1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the SelectionDAG::Legalize method.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/APFloat.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/SetVector.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/SmallSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/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/MachineValueType.h"
26 #include "llvm/CodeGen/RuntimeLibcalls.h"
27 #include "llvm/CodeGen/SelectionDAG.h"
28 #include "llvm/CodeGen/SelectionDAGNodes.h"
29 #include "llvm/CodeGen/TargetFrameLowering.h"
30 #include "llvm/CodeGen/TargetLowering.h"
31 #include "llvm/CodeGen/TargetSubtargetInfo.h"
32 #include "llvm/CodeGen/ValueTypes.h"
33 #include "llvm/IR/CallingConv.h"
34 #include "llvm/IR/Constants.h"
35 #include "llvm/IR/DataLayout.h"
36 #include "llvm/IR/DerivedTypes.h"
37 #include "llvm/IR/Function.h"
38 #include "llvm/IR/Metadata.h"
39 #include "llvm/IR/Type.h"
40 #include "llvm/Support/Casting.h"
41 #include "llvm/Support/Compiler.h"
42 #include "llvm/Support/Debug.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/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   /// \brief 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   /// \brief 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   /// \brief 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);
138 
139   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
140   SDValue ExpandLibCall(RTLIB::Libcall LC, EVT RetVT, const SDValue *Ops,
141                         unsigned NumOps, bool isSigned, const SDLoc &dl);
142 
143   std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
144                                                  SDNode *Node, bool isSigned);
145   SDValue ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
146                           RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
147                           RTLIB::Libcall Call_F128,
148                           RTLIB::Libcall Call_PPCF128);
149   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
150                            RTLIB::Libcall Call_I8,
151                            RTLIB::Libcall Call_I16,
152                            RTLIB::Libcall Call_I32,
153                            RTLIB::Libcall Call_I64,
154                            RTLIB::Libcall Call_I128);
155   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
156   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
157 
158   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
159                            const SDLoc &dl);
160   SDValue ExpandBUILD_VECTOR(SDNode *Node);
161   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
162   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
163                                 SmallVectorImpl<SDValue> &Results);
164   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
165                          SDValue Value) const;
166   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
167                           SDValue NewIntValue) const;
168   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
169   SDValue ExpandFABS(SDNode *Node) const;
170   SDValue ExpandLegalINT_TO_FP(bool isSigned, SDValue LegalOp, EVT DestVT,
171                                const SDLoc &dl);
172   SDValue PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT, bool isSigned,
173                                 const SDLoc &dl);
174   SDValue PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT, bool isSigned,
175                                 const SDLoc &dl);
176 
177   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
178   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
179   SDValue ExpandBitCount(unsigned Opc, SDValue Op, const SDLoc &dl);
180 
181   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
182   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
183   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
184 
185   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
186   SDValue ExpandConstant(ConstantSDNode *CP);
187 
188   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
189   bool ExpandNode(SDNode *Node);
190   void ConvertNodeToLibcall(SDNode *Node);
191   void PromoteNode(SDNode *Node);
192 
193 public:
194   // Node replacement helpers
195 
196   void ReplacedNode(SDNode *N) {
197     LegalizedNodes.erase(N);
198     if (UpdatedNodes)
199       UpdatedNodes->insert(N);
200   }
201 
202   void ReplaceNode(SDNode *Old, SDNode *New) {
203     DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
204           dbgs() << "     with:      "; New->dump(&DAG));
205 
206     assert(Old->getNumValues() == New->getNumValues() &&
207            "Replacing one node with another that produces a different number "
208            "of values!");
209     DAG.ReplaceAllUsesWith(Old, New);
210     if (UpdatedNodes)
211       UpdatedNodes->insert(New);
212     ReplacedNode(Old);
213   }
214 
215   void ReplaceNode(SDValue Old, SDValue New) {
216     DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
217           dbgs() << "     with:      "; New->dump(&DAG));
218 
219     DAG.ReplaceAllUsesWith(Old, New);
220     if (UpdatedNodes)
221       UpdatedNodes->insert(New.getNode());
222     ReplacedNode(Old.getNode());
223   }
224 
225   void ReplaceNode(SDNode *Old, const SDValue *New) {
226     DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
227 
228     DAG.ReplaceAllUsesWith(Old, New);
229     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
230       DEBUG(dbgs() << (i == 0 ? "     with:      "
231                               : "      and:      ");
232             New[i]->dump(&DAG));
233       if (UpdatedNodes)
234         UpdatedNodes->insert(New[i].getNode());
235     }
236     ReplacedNode(Old);
237   }
238 };
239 
240 } // end anonymous namespace
241 
242 /// Return a vector shuffle operation which
243 /// performs the same shuffe in terms of order or result bytes, but on a type
244 /// whose vector element type is narrower than the original shuffle type.
245 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
246 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
247     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
248     ArrayRef<int> Mask) const {
249   unsigned NumMaskElts = VT.getVectorNumElements();
250   unsigned NumDestElts = NVT.getVectorNumElements();
251   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
252 
253   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
254 
255   if (NumEltsGrowth == 1)
256     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
257 
258   SmallVector<int, 8> NewMask;
259   for (unsigned i = 0; i != NumMaskElts; ++i) {
260     int Idx = Mask[i];
261     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
262       if (Idx < 0)
263         NewMask.push_back(-1);
264       else
265         NewMask.push_back(Idx * NumEltsGrowth + j);
266     }
267   }
268   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
269   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
270   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
271 }
272 
273 /// Expands the ConstantFP node to an integer constant or
274 /// a load from the constant pool.
275 SDValue
276 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
277   bool Extend = false;
278   SDLoc dl(CFP);
279 
280   // If a FP immediate is precise when represented as a float and if the
281   // target can do an extending load from float to double, we put it into
282   // the constant pool as a float, even if it's is statically typed as a
283   // double.  This shrinks FP constants and canonicalizes them for targets where
284   // an FP extending load is the same cost as a normal load (such as on the x87
285   // fp stack or PPC FP unit).
286   EVT VT = CFP->getValueType(0);
287   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
288   if (!UseCP) {
289     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
290     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
291                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
292   }
293 
294   APFloat APF = CFP->getValueAPF();
295   EVT OrigVT = VT;
296   EVT SVT = VT;
297 
298   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
299   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
300   if (!APF.isSignaling()) {
301     while (SVT != MVT::f32 && SVT != MVT::f16) {
302       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
303       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
304           // Only do this if the target has a native EXTLOAD instruction from
305           // smaller type.
306           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
307           TLI.ShouldShrinkFPConstant(OrigVT)) {
308         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
309         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
310         VT = SVT;
311         Extend = true;
312       }
313     }
314   }
315 
316   SDValue CPIdx =
317       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
318   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
319   if (Extend) {
320     SDValue Result = DAG.getExtLoad(
321         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
322         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
323         Alignment);
324     return Result;
325   }
326   SDValue Result = DAG.getLoad(
327       OrigVT, dl, DAG.getEntryNode(), CPIdx,
328       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
329   return Result;
330 }
331 
332 /// Expands the Constant node to a load from the constant pool.
333 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
334   SDLoc dl(CP);
335   EVT VT = CP->getValueType(0);
336   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
337                                       TLI.getPointerTy(DAG.getDataLayout()));
338   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
339   SDValue Result = DAG.getLoad(
340       VT, dl, DAG.getEntryNode(), CPIdx,
341       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
342   return Result;
343 }
344 
345 /// Some target cannot handle a variable insertion index for the
346 /// INSERT_VECTOR_ELT instruction.  In this case, it
347 /// is necessary to spill the vector being inserted into to memory, perform
348 /// the insert there, and then read the result back.
349 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
350                                                              SDValue Val,
351                                                              SDValue Idx,
352                                                              const SDLoc &dl) {
353   SDValue Tmp1 = Vec;
354   SDValue Tmp2 = Val;
355   SDValue Tmp3 = Idx;
356 
357   // If the target doesn't support this, we have to spill the input vector
358   // to a temporary stack slot, update the element, then reload it.  This is
359   // badness.  We could also load the value into a vector register (either
360   // with a "move to register" or "extload into register" instruction, then
361   // permute it into place, if the idx is a constant and if the idx is
362   // supported by the target.
363   EVT VT    = Tmp1.getValueType();
364   EVT EltVT = VT.getVectorElementType();
365   SDValue StackPtr = DAG.CreateStackTemporary(VT);
366 
367   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
368 
369   // Store the vector.
370   SDValue Ch = DAG.getStore(
371       DAG.getEntryNode(), dl, Tmp1, StackPtr,
372       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
373 
374   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
375 
376   // Store the scalar value.
377   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT);
378   // Load the updated vector.
379   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
380                                                DAG.getMachineFunction(), SPFI));
381 }
382 
383 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
384                                                       SDValue Idx,
385                                                       const SDLoc &dl) {
386   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
387     // SCALAR_TO_VECTOR requires that the type of the value being inserted
388     // match the element type of the vector being created, except for
389     // integers in which case the inserted value can be over width.
390     EVT EltVT = Vec.getValueType().getVectorElementType();
391     if (Val.getValueType() == EltVT ||
392         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
393       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
394                                   Vec.getValueType(), Val);
395 
396       unsigned NumElts = Vec.getValueType().getVectorNumElements();
397       // We generate a shuffle of InVec and ScVec, so the shuffle mask
398       // should be 0,1,2,3,4,5... with the appropriate element replaced with
399       // elt 0 of the RHS.
400       SmallVector<int, 8> ShufOps;
401       for (unsigned i = 0; i != NumElts; ++i)
402         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
403 
404       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
405     }
406   }
407   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
408 }
409 
410 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
411   DEBUG(dbgs() << "Optimizing float store operations\n");
412   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
413   // FIXME: We shouldn't do this for TargetConstantFP's.
414   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
415   // to phase ordering between legalized code and the dag combiner.  This
416   // probably means that we need to integrate dag combiner and legalizer
417   // together.
418   // We generally can't do this one for long doubles.
