1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the SelectionDAG::Legalize method.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/APFloat.h"
14 #include "llvm/ADT/APInt.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/SetVector.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/SmallSet.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/Analysis/TargetLibraryInfo.h"
21 #include "llvm/CodeGen/ISDOpcodes.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/RuntimeLibcalls.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGNodes.h"
28 #include "llvm/CodeGen/TargetFrameLowering.h"
29 #include "llvm/CodeGen/TargetLowering.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/CodeGen/ValueTypes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/MachineValueType.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include <algorithm>
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
137                              bool &NeedInvert, const SDLoc &dl, SDValue &Chain,
138                              bool IsSignaling = false);
139 
140   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
141 
142   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
143                        RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
144                        RTLIB::Libcall Call_F128,
145                        RTLIB::Libcall Call_PPCF128,
146                        SmallVectorImpl<SDValue> &Results);
147   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
148                            RTLIB::Libcall Call_I8,
149                            RTLIB::Libcall Call_I16,
150                            RTLIB::Libcall Call_I32,
151                            RTLIB::Libcall Call_I64,
152                            RTLIB::Libcall Call_I128);
153   void ExpandArgFPLibCall(SDNode *Node,
154                           RTLIB::Libcall Call_F32, RTLIB::Libcall Call_F64,
155                           RTLIB::Libcall Call_F80, RTLIB::Libcall Call_F128,
156                           RTLIB::Libcall Call_PPCF128,
157                           SmallVectorImpl<SDValue> &Results);
158   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
159   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
160 
161   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
162                            const SDLoc &dl);
163   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
164                            const SDLoc &dl, SDValue ChainIn);
165   SDValue ExpandBUILD_VECTOR(SDNode *Node);
166   SDValue ExpandSPLAT_VECTOR(SDNode *Node);
167   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
168   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
169                                 SmallVectorImpl<SDValue> &Results);
170   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
171                          SDValue Value) const;
172   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
173                           SDValue NewIntValue) const;
174   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
175   SDValue ExpandFABS(SDNode *Node) const;
176   SDValue ExpandLegalINT_TO_FP(SDNode *Node, SDValue &Chain);
177   void PromoteLegalINT_TO_FP(SDNode *N, const SDLoc &dl,
178                              SmallVectorImpl<SDValue> &Results);
179   void PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
180                              SmallVectorImpl<SDValue> &Results);
181 
182   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
183   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
184 
185   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
186   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
187   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
188 
189   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
190   SDValue ExpandConstant(ConstantSDNode *CP);
191 
192   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
193   bool ExpandNode(SDNode *Node);
194   void ConvertNodeToLibcall(SDNode *Node);
195   void PromoteNode(SDNode *Node);
196 
197 public:
198   // Node replacement helpers
199 
200   void ReplacedNode(SDNode *N) {
201     LegalizedNodes.erase(N);
202     if (UpdatedNodes)
203       UpdatedNodes->insert(N);
204   }
205 
206   void ReplaceNode(SDNode *Old, SDNode *New) {
207     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
208                dbgs() << "     with:      "; New->dump(&DAG));
209 
210     assert(Old->getNumValues() == New->getNumValues() &&
211            "Replacing one node with another that produces a different number "
212            "of values!");
213     DAG.ReplaceAllUsesWith(Old, New);
214     if (UpdatedNodes)
215       UpdatedNodes->insert(New);
216     ReplacedNode(Old);
217   }
218 
219   void ReplaceNode(SDValue Old, SDValue New) {
220     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
221                dbgs() << "     with:      "; New->dump(&DAG));
222 
223     DAG.ReplaceAllUsesWith(Old, New);
224     if (UpdatedNodes)
225       UpdatedNodes->insert(New.getNode());
226     ReplacedNode(Old.getNode());
227   }
228 
229   void ReplaceNode(SDNode *Old, const SDValue *New) {
230     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
231 
232     DAG.ReplaceAllUsesWith(Old, New);
233     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
234       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
235                  New[i]->dump(&DAG));
236       if (UpdatedNodes)
237         UpdatedNodes->insert(New[i].getNode());
238     }
239     ReplacedNode(Old);
240   }
241 
242   void ReplaceNodeWithValue(SDValue Old, SDValue New) {
243     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
244                dbgs() << "     with:      "; New->dump(&DAG));
245 
246     DAG.ReplaceAllUsesOfValueWith(Old, New);
247     if (UpdatedNodes)
248       UpdatedNodes->insert(New.getNode());
249     ReplacedNode(Old.getNode());
250   }
251 };
252 
253 } // end anonymous namespace
254 
255 /// Return a vector shuffle operation which
256 /// performs the same shuffle in terms of order or result bytes, but on a type
257 /// whose vector element type is narrower than the original shuffle type.
258 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
259 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
260     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
261     ArrayRef<int> Mask) const {
262   unsigned NumMaskElts = VT.getVectorNumElements();
263   unsigned NumDestElts = NVT.getVectorNumElements();
264   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
265 
266   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
267 
268   if (NumEltsGrowth == 1)
269     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
270 
271   SmallVector<int, 8> NewMask;
272   for (unsigned i = 0; i != NumMaskElts; ++i) {
273     int Idx = Mask[i];
274     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
275       if (Idx < 0)
276         NewMask.push_back(-1);
277       else
278         NewMask.push_back(Idx * NumEltsGrowth + j);
279     }
280   }
281   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
282   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
283   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
284 }
285 
286 /// Expands the ConstantFP node to an integer constant or
287 /// a load from the constant pool.
288 SDValue
289 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
290   bool Extend = false;
291   SDLoc dl(CFP);
292 
293   // If a FP immediate is precise when represented as a float and if the
294   // target can do an extending load from float to double, we put it into
295   // the constant pool as a float, even if it's is statically typed as a
296   // double.  This shrinks FP constants and canonicalizes them for targets where
297   // an FP extending load is the same cost as a normal load (such as on the x87
298   // fp stack or PPC FP unit).
299   EVT VT = CFP->getValueType(0);
300   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
301   if (!UseCP) {
302     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
303     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
304                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
305   }
306 
307   APFloat APF = CFP->getValueAPF();
308   EVT OrigVT = VT;
309   EVT SVT = VT;
310 
311   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
312   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
313   if (!APF.isSignaling()) {
314     while (SVT != MVT::f32 && SVT != MVT::f16) {
315       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
316       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
317           // Only do this if the target has a native EXTLOAD instruction from
318           // smaller type.
319           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
320           TLI.ShouldShrinkFPConstant(OrigVT)) {
321         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
322         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
323         VT = SVT;
324         Extend = true;
325       }
326     }
327   }
328 
329   SDValue CPIdx =
330       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
331   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
332   if (Extend) {
333     SDValue Result = DAG.getExtLoad(
334         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
335         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
336         Alignment);
337     return Result;
338   }
339   SDValue Result = DAG.getLoad(
340       OrigVT, dl, DAG.getEntryNode(), CPIdx,
341       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
342   return Result;
343 }
344 
345 /// Expands the Constant node to a load from the constant pool.
346 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
347   SDLoc dl(CP);
348   EVT VT = CP->getValueType(0);
349   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
350                                       TLI.getPointerTy(DAG.getDataLayout()));
351   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
352   SDValue Result = DAG.getLoad(
353       VT, dl, DAG.getEntryNode(), CPIdx,
354       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
355   return Result;
356 }
357 
358 /// Some target cannot handle a variable insertion index for the
359 /// INSERT_VECTOR_ELT instruction.  In this case, it
360 /// is necessary to spill the vector being inserted into to memory, perform
361 /// the insert there, and then read the result back.
362 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
363                                                              SDValue Val,
364                                                              SDValue Idx,
365                                                              const SDLoc &dl) {
366   SDValue Tmp1 = Vec;
367   SDValue Tmp2 = Val;
368   SDValue Tmp3 = Idx;
369 
370   // If the target doesn't support this, we have to spill the input vector
371   // to a temporary stack slot, update the element, then reload it.  This is
372   // badness.  We could also load the value into a vector register (either
373   // with a "move to register" or "extload into register" instruction, then
374   // permute it into place, if the idx is a constant and if the idx is
375   // supported by the target.
376   EVT VT    = Tmp1.getValueType();
377   EVT EltVT = VT.getVectorElementType();
378   SDValue StackPtr = DAG.CreateStackTemporary(VT);
379 
380   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
381 
382   // Store the vector.
383   SDValue Ch = DAG.getStore(
384       DAG.getEntryNode(), dl, Tmp1, StackPtr,
385       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
386 
387   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
388 
389   // Store the scalar value.
390   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT);
391   // Load the updated vector.
392   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
393                                                DAG.getMachineFunction(), SPFI));
394 }
395 
396 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
397                                                       SDValue Idx,
398                                                       const SDLoc &dl) {
399   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
400     // SCALAR_TO_VECTOR requires that the type of the value being inserted
401     // match the element type of the vector being created, except for
402     // integers in which case the inserted value can be over width.
403     EVT EltVT = Vec.getValueType().getVectorElementType();
404     if (Val.getValueType() == EltVT ||
405         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
406       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
407                                   Vec.getValueType(), Val);
408 
409       unsigned NumElts = Vec.getValueType().getVectorNumElements();
410       // We generate a shuffle of InVec and ScVec, so the shuffle mask
411       // should be 0,1,2,3,4,5... with the appropriate element replaced with
412       // elt 0 of the RHS.
413       SmallVector<int, 8> ShufOps;
414       for (unsigned i = 0; i != NumElts; ++i)
415         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
416 
417       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
418     }
419   }
420   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
421 }
422 
423 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
424   if (!ISD::isNormalStore(ST))
425     return SDValue();
426 
427   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
428   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
429   // FIXME: We shouldn't do this for TargetConstantFP's.
430   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
431   // to phase ordering between legalized code and the dag combiner.  This
432   // probably means that we need to integrate dag combiner and legalizer
433   // together.
434   // We generally can't do this one for long doubles.
435   SDValue Chain = ST->getChain();
436   SDValue Ptr = ST->getBasePtr();
437   unsigned Alignment = ST->getAlignment();
438   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
439   AAMDNodes AAInfo = ST->getAAInfo();
440   SDLoc dl(ST);
441   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
442     if (CFP->getValueType(0) == MVT::f32 &&
443         TLI.isTypeLegal(MVT::i32)) {
444       SDValue Con = DAG.getConstant(CFP->getValueAPF().
445                                       bitcastToAPInt().zextOrTrunc(32),
446                                     SDLoc(CFP), MVT::i32);
447       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(), Alignment,
448                           MMOFlags, AAInfo);
449     }
450 
451     if (CFP->getValueType(0) == MVT::f64) {
452       // If this target supports 64-bit registers, do a single 64-bit store.
453       if (TLI.isTypeLegal(MVT::i64)) {
454         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
455                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
456         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
457                             Alignment, MMOFlags, AAInfo);
458       }
459 
460       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
461         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
462         // stores.  If the target supports neither 32- nor 64-bits, this
463         // xform is certainly not worth it.
464         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
465         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
466         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
467         if (DAG.getDataLayout().isBigEndian())
468           std::swap(Lo, Hi);
469 
470         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), Alignment,
471                           MMOFlags, AAInfo);
472         Ptr = DAG.getMemBasePlusOffset(Ptr, 4, dl);
473         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
474                           ST->getPointerInfo().getWithOffset(4),
475                           MinAlign(Alignment, 4U), MMOFlags, AAInfo);
476 
477         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
478       }
479     }
480   }
481   return SDValue(nullptr, 0);
482 }
483 
484 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
485   StoreSDNode *ST = cast<StoreSDNode>(Node);
486   SDValue Chain = ST->getChain();
487   SDValue Ptr = ST->getBasePtr();
488   SDLoc dl(Node);
489 
490   unsigned Alignment = ST->getAlignment();
491   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
492   AAMDNodes AAInfo = ST->getAAInfo();
493 
494   if (!ST->isTruncatingStore()) {
495     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
496     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
497       ReplaceNode(ST, OptStore);
498       return;
499     }
500 
501     SDValue Value = ST->getValue();
502     MVT VT = Value.getSimpleValueType();
503     switch (TLI.getOperationAction(ISD::STORE, VT)) {
504     default: llvm_unreachable("This action is not supported yet!");
505     case TargetLowering::Legal: {
506       // If this is an unaligned store and the target doesn't support it,
507       // expand it.
508       EVT MemVT = ST->getMemoryVT();
509       const DataLayout &DL = DAG.getDataLayout();
510       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
511                                               *ST->getMemOperand())) {
512         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
513         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
514         ReplaceNode(SDValue(ST, 0), Result);
515       } else
516         LLVM_DEBUG(dbgs() << "Legal store\n");
517       break;
518     }
519     case TargetLowering::Custom: {
520       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
521       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
522       if (Res && Res != SDValue(Node, 0))
523         ReplaceNode(SDValue(Node, 0), Res);
524       return;
525     }
526     case TargetLowering::Promote: {
527       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
528       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
529              "Can only promote stores to same size type");
530       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
531       SDValue Result =
532           DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
533                        Alignment, MMOFlags, AAInfo);
534       ReplaceNode(SDValue(Node, 0), Result);
535       break;
536     }
537     }
538     return;
539   }
540 
541   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
542   SDValue Value = ST->getValue();
543   EVT StVT = ST->getMemoryVT();
544   unsigned StWidth = StVT.getSizeInBits();
545   auto &DL = DAG.getDataLayout();
546 
547   if (StWidth != StVT.getStoreSizeInBits()) {
548     // Promote to a byte-sized store with upper bits zero if not
549     // storing an integral number of bytes.  For example, promote
550     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
551     EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
552                                 StVT.getStoreSizeInBits());
553     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
554     SDValue Result =
555         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
556                           Alignment, MMOFlags, AAInfo);
557     ReplaceNode(SDValue(Node, 0), Result);
558   } else if (StWidth & (StWidth - 1)) {
559     // If not storing a power-of-2 number of bits, expand as two stores.
560     assert(!StVT.isVector() && "Unsupported truncstore!");
561     unsigned LogStWidth = Log2_32(StWidth);
562     assert(LogStWidth < 32);
563     unsigned RoundWidth = 1 << LogStWidth;
564     assert(RoundWidth < StWidth);
565     unsigned ExtraWidth = StWidth - RoundWidth;
566     assert(ExtraWidth < RoundWidth);
567     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
568            "Store size not an integral number of bytes!");
569     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
570     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
571     SDValue Lo, Hi;
572     unsigned IncrementSize;
573 
574     if (DL.isLittleEndian()) {
575       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
576       // Store the bottom RoundWidth bits.
577       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
578                              RoundVT, Alignment, MMOFlags, AAInfo);
579 
580       // Store the remaining ExtraWidth bits.
581       IncrementSize = RoundWidth / 8;
582       Ptr = DAG.getMemBasePlusOffset(Ptr, IncrementSize, dl);
583       Hi = DAG.getNode(
584           ISD::SRL, dl, Value.getValueType(), Value,
585           DAG.getConstant(RoundWidth, dl,
586                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
587       Hi = DAG.getTruncStore(
588           Chain, dl, Hi, Ptr,
589           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
590           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
591     } else {
592       // Big endian - avoid unaligned stores.
593       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
594       // Store the top RoundWidth bits.
595       Hi = DAG.getNode(
596           ISD::SRL, dl, Value.getValueType(), Value,
597           DAG.getConstant(ExtraWidth, dl,
598                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
599       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
600                              RoundVT, Alignment, MMOFlags, AAInfo);
601 
602       // Store the remaining ExtraWidth bits.
603       IncrementSize = RoundWidth / 8;
604       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
605                         DAG.getConstant(IncrementSize, dl,
606                                         Ptr.getValueType()));
607       Lo = DAG.getTruncStore(
608           Chain, dl, Value, Ptr,
609           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
610           MinAlign(Alignment, IncrementSize), 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                               Alignment, 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 = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
654                                    StVT, Alignment, MMOFlags, AAInfo);
655       }
656 
657       ReplaceNode(SDValue(Node, 0), Result);
658       break;
659     }
660   }
661 }
662 
663 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
664   LoadSDNode *LD = cast<LoadSDNode>(Node);
665   SDValue Chain = LD->getChain();  // The chain.
666   SDValue Ptr = LD->getBasePtr();  // The base pointer.
667   SDValue Value;                   // The value returned by the load op.
668   SDLoc dl(Node);
669 
670   ISD::LoadExtType ExtType = LD->getExtensionType();
671   if (ExtType == ISD::NON_EXTLOAD) {
672     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
673     MVT VT = Node->getSimpleValueType(0);
674     SDValue RVal = SDValue(Node, 0);
675     SDValue RChain = SDValue(Node, 1);
676 
677     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
678     default: llvm_unreachable("This action is not supported yet!");
679     case TargetLowering::Legal: {
680       EVT MemVT = LD->getMemoryVT();
681       const DataLayout &DL = DAG.getDataLayout();
682       // If this is an unaligned load and the target doesn't support it,
683       // expand it.
684       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
685                                               *LD->getMemOperand())) {
686         std::tie(RVal, RChain) = TLI.expandUnalignedLoad(LD, DAG);
687       }
688       break;
689     }
690     case TargetLowering::Custom:
691       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
692         RVal = Res;
693         RChain = Res.getValue(1);
694       }
695       break;
696 
697     case TargetLowering::Promote: {
698       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
699       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
700              "Can only promote loads to same size type");
701 
702       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
703       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
704       RChain = Res.getValue(1);
705       break;
706     }
707     }
708     if (RChain.getNode() != Node) {
709       assert(RVal.getNode() != Node && "Load must be completely replaced");
710       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
711       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
712       if (UpdatedNodes) {
713         UpdatedNodes->insert(RVal.getNode());
714         UpdatedNodes->insert(RChain.getNode());
715       }
716       ReplacedNode(Node);
717     }
718     return;
719   }
720 
721   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
722   EVT SrcVT = LD->getMemoryVT();
723   unsigned SrcWidth = SrcVT.getSizeInBits();
724   unsigned Alignment = LD->getAlignment();
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 =
752         DAG.getExtLoad(NewExtType, dl, Node->getValueType(0), Chain, Ptr,
753                        LD->getPointerInfo(), NVT, Alignment, 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 (SrcWidth & (SrcWidth - 1)) {
771     // If not loading a power-of-2 number of bits, expand as two loads.
772     assert(!SrcVT.isVector() && "Unsupported extload!");
773     unsigned LogSrcWidth = Log2_32(SrcWidth);
774     assert(LogSrcWidth < 32);
775     unsigned RoundWidth = 1 << LogSrcWidth;
776     assert(RoundWidth < SrcWidth);
777     unsigned ExtraWidth = SrcWidth - RoundWidth;
778     assert(ExtraWidth < RoundWidth);
779     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
780            "Load size not an integral number of bytes!");
781     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
782     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
783     SDValue Lo, Hi, Ch;
784     unsigned IncrementSize;
785     auto &DL = DAG.getDataLayout();
786 
787     if (DL.isLittleEndian()) {
788       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
789       // Load the bottom RoundWidth bits.
790       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
791                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
792                           AAInfo);
793 
794       // Load the remaining ExtraWidth bits.
795       IncrementSize = RoundWidth / 8;
796       Ptr = DAG.getMemBasePlusOffset(Ptr, IncrementSize, dl);
797       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
798                           LD->getPointerInfo().getWithOffset(IncrementSize),
799                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
800                           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, Alignment, MMOFlags,
821                           AAInfo);
822 
823       // Load the remaining ExtraWidth bits.
824       IncrementSize = RoundWidth / 8;
825       Ptr = DAG.getMemBasePlusOffset(Ptr, IncrementSize, dl);
826       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
827                           LD->getPointerInfo().getWithOffset(IncrementSize),
828                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
829                           AAInfo);
830 
831       // Build a factor node to remember that this load is independent of
832       // the other one.
833       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
834                        Hi.getValue(1));
835 
836       // Move the top bits to the right place.
837       Hi = DAG.getNode(
838           ISD::SHL, dl, Hi.getValueType(), Hi,
839           DAG.getConstant(ExtraWidth, dl,
840                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
841 
842       // Join the hi and lo parts.
