueType(0));
997     if (Action != TargetLowering::Promote)
998       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
999     break;
1000   case ISD::FP_TO_FP16:
1001   case ISD::FP_TO_BF16:
1002   case ISD::SINT_TO_FP:
1003   case ISD::UINT_TO_FP:
1004   case ISD::EXTRACT_VECTOR_ELT:
1005   case ISD::LROUND:
1006   case ISD::LLROUND:
1007   case ISD::LRINT:
1008   case ISD::LLRINT:
1009     Action = TLI.getOperationAction(Node->getOpcode(),
1010                                     Node->getOperand(0).getValueType());
1011     break;
1012   case ISD::STRICT_FP_TO_FP16:
1013   case ISD::STRICT_SINT_TO_FP:
1014   case ISD::STRICT_UINT_TO_FP:
1015   case ISD::STRICT_LRINT:
1016   case ISD::STRICT_LLRINT:
1017   case ISD::STRICT_LROUND:
1018   case ISD::STRICT_LLROUND:
1019     // These pseudo-ops are the same as the other STRICT_ ops except
1020     // they are registered with setOperationAction() using the input type
1021     // instead of the output type.
1022     Action = TLI.getOperationAction(Node->getOpcode(),
1023                                     Node->getOperand(1).getValueType());
1024     break;
1025   case ISD::SIGN_EXTEND_INREG: {
1026     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1027     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1028     break;
1029   }
1030   case ISD::ATOMIC_STORE:
1031     Action = TLI.getOperationAction(Node->getOpcode(),
1032                                     Node->getOperand(2).getValueType());
1033     break;
1034   case ISD::SELECT_CC:
1035   case ISD::STRICT_FSETCC:
1036   case ISD::STRICT_FSETCCS:
1037   case ISD::SETCC:
1038   case ISD::VP_SETCC:
1039   case ISD::BR_CC: {
1040     unsigned Opc = Node->getOpcode();
1041     unsigned CCOperand = Opc == ISD::SELECT_CC                         ? 4
1042                          : Opc == ISD::STRICT_FSETCC                   ? 3
1043                          : Opc == ISD::STRICT_FSETCCS                  ? 3
1044                          : (Opc == ISD::SETCC || Opc == ISD::VP_SETCC) ? 2
1045                                                                        : 1;
1046     unsigned CompareOperand = Opc == ISD::BR_CC            ? 2
1047                               : Opc == ISD::STRICT_FSETCC  ? 1
1048                               : Opc == ISD::STRICT_FSETCCS ? 1
1049                                                            : 0;
1050     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1051     ISD::CondCode CCCode =
1052         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1053     Action = TLI.getCondCodeAction(CCCode, OpVT);
1054     if (Action == TargetLowering::Legal) {
1055       if (Node->getOpcode() == ISD::SELECT_CC)
1056         Action = TLI.getOperationAction(Node->getOpcode(),
1057                                         Node->getValueType(0));
1058       else
1059         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1060     }
1061     break;
1062   }
1063   case ISD::LOAD:
1064   case ISD::STORE:
1065     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1066     // STORE expects the unlegalized operand in some cases.
1067     SimpleFinishLegalizing = false;
1068     break;
1069   case ISD::CALLSEQ_START:
1070   case ISD::CALLSEQ_END:
1071     // FIXME: This shouldn't be necessary.  These nodes have special properties
1072     // dealing with the recursive nature of legalization.  Removing this
1073     // special case should be done as part of making LegalizeDAG non-recursive.
1074     SimpleFinishLegalizing = false;
1075     break;
1076   case ISD::EXTRACT_ELEMENT:
1077   case ISD::FLT_ROUNDS_:
1078   case ISD::MERGE_VALUES:
1079   case ISD::EH_RETURN:
1080   case ISD::FRAME_TO_ARGS_OFFSET:
1081   case ISD::EH_DWARF_CFA:
1082   case ISD::EH_SJLJ_SETJMP:
1083   case ISD::EH_SJLJ_LONGJMP:
1084   case ISD::EH_SJLJ_SETUP_DISPATCH:
1085     // These operations lie about being legal: when they claim to be legal,
1086     // they should actually be expanded.
1087     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1088     if (Action == TargetLowering::Legal)
1089       Action = TargetLowering::Expand;
1090     break;
1091   case ISD::INIT_TRAMPOLINE:
1092   case ISD::ADJUST_TRAMPOLINE:
1093   case ISD::FRAMEADDR:
1094   case ISD::RETURNADDR:
1095   case ISD::ADDROFRETURNADDR:
1096   case ISD::SPONENTRY:
1097     // These operations lie about being legal: when they claim to be legal,
1098     // they should actually be custom-lowered.
1099     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1100     if (Action == TargetLowering::Legal)
1101       Action = TargetLowering::Custom;
1102     break;
1103   case ISD::READCYCLECOUNTER:
1104     // READCYCLECOUNTER returns an i64, even if type legalization might have
1105     // expanded that to several smaller types.
1106     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1107     break;
1108   case ISD::READ_REGISTER:
1109   case ISD::WRITE_REGISTER:
1110     // Named register is legal in the DAG, but blocked by register name
1111     // selection if not implemented by target (to chose the correct register)
1112     // They'll be converted to Copy(To/From)Reg.
1113     Action = TargetLowering::Legal;
1114     break;
1115   case ISD::UBSANTRAP:
1116     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1117     if (Action == TargetLowering::Expand) {
1118       // replace ISD::UBSANTRAP with ISD::TRAP
1119       SDValue NewVal;
1120       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1121                            Node->getOperand(0));
1122       ReplaceNode(Node, NewVal.getNode());
1123       LegalizeOp(NewVal.getNode());
1124       return;
1125     }
1126     break;
1127   case ISD::DEBUGTRAP:
1128     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1129     if (Action == TargetLowering::Expand) {
1130       // replace ISD::DEBUGTRAP with ISD::TRAP
1131       SDValue NewVal;
1132       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1133                            Node->getOperand(0));
1134       ReplaceNode(Node, NewVal.getNode());
1135       LegalizeOp(NewVal.getNode());
1136       return;
1137     }
1138     break;
1139   case ISD::SADDSAT:
1140   case ISD::UADDSAT:
1141   case ISD::SSUBSAT:
1142   case ISD::USUBSAT:
1143   case ISD::SSHLSAT:
1144   case ISD::USHLSAT:
1145   case ISD::FP_TO_SINT_SAT:
1146   case ISD::FP_TO_UINT_SAT:
1147     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1148     break;
1149   case ISD::SMULFIX:
1150   case ISD::SMULFIXSAT:
1151   case ISD::UMULFIX:
1152   case ISD::UMULFIXSAT:
1153   case ISD::SDIVFIX:
1154   case ISD::SDIVFIXSAT:
1155   case ISD::UDIVFIX:
1156   case ISD::UDIVFIXSAT: {
1157     unsigned Scale = Node->getConstantOperandVal(2);
1158     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1159                                               Node->getValueType(0), Scale);
1160     break;
1161   }
1162   case ISD::MSCATTER:
1163     Action = TLI.getOperationAction(Node->getOpcode(),
1164                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1165     break;
1166   case ISD::MSTORE:
1167     Action = TLI.getOperationAction(Node->getOpcode(),
1168                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1169     break;
1170   case ISD::VP_SCATTER:
1171     Action = TLI.getOperationAction(
1172         Node->getOpcode(),
1173         cast<VPScatterSDNode>(Node)->getValue().getValueType());
1174     break;
1175   case ISD::VP_STORE:
1176     Action = TLI.getOperationAction(
1177         Node->getOpcode(),
1178         cast<VPStoreSDNode>(Node)->getValue().getValueType());
1179     break;
1180   case ISD::EXPERIMENTAL_VP_STRIDED_STORE:
1181     Action = TLI.getOperationAction(
1182         Node->getOpcode(),
1183         cast<VPStridedStoreSDNode>(Node)->getValue().getValueType());
1184     break;
1185   case ISD::VECREDUCE_FADD:
1186   case ISD::VECREDUCE_FMUL:
1187   case ISD::VECREDUCE_ADD:
1188   case ISD::VECREDUCE_MUL:
1189   case ISD::VECREDUCE_AND:
1190   case ISD::VECREDUCE_OR:
1191   case ISD::VECREDUCE_XOR:
1192   case ISD::VECREDUCE_SMAX:
1193   case ISD::VECREDUCE_SMIN:
1194   case ISD::VECREDUCE_UMAX:
1195   case ISD::VECREDUCE_UMIN:
1196   case ISD::VECREDUCE_FMAX:
1197   case ISD::VECREDUCE_FMIN:
1198   case ISD::IS_FPCLASS:
1199     Action = TLI.getOperationAction(
1200         Node->getOpcode(), Node->getOperand(0).getValueType());
1201     break;
1202   case ISD::VECREDUCE_SEQ_FADD:
1203   case ISD::VECREDUCE_SEQ_FMUL:
1204   case ISD::VP_REDUCE_FADD:
1205   case ISD::VP_REDUCE_FMUL:
1206   case ISD::VP_REDUCE_ADD:
1207   case ISD::VP_REDUCE_MUL:
1208   case ISD::VP_REDUCE_AND:
1209   case ISD::VP_REDUCE_OR:
1210   case ISD::VP_REDUCE_XOR:
1211   case ISD::VP_REDUCE_SMAX:
1212   case ISD::VP_REDUCE_SMIN:
1213   case ISD::VP_REDUCE_UMAX:
1214   case ISD::VP_REDUCE_UMIN:
1215   case ISD::VP_REDUCE_FMAX:
1216   case ISD::VP_REDUCE_FMIN:
1217   case ISD::VP_REDUCE_SEQ_FADD:
1218   case ISD::VP_REDUCE_SEQ_FMUL:
1219     Action = TLI.getOperationAction(
1220         Node->getOpcode(), Node->getOperand(1).getValueType());
1221     break;
1222   default:
1223     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1224       Action = TLI.getCustomOperationAction(*Node);
1225     } else {
1226       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1227     }
1228     break;
1229   }
1230 
1231   if (SimpleFinishLegalizing) {
1232     SDNode *NewNode = Node;
1233     switch (Node->getOpcode()) {
1234     default: break;
1235     case ISD::SHL:
1236     case ISD::SRL:
1237     case ISD::SRA:
1238     case ISD::ROTL:
1239     case ISD::ROTR: {
1240       // Legalizing shifts/rotates requires adjusting the shift amount
1241       // to the appropriate width.
1242       SDValue Op0 = Node->getOperand(0);
1243       SDValue Op1 = Node->getOperand(1);
1244       if (!Op1.getValueType().isVector()) {
1245         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1246         // The getShiftAmountOperand() may create a new operand node or
1247         // return the existing one. If new operand is created we need
1248         // to update the parent node.
1249         // Do not try to legalize SAO here! It will be automatically legalized
1250         // in the next round.
1251         if (SAO != Op1)
1252           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1253       }
1254     }
1255     break;
1256     case ISD::FSHL:
1257     case ISD::FSHR:
1258     case ISD::SRL_PARTS:
1259     case ISD::SRA_PARTS:
1260     case ISD::SHL_PARTS: {
1261       // Legalizing shifts/rotates requires adjusting the shift amount
1262       // to the appropriate width.
1263       SDValue Op0 = Node->getOperand(0);
1264       SDValue Op1 = Node->getOperand(1);
1265       SDValue Op2 = Node->getOperand(2);
1266       if (!Op2.getValueType().isVector()) {
1267         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1268         // The getShiftAmountOperand() may create a new operand node or
1269         // return the existing one. If new operand is created we need
1270         // to update the parent node.
1271         if (SAO != Op2)
1272           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1273       }
1274       break;
1275     }
1276     }
1277 
1278     if (NewNode != Node) {
1279       ReplaceNode(Node, NewNode);
1280       Node = NewNode;
1281     }
1282     switch (Action) {
1283     case TargetLowering::Legal:
1284       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1285       return;
1286     case TargetLowering::Custom:
1287       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1288       // FIXME: The handling for custom lowering with multiple results is
1289       // a complete mess.
1290       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1291         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1292           return;
1293 
1294         if (Node->getNumValues() == 1) {
1295           // Verify the new types match the original. Glue is waived because
1296           // ISD::ADDC can be legalized by replacing Glue with an integer type.
1297           assert((Res.getValueType() == Node->getValueType(0) ||
1298                   Node->getValueType(0) == MVT::Glue) &&
1299                  "Type mismatch for custom legalized operation");
1300           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1301           // We can just directly replace this node with the lowered value.
1302           ReplaceNode(SDValue(Node, 0), Res);
1303           return;
1304         }
1305 
1306         SmallVector<SDValue, 8> ResultVals;
1307         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) {
1308           // Verify the new types match the original. Glue is waived because
1309           // ISD::ADDC can be legalized by replacing Glue with an integer type.
1310           assert((Res->getValueType(i) == Node->getValueType(i) ||
1311                   Node->getValueType(i) == MVT::Glue) &&
1312                  "Type mismatch for custom legalized operation");
1313           ResultVals.push_back(Res.getValue(i));
1314         }
1315         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1316         ReplaceNode(Node, ResultVals.data());
1317         return;
1318       }
1319       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1320       LLVM_FALLTHROUGH;
1321     case TargetLowering::Expand:
1322       if (ExpandNode(Node))
1323         return;
1324       LLVM_FALLTHROUGH;
1325     case TargetLowering::LibCall:
1326       ConvertNodeToLibcall(Node);
1327       return;
1328     case TargetLowering::Promote:
1329       PromoteNode(Node);
1330       return;
1331     }
1332   }
1333 
1334   switch (Node->getOpcode()) {
1335   default:
1336 #ifndef NDEBUG
1337     dbgs() << "NODE: ";
1338     Node->dump( &DAG);
1339     dbgs() << "\n";
1340 #endif
1341     llvm_unreachable("Do not know how to legalize this operator!");
1342 
1343   case ISD::CALLSEQ_START:
1344   case ISD::CALLSEQ_END:
1345     break;
1346   case ISD::LOAD:
1347     return LegalizeLoadOps(Node);
1348   case ISD::STORE:
1349     return LegalizeStoreOps(Node);
1350   }
1351 }
1352 
1353 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1354   SDValue Vec = Op.getOperand(0);
1355   SDValue Idx = Op.getOperand(1);
1356   SDLoc dl(Op);
1357 
1358   // Before we generate a new store to a temporary stack slot, see if there is
1359   // already one that we can use. There often is because when we scalarize
1360   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1361   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1362   // the vector. If all are expanded here, we don't want one store per vector
1363   // element.
1364 
1365   // Caches for hasPredecessorHelper
1366   SmallPtrSet<const SDNode *, 32> Visited;
1367   SmallVector<const SDNode *, 16> Worklist;
1368   Visited.insert(Op.getNode());
1369   Worklist.push_back(Idx.getNode());
1370   SDValue StackPtr, Ch;
1371   for (SDNode *User : Vec.getNode()->uses()) {
1372     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1373       if (ST->isIndexed() || ST->isTruncatingStore() ||
1374           ST->getValue() != Vec)
1375         continue;
1376 
1377       // Make sure that nothing else could have stored into the destination of
1378       // this store.
1379       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1380         continue;
1381 
1382       // If the index is dependent on the store we will introduce a cycle when
1383       // creating the load (the load uses the index, and by replacing the chain
1384       // we will make the index dependent on the load). Also, the store might be
1385       // dependent on the extractelement and introduce a cycle when creating
1386       // the load.
1387       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1388           ST->hasPredecessor(Op.getNode()))
1389         continue;
1390 
1391       StackPtr = ST->getBasePtr();
1392       Ch = SDValue(ST, 0);
1393       break;
1394     }
1395   }
1396 
1397   EVT VecVT = Vec.getValueType();
1398 
1399   if (!Ch.getNode()) {
1400     // Store the value to a temporary stack slot, then LOAD the returned part.
1401     StackPtr = DAG.CreateStackTemporary(VecVT);
1402     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1403                       MachinePointerInfo());
1404   }
1405 
1406   SDValue NewLoad;
1407   Align ElementAlignment =
1408       std::min(cast<StoreSDNode>(Ch)->getAlign(),
1409                DAG.getDataLayout().getPrefTypeAlign(
1410                    Op.getValueType().getTypeForEVT(*DAG.getContext())));
1411 
1412   if (Op.getValueType().isVector()) {
1413     StackPtr = TLI.getVectorSubVecPointer(DAG, StackPtr, VecVT,
1414                                           Op.getValueType(), Idx);
1415     NewLoad = DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr,
1416                           MachinePointerInfo(), ElementAlignment);
1417   } else {
1418     StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1419     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1420                              MachinePointerInfo(), VecVT.getVectorElementType(),
1421                              ElementAlignment);
1422   }
1423 
1424   // Replace the chain going out of the store, by the one out of the load.
1425   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1426 
1427   // We introduced a cycle though, so update the loads operands, making sure
1428   // to use the original store's chain as an incoming chain.
1429   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1430                                           NewLoad->op_end());
1431   NewLoadOperands[0] = Ch;
1432   NewLoad =
1433       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1434   return NewLoad;
1435 }
1436 
1437 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1438   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1439 
1440   SDValue Vec  = Op.getOperand(0);
1441   SDValue Part = Op.getOperand(1);
1442   SDValue Idx  = Op.getOperand(2);
1443   SDLoc dl(Op);
1444 
1445   // Store the value to a temporary stack slot, then LOAD the returned part.
1446   EVT VecVT = Vec.getValueType();
1447   EVT SubVecVT = Part.getValueType();
1448   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1449   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1450   MachinePointerInfo PtrInfo =
1451       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1452 
1453   // First store the whole vector.
1454   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1455 
1456   // Then store the inserted part.
1457   SDValue SubStackPtr =
1458       TLI.getVectorSubVecPointer(DAG, StackPtr, VecVT, SubVecVT, Idx);
1459 
1460   // Store the subvector.
1461   Ch = DAG.getStore(
1462       Ch, dl, Part, SubStackPtr,
1463       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()));
1464 
1465   // Finally, load the updated vector.
1466   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1467 }
1468 
1469 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1470   assert((Node->getOpcode() == ISD::BUILD_VECTOR ||
1471           Node->getOpcode() == ISD::CONCAT_VECTORS) &&
1472          "Unexpected opcode!");
1473 
1474   // We can't handle this case efficiently.  Allocate a sufficiently
1475   // aligned object on the stack, store each operand into it, then load
1476   // the result as a vector.
1477   // Create the stack frame object.
1478   EVT VT = Node->getValueType(0);
1479   EVT MemVT = isa<BuildVectorSDNode>(Node) ? VT.getVectorElementType()
1480                                            : Node->getOperand(0).getValueType();
1481   SDLoc dl(Node);
1482   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1483   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1484   MachinePointerInfo PtrInfo =
1485       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1486 
1487   // Emit a store of each element to the stack slot.
1488   SmallVector<SDValue, 8> Stores;
1489   unsigned TypeByteSize = MemVT.getSizeInBits() / 8;
1490   assert(TypeByteSize > 0 && "Vector element type too small for stack store!");
1491 
1492   // If the destination vector element type of a BUILD_VECTOR is narrower than
1493   // the source element type, only store the bits necessary.
1494   bool Truncate = isa<BuildVectorSDNode>(Node) &&
1495                   MemVT.bitsLT(Node->getOperand(0).getValueType());
1496 
1497   // Store (in the right endianness) the elements to memory.
1498   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1499     // Ignore undef elements.