419   SDValue Chain = ST->getChain();
420   SDValue Ptr = ST->getBasePtr();
421   unsigned Alignment = ST->getAlignment();
422   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
423   AAMDNodes AAInfo = ST->getAAInfo();
424   SDLoc dl(ST);
425   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
426     if (CFP->getValueType(0) == MVT::f32 &&
427         TLI.isTypeLegal(MVT::i32)) {
428       SDValue Con = DAG.getConstant(CFP->getValueAPF().
429                                       bitcastToAPInt().zextOrTrunc(32),
430                                     SDLoc(CFP), MVT::i32);
431       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(), Alignment,
432                           MMOFlags, AAInfo);
433     }
434 
435     if (CFP->getValueType(0) == MVT::f64) {
436       // If this target supports 64-bit registers, do a single 64-bit store.
437       if (TLI.isTypeLegal(MVT::i64)) {
438         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
439                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
440         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
441                             Alignment, MMOFlags, AAInfo);
442       }
443 
444       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
445         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
446         // stores.  If the target supports neither 32- nor 64-bits, this
447         // xform is certainly not worth it.
448         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
449         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
450         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
451         if (DAG.getDataLayout().isBigEndian())
452           std::swap(Lo, Hi);
453 
454         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), Alignment,
455                           MMOFlags, AAInfo);
456         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
457                           DAG.getConstant(4, dl, Ptr.getValueType()));
458         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
459                           ST->getPointerInfo().getWithOffset(4),
460                           MinAlign(Alignment, 4U), MMOFlags, AAInfo);
461 
462         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
463       }
464     }
465   }
466   return SDValue(nullptr, 0);
467 }
468 
469 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
470   StoreSDNode *ST = cast<StoreSDNode>(Node);
471   SDValue Chain = ST->getChain();
472   SDValue Ptr = ST->getBasePtr();
473   SDLoc dl(Node);
474 
475   unsigned Alignment = ST->getAlignment();
476   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
477   AAMDNodes AAInfo = ST->getAAInfo();
478 
479   if (!ST->isTruncatingStore()) {
480     DEBUG(dbgs() << "Legalizing store operation\n");
481     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
482       ReplaceNode(ST, OptStore);
483       return;
484     }
485 
486     SDValue Value = ST->getValue();
487     MVT VT = Value.getSimpleValueType();
488     switch (TLI.getOperationAction(ISD::STORE, VT)) {
489     default: llvm_unreachable("This action is not supported yet!");
490     case TargetLowering::Legal: {
491       // If this is an unaligned store and the target doesn't support it,
492       // expand it.
493       EVT MemVT = ST->getMemoryVT();
494       unsigned AS = ST->getAddressSpace();
495       unsigned Align = ST->getAlignment();
496       const DataLayout &DL = DAG.getDataLayout();
497       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
498         DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
499         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
500         ReplaceNode(SDValue(ST, 0), Result);
501       } else
502         DEBUG(dbgs() << "Legal store\n");
503       break;
504     }
505     case TargetLowering::Custom: {
506       DEBUG(dbgs() << "Trying custom lowering\n");
507       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
508       if (Res && Res != SDValue(Node, 0))
509         ReplaceNode(SDValue(Node, 0), Res);
510       return;
511     }
512     case TargetLowering::Promote: {
513       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
514       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
515              "Can only promote stores to same size type");
516       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
517       SDValue Result =
518           DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
519                        Alignment, MMOFlags, AAInfo);
520       ReplaceNode(SDValue(Node, 0), Result);
521       break;
522     }
523     }
524     return;
525   }
526 
527   DEBUG(dbgs() << "Legalizing truncating store operations\n");
528   SDValue Value = ST->getValue();
529   EVT StVT = ST->getMemoryVT();
530   unsigned StWidth = StVT.getSizeInBits();
531   auto &DL = DAG.getDataLayout();
532 
533   if (StWidth != StVT.getStoreSizeInBits()) {
534     // Promote to a byte-sized store with upper bits zero if not
535     // storing an integral number of bytes.  For example, promote
536     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
537     EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
538                                 StVT.getStoreSizeInBits());
539     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
540     SDValue Result =
541         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
542                           Alignment, MMOFlags, AAInfo);
543     ReplaceNode(SDValue(Node, 0), Result);
544   } else if (StWidth & (StWidth - 1)) {
545     // If not storing a power-of-2 number of bits, expand as two stores.
546     assert(!StVT.isVector() && "Unsupported truncstore!");
547     unsigned RoundWidth = 1 << Log2_32(StWidth);
548     assert(RoundWidth < StWidth);
549     unsigned ExtraWidth = StWidth - RoundWidth;
550     assert(ExtraWidth < RoundWidth);
551     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
552            "Store size not an integral number of bytes!");
553     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
554     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
555     SDValue Lo, Hi;
556     unsigned IncrementSize;
557 
558     if (DL.isLittleEndian()) {
559       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
560       // Store the bottom RoundWidth bits.
561       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
562                              RoundVT, Alignment, MMOFlags, AAInfo);
563 
564       // Store the remaining ExtraWidth bits.
565       IncrementSize = RoundWidth / 8;
566       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
567                         DAG.getConstant(IncrementSize, dl,
568                                         Ptr.getValueType()));
569       Hi = DAG.getNode(
570           ISD::SRL, dl, Value.getValueType(), Value,
571           DAG.getConstant(RoundWidth, dl,
572                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
573       Hi = DAG.getTruncStore(
574           Chain, dl, Hi, Ptr,
575           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
576           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
577     } else {
578       // Big endian - avoid unaligned stores.
579       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
580       // Store the top RoundWidth bits.
581       Hi = DAG.getNode(
582           ISD::SRL, dl, Value.getValueType(), Value,
583           DAG.getConstant(ExtraWidth, dl,
584                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
585       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
586                              RoundVT, Alignment, MMOFlags, AAInfo);
587 
588       // Store the remaining ExtraWidth bits.
589       IncrementSize = RoundWidth / 8;
590       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
591                         DAG.getConstant(IncrementSize, dl,
592                                         Ptr.getValueType()));
593       Lo = DAG.getTruncStore(
594           Chain, dl, Value, Ptr,
595           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
596           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
597     }
598 
599     // The order of the stores doesn't matter.
600     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
601     ReplaceNode(SDValue(Node, 0), Result);
602   } else {
603     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
604     default: llvm_unreachable("This action is not supported yet!");
605     case TargetLowering::Legal: {
606       EVT MemVT = ST->getMemoryVT();
607       unsigned AS = ST->getAddressSpace();
608       unsigned Align = ST->getAlignment();
609       // If this is an unaligned store and the target doesn't support it,
610       // expand it.
611       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
612         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
613         ReplaceNode(SDValue(ST, 0), Result);
614       }
615       break;
616     }
617     case TargetLowering::Custom: {
618       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
619       if (Res && Res != SDValue(Node, 0))
620         ReplaceNode(SDValue(Node, 0), Res);
621       return;
622     }
623     case TargetLowering::Expand:
624       assert(!StVT.isVector() &&
625              "Vector Stores are handled in LegalizeVectorOps");
626 
627       SDValue Result;
628 
629       // TRUNCSTORE:i16 i32 -> STORE i16
630       if (TLI.isTypeLegal(StVT)) {
631         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
632         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
633                               Alignment, MMOFlags, AAInfo);
634       } else {
635         // The in-memory type isn't legal. Truncate to the type it would promote
636         // to, and then do a truncstore.
637         Value = DAG.getNode(ISD::TRUNCATE, dl,
638                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
639                             Value);
640         Result = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
641                                    StVT, Alignment, MMOFlags, AAInfo);
642       }
643 
644       ReplaceNode(SDValue(Node, 0), Result);
645       break;
646     }
647   }
648 }
649 
650 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
651   LoadSDNode *LD = cast<LoadSDNode>(Node);
652   SDValue Chain = LD->getChain();  // The chain.
653   SDValue Ptr = LD->getBasePtr();  // The base pointer.
654   SDValue Value;                   // The value returned by the load op.
655   SDLoc dl(Node);
656 
657   ISD::LoadExtType ExtType = LD->getExtensionType();
658   if (ExtType == ISD::NON_EXTLOAD) {
659     DEBUG(dbgs() << "Legalizing non-extending load operation\n");
660     MVT VT = Node->getSimpleValueType(0);
661     SDValue RVal = SDValue(Node, 0);
662     SDValue RChain = SDValue(Node, 1);
663 
664     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
665     default: llvm_unreachable("This action is not supported yet!");
666     case TargetLowering::Legal: {
667       EVT MemVT = LD->getMemoryVT();
668       unsigned AS = LD->getAddressSpace();
669       unsigned Align = LD->getAlignment();
670       const DataLayout &DL = DAG.getDataLayout();
671       // If this is an unaligned load and the target doesn't support it,
672       // expand it.
673       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
674         std::tie(RVal, RChain) =  TLI.expandUnalignedLoad(LD, DAG);
675       }
676       break;
677     }
678     case TargetLowering::Custom:
679       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
680         RVal = Res;
681         RChain = Res.getValue(1);
682       }
683       break;
684 
685     case TargetLowering::Promote: {
686       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
687       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
688              "Can only promote loads to same size type");
689 
690       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
691       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
692       RChain = Res.getValue(1);
693       break;
694     }
695     }
696     if (RChain.getNode() != Node) {
697       assert(RVal.getNode() != Node && "Load must be completely replaced");
698       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
699       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
700       if (UpdatedNodes) {
701         UpdatedNodes->insert(RVal.getNode());
702         UpdatedNodes->insert(RChain.getNode());
703       }
704       ReplacedNode(Node);
705     }
706     return;
707   }
708 
709   DEBUG(dbgs() << "Legalizing extending load operation\n");
710   EVT SrcVT = LD->getMemoryVT();
711   unsigned SrcWidth = SrcVT.getSizeInBits();
712   unsigned Alignment = LD->getAlignment();
713   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
714   AAMDNodes AAInfo = LD->getAAInfo();
715 
716   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
717       // Some targets pretend to have an i1 loading operation, and actually
718       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
719       // bits are guaranteed to be zero; it helps the optimizers understand
720       // that these bits are zero.  It is also useful for EXTLOAD, since it
721       // tells the optimizers that those bits are undefined.  It would be
722       // nice to have an effective generic way of getting these benefits...
723       // Until such a way is found, don't insist on promoting i1 here.