843       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
844     }
845 
846     Chain = Ch;
847   } else {
848     bool isCustom = false;
849     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
850                                  SrcVT.getSimpleVT())) {
851     default: llvm_unreachable("This action is not supported yet!");
852     case TargetLowering::Custom:
853       isCustom = true;
854       LLVM_FALLTHROUGH;
855     case TargetLowering::Legal:
856       Value = SDValue(Node, 0);
857       Chain = SDValue(Node, 1);
858 
859       if (isCustom) {
860         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
861           Value = Res;
862           Chain = Res.getValue(1);
863         }
864       } else {
865         // If this is an unaligned load and the target doesn't support it,
866         // expand it.
867         EVT MemVT = LD->getMemoryVT();
868         const DataLayout &DL = DAG.getDataLayout();
869         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT,
870                                     *LD->getMemOperand())) {
871           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
872         }
873       }
874       break;
875 
876     case TargetLowering::Expand: {
877       EVT DestVT = Node->getValueType(0);
878       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
879         // If the source type is not legal, see if there is a legal extload to
880         // an intermediate type that we can then extend further.
881         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
882         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
883             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
884           // If we are loading a legal type, this is a non-extload followed by a
885           // full extend.
886           ISD::LoadExtType MidExtType =
887               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
888 
889           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
890                                         SrcVT, LD->getMemOperand());
891           unsigned ExtendOp =
892               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
893           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
894           Chain = Load.getValue(1);
895           break;
896         }
897 
898         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
899         // normal undefined upper bits behavior to allow using an in-reg extend
900         // with the illegal FP type, so load as an integer and do the
901         // from-integer conversion.
902         if (SrcVT.getScalarType() == MVT::f16) {
903           EVT ISrcVT = SrcVT.changeTypeToInteger();
904           EVT IDestVT = DestVT.changeTypeToInteger();
905           EVT ILoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
906 
907           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, ILoadVT, Chain,
908                                           Ptr, ISrcVT, LD->getMemOperand());
909           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
910           Chain = Result.getValue(1);
911           break;
912         }
913       }
914 
915       assert(!SrcVT.isVector() &&
916              "Vector Loads are handled in LegalizeVectorOps");
917 
918       // FIXME: This does not work for vectors on most targets.  Sign-
919       // and zero-extend operations are currently folded into extending
920       // loads, whether they are legal or not, and then we end up here
921       // without any support for legalizing them.
922       assert(ExtType != ISD::EXTLOAD &&
923              "EXTLOAD should always be supported!");
924       // Turn the unsupported load into an EXTLOAD followed by an
925       // explicit zero/sign extend inreg.
926       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
927                                       Node->getValueType(0),
928                                       Chain, Ptr, SrcVT,
929                                       LD->getMemOperand());
930       SDValue ValRes;
931       if (ExtType == ISD::SEXTLOAD)
932         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
933                              Result.getValueType(),
934                              Result, DAG.getValueType(SrcVT));
935       else
936         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
937       Value = ValRes;
938       Chain = Result.getValue(1);
939       break;
940     }
941     }
942   }
943 
944   // Since loads produce two values, make sure to remember that we legalized
945   // both of them.
946   if (Chain.getNode() != Node) {
947     assert(Value.getNode() != Node && "Load must be completely replaced");
948     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
949     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
950     if (UpdatedNodes) {
951       UpdatedNodes->insert(Value.getNode());
952       UpdatedNodes->insert(Chain.getNode());
953     }
954     ReplacedNode(Node);
955   }
956 }
957 
958 /// Return a legal replacement for the given operation, with all legal operands.
959 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
960   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
961 
962   // Allow illegal target nodes and illegal registers.
963   if (Node->getOpcode() == ISD::TargetConstant ||
964       Node->getOpcode() == ISD::Register)
965     return;
966 
967 #ifndef NDEBUG
968   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
969     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
970              TargetLowering::TypeLegal &&
971            "Unexpected illegal type!");
972 
973   for (const SDValue &Op : Node->op_values())
974     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
975               TargetLowering::TypeLegal ||
976             Op.getOpcode() == ISD::TargetConstant ||
977             Op.getOpcode() == ISD::Register) &&
978             "Unexpected illegal type!");
979 #endif
980 
981   // Figure out the correct action; the way to query this varies by opcode
982   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
983   bool SimpleFinishLegalizing = true;
984   switch (Node->getOpcode()) {
985   case ISD::INTRINSIC_W_CHAIN:
986   case ISD::INTRINSIC_WO_CHAIN:
987   case ISD::INTRINSIC_VOID:
988   case ISD::STACKSAVE:
989     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
990     break;
991   case ISD::GET_DYNAMIC_AREA_OFFSET:
992     Action = TLI.getOperationAction(Node->getOpcode(),
993                                     Node->getValueType(0));
994     break;
995   case ISD::VAARG:
996     Action = TLI.getOperationAction(Node->getOpcode(),
997                                     Node->getValueType(0));
998     if (Action != TargetLowering::Promote)
999       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
1000     break;
1001   case ISD::FP_TO_FP16:
1002   case ISD::SINT_TO_FP:
1003   case ISD::UINT_TO_FP:
1004   case ISD::EXTRACT_VECTOR_ELT:
1005   case ISD::LROUND:
1006   case ISD::LLROUND:
1007   case ISD::LRINT:
1008   case ISD::LLRINT:
1009     Action = TLI.getOperationAction(Node->getOpcode(),
1010                                     Node->getOperand(0).getValueType());
1011     break;
1012   case ISD::STRICT_FP_TO_FP16:
1013   case ISD::STRICT_SINT_TO_FP:
1014   case ISD::STRICT_UINT_TO_FP:
1015   case ISD::STRICT_LRINT:
1016   case ISD::STRICT_LLRINT:
1017   case ISD::STRICT_LROUND:
1018   case ISD::STRICT_LLROUND:
1019     // These pseudo-ops are the same as the other STRICT_ ops except
1020     // they are registered with setOperationAction() using the input type
1021     // instead of the output type.
1022     Action = TLI.getOperationAction(Node->getOpcode(),
1023                                     Node->getOperand(1).getValueType());
1024     break;
1025   case ISD::SIGN_EXTEND_INREG: {
1026     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1027     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1028     break;
1029   }
1030   case ISD::ATOMIC_STORE:
1031     Action = TLI.getOperationAction(Node->getOpcode(),
1032                                     Node->getOperand(2).getValueType());
1033     break;
1034   case ISD::SELECT_CC:
1035   case ISD::STRICT_FSETCC:
1036   case ISD::STRICT_FSETCCS:
1037   case ISD::SETCC:
1038   case ISD::BR_CC: {
1039     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1040                          Node->getOpcode() == ISD::STRICT_FSETCC ? 3 :
1041                          Node->getOpcode() == ISD::STRICT_FSETCCS ? 3 :
1042                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1043     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 :
1044                               Node->getOpcode() == ISD::STRICT_FSETCC ? 1 :
1045                               Node->getOpcode() == ISD::STRICT_FSETCCS ? 1 : 0;
1046     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1047     ISD::CondCode CCCode =
1048         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1049     Action = TLI.getCondCodeAction(CCCode, OpVT);
1050     if (Action == TargetLowering::Legal) {
1051       if (Node->getOpcode() == ISD::SELECT_CC)
1052         Action = TLI.getOperationAction(Node->getOpcode(),
1053                                         Node->getValueType(0));
1054       else
1055         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1056     }
1057     break;
1058   }
1059   case ISD::LOAD:
1060   case ISD::STORE:
1061     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1062     // STORE expects the unlegalized operand in some cases.
1063     SimpleFinishLegalizing = false;
1064     break;
1065   case ISD::CALLSEQ_START:
1066   case ISD::CALLSEQ_END:
1067     // FIXME: This shouldn't be necessary.  These nodes have special properties
1068     // dealing with the recursive nature of legalization.  Removing this
1069     // special case should be done as part of making LegalizeDAG non-recursive.
1070     SimpleFinishLegalizing = false;
1071     break;
1072   case ISD::EXTRACT_ELEMENT:
1073   case ISD::FLT_ROUNDS_:
1074   case ISD::MERGE_VALUES:
1075   case ISD::EH_RETURN:
1076   case ISD::FRAME_TO_ARGS_OFFSET:
1077   case ISD::EH_DWARF_CFA:
1078   case ISD::EH_SJLJ_SETJMP:
1079   case ISD::EH_SJLJ_LONGJMP:
1080   case ISD::EH_SJLJ_SETUP_DISPATCH:
1081     // These operations lie about being legal: when they claim to be legal,
1082     // they should actually be expanded.
1083     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1084     if (Action == TargetLowering::Legal)
1085       Action = TargetLowering::Expand;
1086     break;
1087   case ISD::INIT_TRAMPOLINE:
1088   case ISD::ADJUST_TRAMPOLINE:
1089   case ISD::FRAMEADDR:
1090   case ISD::RETURNADDR:
1091   case ISD::ADDROFRETURNADDR:
1092   case ISD::SPONENTRY:
1093     // These operations lie about being legal: when they claim to be legal,
1094     // they should actually be custom-lowered.
1095     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1096     if (Action == TargetLowering::Legal)
1097       Action = TargetLowering::Custom;
1098     break;
1099   case ISD::READCYCLECOUNTER:
1100     // READCYCLECOUNTER returns an i64, even if type legalization might have
1101     // expanded that to several smaller types.
1102     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1103     break;
1104   case ISD::READ_REGISTER:
1105   case ISD::WRITE_REGISTER:
1106     // Named register is legal in the DAG, but blocked by register name
1107     // selection if not implemented by target (to chose the correct register)
1108     // They'll be converted to Copy(To/From)Reg.
1109     Action = TargetLowering::Legal;
1110     break;
1111   case ISD::DEBUGTRAP:
1112     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1113     if (Action == TargetLowering::Expand) {
1114       // replace ISD::DEBUGTRAP with ISD::TRAP
1115       SDValue NewVal;
1116       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1117                            Node->getOperand(0));
1118       ReplaceNode(Node, NewVal.getNode());
1119       LegalizeOp(NewVal.getNode());
1120       return;
1121     }
1122     break;
1123   case ISD::SADDSAT:
1124   case ISD::UADDSAT:
1125   case ISD::SSUBSAT:
1126   case ISD::USUBSAT: {
1127     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1128     break;
1129   }
1130   case ISD::SMULFIX:
1131   case ISD::SMULFIXSAT:
1132   case ISD::UMULFIX:
1133   case ISD::UMULFIXSAT:
1134   case ISD::SDIVFIX:
1135   case ISD::UDIVFIX: {
1136     unsigned Scale = Node->getConstantOperandVal(2);
1137     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1138                                               Node->getValueType(0), Scale);
1139     break;
1140   }
1141   case ISD::MSCATTER:
1142     Action = TLI.getOperationAction(Node->getOpcode(),
1143                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1144     break;
1145   case ISD::MSTORE:
1146     Action = TLI.getOperationAction(Node->getOpcode(),
1147                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1148     break;
1149   case ISD::VECREDUCE_FADD:
1150   case ISD::VECREDUCE_FMUL:
1151   case ISD::VECREDUCE_ADD:
1152   case ISD::VECREDUCE_MUL:
1153   case ISD::VECREDUCE_AND:
1154   case ISD::VECREDUCE_OR:
1155   case ISD::VECREDUCE_XOR:
1156   case ISD::VECREDUCE_SMAX:
1157   case ISD::VECREDUCE_SMIN:
1158   case ISD::VECREDUCE_UMAX:
1159   case ISD::VECREDUCE_UMIN:
1160   case ISD::VECREDUCE_FMAX:
1161   case ISD::VECREDUCE_FMIN:
1162     Action = TLI.getOperationAction(
1163         Node->getOpcode(), Node->getOperand(0).getValueType());
1164     break;
1165   default:
1166     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1167       Action = TargetLowering::Legal;
1168     } else {
1169       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1170     }
1171     break;
1172   }
1173 
1174   if (SimpleFinishLegalizing) {
1175     SDNode *NewNode = Node;
1176     switch (Node->getOpcode()) {
1177     default: break;
1178     case ISD::SHL:
1179     case ISD::SRL:
1180     case ISD::SRA:
1181     case ISD::ROTL:
1182     case ISD::ROTR: {
1183       // Legalizing shifts/rotates requires adjusting the shift amount
1184       // to the appropriate width.
1185       SDValue Op0 = Node->getOperand(0);
1186       SDValue Op1 = Node->getOperand(1);
1187       if (!Op1.getValueType().isVector()) {
1188         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1189         // The getShiftAmountOperand() may create a new operand node or
1190         // return the existing one. If new operand is created we need
1191         // to update the parent node.
1192         // Do not try to legalize SAO here! It will be automatically legalized
1193         // in the next round.
1194         if (SAO != Op1)
1195           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1196       }
1197     }
1198     break;
1199     case ISD::FSHL:
1200     case ISD::FSHR:
1201     case ISD::SRL_PARTS:
1202     case ISD::SRA_PARTS:
1203     case ISD::SHL_PARTS: {
1204       // Legalizing shifts/rotates requires adjusting the shift amount
1205       // to the appropriate width.
1206       SDValue Op0 = Node->getOperand(0);
1207       SDValue Op1 = Node->getOperand(1);
1208       SDValue Op2 = Node->getOperand(2);
1209       if (!Op2.getValueType().isVector()) {
1210         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1211         // The getShiftAmountOperand() may create a new operand node or
1212         // return the existing one. If new operand is created we need
1213         // to update the parent node.
1214         if (SAO != Op2)
1215           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1216       }
1217       break;
1218     }
1219     }
1220 
1221     if (NewNode != Node) {
1222       ReplaceNode(Node, NewNode);
1223       Node = NewNode;
1224     }
1225     switch (Action) {
1226     case TargetLowering::Legal:
1227       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1228       return;
1229     case TargetLowering::Custom:
1230       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1231       // FIXME: The handling for custom lowering with multiple results is
1232       // a complete mess.
1233       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1234         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1235           return;
1236 
1237         if (Node->getNumValues() == 1) {
1238           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1239           // We can just directly replace this node with the lowered value.
1240           ReplaceNode(SDValue(Node, 0), Res);
1241           return;
1242         }
1243 
1244         SmallVector<SDValue, 8> ResultVals;
1245         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1246           ResultVals.push_back(Res.getValue(i));
1247         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1248         ReplaceNode(Node, ResultVals.data());
1249         return;
1250       }
1251       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1252       LLVM_FALLTHROUGH;
1253     case TargetLowering::Expand:
1254       if (ExpandNode(Node))
1255         return;
1256       LLVM_FALLTHROUGH;
1257     case TargetLowering::LibCall:
1258       ConvertNodeToLibcall(Node);
1259       return;
1260     case TargetLowering::Promote:
1261       PromoteNode(Node);
1262       return;
1263     }
1264   }
1265 
1266   switch (Node->getOpcode()) {
1267   default:
1268 #ifndef NDEBUG
1269     dbgs() << "NODE: ";
1270     Node->dump( &DAG);
1271     dbgs() << "\n";
1272 #endif
1273     llvm_unreachable("Do not know how to legalize this operator!");
1274 
1275   case ISD::CALLSEQ_START:
1276   case ISD::CALLSEQ_END:
1277     break;
1278   case ISD::LOAD:
1279     return LegalizeLoadOps(Node);
1280   case ISD::STORE:
1281     return LegalizeStoreOps(Node);
1282   }
1283 }
1284 
1285 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1286   SDValue Vec = Op.getOperand(0);
1287   SDValue Idx = Op.getOperand(1);
1288   SDLoc dl(Op);
1289 
1290   // Before we generate a new store to a temporary stack slot, see if there is
1291   // already one that we can use. There often is because when we scalarize
1292   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1293   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1294   // the vector. If all are expanded here, we don't want one store per vector
1295   // element.
1296 
1297   // Caches for hasPredecessorHelper
1298   SmallPtrSet<const SDNode *, 32> Visited;
1299   SmallVector<const SDNode *, 16> Worklist;
1300   Visited.insert(Op.getNode());
1301   Worklist.push_back(Idx.getNode());
1302   SDValue StackPtr, Ch;
1303   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1304        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1305     SDNode *User = *UI;
1306     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1307       if (ST->isIndexed() || ST->isTruncatingStore() ||
1308           ST->getValue() != Vec)
1309         continue;
1310 
1311       // Make sure that nothing else could have stored into the destination of
1312       // this store.
1313       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1314         continue;
1315 
1316       // If the index is dependent on the store we will introduce a cycle when
1317       // creating the load (the load uses the index, and by replacing the chain
1318       // we will make the index dependent on the load). Also, the store might be
1319       // dependent on the extractelement and introduce a cycle when creating
1320       // the load.
1321       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1322           ST->hasPredecessor(Op.getNode()))
1323         continue;
1324 
1325       StackPtr = ST->getBasePtr();
1326       Ch = SDValue(ST, 0);
1327       break;
1328     }
1329   }
1330 
1331   EVT VecVT = Vec.getValueType();
1332 
1333   if (!Ch.getNode()) {
1334     // Store the value to a temporary stack slot, then LOAD the returned part.
1335     StackPtr = DAG.CreateStackTemporary(VecVT);
1336     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1337                       MachinePointerInfo());
1338   }
1339 
1340   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1341 
1342   SDValue NewLoad;
1343 
1344   if (Op.getValueType().isVector())
1345     NewLoad =
1346         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1347   else
1348     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1349                              MachinePointerInfo(),
1350                              VecVT.getVectorElementType());
1351 
1352   // Replace the chain going out of the store, by the one out of the load.
1353   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1354 
1355   // We introduced a cycle though, so update the loads operands, making sure
1356   // to use the original store's chain as an incoming chain.
1357   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1358                                           NewLoad->op_end());
1359   NewLoadOperands[0] = Ch;
1360   NewLoad =
1361       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1362   return NewLoad;
1363 }
1364 
1365 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1366   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1367 
1368   SDValue Vec  = Op.getOperand(0);
1369   SDValue Part = Op.getOperand(1);
1370   SDValue Idx  = Op.getOperand(2);
1371   SDLoc dl(Op);
1372 
1373   // Store the value to a temporary stack slot, then LOAD the returned part.
1374   EVT VecVT = Vec.getValueType();
1375   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1376   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1377   MachinePointerInfo PtrInfo =
1378       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1379 
1380   // First store the whole vector.
1381   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1382 
1383   // Then store the inserted part.
1384   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1385 
1386   // Store the subvector.
1387   Ch = DAG.getStore(Ch, dl, Part, SubStackPtr, MachinePointerInfo());
1388 
1389   // Finally, load the updated vector.
1390   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1391 }
1392 
1393 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1394   // We can't handle this case efficiently.  Allocate a sufficiently
1395   // aligned object on the stack, store each element into it, then load
1396   // the result as a vector.
1397   // Create the stack frame object.
1398   EVT VT = Node->getValueType(0);
1399   EVT EltVT = VT.getVectorElementType();
1400   SDLoc dl(Node);
1401   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1402   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1403   MachinePointerInfo PtrInfo =
1404       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1405 
1406   // Emit a store of each element to the stack slot.
1407   SmallVector<SDValue, 8> Stores;
1408   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
1409   assert(TypeByteSize > 0 && "Vector element type too small for stack store!");
1410   // Store (in the right endianness) the elements to memory.
1411   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1412     // Ignore undef elements.
1413     if (Node->getOperand(i).isUndef()) continue;
1414 
1415     unsigned Offset = TypeByteSize*i;
1416 
1417     SDValue Idx = DAG.getConstant(Offset, dl, FIPtr.getValueType());
1418     Idx = DAG.getMemBasePlusOffset(FIPtr, Idx, dl);
1419 
1420     // If the destination vector element type is narrower than the source
1421     // element type, only store the bits necessary.
1422     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
1423       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1424                                          Node->getOperand(i), Idx,
1425                                          PtrInfo.getWithOffset(Offset), EltVT));
1426     } else
1427       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1428                                     Idx, PtrInfo.getWithOffset(Offset)));
1429   }
1430 
1431   SDValue StoreChain;
1432   if (!Stores.empty())    // Not all undef elements?
1433     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1434   else
1435     StoreChain = DAG.getEntryNode();
1436 
1437   // Result is a load from the stack slot.
