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