724       (SrcVT != MVT::i1 ||
725        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
726          TargetLowering::Promote)) {
727     // Promote to a byte-sized load if not loading an integral number of
728     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
729     unsigned NewWidth = SrcVT.getStoreSizeInBits();
730     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
731     SDValue Ch;
732 
733     // The extra bits are guaranteed to be zero, since we stored them that
734     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
735 
736     ISD::LoadExtType NewExtType =
737       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
738 
739     SDValue Result =
740         DAG.getExtLoad(NewExtType, dl, Node->getValueType(0), Chain, Ptr,
741                        LD->getPointerInfo(), NVT, Alignment, MMOFlags, AAInfo);
742 
743     Ch = Result.getValue(1); // The chain.
744 
745     if (ExtType == ISD::SEXTLOAD)
746       // Having the top bits zero doesn't help when sign extending.
747       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
748                            Result.getValueType(),
749                            Result, DAG.getValueType(SrcVT));
750     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
751       // All the top bits are guaranteed to be zero - inform the optimizers.
752       Result = DAG.getNode(ISD::AssertZext, dl,
753                            Result.getValueType(), Result,
754                            DAG.getValueType(SrcVT));
755 
756     Value = Result;
757     Chain = Ch;
758   } else if (SrcWidth & (SrcWidth - 1)) {
759     // If not loading a power-of-2 number of bits, expand as two loads.
760     assert(!SrcVT.isVector() && "Unsupported extload!");
761     unsigned RoundWidth = 1 << Log2_32(SrcWidth);
762     assert(RoundWidth < SrcWidth);
763     unsigned ExtraWidth = SrcWidth - RoundWidth;
764     assert(ExtraWidth < RoundWidth);
765     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
766            "Load size not an integral number of bytes!");
767     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
768     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
769     SDValue Lo, Hi, Ch;
770     unsigned IncrementSize;
771     auto &DL = DAG.getDataLayout();
772 
773     if (DL.isLittleEndian()) {
774       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
775       // Load the bottom RoundWidth bits.
776       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
777                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
778                           AAInfo);
779 
780       // Load the remaining ExtraWidth bits.
781       IncrementSize = RoundWidth / 8;
782       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
783                          DAG.getConstant(IncrementSize, dl,
784                                          Ptr.getValueType()));
785       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
786                           LD->getPointerInfo().getWithOffset(IncrementSize),
787                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
788                           AAInfo);
789 
790       // Build a factor node to remember that this load is independent of
791       // the other one.
792       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
793                        Hi.getValue(1));
794 
795       // Move the top bits to the right place.
796       Hi = DAG.getNode(
797           ISD::SHL, dl, Hi.getValueType(), Hi,
798           DAG.getConstant(RoundWidth, dl,
799                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
800 
801       // Join the hi and lo parts.
802       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
803     } else {
804       // Big endian - avoid unaligned loads.
805       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
806       // Load the top RoundWidth bits.
807       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
808                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
809                           AAInfo);
810 
811       // Load the remaining ExtraWidth bits.
812       IncrementSize = RoundWidth / 8;
813       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
814                          DAG.getConstant(IncrementSize, dl,
815                                          Ptr.getValueType()));
816       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
817                           LD->getPointerInfo().getWithOffset(IncrementSize),
818                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
819                           AAInfo);
820 
821       // Build a factor node to remember that this load is independent of
822       // the other one.
823       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
824                        Hi.getValue(1));
825 
826       // Move the top bits to the right place.
827       Hi = DAG.getNode(
828           ISD::SHL, dl, Hi.getValueType(), Hi,
829           DAG.getConstant(ExtraWidth, dl,
830                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
831 
832       // Join the hi and lo parts.
833       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
834     }
835 
836     Chain = Ch;
837   } else {
838     bool isCustom = false;
839     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
840                                  SrcVT.getSimpleVT())) {
841     default: llvm_unreachable("This action is not supported yet!");
842     case TargetLowering::Custom:
843       isCustom = true;
844       LLVM_FALLTHROUGH;
845     case TargetLowering::Legal:
846       Value = SDValue(Node, 0);
847       Chain = SDValue(Node, 1);
848 
849       if (isCustom) {
850         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
851           Value = Res;
852           Chain = Res.getValue(1);
853         }
854       } else {
855         // If this is an unaligned load and the target doesn't support it,
856         // expand it.
857         EVT MemVT = LD->getMemoryVT();
858         unsigned AS = LD->getAddressSpace();
859         unsigned Align = LD->getAlignment();
860         const DataLayout &DL = DAG.getDataLayout();
861         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
862           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
863         }
864       }
865       break;
866 
867     case TargetLowering::Expand: {
868       EVT DestVT = Node->getValueType(0);
869       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
870         // If the source type is not legal, see if there is a legal extload to
871         // an intermediate type that we can then extend further.
872         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
873         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
874             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
875           // If we are loading a legal type, this is a non-extload followed by a
876           // full extend.
877           ISD::LoadExtType MidExtType =
878               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
879 
880           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
881                                         SrcVT, LD->getMemOperand());
882           unsigned ExtendOp =
883               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
884           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
885           Chain = Load.getValue(1);
886           break;
887         }
888 
889         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
890         // normal undefined upper bits behavior to allow using an in-reg extend
891         // with the illegal FP type, so load as an integer and do the
892         // from-integer conversion.
893         if (SrcVT.getScalarType() == MVT::f16) {
894           EVT ISrcVT = SrcVT.changeTypeToInteger();
895           EVT IDestVT = DestVT.changeTypeToInteger();
896           EVT LoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
897 
898           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, LoadVT,
899                                           Chain, Ptr, ISrcVT,
900                                           LD->getMemOperand());
901           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
902           Chain = Result.getValue(1);
903           break;
904         }
905       }
906 
907       assert(!SrcVT.isVector() &&
908              "Vector Loads are handled in LegalizeVectorOps");
909 
910       // FIXME: This does not work for vectors on most targets.  Sign-
911       // and zero-extend operations are currently folded into extending
912       // loads, whether they are legal or not, and then we end up here
913       // without any support for legalizing them.
914       assert(ExtType != ISD::EXTLOAD &&
915              "EXTLOAD should always be supported!");
916       // Turn the unsupported load into an EXTLOAD followed by an
917       // explicit zero/sign extend inreg.
918       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
919                                       Node->getValueType(0),
920                                       Chain, Ptr, SrcVT,
921                                       LD->getMemOperand());
922       SDValue ValRes;
923       if (ExtType == ISD::SEXTLOAD)
924         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
925                              Result.getValueType(),
926                              Result, DAG.getValueType(SrcVT));
927       else
928         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
929       Value = ValRes;
930       Chain = Result.getValue(1);
931       break;
932     }
933     }
934   }
935 
936   // Since loads produce two values, make sure to remember that we legalized
937   // both of them.
938   if (Chain.getNode() != Node) {
939     assert(Value.getNode() != Node && "Load must be completely replaced");
940     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
941     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
942     if (UpdatedNodes) {
943       UpdatedNodes->insert(Value.getNode());
944       UpdatedNodes->insert(Chain.getNode());
945     }
946     ReplacedNode(Node);
947   }
948 }
949 
950 static TargetLowering::LegalizeAction
951 getStrictFPOpcodeAction(const TargetLowering &TLI, unsigned Opcode, EVT VT) {
952   unsigned EqOpc;
953   switch (Opcode) {
954     default: llvm_unreachable("Unexpected FP pseudo-opcode");
955     case ISD::STRICT_FSQRT: EqOpc = ISD::FSQRT; break;
956     case ISD::STRICT_FPOW: EqOpc = ISD::FPOW; break;
957     case ISD::STRICT_FPOWI: EqOpc = ISD::FPOWI; break;
958     case ISD::STRICT_FMA: EqOpc = ISD::FMA; break;
959     case ISD::STRICT_FSIN: EqOpc = ISD::FSIN; break;
960     case ISD::STRICT_FCOS: EqOpc = ISD::FCOS; break;
961     case ISD::STRICT_FEXP: EqOpc = ISD::FEXP; break;
962     case ISD::STRICT_FEXP2: EqOpc = ISD::FEXP2; break;
963     case ISD::STRICT_FLOG: EqOpc = ISD::FLOG; break;
964     case ISD::STRICT_FLOG10: EqOpc = ISD::FLOG10; break;
965     case ISD::STRICT_FLOG2: EqOpc = ISD::FLOG2; break;
966     case ISD::STRICT_FRINT: EqOpc = ISD::FRINT; break;
967     case ISD::STRICT_FNEARBYINT: EqOpc = ISD::FNEARBYINT; break;
968   }
969 
970   auto Action = TLI.getOperationAction(EqOpc, VT);
971 
972   // We don't currently handle Custom or Promote for strict FP pseudo-ops.
973   // For now, we just expand for those cases.
974   if (Action != TargetLowering::Legal)
975     Action = TargetLowering::Expand;
976 
977   return Action;
978 }
979 
980 /// Return a legal replacement for the given operation, with all legal operands.
981 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
982   DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
983 
984   // Allow illegal target nodes and illegal registers.