1438   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1439 }
1440 
1441 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1442 /// containing the sign bit if the target has no integer value capable of
1443 /// holding all bits of the floating-point value.
1444 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1445                                              const SDLoc &DL,
1446                                              SDValue Value) const {
1447   EVT FloatVT = Value.getValueType();
1448   unsigned NumBits = FloatVT.getSizeInBits();
1449   State.FloatVT = FloatVT;
1450   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1451   // Convert to an integer of the same size.
1452   if (TLI.isTypeLegal(IVT)) {
1453     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1454     State.SignMask = APInt::getSignMask(NumBits);
1455     State.SignBit = NumBits - 1;
1456     return;
1457   }
1458 
1459   auto &DataLayout = DAG.getDataLayout();
1460   // Store the float to memory, then load the sign part out as an integer.
1461   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1462   // First create a temporary that is aligned for both the load and store.
1463   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1464   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1465   // Then store the float to it.
1466   State.FloatPtr = StackPtr;
1467   MachineFunction &MF = DAG.getMachineFunction();
1468   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1469   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1470                              State.FloatPointerInfo);
1471 
1472   SDValue IntPtr;
1473   if (DataLayout.isBigEndian()) {
1474     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1475     // Load out a legal integer with the same sign bit as the float.
1476     IntPtr = StackPtr;
1477     State.IntPointerInfo = State.FloatPointerInfo;
1478   } else {
1479     // Advance the pointer so that the loaded byte will contain the sign bit.
1480     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1481     IntPtr = DAG.getMemBasePlusOffset(StackPtr, ByteOffset, DL);
1482     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1483                                                              ByteOffset);
1484   }
1485 
1486   State.IntPtr = IntPtr;
1487   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1488                                   State.IntPointerInfo, MVT::i8);
1489   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1490   State.SignBit = 7;
1491 }
1492 
1493 /// Replace the integer value produced by getSignAsIntValue() with a new value
1494 /// and cast the result back to a floating-point type.
1495 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1496                                               const SDLoc &DL,
1497                                               SDValue NewIntValue) const {
1498   if (!State.Chain)
1499     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1500 
1501   // Override the part containing the sign bit in the value stored on the stack.
1502   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1503                                     State.IntPointerInfo, MVT::i8);
1504   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1505                      State.FloatPointerInfo);
1506 }
1507 
1508 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1509   SDLoc DL(Node);
1510   SDValue Mag = Node->getOperand(0);
1511   SDValue Sign = Node->getOperand(1);
1512 
1513   // Get sign bit into an integer value.
1514   FloatSignAsInt SignAsInt;
1515   getSignAsIntValue(SignAsInt, DL, Sign);
1516 
1517   EVT IntVT = SignAsInt.IntValue.getValueType();
1518   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1519   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1520                                 SignMask);
1521 
1522   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1523   EVT FloatVT = Mag.getValueType();
1524   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1525       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1526     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1527     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1528     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1529                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1530     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1531   }
1532 
1533   // Transform Mag value to integer, and clear the sign bit.
1534   FloatSignAsInt MagAsInt;
1535   getSignAsIntValue(MagAsInt, DL, Mag);
1536   EVT MagVT = MagAsInt.IntValue.getValueType();
1537   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1538   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1539                                     ClearSignMask);
1540 
1541   // Get the signbit at the right position for MagAsInt.
1542   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1543   EVT ShiftVT = IntVT;
1544   if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1545     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1546     ShiftVT = MagVT;
1547   }
1548   if (ShiftAmount > 0) {
1549     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1550     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1551   } else if (ShiftAmount < 0) {
1552     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1553     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1554   }
1555   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1556     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1557   }
1558 
1559   // Store the part with the modified sign and convert back to float.
1560   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1561   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1562 }
1563 
1564 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1565   SDLoc DL(Node);
1566   SDValue Value = Node->getOperand(0);
1567 
1568   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1569   EVT FloatVT = Value.getValueType();
1570   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1571     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1572     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1573   }
1574 
1575   // Transform value to integer, clear the sign bit and transform back.
1576   FloatSignAsInt ValueAsInt;
1577   getSignAsIntValue(ValueAsInt, DL, Value);
1578   EVT IntVT = ValueAsInt.IntValue.getValueType();
1579   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1580   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1581                                     ClearSignMask);
1582   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1583 }
1584 
1585 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1586                                            SmallVectorImpl<SDValue> &Results) {
1587   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1588   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1589           " not tell us which reg is the stack pointer!");
1590   SDLoc dl(Node);
1591   EVT VT = Node->getValueType(0);
1592   SDValue Tmp1 = SDValue(Node, 0);
1593   SDValue Tmp2 = SDValue(Node, 1);
1594   SDValue Tmp3 = Node->getOperand(2);
1595   SDValue Chain = Tmp1.getOperand(0);
1596 
1597   // Chain the dynamic stack allocation so that it doesn't modify the stack
1598   // pointer when other instructions are using the stack.
1599   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1600 
1601   SDValue Size  = Tmp2.getOperand(1);
1602   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1603   Chain = SP.getValue(1);
1604   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
1605   unsigned StackAlign =
1606       DAG.getSubtarget().getFrameLowering()->getStackAlignment();
1607   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
1608   if (Align > StackAlign)
1609     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1610                        DAG.getConstant(-(uint64_t)Align, dl, VT));
1611   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1612 
1613   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1614                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1615 
1616   Results.push_back(Tmp1);
1617   Results.push_back(Tmp2);
1618 }
1619 
1620 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1621 /// target.
1622 ///
1623 /// If the SETCC has been legalized using AND / OR, then the legalized node
1624 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1625 /// will be set to false.
1626 ///
1627 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1628 /// then the values of LHS and RHS will be swapped, CC will be set to the
1629 /// new condition, and NeedInvert will be set to false.
1630 ///
1631 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1632 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1633 /// will be set to true. The caller must invert the result of the SETCC with
1634 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1635 /// of a true/false result.
1636 ///
1637 /// \returns true if the SetCC has been legalized, false if it hasn't.
1638 bool SelectionDAGLegalize::LegalizeSetCCCondCode(
1639     EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC, bool &NeedInvert,
1640     const SDLoc &dl, SDValue &Chain, bool IsSignaling) {
1641   MVT OpVT = LHS.getSimpleValueType();
1642   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1643   NeedInvert = false;
1644   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1645   default: llvm_unreachable("Unknown condition code action!");
1646   case TargetLowering::Legal:
1647     // Nothing to do.
1648     break;
1649   case TargetLowering::Expand: {
1650     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1651     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1652       std::swap(LHS, RHS);
1653       CC = DAG.getCondCode(InvCC);
1654       return true;
1655     }
1656     // Swapping operands didn't work. Try inverting the condition.
1657     bool NeedSwap = false;
1658     InvCC = getSetCCInverse(CCCode, OpVT);
1659     if (!TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1660       // If inverting the condition is not enough, try swapping operands
1661       // on top of it.
1662       InvCC = ISD::getSetCCSwappedOperands(InvCC);
1663       NeedSwap = true;
1664     }
1665     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1666       CC = DAG.getCondCode(InvCC);
1667       NeedInvert = true;
1668       if (NeedSwap)
1669         std::swap(LHS, RHS);
1670       return true;
1671     }
1672 
1673     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1674     unsigned Opc = 0;
1675     switch (CCCode) {
1676     default: llvm_unreachable("Don't know how to expand this condition!");
1677     case ISD::SETO:
1678         assert(TLI.isCondCodeLegal(ISD::SETOEQ, OpVT)
1679             && "If SETO is expanded, SETOEQ must be legal!");
1680         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1681     case ISD::SETUO:
1682         assert(TLI.isCondCodeLegal(ISD::SETUNE, OpVT)
1683             && "If SETUO is expanded, SETUNE must be legal!");
1684         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1685     case ISD::SETOEQ:
1686     case ISD::SETOGT:
1687     case ISD::SETOGE:
1688     case ISD::SETOLT:
1689     case ISD::SETOLE:
1690     case ISD::SETONE:
1691     case ISD::SETUEQ:
1692     case ISD::SETUNE:
1693     case ISD::SETUGT:
1694     case ISD::SETUGE:
1695     case ISD::SETULT:
1696     case ISD::SETULE:
1697         // If we are floating point, assign and break, otherwise fall through.
1698         if (!OpVT.isInteger()) {
1699           // We can use the 4th bit to tell if we are the unordered
1700           // or ordered version of the opcode.
1701           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1702           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1703           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1704           break;
1705         }
1706         // Fallthrough if we are unsigned integer.
1707         LLVM_FALLTHROUGH;
1708     case ISD::SETLE:
1709     case ISD::SETGT:
1710     case ISD::SETGE:
1711     case ISD::SETLT:
1712     case ISD::SETNE:
1713     case ISD::SETEQ:
1714       // If all combinations of inverting the condition and swapping operands
1715       // didn't work then we have no means to expand the condition.
1716       llvm_unreachable("Don't know how to expand this condition!");
1717     }
1718 
1719     SDValue SetCC1, SetCC2;
1720     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1721       // If we aren't the ordered or unorder operation,
1722       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1723       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1, Chain, IsSignaling);
1724       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2, Chain, IsSignaling);
1725     } else {
1726       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1727       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1, Chain, IsSignaling);
1728       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2, Chain, IsSignaling);
1729     }
1730     if (Chain)
1731       Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, SetCC1.getValue(1),
1732                           SetCC2.getValue(1));
1733     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1734     RHS = SDValue();
1735     CC  = SDValue();
1736     return true;
1737   }
1738   }
1739   return false;
1740 }
1741 
1742 /// Emit a store/load combination to the stack.  This stores
1743 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1744 /// a load from the stack slot to DestVT, extending it if needed.
1745 /// The resultant code need not be legal.
1746 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1747                                                EVT DestVT, const SDLoc &dl) {
1748   return EmitStackConvert(SrcOp, SlotVT, DestVT, dl, DAG.getEntryNode());
1749 }
1750 
1751 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1752                                                EVT DestVT, const SDLoc &dl,
1753                                                SDValue Chain) {
1754   // Create the stack frame object.
1755   unsigned SrcAlign = DAG.getDataLayout().getPrefTypeAlignment(
1756       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1757   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
1758 
1759   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1760   int SPFI = StackPtrFI->getIndex();
1761   MachinePointerInfo PtrInfo =
1762       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1763 
1764   unsigned SrcSize = SrcOp.getValueSizeInBits();
1765   unsigned SlotSize = SlotVT.getSizeInBits();
1766   unsigned DestSize = DestVT.getSizeInBits();
1767   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1768   unsigned DestAlign = DAG.getDataLayout().getPrefTypeAlignment(DestType);
1769 
1770   // Emit a store to the stack slot.  Use a truncstore if the input value is
1771   // later than DestVT.
1772   SDValue Store;
1773 
1774   if (SrcSize > SlotSize)
1775     Store = DAG.getTruncStore(Chain, dl, SrcOp, FIPtr, PtrInfo,
1776                               SlotVT, SrcAlign);
1777   else {
1778     assert(SrcSize == SlotSize && "Invalid store");
1779     Store =
1780         DAG.getStore(Chain, dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1781   }
1782 
1783   // Result is a load from the stack slot.
1784   if (SlotSize == DestSize)
1785     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1786 
1787   assert(SlotSize < DestSize && "Unknown extension!");
1788   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1789                         DestAlign);
1790 }
1791 
1792 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1793   SDLoc dl(Node);
1794   // Create a vector sized/aligned stack slot, store the value to element #0,
1795   // then load the whole vector back out.
1796   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1797 
1798   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1799   int SPFI = StackPtrFI->getIndex();
1800 
1801   SDValue Ch = DAG.getTruncStore(
1802       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1803       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1804       Node->getValueType(0).getVectorElementType());
1805   return DAG.getLoad(
1806       Node->getValueType(0), dl, Ch, StackPtr,
1807       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1808 }
1809 
1810 static bool
1811 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1812                      const TargetLowering &TLI, SDValue &Res) {
1813   unsigned NumElems = Node->getNumOperands();
1814   SDLoc dl(Node);
1815   EVT VT = Node->getValueType(0);
1816 
1817   // Try to group the scalars into pairs, shuffle the pairs together, then
1818   // shuffle the pairs of pairs together, etc. until the vector has
1819   // been built. This will work only if all of the necessary shuffle masks
1820   // are legal.
1821 
1822   // We do this in two phases; first to check the legality of the shuffles,
1823   // and next, assuming that all shuffles are legal, to create the new nodes.
1824   for (int Phase = 0; Phase < 2; ++Phase) {
1825     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1826                                                               NewIntermedVals;
1827     for (unsigned i = 0; i < NumElems; ++i) {
1828       SDValue V = Node->getOperand(i);
1829       if (V.isUndef())
1830         continue;
1831 
1832       SDValue Vec;
1833       if (Phase)
1834         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1835       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1836     }
1837 
1838     while (IntermedVals.size() > 2) {
1839       NewIntermedVals.clear();
1840       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1841         // This vector and the next vector are shuffled together (simply to
1842         // append the one to the other).
1843         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1844 
1845         SmallVector<int, 16> FinalIndices;
1846         FinalIndices.reserve(IntermedVals[i].second.size() +
1847                              IntermedVals[i+1].second.size());
1848 
1849         int k = 0;
1850         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1851              ++j, ++k) {
1852           ShuffleVec[k] = j;
1853           FinalIndices.push_back(IntermedVals[i].second[j]);
1854         }
1855         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1856              ++j, ++k) {
1857           ShuffleVec[k] = NumElems + j;
1858           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1859         }
1860 
1861         SDValue Shuffle;
1862         if (Phase)
1863           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1864                                          IntermedVals[i+1].first,
1865                                          ShuffleVec);
1866         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1867           return false;
1868         NewIntermedVals.push_back(
1869             std::make_pair(Shuffle, std::move(FinalIndices)));
1870       }
1871 
1872       // If we had an odd number of defined values, then append the last
1873       // element to the array of new vectors.
1874       if ((IntermedVals.size() & 1) != 0)
1875         NewIntermedVals.push_back(IntermedVals.back());
1876 
1877       IntermedVals.swap(NewIntermedVals);
1878     }
1879 
1880     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1881            "Invalid number of intermediate vectors");
1882     SDValue Vec1 = IntermedVals[0].first;
1883     SDValue Vec2;
1884     if (IntermedVals.size() > 1)
1885       Vec2 = IntermedVals[1].first;
1886     else if (Phase)
1887       Vec2 = DAG.getUNDEF(VT);
1888 
1889     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1890     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1891       ShuffleVec[IntermedVals[0].second[i]] = i;
1892     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1893       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1894 
1895     if (Phase)
1896       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1897     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1898       return false;
1899   }
1900 
1901   return true;
1902 }
1903 
1904 /// Expand a BUILD_VECTOR node on targets that don't
1905 /// support the operation, but do support the resultant vector type.
1906 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1907   unsigned NumElems = Node->getNumOperands();
1908   SDValue Value1, Value2;
1909   SDLoc dl(Node);
1910   EVT VT = Node->getValueType(0);
1911   EVT OpVT = Node->getOperand(0).getValueType();
1912   EVT EltVT = VT.getVectorElementType();
1913 
1914   // If the only non-undef value is the low element, turn this into a
1915   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1916   bool isOnlyLowElement = true;
1917   bool MoreThanTwoValues = false;
1918   bool isConstant = true;
1919   for (unsigned i = 0; i < NumElems; ++i) {
1920     SDValue V = Node->getOperand(i);
1921     if (V.isUndef())
1922       continue;
1923     if (i > 0)
1924       isOnlyLowElement = false;
1925     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1926       isConstant = false;
1927 
1928     if (!Value1.getNode()) {
1929       Value1 = V;
1930     } else if (!Value2.getNode()) {
1931       if (V != Value1)
1932         Value2 = V;
1933     } else if (V != Value1 && V != Value2) {
1934       MoreThanTwoValues = true;
1935     }
1936   }
1937 
1938   if (!Value1.getNode())
1939     return DAG.getUNDEF(VT);
1940 
1941   if (isOnlyLowElement)
1942     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1943 
1944   // If all elements are constants, create a load from the constant pool.
1945   if (isConstant) {
1946     SmallVector<Constant*, 16> CV;
1947     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1948       if (ConstantFPSDNode *V =
1949           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1950         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1951       } else if (ConstantSDNode *V =
1952                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1953         if (OpVT==EltVT)
1954           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1955         else {
1956           // If OpVT and EltVT don't match, EltVT is not legal and the
1957           // element values have been promoted/truncated earlier.  Undo this;
1958           // we don't want a v16i8 to become a v16i32 for example.
1959           const ConstantInt *CI = V->getConstantIntValue();
1960           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1961                                         CI->getZExtValue()));
1962         }
1963       } else {
1964         assert(Node->getOperand(i).isUndef());
1965         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1966         CV.push_back(UndefValue::get(OpNTy));
1967       }
1968     }
1969     Constant *CP = ConstantVector::get(CV);
1970     SDValue CPIdx =
1971         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1972     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
1973     return DAG.getLoad(
1974         VT, dl, DAG.getEntryNode(), CPIdx,
1975         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1976         Alignment);
1977   }
1978 
1979   SmallSet<SDValue, 16> DefinedValues;
1980   for (unsigned i = 0; i < NumElems; ++i) {
1981     if (Node->getOperand(i).isUndef())
1982       continue;
1983     DefinedValues.insert(Node->getOperand(i));
1984   }
1985 
1986   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1987     if (!MoreThanTwoValues) {
1988       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1989       for (unsigned i = 0; i < NumElems; ++i) {
1990         SDValue V = Node->getOperand(i);
1991         if (V.isUndef())
1992           continue;
1993         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1994       }
1995       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1996         // Get the splatted value into the low element of a vector register.
1997         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1998         SDValue Vec2;
1999         if (Value2.getNode())
2000           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
2001         else
2002           Vec2 = DAG.getUNDEF(VT);
2003 
2004         // Return shuffle(LowValVec, undef, <0,0,0,0>)
2005         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
2006       }
2007     } else {
2008       SDValue Res;
2009       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
2010         return Res;
2011     }
2012   }
2013 
2014   // Otherwise, we can't handle this case efficiently.
2015   return ExpandVectorBuildThroughStack(Node);
2016 }
2017 
2018 SDValue SelectionDAGLegalize::ExpandSPLAT_VECTOR(SDNode *Node) {
2019   SDLoc DL(Node);
2020   EVT VT = Node->getValueType(0);
2021   SDValue SplatVal = Node->getOperand(0);
2022 
2023   return DAG.getSplatBuildVector(VT, DL, SplatVal);
2024 }
2025 
2026 // Expand a node into a call to a libcall.  If the result value
2027 // does not fit into a register, return the lo part and set the hi part to the
2028 // by-reg argument.  If it does fit into a single register, return the result
2029 // and leave the Hi part unset.
2030 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
2031                                             bool isSigned) {
2032   TargetLowering::ArgListTy Args;
2033   TargetLowering::ArgListEntry Entry;
2034   for (const SDValue &Op : Node->op_values()) {
2035     EVT ArgVT = Op.getValueType();
2036     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2037     Entry.Node = Op;
2038     Entry.Ty = ArgTy;
2039     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2040     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2041     Args.push_back(Entry);
2042   }
2043   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2044                                          TLI.getPointerTy(DAG.getDataLayout()));
2045 
2046   EVT RetVT = Node->getValueType(0);
2047   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2048 
2049   // By default, the input chain to this libcall is the entry node of the
2050   // function. If the libcall is going to be emitted as a tail call then
2051   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2052   // node which is being folded has a non-entry input chain.
2053   SDValue InChain = DAG.getEntryNode();
2054 
2055   // isTailCall may be true since the callee does not reference caller stack
2056   // frame. Check if it's in the right position and that the return types match.
2057   SDValue TCChain = InChain;
2058   const Function &F = DAG.getMachineFunction().getFunction();
2059   bool isTailCall =
2060       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2061       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2062   if (isTailCall)
2063     InChain = TCChain;
2064 
2065   TargetLowering::CallLoweringInfo CLI(DAG);
2066   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2067   CLI.setDebugLoc(SDLoc(Node))
2068       .setChain(InChain)
2069       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2070                     std::move(Args))
2071       .setTailCall(isTailCall)
2072       .setSExtResult(signExtend)
2073       .setZExtResult(!signExtend)
2074       .setIsPostTypeLegalization(true);
2075 
2076   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2077 
2078   if (!CallInfo.second.getNode()) {
2079     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump(&DAG));
2080     // It's a tailcall, return the chain (which is the DAG root).