1500     if (Node->getOperand(i).isUndef()) continue;
1501 
1502     unsigned Offset = TypeByteSize*i;
1503 
1504     SDValue Idx = DAG.getMemBasePlusOffset(FIPtr, TypeSize::Fixed(Offset), dl);
1505 
1506     if (Truncate)
1507       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1508                                          Node->getOperand(i), Idx,
1509                                          PtrInfo.getWithOffset(Offset), MemVT));
1510     else
1511       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1512                                     Idx, PtrInfo.getWithOffset(Offset)));
1513   }
1514 
1515   SDValue StoreChain;
1516   if (!Stores.empty())    // Not all undef elements?
1517     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1518   else
1519     StoreChain = DAG.getEntryNode();
1520 
1521   // Result is a load from the stack slot.
1522   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1523 }
1524 
1525 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1526 /// containing the sign bit if the target has no integer value capable of
1527 /// holding all bits of the floating-point value.
1528 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1529                                              const SDLoc &DL,
1530                                              SDValue Value) const {
1531   EVT FloatVT = Value.getValueType();
1532   unsigned NumBits = FloatVT.getScalarSizeInBits();
1533   State.FloatVT = FloatVT;
1534   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1535   // Convert to an integer of the same size.
1536   if (TLI.isTypeLegal(IVT)) {
1537     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1538     State.SignMask = APInt::getSignMask(NumBits);
1539     State.SignBit = NumBits - 1;
1540     return;
1541   }
1542 
1543   auto &DataLayout = DAG.getDataLayout();
1544   // Store the float to memory, then load the sign part out as an integer.
1545   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1546   // First create a temporary that is aligned for both the load and store.
1547   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1548   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1549   // Then store the float to it.
1550   State.FloatPtr = StackPtr;
1551   MachineFunction &MF = DAG.getMachineFunction();
1552   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1553   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1554                              State.FloatPointerInfo);
1555 
1556   SDValue IntPtr;
1557   if (DataLayout.isBigEndian()) {
1558     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1559     // Load out a legal integer with the same sign bit as the float.
1560     IntPtr = StackPtr;
1561     State.IntPointerInfo = State.FloatPointerInfo;
1562   } else {
1563     // Advance the pointer so that the loaded byte will contain the sign bit.
1564     unsigned ByteOffset = (NumBits / 8) - 1;
1565     IntPtr =
1566         DAG.getMemBasePlusOffset(StackPtr, TypeSize::Fixed(ByteOffset), DL);
1567     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1568                                                              ByteOffset);
1569   }
1570 
1571   State.IntPtr = IntPtr;
1572   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1573                                   State.IntPointerInfo, MVT::i8);
1574   State.SignMask = APInt::getOneBitSet(LoadTy.getScalarSizeInBits(), 7);
1575   State.SignBit = 7;
1576 }
1577 
1578 /// Replace the integer value produced by getSignAsIntValue() with a new value
1579 /// and cast the result back to a floating-point type.
1580 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1581                                               const SDLoc &DL,
1582                                               SDValue NewIntValue) const {
1583   if (!State.Chain)
1584     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1585 
1586   // Override the part containing the sign bit in the value stored on the stack.
1587   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1588                                     State.IntPointerInfo, MVT::i8);
1589   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1590                      State.FloatPointerInfo);
1591 }
1592 
1593 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1594   SDLoc DL(Node);
1595   SDValue Mag = Node->getOperand(0);
1596   SDValue Sign = Node->getOperand(1);
1597 
1598   // Get sign bit into an integer value.
1599   FloatSignAsInt SignAsInt;
1600   getSignAsIntValue(SignAsInt, DL, Sign);
1601 
1602   EVT IntVT = SignAsInt.IntValue.getValueType();
1603   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1604   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1605                                 SignMask);
1606 
1607   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1608   EVT FloatVT = Mag.getValueType();
1609   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1610       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1611     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1612     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1613     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1614                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1615     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1616   }
1617 
1618   // Transform Mag value to integer, and clear the sign bit.
1619   FloatSignAsInt MagAsInt;
1620   getSignAsIntValue(MagAsInt, DL, Mag);
1621   EVT MagVT = MagAsInt.IntValue.getValueType();
1622   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1623   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1624                                     ClearSignMask);
1625 
1626   // Get the signbit at the right position for MagAsInt.
1627   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1628   EVT ShiftVT = IntVT;
1629   if (SignBit.getScalarValueSizeInBits() <
1630       ClearedSign.getScalarValueSizeInBits()) {
1631     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1632     ShiftVT = MagVT;
1633   }
1634   if (ShiftAmount > 0) {
1635     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1636     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1637   } else if (ShiftAmount < 0) {
1638     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1639     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1640   }
1641   if (SignBit.getScalarValueSizeInBits() >
1642       ClearedSign.getScalarValueSizeInBits()) {
1643     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1644   }
1645 
1646   // Store the part with the modified sign and convert back to float.
1647   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1648   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1649 }
1650 
1651 SDValue SelectionDAGLegalize::ExpandFNEG(SDNode *Node) const {
1652   // Get the sign bit as an integer.
1653   SDLoc DL(Node);
1654   FloatSignAsInt SignAsInt;
1655   getSignAsIntValue(SignAsInt, DL, Node->getOperand(0));
1656   EVT IntVT = SignAsInt.IntValue.getValueType();
1657 
1658   // Flip the sign.
1659   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1660   SDValue SignFlip =
1661       DAG.getNode(ISD::XOR, DL, IntVT, SignAsInt.IntValue, SignMask);
1662 
1663   // Convert back to float.
1664   return modifySignAsInt(SignAsInt, DL, SignFlip);
1665 }
1666 
1667 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1668   SDLoc DL(Node);
1669   SDValue Value = Node->getOperand(0);
1670 
1671   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1672   EVT FloatVT = Value.getValueType();
1673   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1674     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1675     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1676   }
1677 
1678   // Transform value to integer, clear the sign bit and transform back.
1679   FloatSignAsInt ValueAsInt;
1680   getSignAsIntValue(ValueAsInt, DL, Value);
1681   EVT IntVT = ValueAsInt.IntValue.getValueType();
1682   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1683   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1684                                     ClearSignMask);
1685   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1686 }
1687 
1688 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1689                                            SmallVectorImpl<SDValue> &Results) {
1690   Register SPReg = TLI.getStackPointerRegisterToSaveRestore();
1691   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1692           " not tell us which reg is the stack pointer!");
1693   SDLoc dl(Node);
1694   EVT VT = Node->getValueType(0);
1695   SDValue Tmp1 = SDValue(Node, 0);
1696   SDValue Tmp2 = SDValue(Node, 1);
1697   SDValue Tmp3 = Node->getOperand(2);
1698   SDValue Chain = Tmp1.getOperand(0);
1699 
1700   // Chain the dynamic stack allocation so that it doesn't modify the stack
1701   // pointer when other instructions are using the stack.
1702   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1703 
1704   SDValue Size  = Tmp2.getOperand(1);
1705   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1706   Chain = SP.getValue(1);
1707   Align Alignment = cast<ConstantSDNode>(Tmp3)->getAlignValue();
1708   const TargetFrameLowering *TFL = DAG.getSubtarget().getFrameLowering();
1709   unsigned Opc =
1710     TFL->getStackGrowthDirection() == TargetFrameLowering::StackGrowsUp ?
1711     ISD::ADD : ISD::SUB;
1712 
1713   Align StackAlign = TFL->getStackAlign();
1714   Tmp1 = DAG.getNode(Opc, dl, VT, SP, Size);       // Value
1715   if (Alignment > StackAlign)
1716     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1717                        DAG.getConstant(-Alignment.value(), dl, VT));
1718   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1719 
1720   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1721                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1722 
1723   Results.push_back(Tmp1);
1724   Results.push_back(Tmp2);
1725 }
1726 
1727 /// Emit a store/load combination to the stack.  This stores
1728 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1729 /// a load from the stack slot to DestVT, extending it if needed.
1730 /// The resultant code need not be legal.
1731 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1732                                                EVT DestVT, const SDLoc &dl) {
1733   return EmitStackConvert(SrcOp, SlotVT, DestVT, dl, DAG.getEntryNode());
1734 }
1735 
1736 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1737                                                EVT DestVT, const SDLoc &dl,
1738                                                SDValue Chain) {
1739   EVT SrcVT = SrcOp.getValueType();
1740   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1741   Align DestAlign = DAG.getDataLayout().getPrefTypeAlign(DestType);
1742 
1743   // Don't convert with stack if the load/store is expensive.
1744   if ((SrcVT.bitsGT(SlotVT) &&
1745        !TLI.isTruncStoreLegalOrCustom(SrcOp.getValueType(), SlotVT)) ||
1746       (SlotVT.bitsLT(DestVT) &&
1747        !TLI.isLoadExtLegalOrCustom(ISD::EXTLOAD, DestVT, SlotVT)))
1748     return SDValue();
1749 
1750   // Create the stack frame object.
1751   Align SrcAlign = DAG.getDataLayout().getPrefTypeAlign(
1752       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1753   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT.getStoreSize(), SrcAlign);
1754 
1755   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1756   int SPFI = StackPtrFI->getIndex();
1757   MachinePointerInfo PtrInfo =
1758       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1759 
1760   // Emit a store to the stack slot.  Use a truncstore if the input value is
1761   // later than DestVT.
1762   SDValue Store;
1763 
1764   if (SrcVT.bitsGT(SlotVT))
1765     Store = DAG.getTruncStore(Chain, dl, SrcOp, FIPtr, PtrInfo,
1766                               SlotVT, SrcAlign);
1767   else {
1768     assert(SrcVT.bitsEq(SlotVT) && "Invalid store");
1769     Store = DAG.getStore(Chain, dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1770   }
1771 
1772   // Result is a load from the stack slot.
1773   if (SlotVT.bitsEq(DestVT))
1774     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1775 
1776   assert(SlotVT.bitsLT(DestVT) && "Unknown extension!");
1777   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1778                         DestAlign);
1779 }
1780 
1781 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1782   SDLoc dl(Node);
1783   // Create a vector sized/aligned stack slot, store the value to element #0,
1784   // then load the whole vector back out.
1785   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1786 
1787   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1788   int SPFI = StackPtrFI->getIndex();
1789 
1790   SDValue Ch = DAG.getTruncStore(
1791       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1792       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1793       Node->getValueType(0).getVectorElementType());
1794   return DAG.getLoad(
1795       Node->getValueType(0), dl, Ch, StackPtr,
1796       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1797 }
1798 
1799 static bool
1800 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1801                      const TargetLowering &TLI, SDValue &Res) {
1802   unsigned NumElems = Node->getNumOperands();
1803   SDLoc dl(Node);
1804   EVT VT = Node->getValueType(0);
1805 
1806   // Try to group the scalars into pairs, shuffle the pairs together, then
1807   // shuffle the pairs of pairs together, etc. until the vector has
1808   // been built. This will work only if all of the necessary shuffle masks
1809   // are legal.
1810 
1811   // We do this in two phases; first to check the legality of the shuffles,
1812   // and next, assuming that all shuffles are legal, to create the new nodes.
1813   for (int Phase = 0; Phase < 2; ++Phase) {
1814     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1815                                                               NewIntermedVals;
1816     for (unsigned i = 0; i < NumElems; ++i) {
1817       SDValue V = Node->getOperand(i);
1818       if (V.isUndef())
1819         continue;
1820 
1821       SDValue Vec;
1822       if (Phase)
1823         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1824       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1825     }
1826 
1827     while (IntermedVals.size() > 2) {
1828       NewIntermedVals.clear();
1829       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1830         // This vector and the next vector are shuffled together (simply to
1831         // append the one to the other).
1832         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1833 
1834         SmallVector<int, 16> FinalIndices;
1835         FinalIndices.reserve(IntermedVals[i].second.size() +
1836                              IntermedVals[i+1].second.size());
1837 
1838         int k = 0;
1839         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1840              ++j, ++k) {
1841           ShuffleVec[k] = j;
1842           FinalIndices.push_back(IntermedVals[i].second[j]);
1843         }
1844         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1845              ++j, ++k) {
1846           ShuffleVec[k] = NumElems + j;
1847           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1848         }
1849 
1850         SDValue Shuffle;
1851         if (Phase)
1852           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1853                                          IntermedVals[i+1].first,
1854                                          ShuffleVec);
1855         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1856           return false;
1857         NewIntermedVals.push_back(
1858             std::make_pair(Shuffle, std::move(FinalIndices)));
1859       }
1860 
1861       // If we had an odd number of defined values, then append the last
1862       // element to the array of new vectors.
1863       if ((IntermedVals.size() & 1) != 0)
1864         NewIntermedVals.push_back(IntermedVals.back());
1865 
1866       IntermedVals.swap(NewIntermedVals);
1867     }
1868 
1869     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1870            "Invalid number of intermediate vectors");
1871     SDValue Vec1 = IntermedVals[0].first;
1872     SDValue Vec2;
1873     if (IntermedVals.size() > 1)
1874       Vec2 = IntermedVals[1].first;
1875     else if (Phase)
1876       Vec2 = DAG.getUNDEF(VT);
1877 
1878     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1879     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1880       ShuffleVec[IntermedVals[0].second[i]] = i;
1881     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1882       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1883 
1884     if (Phase)
1885       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1886     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1887       return false;
1888   }
1889 
1890   return true;
1891 }
1892 
1893 /// Expand a BUILD_VECTOR node on targets that don't
1894 /// support the operation, but do support the resultant vector type.
1895 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1896   unsigned NumElems = Node->getNumOperands();
1897   SDValue Value1, Value2;
1898   SDLoc dl(Node);
1899   EVT VT = Node->getValueType(0);
1900   EVT OpVT = Node->getOperand(0).getValueType();
1901   EVT EltVT = VT.getVectorElementType();
1902 
1903   // If the only non-undef value is the low element, turn this into a
1904   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1905   bool isOnlyLowElement = true;
1906   bool MoreThanTwoValues = false;
1907   bool isConstant = true;
1908   for (unsigned i = 0; i < NumElems; ++i) {
1909     SDValue V = Node->getOperand(i);
1910     if (V.isUndef())
1911       continue;
1912     if (i > 0)
1913       isOnlyLowElement = false;
1914     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1915       isConstant = false;
1916 
1917     if (!Value1.getNode()) {
1918       Value1 = V;
1919     } else if (!Value2.getNode()) {
1920       if (V != Value1)
1921         Value2 = V;
1922     } else if (V != Value1 && V != Value2) {
1923       MoreThanTwoValues = true;
1924     }
1925   }
1926 
1927   if (!Value1.getNode())
1928     return DAG.getUNDEF(VT);
1929 
1930   if (isOnlyLowElement)
1931     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1932 
1933   // If all elements are constants, create a load from the constant pool.
1934   if (isConstant) {
1935     SmallVector<Constant*, 16> CV;
1936     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1937       if (ConstantFPSDNode *V =
1938           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1939         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1940       } else if (ConstantSDNode *V =
1941                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1942         if (OpVT==EltVT)
1943           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1944         else {
1945           // If OpVT and EltVT don't match, EltVT is not legal and the
1946           // element values have been promoted/truncated earlier.  Undo this;
1947           // we don't want a v16i8 to become a v16i32 for example.
1948           const ConstantInt *CI = V->getConstantIntValue();
1949           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1950                                         CI->getZExtValue()));
1951         }
1952       } else {
1953         assert(Node->getOperand(i).isUndef());
1954         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1955         CV.push_back(UndefValue::get(OpNTy));
1956       }
1957     }
1958     Constant *CP = ConstantVector::get(CV);
1959     SDValue CPIdx =
1960         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1961     Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
1962     return DAG.getLoad(
1963         VT, dl, DAG.getEntryNode(), CPIdx,
1964         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1965         Alignment);
1966   }
1967 
1968   SmallSet<SDValue, 16> DefinedValues;
1969   for (unsigned i = 0; i < NumElems; ++i) {
1970     if (Node->getOperand(i).isUndef())
1971       continue;
1972     DefinedValues.insert(Node->getOperand(i));
1973   }
1974 
1975   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1976     if (!MoreThanTwoValues) {
1977       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1978       for (unsigned i = 0; i < NumElems; ++i) {
1979         SDValue V = Node->getOperand(i);
1980         if (V.isUndef())
1981           continue;
1982         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1983       }
1984       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1985         // Get the splatted value into the low element of a vector register.
1986         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1987         SDValue Vec2;
1988         if (Value2.getNode())
1989           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
1990         else
1991           Vec2 = DAG.getUNDEF(VT);
1992 
1993         // Return shuffle(LowValVec, undef, <0,0,0,0>)
1994         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1995       }
1996     } else {
1997       SDValue Res;
1998       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
1999         return Res;
2000     }
2001   }
2002 
2003   // Otherwise, we can't handle this case efficiently.
2004   return ExpandVectorBuildThroughStack(Node);
2005 }
2006 
2007 SDValue SelectionDAGLegalize::ExpandSPLAT_VECTOR(SDNode *Node) {
2008   SDLoc DL(Node);
2009   EVT VT = Node->getValueType(0);
2010   SDValue SplatVal = Node->getOperand(0);
2011 
2012   return DAG.getSplatBuildVector(VT, DL, SplatVal);
2013 }
2014 
2015 // Expand a node into a call to a libcall.  If the result value
2016 // does not fit into a register, return the lo part and set the hi part to the
2017 // by-reg argument.  If it does fit into a single register, return the result
2018 // and leave the Hi part unset.
2019 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
2020                                             bool isSigned) {
2021   TargetLowering::ArgListTy Args;
2022   TargetLowering::ArgListEntry Entry;
2023   for (const SDValue &Op : Node->op_values()) {
2024     EVT ArgVT = Op.getValueType();
2025     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2026     Entry.Node = Op;
2027     Entry.Ty = ArgTy;
2028     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2029     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2030     Args.push_back(Entry);
2031   }
2032   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2033                                          TLI.getPointerTy(DAG.getDataLayout()));
2034 
2035   EVT RetVT = Node->getValueType(0);
2036   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2037 
2038   // By default, the input chain to this libcall is the entry node of the
2039   // function. If the libcall is going to be emitted as a tail call then
2040   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2041   // node which is being folded has a non-entry input chain.
2042   SDValue InChain = DAG.getEntryNode();
2043 
2044   // isTailCall may be true since the callee does not reference caller stack
2045   // frame. Check if it's in the right position and that the return types match.
2046   SDValue TCChain = InChain;
2047   const Function &F = DAG.getMachineFunction().getFunction();
2048   bool isTailCall =
2049       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2050       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2051   if (isTailCall)
2052     InChain = TCChain;
2053 
2054   TargetLowering::CallLoweringInfo CLI(DAG);
2055   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2056   CLI.setDebugLoc(SDLoc(Node))
2057       .setChain(InChain)
2058       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2059                     std::move(Args))
2060       .setTailCall(isTailCall)
2061       .setSExtResult(signExtend)
2062       .setZExtResult(!signExtend)
2063       .setIsPostTypeLegalization(true);
2064 
2065   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2066 
2067   if (!CallInfo.second.getNode()) {
2068     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump(&DAG));
2069     // It's a tailcall, return the chain (which is the DAG root).