985   if (Node->getOpcode() == ISD::TargetConstant ||
986       Node->getOpcode() == ISD::Register)
987     return;
988 
989 #ifndef NDEBUG
990   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
991     assert((TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
992               TargetLowering::TypeLegal ||
993             TLI.isTypeLegal(Node->getValueType(i))) &&
994            "Unexpected illegal type!");
995 
996   for (const SDValue &Op : Node->op_values())
997     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
998               TargetLowering::TypeLegal ||
999             TLI.isTypeLegal(Op.getValueType()) ||
1000             Op.getOpcode() == ISD::TargetConstant ||
1001             Op.getOpcode() == ISD::Register) &&
1002             "Unexpected illegal type!");
1003 #endif
1004 
1005   // Figure out the correct action; the way to query this varies by opcode
1006   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
1007   bool SimpleFinishLegalizing = true;
1008   switch (Node->getOpcode()) {
1009   case ISD::INTRINSIC_W_CHAIN:
1010   case ISD::INTRINSIC_WO_CHAIN:
1011   case ISD::INTRINSIC_VOID:
1012   case ISD::STACKSAVE:
1013     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
1014     break;
1015   case ISD::GET_DYNAMIC_AREA_OFFSET:
1016     Action = TLI.getOperationAction(Node->getOpcode(),
1017                                     Node->getValueType(0));
1018     break;
1019   case ISD::VAARG:
1020     Action = TLI.getOperationAction(Node->getOpcode(),
1021                                     Node->getValueType(0));
1022     if (Action != TargetLowering::Promote)
1023       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
1024     break;
1025   case ISD::FP_TO_FP16:
1026   case ISD::SINT_TO_FP:
1027   case ISD::UINT_TO_FP:
1028   case ISD::EXTRACT_VECTOR_ELT:
1029     Action = TLI.getOperationAction(Node->getOpcode(),
1030                                     Node->getOperand(0).getValueType());
1031     break;
1032   case ISD::FP_ROUND_INREG:
1033   case ISD::SIGN_EXTEND_INREG: {
1034     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1035     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1036     break;
1037   }
1038   case ISD::ATOMIC_STORE:
1039     Action = TLI.getOperationAction(Node->getOpcode(),
1040                                     Node->getOperand(2).getValueType());
1041     break;
1042   case ISD::SELECT_CC:
1043   case ISD::SETCC:
1044   case ISD::BR_CC: {
1045     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1046                          Node->getOpcode() == ISD::SETCC ? 2 :
1047                          Node->getOpcode() == ISD::SETCCE ? 3 : 1;
1048     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
1049     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1050     ISD::CondCode CCCode =
1051         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1052     Action = TLI.getCondCodeAction(CCCode, OpVT);
1053     if (Action == TargetLowering::Legal) {
1054       if (Node->getOpcode() == ISD::SELECT_CC)
1055         Action = TLI.getOperationAction(Node->getOpcode(),
1056                                         Node->getValueType(0));
1057       else
1058         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1059     }
1060     break;
1061   }
1062   case ISD::LOAD:
1063   case ISD::STORE:
1064     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1065     // STORE expects the unlegalized operand in some cases.
1066     SimpleFinishLegalizing = false;
1067     break;
1068   case ISD::CALLSEQ_START:
1069   case ISD::CALLSEQ_END:
1070     // FIXME: This shouldn't be necessary.  These nodes have special properties
1071     // dealing with the recursive nature of legalization.  Removing this
1072     // special case should be done as part of making LegalizeDAG non-recursive.
1073     SimpleFinishLegalizing = false;
1074     break;
1075   case ISD::EXTRACT_ELEMENT:
1076   case ISD::FLT_ROUNDS_:
1077   case ISD::MERGE_VALUES:
1078   case ISD::EH_RETURN:
1079   case ISD::FRAME_TO_ARGS_OFFSET:
1080   case ISD::EH_DWARF_CFA:
1081   case ISD::EH_SJLJ_SETJMP:
1082   case ISD::EH_SJLJ_LONGJMP:
1083   case ISD::EH_SJLJ_SETUP_DISPATCH:
1084     // These operations lie about being legal: when they claim to be legal,
1085     // they should actually be expanded.
1086     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1087     if (Action == TargetLowering::Legal)
1088       Action = TargetLowering::Expand;
1089     break;
1090   case ISD::INIT_TRAMPOLINE:
1091   case ISD::ADJUST_TRAMPOLINE:
1092   case ISD::FRAMEADDR:
1093   case ISD::RETURNADDR:
1094   case ISD::ADDROFRETURNADDR:
1095     // These operations lie about being legal: when they claim to be legal,
1096     // they should actually be custom-lowered.
1097     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1098     if (Action == TargetLowering::Legal)
1099       Action = TargetLowering::Custom;
1100     break;
1101   case ISD::READCYCLECOUNTER:
1102     // READCYCLECOUNTER returns an i64, even if type legalization might have
1103     // expanded that to several smaller types.
1104     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1105     break;
1106   case ISD::READ_REGISTER:
1107   case ISD::WRITE_REGISTER:
1108     // Named register is legal in the DAG, but blocked by register name
1109     // selection if not implemented by target (to chose the correct register)
1110     // They'll be converted to Copy(To/From)Reg.
1111     Action = TargetLowering::Legal;
1112     break;
1113   case ISD::DEBUGTRAP:
1114     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1115     if (Action == TargetLowering::Expand) {
1116       // replace ISD::DEBUGTRAP with ISD::TRAP
1117       SDValue NewVal;
1118       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1119                            Node->getOperand(0));
1120       ReplaceNode(Node, NewVal.getNode());
1121       LegalizeOp(NewVal.getNode());
1122       return;
1123     }
1124     break;
1125   case ISD::STRICT_FSQRT:
1126   case ISD::STRICT_FMA:
1127   case ISD::STRICT_FPOW:
1128   case ISD::STRICT_FPOWI:
1129   case ISD::STRICT_FSIN:
1130   case ISD::STRICT_FCOS:
1131   case ISD::STRICT_FEXP:
1132   case ISD::STRICT_FEXP2:
1133   case ISD::STRICT_FLOG:
1134   case ISD::STRICT_FLOG10:
1135   case ISD::STRICT_FLOG2:
1136   case ISD::STRICT_FRINT:
1137   case ISD::STRICT_FNEARBYINT:
1138     // These pseudo-ops get legalized as if they were their non-strict
1139     // equivalent.  For instance, if ISD::FSQRT is legal then ISD::STRICT_FSQRT
1140     // is also legal, but if ISD::FSQRT requires expansion then so does
1141     // ISD::STRICT_FSQRT.
1142     Action = getStrictFPOpcodeAction(TLI, Node->getOpcode(),
1143                                      Node->getValueType(0));
1144     break;
1145   default:
1146     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1147       Action = TargetLowering::Legal;
1148     } else {
1149       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1150     }
1151     break;
1152   }
1153 
1154   if (SimpleFinishLegalizing) {
1155     SDNode *NewNode = Node;
1156     switch (Node->getOpcode()) {
1157     default: break;
1158     case ISD::SHL:
1159     case ISD::SRL:
1160     case ISD::SRA:
1161     case ISD::ROTL:
1162     case ISD::ROTR: {
1163       // Legalizing shifts/rotates requires adjusting the shift amount
1164       // to the appropriate width.
1165       SDValue Op0 = Node->getOperand(0);
1166       SDValue Op1 = Node->getOperand(1);
1167       if (!Op1.getValueType().isVector()) {
1168         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1169         // The getShiftAmountOperand() may create a new operand node or
1170         // return the existing one. If new operand is created we need
1171         // to update the parent node.
1172         // Do not try to legalize SAO here! It will be automatically legalized
1173         // in the next round.
1174         if (SAO != Op1)
1175           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1176       }
1177     }
1178     break;
1179     case ISD::SRL_PARTS:
1180     case ISD::SRA_PARTS:
1181     case ISD::SHL_PARTS: {
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       SDValue Op2 = Node->getOperand(2);
1187       if (!Op2.getValueType().isVector()) {
1188         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1189         // The getShiftAmountOperand() may create a new operand node or
1190         // return the existing one. If new operand is created we need
1191         // to update the parent node.
1192         if (SAO != Op2)
1193           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1194       }
1195       break;
1196     }
1197     }
1198 
1199     if (NewNode != Node) {
1200       ReplaceNode(Node, NewNode);
1201       Node = NewNode;
1202     }
1203     switch (Action) {
1204     case TargetLowering::Legal:
1205       DEBUG(dbgs() << "Legal node: nothing to do\n");
1206       return;
1207     case TargetLowering::Custom:
1208       DEBUG(dbgs() << "Trying custom legalization\n");
1209       // FIXME: The handling for custom lowering with multiple results is
1210       // a complete mess.
1211       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1212         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1213           return;
1214 
1215         if (Node->getNumValues() == 1) {
1216           DEBUG(dbgs() << "Successfully custom legalized node\n");
1217           // We can just directly replace this node with the lowered value.
1218           ReplaceNode(SDValue(Node, 0), Res);
1219           return;
1220         }
1221 
1222         SmallVector<SDValue, 8> ResultVals;
1223         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1224           ResultVals.push_back(Res.getValue(i));
1225         DEBUG(dbgs() << "Successfully custom legalized node\n");
1226         ReplaceNode(Node, ResultVals.data());
1227         return;
1228       }
1229       DEBUG(dbgs() << "Could not custom legalize node\n");
1230       LLVM_FALLTHROUGH;
1231     case TargetLowering::Expand:
1232       if (ExpandNode(Node))
1233         return;
1234       LLVM_FALLTHROUGH;
1235     case TargetLowering::LibCall:
1236       ConvertNodeToLibcall(Node);
1237       return;
1238     case TargetLowering::Promote:
1239       PromoteNode(Node);
1240       return;
1241     }
1242   }
1243 
1244   switch (Node->getOpcode()) {
1245   default:
1246 #ifndef NDEBUG
1247     dbgs() << "NODE: ";
1248     Node->dump( &DAG);
1249     dbgs() << "\n";
1250 #endif
1251     llvm_unreachable("Do not know how to legalize this operator!");
1252 
1253   case ISD::CALLSEQ_START:
1254   case ISD::CALLSEQ_END:
1255     break;
1256   case ISD::LOAD:
1257     return LegalizeLoadOps(Node);
1258   case ISD::STORE:
1259     return LegalizeStoreOps(Node);
1260   }
1261 }
1262 
1263 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1264   SDValue Vec = Op.getOperand(0);
1265   SDValue Idx = Op.getOperand(1);
1266   SDLoc dl(Op);
1267 
1268   // Before we generate a new store to a temporary stack slot, see if there is
1269   // already one that we can use. There often is because when we scalarize
1270   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1271   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1272   // the vector. If all are expanded here, we don't want one store per vector
1273   // element.
1274 
1275   // Caches for hasPredecessorHelper
1276   SmallPtrSet<const SDNode *, 32> Visited;
1277   SmallVector<const SDNode *, 16> Worklist;
1278   Worklist.push_back(Idx.getNode());
1279   SDValue StackPtr, Ch;
1280   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1281        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1282     SDNode *User = *UI;
1283     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1284       if (ST->isIndexed() || ST->isTruncatingStore() ||
1285           ST->getValue() != Vec)
1286         continue;
1287 
1288       // Make sure that nothing else could have stored into the destination of
1289       // this store.
1290       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1291         continue;
1292 
1293       // If the index is dependent on the store we will introduce a cycle when
1294       // creating the load (the load uses the index, and by replacing the chain
1295       // we will make the index dependent on the load). Also, the store might be
1296       // dependent on the extractelement and introduce a cycle when creating
1297       // the load.