2081     return DAG.getRoot();
2082   }
2083 
2084   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump(&DAG));
2085   return CallInfo.first;
2086 }
2087 
2088 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2089                                            RTLIB::Libcall Call_F32,
2090                                            RTLIB::Libcall Call_F64,
2091                                            RTLIB::Libcall Call_F80,
2092                                            RTLIB::Libcall Call_F128,
2093                                            RTLIB::Libcall Call_PPCF128,
2094                                            SmallVectorImpl<SDValue> &Results) {
2095   RTLIB::Libcall LC;
2096   switch (Node->getSimpleValueType(0).SimpleTy) {
2097   default: llvm_unreachable("Unexpected request for libcall!");
2098   case MVT::f32: LC = Call_F32; break;
2099   case MVT::f64: LC = Call_F64; break;
2100   case MVT::f80: LC = Call_F80; break;
2101   case MVT::f128: LC = Call_F128; break;
2102   case MVT::ppcf128: LC = Call_PPCF128; break;
2103   }
2104 
2105   if (Node->isStrictFPOpcode()) {
2106     EVT RetVT = Node->getValueType(0);
2107     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
2108     TargetLowering::MakeLibCallOptions CallOptions;
2109     // FIXME: This doesn't support tail calls.
2110     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2111                                                       Ops, CallOptions,
2112                                                       SDLoc(Node),
2113                                                       Node->getOperand(0));
2114     Results.push_back(Tmp.first);
2115     Results.push_back(Tmp.second);
2116   } else {
2117     SDValue Tmp = ExpandLibCall(LC, Node, false);
2118     Results.push_back(Tmp);
2119   }
2120 }
2121 
2122 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2123                                                RTLIB::Libcall Call_I8,
2124                                                RTLIB::Libcall Call_I16,
2125                                                RTLIB::Libcall Call_I32,
2126                                                RTLIB::Libcall Call_I64,
2127                                                RTLIB::Libcall Call_I128) {
2128   RTLIB::Libcall LC;
2129   switch (Node->getSimpleValueType(0).SimpleTy) {
2130   default: llvm_unreachable("Unexpected request for libcall!");
2131   case MVT::i8:   LC = Call_I8; break;
2132   case MVT::i16:  LC = Call_I16; break;
2133   case MVT::i32:  LC = Call_I32; break;
2134   case MVT::i64:  LC = Call_I64; break;
2135   case MVT::i128: LC = Call_I128; break;
2136   }
2137   return ExpandLibCall(LC, Node, isSigned);
2138 }
2139 
2140 /// Expand the node to a libcall based on first argument type (for instance
2141 /// lround and its variant).
2142 void SelectionDAGLegalize::ExpandArgFPLibCall(SDNode* Node,
2143                                             RTLIB::Libcall Call_F32,
2144                                             RTLIB::Libcall Call_F64,
2145                                             RTLIB::Libcall Call_F80,
2146                                             RTLIB::Libcall Call_F128,
2147                                             RTLIB::Libcall Call_PPCF128,
2148                                             SmallVectorImpl<SDValue> &Results) {
2149   EVT InVT = Node->getOperand(Node->isStrictFPOpcode() ? 1 : 0).getValueType();
2150 
2151   RTLIB::Libcall LC;
2152   switch (InVT.getSimpleVT().SimpleTy) {
2153   default: llvm_unreachable("Unexpected request for libcall!");
2154   case MVT::f32:     LC = Call_F32; break;
2155   case MVT::f64:     LC = Call_F64; break;
2156   case MVT::f80:     LC = Call_F80; break;
2157   case MVT::f128:    LC = Call_F128; break;
2158   case MVT::ppcf128: LC = Call_PPCF128; break;
2159   }
2160 
2161   if (Node->isStrictFPOpcode()) {
2162     EVT RetVT = Node->getValueType(0);
2163     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
2164     TargetLowering::MakeLibCallOptions CallOptions;
2165     // FIXME: This doesn't support tail calls.
2166     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2167                                                       Ops, CallOptions,
2168                                                       SDLoc(Node),
2169                                                       Node->getOperand(0));
2170     Results.push_back(Tmp.first);
2171     Results.push_back(Tmp.second);
2172   } else {
2173     SDValue Tmp = ExpandLibCall(LC, Node, false);
2174     Results.push_back(Tmp);
2175   }
2176 }
2177 
2178 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2179 void
2180 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2181                                           SmallVectorImpl<SDValue> &Results) {
2182   unsigned Opcode = Node->getOpcode();
2183   bool isSigned = Opcode == ISD::SDIVREM;
2184 
2185   RTLIB::Libcall LC;
2186   switch (Node->getSimpleValueType(0).SimpleTy) {
2187   default: llvm_unreachable("Unexpected request for libcall!");
2188   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2189   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2190   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2191   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2192   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2193   }
2194 
2195   // The input chain to this libcall is the entry node of the function.
2196   // Legalizing the call will automatically add the previous call to the
2197   // dependence.
2198   SDValue InChain = DAG.getEntryNode();
2199 
2200   EVT RetVT = Node->getValueType(0);
2201   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2202 
2203   TargetLowering::ArgListTy Args;
2204   TargetLowering::ArgListEntry Entry;
2205   for (const SDValue &Op : Node->op_values()) {
2206     EVT ArgVT = Op.getValueType();
2207     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2208     Entry.Node = Op;
2209     Entry.Ty = ArgTy;
2210     Entry.IsSExt = isSigned;
2211     Entry.IsZExt = !isSigned;
2212     Args.push_back(Entry);
2213   }
2214 
2215   // Also pass the return address of the remainder.
2216   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2217   Entry.Node = FIPtr;
2218   Entry.Ty = RetTy->getPointerTo();
2219   Entry.IsSExt = isSigned;
2220   Entry.IsZExt = !isSigned;
2221   Args.push_back(Entry);
2222 
2223   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2224                                          TLI.getPointerTy(DAG.getDataLayout()));
2225 
2226   SDLoc dl(Node);
2227   TargetLowering::CallLoweringInfo CLI(DAG);
2228   CLI.setDebugLoc(dl)
2229       .setChain(InChain)
2230       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2231                     std::move(Args))
2232       .setSExtResult(isSigned)
2233       .setZExtResult(!isSigned);
2234 
2235   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2236 
2237   // Remainder is loaded back from the stack frame.
2238   SDValue Rem =
2239       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2240   Results.push_back(CallInfo.first);
2241   Results.push_back(Rem);
2242 }
2243 
2244 /// Return true if sincos libcall is available.
2245 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2246   RTLIB::Libcall LC;
2247   switch (Node->getSimpleValueType(0).SimpleTy) {
2248   default: llvm_unreachable("Unexpected request for libcall!");
2249   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2250   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2251   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2252   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2253   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2254   }
2255   return TLI.getLibcallName(LC) != nullptr;
2256 }
2257 
2258 /// Only issue sincos libcall if both sin and cos are needed.
2259 static bool useSinCos(SDNode *Node) {
2260   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2261     ? ISD::FCOS : ISD::FSIN;
2262 
2263   SDValue Op0 = Node->getOperand(0);
2264   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2265        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2266     SDNode *User = *UI;
2267     if (User == Node)
2268       continue;
2269     // The other user might have been turned into sincos already.
2270     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2271       return true;
2272   }
2273   return false;
2274 }
2275 
2276 /// Issue libcalls to sincos to compute sin / cos pairs.
2277 void
2278 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2279                                           SmallVectorImpl<SDValue> &Results) {
2280   RTLIB::Libcall LC;
2281   switch (Node->getSimpleValueType(0).SimpleTy) {
2282   default: llvm_unreachable("Unexpected request for libcall!");
2283   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2284   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2285   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2286   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2287   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2288   }
2289 
2290   // The input chain to this libcall is the entry node of the function.
2291   // Legalizing the call will automatically add the previous call to the
2292   // dependence.
2293   SDValue InChain = DAG.getEntryNode();
2294 
2295   EVT RetVT = Node->getValueType(0);
2296   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2297 
2298   TargetLowering::ArgListTy Args;
2299   TargetLowering::ArgListEntry Entry;
2300 
2301   // Pass the argument.
2302   Entry.Node = Node->getOperand(0);
2303   Entry.Ty = RetTy;
2304   Entry.IsSExt = false;
2305   Entry.IsZExt = false;
2306   Args.push_back(Entry);
2307 
2308   // Pass the return address of sin.
2309   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2310   Entry.Node = SinPtr;
2311   Entry.Ty = RetTy->getPointerTo();
2312   Entry.IsSExt = false;
2313   Entry.IsZExt = false;
2314   Args.push_back(Entry);
2315 
2316   // Also pass the return address of the cos.
2317   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2318   Entry.Node = CosPtr;
2319   Entry.Ty = RetTy->getPointerTo();
2320   Entry.IsSExt = false;
2321   Entry.IsZExt = false;
2322   Args.push_back(Entry);
2323 
2324   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2325                                          TLI.getPointerTy(DAG.getDataLayout()));
2326 
2327   SDLoc dl(Node);
2328   TargetLowering::CallLoweringInfo CLI(DAG);
2329   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2330       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2331       std::move(Args));
2332 
2333   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2334 
2335   Results.push_back(
2336       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2337   Results.push_back(
2338       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2339 }
2340 
2341 /// This function is responsible for legalizing a
2342 /// INT_TO_FP operation of the specified operand when the target requests that
2343 /// we expand it.  At this point, we know that the result and operand types are
2344 /// legal for the target.
2345 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(SDNode *Node,
2346                                                    SDValue &Chain) {
2347   bool isSigned = (Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
2348                    Node->getOpcode() == ISD::SINT_TO_FP);
2349   EVT DestVT = Node->getValueType(0);
2350   SDLoc dl(Node);
2351   unsigned OpNo = Node->isStrictFPOpcode() ? 1 : 0;
2352   SDValue Op0 = Node->getOperand(OpNo);
2353   EVT SrcVT = Op0.getValueType();
2354 
2355   // TODO: Should any fast-math-flags be set for the created nodes?
2356   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2357   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2358     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2359                          "expansion\n");
2360 
2361     // Get the stack frame index of a 8 byte buffer.
2362     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2363 
2364     // word offset constant for Hi/Lo address computation
2365     SDValue WordOff = DAG.getConstant(sizeof(int), dl,
2366                                       StackSlot.getValueType());
2367     // set up Hi and Lo (into buffer) address based on endian
2368     SDValue Hi = StackSlot;
2369     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
2370                              StackSlot, WordOff);
2371     if (DAG.getDataLayout().isLittleEndian())
2372       std::swap(Hi, Lo);
2373 
2374     // if signed map to unsigned space
2375     SDValue Op0Mapped;
2376     if (isSigned) {
2377       // constant used to invert sign bit (signed to unsigned mapping)
2378       SDValue SignBit = DAG.getConstant(0x80000000u, dl, MVT::i32);
2379       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
2380     } else {
2381       Op0Mapped = Op0;
2382     }
2383     // store the lo of the constructed double - based on integer input
2384     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl, Op0Mapped, Lo,
2385                                   MachinePointerInfo());
2386     // initial hi portion of constructed double
2387     SDValue InitialHi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2388     // store the hi of the constructed double - biased exponent
2389     SDValue Store2 =
2390         DAG.getStore(Store1, dl, InitialHi, Hi, MachinePointerInfo());
2391     // load the constructed double
2392     SDValue Load =
2393         DAG.getLoad(MVT::f64, dl, Store2, StackSlot, MachinePointerInfo());
2394     // FP constant to bias correct the final result
2395     SDValue Bias = DAG.getConstantFP(isSigned ?
2396                                      BitsToDouble(0x4330000080000000ULL) :
2397                                      BitsToDouble(0x4330000000000000ULL),
2398                                      dl, MVT::f64);
2399     // Subtract the bias and get the final result.
2400     SDValue Sub;
2401     SDValue Result;
2402     if (Node->isStrictFPOpcode()) {
2403       Sub = DAG.getNode(ISD::STRICT_FSUB, dl, {MVT::f64, MVT::Other},
2404                         {Node->getOperand(0), Load, Bias});
2405       Chain = Sub.getValue(1);
2406       if (DestVT != Sub.getValueType()) {
2407         std::pair<SDValue, SDValue> ResultPair;
2408         ResultPair =
2409             DAG.getStrictFPExtendOrRound(Sub, Chain, dl, DestVT);
2410         Result = ResultPair.first;
2411         Chain = ResultPair.second;
2412       }
2413       else
2414         Result = Sub;
2415     } else {
2416       Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2417       Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2418     }
2419     return Result;
2420   }
2421   // Code below here assumes !isSigned without checking again.
2422   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2423 
2424   // TODO: Generalize this for use with other types.
2425   if ((SrcVT == MVT::i32 || SrcVT == MVT::i64) && DestVT == MVT::f32) {
2426     LLVM_DEBUG(dbgs() << "Converting unsigned i32/i64 to f32\n");
2427     // For unsigned conversions, convert them to signed conversions using the
2428     // algorithm from the x86_64 __floatundisf in compiler_rt. That method
2429     // should be valid for i32->f32 as well.
2430 
2431     // TODO: This really should be implemented using a branch rather than a
2432     // select.  We happen to get lucky and machinesink does the right
2433     // thing most of the time.  This would be a good candidate for a
2434     // pseudo-op, or, even better, for whole-function isel.
2435     EVT SetCCVT = getSetCCResultType(SrcVT);
2436 
2437     SDValue SignBitTest = DAG.getSetCC(
2438         dl, SetCCVT, Op0, DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2439 
2440     EVT ShiftVT = TLI.getShiftAmountTy(SrcVT, DAG.getDataLayout());
2441     SDValue ShiftConst = DAG.getConstant(1, dl, ShiftVT);
2442     SDValue Shr = DAG.getNode(ISD::SRL, dl, SrcVT, Op0, ShiftConst);
2443     SDValue AndConst = DAG.getConstant(1, dl, SrcVT);
2444     SDValue And = DAG.getNode(ISD::AND, dl, SrcVT, Op0, AndConst);
2445     SDValue Or = DAG.getNode(ISD::OR, dl, SrcVT, And, Shr);
2446 
2447     SDValue Slow, Fast;
2448     if (Node->isStrictFPOpcode()) {
2449       // In strict mode, we must avoid spurious exceptions, and therefore
2450       // must make sure to only emit a single STRICT_SINT_TO_FP.
2451       SDValue InCvt = DAG.getSelect(dl, SrcVT, SignBitTest, Or, Op0);
2452       Fast = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2453                          { Node->getOperand(0), InCvt });
2454       Slow = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2455                          { Fast.getValue(1), Fast, Fast });
2456       Chain = Slow.getValue(1);
2457       // The STRICT_SINT_TO_FP inherits the exception mode from the
2458       // incoming STRICT_UINT_TO_FP node; the STRICT_FADD node can
2459       // never raise any exception.
2460       SDNodeFlags Flags;
2461       Flags.setNoFPExcept(Node->getFlags().hasNoFPExcept());
2462       Fast->setFlags(Flags);
2463       Flags.setNoFPExcept(true);
2464       Slow->setFlags(Flags);
2465     } else {
2466       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Or);
2467       Slow = DAG.getNode(ISD::FADD, dl, DestVT, SignCvt, SignCvt);
2468       Fast = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2469     }
2470 
2471     return DAG.getSelect(dl, DestVT, SignBitTest, Slow, Fast);
2472   }
2473 
2474   // The following optimization is valid only if every value in SrcVT (when
2475   // treated as signed) is representable in DestVT.  Check that the mantissa
2476   // size of DestVT is >= than the number of bits in SrcVT -1.
2477   assert(APFloat::semanticsPrecision(DAG.EVTToAPFloatSemantics(DestVT)) >=
2478              SrcVT.getSizeInBits() - 1 &&
2479          "Cannot perform lossless SINT_TO_FP!");
2480 
2481   SDValue Tmp1;
2482   if (Node->isStrictFPOpcode()) {
2483     Tmp1 = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2484                        { Node->getOperand(0), Op0 });
2485   } else
2486     Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2487 
2488   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2489                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2490   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2491           Four = DAG.getIntPtrConstant(4, dl);
2492   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2493                                     SignSet, Four, Zero);
2494 
2495   // If the sign bit of the integer is set, the large number will be treated
2496   // as a negative number.  To counteract this, the dynamic code adds an
2497   // offset depending on the data type.
2498   uint64_t FF;
2499   switch (SrcVT.getSimpleVT().SimpleTy) {
2500   default: llvm_unreachable("Unsupported integer type!");
2501   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2502   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2503   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2504   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2505   }
2506   if (DAG.getDataLayout().isLittleEndian())
2507     FF <<= 32;
2508   Constant *FudgeFactor = ConstantInt::get(
2509                                        Type::getInt64Ty(*DAG.getContext()), FF);
2510 
2511   SDValue CPIdx =
2512       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2513   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
2514   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2515   Alignment = std::min(Alignment, 4u);
2516   SDValue FudgeInReg;
2517   if (DestVT == MVT::f32)
2518     FudgeInReg = DAG.getLoad(
2519         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2520         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2521         Alignment);
2522   else {
2523     SDValue Load = DAG.getExtLoad(
2524         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2525         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2526         Alignment);
2527     HandleSDNode Handle(Load);
2528     LegalizeOp(Load.getNode());
2529     FudgeInReg = Handle.getValue();
2530   }
2531 
2532   if (Node->isStrictFPOpcode()) {
2533     SDValue Result = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2534                                  { Tmp1.getValue(1), Tmp1, FudgeInReg });
2535     Chain = Result.getValue(1);
2536     return Result;
2537   }
2538 
2539   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2540 }
2541 
2542 /// This function is responsible for legalizing a
2543 /// *INT_TO_FP operation of the specified operand when the target requests that
2544 /// we promote it.  At this point, we know that the result and operand types are
2545 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2546 /// operation that takes a larger input.
2547 void SelectionDAGLegalize::PromoteLegalINT_TO_FP(
2548     SDNode *N, const SDLoc &dl, SmallVectorImpl<SDValue> &Results) {
2549   bool IsStrict = N->isStrictFPOpcode();
2550   bool IsSigned = N->getOpcode() == ISD::SINT_TO_FP ||
2551                   N->getOpcode() == ISD::STRICT_SINT_TO_FP;
2552   EVT DestVT = N->getValueType(0);
2553   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2554   unsigned UIntOp = IsStrict ? ISD::STRICT_UINT_TO_FP : ISD::UINT_TO_FP;
2555   unsigned SIntOp = IsStrict ? ISD::STRICT_SINT_TO_FP : ISD::SINT_TO_FP;
2556 
2557   // First step, figure out the appropriate *INT_TO_FP operation to use.
2558   EVT NewInTy = LegalOp.getValueType();
2559 
2560   unsigned OpToUse = 0;
2561 
2562   // Scan for the appropriate larger type to use.
2563   while (true) {
2564     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2565     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2566 
2567     // If the target supports SINT_TO_FP of this type, use it.
2568     if (TLI.isOperationLegalOrCustom(SIntOp, NewInTy)) {
2569       OpToUse = SIntOp;
2570       break;
2571     }
2572     if (IsSigned)
2573       continue;
2574 
2575     // If the target supports UINT_TO_FP of this type, use it.
2576     if (TLI.isOperationLegalOrCustom(UIntOp, NewInTy)) {
2577       OpToUse = UIntOp;
2578       break;
2579     }
2580 
2581     // Otherwise, try a larger type.
2582   }
2583 
2584   // Okay, we found the operation and type to use.  Zero extend our input to the
2585   // desired type then run the operation on it.