2070     return DAG.getRoot();
2071   }
2072 
2073   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump(&DAG));
2074   return CallInfo.first;
2075 }
2076 
2077 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2078                                            RTLIB::Libcall LC,
2079                                            SmallVectorImpl<SDValue> &Results) {
2080   if (LC == RTLIB::UNKNOWN_LIBCALL)
2081     llvm_unreachable("Can't create an unknown libcall!");
2082 
2083   if (Node->isStrictFPOpcode()) {
2084     EVT RetVT = Node->getValueType(0);
2085     SmallVector<SDValue, 4> Ops(drop_begin(Node->ops()));
2086     TargetLowering::MakeLibCallOptions CallOptions;
2087     // FIXME: This doesn't support tail calls.
2088     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2089                                                       Ops, CallOptions,
2090                                                       SDLoc(Node),
2091                                                       Node->getOperand(0));
2092     Results.push_back(Tmp.first);
2093     Results.push_back(Tmp.second);
2094   } else {
2095     SDValue Tmp = ExpandLibCall(LC, Node, false);
2096     Results.push_back(Tmp);
2097   }
2098 }
2099 
2100 /// Expand the node to a libcall based on the result type.
2101 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2102                                            RTLIB::Libcall Call_F32,
2103                                            RTLIB::Libcall Call_F64,
2104                                            RTLIB::Libcall Call_F80,
2105                                            RTLIB::Libcall Call_F128,
2106                                            RTLIB::Libcall Call_PPCF128,
2107                                            SmallVectorImpl<SDValue> &Results) {
2108   RTLIB::Libcall LC = RTLIB::getFPLibCall(Node->getSimpleValueType(0),
2109                                           Call_F32, Call_F64, Call_F80,
2110                                           Call_F128, Call_PPCF128);
2111   ExpandFPLibCall(Node, LC, Results);
2112 }
2113 
2114 SDValue SelectionDAGLegalize::ExpandIntLibCall(
2115     SDNode *Node, bool isSigned, RTLIB::Libcall Call_I8,
2116     RTLIB::Libcall Call_I16, RTLIB::Libcall Call_I32, RTLIB::Libcall Call_I64,
2117     RTLIB::Libcall Call_I128, RTLIB::Libcall Call_IEXT) {
2118   RTLIB::Libcall LC;
2119   switch (Node->getSimpleValueType(0).SimpleTy) {
2120 
2121   default:
2122     LC = Call_IEXT;
2123     break;
2124 
2125   case MVT::i8:   LC = Call_I8; break;
2126   case MVT::i16:  LC = Call_I16; break;
2127   case MVT::i32:  LC = Call_I32; break;
2128   case MVT::i64:  LC = Call_I64; break;
2129   case MVT::i128: LC = Call_I128; break;
2130   }
2131   return ExpandLibCall(LC, Node, isSigned);
2132 }
2133 
2134 /// Expand the node to a libcall based on first argument type (for instance
2135 /// lround and its variant).
2136 void SelectionDAGLegalize::ExpandArgFPLibCall(SDNode* Node,
2137                                             RTLIB::Libcall Call_F32,
2138                                             RTLIB::Libcall Call_F64,
2139                                             RTLIB::Libcall Call_F80,
2140                                             RTLIB::Libcall Call_F128,
2141                                             RTLIB::Libcall Call_PPCF128,
2142                                             SmallVectorImpl<SDValue> &Results) {
2143   EVT InVT = Node->getOperand(Node->isStrictFPOpcode() ? 1 : 0).getValueType();
2144   RTLIB::Libcall LC = RTLIB::getFPLibCall(InVT.getSimpleVT(),
2145                                           Call_F32, Call_F64, Call_F80,
2146                                           Call_F128, Call_PPCF128);
2147   ExpandFPLibCall(Node, LC, Results);
2148 }
2149 
2150 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2151 void
2152 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2153                                           SmallVectorImpl<SDValue> &Results) {
2154   unsigned Opcode = Node->getOpcode();
2155   bool isSigned = Opcode == ISD::SDIVREM;
2156 
2157   RTLIB::Libcall LC;
2158   switch (Node->getSimpleValueType(0).SimpleTy) {
2159 
2160   default:
2161     LC = isSigned ? RTLIB::SDIVREM_IEXT : RTLIB::UDIVREM_IEXT;
2162     break;
2163 
2164   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2165   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2166   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2167   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2168   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2169   }
2170 
2171   // The input chain to this libcall is the entry node of the function.
2172   // Legalizing the call will automatically add the previous call to the
2173   // dependence.
2174   SDValue InChain = DAG.getEntryNode();
2175 
2176   EVT RetVT = Node->getValueType(0);
2177   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2178 
2179   TargetLowering::ArgListTy Args;
2180   TargetLowering::ArgListEntry Entry;
2181   for (const SDValue &Op : Node->op_values()) {
2182     EVT ArgVT = Op.getValueType();
2183     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2184     Entry.Node = Op;
2185     Entry.Ty = ArgTy;
2186     Entry.IsSExt = isSigned;
2187     Entry.IsZExt = !isSigned;
2188     Args.push_back(Entry);
2189   }
2190 
2191   // Also pass the return address of the remainder.
2192   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2193   Entry.Node = FIPtr;
2194   Entry.Ty = RetTy->getPointerTo();
2195   Entry.IsSExt = isSigned;
2196   Entry.IsZExt = !isSigned;
2197   Args.push_back(Entry);
2198 
2199   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2200                                          TLI.getPointerTy(DAG.getDataLayout()));
2201 
2202   SDLoc dl(Node);
2203   TargetLowering::CallLoweringInfo CLI(DAG);
2204   CLI.setDebugLoc(dl)
2205       .setChain(InChain)
2206       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2207                     std::move(Args))
2208       .setSExtResult(isSigned)
2209       .setZExtResult(!isSigned);
2210 
2211   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2212 
2213   // Remainder is loaded back from the stack frame.
2214   SDValue Rem =
2215       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2216   Results.push_back(CallInfo.first);
2217   Results.push_back(Rem);
2218 }
2219 
2220 /// Return true if sincos libcall is available.
2221 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2222   RTLIB::Libcall LC;
2223   switch (Node->getSimpleValueType(0).SimpleTy) {
2224   default: llvm_unreachable("Unexpected request for libcall!");
2225   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2226   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2227   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2228   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2229   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2230   }
2231   return TLI.getLibcallName(LC) != nullptr;
2232 }
2233 
2234 /// Only issue sincos libcall if both sin and cos are needed.
2235 static bool useSinCos(SDNode *Node) {
2236   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2237     ? ISD::FCOS : ISD::FSIN;
2238 
2239   SDValue Op0 = Node->getOperand(0);
2240   for (const SDNode *User : Op0.getNode()->uses()) {
2241     if (User == Node)
2242       continue;
2243     // The other user might have been turned into sincos already.
2244     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2245       return true;
2246   }
2247   return false;
2248 }
2249 
2250 /// Issue libcalls to sincos to compute sin / cos pairs.
2251 void
2252 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2253                                           SmallVectorImpl<SDValue> &Results) {
2254   RTLIB::Libcall LC;
2255   switch (Node->getSimpleValueType(0).SimpleTy) {
2256   default: llvm_unreachable("Unexpected request for libcall!");
2257   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2258   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2259   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2260   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2261   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2262   }
2263 
2264   // The input chain to this libcall is the entry node of the function.
2265   // Legalizing the call will automatically add the previous call to the
2266   // dependence.
2267   SDValue InChain = DAG.getEntryNode();
2268 
2269   EVT RetVT = Node->getValueType(0);
2270   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2271 
2272   TargetLowering::ArgListTy Args;
2273   TargetLowering::ArgListEntry Entry;
2274 
2275   // Pass the argument.
2276   Entry.Node = Node->getOperand(0);
2277   Entry.Ty = RetTy;
2278   Entry.IsSExt = false;
2279   Entry.IsZExt = false;
2280   Args.push_back(Entry);
2281 
2282   // Pass the return address of sin.
2283   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2284   Entry.Node = SinPtr;
2285   Entry.Ty = RetTy->getPointerTo();
2286   Entry.IsSExt = false;
2287   Entry.IsZExt = false;
2288   Args.push_back(Entry);
2289 
2290   // Also pass the return address of the cos.
2291   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2292   Entry.Node = CosPtr;
2293   Entry.Ty = RetTy->getPointerTo();
2294   Entry.IsSExt = false;
2295   Entry.IsZExt = false;
2296   Args.push_back(Entry);
2297 
2298   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2299                                          TLI.getPointerTy(DAG.getDataLayout()));
2300 
2301   SDLoc dl(Node);
2302   TargetLowering::CallLoweringInfo CLI(DAG);
2303   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2304       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2305       std::move(Args));
2306 
2307   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2308 
2309   Results.push_back(
2310       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2311   Results.push_back(
2312       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2313 }
2314 
2315 /// This function is responsible for legalizing a
2316 /// INT_TO_FP operation of the specified operand when the target requests that
2317 /// we expand it.  At this point, we know that the result and operand types are
2318 /// legal for the target.
2319 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(SDNode *Node,
2320                                                    SDValue &Chain) {
2321   bool isSigned = (Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
2322                    Node->getOpcode() == ISD::SINT_TO_FP);
2323   EVT DestVT = Node->getValueType(0);
2324   SDLoc dl(Node);
2325   unsigned OpNo = Node->isStrictFPOpcode() ? 1 : 0;
2326   SDValue Op0 = Node->getOperand(OpNo);
2327   EVT SrcVT = Op0.getValueType();
2328 
2329   // TODO: Should any fast-math-flags be set for the created nodes?
2330   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2331   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64) &&
2332       (DestVT.bitsLE(MVT::f64) ||
2333        TLI.isOperationLegal(Node->isStrictFPOpcode() ? ISD::STRICT_FP_EXTEND
2334                                                      : ISD::FP_EXTEND,
2335                             DestVT))) {
2336     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2337                          "expansion\n");
2338 
2339     // Get the stack frame index of a 8 byte buffer.
2340     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2341 
2342     SDValue Lo = Op0;
2343     // if signed map to unsigned space
2344     if (isSigned) {
2345       // Invert sign bit (signed to unsigned mapping).
2346       Lo = DAG.getNode(ISD::XOR, dl, MVT::i32, Lo,
2347                        DAG.getConstant(0x80000000u, dl, MVT::i32));
2348     }
2349     // Initial hi portion of constructed double.
2350     SDValue Hi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2351 
2352     // If this a big endian target, swap the lo and high data.
2353     if (DAG.getDataLayout().isBigEndian())
2354       std::swap(Lo, Hi);
2355 
2356     SDValue MemChain = DAG.getEntryNode();
2357 
2358     // Store the lo of the constructed double.
2359     SDValue Store1 = DAG.getStore(MemChain, dl, Lo, StackSlot,
2360                                   MachinePointerInfo());
2361     // Store the hi of the constructed double.
2362     SDValue HiPtr = DAG.getMemBasePlusOffset(StackSlot, TypeSize::Fixed(4), dl);
2363     SDValue Store2 =
2364         DAG.getStore(MemChain, dl, Hi, HiPtr, MachinePointerInfo());
2365     MemChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
2366 
2367     // load the constructed double
2368     SDValue Load =
2369         DAG.getLoad(MVT::f64, dl, MemChain, StackSlot, MachinePointerInfo());
2370     // FP constant to bias correct the final result
2371     SDValue Bias = DAG.getConstantFP(isSigned ?
2372                                      BitsToDouble(0x4330000080000000ULL) :
2373                                      BitsToDouble(0x4330000000000000ULL),
2374                                      dl, MVT::f64);
2375     // Subtract the bias and get the final result.
2376     SDValue Sub;
2377     SDValue Result;
2378     if (Node->isStrictFPOpcode()) {
2379       Sub = DAG.getNode(ISD::STRICT_FSUB, dl, {MVT::f64, MVT::Other},
2380                         {Node->getOperand(0), Load, Bias});
2381       Chain = Sub.getValue(1);
2382       if (DestVT != Sub.getValueType()) {
2383         std::pair<SDValue, SDValue> ResultPair;
2384         ResultPair =
2385             DAG.getStrictFPExtendOrRound(Sub, Chain, dl, DestVT);
2386         Result = ResultPair.first;
2387         Chain = ResultPair.second;
2388       }
2389       else
2390         Result = Sub;
2391     } else {
2392       Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2393       Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2394     }
2395     return Result;
2396   }
2397 
2398   if (isSigned)
2399     return SDValue();
2400 
2401   // TODO: Generalize this for use with other types.
2402   if (((SrcVT == MVT::i32 || SrcVT == MVT::i64) && DestVT == MVT::f32) ||
2403       (SrcVT == MVT::i64 && DestVT == MVT::f64)) {
2404     LLVM_DEBUG(dbgs() << "Converting unsigned i32/i64 to f32/f64\n");
2405     // For unsigned conversions, convert them to signed conversions using the
2406     // algorithm from the x86_64 __floatundisf in compiler_rt. That method
2407     // should be valid for i32->f32 as well.
2408 
2409     // More generally this transform should be valid if there are 3 more bits
2410     // in the integer type than the significand. Rounding uses the first bit
2411     // after the width of the significand and the OR of all bits after that. So
2412     // we need to be able to OR the shifted out bit into one of the bits that
2413     // participate in the OR.
2414 
2415     // TODO: This really should be implemented using a branch rather than a
2416     // select.  We happen to get lucky and machinesink does the right
2417     // thing most of the time.  This would be a good candidate for a
2418     // pseudo-op, or, even better, for whole-function isel.
2419     EVT SetCCVT = getSetCCResultType(SrcVT);
2420 
2421     SDValue SignBitTest = DAG.getSetCC(
2422         dl, SetCCVT, Op0, DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2423 
2424     EVT ShiftVT = TLI.getShiftAmountTy(SrcVT, DAG.getDataLayout());
2425     SDValue ShiftConst = DAG.getConstant(1, dl, ShiftVT);
2426     SDValue Shr = DAG.getNode(ISD::SRL, dl, SrcVT, Op0, ShiftConst);
2427     SDValue AndConst = DAG.getConstant(1, dl, SrcVT);
2428     SDValue And = DAG.getNode(ISD::AND, dl, SrcVT, Op0, AndConst);
2429     SDValue Or = DAG.getNode(ISD::OR, dl, SrcVT, And, Shr);
2430 
2431     SDValue Slow, Fast;
2432     if (Node->isStrictFPOpcode()) {
2433       // In strict mode, we must avoid spurious exceptions, and therefore
2434       // must make sure to only emit a single STRICT_SINT_TO_FP.
2435       SDValue InCvt = DAG.getSelect(dl, SrcVT, SignBitTest, Or, Op0);
2436       Fast = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2437                          { Node->getOperand(0), InCvt });
2438       Slow = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2439                          { Fast.getValue(1), Fast, Fast });
2440       Chain = Slow.getValue(1);
2441       // The STRICT_SINT_TO_FP inherits the exception mode from the
2442       // incoming STRICT_UINT_TO_FP node; the STRICT_FADD node can
2443       // never raise any exception.
2444       SDNodeFlags Flags;
2445       Flags.setNoFPExcept(Node->getFlags().hasNoFPExcept());
2446       Fast->setFlags(Flags);
2447       Flags.setNoFPExcept(true);
2448       Slow->setFlags(Flags);
2449     } else {
2450       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Or);
2451       Slow = DAG.getNode(ISD::FADD, dl, DestVT, SignCvt, SignCvt);
2452       Fast = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2453     }
2454 
2455     return DAG.getSelect(dl, DestVT, SignBitTest, Slow, Fast);
2456   }
2457 
2458   // Don't expand it if there isn't cheap fadd.
2459   if (!TLI.isOperationLegalOrCustom(
2460           Node->isStrictFPOpcode() ? ISD::STRICT_FADD : ISD::FADD, DestVT))
2461     return SDValue();
2462 
2463   // The following optimization is valid only if every value in SrcVT (when
2464   // treated as signed) is representable in DestVT.  Check that the mantissa
2465   // size of DestVT is >= than the number of bits in SrcVT -1.
2466   assert(APFloat::semanticsPrecision(DAG.EVTToAPFloatSemantics(DestVT)) >=
2467              SrcVT.getSizeInBits() - 1 &&
2468          "Cannot perform lossless SINT_TO_FP!");
2469 
2470   SDValue Tmp1;
2471   if (Node->isStrictFPOpcode()) {
2472     Tmp1 = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2473                        { Node->getOperand(0), Op0 });
2474   } else
2475     Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2476 
2477   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2478                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2479   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2480           Four = DAG.getIntPtrConstant(4, dl);
2481   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2482                                     SignSet, Four, Zero);
2483 
2484   // If the sign bit of the integer is set, the large number will be treated
2485   // as a negative number.  To counteract this, the dynamic code adds an
2486   // offset depending on the data type.
2487   uint64_t FF;
2488   switch (SrcVT.getSimpleVT().SimpleTy) {
2489   default:
2490     return SDValue();
2491   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2492   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2493   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2494   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2495   }
2496   if (DAG.getDataLayout().isLittleEndian())
2497     FF <<= 32;
2498   Constant *FudgeFactor = ConstantInt::get(
2499                                        Type::getInt64Ty(*DAG.getContext()), FF);
2500 
2501   SDValue CPIdx =
2502       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2503   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
2504   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2505   Alignment = commonAlignment(Alignment, 4);
2506   SDValue FudgeInReg;
2507   if (DestVT == MVT::f32)
2508     FudgeInReg = DAG.getLoad(
2509         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2510         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2511         Alignment);
2512   else {
2513     SDValue Load = DAG.getExtLoad(
2514         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2515         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2516         Alignment);
2517     HandleSDNode Handle(Load);
2518     LegalizeOp(Load.getNode());
2519     FudgeInReg = Handle.getValue();
2520   }
2521 
2522   if (Node->isStrictFPOpcode()) {
2523     SDValue Result = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2524                                  { Tmp1.getValue(1), Tmp1, FudgeInReg });
2525     Chain = Result.getValue(1);
2526     return Result;
2527   }
2528 
2529   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2530 }
2531 
2532 /// This function is responsible for legalizing a
2533 /// *INT_TO_FP operation of the specified operand when the target requests that
2534 /// we promote it.  At this point, we know that the result and operand types are
2535 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2536 /// operation that takes a larger input.
2537 void SelectionDAGLegalize::PromoteLegalINT_TO_FP(
2538     SDNode *N, const SDLoc &dl, SmallVectorImpl<SDValue> &Results) {
2539   bool IsStrict = N->isStrictFPOpcode();
2540   bool IsSigned = N->getOpcode() == ISD::SINT_TO_FP ||
2541                   N->getOpcode() == ISD::STRICT_SINT_TO_FP;
2542   EVT DestVT = N->getValueType(0);
2543   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2544   unsigned UIntOp = IsStrict ? ISD::STRICT_UINT_TO_FP : ISD::UINT_TO_FP;
2545   unsigned SIntOp = IsStrict ? ISD::STRICT_SINT_TO_FP : ISD::SINT_TO_FP;
2546 
2547   // First step, figure out the appropriate *INT_TO_FP operation to use.
2548   EVT NewInTy = LegalOp.getValueType();
2549 
2550   unsigned OpToUse = 0;
2551 
2552   // Scan for the appropriate larger type to use.
2553   while (true) {
2554     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2555     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2556 
2557     // If the target supports SINT_TO_FP of this type, use it.
2558     if (TLI.isOperationLegalOrCustom(SIntOp, NewInTy)) {
2559       OpToUse = SIntOp;
2560       break;
2561     }
2562     if (IsSigned)
2563       continue;
2564 
2565     // If the target supports UINT_TO_FP of this type, use it.