1298       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1299           ST->hasPredecessor(Op.getNode()))
1300         continue;
1301 
1302       StackPtr = ST->getBasePtr();
1303       Ch = SDValue(ST, 0);
1304       break;
1305     }
1306   }
1307 
1308   EVT VecVT = Vec.getValueType();
1309 
1310   if (!Ch.getNode()) {
1311     // Store the value to a temporary stack slot, then LOAD the returned part.
1312     StackPtr = DAG.CreateStackTemporary(VecVT);
1313     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1314                       MachinePointerInfo());
1315   }
1316 
1317   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1318 
1319   SDValue NewLoad;
1320 
1321   if (Op.getValueType().isVector())
1322     NewLoad =
1323         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1324   else
1325     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1326                              MachinePointerInfo(),
1327                              VecVT.getVectorElementType());
1328 
1329   // Replace the chain going out of the store, by the one out of the load.
1330   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1331 
1332   // We introduced a cycle though, so update the loads operands, making sure
1333   // to use the original store's chain as an incoming chain.
1334   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1335                                           NewLoad->op_end());
1336   NewLoadOperands[0] = Ch;
1337   NewLoad =
1338       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1339   return NewLoad;
1340 }
1341 
1342 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1343   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1344 
1345   SDValue Vec  = Op.getOperand(0);
1346   SDValue Part = Op.getOperand(1);
1347   SDValue Idx  = Op.getOperand(2);
1348   SDLoc dl(Op);
1349 
1350   // Store the value to a temporary stack slot, then LOAD the returned part.
1351   EVT VecVT = Vec.getValueType();
1352   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1353   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1354   MachinePointerInfo PtrInfo =
1355       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1356 
1357   // First store the whole vector.
1358   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1359 
1360   // Then store the inserted part.
1361   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1362 
1363   // Store the subvector.
1364   Ch = DAG.getStore(Ch, dl, Part, SubStackPtr, MachinePointerInfo());
1365 
1366   // Finally, load the updated vector.
1367   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1368 }
1369 
1370 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1371   // We can't handle this case efficiently.  Allocate a sufficiently
1372   // aligned object on the stack, store each element into it, then load
1373   // the result as a vector.
1374   // Create the stack frame object.
1375   EVT VT = Node->getValueType(0);
1376   EVT EltVT = VT.getVectorElementType();
1377   SDLoc dl(Node);
1378   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1379   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1380   MachinePointerInfo PtrInfo =
1381       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1382 
1383   // Emit a store of each element to the stack slot.
1384   SmallVector<SDValue, 8> Stores;
1385   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
1386   // Store (in the right endianness) the elements to memory.
1387   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1388     // Ignore undef elements.
1389     if (Node->getOperand(i).isUndef()) continue;
1390 
1391     unsigned Offset = TypeByteSize*i;
1392 
1393     SDValue Idx = DAG.getConstant(Offset, dl, FIPtr.getValueType());
1394     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
1395 
1396     // If the destination vector element type is narrower than the source
1397     // element type, only store the bits necessary.
1398     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
1399       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1400                                          Node->getOperand(i), Idx,
1401                                          PtrInfo.getWithOffset(Offset), EltVT));
1402     } else
1403       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1404                                     Idx, PtrInfo.getWithOffset(Offset)));
1405   }
1406 
1407   SDValue StoreChain;
1408   if (!Stores.empty())    // Not all undef elements?
1409     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1410   else
1411     StoreChain = DAG.getEntryNode();
1412 
1413   // Result is a load from the stack slot.
1414   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1415 }
1416 
1417 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1418 /// containing the sign bit if the target has no integer value capable of
1419 /// holding all bits of the floating-point value.
1420 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1421                                              const SDLoc &DL,
1422                                              SDValue Value) const {
1423   EVT FloatVT = Value.getValueType();
1424   unsigned NumBits = FloatVT.getSizeInBits();
1425   State.FloatVT = FloatVT;
1426   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1427   // Convert to an integer of the same size.
1428   if (TLI.isTypeLegal(IVT)) {
1429     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1430     State.SignMask = APInt::getSignMask(NumBits);
1431     State.SignBit = NumBits - 1;
1432     return;
1433   }
1434 
1435   auto &DataLayout = DAG.getDataLayout();
1436   // Store the float to memory, then load the sign part out as an integer.
1437   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1438   // First create a temporary that is aligned for both the load and store.
1439   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1440   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1441   // Then store the float to it.
1442   State.FloatPtr = StackPtr;
1443   MachineFunction &MF = DAG.getMachineFunction();
1444   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1445   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1446                              State.FloatPointerInfo);
1447 
1448   SDValue IntPtr;
1449   if (DataLayout.isBigEndian()) {
1450     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1451     // Load out a legal integer with the same sign bit as the float.
1452     IntPtr = StackPtr;
1453     State.IntPointerInfo = State.FloatPointerInfo;
1454   } else {
1455     // Advance the pointer so that the loaded byte will contain the sign bit.
1456     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1457     IntPtr = DAG.getNode(ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
1458                       DAG.getConstant(ByteOffset, DL, StackPtr.getValueType()));
1459     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1460                                                              ByteOffset);
1461   }
1462 
1463   State.IntPtr = IntPtr;
1464   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1465                                   State.IntPointerInfo, MVT::i8);
1466   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1467   State.SignBit = 7;
1468 }
1469 
1470 /// Replace the integer value produced by getSignAsIntValue() with a new value
1471 /// and cast the result back to a floating-point type.
1472 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1473                                               const SDLoc &DL,
1474                                               SDValue NewIntValue) const {
1475   if (!State.Chain)
1476     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1477 
1478   // Override the part containing the sign bit in the value stored on the stack.
1479   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1480                                     State.IntPointerInfo, MVT::i8);
1481   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1482                      State.FloatPointerInfo);
1483 }
1484 
1485 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1486   SDLoc DL(Node);
1487   SDValue Mag = Node->getOperand(0);
1488   SDValue Sign = Node->getOperand(1);
1489 
1490   // Get sign bit into an integer value.
1491   FloatSignAsInt SignAsInt;
1492   getSignAsIntValue(SignAsInt, DL, Sign);
1493 
1494   EVT IntVT = SignAsInt.IntValue.getValueType();
1495   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1496   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1497                                 SignMask);
1498 
1499   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1500   EVT FloatVT = Mag.getValueType();
1501   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1502       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1503     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1504     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1505     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1506                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1507     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1508   }
1509 
1510   // Transform Mag value to integer, and clear the sign bit.
1511   FloatSignAsInt MagAsInt;
1512   getSignAsIntValue(MagAsInt, DL, Mag);
1513   EVT MagVT = MagAsInt.IntValue.getValueType();
1514   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1515   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1516                                     ClearSignMask);
1517 
1518   // Get the signbit at the right position for MagAsInt.
1519   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1520   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1521     if (ShiftAmount > 0) {
1522       SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, IntVT);
1523       SignBit = DAG.getNode(ISD::SRL, DL, IntVT, SignBit, ShiftCnst);
1524     } else if (ShiftAmount < 0) {
1525       SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, IntVT);
1526       SignBit = DAG.getNode(ISD::SHL, DL, IntVT, SignBit, ShiftCnst);
1527     }
1528     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1529   } else if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1530     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1531     if (ShiftAmount > 0) {
1532       SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, MagVT);
1533       SignBit = DAG.getNode(ISD::SRL, DL, MagVT, SignBit, ShiftCnst);
1534     } else if (ShiftAmount < 0) {
1535       SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, MagVT);
1536       SignBit = DAG.getNode(ISD::SHL, DL, MagVT, SignBit, ShiftCnst);
1537     }
1538   }
1539 
1540   // Store the part with the modified sign and convert back to float.
1541   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1542   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1543 }
1544 
1545 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1546   SDLoc DL(Node);
1547   SDValue Value = Node->getOperand(0);
1548 
1549   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1550   EVT FloatVT = Value.getValueType();
1551   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1552     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1553     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1554   }
1555 
1556   // Transform value to integer, clear the sign bit and transform back.
1557   FloatSignAsInt ValueAsInt;
1558   getSignAsIntValue(ValueAsInt, DL, Value);
1559   EVT IntVT = ValueAsInt.IntValue.getValueType();
1560   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1561   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1562                                     ClearSignMask);
1563   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1564 }
1565 
1566 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1567                                            SmallVectorImpl<SDValue> &Results) {
1568   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1569   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1570           " not tell us which reg is the stack pointer!");
1571   SDLoc dl(Node);
1572   EVT VT = Node->getValueType(0);
1573   SDValue Tmp1 = SDValue(Node, 0);
1574   SDValue Tmp2 = SDValue(Node, 1);
1575   SDValue Tmp3 = Node->getOperand(2);
1576   SDValue Chain = Tmp1.getOperand(0);
1577 
1578   // Chain the dynamic stack allocation so that it doesn't modify the stack
1579   // pointer when other instructions are using the stack.
1580   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1581 
1582   SDValue Size  = Tmp2.getOperand(1);
1583   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1584   Chain = SP.getValue(1);
1585   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
1586   unsigned StackAlign =
1587       DAG.getSubtarget().getFrameLowering()->getStackAlignment();
1588   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
1589   if (Align > StackAlign)
1590     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1591                        DAG.getConstant(-(uint64_t)Align, dl, VT));
1592   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1593 
1594   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1595                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1596 
1597   Results.push_back(Tmp1);
1598   Results.push_back(Tmp2);
1599 }
1600 
1601 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1602 /// target.
1603 ///
1604 /// If the SETCC has been legalized using AND / OR, then the legalized node
1605 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1606 /// will be set to false.
1607 ///
1608 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1609 /// then the values of LHS and RHS will be swapped, CC will be set to the
1610 /// new condition, and NeedInvert will be set to false.
1611 ///
1612 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1613 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1614 /// will be set to true. The caller must invert the result of the SETCC with
1615 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1616 /// of a true/false result.
1617 ///
1618 /// \returns true if the SetCC has been legalized, false if it hasn't.
1619 bool SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT, SDValue &LHS,
1620                                                  SDValue &RHS, SDValue &CC,
1621                                                  bool &NeedInvert,
1622                                                  const SDLoc &dl) {
1623   MVT OpVT = LHS.getSimpleValueType();
1624   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1625   NeedInvert = false;
1626   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1627   default: llvm_unreachable("Unknown condition code action!");
1628   case TargetLowering::Legal:
1629     // Nothing to do.