2586   if (IsStrict) {
2587     SDValue Res =
2588         DAG.getNode(OpToUse, dl, {DestVT, MVT::Other},
2589                     {N->getOperand(0),
2590                      DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2591                                  dl, NewInTy, LegalOp)});
2592     Results.push_back(Res);
2593     Results.push_back(Res.getValue(1));
2594     return;
2595   }
2596 
2597   Results.push_back(
2598       DAG.getNode(OpToUse, dl, DestVT,
2599                   DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2600                               dl, NewInTy, LegalOp)));
2601 }
2602 
2603 /// This function is responsible for legalizing a
2604 /// FP_TO_*INT operation of the specified operand when the target requests that
2605 /// we promote it.  At this point, we know that the result and operand types are
2606 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2607 /// operation that returns a larger result.
2608 void SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
2609                                                  SmallVectorImpl<SDValue> &Results) {
2610   bool IsStrict = N->isStrictFPOpcode();
2611   bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT ||
2612                   N->getOpcode() == ISD::STRICT_FP_TO_SINT;
2613   EVT DestVT = N->getValueType(0);
2614   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2615   // First step, figure out the appropriate FP_TO*INT operation to use.
2616   EVT NewOutTy = DestVT;
2617 
2618   unsigned OpToUse = 0;
2619 
2620   // Scan for the appropriate larger type to use.
2621   while (true) {
2622     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2623     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2624 
2625     // A larger signed type can hold all unsigned values of the requested type,
2626     // so using FP_TO_SINT is valid
2627     OpToUse = IsStrict ? ISD::STRICT_FP_TO_SINT : ISD::FP_TO_SINT;
2628     if (TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2629       break;
2630 
2631     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2632     OpToUse = IsStrict ? ISD::STRICT_FP_TO_UINT : ISD::FP_TO_UINT;
2633     if (!IsSigned && TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2634       break;
2635 
2636     // Otherwise, try a larger type.
2637   }
2638 
2639   // Okay, we found the operation and type to use.
2640   SDValue Operation;
2641   if (IsStrict) {
2642     SDVTList VTs = DAG.getVTList(NewOutTy, MVT::Other);
2643     Operation = DAG.getNode(OpToUse, dl, VTs, N->getOperand(0), LegalOp);
2644   } else
2645     Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2646 
2647   // Truncate the result of the extended FP_TO_*INT operation to the desired
2648   // size.
2649   SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2650   Results.push_back(Trunc);
2651   if (IsStrict)
2652     Results.push_back(Operation.getValue(1));
2653 }
2654 
2655 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
2656 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2657   EVT VT = Op.getValueType();
2658   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2659   unsigned Sz = VT.getScalarSizeInBits();
2660 
2661   SDValue Tmp, Tmp2, Tmp3;
2662 
2663   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2664   // and finally the i1 pairs.
2665   // TODO: We can easily support i4/i2 legal types if any target ever does.
2666   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2667     // Create the masks - repeating the pattern every byte.
2668     APInt MaskHi4 = APInt::getSplat(Sz, APInt(8, 0xF0));
2669     APInt MaskHi2 = APInt::getSplat(Sz, APInt(8, 0xCC));
2670     APInt MaskHi1 = APInt::getSplat(Sz, APInt(8, 0xAA));
2671     APInt MaskLo4 = APInt::getSplat(Sz, APInt(8, 0x0F));
2672     APInt MaskLo2 = APInt::getSplat(Sz, APInt(8, 0x33));
2673     APInt MaskLo1 = APInt::getSplat(Sz, APInt(8, 0x55));
2674 
2675     // BSWAP if the type is wider than a single byte.
2676     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2677 
2678     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2679     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2680     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2681     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, SHVT));
2682     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, SHVT));
2683     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2684 
2685     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2686     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2687     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2688     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, SHVT));
2689     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, SHVT));
2690     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2691 
2692     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2693     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2694     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2695     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, SHVT));
2696     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, SHVT));
2697     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2698     return Tmp;
2699   }
2700 
2701   Tmp = DAG.getConstant(0, dl, VT);
2702   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2703     if (I < J)
2704       Tmp2 =
2705           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2706     else
2707       Tmp2 =
2708           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2709 
2710     APInt Shift(Sz, 1);
2711     Shift <<= J;
2712     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2713     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2714   }
2715 
2716   return Tmp;
2717 }
2718 
2719 /// Open code the operations for BSWAP of the specified operation.
2720 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2721   EVT VT = Op.getValueType();
2722   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2723   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2724   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2725   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2726   case MVT::i16:
2727     // Use a rotate by 8. This can be further expanded if necessary.
2728     return DAG.getNode(ISD::ROTL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2729   case MVT::i32:
2730     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2731     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2732     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2733     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2734     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2735                        DAG.getConstant(0xFF0000, dl, VT));
2736     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2737     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2738     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2739     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2740   case MVT::i64:
2741     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2742     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2743     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2744     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2745     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2746     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2747     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2748     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2749     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2750                        DAG.getConstant(255ULL<<48, dl, VT));
2751     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2752                        DAG.getConstant(255ULL<<40, dl, VT));
2753     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2754                        DAG.getConstant(255ULL<<32, dl, VT));
2755     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2756                        DAG.getConstant(255ULL<<24, dl, VT));
2757     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2758                        DAG.getConstant(255ULL<<16, dl, VT));
2759     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2760                        DAG.getConstant(255ULL<<8 , dl, VT));
2761     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2762     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2763     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2764     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2765     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2766     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2767     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2768   }
2769 }
2770 
2771 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2772   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2773   SmallVector<SDValue, 8> Results;
2774   SDLoc dl(Node);
2775   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2776   bool NeedInvert;
2777   switch (Node->getOpcode()) {
2778   case ISD::ABS:
2779     if (TLI.expandABS(Node, Tmp1, DAG))
2780       Results.push_back(Tmp1);
2781     break;
2782   case ISD::CTPOP:
2783     if (TLI.expandCTPOP(Node, Tmp1, DAG))
2784       Results.push_back(Tmp1);
2785     break;
2786   case ISD::CTLZ:
2787   case ISD::CTLZ_ZERO_UNDEF:
2788     if (TLI.expandCTLZ(Node, Tmp1, DAG))
2789       Results.push_back(Tmp1);
2790     break;
2791   case ISD::CTTZ:
2792   case ISD::CTTZ_ZERO_UNDEF:
2793     if (TLI.expandCTTZ(Node, Tmp1, DAG))
2794       Results.push_back(Tmp1);
2795     break;
2796   case ISD::BITREVERSE:
2797     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2798     break;
2799   case ISD::BSWAP:
2800     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2801     break;
2802   case ISD::FRAMEADDR:
2803   case ISD::RETURNADDR:
2804   case ISD::FRAME_TO_ARGS_OFFSET:
2805     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2806     break;
2807   case ISD::EH_DWARF_CFA: {
2808     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2809                                         TLI.getPointerTy(DAG.getDataLayout()));
2810     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2811                                  CfaArg.getValueType(),
2812                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2813                                              CfaArg.getValueType()),
2814                                  CfaArg);
2815     SDValue FA = DAG.getNode(
2816         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2817         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2818     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2819                                   FA, Offset));
2820     break;
2821   }
2822   case ISD::FLT_ROUNDS_:
2823     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2824     break;
2825   case ISD::EH_RETURN:
2826   case ISD::EH_LABEL:
2827   case ISD::PREFETCH:
2828   case ISD::VAEND:
2829   case ISD::EH_SJLJ_LONGJMP:
2830     // If the target didn't expand these, there's nothing to do, so just
2831     // preserve the chain and be done.
2832     Results.push_back(Node->getOperand(0));
2833     break;
2834   case ISD::READCYCLECOUNTER:
2835     // If the target didn't expand this, just return 'zero' and preserve the
2836     // chain.
2837     Results.append(Node->getNumValues() - 1,
2838                    DAG.getConstant(0, dl, Node->getValueType(0)));
2839     Results.push_back(Node->getOperand(0));
2840     break;
2841   case ISD::EH_SJLJ_SETJMP:
2842     // If the target didn't expand this, just return 'zero' and preserve the
2843     // chain.
2844     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2845     Results.push_back(Node->getOperand(0));
2846     break;
2847   case ISD::ATOMIC_LOAD: {
2848     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2849     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2850     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2851     SDValue Swap = DAG.getAtomicCmpSwap(
2852         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2853         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2854         cast<AtomicSDNode>(Node)->getMemOperand());
2855     Results.push_back(Swap.getValue(0));
2856     Results.push_back(Swap.getValue(1));
2857     break;
2858   }
2859   case ISD::ATOMIC_STORE: {
2860     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2861     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2862                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2863                                  Node->getOperand(0),
2864                                  Node->getOperand(1), Node->getOperand(2),
2865                                  cast<AtomicSDNode>(Node)->getMemOperand());
2866     Results.push_back(Swap.getValue(1));
2867     break;
2868   }
2869   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2870     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2871     // splits out the success value as a comparison. Expanding the resulting
2872     // ATOMIC_CMP_SWAP will produce a libcall.
2873     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2874     SDValue Res = DAG.getAtomicCmpSwap(
2875         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2876         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2877         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2878 
2879     SDValue ExtRes = Res;
2880     SDValue LHS = Res;
2881     SDValue RHS = Node->getOperand(1);
2882 
2883     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2884     EVT OuterType = Node->getValueType(0);
2885     switch (TLI.getExtendForAtomicOps()) {
2886     case ISD::SIGN_EXTEND:
2887       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2888                         DAG.getValueType(AtomicType));
2889       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2890                         Node->getOperand(2), DAG.getValueType(AtomicType));
2891       ExtRes = LHS;
2892       break;
2893     case ISD::ZERO_EXTEND:
2894       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2895                         DAG.getValueType(AtomicType));
2896       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2897       ExtRes = LHS;
2898       break;
2899     case ISD::ANY_EXTEND:
2900       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2901       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2902       break;
2903     default:
2904       llvm_unreachable("Invalid atomic op extension");
2905     }
2906 
2907     SDValue Success =
2908         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2909 
2910     Results.push_back(ExtRes.getValue(0));
2911     Results.push_back(Success);
2912     Results.push_back(Res.getValue(1));
2913     break;
2914   }
2915   case ISD::DYNAMIC_STACKALLOC:
2916     ExpandDYNAMIC_STACKALLOC(Node, Results);
2917     break;
2918   case ISD::MERGE_VALUES:
2919     for (unsigned i = 0; i < Node->getNumValues(); i++)
2920       Results.push_back(Node->getOperand(i));
2921     break;
2922   case ISD::UNDEF: {
2923     EVT VT = Node->getValueType(0);
2924     if (VT.isInteger())
2925       Results.push_back(DAG.getConstant(0, dl, VT));
2926     else {
2927       assert(VT.isFloatingPoint() && "Unknown value type!");
2928       Results.push_back(DAG.getConstantFP(0, dl, VT));
2929     }
2930     break;
2931   }
2932   case ISD::STRICT_FP_ROUND:
2933     // When strict mode is enforced we can't do expansion because it
2934     // does not honor the "strict" properties. Only libcall is allowed.
2935     if (TLI.isStrictFPEnabled())
2936       break;
2937     // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
2938     // since this operation is more efficient than stack operation.
2939     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2940                                        Node->getValueType(0))
2941         == TargetLowering::Legal)
2942       break;
2943     // We fall back to use stack operation when the FP_ROUND operation
2944     // isn't available.
2945     Tmp1 = EmitStackConvert(Node->getOperand(1),
2946                             Node->getValueType(0),
2947                             Node->getValueType(0), dl, Node->getOperand(0));
2948     ReplaceNode(Node, Tmp1.getNode());
2949     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_ROUND node\n");
2950     return true;
2951   case ISD::FP_ROUND:
2952   case ISD::BITCAST:
2953     Tmp1 = EmitStackConvert(Node->getOperand(0),
2954                             Node->getValueType(0),
2955                             Node->getValueType(0), dl);
2956     Results.push_back(Tmp1);
2957     break;
2958   case ISD::STRICT_FP_EXTEND:
2959     // When strict mode is enforced we can't do expansion because it
2960     // does not honor the "strict" properties. Only libcall is allowed.
2961     if (TLI.isStrictFPEnabled())
2962       break;
2963     // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
2964     // since this operation is more efficient than stack operation.
2965     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
2966                                        Node->getValueType(0))
2967         == TargetLowering::Legal)
2968       break;
2969     // We fall back to use stack operation when the FP_EXTEND operation
2970     // isn't available.
2971     Tmp1 = EmitStackConvert(Node->getOperand(1),
2972                             Node->getOperand(1).getValueType(),
2973                             Node->getValueType(0), dl, Node->getOperand(0));
2974     ReplaceNode(Node, Tmp1.getNode());
2975     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_EXTEND node\n");
2976     return true;
2977   case ISD::FP_EXTEND:
2978     Tmp1 = EmitStackConvert(Node->getOperand(0),
2979                             Node->getOperand(0).getValueType(),
2980                             Node->getValueType(0), dl);
2981     Results.push_back(Tmp1);
2982     break;
2983   case ISD::SIGN_EXTEND_INREG: {
2984     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2985     EVT VT = Node->getValueType(0);
2986 
2987     // An in-register sign-extend of a boolean is a negation:
2988     // 'true' (1) sign-extended is -1.
2989     // 'false' (0) sign-extended is 0.
2990     // However, we must mask the high bits of the source operand because the
2991     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
2992 
2993     // TODO: Do this for vectors too?
2994     if (ExtraVT.getSizeInBits() == 1) {
2995       SDValue One = DAG.getConstant(1, dl, VT);
2996       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
2997       SDValue Zero = DAG.getConstant(0, dl, VT);
2998       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
2999       Results.push_back(Neg);
3000       break;
3001     }
3002 
3003     // NOTE: we could fall back on load/store here too for targets without
3004     // SRA.  However, it is doubtful that any exist.
3005     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
3006     unsigned BitsDiff = VT.getScalarSizeInBits() -
3007                         ExtraVT.getScalarSizeInBits();
3008     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
3009     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
3010                        Node->getOperand(0), ShiftCst);
3011     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
3012     Results.push_back(Tmp1);
3013     break;
3014   }
3015   case ISD::UINT_TO_FP:
3016   case ISD::STRICT_UINT_TO_FP:
3017     if (TLI.expandUINT_TO_FP(Node, Tmp1, Tmp2, DAG)) {
3018       Results.push_back(Tmp1);
3019       if (Node->isStrictFPOpcode())
3020         Results.push_back(Tmp2);
3021       break;
3022     }
3023     LLVM_FALLTHROUGH;
3024   case ISD::SINT_TO_FP:
3025   case ISD::STRICT_SINT_TO_FP:
3026     Tmp1 = ExpandLegalINT_TO_FP(Node, Tmp2);
3027     Results.push_back(Tmp1);
3028     if (Node->isStrictFPOpcode())
3029       Results.push_back(Tmp2);
3030     break;
3031   case ISD::FP_TO_SINT:
3032     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
3033       Results.push_back(Tmp1);
3034     break;
3035   case ISD::STRICT_FP_TO_SINT:
3036     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG)) {
3037       ReplaceNode(Node, Tmp1.getNode());
3038       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_SINT node\n");
3039       return true;
3040     }
3041     break;
3042   case ISD::FP_TO_UINT:
3043     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG))
3044       Results.push_back(Tmp1);
3045     break;
3046   case ISD::STRICT_FP_TO_UINT:
3047     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG)) {
3048       // Relink the chain.
3049       DAG.ReplaceAllUsesOfValueWith(SDValue(Node,1), Tmp2);
3050       // Replace the new UINT result.
3051       ReplaceNodeWithValue(SDValue(Node, 0), Tmp1);
3052       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_UINT node\n");
3053       return true;
3054     }
3055     break;
3056   case ISD::VAARG:
3057     Results.push_back(DAG.expandVAArg(Node));
3058     Results.push_back(Results[0].getValue(1));
3059     break;
3060   case ISD::VACOPY:
3061     Results.push_back(DAG.expandVACopy(Node));
3062     break;
3063   case ISD::EXTRACT_VECTOR_ELT:
3064     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
3065       // This must be an access of the only element.  Return it.
3066       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
3067                          Node->getOperand(0));
3068     else
3069       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
3070     Results.push_back(Tmp1);
3071     break;
3072   case ISD::EXTRACT_SUBVECTOR:
3073     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
3074     break;
3075   case ISD::INSERT_SUBVECTOR:
3076     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3077     break;
3078   case ISD::CONCAT_VECTORS:
3079     Results.push_back(ExpandVectorBuildThroughStack(Node));
3080     break;
3081   case ISD::SCALAR_TO_VECTOR:
3082     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3083     break;
3084   case ISD::INSERT_VECTOR_ELT:
3085     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3086                                               Node->getOperand(1),
3087                                               Node->getOperand(2), dl));
3088     break;
3089   case ISD::VECTOR_SHUFFLE: {
3090     SmallVector<int, 32> NewMask;
3091     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3092 
3093     EVT VT = Node->getValueType(0);
3094     EVT EltVT = VT.getVectorElementType();
3095     SDValue Op0 = Node->getOperand(0);
3096     SDValue Op1 = Node->getOperand(1);
3097     if (!TLI.isTypeLegal(EltVT)) {
3098       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3099 
3100       // BUILD_VECTOR operands are allowed to be wider than the element type.
3101       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3102       // it.
3103       if (NewEltVT.bitsLT(EltVT)) {
3104         // Convert shuffle node.
3105         // If original node was v4i64 and the new EltVT is i32,
3106         // cast operands to v8i32 and re-build the mask.
3107 
3108         // Calculate new VT, the size of the new VT should be equal to original.
3109         EVT NewVT =
3110             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3111                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3112         assert(NewVT.bitsEq(VT));
3113 
3114         // cast operands to new VT
3115         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3116         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3117 
3118         // Convert the shuffle mask
3119         unsigned int factor =
3120                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3121 
3122         // EltVT gets smaller
3123         assert(factor > 0);
3124 
3125         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3126           if (Mask[i] < 0) {
3127             for (unsigned fi = 0; fi < factor; ++fi)
3128               NewMask.push_back(Mask[i]);
3129           }
3130           else {
3131             for (unsigned fi = 0; fi < factor; ++fi)
3132               NewMask.push_back(Mask[i]*factor+fi);
3133           }
3134         }
3135         Mask = NewMask;
3136         VT = NewVT;
3137       }
3138       EltVT = NewEltVT;
3139     }
3140     unsigned NumElems = VT.getVectorNumElements();
3141     SmallVector<SDValue, 16> Ops;
3142     for (unsigned i = 0; i != NumElems; ++i) {
3143       if (Mask[i] < 0) {
3144         Ops.push_back(DAG.getUNDEF(EltVT));
3145         continue;
3146       }
3147       unsigned Idx = Mask[i];
3148       if (Idx < NumElems)
3149         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3150                                   DAG.getVectorIdxConstant(Idx, dl)));
3151       else
3152         Ops.push_back(
3153             DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3154                         DAG.getVectorIdxConstant(Idx - NumElems, dl)));
3155     }
3156 
3157     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3158     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3159     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3160     Results.push_back(Tmp1);
3161     break;
3162   }
3163   case ISD::EXTRACT_ELEMENT: {
3164     EVT OpTy = Node->getOperand(0).getValueType();
3165     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3166       // 1 -> Hi
3167       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3168                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3169                                          TLI.getShiftAmountTy(
3170                                              Node->getOperand(0).getValueType(),
3171                                              DAG.getDataLayout())));
3172       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3173     } else {
3174       // 0 -> Lo
3175       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3176                          Node->getOperand(0));
3177     }
3178     Results.push_back(Tmp1);
3179     break;
3180   }
3181   case ISD::STACKSAVE:
3182     // Expand to CopyFromReg if the target set
3183     // StackPointerRegisterToSaveRestore.
3184     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3185       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3186                                            Node->getValueType(0)));
3187       Results.push_back(Results[0].getValue(1));
3188     } else {
3189       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3190       Results.push_back(Node->getOperand(0));
3191     }
3192     break;
3193   case ISD::STACKRESTORE:
3194     // Expand to CopyToReg if the target set
3195     // StackPointerRegisterToSaveRestore.