2566     if (TLI.isOperationLegalOrCustom(UIntOp, NewInTy)) {
2567       OpToUse = UIntOp;
2568       break;
2569     }
2570 
2571     // Otherwise, try a larger type.
2572   }
2573 
2574   // Okay, we found the operation and type to use.  Zero extend our input to the
2575   // desired type then run the operation on it.
2576   if (IsStrict) {
2577     SDValue Res =
2578         DAG.getNode(OpToUse, dl, {DestVT, MVT::Other},
2579                     {N->getOperand(0),
2580                      DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2581                                  dl, NewInTy, LegalOp)});
2582     Results.push_back(Res);
2583     Results.push_back(Res.getValue(1));
2584     return;
2585   }
2586 
2587   Results.push_back(
2588       DAG.getNode(OpToUse, dl, DestVT,
2589                   DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2590                               dl, NewInTy, LegalOp)));
2591 }
2592 
2593 /// This function is responsible for legalizing a
2594 /// FP_TO_*INT operation of the specified operand when the target requests that
2595 /// we promote it.  At this point, we know that the result and operand types are
2596 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2597 /// operation that returns a larger result.
2598 void SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
2599                                                  SmallVectorImpl<SDValue> &Results) {
2600   bool IsStrict = N->isStrictFPOpcode();
2601   bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT ||
2602                   N->getOpcode() == ISD::STRICT_FP_TO_SINT;
2603   EVT DestVT = N->getValueType(0);
2604   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2605   // First step, figure out the appropriate FP_TO*INT operation to use.
2606   EVT NewOutTy = DestVT;
2607 
2608   unsigned OpToUse = 0;
2609 
2610   // Scan for the appropriate larger type to use.
2611   while (true) {
2612     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2613     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2614 
2615     // A larger signed type can hold all unsigned values of the requested type,
2616     // so using FP_TO_SINT is valid
2617     OpToUse = IsStrict ? ISD::STRICT_FP_TO_SINT : ISD::FP_TO_SINT;
2618     if (TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2619       break;
2620 
2621     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2622     OpToUse = IsStrict ? ISD::STRICT_FP_TO_UINT : ISD::FP_TO_UINT;
2623     if (!IsSigned && TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2624       break;
2625 
2626     // Otherwise, try a larger type.
2627   }
2628 
2629   // Okay, we found the operation and type to use.
2630   SDValue Operation;
2631   if (IsStrict) {
2632     SDVTList VTs = DAG.getVTList(NewOutTy, MVT::Other);
2633     Operation = DAG.getNode(OpToUse, dl, VTs, N->getOperand(0), LegalOp);
2634   } else
2635     Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2636 
2637   // Truncate the result of the extended FP_TO_*INT operation to the desired
2638   // size.
2639   SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2640   Results.push_back(Trunc);
2641   if (IsStrict)
2642     Results.push_back(Operation.getValue(1));
2643 }
2644 
2645 /// Promote FP_TO_*INT_SAT operation to a larger result type. At this point
2646 /// the result and operand types are legal and there must be a legal
2647 /// FP_TO_*INT_SAT operation for a larger result type.
2648 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT_SAT(SDNode *Node,
2649                                                         const SDLoc &dl) {
2650   unsigned Opcode = Node->getOpcode();
2651 
2652   // Scan for the appropriate larger type to use.
2653   EVT NewOutTy = Node->getValueType(0);
2654   while (true) {
2655     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy + 1);
2656     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2657 
2658     if (TLI.isOperationLegalOrCustom(Opcode, NewOutTy))
2659       break;
2660   }
2661 
2662   // Saturation width is determined by second operand, so we don't have to
2663   // perform any fixup and can directly truncate the result.
2664   SDValue Result = DAG.getNode(Opcode, dl, NewOutTy, Node->getOperand(0),
2665                                Node->getOperand(1));
2666   return DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Result);
2667 }
2668 
2669 /// Open code the operations for PARITY of the specified operation.
2670 SDValue SelectionDAGLegalize::ExpandPARITY(SDValue Op, const SDLoc &dl) {
2671   EVT VT = Op.getValueType();
2672   EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2673   unsigned Sz = VT.getScalarSizeInBits();
2674 
2675   // If CTPOP is legal, use it. Otherwise use shifts and xor.
2676   SDValue Result;
2677   if (TLI.isOperationLegalOrPromote(ISD::CTPOP, VT)) {
2678     Result = DAG.getNode(ISD::CTPOP, dl, VT, Op);
2679   } else {
2680     Result = Op;
2681     for (unsigned i = Log2_32_Ceil(Sz); i != 0;) {
2682       SDValue Shift = DAG.getNode(ISD::SRL, dl, VT, Result,
2683                                   DAG.getConstant(1ULL << (--i), dl, ShVT));
2684       Result = DAG.getNode(ISD::XOR, dl, VT, Result, Shift);
2685     }
2686   }
2687 
2688   return DAG.getNode(ISD::AND, dl, VT, Result, DAG.getConstant(1, dl, VT));
2689 }
2690 
2691 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2692   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2693   SmallVector<SDValue, 8> Results;
2694   SDLoc dl(Node);
2695   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2696   bool NeedInvert;
2697   switch (Node->getOpcode()) {
2698   case ISD::ABS:
2699     if ((Tmp1 = TLI.expandABS(Node, DAG)))
2700       Results.push_back(Tmp1);
2701     break;
2702   case ISD::CTPOP:
2703     if ((Tmp1 = TLI.expandCTPOP(Node, DAG)))
2704       Results.push_back(Tmp1);
2705     break;
2706   case ISD::CTLZ:
2707   case ISD::CTLZ_ZERO_UNDEF:
2708     if ((Tmp1 = TLI.expandCTLZ(Node, DAG)))
2709       Results.push_back(Tmp1);
2710     break;
2711   case ISD::CTTZ:
2712   case ISD::CTTZ_ZERO_UNDEF:
2713     if ((Tmp1 = TLI.expandCTTZ(Node, DAG)))
2714       Results.push_back(Tmp1);
2715     break;
2716   case ISD::BITREVERSE:
2717     if ((Tmp1 = TLI.expandBITREVERSE(Node, DAG)))
2718       Results.push_back(Tmp1);
2719     break;
2720   case ISD::BSWAP:
2721     if ((Tmp1 = TLI.expandBSWAP(Node, DAG)))
2722       Results.push_back(Tmp1);
2723     break;
2724   case ISD::PARITY:
2725     Results.push_back(ExpandPARITY(Node->getOperand(0), dl));
2726     break;
2727   case ISD::FRAMEADDR:
2728   case ISD::RETURNADDR:
2729   case ISD::FRAME_TO_ARGS_OFFSET:
2730     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2731     break;
2732   case ISD::EH_DWARF_CFA: {
2733     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2734                                         TLI.getPointerTy(DAG.getDataLayout()));
2735     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2736                                  CfaArg.getValueType(),
2737                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2738                                              CfaArg.getValueType()),
2739                                  CfaArg);
2740     SDValue FA = DAG.getNode(
2741         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2742         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2743     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2744                                   FA, Offset));
2745     break;
2746   }
2747   case ISD::FLT_ROUNDS_:
2748     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2749     Results.push_back(Node->getOperand(0));
2750     break;
2751   case ISD::EH_RETURN:
2752   case ISD::EH_LABEL:
2753   case ISD::PREFETCH:
2754   case ISD::VAEND:
2755   case ISD::EH_SJLJ_LONGJMP:
2756     // If the target didn't expand these, there's nothing to do, so just
2757     // preserve the chain and be done.
2758     Results.push_back(Node->getOperand(0));
2759     break;
2760   case ISD::READCYCLECOUNTER:
2761     // If the target didn't expand this, just return 'zero' and preserve the
2762     // chain.
2763     Results.append(Node->getNumValues() - 1,
2764                    DAG.getConstant(0, dl, Node->getValueType(0)));
2765     Results.push_back(Node->getOperand(0));
2766     break;
2767   case ISD::EH_SJLJ_SETJMP:
2768     // If the target didn't expand this, just return 'zero' and preserve the
2769     // chain.
2770     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2771     Results.push_back(Node->getOperand(0));
2772     break;
2773   case ISD::ATOMIC_LOAD: {
2774     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2775     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2776     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2777     SDValue Swap = DAG.getAtomicCmpSwap(
2778         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2779         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2780         cast<AtomicSDNode>(Node)->getMemOperand());
2781     Results.push_back(Swap.getValue(0));
2782     Results.push_back(Swap.getValue(1));
2783     break;
2784   }
2785   case ISD::ATOMIC_STORE: {
2786     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2787     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2788                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2789                                  Node->getOperand(0),
2790                                  Node->getOperand(1), Node->getOperand(2),
2791                                  cast<AtomicSDNode>(Node)->getMemOperand());
2792     Results.push_back(Swap.getValue(1));
2793     break;
2794   }
2795   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2796     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2797     // splits out the success value as a comparison. Expanding the resulting
2798     // ATOMIC_CMP_SWAP will produce a libcall.
2799     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2800     SDValue Res = DAG.getAtomicCmpSwap(
2801         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2802         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2803         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2804 
2805     SDValue ExtRes = Res;
2806     SDValue LHS = Res;
2807     SDValue RHS = Node->getOperand(1);
2808 
2809     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2810     EVT OuterType = Node->getValueType(0);
2811     switch (TLI.getExtendForAtomicOps()) {
2812     case ISD::SIGN_EXTEND:
2813       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2814                         DAG.getValueType(AtomicType));
2815       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2816                         Node->getOperand(2), DAG.getValueType(AtomicType));
2817       ExtRes = LHS;
2818       break;
2819     case ISD::ZERO_EXTEND:
2820       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2821                         DAG.getValueType(AtomicType));
2822       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2823       ExtRes = LHS;
2824       break;
2825     case ISD::ANY_EXTEND:
2826       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2827       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2828       break;
2829     default:
2830       llvm_unreachable("Invalid atomic op extension");
2831     }
2832 
2833     SDValue Success =
2834         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2835 
2836     Results.push_back(ExtRes.getValue(0));
2837     Results.push_back(Success);
2838     Results.push_back(Res.getValue(1));
2839     break;
2840   }
2841   case ISD::DYNAMIC_STACKALLOC:
2842     ExpandDYNAMIC_STACKALLOC(Node, Results);
2843     break;
2844   case ISD::MERGE_VALUES:
2845     for (unsigned i = 0; i < Node->getNumValues(); i++)
2846       Results.push_back(Node->getOperand(i));
2847     break;
2848   case ISD::UNDEF: {
2849     EVT VT = Node->getValueType(0);
2850     if (VT.isInteger())
2851       Results.push_back(DAG.getConstant(0, dl, VT));
2852     else {
2853       assert(VT.isFloatingPoint() && "Unknown value type!");
2854       Results.push_back(DAG.getConstantFP(0, dl, VT));
2855     }
2856     break;
2857   }
2858   case ISD::STRICT_FP_ROUND:
2859     // When strict mode is enforced we can't do expansion because it
2860     // does not honor the "strict" properties. Only libcall is allowed.
2861     if (TLI.isStrictFPEnabled())
2862       break;
2863     // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
2864     // since this operation is more efficient than stack operation.
2865     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2866                                        Node->getValueType(0))
2867         == TargetLowering::Legal)
2868       break;
2869     // We fall back to use stack operation when the FP_ROUND operation
2870     // isn't available.
2871     if ((Tmp1 = EmitStackConvert(Node->getOperand(1), Node->getValueType(0),
2872                                  Node->getValueType(0), dl,
2873                                  Node->getOperand(0)))) {
2874       ReplaceNode(Node, Tmp1.getNode());
2875       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_ROUND node\n");
2876       return true;
2877     }
2878     break;
2879   case ISD::FP_ROUND:
2880   case ISD::BITCAST:
2881     if ((Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
2882                                  Node->getValueType(0), dl)))
2883       Results.push_back(Tmp1);
2884     break;
2885   case ISD::STRICT_FP_EXTEND:
2886     // When strict mode is enforced we can't do expansion because it
2887     // does not honor the "strict" properties. Only libcall is allowed.
2888     if (TLI.isStrictFPEnabled())
2889       break;
2890     // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
2891     // since this operation is more efficient than stack operation.
2892     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2893                                        Node->getValueType(0))
2894         == TargetLowering::Legal)
2895       break;
2896     // We fall back to use stack operation when the FP_EXTEND operation
2897     // isn't available.
2898     if ((Tmp1 = EmitStackConvert(
2899              Node->getOperand(1), Node->getOperand(1).getValueType(),
2900              Node->getValueType(0), dl, Node->getOperand(0)))) {
2901       ReplaceNode(Node, Tmp1.getNode());
2902       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_EXTEND node\n");
2903       return true;
2904     }
2905     break;
2906   case ISD::FP_EXTEND:
2907     if ((Tmp1 = EmitStackConvert(Node->getOperand(0),
2908                                  Node->getOperand(0).getValueType(),
2909                                  Node->getValueType(0), dl)))
2910       Results.push_back(Tmp1);
2911     break;
2912   case ISD::BF16_TO_FP: {
2913     // Always expand bf16 to f32 casts, they lower to ext + shift.
2914     SDValue Op = DAG.getNode(ISD::BITCAST, dl, MVT::i16, Node->getOperand(0));
2915     Op = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i32, Op);
2916     Op = DAG.getNode(
2917         ISD::SHL, dl, MVT::i32, Op,
2918         DAG.getConstant(16, dl,
2919                         TLI.getShiftAmountTy(MVT::i32, DAG.getDataLayout())));
2920     Op = DAG.getNode(ISD::BITCAST, dl, MVT::f32, Op);
2921     Results.push_back(Op);
2922     break;
2923   }
2924   case ISD::SIGN_EXTEND_INREG: {
2925     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2926     EVT VT = Node->getValueType(0);
2927 
2928     // An in-register sign-extend of a boolean is a negation:
2929     // 'true' (1) sign-extended is -1.
2930     // 'false' (0) sign-extended is 0.
2931     // However, we must mask the high bits of the source operand because the
2932     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
2933 
2934     // TODO: Do this for vectors too?
2935     if (ExtraVT.isScalarInteger() && ExtraVT.getSizeInBits() == 1) {
2936       SDValue One = DAG.getConstant(1, dl, VT);
2937       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
2938       SDValue Zero = DAG.getConstant(0, dl, VT);
2939       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
2940       Results.push_back(Neg);
2941       break;
2942     }
2943 
2944     // NOTE: we could fall back on load/store here too for targets without
2945     // SRA.  However, it is doubtful that any exist.
2946     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2947     unsigned BitsDiff = VT.getScalarSizeInBits() -
2948                         ExtraVT.getScalarSizeInBits();
2949     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
2950     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
2951                        Node->getOperand(0), ShiftCst);
2952     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
2953     Results.push_back(Tmp1);
2954     break;
2955   }
2956   case ISD::UINT_TO_FP:
2957   case ISD::STRICT_UINT_TO_FP:
2958     if (TLI.expandUINT_TO_FP(Node, Tmp1, Tmp2, DAG)) {
2959       Results.push_back(Tmp1);
2960       if (Node->isStrictFPOpcode())
2961         Results.push_back(Tmp2);
2962       break;
2963     }
2964     LLVM_FALLTHROUGH;
2965   case ISD::SINT_TO_FP:
2966   case ISD::STRICT_SINT_TO_FP:
2967     if ((Tmp1 = ExpandLegalINT_TO_FP(Node, Tmp2))) {
2968       Results.push_back(Tmp1);
2969       if (Node->isStrictFPOpcode())
2970         Results.push_back(Tmp2);
2971     }
2972     break;
2973   case ISD::FP_TO_SINT:
2974     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
2975       Results.push_back(Tmp1);
2976     break;
2977   case ISD::STRICT_FP_TO_SINT:
2978     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG)) {
2979       ReplaceNode(Node, Tmp1.getNode());
2980       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_SINT node\n");
2981       return true;
2982     }
2983     break;
2984   case ISD::FP_TO_UINT:
2985     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG))
2986       Results.push_back(Tmp1);
2987     break;
2988   case ISD::STRICT_FP_TO_UINT:
2989     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG)) {
2990       // Relink the chain.
2991       DAG.ReplaceAllUsesOfValueWith(SDValue(Node,1), Tmp2);
2992       // Replace the new UINT result.
2993       ReplaceNodeWithValue(SDValue(Node, 0), Tmp1);
2994       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_UINT node\n");
2995       return true;
2996     }
2997     break;
2998   case ISD::FP_TO_SINT_SAT:
2999   case ISD::FP_TO_UINT_SAT:
3000     Results.push_back(TLI.expandFP_TO_INT_SAT(Node, DAG));
3001     break;
3002   case ISD::VAARG:
3003     Results.push_back(DAG.expandVAArg(Node));
3004     Results.push_back(Results[0].getValue(1));
3005     break;
3006   case ISD::VACOPY:
3007     Results.push_back(DAG.expandVACopy(Node));
3008     break;
3009   case ISD::EXTRACT_VECTOR_ELT:
3010     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
3011       // This must be an access of the only element.  Return it.
3012       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
3013                          Node->getOperand(0));
3014     else
3015       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
3016     Results.push_back(Tmp1);
3017     break;
3018   case ISD::EXTRACT_SUBVECTOR:
3019     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
3020     break;
3021   case ISD::INSERT_SUBVECTOR:
3022     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3023     break;
3024   case ISD::CONCAT_VECTORS:
3025     Results.push_back(ExpandVectorBuildThroughStack(Node));
3026     break;
3027   case ISD::SCALAR_TO_VECTOR:
3028     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3029     break;
3030   case ISD::INSERT_VECTOR_ELT:
3031     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3032                                               Node->getOperand(1),
3033                                               Node->getOperand(2), dl));
3034     break;
3035   case ISD::VECTOR_SHUFFLE: {
3036     SmallVector<int, 32> NewMask;
3037     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3038 
3039     EVT VT = Node->getValueType(0);
3040     EVT EltVT = VT.getVectorElementType();
3041     SDValue Op0 = Node->getOperand(0);
3042     SDValue Op1 = Node->getOperand(1);
3043     if (!TLI.isTypeLegal(EltVT)) {
3044       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3045 
3046       // BUILD_VECTOR operands are allowed to be wider than the element type.
3047       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3048       // it.
3049       if (NewEltVT.bitsLT(EltVT)) {
3050         // Convert shuffle node.
3051         // If original node was v4i64 and the new EltVT is i32,
3052         // cast operands to v8i32 and re-build the mask.
3053 
3054         // Calculate new VT, the size of the new VT should be equal to original.