1630     break;
1631   case TargetLowering::Expand: {
1632     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1633     if (TLI.isCondCodeLegal(InvCC, OpVT)) {
1634       std::swap(LHS, RHS);
1635       CC = DAG.getCondCode(InvCC);
1636       return true;
1637     }
1638     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1639     unsigned Opc = 0;
1640     switch (CCCode) {
1641     default: llvm_unreachable("Don't know how to expand this condition!");
1642     case ISD::SETO:
1643         assert(TLI.getCondCodeAction(ISD::SETOEQ, OpVT)
1644             == TargetLowering::Legal
1645             && "If SETO is expanded, SETOEQ must be legal!");
1646         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1647     case ISD::SETUO:
1648         assert(TLI.getCondCodeAction(ISD::SETUNE, OpVT)
1649             == TargetLowering::Legal
1650             && "If SETUO is expanded, SETUNE must be legal!");
1651         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1652     case ISD::SETOEQ:
1653     case ISD::SETOGT:
1654     case ISD::SETOGE:
1655     case ISD::SETOLT:
1656     case ISD::SETOLE:
1657     case ISD::SETONE:
1658     case ISD::SETUEQ:
1659     case ISD::SETUNE:
1660     case ISD::SETUGT:
1661     case ISD::SETUGE:
1662     case ISD::SETULT:
1663     case ISD::SETULE:
1664         // If we are floating point, assign and break, otherwise fall through.
1665         if (!OpVT.isInteger()) {
1666           // We can use the 4th bit to tell if we are the unordered
1667           // or ordered version of the opcode.
1668           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1669           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1670           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1671           break;
1672         }
1673         // Fallthrough if we are unsigned integer.
1674         LLVM_FALLTHROUGH;
1675     case ISD::SETLE:
1676     case ISD::SETGT:
1677     case ISD::SETGE:
1678     case ISD::SETLT:
1679       // We only support using the inverted operation, which is computed above
1680       // and not a different manner of supporting expanding these cases.
1681       llvm_unreachable("Don't know how to expand this condition!");
1682     case ISD::SETNE:
1683     case ISD::SETEQ:
1684       // Try inverting the result of the inverse condition.
1685       InvCC = CCCode == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ;
1686       if (TLI.isCondCodeLegal(InvCC, OpVT)) {
1687         CC = DAG.getCondCode(InvCC);
1688         NeedInvert = true;
1689         return true;
1690       }
1691       // If inverting the condition didn't work then we have no means to expand
1692       // the condition.
1693       llvm_unreachable("Don't know how to expand this condition!");
1694     }
1695 
1696     SDValue SetCC1, SetCC2;
1697     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1698       // If we aren't the ordered or unorder operation,
1699       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1700       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
1701       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
1702     } else {
1703       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1704       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1);
1705       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2);
1706     }
1707     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1708     RHS = SDValue();
1709     CC  = SDValue();
1710     return true;
1711   }
1712   }
1713   return false;
1714 }
1715 
1716 /// Emit a store/load combination to the stack.  This stores
1717 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1718 /// a load from the stack slot to DestVT, extending it if needed.
1719 /// The resultant code need not be legal.
1720 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1721                                                EVT DestVT, const SDLoc &dl) {
1722   // Create the stack frame object.
1723   unsigned SrcAlign = DAG.getDataLayout().getPrefTypeAlignment(
1724       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1725   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
1726 
1727   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1728   int SPFI = StackPtrFI->getIndex();
1729   MachinePointerInfo PtrInfo =
1730       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1731 
1732   unsigned SrcSize = SrcOp.getValueSizeInBits();
1733   unsigned SlotSize = SlotVT.getSizeInBits();
1734   unsigned DestSize = DestVT.getSizeInBits();
1735   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1736   unsigned DestAlign = DAG.getDataLayout().getPrefTypeAlignment(DestType);
1737 
1738   // Emit a store to the stack slot.  Use a truncstore if the input value is
1739   // later than DestVT.
1740   SDValue Store;
1741 
1742   if (SrcSize > SlotSize)
1743     Store = DAG.getTruncStore(DAG.getEntryNode(), dl, SrcOp, FIPtr, PtrInfo,
1744                               SlotVT, SrcAlign);
1745   else {
1746     assert(SrcSize == SlotSize && "Invalid store");
1747     Store =
1748         DAG.getStore(DAG.getEntryNode(), dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1749   }
1750 
1751   // Result is a load from the stack slot.
1752   if (SlotSize == DestSize)
1753     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1754 
1755   assert(SlotSize < DestSize && "Unknown extension!");
1756   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1757                         DestAlign);
1758 }
1759 
1760 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1761   SDLoc dl(Node);
1762   // Create a vector sized/aligned stack slot, store the value to element #0,
1763   // then load the whole vector back out.
1764   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1765 
1766   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1767   int SPFI = StackPtrFI->getIndex();
1768 
1769   SDValue Ch = DAG.getTruncStore(
1770       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1771       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1772       Node->getValueType(0).getVectorElementType());
1773   return DAG.getLoad(
1774       Node->getValueType(0), dl, Ch, StackPtr,
1775       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1776 }
1777 
1778 static bool
1779 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1780                      const TargetLowering &TLI, SDValue &Res) {
1781   unsigned NumElems = Node->getNumOperands();
1782   SDLoc dl(Node);
1783   EVT VT = Node->getValueType(0);
1784 
1785   // Try to group the scalars into pairs, shuffle the pairs together, then
1786   // shuffle the pairs of pairs together, etc. until the vector has
1787   // been built. This will work only if all of the necessary shuffle masks
1788   // are legal.
1789 
1790   // We do this in two phases; first to check the legality of the shuffles,
1791   // and next, assuming that all shuffles are legal, to create the new nodes.
1792   for (int Phase = 0; Phase < 2; ++Phase) {
1793     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1794                                                               NewIntermedVals;
1795     for (unsigned i = 0; i < NumElems; ++i) {
1796       SDValue V = Node->getOperand(i);
1797       if (V.isUndef())
1798         continue;
1799 
1800       SDValue Vec;
1801       if (Phase)
1802         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1803       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1804     }
1805 
1806     while (IntermedVals.size() > 2) {
1807       NewIntermedVals.clear();
1808       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1809         // This vector and the next vector are shuffled together (simply to
1810         // append the one to the other).
1811         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1812 
1813         SmallVector<int, 16> FinalIndices;
1814         FinalIndices.reserve(IntermedVals[i].second.size() +
1815                              IntermedVals[i+1].second.size());
1816 
1817         int k = 0;
1818         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1819              ++j, ++k) {
1820           ShuffleVec[k] = j;
1821           FinalIndices.push_back(IntermedVals[i].second[j]);
1822         }
1823         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1824              ++j, ++k) {
1825           ShuffleVec[k] = NumElems + j;
1826           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1827         }
1828 
1829         SDValue Shuffle;
1830         if (Phase)
1831           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1832                                          IntermedVals[i+1].first,
1833                                          ShuffleVec);
1834         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1835           return false;
1836         NewIntermedVals.push_back(
1837             std::make_pair(Shuffle, std::move(FinalIndices)));
1838       }
1839 
1840       // If we had an odd number of defined values, then append the last
1841       // element to the array of new vectors.
1842       if ((IntermedVals.size() & 1) != 0)
1843         NewIntermedVals.push_back(IntermedVals.back());
1844 
1845       IntermedVals.swap(NewIntermedVals);
1846     }
1847 
1848     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1849            "Invalid number of intermediate vectors");
1850     SDValue Vec1 = IntermedVals[0].first;
1851     SDValue Vec2;
1852     if (IntermedVals.size() > 1)
1853       Vec2 = IntermedVals[1].first;
1854     else if (Phase)
1855       Vec2 = DAG.getUNDEF(VT);
1856 
1857     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1858     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1859       ShuffleVec[IntermedVals[0].second[i]] = i;
1860     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1861       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1862 
1863     if (Phase)
1864       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1865     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1866       return false;
1867   }
1868 
1869   return true;
1870 }
1871 
1872 /// Expand a BUILD_VECTOR node on targets that don't
1873 /// support the operation, but do support the resultant vector type.
1874 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1875   unsigned NumElems = Node->getNumOperands();
1876   SDValue Value1, Value2;
1877   SDLoc dl(Node);
1878   EVT VT = Node->getValueType(0);
1879   EVT OpVT = Node->getOperand(0).getValueType();
1880   EVT EltVT = VT.getVectorElementType();
1881 
1882   // If the only non-undef value is the low element, turn this into a
1883   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1884   bool isOnlyLowElement = true;
1885   bool MoreThanTwoValues = false;
1886   bool isConstant = true;
1887   for (unsigned i = 0; i < NumElems; ++i) {
1888     SDValue V = Node->getOperand(i);
1889     if (V.isUndef())
1890       continue;
1891     if (i > 0)
1892       isOnlyLowElement = false;
1893     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1894       isConstant = false;
1895 
1896     if (!Value1.getNode()) {
1897       Value1 = V;
1898     } else if (!Value2.getNode()) {
1899       if (V != Value1)
1900         Value2 = V;
1901     } else if (V != Value1 && V != Value2) {
1902       MoreThanTwoValues = true;
1903     }
1904   }
1905 
1906   if (!Value1.getNode())
1907     return DAG.getUNDEF(VT);
1908 
1909   if (isOnlyLowElement)
1910     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1911 
1912   // If all elements are constants, create a load from the constant pool.
1913   if (isConstant) {
1914     SmallVector<Constant*, 16> CV;
1915     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1916       if (ConstantFPSDNode *V =
1917           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1918         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1919       } else if (ConstantSDNode *V =
1920                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1921         if (OpVT==EltVT)
1922           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1923         else {
1924           // If OpVT and EltVT don't match, EltVT is not legal and the
1925           // element values have been promoted/truncated earlier.  Undo this;
1926           // we don't want a v16i8 to become a v16i32 for example.