3196     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3197       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3198                                          Node->getOperand(1)));
3199     } else {
3200       Results.push_back(Node->getOperand(0));
3201     }
3202     break;
3203   case ISD::GET_DYNAMIC_AREA_OFFSET:
3204     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3205     Results.push_back(Results[0].getValue(0));
3206     break;
3207   case ISD::FCOPYSIGN:
3208     Results.push_back(ExpandFCOPYSIGN(Node));
3209     break;
3210   case ISD::FNEG:
3211     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3212     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3213     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3214     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3215                        Node->getOperand(0));
3216     Results.push_back(Tmp1);
3217     break;
3218   case ISD::FABS:
3219     Results.push_back(ExpandFABS(Node));
3220     break;
3221   case ISD::SMIN:
3222   case ISD::SMAX:
3223   case ISD::UMIN:
3224   case ISD::UMAX: {
3225     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3226     ISD::CondCode Pred;
3227     switch (Node->getOpcode()) {
3228     default: llvm_unreachable("How did we get here?");
3229     case ISD::SMAX: Pred = ISD::SETGT; break;
3230     case ISD::SMIN: Pred = ISD::SETLT; break;
3231     case ISD::UMAX: Pred = ISD::SETUGT; break;
3232     case ISD::UMIN: Pred = ISD::SETULT; break;
3233     }
3234     Tmp1 = Node->getOperand(0);
3235     Tmp2 = Node->getOperand(1);
3236     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3237     Results.push_back(Tmp1);
3238     break;
3239   }
3240   case ISD::FMINNUM:
3241   case ISD::FMAXNUM: {
3242     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3243       Results.push_back(Expanded);
3244     break;
3245   }
3246   case ISD::FSIN:
3247   case ISD::FCOS: {
3248     EVT VT = Node->getValueType(0);
3249     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3250     // fcos which share the same operand and both are used.
3251     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3252          isSinCosLibcallAvailable(Node, TLI))
3253         && useSinCos(Node)) {
3254       SDVTList VTs = DAG.getVTList(VT, VT);
3255       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3256       if (Node->getOpcode() == ISD::FCOS)
3257         Tmp1 = Tmp1.getValue(1);
3258       Results.push_back(Tmp1);
3259     }
3260     break;
3261   }
3262   case ISD::FMAD:
3263     llvm_unreachable("Illegal fmad should never be formed");
3264 
3265   case ISD::FP16_TO_FP:
3266     if (Node->getValueType(0) != MVT::f32) {
3267       // We can extend to types bigger than f32 in two steps without changing
3268       // the result. Since "f16 -> f32" is much more commonly available, give
3269       // CodeGen the option of emitting that before resorting to a libcall.
3270       SDValue Res =
3271           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3272       Results.push_back(
3273           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3274     }
3275     break;
3276   case ISD::STRICT_FP16_TO_FP:
3277     if (Node->getValueType(0) != MVT::f32) {
3278       // We can extend to types bigger than f32 in two steps without changing
3279       // the result. Since "f16 -> f32" is much more commonly available, give
3280       // CodeGen the option of emitting that before resorting to a libcall.
3281       SDValue Res =
3282           DAG.getNode(ISD::STRICT_FP16_TO_FP, dl, {MVT::f32, MVT::Other},
3283                       {Node->getOperand(0), Node->getOperand(1)});
3284       Res = DAG.getNode(ISD::STRICT_FP_EXTEND, dl,
3285                         {Node->getValueType(0), MVT::Other},
3286                         {Res.getValue(1), Res});
3287       Results.push_back(Res);
3288       Results.push_back(Res.getValue(1));
3289     }
3290     break;
3291   case ISD::FP_TO_FP16:
3292     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3293     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3294       SDValue Op = Node->getOperand(0);
3295       MVT SVT = Op.getSimpleValueType();
3296       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3297           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3298         // Under fastmath, we can expand this node into a fround followed by
3299         // a float-half conversion.
3300         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3301                                        DAG.getIntPtrConstant(0, dl));
3302         Results.push_back(
3303             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3304       }
3305     }
3306     break;
3307   case ISD::ConstantFP: {
3308     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3309     // Check to see if this FP immediate is already legal.
3310     // If this is a legal constant, turn it into a TargetConstantFP node.
3311     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0),
3312                           DAG.getMachineFunction().getFunction().hasOptSize()))
3313       Results.push_back(ExpandConstantFP(CFP, true));
3314     break;
3315   }
3316   case ISD::Constant: {
3317     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3318     Results.push_back(ExpandConstant(CP));
3319     break;
3320   }
3321   case ISD::FSUB: {
3322     EVT VT = Node->getValueType(0);
3323     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3324         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3325       const SDNodeFlags Flags = Node->getFlags();
3326       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3327       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3328       Results.push_back(Tmp1);
3329     }
3330     break;
3331   }
3332   case ISD::SUB: {
3333     EVT VT = Node->getValueType(0);
3334     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3335            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3336            "Don't know how to expand this subtraction!");
3337     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3338                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3339                                VT));
3340     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3341     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3342     break;
3343   }
3344   case ISD::UREM:
3345   case ISD::SREM: {
3346     EVT VT = Node->getValueType(0);
3347     bool isSigned = Node->getOpcode() == ISD::SREM;
3348     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
3349     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3350     Tmp2 = Node->getOperand(0);
3351     Tmp3 = Node->getOperand(1);
3352     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3353       SDVTList VTs = DAG.getVTList(VT, VT);
3354       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
3355       Results.push_back(Tmp1);
3356     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
3357       // X % Y -> X-X/Y*Y
3358       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
3359       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
3360       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
3361       Results.push_back(Tmp1);
3362     }
3363     break;
3364   }
3365   case ISD::UDIV:
3366   case ISD::SDIV: {
3367     bool isSigned = Node->getOpcode() == ISD::SDIV;
3368     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3369     EVT VT = Node->getValueType(0);
3370     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3371       SDVTList VTs = DAG.getVTList(VT, VT);
3372       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3373                          Node->getOperand(1));
3374       Results.push_back(Tmp1);
3375     }
3376     break;
3377   }
3378   case ISD::MULHU:
3379   case ISD::MULHS: {
3380     unsigned ExpandOpcode =
3381         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3382     EVT VT = Node->getValueType(0);
3383     SDVTList VTs = DAG.getVTList(VT, VT);
3384 
3385     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3386                        Node->getOperand(1));
3387     Results.push_back(Tmp1.getValue(1));
3388     break;
3389   }
3390   case ISD::UMUL_LOHI:
3391   case ISD::SMUL_LOHI: {
3392     SDValue LHS = Node->getOperand(0);
3393     SDValue RHS = Node->getOperand(1);
3394     MVT VT = LHS.getSimpleValueType();
3395     unsigned MULHOpcode =
3396         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3397 
3398     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3399       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3400       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3401       break;
3402     }
3403 
3404     SmallVector<SDValue, 4> Halves;
3405     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3406     assert(TLI.isTypeLegal(HalfType));
3407     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, Node, LHS, RHS, Halves,
3408                            HalfType, DAG,
3409                            TargetLowering::MulExpansionKind::Always)) {
3410       for (unsigned i = 0; i < 2; ++i) {
3411         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3412         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3413         SDValue Shift = DAG.getConstant(
3414             HalfType.getScalarSizeInBits(), dl,
3415             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3416         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3417         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3418       }
3419       break;
3420     }
3421     break;
3422   }
3423   case ISD::MUL: {
3424     EVT VT = Node->getValueType(0);
3425     SDVTList VTs = DAG.getVTList(VT, VT);
3426     // See if multiply or divide can be lowered using two-result operations.
3427     // We just need the low half of the multiply; try both the signed
3428     // and unsigned forms. If the target supports both SMUL_LOHI and
3429     // UMUL_LOHI, form a preference by checking which forms of plain
3430     // MULH it supports.
3431     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3432     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3433     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3434     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3435     unsigned OpToUse = 0;
3436     if (HasSMUL_LOHI && !HasMULHS) {
3437       OpToUse = ISD::SMUL_LOHI;
3438     } else if (HasUMUL_LOHI && !HasMULHU) {
3439       OpToUse = ISD::UMUL_LOHI;
3440     } else if (HasSMUL_LOHI) {
3441       OpToUse = ISD::SMUL_LOHI;
3442     } else if (HasUMUL_LOHI) {
3443       OpToUse = ISD::UMUL_LOHI;
3444     }
3445     if (OpToUse) {
3446       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3447                                     Node->getOperand(1)));
3448       break;
3449     }
3450 
3451     SDValue Lo, Hi;
3452     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3453     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3454         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3455         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3456         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3457         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3458                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3459       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3460       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3461       SDValue Shift =
3462           DAG.getConstant(HalfType.getSizeInBits(), dl,
3463                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3464       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3465       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3466     }
3467     break;
3468   }
3469   case ISD::FSHL:
3470   case ISD::FSHR:
3471     if (TLI.expandFunnelShift(Node, Tmp1, DAG))
3472       Results.push_back(Tmp1);
3473     break;
3474   case ISD::ROTL:
3475   case ISD::ROTR:
3476     if (TLI.expandROT(Node, Tmp1, DAG))
3477       Results.push_back(Tmp1);
3478     break;
3479   case ISD::SADDSAT:
3480   case ISD::UADDSAT:
3481   case ISD::SSUBSAT:
3482   case ISD::USUBSAT:
3483     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3484     break;
3485   case ISD::SMULFIX:
3486   case ISD::SMULFIXSAT:
3487   case ISD::UMULFIX:
3488   case ISD::UMULFIXSAT:
3489     Results.push_back(TLI.expandFixedPointMul(Node, DAG));
3490     break;
3491   case ISD::SDIVFIX:
3492   case ISD::UDIVFIX:
3493     if (SDValue V = TLI.expandFixedPointDiv(Node->getOpcode(), SDLoc(Node),
3494                                             Node->getOperand(0),
3495                                             Node->getOperand(1),
3496                                             Node->getConstantOperandVal(2),
3497                                             DAG)) {
3498       Results.push_back(V);
3499       break;
3500     }
3501     // FIXME: We might want to retry here with a wider type if we fail, if that
3502     // type is legal.
3503     // FIXME: Technically, so long as we only have sdivfixes where BW+Scale is
3504     // <= 128 (which is the case for all of the default Embedded-C types),
3505     // we will only get here with types and scales that we could always expand
3506     // if we were allowed to generate libcalls to division functions of illegal
3507     // type. But we cannot do that.
3508     llvm_unreachable("Cannot expand DIVFIX!");
3509   case ISD::ADDCARRY:
3510   case ISD::SUBCARRY: {
3511     SDValue LHS = Node->getOperand(0);
3512     SDValue RHS = Node->getOperand(1);
3513     SDValue Carry = Node->getOperand(2);
3514 
3515     bool IsAdd = Node->getOpcode() == ISD::ADDCARRY;
3516 
3517     // Initial add of the 2 operands.
3518     unsigned Op = IsAdd ? ISD::ADD : ISD::SUB;
3519     EVT VT = LHS.getValueType();
3520     SDValue Sum = DAG.getNode(Op, dl, VT, LHS, RHS);
3521 
3522     // Initial check for overflow.
3523     EVT CarryType = Node->getValueType(1);
3524     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3525     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3526     SDValue Overflow = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3527 
3528     // Add of the sum and the carry.
3529     SDValue CarryExt =
3530         DAG.getZeroExtendInReg(DAG.getZExtOrTrunc(Carry, dl, VT), dl, MVT::i1);
3531     SDValue Sum2 = DAG.getNode(Op, dl, VT, Sum, CarryExt);
3532 
3533     // Second check for overflow. If we are adding, we can only overflow if the
3534     // initial sum is all 1s ang the carry is set, resulting in a new sum of 0.
3535     // If we are subtracting, we can only overflow if the initial sum is 0 and
3536     // the carry is set, resulting in a new sum of all 1s.
3537     SDValue Zero = DAG.getConstant(0, dl, VT);
3538     SDValue Overflow2 =
3539         IsAdd ? DAG.getSetCC(dl, SetCCType, Sum2, Zero, ISD::SETEQ)
3540               : DAG.getSetCC(dl, SetCCType, Sum, Zero, ISD::SETEQ);
3541     Overflow2 = DAG.getNode(ISD::AND, dl, SetCCType, Overflow2,
3542                             DAG.getZExtOrTrunc(Carry, dl, SetCCType));
3543 
3544     SDValue ResultCarry =
3545         DAG.getNode(ISD::OR, dl, SetCCType, Overflow, Overflow2);
3546 
3547     Results.push_back(Sum2);
3548     Results.push_back(DAG.getBoolExtOrTrunc(ResultCarry, dl, CarryType, VT));
3549     break;
3550   }
3551   case ISD::SADDO:
3552   case ISD::SSUBO: {
3553     SDValue Result, Overflow;
3554     TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
3555     Results.push_back(Result);
3556     Results.push_back(Overflow);
3557     break;
3558   }
3559   case ISD::UADDO:
3560   case ISD::USUBO: {
3561     SDValue Result, Overflow;
3562     TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
3563     Results.push_back(Result);
3564     Results.push_back(Overflow);
3565     break;
3566   }
3567   case ISD::UMULO:
3568   case ISD::SMULO: {
3569     SDValue Result, Overflow;
3570     if (TLI.expandMULO(Node, Result, Overflow, DAG)) {
3571       Results.push_back(Result);
3572       Results.push_back(Overflow);
3573     }
3574     break;
3575   }
3576   case ISD::BUILD_PAIR: {
3577     EVT PairTy = Node->getValueType(0);
3578     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3579     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3580     Tmp2 = DAG.getNode(
3581         ISD::SHL, dl, PairTy, Tmp2,
3582         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3583                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3584     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3585     break;
3586   }
3587   case ISD::SELECT:
3588     Tmp1 = Node->getOperand(0);
3589     Tmp2 = Node->getOperand(1);
3590     Tmp3 = Node->getOperand(2);
3591     if (Tmp1.getOpcode() == ISD::SETCC) {
3592       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3593                              Tmp2, Tmp3,
3594                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3595     } else {
3596       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3597                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3598                              Tmp2, Tmp3, ISD::SETNE);
3599     }
3600     Tmp1->setFlags(Node->getFlags());
3601     Results.push_back(Tmp1);
3602     break;
3603   case ISD::BR_JT: {
3604     SDValue Chain = Node->getOperand(0);
3605     SDValue Table = Node->getOperand(1);
3606     SDValue Index = Node->getOperand(2);
3607 
3608     const DataLayout &TD = DAG.getDataLayout();
3609     EVT PTy = TLI.getPointerTy(TD);
3610 
3611     unsigned EntrySize =
3612       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3613 
3614     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3615     // This transformation needs to be done here since otherwise the MIPS
3616     // backend will end up emitting a three instruction multiply sequence
3617     // instead of a single shift and MSP430 will call a runtime function.
3618     if (llvm::isPowerOf2_32(EntrySize))
3619       Index = DAG.getNode(
3620           ISD::SHL, dl, Index.getValueType(), Index,
3621           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3622     else
3623       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3624                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3625     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3626                                Index, Table);
3627 
3628     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3629     SDValue LD = DAG.getExtLoad(
3630         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3631         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3632     Addr = LD;
3633     if (TLI.isJumpTableRelative()) {
3634       // For PIC, the sequence is:
3635       // BRIND(load(Jumptable + index) + RelocBase)
3636       // RelocBase can be JumpTable, GOT or some sort of global base.
3637       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3638                           TLI.getPICJumpTableRelocBase(Table, DAG));
3639     }
3640 
3641     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3642     Results.push_back(Tmp1);
3643     break;
3644   }
3645   case ISD::BRCOND:
3646     // Expand brcond's setcc into its constituent parts and create a BR_CC
3647     // Node.
3648     Tmp1 = Node->getOperand(0);
3649     Tmp2 = Node->getOperand(1);
3650     if (Tmp2.getOpcode() == ISD::SETCC) {
3651       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3652                          Tmp1, Tmp2.getOperand(2),
3653                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3654                          Node->getOperand(2));
3655     } else {
3656       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3657       if (Tmp2.isUndef() ||
3658           (Tmp2.getOpcode() == ISD::AND &&
3659            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3660            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3661         Tmp3 = Tmp2;
3662       else
3663         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3664                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3665       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3666                          DAG.getCondCode(ISD::SETNE), Tmp3,
3667                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3668                          Node->getOperand(2));
3669     }
3670     Results.push_back(Tmp1);
3671     break;
3672   case ISD::SETCC:
3673   case ISD::STRICT_FSETCC:
3674   case ISD::STRICT_FSETCCS: {
3675     bool IsStrict = Node->getOpcode() != ISD::SETCC;
3676     bool IsSignaling = Node->getOpcode() == ISD::STRICT_FSETCCS;
3677     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
3678     unsigned Offset = IsStrict ? 1 : 0;
3679     Tmp1 = Node->getOperand(0 + Offset);
3680     Tmp2 = Node->getOperand(1 + Offset);
3681     Tmp3 = Node->getOperand(2 + Offset);
3682     bool Legalized =
3683         LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2, Tmp3,
3684                               NeedInvert, dl, Chain, IsSignaling);
3685 
3686     if (Legalized) {
3687       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3688       // condition code, create a new SETCC node.
3689       if (Tmp3.getNode())
3690         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3691                            Tmp1, Tmp2, Tmp3, Node->getFlags());
3692 
3693       // If we expanded the SETCC by inverting the condition code, then wrap
3694       // the existing SETCC in a NOT to restore the intended condition.
3695       if (NeedInvert)
3696         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3697 
3698       Results.push_back(Tmp1);
3699       if (IsStrict)
3700         Results.push_back(Chain);
3701 
3702       break;
3703     }
3704 
3705     // FIXME: It seems Legalized is false iff CCCode is Legal. I don't
3706     // understand if this code is useful for strict nodes.
3707     assert(!IsStrict && "Don't know how to expand for strict nodes.");
3708 
3709     // Otherwise, SETCC for the given comparison type must be completely
3710     // illegal; expand it into a SELECT_CC.
3711     EVT VT = Node->getValueType(0);
3712     int TrueValue;
3713     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3714     case TargetLowering::ZeroOrOneBooleanContent:
3715     case TargetLowering::UndefinedBooleanContent:
3716       TrueValue = 1;
3717       break;
3718     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3719       TrueValue = -1;
3720       break;
3721     }
3722     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3723                        DAG.getConstant(TrueValue, dl, VT),
3724                        DAG.getConstant(0, dl, VT),
3725                        Tmp3);
3726     Tmp1->setFlags(Node->getFlags());
3727     Results.push_back(Tmp1);
3728     break;
3729   }
3730   case ISD::SELECT_CC: {
3731     // TODO: need to add STRICT_SELECT_CC and STRICT_SELECT_CCS
3732     Tmp1 = Node->getOperand(0);   // LHS
3733     Tmp2 = Node->getOperand(1);   // RHS
3734     Tmp3 = Node->getOperand(2);   // True
3735     Tmp4 = Node->getOperand(3);   // False
3736     EVT VT = Node->getValueType(0);
3737     SDValue Chain;
3738     SDValue CC = Node->getOperand(4);
3739     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3740 
3741     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3742       // If the condition code is legal, then we need to expand this
3743       // node using SETCC and SELECT.
3744       EVT CmpVT = Tmp1.getValueType();
3745       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3746              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3747              "expanded.");
3748       EVT CCVT = getSetCCResultType(CmpVT);
3749       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC, Node->getFlags());
3750       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3751       break;
3752     }
3753 
3754     // SELECT_CC is legal, so the condition code must not be.
3755     bool Legalized = false;
3756     // Try to legalize by inverting the condition.  This is for targets that
3757     // might support an ordered version of a condition, but not the unordered
3758     // version (or vice versa).
3759     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp, Tmp1.getValueType());
3760     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3761       // Use the new condition code and swap true and false
3762       Legalized = true;
3763       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3764       Tmp1->setFlags(Node->getFlags());
3765     } else {
3766       // If The inverse is not legal, then try to swap the arguments using
3767       // the inverse condition code.
3768       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3769       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3770         // The swapped inverse condition is legal, so swap true and false,
3771         // lhs and rhs.
3772         Legalized = true;
3773         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3774         Tmp1->setFlags(Node->getFlags());
3775       }
3776     }
3777 
3778     if (!Legalized) {
3779       Legalized = LegalizeSetCCCondCode(getSetCCResultType(Tmp1.getValueType()),
3780                                         Tmp1, Tmp2, CC, NeedInvert, dl, Chain);
3781 
3782       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3783 
3784       // If we expanded the SETCC by inverting the condition code, then swap
3785       // the True/False operands to match.