3055         EVT NewVT =
3056             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3057                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3058         assert(NewVT.bitsEq(VT));
3059 
3060         // cast operands to new VT
3061         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3062         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3063 
3064         // Convert the shuffle mask
3065         unsigned int factor =
3066                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3067 
3068         // EltVT gets smaller
3069         assert(factor > 0);
3070 
3071         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3072           if (Mask[i] < 0) {
3073             for (unsigned fi = 0; fi < factor; ++fi)
3074               NewMask.push_back(Mask[i]);
3075           }
3076           else {
3077             for (unsigned fi = 0; fi < factor; ++fi)
3078               NewMask.push_back(Mask[i]*factor+fi);
3079           }
3080         }
3081         Mask = NewMask;
3082         VT = NewVT;
3083       }
3084       EltVT = NewEltVT;
3085     }
3086     unsigned NumElems = VT.getVectorNumElements();
3087     SmallVector<SDValue, 16> Ops;
3088     for (unsigned i = 0; i != NumElems; ++i) {
3089       if (Mask[i] < 0) {
3090         Ops.push_back(DAG.getUNDEF(EltVT));
3091         continue;
3092       }
3093       unsigned Idx = Mask[i];
3094       if (Idx < NumElems)
3095         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3096                                   DAG.getVectorIdxConstant(Idx, dl)));
3097       else
3098         Ops.push_back(
3099             DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3100                         DAG.getVectorIdxConstant(Idx - NumElems, dl)));
3101     }
3102 
3103     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3104     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3105     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3106     Results.push_back(Tmp1);
3107     break;
3108   }
3109   case ISD::VECTOR_SPLICE: {
3110     Results.push_back(TLI.expandVectorSplice(Node, DAG));
3111     break;
3112   }
3113   case ISD::EXTRACT_ELEMENT: {
3114     EVT OpTy = Node->getOperand(0).getValueType();
3115     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3116       // 1 -> Hi
3117       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3118                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3119                                          TLI.getShiftAmountTy(
3120                                              Node->getOperand(0).getValueType(),
3121                                              DAG.getDataLayout())));
3122       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3123     } else {
3124       // 0 -> Lo
3125       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3126                          Node->getOperand(0));
3127     }
3128     Results.push_back(Tmp1);
3129     break;
3130   }
3131   case ISD::STACKSAVE:
3132     // Expand to CopyFromReg if the target set
3133     // StackPointerRegisterToSaveRestore.
3134     if (Register SP = TLI.getStackPointerRegisterToSaveRestore()) {
3135       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3136                                            Node->getValueType(0)));
3137       Results.push_back(Results[0].getValue(1));
3138     } else {
3139       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3140       Results.push_back(Node->getOperand(0));
3141     }
3142     break;
3143   case ISD::STACKRESTORE:
3144     // Expand to CopyToReg if the target set
3145     // StackPointerRegisterToSaveRestore.
3146     if (Register SP = TLI.getStackPointerRegisterToSaveRestore()) {
3147       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3148                                          Node->getOperand(1)));
3149     } else {
3150       Results.push_back(Node->getOperand(0));
3151     }
3152     break;
3153   case ISD::GET_DYNAMIC_AREA_OFFSET:
3154     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3155     Results.push_back(Results[0].getValue(0));
3156     break;
3157   case ISD::FCOPYSIGN:
3158     Results.push_back(ExpandFCOPYSIGN(Node));
3159     break;
3160   case ISD::FNEG:
3161     Results.push_back(ExpandFNEG(Node));
3162     break;
3163   case ISD::FABS:
3164     Results.push_back(ExpandFABS(Node));
3165     break;
3166   case ISD::IS_FPCLASS: {
3167     auto CNode = cast<ConstantSDNode>(Node->getOperand(1));
3168     auto Test = static_cast<FPClassTest>(CNode->getZExtValue());
3169     if (SDValue Expanded =
3170             TLI.expandIS_FPCLASS(Node->getValueType(0), Node->getOperand(0),
3171                                  Test, Node->getFlags(), SDLoc(Node), DAG))
3172       Results.push_back(Expanded);
3173     break;
3174   }
3175   case ISD::SMIN:
3176   case ISD::SMAX:
3177   case ISD::UMIN:
3178   case ISD::UMAX: {
3179     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3180     ISD::CondCode Pred;
3181     switch (Node->getOpcode()) {
3182     default: llvm_unreachable("How did we get here?");
3183     case ISD::SMAX: Pred = ISD::SETGT; break;
3184     case ISD::SMIN: Pred = ISD::SETLT; break;
3185     case ISD::UMAX: Pred = ISD::SETUGT; break;
3186     case ISD::UMIN: Pred = ISD::SETULT; break;
3187     }
3188     Tmp1 = Node->getOperand(0);
3189     Tmp2 = Node->getOperand(1);
3190     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3191     Results.push_back(Tmp1);
3192     break;
3193   }
3194   case ISD::FMINNUM:
3195   case ISD::FMAXNUM: {
3196     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3197       Results.push_back(Expanded);
3198     break;
3199   }
3200   case ISD::FSIN:
3201   case ISD::FCOS: {
3202     EVT VT = Node->getValueType(0);
3203     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3204     // fcos which share the same operand and both are used.
3205     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3206          isSinCosLibcallAvailable(Node, TLI))
3207         && useSinCos(Node)) {
3208       SDVTList VTs = DAG.getVTList(VT, VT);
3209       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3210       if (Node->getOpcode() == ISD::FCOS)
3211         Tmp1 = Tmp1.getValue(1);
3212       Results.push_back(Tmp1);
3213     }
3214     break;
3215   }
3216   case ISD::FMAD:
3217     llvm_unreachable("Illegal fmad should never be formed");
3218 
3219   case ISD::FP16_TO_FP:
3220     if (Node->getValueType(0) != MVT::f32) {
3221       // We can extend to types bigger than f32 in two steps without changing
3222       // the result. Since "f16 -> f32" is much more commonly available, give
3223       // CodeGen the option of emitting that before resorting to a libcall.
3224       SDValue Res =
3225           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3226       Results.push_back(
3227           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3228     }
3229     break;
3230   case ISD::STRICT_FP16_TO_FP:
3231     if (Node->getValueType(0) != MVT::f32) {
3232       // We can extend to types bigger than f32 in two steps without changing
3233       // the result. Since "f16 -> f32" is much more commonly available, give
3234       // CodeGen the option of emitting that before resorting to a libcall.
3235       SDValue Res =
3236           DAG.getNode(ISD::STRICT_FP16_TO_FP, dl, {MVT::f32, MVT::Other},
3237                       {Node->getOperand(0), Node->getOperand(1)});
3238       Res = DAG.getNode(ISD::STRICT_FP_EXTEND, dl,
3239                         {Node->getValueType(0), MVT::Other},
3240                         {Res.getValue(1), Res});
3241       Results.push_back(Res);
3242       Results.push_back(Res.getValue(1));
3243     }
3244     break;
3245   case ISD::FP_TO_FP16:
3246     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3247     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3248       SDValue Op = Node->getOperand(0);
3249       MVT SVT = Op.getSimpleValueType();
3250       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3251           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3252         // Under fastmath, we can expand this node into a fround followed by
3253         // a float-half conversion.
3254         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3255                                        DAG.getIntPtrConstant(0, dl));
3256         Results.push_back(
3257             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3258       }
3259     }
3260     break;
3261   case ISD::ConstantFP: {
3262     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3263     // Check to see if this FP immediate is already legal.
3264     // If this is a legal constant, turn it into a TargetConstantFP node.
3265     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0),
3266                           DAG.shouldOptForSize()))
3267       Results.push_back(ExpandConstantFP(CFP, true));
3268     break;
3269   }
3270   case ISD::Constant: {
3271     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3272     Results.push_back(ExpandConstant(CP));
3273     break;
3274   }
3275   case ISD::FSUB: {
3276     EVT VT = Node->getValueType(0);
3277     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3278         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3279       const SDNodeFlags Flags = Node->getFlags();
3280       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3281       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3282       Results.push_back(Tmp1);
3283     }
3284     break;
3285   }
3286   case ISD::SUB: {
3287     EVT VT = Node->getValueType(0);
3288     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3289            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3290            "Don't know how to expand this subtraction!");
3291     Tmp1 = DAG.getNOT(dl, Node->getOperand(1), VT);
3292     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3293     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3294     break;
3295   }
3296   case ISD::UREM:
3297   case ISD::SREM:
3298     if (TLI.expandREM(Node, Tmp1, DAG))
3299       Results.push_back(Tmp1);
3300     break;
3301   case ISD::UDIV:
3302   case ISD::SDIV: {
3303     bool isSigned = Node->getOpcode() == ISD::SDIV;
3304     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3305     EVT VT = Node->getValueType(0);
3306     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3307       SDVTList VTs = DAG.getVTList(VT, VT);
3308       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3309                          Node->getOperand(1));
3310       Results.push_back(Tmp1);
3311     }
3312     break;
3313   }
3314   case ISD::MULHU:
3315   case ISD::MULHS: {
3316     unsigned ExpandOpcode =
3317         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3318     EVT VT = Node->getValueType(0);
3319     SDVTList VTs = DAG.getVTList(VT, VT);
3320 
3321     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3322                        Node->getOperand(1));
3323     Results.push_back(Tmp1.getValue(1));
3324     break;
3325   }
3326   case ISD::UMUL_LOHI:
3327   case ISD::SMUL_LOHI: {
3328     SDValue LHS = Node->getOperand(0);
3329     SDValue RHS = Node->getOperand(1);
3330     MVT VT = LHS.getSimpleValueType();
3331     unsigned MULHOpcode =
3332         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3333 
3334     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3335       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3336       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3337       break;
3338     }
3339 
3340     SmallVector<SDValue, 4> Halves;
3341     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3342     assert(TLI.isTypeLegal(HalfType));
3343     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, dl, LHS, RHS, Halves,
3344                            HalfType, DAG,
3345                            TargetLowering::MulExpansionKind::Always)) {
3346       for (unsigned i = 0; i < 2; ++i) {
3347         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3348         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3349         SDValue Shift = DAG.getConstant(
3350             HalfType.getScalarSizeInBits(), dl,
3351             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3352         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3353         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3354       }
3355       break;
3356     }
3357     break;
3358   }
3359   case ISD::MUL: {
3360     EVT VT = Node->getValueType(0);
3361     SDVTList VTs = DAG.getVTList(VT, VT);
3362     // See if multiply or divide can be lowered using two-result operations.
3363     // We just need the low half of the multiply; try both the signed
3364     // and unsigned forms. If the target supports both SMUL_LOHI and
3365     // UMUL_LOHI, form a preference by checking which forms of plain
3366     // MULH it supports.
3367     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3368     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3369     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3370     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3371     unsigned OpToUse = 0;
3372     if (HasSMUL_LOHI && !HasMULHS) {
3373       OpToUse = ISD::SMUL_LOHI;
3374     } else if (HasUMUL_LOHI && !HasMULHU) {
3375       OpToUse = ISD::UMUL_LOHI;
3376     } else if (HasSMUL_LOHI) {
3377       OpToUse = ISD::SMUL_LOHI;
3378     } else if (HasUMUL_LOHI) {
3379       OpToUse = ISD::UMUL_LOHI;
3380     }
3381     if (OpToUse) {
3382       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3383                                     Node->getOperand(1)));
3384       break;
3385     }
3386 
3387     SDValue Lo, Hi;
3388     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3389     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3390         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3391         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3392         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3393         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3394                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3395       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3396       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3397       SDValue Shift =
3398           DAG.getConstant(HalfType.getSizeInBits(), dl,
3399                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3400       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3401       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3402     }
3403     break;
3404   }
3405   case ISD::FSHL:
3406   case ISD::FSHR:
3407     if (SDValue Expanded = TLI.expandFunnelShift(Node, DAG))
3408       Results.push_back(Expanded);
3409     break;
3410   case ISD::ROTL:
3411   case ISD::ROTR:
3412     if (SDValue Expanded = TLI.expandROT(Node, true /*AllowVectorOps*/, DAG))
3413       Results.push_back(Expanded);
3414     break;
3415   case ISD::SADDSAT:
3416   case ISD::UADDSAT:
3417   case ISD::SSUBSAT:
3418   case ISD::USUBSAT:
3419     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3420     break;
3421   case ISD::SSHLSAT:
3422   case ISD::USHLSAT:
3423     Results.push_back(TLI.expandShlSat(Node, DAG));
3424     break;
3425   case ISD::SMULFIX:
3426   case ISD::SMULFIXSAT:
3427   case ISD::UMULFIX:
3428   case ISD::UMULFIXSAT:
3429     Results.push_back(TLI.expandFixedPointMul(Node, DAG));
3430     break;
3431   case ISD::SDIVFIX:
3432   case ISD::SDIVFIXSAT:
3433   case ISD::UDIVFIX:
3434   case ISD::UDIVFIXSAT:
3435     if (SDValue V = TLI.expandFixedPointDiv(Node->getOpcode(), SDLoc(Node),
3436                                             Node->getOperand(0),
3437                                             Node->getOperand(1),
3438                                             Node->getConstantOperandVal(2),
3439                                             DAG)) {
3440       Results.push_back(V);
3441       break;
3442     }
3443     // FIXME: We might want to retry here with a wider type if we fail, if that
3444     // type is legal.
3445     // FIXME: Technically, so long as we only have sdivfixes where BW+Scale is
3446     // <= 128 (which is the case for all of the default Embedded-C types),
3447     // we will only get here with types and scales that we could always expand
3448     // if we were allowed to generate libcalls to division functions of illegal
3449     // type. But we cannot do that.
3450     llvm_unreachable("Cannot expand DIVFIX!");
3451   case ISD::ADDCARRY:
3452   case ISD::SUBCARRY: {
3453     SDValue LHS = Node->getOperand(0);
3454     SDValue RHS = Node->getOperand(1);
3455     SDValue Carry = Node->getOperand(2);
3456 
3457     bool IsAdd = Node->getOpcode() == ISD::ADDCARRY;
3458 
3459     // Initial add of the 2 operands.
3460     unsigned Op = IsAdd ? ISD::ADD : ISD::SUB;
3461     EVT VT = LHS.getValueType();
3462     SDValue Sum = DAG.getNode(Op, dl, VT, LHS, RHS);
3463 
3464     // Initial check for overflow.
3465     EVT CarryType = Node->getValueType(1);
3466     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3467     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3468     SDValue Overflow = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3469 
3470     // Add of the sum and the carry.
3471     SDValue One = DAG.getConstant(1, dl, VT);
3472     SDValue CarryExt =
3473         DAG.getNode(ISD::AND, dl, VT, DAG.getZExtOrTrunc(Carry, dl, VT), One);
3474     SDValue Sum2 = DAG.getNode(Op, dl, VT, Sum, CarryExt);
3475 
3476     // Second check for overflow. If we are adding, we can only overflow if the
3477     // initial sum is all 1s ang the carry is set, resulting in a new sum of 0.
3478     // If we are subtracting, we can only overflow if the initial sum is 0 and
3479     // the carry is set, resulting in a new sum of all 1s.
3480     SDValue Zero = DAG.getConstant(0, dl, VT);
3481     SDValue Overflow2 =
3482         IsAdd ? DAG.getSetCC(dl, SetCCType, Sum2, Zero, ISD::SETEQ)
3483               : DAG.getSetCC(dl, SetCCType, Sum, Zero, ISD::SETEQ);
3484     Overflow2 = DAG.getNode(ISD::AND, dl, SetCCType, Overflow2,
3485                             DAG.getZExtOrTrunc(Carry, dl, SetCCType));
3486 
3487     SDValue ResultCarry =
3488         DAG.getNode(ISD::OR, dl, SetCCType, Overflow, Overflow2);
3489 
3490     Results.push_back(Sum2);
3491     Results.push_back(DAG.getBoolExtOrTrunc(ResultCarry, dl, CarryType, VT));
3492     break;
3493   }
3494   case ISD::SADDO:
3495   case ISD::SSUBO: {
3496     SDValue Result, Overflow;
3497     TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
3498     Results.push_back(Result);
3499     Results.push_back(Overflow);
3500     break;
3501   }
3502   case ISD::UADDO:
3503   case ISD::USUBO: {
3504     SDValue Result, Overflow;
3505     TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
3506     Results.push_back(Result);
3507     Results.push_back(Overflow);
3508     break;
3509   }
3510   case ISD::UMULO:
3511   case ISD::SMULO: {
3512     SDValue Result, Overflow;
3513     if (TLI.expandMULO(Node, Result, Overflow, DAG)) {
3514       Results.push_back(Result);
3515       Results.push_back(Overflow);
3516     }
3517     break;
3518   }
3519   case ISD::BUILD_PAIR: {
3520     EVT PairTy = Node->getValueType(0);
3521     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3522     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3523     Tmp2 = DAG.getNode(
3524         ISD::SHL, dl, PairTy, Tmp2,
3525         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3526                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3527     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3528     break;
3529   }
3530   case ISD::SELECT:
3531     Tmp1 = Node->getOperand(0);
3532     Tmp2 = Node->getOperand(1);
3533     Tmp3 = Node->getOperand(2);
3534     if (Tmp1.getOpcode() == ISD::SETCC) {
3535       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3536                              Tmp2, Tmp3,
3537                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3538     } else {
3539       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3540                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3541                              Tmp2, Tmp3, ISD::SETNE);
3542     }
3543     Tmp1->setFlags(Node->getFlags());
3544     Results.push_back(Tmp1);
3545     break;
3546   case ISD::BR_JT: {
3547     SDValue Chain = Node->getOperand(0);
3548     SDValue Table = Node->getOperand(1);
3549     SDValue Index = Node->getOperand(2);
3550 
3551     const DataLayout &TD = DAG.getDataLayout();
3552     EVT PTy = TLI.getPointerTy(TD);
3553 
3554     unsigned EntrySize =
3555       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3556 
3557     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3558     // This transformation needs to be done here since otherwise the MIPS
3559     // backend will end up emitting a three instruction multiply sequence
3560     // instead of a single shift and MSP430 will call a runtime function.
3561     if (llvm::isPowerOf2_32(EntrySize))
3562       Index = DAG.getNode(
3563           ISD::SHL, dl, Index.getValueType(), Index,
3564           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3565     else
3566       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3567                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3568     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3569                                Index, Table);
3570 
3571     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3572     SDValue LD = DAG.getExtLoad(
3573         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3574         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3575     Addr = LD;
3576     if (TLI.isJumpTableRelative()) {
3577       // For PIC, the sequence is:
3578       // BRIND(load(Jumptable + index) + RelocBase)
3579       // RelocBase can be JumpTable, GOT or some sort of global base.
3580       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3581                           TLI.getPICJumpTableRelocBase(Table, DAG));
3582     }
3583 
3584     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3585     Results.push_back(Tmp1);
3586     break;
3587   }
3588   case ISD::BRCOND:
3589     // Expand brcond's setcc into its constituent parts and create a BR_CC
3590     // Node.
3591     Tmp1 = Node->getOperand(0);
3592     Tmp2 = Node->getOperand(1);
3593     if (Tmp2.getOpcode() == ISD::SETCC &&
3594         TLI.isOperationLegalOrCustom(ISD::BR_CC,
3595                                      Tmp2.getOperand(0).getValueType())) {
3596       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1, Tmp2.getOperand(2),
3597                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3598                          Node->getOperand(2));
3599     } else {
3600       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3601       if (Tmp2.isUndef() ||
3602           (Tmp2.getOpcode() == ISD::AND &&
3603            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3604            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3605         Tmp3 = Tmp2;
3606       else
3607         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3608                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3609       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3610                          DAG.getCondCode(ISD::SETNE), Tmp3,
3611                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3612                          Node->getOperand(2));
3613     }
3614     Results.push_back(Tmp1);
3615     break;
3616   case ISD::SETCC:
3617   case ISD::VP_SETCC:
3618   case ISD::STRICT_FSETCC:
3619   case ISD::STRICT_FSETCCS: {
3620     bool IsVP = Node->getOpcode() == ISD::VP_SETCC;
3621     bool IsStrict = Node->getOpcode() == ISD::STRICT_FSETCC ||
3622                     Node->getOpcode() == ISD::STRICT_FSETCCS;
3623     bool IsSignaling = Node->getOpcode() == ISD::STRICT_FSETCCS;
3624     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
3625     unsigned Offset = IsStrict ? 1 : 0;
3626     Tmp1 = Node->getOperand(0 + Offset);
3627     Tmp2 = Node->getOperand(1 + Offset);
3628     Tmp3 = Node->getOperand(2 + Offset);
3629     SDValue Mask, EVL;
3630     if (IsVP) {
3631       Mask = Node->getOperand(3 + Offset);
3632       EVL = Node->getOperand(4 + Offset);
3633     }
3634     bool Legalized = TLI.LegalizeSetCCCondCode(
3635         DAG, Node->getValueType(0), Tmp1, Tmp2, Tmp3, Mask, EVL, NeedInvert, dl,
3636         Chain, IsSignaling);
3637 
3638     if (Legalized) {
3639       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3640       // condition code, create a new SETCC node.