1927           const ConstantInt *CI = V->getConstantIntValue();
1928           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1929                                         CI->getZExtValue()));
1930         }
1931       } else {
1932         assert(Node->getOperand(i).isUndef());
1933         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1934         CV.push_back(UndefValue::get(OpNTy));
1935       }
1936     }
1937     Constant *CP = ConstantVector::get(CV);
1938     SDValue CPIdx =
1939         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1940     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
1941     return DAG.getLoad(
1942         VT, dl, DAG.getEntryNode(), CPIdx,
1943         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1944         Alignment);
1945   }
1946 
1947   SmallSet<SDValue, 16> DefinedValues;
1948   for (unsigned i = 0; i < NumElems; ++i) {
1949     if (Node->getOperand(i).isUndef())
1950       continue;
1951     DefinedValues.insert(Node->getOperand(i));
1952   }
1953 
1954   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1955     if (!MoreThanTwoValues) {
1956       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1957       for (unsigned i = 0; i < NumElems; ++i) {
1958         SDValue V = Node->getOperand(i);
1959         if (V.isUndef())
1960           continue;
1961         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1962       }
1963       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1964         // Get the splatted value into the low element of a vector register.
1965         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1966         SDValue Vec2;
1967         if (Value2.getNode())
1968           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
1969         else
1970           Vec2 = DAG.getUNDEF(VT);
1971 
1972         // Return shuffle(LowValVec, undef, <0,0,0,0>)
1973         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1974       }
1975     } else {
1976       SDValue Res;
1977       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
1978         return Res;
1979     }
1980   }
1981 
1982   // Otherwise, we can't handle this case efficiently.
1983   return ExpandVectorBuildThroughStack(Node);
1984 }
1985 
1986 // Expand a node into a call to a libcall.  If the result value
1987 // does not fit into a register, return the lo part and set the hi part to the
1988 // by-reg argument.  If it does fit into a single register, return the result
1989 // and leave the Hi part unset.
1990 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
1991                                             bool isSigned) {
1992   TargetLowering::ArgListTy Args;
1993   TargetLowering::ArgListEntry Entry;
1994   for (const SDValue &Op : Node->op_values()) {
1995     EVT ArgVT = Op.getValueType();
1996     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1997     Entry.Node = Op;
1998     Entry.Ty = ArgTy;
1999     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2000     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2001     Args.push_back(Entry);
2002   }
2003   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2004                                          TLI.getPointerTy(DAG.getDataLayout()));
2005 
2006   EVT RetVT = Node->getValueType(0);
2007   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2008 
2009   // By default, the input chain to this libcall is the entry node of the
2010   // function. If the libcall is going to be emitted as a tail call then
2011   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2012   // node which is being folded has a non-entry input chain.
2013   SDValue InChain = DAG.getEntryNode();
2014 
2015   // isTailCall may be true since the callee does not reference caller stack
2016   // frame. Check if it's in the right position and that the return types match.
2017   SDValue TCChain = InChain;
2018   const Function &F = DAG.getMachineFunction().getFunction();
2019   bool isTailCall =
2020       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2021       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2022   if (isTailCall)
2023     InChain = TCChain;
2024 
2025   TargetLowering::CallLoweringInfo CLI(DAG);
2026   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2027   CLI.setDebugLoc(SDLoc(Node))
2028       .setChain(InChain)
2029       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2030                     std::move(Args))
2031       .setTailCall(isTailCall)
2032       .setSExtResult(signExtend)
2033       .setZExtResult(!signExtend)
2034       .setIsPostTypeLegalization(true);
2035 
2036   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2037 
2038   if (!CallInfo.second.getNode()) {
2039     DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump());
2040     // It's a tailcall, return the chain (which is the DAG root).
2041     return DAG.getRoot();
2042   }
2043 
2044   DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump());
2045   return CallInfo.first;
2046 }
2047 
2048 /// Generate a libcall taking the given operands as arguments
2049 /// and returning a result of type RetVT.
2050 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, EVT RetVT,
2051                                             const SDValue *Ops, unsigned NumOps,
2052                                             bool isSigned, const SDLoc &dl) {
2053   TargetLowering::ArgListTy Args;
2054   Args.reserve(NumOps);
2055 
2056   TargetLowering::ArgListEntry Entry;
2057   for (unsigned i = 0; i != NumOps; ++i) {
2058     Entry.Node = Ops[i];
2059     Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
2060     Entry.IsSExt = isSigned;
2061     Entry.IsZExt = !isSigned;
2062     Args.push_back(Entry);
2063   }
2064   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2065                                          TLI.getPointerTy(DAG.getDataLayout()));
2066 
2067   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2068 
2069   TargetLowering::CallLoweringInfo CLI(DAG);
2070   CLI.setDebugLoc(dl)
2071       .setChain(DAG.getEntryNode())
2072       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2073                     std::move(Args))
2074       .setSExtResult(isSigned)
2075       .setZExtResult(!isSigned)
2076       .setIsPostTypeLegalization(true);
2077 
2078   std::pair<SDValue,SDValue> CallInfo = TLI.LowerCallTo(CLI);
2079 
2080   return CallInfo.first;
2081 }
2082 
2083 // Expand a node into a call to a libcall. Similar to
2084 // ExpandLibCall except that the first operand is the in-chain.
2085 std::pair<SDValue, SDValue>
2086 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
2087                                          SDNode *Node,
2088                                          bool isSigned) {
2089   SDValue InChain = Node->getOperand(0);
2090 
2091   TargetLowering::ArgListTy Args;
2092   TargetLowering::ArgListEntry Entry;
2093   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
2094     EVT ArgVT = Node->getOperand(i).getValueType();
2095     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2096     Entry.Node = Node->getOperand(i);
2097     Entry.Ty = ArgTy;
2098     Entry.IsSExt = isSigned;
2099     Entry.IsZExt = !isSigned;
2100     Args.push_back(Entry);
2101   }
2102   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2103                                          TLI.getPointerTy(DAG.getDataLayout()));
2104 
2105   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
2106 
2107   TargetLowering::CallLoweringInfo CLI(DAG);
2108   CLI.setDebugLoc(SDLoc(Node))
2109       .setChain(InChain)
2110       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2111                     std::move(Args))
2112       .setSExtResult(isSigned)
2113       .setZExtResult(!isSigned);
2114 
2115   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2116 
2117   return CallInfo;
2118 }
2119 
2120 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2121                                               RTLIB::Libcall Call_F32,
2122                                               RTLIB::Libcall Call_F64,
2123                                               RTLIB::Libcall Call_F80,
2124                                               RTLIB::Libcall Call_F128,
2125                                               RTLIB::Libcall Call_PPCF128) {
2126   if (Node->isStrictFPOpcode())
2127     Node = DAG.mutateStrictFPToFP(Node);
2128 
2129   RTLIB::Libcall LC;
2130   switch (Node->getSimpleValueType(0).SimpleTy) {
2131   default: llvm_unreachable("Unexpected request for libcall!");
2132   case MVT::f32: LC = Call_F32; break;
2133   case MVT::f64: LC = Call_F64; break;
2134   case MVT::f80: LC = Call_F80; break;
2135   case MVT::f128: LC = Call_F128; break;
2136   case MVT::ppcf128: LC = Call_PPCF128; break;
2137   }
2138   return ExpandLibCall(LC, Node, false);
2139 }
2140 
2141 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2142                                                RTLIB::Libcall Call_I8,
2143                                                RTLIB::Libcall Call_I16,
2144                                                RTLIB::Libcall Call_I32,
2145                                                RTLIB::Libcall Call_I64,
2146                                                RTLIB::Libcall Call_I128) {
2147   RTLIB::Libcall LC;
2148   switch (Node->getSimpleValueType(0).SimpleTy) {
2149   default: llvm_unreachable("Unexpected request for libcall!");
2150   case MVT::i8:   LC = Call_I8; break;
2151   case MVT::i16:  LC = Call_I16; break;
2152   case MVT::i32:  LC = Call_I32; break;
2153   case MVT::i64:  LC = Call_I64; break;
2154   case MVT::i128: LC = Call_I128; break;
2155   }
2156   return ExpandLibCall(LC, Node, isSigned);
2157 }
2158 
2159 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2160 void
2161 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2162                                           SmallVectorImpl<SDValue> &Results) {
2163   unsigned Opcode = Node->getOpcode();
2164   bool isSigned = Opcode == ISD::SDIVREM;
2165 
2166   RTLIB::Libcall LC;
2167   switch (Node->getSimpleValueType(0).SimpleTy) {
2168   default: llvm_unreachable("Unexpected request for libcall!");
2169   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2170   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2171   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2172   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2173   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2174   }
2175 
2176   // The input chain to this libcall is the entry node of the function.
2177   // Legalizing the call will automatically add the previous call to the
2178   // dependence.
2179   SDValue InChain = DAG.getEntryNode();
2180 
2181   EVT RetVT = Node->getValueType(0);
2182   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2183 
2184   TargetLowering::ArgListTy Args;
2185   TargetLowering::ArgListEntry Entry;
2186   for (const SDValue &Op : Node->op_values()) {
2187     EVT ArgVT = Op.getValueType();
2188     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2189     Entry.Node = Op;
2190     Entry.Ty = ArgTy;
2191     Entry.IsSExt = isSigned;
2192     Entry.IsZExt = !isSigned;
2193     Args.push_back(Entry);
2194   }
2195 
2196   // Also pass the return address of the remainder.
2197   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2198   Entry.Node = FIPtr;
2199   Entry.Ty = RetTy->getPointerTo();
2200   Entry.IsSExt = isSigned;
2201   Entry.IsZExt = !isSigned;
2202   Args.push_back(Entry);
2203 
2204   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2205                                          TLI.getPointerTy(DAG.getDataLayout()));
2206 
2207   SDLoc dl(Node);
2208   TargetLowering::CallLoweringInfo CLI(DAG);
2209   CLI.setDebugLoc(dl)
2210       .setChain(InChain)
2211       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2212                     std::move(Args))
2213       .setSExtResult(isSigned)
2214       .setZExtResult(!isSigned);
2215 
2216   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2217 
2218   // Remainder is loaded back from the stack frame.
2219   SDValue Rem =
2220       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2221   Results.push_back(CallInfo.first);
2222   Results.push_back(Rem);
2223 }
2224 
2225 /// Return true if sincos libcall is available.