3786       if (NeedInvert)
3787         std::swap(Tmp3, Tmp4);
3788 
3789       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3790       // condition code, create a new SELECT_CC node.
3791       if (CC.getNode()) {
3792         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3793                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3794       } else {
3795         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3796         CC = DAG.getCondCode(ISD::SETNE);
3797         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3798                            Tmp2, Tmp3, Tmp4, CC);
3799       }
3800       Tmp1->setFlags(Node->getFlags());
3801     }
3802     Results.push_back(Tmp1);
3803     break;
3804   }
3805   case ISD::BR_CC: {
3806     // TODO: need to add STRICT_BR_CC and STRICT_BR_CCS
3807     SDValue Chain;
3808     Tmp1 = Node->getOperand(0);              // Chain
3809     Tmp2 = Node->getOperand(2);              // LHS
3810     Tmp3 = Node->getOperand(3);              // RHS
3811     Tmp4 = Node->getOperand(1);              // CC
3812 
3813     bool Legalized =
3814         LegalizeSetCCCondCode(getSetCCResultType(Tmp2.getValueType()), Tmp2,
3815                               Tmp3, Tmp4, NeedInvert, dl, Chain);
3816     (void)Legalized;
3817     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3818 
3819     assert(!NeedInvert && "Don't know how to invert BR_CC!");
3820 
3821     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3822     // node.
3823     if (Tmp4.getNode()) {
3824       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3825                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3826     } else {
3827       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3828       Tmp4 = DAG.getCondCode(ISD::SETNE);
3829       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3830                          Tmp2, Tmp3, Node->getOperand(4));
3831     }
3832     Results.push_back(Tmp1);
3833     break;
3834   }
3835   case ISD::BUILD_VECTOR:
3836     Results.push_back(ExpandBUILD_VECTOR(Node));
3837     break;
3838   case ISD::SPLAT_VECTOR:
3839     Results.push_back(ExpandSPLAT_VECTOR(Node));
3840     break;
3841   case ISD::SRA:
3842   case ISD::SRL:
3843   case ISD::SHL: {
3844     // Scalarize vector SRA/SRL/SHL.
3845     EVT VT = Node->getValueType(0);
3846     assert(VT.isVector() && "Unable to legalize non-vector shift");
3847     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3848     unsigned NumElem = VT.getVectorNumElements();
3849 
3850     SmallVector<SDValue, 8> Scalars;
3851     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3852       SDValue Ex =
3853           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3854                       Node->getOperand(0), DAG.getVectorIdxConstant(Idx, dl));
3855       SDValue Sh =
3856           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3857                       Node->getOperand(1), DAG.getVectorIdxConstant(Idx, dl));
3858       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3859                                     VT.getScalarType(), Ex, Sh));
3860     }
3861 
3862     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3863     Results.push_back(Result);
3864     break;
3865   }
3866   case ISD::VECREDUCE_FADD:
3867   case ISD::VECREDUCE_FMUL:
3868   case ISD::VECREDUCE_ADD:
3869   case ISD::VECREDUCE_MUL:
3870   case ISD::VECREDUCE_AND:
3871   case ISD::VECREDUCE_OR:
3872   case ISD::VECREDUCE_XOR:
3873   case ISD::VECREDUCE_SMAX:
3874   case ISD::VECREDUCE_SMIN:
3875   case ISD::VECREDUCE_UMAX:
3876   case ISD::VECREDUCE_UMIN:
3877   case ISD::VECREDUCE_FMAX:
3878   case ISD::VECREDUCE_FMIN:
3879     Results.push_back(TLI.expandVecReduce(Node, DAG));
3880     break;
3881   case ISD::GLOBAL_OFFSET_TABLE:
3882   case ISD::GlobalAddress:
3883   case ISD::GlobalTLSAddress:
3884   case ISD::ExternalSymbol:
3885   case ISD::ConstantPool:
3886   case ISD::JumpTable:
3887   case ISD::INTRINSIC_W_CHAIN:
3888   case ISD::INTRINSIC_WO_CHAIN:
3889   case ISD::INTRINSIC_VOID:
3890     // FIXME: Custom lowering for these operations shouldn't return null!
3891     // Return true so that we don't call ConvertNodeToLibcall which also won't
3892     // do anything.
3893     return true;
3894   }
3895 
3896   if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
3897     // FIXME: We were asked to expand a strict floating-point operation,
3898     // but there is currently no expansion implemented that would preserve
3899     // the "strict" properties.  For now, we just fall back to the non-strict
3900     // version if that is legal on the target.  The actual mutation of the
3901     // operation will happen in SelectionDAGISel::DoInstructionSelection.
3902     switch (Node->getOpcode()) {
3903     default:
3904       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3905                                          Node->getValueType(0))
3906           == TargetLowering::Legal)
3907         return true;
3908       break;
3909     case ISD::STRICT_LRINT:
3910     case ISD::STRICT_LLRINT:
3911     case ISD::STRICT_LROUND:
3912     case ISD::STRICT_LLROUND:
3913       // These are registered by the operand type instead of the value
3914       // type. Reflect that here.
3915       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3916                                          Node->getOperand(1).getValueType())
3917           == TargetLowering::Legal)
3918         return true;
3919       break;
3920     }
3921   }
3922 
3923   // Replace the original node with the legalized result.
3924   if (Results.empty()) {
3925     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3926     return false;
3927   }
3928 
3929   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3930   ReplaceNode(Node, Results.data());
3931   return true;
3932 }
3933 
3934 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3935   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3936   SmallVector<SDValue, 8> Results;
3937   SDLoc dl(Node);
3938   // FIXME: Check flags on the node to see if we can use a finite call.
3939   bool CanUseFiniteLibCall = TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath;
3940   unsigned Opc = Node->getOpcode();
3941   switch (Opc) {
3942   case ISD::ATOMIC_FENCE: {
3943     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3944     // FIXME: handle "fence singlethread" more efficiently.
3945     TargetLowering::ArgListTy Args;
3946 
3947     TargetLowering::CallLoweringInfo CLI(DAG);
3948     CLI.setDebugLoc(dl)
3949         .setChain(Node->getOperand(0))
3950         .setLibCallee(
3951             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3952             DAG.getExternalSymbol("__sync_synchronize",
3953                                   TLI.getPointerTy(DAG.getDataLayout())),
3954             std::move(Args));
3955 
3956     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3957 
3958     Results.push_back(CallResult.second);
3959     break;
3960   }
3961   // By default, atomic intrinsics are marked Legal and lowered. Targets
3962   // which don't support them directly, however, may want libcalls, in which
3963   // case they mark them Expand, and we get here.
3964   case ISD::ATOMIC_SWAP:
3965   case ISD::ATOMIC_LOAD_ADD:
3966   case ISD::ATOMIC_LOAD_SUB:
3967   case ISD::ATOMIC_LOAD_AND:
3968   case ISD::ATOMIC_LOAD_CLR:
3969   case ISD::ATOMIC_LOAD_OR:
3970   case ISD::ATOMIC_LOAD_XOR:
3971   case ISD::ATOMIC_LOAD_NAND:
3972   case ISD::ATOMIC_LOAD_MIN:
3973   case ISD::ATOMIC_LOAD_MAX:
3974   case ISD::ATOMIC_LOAD_UMIN:
3975   case ISD::ATOMIC_LOAD_UMAX:
3976   case ISD::ATOMIC_CMP_SWAP: {
3977     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3978     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
3979     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
3980 
3981     EVT RetVT = Node->getValueType(0);
3982     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
3983     TargetLowering::MakeLibCallOptions CallOptions;
3984     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
3985                                                       Ops, CallOptions,
3986                                                       SDLoc(Node),
3987                                                       Node->getOperand(0));
3988     Results.push_back(Tmp.first);
3989     Results.push_back(Tmp.second);
3990     break;
3991   }
3992   case ISD::TRAP: {
3993     // If this operation is not supported, lower it to 'abort()' call
3994     TargetLowering::ArgListTy Args;
3995     TargetLowering::CallLoweringInfo CLI(DAG);
3996     CLI.setDebugLoc(dl)
3997         .setChain(Node->getOperand(0))
3998         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3999                       DAG.getExternalSymbol(
4000                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
4001                       std::move(Args));
4002     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
4003 
4004     Results.push_back(CallResult.second);
4005     break;
4006   }
4007   case ISD::FMINNUM:
4008   case ISD::STRICT_FMINNUM:
4009     ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
4010                     RTLIB::FMIN_F80, RTLIB::FMIN_F128,
4011                     RTLIB::FMIN_PPCF128, Results);
4012     break;
4013   case ISD::FMAXNUM:
4014   case ISD::STRICT_FMAXNUM:
4015     ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
4016                     RTLIB::FMAX_F80, RTLIB::FMAX_F128,
4017                     RTLIB::FMAX_PPCF128, Results);
4018     break;
4019   case ISD::FSQRT:
4020   case ISD::STRICT_FSQRT:
4021     ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
4022                     RTLIB::SQRT_F80, RTLIB::SQRT_F128,
4023                     RTLIB::SQRT_PPCF128, Results);
4024     break;
4025   case ISD::FCBRT:
4026     ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
4027                     RTLIB::CBRT_F80, RTLIB::CBRT_F128,
4028                     RTLIB::CBRT_PPCF128, Results);
4029     break;
4030   case ISD::FSIN:
4031   case ISD::STRICT_FSIN:
4032     ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
4033                     RTLIB::SIN_F80, RTLIB::SIN_F128,
4034                     RTLIB::SIN_PPCF128, Results);
4035     break;
4036   case ISD::FCOS:
4037   case ISD::STRICT_FCOS:
4038     ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
4039                     RTLIB::COS_F80, RTLIB::COS_F128,
4040                     RTLIB::COS_PPCF128, Results);
4041     break;
4042   case ISD::FSINCOS:
4043     // Expand into sincos libcall.
4044     ExpandSinCosLibCall(Node, Results);
4045     break;
4046   case ISD::FLOG:
4047   case ISD::STRICT_FLOG:
4048     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log_finite))
4049       ExpandFPLibCall(Node, RTLIB::LOG_FINITE_F32,
4050                       RTLIB::LOG_FINITE_F64,
4051                       RTLIB::LOG_FINITE_F80,
4052                       RTLIB::LOG_FINITE_F128,
4053                       RTLIB::LOG_FINITE_PPCF128, Results);
4054     else
4055       ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
4056                       RTLIB::LOG_F80, RTLIB::LOG_F128,
4057                       RTLIB::LOG_PPCF128, Results);
4058     break;
4059   case ISD::FLOG2:
4060   case ISD::STRICT_FLOG2:
4061     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log2_finite))
4062       ExpandFPLibCall(Node, RTLIB::LOG2_FINITE_F32,
4063                       RTLIB::LOG2_FINITE_F64,
4064                       RTLIB::LOG2_FINITE_F80,
4065                       RTLIB::LOG2_FINITE_F128,
4066                       RTLIB::LOG2_FINITE_PPCF128, Results);
4067     else
4068       ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
4069                       RTLIB::LOG2_F80, RTLIB::LOG2_F128,
4070                       RTLIB::LOG2_PPCF128, Results);
4071     break;
4072   case ISD::FLOG10:
4073   case ISD::STRICT_FLOG10:
4074     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log10_finite))
4075       ExpandFPLibCall(Node, RTLIB::LOG10_FINITE_F32,
4076                       RTLIB::LOG10_FINITE_F64,
4077                       RTLIB::LOG10_FINITE_F80,
4078                       RTLIB::LOG10_FINITE_F128,
4079                       RTLIB::LOG10_FINITE_PPCF128, Results);
4080     else
4081       ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
4082                       RTLIB::LOG10_F80, RTLIB::LOG10_F128,
4083                       RTLIB::LOG10_PPCF128, Results);
4084     break;
4085   case ISD::FEXP:
4086   case ISD::STRICT_FEXP:
4087     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp_finite))
4088       ExpandFPLibCall(Node, RTLIB::EXP_FINITE_F32,
4089                       RTLIB::EXP_FINITE_F64,
4090                       RTLIB::EXP_FINITE_F80,
4091                       RTLIB::EXP_FINITE_F128,
4092                       RTLIB::EXP_FINITE_PPCF128, Results);
4093     else
4094       ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
4095                       RTLIB::EXP_F80, RTLIB::EXP_F128,
4096                       RTLIB::EXP_PPCF128, Results);
4097     break;
4098   case ISD::FEXP2:
4099   case ISD::STRICT_FEXP2:
4100     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp2_finite))
4101       ExpandFPLibCall(Node, RTLIB::EXP2_FINITE_F32,
4102                       RTLIB::EXP2_FINITE_F64,
4103                       RTLIB::EXP2_FINITE_F80,
4104                       RTLIB::EXP2_FINITE_F128,
4105                       RTLIB::EXP2_FINITE_PPCF128, Results);
4106     else
4107       ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
4108                       RTLIB::EXP2_F80, RTLIB::EXP2_F128,
4109                       RTLIB::EXP2_PPCF128, Results);
4110     break;
4111   case ISD::FTRUNC:
4112   case ISD::STRICT_FTRUNC:
4113     ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4114                     RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4115                     RTLIB::TRUNC_PPCF128, Results);
4116     break;
4117   case ISD::FFLOOR:
4118   case ISD::STRICT_FFLOOR:
4119     ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4120                     RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4121                     RTLIB::FLOOR_PPCF128, Results);
4122     break;
4123   case ISD::FCEIL:
4124   case ISD::STRICT_FCEIL:
4125     ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4126                     RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4127                     RTLIB::CEIL_PPCF128, Results);
4128     break;
4129   case ISD::FRINT:
4130   case ISD::STRICT_FRINT:
4131     ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4132                     RTLIB::RINT_F80, RTLIB::RINT_F128,
4133                     RTLIB::RINT_PPCF128, Results);
4134     break;
4135   case ISD::FNEARBYINT:
4136   case ISD::STRICT_FNEARBYINT:
4137     ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4138                     RTLIB::NEARBYINT_F64,
4139                     RTLIB::NEARBYINT_F80,
4140                     RTLIB::NEARBYINT_F128,
4141                     RTLIB::NEARBYINT_PPCF128, Results);
4142     break;
4143   case ISD::FROUND:
4144   case ISD::STRICT_FROUND:
4145     ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4146                     RTLIB::ROUND_F64,
4147                     RTLIB::ROUND_F80,
4148                     RTLIB::ROUND_F128,
4149                     RTLIB::ROUND_PPCF128, Results);
4150     break;
4151   case ISD::FPOWI:
4152   case ISD::STRICT_FPOWI: {
4153     RTLIB::Libcall LC;
4154     switch (Node->getSimpleValueType(0).SimpleTy) {
4155     default: llvm_unreachable("Unexpected request for libcall!");
4156     case MVT::f32: LC = RTLIB::POWI_F32; break;
4157     case MVT::f64: LC = RTLIB::POWI_F64; break;
4158     case MVT::f80: LC = RTLIB::POWI_F80; break;
4159     case MVT::f128: LC = RTLIB::POWI_F128; break;
4160     case MVT::ppcf128: LC = RTLIB::POWI_PPCF128; break;
4161     }
4162     if (!TLI.getLibcallName(LC)) {
4163       // Some targets don't have a powi libcall; use pow instead.
4164       SDValue Exponent = DAG.getNode(ISD::SINT_TO_FP, SDLoc(Node),
4165                                      Node->getValueType(0),
4166                                      Node->getOperand(1));
4167       Results.push_back(DAG.getNode(ISD::FPOW, SDLoc(Node),
4168                                     Node->getValueType(0), Node->getOperand(0),
4169                                     Exponent));
4170       break;
4171     }
4172     ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
4173                     RTLIB::POWI_F80, RTLIB::POWI_F128,
4174                     RTLIB::POWI_PPCF128, Results);
4175     break;
4176   }
4177   case ISD::FPOW:
4178   case ISD::STRICT_FPOW:
4179     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_pow_finite))
4180       ExpandFPLibCall(Node, RTLIB::POW_FINITE_F32,
4181                       RTLIB::POW_FINITE_F64,
4182                       RTLIB::POW_FINITE_F80,
4183                       RTLIB::POW_FINITE_F128,
4184                       RTLIB::POW_FINITE_PPCF128, Results);
4185     else
4186       ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
4187                       RTLIB::POW_F80, RTLIB::POW_F128,
4188                       RTLIB::POW_PPCF128, Results);
4189     break;
4190   case ISD::LROUND:
4191   case ISD::STRICT_LROUND:
4192     ExpandArgFPLibCall(Node, RTLIB::LROUND_F32,
4193                        RTLIB::LROUND_F64, RTLIB::LROUND_F80,
4194                        RTLIB::LROUND_F128,
4195                        RTLIB::LROUND_PPCF128, Results);
4196     break;
4197   case ISD::LLROUND:
4198   case ISD::STRICT_LLROUND:
4199     ExpandArgFPLibCall(Node, RTLIB::LLROUND_F32,
4200                        RTLIB::LLROUND_F64, RTLIB::LLROUND_F80,
4201                        RTLIB::LLROUND_F128,
4202                        RTLIB::LLROUND_PPCF128, Results);
4203     break;
4204   case ISD::LRINT:
4205   case ISD::STRICT_LRINT:
4206     ExpandArgFPLibCall(Node, RTLIB::LRINT_F32,
4207                        RTLIB::LRINT_F64, RTLIB::LRINT_F80,
4208                        RTLIB::LRINT_F128,
4209                        RTLIB::LRINT_PPCF128, Results);
4210     break;
4211   case ISD::LLRINT:
4212   case ISD::STRICT_LLRINT:
4213     ExpandArgFPLibCall(Node, RTLIB::LLRINT_F32,
4214                        RTLIB::LLRINT_F64, RTLIB::LLRINT_F80,
4215                        RTLIB::LLRINT_F128,
4216                        RTLIB::LLRINT_PPCF128, Results);
4217     break;
4218   case ISD::FDIV:
4219   case ISD::STRICT_FDIV:
4220     ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4221                     RTLIB::DIV_F80, RTLIB::DIV_F128,
4222                     RTLIB::DIV_PPCF128, Results);
4223     break;
4224   case ISD::FREM:
4225   case ISD::STRICT_FREM:
4226     ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4227                     RTLIB::REM_F80, RTLIB::REM_F128,
4228                     RTLIB::REM_PPCF128, Results);
4229     break;
4230   case ISD::FMA:
4231   case ISD::STRICT_FMA:
4232     ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4233                     RTLIB::FMA_F80, RTLIB::FMA_F128,
4234                     RTLIB::FMA_PPCF128, Results);
4235     break;
4236   case ISD::FADD:
4237   case ISD::STRICT_FADD:
4238     ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4239                     RTLIB::ADD_F80, RTLIB::ADD_F128,
4240                     RTLIB::ADD_PPCF128, Results);
4241     break;
4242   case ISD::FMUL:
4243   case ISD::STRICT_FMUL:
4244     ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4245                     RTLIB::MUL_F80, RTLIB::MUL_F128,
4246                     RTLIB::MUL_PPCF128, Results);
4247     break;
4248   case ISD::FP16_TO_FP:
4249     if (Node->getValueType(0) == MVT::f32) {
4250       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4251     }
4252     break;
4253   case ISD::STRICT_FP16_TO_FP: {
4254     if (Node->getValueType(0) == MVT::f32) {
4255       TargetLowering::MakeLibCallOptions CallOptions;
4256       std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(
4257           DAG, RTLIB::FPEXT_F16_F32, MVT::f32, Node->getOperand(1), CallOptions,
4258           SDLoc(Node), Node->getOperand(0));
4259       Results.push_back(Tmp.first);
4260       Results.push_back(Tmp.second);
4261     }
4262     break;
4263   }
4264   case ISD::FP_TO_FP16: {
4265     RTLIB::Libcall LC =
4266         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4267     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4268     Results.push_back(ExpandLibCall(LC, Node, false));
4269     break;
4270   }
4271   case ISD::STRICT_FP_TO_FP16: {
4272     RTLIB::Libcall LC =
4273         RTLIB::getFPROUND(Node->getOperand(1).getValueType(), MVT::f16);
4274     assert(LC != RTLIB::UNKNOWN_LIBCALL &&
4275            "Unable to expand strict_fp_to_fp16");
4276     TargetLowering::MakeLibCallOptions CallOptions;
4277     std::pair<SDValue, SDValue> Tmp =
4278         TLI.makeLibCall(DAG, LC, Node->getValueType(0), Node->getOperand(1),
4279                         CallOptions, SDLoc(Node), Node->getOperand(0));
4280     Results.push_back(Tmp.first);
4281     Results.push_back(Tmp.second);
4282     break;
4283   }
4284   case ISD::FSUB:
4285   case ISD::STRICT_FSUB:
4286     ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4287                     RTLIB::SUB_F80, RTLIB::SUB_F128,
4288                     RTLIB::SUB_PPCF128, Results);
4289     break;
4290   case ISD::SREM:
4291     Results.push_back(ExpandIntLibCall(Node, true,
4292                                        RTLIB::SREM_I8,
4293                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4294                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4295     break;
4296   case ISD::UREM:
4297     Results.push_back(ExpandIntLibCall(Node, false,
4298                                        RTLIB::UREM_I8,
4299                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4300                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4301     break;
4302   case ISD::SDIV:
4303     Results.push_back(ExpandIntLibCall(Node, true,
4304                                        RTLIB::SDIV_I8,
4305                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4306                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4307     break;
4308   case ISD::UDIV:
4309     Results.push_back(ExpandIntLibCall(Node, false,
4310                                        RTLIB::UDIV_I8,
4311                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4312                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4313     break;
4314   case ISD::SDIVREM:
4315   case ISD::UDIVREM:
4316     // Expand into divrem libcall
4317     ExpandDivRemLibCall(Node, Results);
4318     break;
4319   case ISD::MUL:
4320     Results.push_back(ExpandIntLibCall(Node, false,
4321                                        RTLIB::MUL_I8,
4322                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4323                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4324     break;
4325   case ISD::CTLZ_ZERO_UNDEF:
4326     switch (Node->getSimpleValueType(0).SimpleTy) {
4327     default:
4328       llvm_unreachable("LibCall explicitly requested, but not available");
4329     case MVT::i32:
4330       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4331       break;
4332     case MVT::i64:
4333       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4334       break;
4335     case MVT::i128:
4336       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4337       break;
4338     }
4339     break;
4340   }
4341 
4342   // Replace the original node with the legalized result.