3641       if (Tmp3.getNode()) {
3642         if (IsStrict) {
3643           Tmp1 = DAG.getNode(Node->getOpcode(), dl, Node->getVTList(),
3644                              {Chain, Tmp1, Tmp2, Tmp3}, Node->getFlags());
3645           Chain = Tmp1.getValue(1);
3646         } else if (IsVP) {
3647           Tmp1 = DAG.getNode(Node->getOpcode(), dl, Node->getValueType(0),
3648                              {Tmp1, Tmp2, Tmp3, Mask, EVL}, Node->getFlags());
3649         } else {
3650           Tmp1 = DAG.getNode(Node->getOpcode(), dl, Node->getValueType(0), Tmp1,
3651                              Tmp2, Tmp3, Node->getFlags());
3652         }
3653       }
3654 
3655       // If we expanded the SETCC by inverting the condition code, then wrap
3656       // the existing SETCC in a NOT to restore the intended condition.
3657       if (NeedInvert) {
3658         if (!IsVP)
3659           Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3660         else
3661           Tmp1 =
3662               DAG.getVPLogicalNOT(dl, Tmp1, Mask, EVL, Tmp1->getValueType(0));
3663       }
3664 
3665       Results.push_back(Tmp1);
3666       if (IsStrict)
3667         Results.push_back(Chain);
3668 
3669       break;
3670     }
3671 
3672     // FIXME: It seems Legalized is false iff CCCode is Legal. I don't
3673     // understand if this code is useful for strict nodes.
3674     assert(!IsStrict && "Don't know how to expand for strict nodes.");
3675 
3676     // Otherwise, SETCC for the given comparison type must be completely
3677     // illegal; expand it into a SELECT_CC.
3678     // FIXME: This drops the mask/evl for VP_SETCC.
3679     EVT VT = Node->getValueType(0);
3680     EVT Tmp1VT = Tmp1.getValueType();
3681     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3682                        DAG.getBoolConstant(true, dl, VT, Tmp1VT),
3683                        DAG.getBoolConstant(false, dl, VT, Tmp1VT), Tmp3);
3684     Tmp1->setFlags(Node->getFlags());
3685     Results.push_back(Tmp1);
3686     break;
3687   }
3688   case ISD::SELECT_CC: {
3689     // TODO: need to add STRICT_SELECT_CC and STRICT_SELECT_CCS
3690     Tmp1 = Node->getOperand(0);   // LHS
3691     Tmp2 = Node->getOperand(1);   // RHS
3692     Tmp3 = Node->getOperand(2);   // True
3693     Tmp4 = Node->getOperand(3);   // False
3694     EVT VT = Node->getValueType(0);
3695     SDValue Chain;
3696     SDValue CC = Node->getOperand(4);
3697     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3698 
3699     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3700       // If the condition code is legal, then we need to expand this
3701       // node using SETCC and SELECT.
3702       EVT CmpVT = Tmp1.getValueType();
3703       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3704              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3705              "expanded.");
3706       EVT CCVT = getSetCCResultType(CmpVT);
3707       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC, Node->getFlags());
3708       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3709       break;
3710     }
3711 
3712     // SELECT_CC is legal, so the condition code must not be.
3713     bool Legalized = false;
3714     // Try to legalize by inverting the condition.  This is for targets that
3715     // might support an ordered version of a condition, but not the unordered
3716     // version (or vice versa).
3717     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp, Tmp1.getValueType());
3718     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3719       // Use the new condition code and swap true and false
3720       Legalized = true;
3721       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3722       Tmp1->setFlags(Node->getFlags());
3723     } else {
3724       // If The inverse is not legal, then try to swap the arguments using
3725       // the inverse condition code.
3726       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3727       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3728         // The swapped inverse condition is legal, so swap true and false,
3729         // lhs and rhs.
3730         Legalized = true;
3731         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3732         Tmp1->setFlags(Node->getFlags());
3733       }
3734     }
3735 
3736     if (!Legalized) {
3737       Legalized = TLI.LegalizeSetCCCondCode(
3738           DAG, getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC,
3739           /*Mask*/ SDValue(), /*EVL*/ SDValue(), NeedInvert, dl, Chain);
3740 
3741       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3742 
3743       // If we expanded the SETCC by inverting the condition code, then swap
3744       // the True/False operands to match.
3745       if (NeedInvert)
3746         std::swap(Tmp3, Tmp4);
3747 
3748       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3749       // condition code, create a new SELECT_CC node.
3750       if (CC.getNode()) {
3751         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3752                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3753       } else {
3754         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3755         CC = DAG.getCondCode(ISD::SETNE);
3756         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3757                            Tmp2, Tmp3, Tmp4, CC);
3758       }
3759       Tmp1->setFlags(Node->getFlags());
3760     }
3761     Results.push_back(Tmp1);
3762     break;
3763   }
3764   case ISD::BR_CC: {
3765     // TODO: need to add STRICT_BR_CC and STRICT_BR_CCS
3766     SDValue Chain;
3767     Tmp1 = Node->getOperand(0);              // Chain
3768     Tmp2 = Node->getOperand(2);              // LHS
3769     Tmp3 = Node->getOperand(3);              // RHS
3770     Tmp4 = Node->getOperand(1);              // CC
3771 
3772     bool Legalized = TLI.LegalizeSetCCCondCode(
3773         DAG, getSetCCResultType(Tmp2.getValueType()), Tmp2, Tmp3, Tmp4,
3774         /*Mask*/ SDValue(), /*EVL*/ SDValue(), NeedInvert, dl, Chain);
3775     (void)Legalized;
3776     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3777 
3778     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3779     // node.
3780     if (Tmp4.getNode()) {
3781       assert(!NeedInvert && "Don't know how to invert BR_CC!");
3782 
3783       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3784                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3785     } else {
3786       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3787       Tmp4 = DAG.getCondCode(NeedInvert ? ISD::SETEQ : ISD::SETNE);
3788       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3789                          Tmp2, Tmp3, Node->getOperand(4));
3790     }
3791     Results.push_back(Tmp1);
3792     break;
3793   }
3794   case ISD::BUILD_VECTOR:
3795     Results.push_back(ExpandBUILD_VECTOR(Node));
3796     break;
3797   case ISD::SPLAT_VECTOR:
3798     Results.push_back(ExpandSPLAT_VECTOR(Node));
3799     break;
3800   case ISD::SRA:
3801   case ISD::SRL:
3802   case ISD::SHL: {
3803     // Scalarize vector SRA/SRL/SHL.
3804     EVT VT = Node->getValueType(0);
3805     assert(VT.isVector() && "Unable to legalize non-vector shift");
3806     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3807     unsigned NumElem = VT.getVectorNumElements();
3808 
3809     SmallVector<SDValue, 8> Scalars;
3810     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3811       SDValue Ex =
3812           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3813                       Node->getOperand(0), DAG.getVectorIdxConstant(Idx, dl));
3814       SDValue Sh =
3815           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3816                       Node->getOperand(1), DAG.getVectorIdxConstant(Idx, dl));
3817       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3818                                     VT.getScalarType(), Ex, Sh));
3819     }
3820 
3821     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3822     Results.push_back(Result);
3823     break;
3824   }
3825   case ISD::VECREDUCE_FADD:
3826   case ISD::VECREDUCE_FMUL:
3827   case ISD::VECREDUCE_ADD:
3828   case ISD::VECREDUCE_MUL:
3829   case ISD::VECREDUCE_AND:
3830   case ISD::VECREDUCE_OR:
3831   case ISD::VECREDUCE_XOR:
3832   case ISD::VECREDUCE_SMAX:
3833   case ISD::VECREDUCE_SMIN:
3834   case ISD::VECREDUCE_UMAX:
3835   case ISD::VECREDUCE_UMIN:
3836   case ISD::VECREDUCE_FMAX:
3837   case ISD::VECREDUCE_FMIN:
3838     Results.push_back(TLI.expandVecReduce(Node, DAG));
3839     break;
3840   case ISD::GLOBAL_OFFSET_TABLE:
3841   case ISD::GlobalAddress:
3842   case ISD::GlobalTLSAddress:
3843   case ISD::ExternalSymbol:
3844   case ISD::ConstantPool:
3845   case ISD::JumpTable:
3846   case ISD::INTRINSIC_W_CHAIN:
3847   case ISD::INTRINSIC_WO_CHAIN:
3848   case ISD::INTRINSIC_VOID:
3849     // FIXME: Custom lowering for these operations shouldn't return null!
3850     // Return true so that we don't call ConvertNodeToLibcall which also won't
3851     // do anything.
3852     return true;
3853   }
3854 
3855   if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
3856     // FIXME: We were asked to expand a strict floating-point operation,
3857     // but there is currently no expansion implemented that would preserve
3858     // the "strict" properties.  For now, we just fall back to the non-strict
3859     // version if that is legal on the target.  The actual mutation of the
3860     // operation will happen in SelectionDAGISel::DoInstructionSelection.
3861     switch (Node->getOpcode()) {
3862     default:
3863       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3864                                          Node->getValueType(0))
3865           == TargetLowering::Legal)
3866         return true;
3867       break;
3868     case ISD::STRICT_FSUB: {
3869       if (TLI.getStrictFPOperationAction(
3870               ISD::STRICT_FSUB, Node->getValueType(0)) == TargetLowering::Legal)
3871         return true;
3872       if (TLI.getStrictFPOperationAction(
3873               ISD::STRICT_FADD, Node->getValueType(0)) != TargetLowering::Legal)
3874         break;
3875 
3876       EVT VT = Node->getValueType(0);
3877       const SDNodeFlags Flags = Node->getFlags();
3878       SDValue Neg = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(2), Flags);
3879       SDValue Fadd = DAG.getNode(ISD::STRICT_FADD, dl, Node->getVTList(),
3880                                  {Node->getOperand(0), Node->getOperand(1), Neg},
3881                          Flags);
3882 
3883       Results.push_back(Fadd);
3884       Results.push_back(Fadd.getValue(1));
3885       break;
3886     }
3887     case ISD::STRICT_SINT_TO_FP:
3888     case ISD::STRICT_UINT_TO_FP:
3889     case ISD::STRICT_LRINT:
3890     case ISD::STRICT_LLRINT:
3891     case ISD::STRICT_LROUND:
3892     case ISD::STRICT_LLROUND:
3893       // These are registered by the operand type instead of the value
3894       // type. Reflect that here.
3895       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3896                                          Node->getOperand(1).getValueType())
3897           == TargetLowering::Legal)
3898         return true;
3899       break;
3900     }
3901   }
3902 
3903   // Replace the original node with the legalized result.
3904   if (Results.empty()) {
3905     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3906     return false;
3907   }
3908 
3909   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3910   ReplaceNode(Node, Results.data());
3911   return true;
3912 }
3913 
3914 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3915   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3916   SmallVector<SDValue, 8> Results;
3917   SDLoc dl(Node);
3918   // FIXME: Check flags on the node to see if we can use a finite call.
3919   unsigned Opc = Node->getOpcode();
3920   switch (Opc) {
3921   case ISD::ATOMIC_FENCE: {
3922     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3923     // FIXME: handle "fence singlethread" more efficiently.
3924     TargetLowering::ArgListTy Args;
3925 
3926     TargetLowering::CallLoweringInfo CLI(DAG);
3927     CLI.setDebugLoc(dl)
3928         .setChain(Node->getOperand(0))
3929         .setLibCallee(
3930             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3931             DAG.getExternalSymbol("__sync_synchronize",
3932                                   TLI.getPointerTy(DAG.getDataLayout())),
3933             std::move(Args));
3934 
3935     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3936 
3937     Results.push_back(CallResult.second);
3938     break;
3939   }
3940   // By default, atomic intrinsics are marked Legal and lowered. Targets
3941   // which don't support them directly, however, may want libcalls, in which
3942   // case they mark them Expand, and we get here.
3943   case ISD::ATOMIC_SWAP:
3944   case ISD::ATOMIC_LOAD_ADD:
3945   case ISD::ATOMIC_LOAD_SUB:
3946   case ISD::ATOMIC_LOAD_AND:
3947   case ISD::ATOMIC_LOAD_CLR:
3948   case ISD::ATOMIC_LOAD_OR:
3949   case ISD::ATOMIC_LOAD_XOR:
3950   case ISD::ATOMIC_LOAD_NAND:
3951   case ISD::ATOMIC_LOAD_MIN:
3952   case ISD::ATOMIC_LOAD_MAX:
3953   case ISD::ATOMIC_LOAD_UMIN:
3954   case ISD::ATOMIC_LOAD_UMAX:
3955   case ISD::ATOMIC_CMP_SWAP: {
3956     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3957     AtomicOrdering Order = cast<AtomicSDNode>(Node)->getMergedOrdering();
3958     RTLIB::Libcall LC = RTLIB::getOUTLINE_ATOMIC(Opc, Order, VT);
3959     EVT RetVT = Node->getValueType(0);
3960     TargetLowering::MakeLibCallOptions CallOptions;
3961     SmallVector<SDValue, 4> Ops;
3962     if (TLI.getLibcallName(LC)) {
3963       // If outline atomic available, prepare its arguments and expand.
3964       Ops.append(Node->op_begin() + 2, Node->op_end());
3965       Ops.push_back(Node->getOperand(1));
3966 
3967     } else {
3968       LC = RTLIB::getSYNC(Opc, VT);
3969       assert(LC != RTLIB::UNKNOWN_LIBCALL &&
3970              "Unexpected atomic op or value type!");
3971       // Arguments for expansion to sync libcall
3972       Ops.append(Node->op_begin() + 1, Node->op_end());
3973     }
3974     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
3975                                                       Ops, CallOptions,
3976                                                       SDLoc(Node),
3977                                                       Node->getOperand(0));
3978     Results.push_back(Tmp.first);
3979     Results.push_back(Tmp.second);
3980     break;
3981   }
3982   case ISD::TRAP: {
3983     // If this operation is not supported, lower it to 'abort()' call
3984     TargetLowering::ArgListTy Args;
3985     TargetLowering::CallLoweringInfo CLI(DAG);
3986     CLI.setDebugLoc(dl)
3987         .setChain(Node->getOperand(0))
3988         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3989                       DAG.getExternalSymbol(
3990                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
3991                       std::move(Args));
3992     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3993 
3994     Results.push_back(CallResult.second);
3995     break;
3996   }
3997   case ISD::FMINNUM:
3998   case ISD::STRICT_FMINNUM:
3999     ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
4000                     RTLIB::FMIN_F80, RTLIB::FMIN_F128,
4001                     RTLIB::FMIN_PPCF128, Results);
4002     break;
4003   case ISD::FMAXNUM:
4004   case ISD::STRICT_FMAXNUM:
4005     ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
4006                     RTLIB::FMAX_F80, RTLIB::FMAX_F128,
4007                     RTLIB::FMAX_PPCF128, Results);
4008     break;
4009   case ISD::FSQRT:
4010   case ISD::STRICT_FSQRT:
4011     ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
4012                     RTLIB::SQRT_F80, RTLIB::SQRT_F128,
4013                     RTLIB::SQRT_PPCF128, Results);
4014     break;
4015   case ISD::FCBRT:
4016     ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
4017                     RTLIB::CBRT_F80, RTLIB::CBRT_F128,
4018                     RTLIB::CBRT_PPCF128, Results);
4019     break;
4020   case ISD::FSIN:
4021   case ISD::STRICT_FSIN:
4022     ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
4023                     RTLIB::SIN_F80, RTLIB::SIN_F128,
4024                     RTLIB::SIN_PPCF128, Results);
4025     break;
4026   case ISD::FCOS:
4027   case ISD::STRICT_FCOS:
4028     ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
4029                     RTLIB::COS_F80, RTLIB::COS_F128,
4030                     RTLIB::COS_PPCF128, Results);
4031     break;
4032   case ISD::FSINCOS:
4033     // Expand into sincos libcall.
4034     ExpandSinCosLibCall(Node, Results);
4035     break;
4036   case ISD::FLOG:
4037   case ISD::STRICT_FLOG:
4038     ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64, RTLIB::LOG_F80,
4039                     RTLIB::LOG_F128, RTLIB::LOG_PPCF128, Results);
4040     break;
4041   case ISD::FLOG2:
4042   case ISD::STRICT_FLOG2:
4043     ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64, RTLIB::LOG2_F80,
4044                     RTLIB::LOG2_F128, RTLIB::LOG2_PPCF128, Results);
4045     break;
4046   case ISD::FLOG10:
4047   case ISD::STRICT_FLOG10:
4048     ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64, RTLIB::LOG10_F80,
4049                     RTLIB::LOG10_F128, RTLIB::LOG10_PPCF128, Results);
4050     break;
4051   case ISD::FEXP:
4052   case ISD::STRICT_FEXP:
4053     ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64, RTLIB::EXP_F80,
4054                     RTLIB::EXP_F128, RTLIB::EXP_PPCF128, Results);
4055     break;
4056   case ISD::FEXP2:
4057   case ISD::STRICT_FEXP2:
4058     ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64, RTLIB::EXP2_F80,
4059                     RTLIB::EXP2_F128, RTLIB::EXP2_PPCF128, Results);
4060     break;
4061   case ISD::FTRUNC:
4062   case ISD::STRICT_FTRUNC:
4063     ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4064                     RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4065                     RTLIB::TRUNC_PPCF128, Results);
4066     break;
4067   case ISD::FFLOOR:
4068   case ISD::STRICT_FFLOOR:
4069     ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4070                     RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4071                     RTLIB::FLOOR_PPCF128, Results);
4072     break;
4073   case ISD::FCEIL:
4074   case ISD::STRICT_FCEIL:
4075     ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4076                     RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4077                     RTLIB::CEIL_PPCF128, Results);
4078     break;
4079   case ISD::FRINT:
4080   case ISD::STRICT_FRINT:
4081     ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4082                     RTLIB::RINT_F80, RTLIB::RINT_F128,
4083                     RTLIB::RINT_PPCF128, Results);
4084     break;
4085   case ISD::FNEARBYINT:
4086   case ISD::STRICT_FNEARBYINT:
4087     ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4088                     RTLIB::NEARBYINT_F64,
4089                     RTLIB::NEARBYINT_F80,
4090                     RTLIB::NEARBYINT_F128,
4091                     RTLIB::NEARBYINT_PPCF128, Results);
4092     break;
4093   case ISD::FROUND:
4094   case ISD::STRICT_FROUND:
4095     ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4096                     RTLIB::ROUND_F64,
4097                     RTLIB::ROUND_F80,
4098                     RTLIB::ROUND_F128,
4099                     RTLIB::ROUND_PPCF128, Results);
4100     break;
4101   case ISD::FROUNDEVEN:
4102   case ISD::STRICT_FROUNDEVEN:
4103     ExpandFPLibCall(Node, RTLIB::ROUNDEVEN_F32,
4104                     RTLIB::ROUNDEVEN_F64,
4105                     RTLIB::ROUNDEVEN_F80,
4106                     RTLIB::ROUNDEVEN_F128,
4107                     RTLIB::ROUNDEVEN_PPCF128, Results);
4108     break;
4109   case ISD::FPOWI:
4110   case ISD::STRICT_FPOWI: {
4111     RTLIB::Libcall LC = RTLIB::getPOWI(Node->getSimpleValueType(0));
4112     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected fpowi.");
4113     if (!TLI.getLibcallName(LC)) {
4114       // Some targets don't have a powi libcall; use pow instead.