4343   if (!Results.empty()) {
4344     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4345     ReplaceNode(Node, Results.data());
4346   } else
4347     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4348 }
4349 
4350 // Determine the vector type to use in place of an original scalar element when
4351 // promoting equally sized vectors.
4352 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4353                                         MVT EltVT, MVT NewEltVT) {
4354   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4355   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4356   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4357   return MidVT;
4358 }
4359 
4360 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4361   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4362   SmallVector<SDValue, 8> Results;
4363   MVT OVT = Node->getSimpleValueType(0);
4364   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4365       Node->getOpcode() == ISD::SINT_TO_FP ||
4366       Node->getOpcode() == ISD::SETCC ||
4367       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4368       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4369     OVT = Node->getOperand(0).getSimpleValueType();
4370   }
4371   if (Node->getOpcode() == ISD::STRICT_UINT_TO_FP ||
4372       Node->getOpcode() == ISD::STRICT_SINT_TO_FP)
4373     OVT = Node->getOperand(1).getSimpleValueType();
4374   if (Node->getOpcode() == ISD::BR_CC)
4375     OVT = Node->getOperand(2).getSimpleValueType();
4376   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4377   SDLoc dl(Node);
4378   SDValue Tmp1, Tmp2, Tmp3;
4379   switch (Node->getOpcode()) {
4380   case ISD::CTTZ:
4381   case ISD::CTTZ_ZERO_UNDEF:
4382   case ISD::CTLZ:
4383   case ISD::CTLZ_ZERO_UNDEF:
4384   case ISD::CTPOP:
4385     // Zero extend the argument unless its cttz, then use any_extend.
4386     if (Node->getOpcode() == ISD::CTTZ ||
4387         Node->getOpcode() == ISD::CTTZ_ZERO_UNDEF)
4388       Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4389     else
4390       Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4391 
4392     if (Node->getOpcode() == ISD::CTTZ) {
4393       // The count is the same in the promoted type except if the original
4394       // value was zero.  This can be handled by setting the bit just off
4395       // the top of the original type.
4396       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4397                                         OVT.getSizeInBits());
4398       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4399                          DAG.getConstant(TopBit, dl, NVT));
4400     }
4401     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4402     // already the correct result.
4403     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4404     if (Node->getOpcode() == ISD::CTLZ ||
4405         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4406       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4407       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4408                           DAG.getConstant(NVT.getSizeInBits() -
4409                                           OVT.getSizeInBits(), dl, NVT));
4410     }
4411     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4412     break;
4413   case ISD::BITREVERSE:
4414   case ISD::BSWAP: {
4415     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4416     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4417     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4418     Tmp1 = DAG.getNode(
4419         ISD::SRL, dl, NVT, Tmp1,
4420         DAG.getConstant(DiffBits, dl,
4421                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4422 
4423     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4424     break;
4425   }
4426   case ISD::FP_TO_UINT:
4427   case ISD::STRICT_FP_TO_UINT:
4428   case ISD::FP_TO_SINT:
4429   case ISD::STRICT_FP_TO_SINT:
4430     PromoteLegalFP_TO_INT(Node, dl, Results);
4431     break;
4432   case ISD::UINT_TO_FP:
4433   case ISD::STRICT_UINT_TO_FP:
4434   case ISD::SINT_TO_FP:
4435   case ISD::STRICT_SINT_TO_FP:
4436     PromoteLegalINT_TO_FP(Node, dl, Results);
4437     break;
4438   case ISD::VAARG: {
4439     SDValue Chain = Node->getOperand(0); // Get the chain.
4440     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4441 
4442     unsigned TruncOp;
4443     if (OVT.isVector()) {
4444       TruncOp = ISD::BITCAST;
4445     } else {
4446       assert(OVT.isInteger()
4447         && "VAARG promotion is supported only for vectors or integer types");
4448       TruncOp = ISD::TRUNCATE;
4449     }
4450 
4451     // Perform the larger operation, then convert back
4452     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4453              Node->getConstantOperandVal(3));
4454     Chain = Tmp1.getValue(1);
4455 
4456     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4457 
4458     // Modified the chain result - switch anything that used the old chain to
4459     // use the new one.
4460     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4461     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4462     if (UpdatedNodes) {
4463       UpdatedNodes->insert(Tmp2.getNode());
4464       UpdatedNodes->insert(Chain.getNode());
4465     }
4466     ReplacedNode(Node);
4467     break;
4468   }
4469   case ISD::MUL:
4470   case ISD::SDIV:
4471   case ISD::SREM:
4472   case ISD::UDIV:
4473   case ISD::UREM:
4474   case ISD::AND:
4475   case ISD::OR:
4476   case ISD::XOR: {
4477     unsigned ExtOp, TruncOp;
4478     if (OVT.isVector()) {
4479       ExtOp   = ISD::BITCAST;
4480       TruncOp = ISD::BITCAST;
4481     } else {
4482       assert(OVT.isInteger() && "Cannot promote logic operation");
4483 
4484       switch (Node->getOpcode()) {
4485       default:
4486         ExtOp = ISD::ANY_EXTEND;
4487         break;
4488       case ISD::SDIV:
4489       case ISD::SREM:
4490         ExtOp = ISD::SIGN_EXTEND;
4491         break;
4492       case ISD::UDIV:
4493       case ISD::UREM:
4494         ExtOp = ISD::ZERO_EXTEND;
4495         break;
4496       }
4497       TruncOp = ISD::TRUNCATE;
4498     }
4499     // Promote each of the values to the new type.
4500     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4501     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4502     // Perform the larger operation, then convert back
4503     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4504     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4505     break;
4506   }
4507   case ISD::UMUL_LOHI:
4508   case ISD::SMUL_LOHI: {
4509     // Promote to a multiply in a wider integer type.
4510     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4511                                                          : ISD::SIGN_EXTEND;
4512     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4513     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4514     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4515 
4516     auto &DL = DAG.getDataLayout();
4517     unsigned OriginalSize = OVT.getScalarSizeInBits();
4518     Tmp2 = DAG.getNode(
4519         ISD::SRL, dl, NVT, Tmp1,
4520         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4521     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4522     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4523     break;
4524   }
4525   case ISD::SELECT: {
4526     unsigned ExtOp, TruncOp;
4527     if (Node->getValueType(0).isVector() ||
4528         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4529       ExtOp   = ISD::BITCAST;
4530       TruncOp = ISD::BITCAST;
4531     } else if (Node->getValueType(0).isInteger()) {
4532       ExtOp   = ISD::ANY_EXTEND;
4533       TruncOp = ISD::TRUNCATE;
4534     } else {
4535       ExtOp   = ISD::FP_EXTEND;
4536       TruncOp = ISD::FP_ROUND;
4537     }
4538     Tmp1 = Node->getOperand(0);
4539     // Promote each of the values to the new type.
4540     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4541     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4542     // Perform the larger operation, then round down.
4543     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4544     Tmp1->setFlags(Node->getFlags());
4545     if (TruncOp != ISD::FP_ROUND)
4546       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4547     else
4548       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4549                          DAG.getIntPtrConstant(0, dl));
4550     Results.push_back(Tmp1);
4551     break;
4552   }
4553   case ISD::VECTOR_SHUFFLE: {
4554     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4555 
4556     // Cast the two input vectors.
4557     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4558     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4559 
4560     // Convert the shuffle mask to the right # elements.
4561     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4562     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4563     Results.push_back(Tmp1);
4564     break;
4565   }
4566   case ISD::SETCC: {
4567     unsigned ExtOp = ISD::FP_EXTEND;
4568     if (NVT.isInteger()) {
4569       ISD::CondCode CCCode =
4570         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4571       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4572     }
4573     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4574     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4575     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0), Tmp1,
4576                                   Tmp2, Node->getOperand(2), Node->getFlags()));
4577     break;
4578   }
4579   case ISD::BR_CC: {
4580     unsigned ExtOp = ISD::FP_EXTEND;
4581     if (NVT.isInteger()) {
4582       ISD::CondCode CCCode =
4583         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4584       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4585     }
4586     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4587     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4588     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4589                                   Node->getOperand(0), Node->getOperand(1),
4590                                   Tmp1, Tmp2, Node->getOperand(4)));
4591     break;
4592   }
4593   case ISD::FADD:
4594   case ISD::FSUB:
4595   case ISD::FMUL:
4596   case ISD::FDIV:
4597   case ISD::FREM:
4598   case ISD::FMINNUM:
4599   case ISD::FMAXNUM:
4600   case ISD::FPOW:
4601     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4602     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4603     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4604                        Node->getFlags());
4605     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4606                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4607     break;
4608   case ISD::STRICT_FREM:
4609   case ISD::STRICT_FPOW:
4610     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4611                        {Node->getOperand(0), Node->getOperand(1)});
4612     Tmp2 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4613                        {Node->getOperand(0), Node->getOperand(2)});
4614     Tmp3 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Tmp1.getValue(1),
4615                        Tmp2.getValue(1));
4616     Tmp1 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4617                        {Tmp3, Tmp1, Tmp2});
4618     Tmp1 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4619                        {Tmp1.getValue(1), Tmp1, DAG.getIntPtrConstant(0, dl)});
4620     Results.push_back(Tmp1);
4621     Results.push_back(Tmp1.getValue(1));
4622     break;
4623   case ISD::FMA:
4624     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4625     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4626     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4627     Results.push_back(
4628         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4629                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4630                     DAG.getIntPtrConstant(0, dl)));
4631     break;
4632   case ISD::FCOPYSIGN:
4633   case ISD::FPOWI: {
4634     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4635     Tmp2 = Node->getOperand(1);
4636     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4637 
4638     // fcopysign doesn't change anything but the sign bit, so
4639     //   (fp_round (fcopysign (fpext a), b))
4640     // is as precise as
4641     //   (fp_round (fpext a))
4642     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4643     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4644     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4645                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4646     break;
4647   }
4648   case ISD::FFLOOR:
4649   case ISD::FCEIL:
4650   case ISD::FRINT:
4651   case ISD::FNEARBYINT:
4652   case ISD::FROUND:
4653   case ISD::FTRUNC:
4654   case ISD::FNEG:
4655   case ISD::FSQRT:
4656   case ISD::FSIN:
4657   case ISD::FCOS:
4658   case ISD::FLOG:
4659   case ISD::FLOG2:
4660   case ISD::FLOG10:
4661   case ISD::FABS:
4662   case ISD::FEXP:
4663   case ISD::FEXP2:
4664     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4665     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4666     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4667                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4668     break;
4669   case ISD::STRICT_FFLOOR:
4670   case ISD::STRICT_FCEIL:
4671   case ISD::STRICT_FSIN:
4672   case ISD::STRICT_FCOS:
4673   case ISD::STRICT_FLOG:
4674   case ISD::STRICT_FLOG10:
4675   case ISD::STRICT_FEXP:
4676     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4677                        {Node->getOperand(0), Node->getOperand(1)});
4678     Tmp2 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4679                        {Tmp1.getValue(1), Tmp1});
4680     Tmp3 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4681                        {Tmp2.getValue(1), Tmp2, DAG.getIntPtrConstant(0, dl)});
4682     Results.push_back(Tmp3);
4683     Results.push_back(Tmp3.getValue(1));
4684     break;
4685   case ISD::BUILD_VECTOR: {
4686     MVT EltVT = OVT.getVectorElementType();
4687     MVT NewEltVT = NVT.getVectorElementType();
4688 
4689     // Handle bitcasts to a different vector type with the same total bit size
4690     //
4691     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4692     //  =>
4693     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4694 
4695     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4696            "Invalid promote type for build_vector");
4697     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4698 
4699     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4700 
4701     SmallVector<SDValue, 8> NewOps;
4702     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4703       SDValue Op = Node->getOperand(I);
4704       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4705     }
4706 
4707     SDLoc SL(Node);
4708     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4709     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4710     Results.push_back(CvtVec);
4711     break;
4712   }
4713   case ISD::EXTRACT_VECTOR_ELT: {
4714     MVT EltVT = OVT.getVectorElementType();
4715     MVT NewEltVT = NVT.getVectorElementType();
4716 
4717     // Handle bitcasts to a different vector type with the same total bit size.
4718     //
4719     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4720     //  =>
4721     //  v4i32:castx = bitcast x:v2i64
4722     //
4723     // i64 = bitcast
4724     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4725     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4726     //
4727 
4728     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4729            "Invalid promote type for extract_vector_elt");
4730     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4731 
4732     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4733     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4734 
4735     SDValue Idx = Node->getOperand(1);
4736     EVT IdxVT = Idx.getValueType();
4737     SDLoc SL(Node);
4738     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4739     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4740 
4741     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4742 
4743     SmallVector<SDValue, 8> NewOps;
4744     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4745       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4746       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4747 
4748       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4749                                 CastVec, TmpIdx);
4750       NewOps.push_back(Elt);
4751     }
4752 
4753     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4754     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4755     break;
4756   }
4757   case ISD::INSERT_VECTOR_ELT: {
4758     MVT EltVT = OVT.getVectorElementType();
4759     MVT NewEltVT = NVT.getVectorElementType();
4760 
4761     // Handle bitcasts to a different vector type with the same total bit size
4762     //
4763     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4764     //  =>
4765     //  v4i32:castx = bitcast x:v2i64
4766     //  v2i32:casty = bitcast y:i64
4767     //
4768     // v2i64 = bitcast
4769     //   (v4i32 insert_vector_elt
4770     //       (v4i32 insert_vector_elt v4i32:castx,
4771     //                                (extract_vector_elt casty, 0), 2 * z),
4772     //        (extract_vector_elt casty, 1), (2 * z + 1))
4773 
4774     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4775            "Invalid promote type for insert_vector_elt");
4776     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4777 
4778     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4779     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4780 
4781     SDValue Val = Node->getOperand(1);
4782     SDValue Idx = Node->getOperand(2);
4783     EVT IdxVT = Idx.getValueType();
4784     SDLoc SL(Node);
4785 
4786     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4787     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4788 
4789     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4790     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4791 
4792     SDValue NewVec = CastVec;
4793     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4794       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4795       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4796 
4797       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4798                                 CastVal, IdxOffset);
4799 
4800       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4801                            NewVec, Elt, InEltIdx);
4802     }
4803 
4804     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4805     break;
4806   }
4807   case ISD::SCALAR_TO_VECTOR: {
4808     MVT EltVT = OVT.getVectorElementType();
4809     MVT NewEltVT = NVT.getVectorElementType();
4810 
4811     // Handle bitcasts to different vector type with the same total bit size.
4812     //
4813     // e.g. v2i64 = scalar_to_vector x:i64
4814     //   =>
4815     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4816     //
4817 
4818     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4819     SDValue Val = Node->getOperand(0);
4820     SDLoc SL(Node);
4821 
4822     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4823     SDValue Undef = DAG.getUNDEF(MidVT);
4824 
4825     SmallVector<SDValue, 8> NewElts;
4826     NewElts.push_back(CastVal);
4827     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4828       NewElts.push_back(Undef);
4829 
4830     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4831     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4832     Results.push_back(CvtVec);
4833     break;
4834   }
4835   case ISD::ATOMIC_SWAP: {
4836     AtomicSDNode *AM = cast<AtomicSDNode>(Node);
4837     SDLoc SL(Node);
4838     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NVT, AM->getVal());
4839     assert(NVT.getSizeInBits() == OVT.getSizeInBits() &&
4840            "unexpected promotion type");
4841     assert(AM->getMemoryVT().getSizeInBits() == NVT.getSizeInBits() &&
4842            "unexpected atomic_swap with illegal type");
4843 
4844     SDValue NewAtomic
4845       = DAG.getAtomic(ISD::ATOMIC_SWAP, SL, NVT,
4846                       DAG.getVTList(NVT, MVT::Other),
4847                       { AM->getChain(), AM->getBasePtr(), CastVal },
4848                       AM->getMemOperand());
4849     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewAtomic));
4850     Results.push_back(NewAtomic.getValue(1));
4851     break;
4852   }
4853   }
4854 
4855   // Replace the original node with the legalized result.
4856   if (!Results.empty()) {
4857     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4858     ReplaceNode(Node, Results.data());
4859   } else
4860     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4861 }
4862 
4863 /// This is the entry point for the file.
4864 void SelectionDAG::Legalize() {
4865   AssignTopologicalOrder();
4866 
4867   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4868   // Use a delete listener to remove nodes which were deleted during
4869   // legalization from LegalizeNodes. This is needed to handle the situation
4870   // where a new node is allocated by the object pool to the same address of a
4871   // previously deleted node.
4872   DAGNodeDeletedListener DeleteListener(
4873       *this,
4874       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4875 
4876   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4877 
4878   // Visit all the nodes. We start in topological order, so that we see
4879   // nodes with their original operands intact. Legalization can produce
4880   // new nodes which may themselves need to be legalized. Iterate until all
4881   // nodes have been legalized.
4882   while (true) {
4883     bool AnyLegalized = false;
4884     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4885       --NI;
4886 
4887       SDNode *N = &*NI;
4888       if (N->use_empty() && N != getRoot().getNode()) {
4889         ++NI;
4890         DeleteNode(N);
4891         continue;
4892       }
4893 
4894       if (LegalizedNodes.insert(N).second) {
4895         AnyLegalized = true;
4896         Legalizer.LegalizeOp(N);
4897 
4898         if (N->use_empty() && N != getRoot().getNode()) {
4899           ++NI;
4900           DeleteNode(N);
4901         }
4902       }
4903     }
4904     if (!AnyLegalized)
4905       break;
4906 
4907   }
4908 
4909   // Remove dead nodes now.
4910   RemoveDeadNodes();
4911 }
4912 
4913 bool SelectionDAG::LegalizeOp(SDNode *N,
4914                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4915   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4916   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4917 
4918   // Directly insert the node in question, and legalize it. This will recurse
4919   // as needed through operands.
4920   LegalizedNodes.insert(N);
4921   Legalizer.LegalizeOp(N);
4922 
4923   return LegalizedNodes.count(N);
4924 }
4925