4115       if (Node->isStrictFPOpcode()) {
4116         SDValue Exponent =
4117             DAG.getNode(ISD::STRICT_SINT_TO_FP, SDLoc(Node),
4118                         {Node->getValueType(0), Node->getValueType(1)},
4119                         {Node->getOperand(0), Node->getOperand(2)});
4120         SDValue FPOW =
4121             DAG.getNode(ISD::STRICT_FPOW, SDLoc(Node),
4122                         {Node->getValueType(0), Node->getValueType(1)},
4123                         {Exponent.getValue(1), Node->getOperand(1), Exponent});
4124         Results.push_back(FPOW);
4125         Results.push_back(FPOW.getValue(1));
4126       } else {
4127         SDValue Exponent =
4128             DAG.getNode(ISD::SINT_TO_FP, SDLoc(Node), Node->getValueType(0),
4129                         Node->getOperand(1));
4130         Results.push_back(DAG.getNode(ISD::FPOW, SDLoc(Node),
4131                                       Node->getValueType(0),
4132                                       Node->getOperand(0), Exponent));
4133       }
4134       break;
4135     }
4136     unsigned Offset = Node->isStrictFPOpcode() ? 1 : 0;
4137     bool ExponentHasSizeOfInt =
4138         DAG.getLibInfo().getIntSize() ==
4139         Node->getOperand(1 + Offset).getValueType().getSizeInBits();
4140     if (!ExponentHasSizeOfInt) {
4141       // If the exponent does not match with sizeof(int) a libcall to
4142       // RTLIB::POWI would use the wrong type for the argument.
4143       DAG.getContext()->emitError("POWI exponent does not match sizeof(int)");
4144       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
4145       break;
4146     }
4147     ExpandFPLibCall(Node, LC, Results);
4148     break;
4149   }
4150   case ISD::FPOW:
4151   case ISD::STRICT_FPOW:
4152     ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64, RTLIB::POW_F80,
4153                     RTLIB::POW_F128, RTLIB::POW_PPCF128, Results);
4154     break;
4155   case ISD::LROUND:
4156   case ISD::STRICT_LROUND:
4157     ExpandArgFPLibCall(Node, RTLIB::LROUND_F32,
4158                        RTLIB::LROUND_F64, RTLIB::LROUND_F80,
4159                        RTLIB::LROUND_F128,
4160                        RTLIB::LROUND_PPCF128, Results);
4161     break;
4162   case ISD::LLROUND:
4163   case ISD::STRICT_LLROUND:
4164     ExpandArgFPLibCall(Node, RTLIB::LLROUND_F32,
4165                        RTLIB::LLROUND_F64, RTLIB::LLROUND_F80,
4166                        RTLIB::LLROUND_F128,
4167                        RTLIB::LLROUND_PPCF128, Results);
4168     break;
4169   case ISD::LRINT:
4170   case ISD::STRICT_LRINT:
4171     ExpandArgFPLibCall(Node, RTLIB::LRINT_F32,
4172                        RTLIB::LRINT_F64, RTLIB::LRINT_F80,
4173                        RTLIB::LRINT_F128,
4174                        RTLIB::LRINT_PPCF128, Results);
4175     break;
4176   case ISD::LLRINT:
4177   case ISD::STRICT_LLRINT:
4178     ExpandArgFPLibCall(Node, RTLIB::LLRINT_F32,
4179                        RTLIB::LLRINT_F64, RTLIB::LLRINT_F80,
4180                        RTLIB::LLRINT_F128,
4181                        RTLIB::LLRINT_PPCF128, Results);
4182     break;
4183   case ISD::FDIV:
4184   case ISD::STRICT_FDIV:
4185     ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4186                     RTLIB::DIV_F80, RTLIB::DIV_F128,
4187                     RTLIB::DIV_PPCF128, Results);
4188     break;
4189   case ISD::FREM:
4190   case ISD::STRICT_FREM:
4191     ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4192                     RTLIB::REM_F80, RTLIB::REM_F128,
4193                     RTLIB::REM_PPCF128, Results);
4194     break;
4195   case ISD::FMA:
4196   case ISD::STRICT_FMA:
4197     ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4198                     RTLIB::FMA_F80, RTLIB::FMA_F128,
4199                     RTLIB::FMA_PPCF128, Results);
4200     break;
4201   case ISD::FADD:
4202   case ISD::STRICT_FADD:
4203     ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4204                     RTLIB::ADD_F80, RTLIB::ADD_F128,
4205                     RTLIB::ADD_PPCF128, Results);
4206     break;
4207   case ISD::FMUL:
4208   case ISD::STRICT_FMUL:
4209     ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4210                     RTLIB::MUL_F80, RTLIB::MUL_F128,
4211                     RTLIB::MUL_PPCF128, Results);
4212     break;
4213   case ISD::FP16_TO_FP:
4214     if (Node->getValueType(0) == MVT::f32) {
4215       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4216     }
4217     break;
4218   case ISD::STRICT_FP16_TO_FP: {
4219     if (Node->getValueType(0) == MVT::f32) {
4220       TargetLowering::MakeLibCallOptions CallOptions;
4221       std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(
4222           DAG, RTLIB::FPEXT_F16_F32, MVT::f32, Node->getOperand(1), CallOptions,
4223           SDLoc(Node), Node->getOperand(0));
4224       Results.push_back(Tmp.first);
4225       Results.push_back(Tmp.second);
4226     }
4227     break;
4228   }
4229   case ISD::FP_TO_FP16: {
4230     RTLIB::Libcall LC =
4231         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4232     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4233     Results.push_back(ExpandLibCall(LC, Node, false));
4234     break;
4235   }
4236   case ISD::FP_TO_BF16: {
4237     RTLIB::Libcall LC =
4238         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::bf16);
4239     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_bf16");
4240     Results.push_back(ExpandLibCall(LC, Node, false));
4241     break;
4242   }
4243   case ISD::STRICT_SINT_TO_FP:
4244   case ISD::STRICT_UINT_TO_FP:
4245   case ISD::SINT_TO_FP:
4246   case ISD::UINT_TO_FP: {
4247     // TODO - Common the code with DAGTypeLegalizer::SoftenFloatRes_XINT_TO_FP
4248     bool IsStrict = Node->isStrictFPOpcode();
4249     bool Signed = Node->getOpcode() == ISD::SINT_TO_FP ||
4250                   Node->getOpcode() == ISD::STRICT_SINT_TO_FP;
4251     EVT SVT = Node->getOperand(IsStrict ? 1 : 0).getValueType();
4252     EVT RVT = Node->getValueType(0);
4253     EVT NVT = EVT();
4254     SDLoc dl(Node);
4255 
4256     // Even if the input is legal, no libcall may exactly match, eg. we don't
4257     // have i1 -> fp conversions. So, it needs to be promoted to a larger type,
4258     // eg: i13 -> fp. Then, look for an appropriate libcall.
4259     RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
4260     for (unsigned t = MVT::FIRST_INTEGER_VALUETYPE;
4261          t <= MVT::LAST_INTEGER_VALUETYPE && LC == RTLIB::UNKNOWN_LIBCALL;
4262          ++t) {
4263       NVT = (MVT::SimpleValueType)t;
4264       // The source needs to big enough to hold the operand.
4265       if (NVT.bitsGE(SVT))
4266         LC = Signed ? RTLIB::getSINTTOFP(NVT, RVT)
4267                     : RTLIB::getUINTTOFP(NVT, RVT);
4268     }
4269     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4270 
4271     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
4272     // Sign/zero extend the argument if the libcall takes a larger type.
4273     SDValue Op = DAG.getNode(Signed ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND, dl,
4274                              NVT, Node->getOperand(IsStrict ? 1 : 0));
4275     TargetLowering::MakeLibCallOptions CallOptions;
4276     CallOptions.setSExt(Signed);
4277     std::pair<SDValue, SDValue> Tmp =
4278         TLI.makeLibCall(DAG, LC, RVT, Op, CallOptions, dl, Chain);
4279     Results.push_back(Tmp.first);
4280     if (IsStrict)
4281       Results.push_back(Tmp.second);
4282     break;
4283   }
4284   case ISD::FP_TO_SINT:
4285   case ISD::FP_TO_UINT:
4286   case ISD::STRICT_FP_TO_SINT:
4287   case ISD::STRICT_FP_TO_UINT: {
4288     // TODO - Common the code with DAGTypeLegalizer::SoftenFloatOp_FP_TO_XINT.
4289     bool IsStrict = Node->isStrictFPOpcode();
4290     bool Signed = Node->getOpcode() == ISD::FP_TO_SINT ||
4291                   Node->getOpcode() == ISD::STRICT_FP_TO_SINT;
4292 
4293     SDValue Op = Node->getOperand(IsStrict ? 1 : 0);
4294     EVT SVT = Op.getValueType();
4295     EVT RVT = Node->getValueType(0);
4296     EVT NVT = EVT();
4297     SDLoc dl(Node);
4298 
4299     // Even if the result is legal, no libcall may exactly match, eg. we don't
4300     // have fp -> i1 conversions. So, it needs to be promoted to a larger type,
4301     // eg: fp -> i32. Then, look for an appropriate libcall.
4302     RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
4303     for (unsigned IntVT = MVT::FIRST_INTEGER_VALUETYPE;
4304          IntVT <= MVT::LAST_INTEGER_VALUETYPE && LC == RTLIB::UNKNOWN_LIBCALL;
4305          ++IntVT) {
4306       NVT = (MVT::SimpleValueType)IntVT;
4307       // The type needs to big enough to hold the result.
4308       if (NVT.bitsGE(RVT))
4309         LC = Signed ? RTLIB::getFPTOSINT(SVT, NVT)
4310                     : RTLIB::getFPTOUINT(SVT, NVT);
4311     }
4312     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4313 
4314     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
4315     TargetLowering::MakeLibCallOptions CallOptions;
4316     std::pair<SDValue, SDValue> Tmp =
4317         TLI.makeLibCall(DAG, LC, NVT, Op, CallOptions, dl, Chain);
4318 
4319     // Truncate the result if the libcall returns a larger type.
4320     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, RVT, Tmp.first));
4321     if (IsStrict)
4322       Results.push_back(Tmp.second);
4323     break;
4324   }
4325 
4326   case ISD::FP_ROUND:
4327   case ISD::STRICT_FP_ROUND: {
4328     // X = FP_ROUND(Y, TRUNC)
4329     // TRUNC is a flag, which is always an integer that is zero or one.
4330     // If TRUNC is 0, this is a normal rounding, if it is 1, this FP_ROUND
4331     // is known to not change the value of Y.
4332     // We can only expand it into libcall if the TRUNC is 0.
4333     bool IsStrict = Node->isStrictFPOpcode();
4334     SDValue Op = Node->getOperand(IsStrict ? 1 : 0);
4335     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
4336     EVT VT = Node->getValueType(0);
4337     assert(cast<ConstantSDNode>(Node->getOperand(IsStrict ? 2 : 1))->isZero() &&
4338            "Unable to expand as libcall if it is not normal rounding");
4339 
4340     RTLIB::Libcall LC = RTLIB::getFPROUND(Op.getValueType(), VT);
4341     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4342 
4343     TargetLowering::MakeLibCallOptions CallOptions;
4344     std::pair<SDValue, SDValue> Tmp =
4345         TLI.makeLibCall(DAG, LC, VT, Op, CallOptions, SDLoc(Node), Chain);
4346     Results.push_back(Tmp.first);
4347     if (IsStrict)
4348       Results.push_back(Tmp.second);
4349     break;
4350   }
4351   case ISD::FP_EXTEND: {
4352     Results.push_back(
4353         ExpandLibCall(RTLIB::getFPEXT(Node->getOperand(0).getValueType(),
4354                                       Node->getValueType(0)),
4355                       Node, false));
4356     break;
4357   }
4358   case ISD::STRICT_FP_EXTEND:
4359   case ISD::STRICT_FP_TO_FP16: {
4360     RTLIB::Libcall LC =
4361         Node->getOpcode() == ISD::STRICT_FP_TO_FP16
4362             ? RTLIB::getFPROUND(Node->getOperand(1).getValueType(), MVT::f16)
4363             : RTLIB::getFPEXT(Node->getOperand(1).getValueType(),
4364                               Node->getValueType(0));
4365     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to legalize as libcall");
4366 
4367     TargetLowering::MakeLibCallOptions CallOptions;
4368     std::pair<SDValue, SDValue> Tmp =
4369         TLI.makeLibCall(DAG, LC, Node->getValueType(0), Node->getOperand(1),
4370                         CallOptions, SDLoc(Node), Node->getOperand(0));
4371     Results.push_back(Tmp.first);
4372     Results.push_back(Tmp.second);
4373     break;
4374   }
4375   case ISD::FSUB:
4376   case ISD::STRICT_FSUB:
4377     ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4378                     RTLIB::SUB_F80, RTLIB::SUB_F128,
4379                     RTLIB::SUB_PPCF128, Results);
4380     break;
4381   case ISD::SREM:
4382     Results.push_back(ExpandIntLibCall(
4383         Node, true, RTLIB::SREM_I8, RTLIB::SREM_I16, RTLIB::SREM_I32,
4384         RTLIB::SREM_I64, RTLIB::SREM_I128, RTLIB::SREM_IEXT));
4385     break;
4386   case ISD::UREM:
4387     Results.push_back(ExpandIntLibCall(
4388         Node, false, RTLIB::UREM_I8, RTLIB::UREM_I16, RTLIB::UREM_I32,
4389         RTLIB::UREM_I64, RTLIB::UREM_I128, RTLIB::UREM_IEXT));
4390     break;
4391   case ISD::SDIV:
4392     Results.push_back(ExpandIntLibCall(
4393         Node, true, RTLIB::SDIV_I8, RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4394         RTLIB::SDIV_I64, RTLIB::SDIV_I128, RTLIB::SDIV_IEXT));
4395     break;
4396   case ISD::UDIV:
4397     Results.push_back(ExpandIntLibCall(
4398         Node, false, RTLIB::UDIV_I8, RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4399         RTLIB::UDIV_I64, RTLIB::UDIV_I128, RTLIB::UDIV_IEXT));
4400     break;
4401   case ISD::SDIVREM:
4402   case ISD::UDIVREM:
4403     // Expand into divrem libcall
4404     ExpandDivRemLibCall(Node, Results);
4405     break;
4406   case ISD::MUL:
4407     Results.push_back(ExpandIntLibCall(
4408         Node, false, RTLIB::MUL_I8, RTLIB::MUL_I16, RTLIB::MUL_I32,
4409         RTLIB::MUL_I64, RTLIB::MUL_I128, RTLIB::MUL_IEXT));
4410     break;
4411   case ISD::CTLZ_ZERO_UNDEF:
4412     switch (Node->getSimpleValueType(0).SimpleTy) {
4413     default:
4414       llvm_unreachable("LibCall explicitly requested, but not available");
4415     case MVT::i32:
4416       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4417       break;
4418     case MVT::i64:
4419       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4420       break;
4421     case MVT::i128:
4422       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4423       break;
4424     }
4425     break;
4426   }
4427 
4428   // Replace the original node with the legalized result.
4429   if (!Results.empty()) {
4430     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4431     ReplaceNode(Node, Results.data());
4432   } else
4433     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4434 }
4435 
4436 // Determine the vector type to use in place of an original scalar element when
4437 // promoting equally sized vectors.
4438 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4439                                         MVT EltVT, MVT NewEltVT) {
4440   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4441   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4442   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4443   return MidVT;
4444 }
4445 
4446 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4447   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4448   SmallVector<SDValue, 8> Results;
4449   MVT OVT = Node->getSimpleValueType(0);
4450   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4451       Node->getOpcode() == ISD::SINT_TO_FP ||
4452       Node->getOpcode() == ISD::SETCC ||
4453       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4454       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4455     OVT = Node->getOperand(0).getSimpleValueType();
4456   }
4457   if (Node->getOpcode() == ISD::STRICT_UINT_TO_FP ||
4458       Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
4459       Node->getOpcode() == ISD::STRICT_FSETCC ||
4460       Node->getOpcode() == ISD::STRICT_FSETCCS)
4461     OVT = Node->getOperand(1).getSimpleValueType();
4462   if (Node->getOpcode() == ISD::BR_CC ||
4463       Node->getOpcode() == ISD::SELECT_CC)
4464     OVT = Node->getOperand(2).getSimpleValueType();
4465   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4466   SDLoc dl(Node);
4467   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
4468   switch (Node->getOpcode()) {
4469   case ISD::CTTZ:
4470   case ISD::CTTZ_ZERO_UNDEF:
4471   case ISD::CTLZ:
4472   case ISD::CTLZ_ZERO_UNDEF:
4473   case ISD::CTPOP:
4474     // Zero extend the argument unless its cttz, then use any_extend.
4475     if (Node->getOpcode() == ISD::CTTZ ||
4476         Node->getOpcode() == ISD::CTTZ_ZERO_UNDEF)
4477       Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4478     else
4479       Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4480 
4481     if (Node->getOpcode() == ISD::CTTZ) {
4482       // The count is the same in the promoted type except if the original
4483       // value was zero.  This can be handled by setting the bit just off
4484       // the top of the original type.
4485       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4486                                         OVT.getSizeInBits());
4487       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4488                          DAG.getConstant(TopBit, dl, NVT));
4489     }
4490     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4491     // already the correct result.
4492     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4493     if (Node->getOpcode() == ISD::CTLZ ||
4494         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4495       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4496       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4497                           DAG.getConstant(NVT.getSizeInBits() -
4498                                           OVT.getSizeInBits(), dl, NVT));
4499     }
4500     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4501     break;
4502   case ISD::BITREVERSE:
4503   case ISD::BSWAP: {
4504     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4505     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4506     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4507     Tmp1 = DAG.getNode(
4508         ISD::SRL, dl, NVT, Tmp1,
4509         DAG.getConstant(DiffBits, dl,
4510                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4511 
4512     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4513     break;
4514   }
4515   case ISD::FP_TO_UINT:
4516   case ISD::STRICT_FP_TO_UINT:
4517   case ISD::FP_TO_SINT:
4518   case ISD::STRICT_FP_TO_SINT:
4519     PromoteLegalFP_TO_INT(Node, dl, Results);
4520     break;
4521   case ISD::FP_TO_UINT_SAT:
4522   case ISD::FP_TO_SINT_SAT:
4523     Results.push_back(PromoteLegalFP_TO_INT_SAT(Node, dl));
4524     break;
4525   case ISD::UINT_TO_FP:
4526   case ISD::STRICT_UINT_TO_FP:
4527   case ISD::SINT_TO_FP:
4528   case ISD::STRICT_SINT_TO_FP:
4529     PromoteLegalINT_TO_FP(Node, dl, Results);
4530     break;
4531   case ISD::VAARG: {
4532     SDValue Chain = Node->getOperand(0); // Get the chain.
4533     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4534 
4535     unsigned TruncOp;
4536     if (OVT.isVector()) {
4537       TruncOp = ISD::BITCAST;
4538     } else {
4539       assert(OVT.isInteger()
4540         && "VAARG promotion is supported only for vectors or integer types");
4541       TruncOp = ISD::TRUNCATE;
4542     }
4543 
4544     // Perform the larger operation, then convert back
4545     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4546              Node->getConstantOperandVal(3));
4547     Chain = Tmp1.getValue(1);
4548 
4549     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4550 
4551     // Modified the chain result - switch anything that used the old chain to
4552     // use the new one.
4553     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4554     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4555     if (UpdatedNodes) {
4556       UpdatedNodes->insert(Tmp2.getNode());
4557       UpdatedNodes->insert(Chain.getNode());
4558     }
4559     ReplacedNode(Node);
4560     break;
4561   }
4562   case ISD::MUL:
4563   case ISD::SDIV:
4564   case ISD::SREM:
4565   case ISD::UDIV:
4566   case ISD::UREM:
4567   case ISD::AND:
4568   case ISD::OR:
4569   case ISD::XOR: {
4570     unsigned ExtOp, TruncOp;
4571     if (OVT.isVector()) {
4572       ExtOp   = ISD::BITCAST;
4573       TruncOp = ISD::BITCAST;
4574     } else {
4575       assert(OVT.isInteger() && "Cannot promote logic operation");
4576 
4577       switch (Node->getOpcode()) {
4578       default:
4579         ExtOp = ISD::ANY_EXTEND;
4580         break;
4581       case ISD::SDIV:
4582       case ISD::SREM:
4583         ExtOp = ISD::SIGN_EXTEND;
4584         break;
4585       case ISD::UDIV:
4586       case ISD::UREM:
4587         ExtOp = ISD::ZERO_EXTEND;
4588         break;
4589       }
4590       TruncOp = ISD::TRUNCATE;
4591     }
4592     // Promote each of the values to the new type.
4593     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4594     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4595     // Perform the larger operation, then convert back
4596     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4597     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4598     break;
4599   }
4600   case ISD::UMUL_LOHI:
4601   case ISD::SMUL_LOHI: {
4602     // Promote to a multiply in a wider integer type.
4603     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4604                                                          : ISD::SIGN_EXTEND;
4605     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4606     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4607     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4608 
4609     auto &DL = DAG.getDataLayout();
4610     unsigned OriginalSize = OVT.getScalarSizeInBits();
4611     Tmp2 = DAG.getNode(
4612         ISD::SRL, dl, NVT, Tmp1,
4613         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4614     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4615     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4616     break;
4617   }
4618   case ISD::SELECT: {
4619     unsigned ExtOp, TruncOp;
4620     if (Node->getValueType(0).isVector() ||
4621         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4622       ExtOp   = ISD::BITCAST;
4623       TruncOp = ISD::BITCAST;
4624     } else if (Node->getValueType(0).isInteger()) {
4625       ExtOp   = ISD::ANY_EXTEND;
4626       TruncOp = ISD::TRUNCATE;
4627     } else {
4628       ExtOp   = ISD::FP_EXTEND;
4629       TruncOp = ISD::FP_ROUND;
4630     }
4631     Tmp1 = Node->getOperand(0);
4632     // Promote each of the values to the new type.
4633     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4634     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4635     // Perform the larger operation, then round down.
4636     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4637     Tmp1->setFlags(Node->getFlags());
4638     if (TruncOp != ISD::FP_ROUND)
4639       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4640     else
4641       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4642                          DAG.getIntPtrConstant(0, dl));
4643     Results.push_back(Tmp1);
4644     break;
4645   }
4646   case ISD::VECTOR_SHUFFLE: {
4647     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4648 
4649     // Cast the two input vectors.
4650     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4651     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4652 
4653     // Convert the shuffle mask to the right # elements.
4654     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4655     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4656     Results.push_back(Tmp1);
4657     break;
4658   }
4659   case ISD::VECTOR_SPLICE: {
4660     Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4661     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(1));
4662     Tmp3 = DAG.getNode(ISD::VECTOR_SPLICE, dl, NVT, Tmp1, Tmp2,
4663                        Node->getOperand(2));
4664     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp3));
4665     break;
4666   }
4667   case ISD::SELECT_CC: {
4668     SDValue Cond = Node->getOperand(4);
4669     ISD::CondCode CCCode = cast<CondCodeSDNode>(Cond)->get();
4670     // Type of the comparison operands.
4671     MVT CVT = Node->getSimpleValueType(0);
4672     assert(CVT == OVT && "not handled");
4673 
4674     unsigned ExtOp = ISD::FP_EXTEND;
4675     if (NVT.isInteger()) {
4676       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4677     }
4678 
4679     // Promote the comparison operands, if needed.
4680     if (TLI.isCondCodeLegal(CCCode, CVT)) {
4681       Tmp1 = Node->getOperand(0);
4682       Tmp2 = Node->getOperand(1);
4683     } else {
4684       Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4685       Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4686     }
4687     // Cast the true/false operands.
4688     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4689     Tmp4 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4690 
4691     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, NVT, {Tmp1, Tmp2, Tmp3, Tmp4, Cond},
4692                        Node->getFlags());
4693 
4694     // Cast the result back to the original type.
4695     if (ExtOp != ISD::FP_EXTEND)
4696       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1);
4697     else
4698       Tmp1 = DAG.getNode(ISD::FP_ROUND, dl, OVT, Tmp1,
4699                          DAG.getIntPtrConstant(0, dl));
4700 
4701     Results.push_back(Tmp1);
4702     break;
4703   }
4704   case ISD::SETCC:
4705   case ISD::STRICT_FSETCC:
4706   case ISD::STRICT_FSETCCS: {
4707     unsigned ExtOp = ISD::FP_EXTEND;
4708     if (NVT.isInteger()) {
4709       ISD::CondCode CCCode = cast<CondCodeSDNode>(Node->getOperand(2))->get();
4710       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4711     }
4712     if (Node->isStrictFPOpcode()) {
4713       SDValue InChain = Node->getOperand(0);
4714       std::tie(Tmp1, std::ignore) =
4715           DAG.getStrictFPExtendOrRound(Node->getOperand(1), InChain, dl, NVT);
4716       std::tie(Tmp2, std::ignore) =
4717           DAG.getStrictFPExtendOrRound(Node->getOperand(2), InChain, dl, NVT);
4718       SmallVector<SDValue, 2> TmpChains = {Tmp1.getValue(1), Tmp2.getValue(1)};
4719       SDValue OutChain = DAG.getTokenFactor(dl, TmpChains);
4720       SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
4721       Results.push_back(DAG.getNode(Node->getOpcode(), dl, VTs,
4722                                     {OutChain, Tmp1, Tmp2, Node->getOperand(3)},
4723                                     Node->getFlags()));
4724       Results.push_back(Results.back().getValue(1));
4725       break;
4726     }
4727     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4728     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4729     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0), Tmp1,
4730                                   Tmp2, Node->getOperand(2), Node->getFlags()));
4731     break;
4732   }
4733   case ISD::BR_CC: {
4734     unsigned ExtOp = ISD::FP_EXTEND;
4735     if (NVT.isInteger()) {
4736       ISD::CondCode CCCode =
4737         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4738       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4739     }
4740     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4741     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4742     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4743                                   Node->getOperand(0), Node->getOperand(1),
4744                                   Tmp1, Tmp2, Node->getOperand(4)));
4745     break;
4746   }
4747   case ISD::FADD:
4748   case ISD::FSUB:
4749   case ISD::FMUL:
4750   case ISD::FDIV:
4751   case ISD::FREM:
4752   case ISD::FMINNUM:
4753   case ISD::FMAXNUM:
4754   case ISD::FPOW:
4755     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4756     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4757     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4758                        Node->getFlags());
4759     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4760                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4761     break;
4762   case ISD::STRICT_FADD:
4763   case ISD::STRICT_FSUB:
4764   case ISD::STRICT_FMUL:
4765   case ISD::STRICT_FDIV:
4766   case ISD::STRICT_FMINNUM:
4767   case ISD::STRICT_FMAXNUM:
4768   case ISD::STRICT_FREM:
4769   case ISD::STRICT_FPOW:
4770     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4771                        {Node->getOperand(0), Node->getOperand(1)});
4772     Tmp2 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4773                        {Node->getOperand(0), Node->getOperand(2)});
4774     Tmp3 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Tmp1.getValue(1),
4775                        Tmp2.getValue(1));
4776     Tmp1 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4777                        {Tmp3, Tmp1, Tmp2});
4778     Tmp1 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4779                        {Tmp1.getValue(1), Tmp1, DAG.getIntPtrConstant(0, dl)});
4780     Results.push_back(Tmp1);
4781     Results.push_back(Tmp1.getValue(1));
4782     break;
4783   case ISD::FMA:
4784     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4785     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4786     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4787     Results.push_back(
4788         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4789                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4790                     DAG.getIntPtrConstant(0, dl)));
4791     break;
4792   case ISD::STRICT_FMA:
4793     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4794                        {Node->getOperand(0), Node->getOperand(1)});
4795     Tmp2 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4796                        {Node->getOperand(0), Node->getOperand(2)});
4797     Tmp3 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4798                        {Node->getOperand(0), Node->getOperand(3)});
4799     Tmp4 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Tmp1.getValue(1),
4800                        Tmp2.getValue(1), Tmp3.getValue(1));
4801     Tmp4 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4802                        {Tmp4, Tmp1, Tmp2, Tmp3});
4803     Tmp4 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4804                        {Tmp4.getValue(1), Tmp4, DAG.getIntPtrConstant(0, dl)});
4805     Results.push_back(Tmp4);
4806     Results.push_back(Tmp4.getValue(1));
4807     break;
4808   case ISD::FCOPYSIGN:
4809   case ISD::FPOWI: {
4810     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4811     Tmp2 = Node->getOperand(1);
4812     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4813 
4814     // fcopysign doesn't change anything but the sign bit, so
4815     //   (fp_round (fcopysign (fpext a), b))
4816     // is as precise as
4817     //   (fp_round (fpext a))
4818     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4819     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4820     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4821                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4822     break;
4823   }
4824   case ISD::STRICT_FPOWI:
4825     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4826                        {Node->getOperand(0), Node->getOperand(1)});
4827     Tmp2 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4828                        {Tmp1.getValue(1), Tmp1, Node->getOperand(2)});
4829     Tmp3 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4830                        {Tmp2.getValue(1), Tmp2, DAG.getIntPtrConstant(0, dl)});
4831     Results.push_back(Tmp3);
4832     Results.push_back(Tmp3.getValue(1));
4833     break;
4834   case ISD::FFLOOR:
4835   case ISD::FCEIL:
4836   case ISD::FRINT:
4837   case ISD::FNEARBYINT:
4838   case ISD::FROUND:
4839   case ISD::FROUNDEVEN:
4840   case ISD::FTRUNC:
4841   case ISD::FNEG:
4842   case ISD::FSQRT:
4843   case ISD::FSIN:
4844   case ISD::FCOS:
4845   case ISD::FLOG:
4846   case ISD::FLOG2:
4847   case ISD::FLOG10:
4848   case ISD::FABS:
4849   case ISD::FEXP:
4850   case ISD::FEXP2:
4851     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4852     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4853     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4854                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4855     break;
4856   case ISD::STRICT_FFLOOR:
4857   case ISD::STRICT_FCEIL:
4858   case ISD::STRICT_FRINT:
4859   case ISD::STRICT_FNEARBYINT:
4860   case ISD::STRICT_FROUND:
4861   case ISD::STRICT_FROUNDEVEN:
4862   case ISD::STRICT_FTRUNC:
4863   case ISD::STRICT_FSQRT:
4864   case ISD::STRICT_FSIN:
4865   case ISD::STRICT_FCOS:
4866   case ISD::STRICT_FLOG:
4867   case ISD::STRICT_FLOG2:
4868   case ISD::STRICT_FLOG10:
4869   case ISD::STRICT_FEXP:
4870   case ISD::STRICT_FEXP2:
4871     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4872                        {Node->getOperand(0), Node->getOperand(1)});
4873     Tmp2 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4874                        {Tmp1.getValue(1), Tmp1});
4875     Tmp3 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4876                        {Tmp2.getValue(1), Tmp2, DAG.getIntPtrConstant(0, dl)});
4877     Results.push_back(Tmp3);
4878     Results.push_back(Tmp3.getValue(1));
4879     break;
4880   case ISD::BUILD_VECTOR: {
4881     MVT EltVT = OVT.getVectorElementType();
4882     MVT NewEltVT = NVT.getVectorElementType();
4883 
4884     // Handle bitcasts to a different vector type with the same total bit size
4885     //
4886     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4887     //  =>
4888     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4889 
4890     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4891            "Invalid promote type for build_vector");
4892     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4893 
4894     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4895 
4896     SmallVector<SDValue, 8> NewOps;
4897     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4898       SDValue Op = Node->getOperand(I);
4899       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4900     }
4901 
4902     SDLoc SL(Node);
4903     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4904     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4905     Results.push_back(CvtVec);
4906     break;
4907   }
4908   case ISD::EXTRACT_VECTOR_ELT: {
4909     MVT EltVT = OVT.getVectorElementType();
4910     MVT NewEltVT = NVT.getVectorElementType();
4911 
4912     // Handle bitcasts to a different vector type with the same total bit size.
4913     //
4914     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4915     //  =>
4916     //  v4i32:castx = bitcast x:v2i64
4917     //
4918     // i64 = bitcast
4919     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4920     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4921     //
4922 
4923     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4924            "Invalid promote type for extract_vector_elt");
4925     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4926 
4927     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4928     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4929 
4930     SDValue Idx = Node->getOperand(1);
4931     EVT IdxVT = Idx.getValueType();
4932     SDLoc SL(Node);
4933     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4934     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4935 
4936     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4937 
4938     SmallVector<SDValue, 8> NewOps;
4939     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4940       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4941       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4942 
4943       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4944                                 CastVec, TmpIdx);
4945       NewOps.push_back(Elt);
4946     }
4947 
4948     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4949     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4950     break;
4951   }
4952   case ISD::INSERT_VECTOR_ELT: {
4953     MVT EltVT = OVT.getVectorElementType();
4954     MVT NewEltVT = NVT.getVectorElementType();
4955 
4956     // Handle bitcasts to a different vector type with the same total bit size
4957     //
4958     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4959     //  =>
4960     //  v4i32:castx = bitcast x:v2i64
4961     //  v2i32:casty = bitcast y:i64
4962     //
4963     // v2i64 = bitcast
4964     //   (v4i32 insert_vector_elt
4965     //       (v4i32 insert_vector_elt v4i32:castx,
4966     //                                (extract_vector_elt casty, 0), 2 * z),
4967     //        (extract_vector_elt casty, 1), (2 * z + 1))
4968 
4969     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4970            "Invalid promote type for insert_vector_elt");
4971     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4972 
4973     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4974     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4975 
4976     SDValue Val = Node->getOperand(1);
4977     SDValue Idx = Node->getOperand(2);
4978     EVT IdxVT = Idx.getValueType();
4979     SDLoc SL(Node);
4980 
4981     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4982     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4983 
4984     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4985     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4986 
4987     SDValue NewVec = CastVec;
4988     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4989       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4990       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4991 
4992       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4993                                 CastVal, IdxOffset);
4994 
4995       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4996                            NewVec, Elt, InEltIdx);
4997     }
4998 
4999     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
5000     break;
5001   }
5002   case ISD::SCALAR_TO_VECTOR: {
5003     MVT EltVT = OVT.getVectorElementType();
5004     MVT NewEltVT = NVT.getVectorElementType();
5005 
5006     // Handle bitcasts to different vector type with the same total bit size.
5007     //
5008     // e.g. v2i64 = scalar_to_vector x:i64
5009     //   =>
5010     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
5011     //
5012 
5013     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
5014     SDValue Val = Node->getOperand(0);
5015     SDLoc SL(Node);
5016 
5017     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
5018     SDValue Undef = DAG.getUNDEF(MidVT);
5019 
5020     SmallVector<SDValue, 8> NewElts;
5021     NewElts.push_back(CastVal);
5022     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
5023       NewElts.push_back(Undef);
5024 
5025     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
5026     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
5027     Results.push_back(CvtVec);
5028     break;
5029   }
5030   case ISD::ATOMIC_SWAP: {
5031     AtomicSDNode *AM = cast<AtomicSDNode>(Node);
5032     SDLoc SL(Node);
5033     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NVT, AM->getVal());
5034     assert(NVT.getSizeInBits() == OVT.getSizeInBits() &&
5035            "unexpected promotion type");
5036     assert(AM->getMemoryVT().getSizeInBits() == NVT.getSizeInBits() &&
5037            "unexpected atomic_swap with illegal type");
5038 
5039     SDValue NewAtomic
5040       = DAG.getAtomic(ISD::ATOMIC_SWAP, SL, NVT,
5041                       DAG.getVTList(NVT, MVT::Other),
5042                       { AM->getChain(), AM->getBasePtr(), CastVal },
5043                       AM->getMemOperand());
5044     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewAtomic));
5045     Results.push_back(NewAtomic.getValue(1));
5046     break;
5047   }
5048   }
5049 
5050   // Replace the original node with the legalized result.
5051   if (!Results.empty()) {
5052     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
5053     ReplaceNode(Node, Results.data());
5054   } else
5055     LLVM_DEBUG(dbgs() << "Could not promote node\n");
5056 }
5057 
5058 /// This is the entry point for the file.
5059 void SelectionDAG::Legalize() {
5060   AssignTopologicalOrder();
5061 
5062   SmallPtrSet<SDNode *, 16> LegalizedNodes;
5063   // Use a delete listener to remove nodes which were deleted during
5064   // legalization from LegalizeNodes. This is needed to handle the situation
5065   // where a new node is allocated by the object pool to the same address of a
5066   // previously deleted node.
5067   DAGNodeDeletedListener DeleteListener(
5068       *this,
5069       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
5070 
5071   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
5072 
5073   // Visit all the nodes. We start in topological order, so that we see
5074   // nodes with their original operands intact. Legalization can produce
5075   // new nodes which may themselves need to be legalized. Iterate until all
5076   // nodes have been legalized.
5077   while (true) {
5078     bool AnyLegalized = false;
5079     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
5080       --NI;
5081 
5082       SDNode *N = &*NI;
5083       if (N->use_empty() && N != getRoot().getNode()) {
5084         ++NI;
5085         DeleteNode(N);
5086         continue;
5087       }
5088 
5089       if (LegalizedNodes.insert(N).second) {
5090         AnyLegalized = true;
5091         Legalizer.LegalizeOp(N);
5092 
5093         if (N->use_empty() && N != getRoot().getNode()) {
5094           ++NI;
5095           DeleteNode(N);
5096         }
5097       }
5098     }
5099     if (!AnyLegalized)
5100       break;
5101 
5102   }
5103 
5104   // Remove dead nodes now.
5105   RemoveDeadNodes();
5106 }
5107 
5108 bool SelectionDAG::LegalizeOp(SDNode *N,
5109                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
5110   SmallPtrSet<SDNode *, 16> LegalizedNodes;
5111   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
5112 
5113   // Directly insert the node in question, and legalize it. This will recurse
5114   // as needed through operands.
5115   LegalizedNodes.insert(N);
5116   Legalizer.LegalizeOp(N);
5117 
5118   return LegalizedNodes.count(N);
5119 }
5120