2226 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2227   RTLIB::Libcall LC;
2228   switch (Node->getSimpleValueType(0).SimpleTy) {
2229   default: llvm_unreachable("Unexpected request for libcall!");
2230   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2231   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2232   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2233   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2234   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2235   }
2236   return TLI.getLibcallName(LC) != nullptr;
2237 }
2238 
2239 /// Only issue sincos libcall if both sin and cos are needed.
2240 static bool useSinCos(SDNode *Node) {
2241   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2242     ? ISD::FCOS : ISD::FSIN;
2243 
2244   SDValue Op0 = Node->getOperand(0);
2245   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2246        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2247     SDNode *User = *UI;
2248     if (User == Node)
2249       continue;
2250     // The other user might have been turned into sincos already.
2251     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2252       return true;
2253   }
2254   return false;
2255 }
2256 
2257 /// Issue libcalls to sincos to compute sin / cos pairs.
2258 void
2259 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2260                                           SmallVectorImpl<SDValue> &Results) {
2261   RTLIB::Libcall LC;
2262   switch (Node->getSimpleValueType(0).SimpleTy) {
2263   default: llvm_unreachable("Unexpected request for libcall!");
2264   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2265   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2266   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2267   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2268   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2269   }
2270 
2271   // The input chain to this libcall is the entry node of the function.
2272   // Legalizing the call will automatically add the previous call to the
2273   // dependence.
2274   SDValue InChain = DAG.getEntryNode();
2275 
2276   EVT RetVT = Node->getValueType(0);
2277   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2278 
2279   TargetLowering::ArgListTy Args;
2280   TargetLowering::ArgListEntry Entry;
2281 
2282   // Pass the argument.
2283   Entry.Node = Node->getOperand(0);
2284   Entry.Ty = RetTy;
2285   Entry.IsSExt = false;
2286   Entry.IsZExt = false;
2287   Args.push_back(Entry);
2288 
2289   // Pass the return address of sin.
2290   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2291   Entry.Node = SinPtr;
2292   Entry.Ty = RetTy->getPointerTo();
2293   Entry.IsSExt = false;
2294   Entry.IsZExt = false;
2295   Args.push_back(Entry);
2296 
2297   // Also pass the return address of the cos.
2298   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2299   Entry.Node = CosPtr;
2300   Entry.Ty = RetTy->getPointerTo();
2301   Entry.IsSExt = false;
2302   Entry.IsZExt = false;
2303   Args.push_back(Entry);
2304 
2305   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2306                                          TLI.getPointerTy(DAG.getDataLayout()));
2307 
2308   SDLoc dl(Node);
2309   TargetLowering::CallLoweringInfo CLI(DAG);
2310   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2311       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2312       std::move(Args));
2313 
2314   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2315 
2316   Results.push_back(
2317       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2318   Results.push_back(
2319       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2320 }
2321 
2322 /// This function is responsible for legalizing a
2323 /// INT_TO_FP operation of the specified operand when the target requests that
2324 /// we expand it.  At this point, we know that the result and operand types are
2325 /// legal for the target.
2326 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0,
2327                                                    EVT DestVT,
2328                                                    const SDLoc &dl) {
2329   // TODO: Should any fast-math-flags be set for the created nodes?
2330   DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2331   if (Op0.getValueType() == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2332     DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2333                     "expansion\n");
2334 
2335     // Get the stack frame index of a 8 byte buffer.
2336     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2337 
2338     // word offset constant for Hi/Lo address computation
2339     SDValue WordOff = DAG.getConstant(sizeof(int), dl,
2340                                       StackSlot.getValueType());
2341     // set up Hi and Lo (into buffer) address based on endian
2342     SDValue Hi = StackSlot;
2343     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
2344                              StackSlot, WordOff);
2345     if (DAG.getDataLayout().isLittleEndian())
2346       std::swap(Hi, Lo);
2347 
2348     // if signed map to unsigned space
2349     SDValue Op0Mapped;
2350     if (isSigned) {
2351       // constant used to invert sign bit (signed to unsigned mapping)
2352       SDValue SignBit = DAG.getConstant(0x80000000u, dl, MVT::i32);
2353       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
2354     } else {
2355       Op0Mapped = Op0;
2356     }
2357     // store the lo of the constructed double - based on integer input
2358     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl, Op0Mapped, Lo,
2359                                   MachinePointerInfo());
2360     // initial hi portion of constructed double
2361     SDValue InitialHi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2362     // store the hi of the constructed double - biased exponent
2363     SDValue Store2 =
2364         DAG.getStore(Store1, dl, InitialHi, Hi, MachinePointerInfo());
2365     // load the constructed double
2366     SDValue Load =
2367         DAG.getLoad(MVT::f64, dl, Store2, StackSlot, MachinePointerInfo());
2368     // FP constant to bias correct the final result
2369     SDValue Bias = DAG.getConstantFP(isSigned ?
2370                                      BitsToDouble(0x4330000080000000ULL) :
2371                                      BitsToDouble(0x4330000000000000ULL),
2372                                      dl, MVT::f64);
2373     // subtract the bias
2374     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2375     // final result
2376     SDValue Result;
2377     // handle final rounding
2378     if (DestVT == MVT::f64) {
2379       // do nothing
2380       Result = Sub;
2381     } else if (DestVT.bitsLT(MVT::f64)) {
2382       Result = DAG.getNode(ISD::FP_ROUND, dl, DestVT, Sub,
2383                            DAG.getIntPtrConstant(0, dl));
2384     } else if (DestVT.bitsGT(MVT::f64)) {
2385       Result = DAG.getNode(ISD::FP_EXTEND, dl, DestVT, Sub);
2386     }
2387     return Result;
2388   }
2389   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2390   // Code below here assumes !isSigned without checking again.
2391 
2392   // Implementation of unsigned i64 to f64 following the algorithm in
2393   // __floatundidf in compiler_rt. This implementation has the advantage
2394   // of performing rounding correctly, both in the default rounding mode
2395   // and in all alternate rounding modes.
2396   // TODO: Generalize this for use with other types.
2397   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f64) {
2398     DEBUG(dbgs() << "Converting unsigned i64 to f64\n");
2399     SDValue TwoP52 =
2400       DAG.getConstant(UINT64_C(0x4330000000000000), dl, MVT::i64);
2401     SDValue TwoP84PlusTwoP52 =
2402       DAG.getConstantFP(BitsToDouble(UINT64_C(0x4530000000100000)), dl,
2403                         MVT::f64);
2404     SDValue TwoP84 =
2405       DAG.getConstant(UINT64_C(0x4530000000000000), dl, MVT::i64);
2406 
2407     SDValue Lo = DAG.getZeroExtendInReg(Op0, dl, MVT::i32);
2408     SDValue Hi = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0,
2409                              DAG.getConstant(32, dl, MVT::i64));
2410     SDValue LoOr = DAG.getNode(ISD::OR, dl, MVT::i64, Lo, TwoP52);
2411     SDValue HiOr = DAG.getNode(ISD::OR, dl, MVT::i64, Hi, TwoP84);
2412     SDValue LoFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, LoOr);
2413     SDValue HiFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, HiOr);
2414     SDValue HiSub = DAG.getNode(ISD::FSUB, dl, MVT::f64, HiFlt,
2415                                 TwoP84PlusTwoP52);
2416     return DAG.getNode(ISD::FADD, dl, MVT::f64, LoFlt, HiSub);
2417   }
2418 
2419   // TODO: Generalize this for use with other types.
2420   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f32) {
2421     DEBUG(dbgs() << "Converting unsigned i64 to f32\n");
2422     // For unsigned conversions, convert them to signed conversions using the
2423     // algorithm from the x86_64 __floatundidf in compiler_rt.
2424     if (!isSigned) {
2425       SDValue Fast = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Op0);
2426 
2427       SDValue ShiftConst = DAG.getConstant(
2428           1, dl, TLI.getShiftAmountTy(Op0.getValueType(), DAG.getDataLayout()));
2429       SDValue Shr = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0, ShiftConst);
2430       SDValue AndConst = DAG.getConstant(1, dl, MVT::i64);
2431       SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0, AndConst);
2432       SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And, Shr);
2433 
2434       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Or);
2435       SDValue Slow = DAG.getNode(ISD::FADD, dl, MVT::f32, SignCvt, SignCvt);
2436 
2437       // TODO: This really should be implemented using a branch rather than a
2438       // select.  We happen to get lucky and machinesink does the right
2439       // thing most of the time.  This would be a good candidate for a
2440       //pseudo-op, or, even better, for whole-function isel.
2441       SDValue SignBitTest = DAG.getSetCC(dl, getSetCCResultType(MVT::i64),
2442         Op0, DAG.getConstant(0, dl, MVT::i64), ISD::SETLT);
2443       return DAG.getSelect(dl, MVT::f32, SignBitTest, Slow, Fast);
2444     }
2445 
2446     // Otherwise, implement the fully general conversion.
2447 
2448     SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
2449          DAG.getConstant(UINT64_C(0xfffffffffffff800), dl, MVT::i64));
2450     SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And,
2451          DAG.getConstant(UINT64_C(0x800), dl, MVT::i64));
2452     SDValue And2 = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
2453          DAG.getConstant(UINT64_C(0x7ff), dl, MVT::i64));
2454     SDValue Ne = DAG.getSetCC(dl, getSetCCResultType(MVT::i64), And2,
2455                               DAG.getConstant(UINT64_C(0), dl, MVT::i64),
2456                               ISD::SETNE);
2457     SDValue Sel = DAG.getSelect(dl, MVT::i64, Ne, Or, Op0);
2458     SDValue Ge = DAG.getSetCC(dl, getSetCCResultType(MVT::i64), Op0,
2459                               DAG.getConstant(UINT64_C(0x0020000000000000), dl,
2460                                               MVT::i64),
2461                               ISD::SETUGE);
2462     SDValue Sel2 = DAG.getSelect(dl, MVT::i64, Ge, Sel, Op0);
2463     EVT SHVT = TLI.getShiftAmountTy(Sel2.getValueType(), DAG.getDataLayout());
2464 
2465     SDValue Sh = DAG.getNode(ISD::SRL, dl, MVT::i64, Sel2,
2466                              DAG.getConstant(32, dl, SHVT));
2467     SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sh);
2468     SDValue Fcvt = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Trunc);
2469     SDValue TwoP32 =
2470       DAG.getConstantFP(BitsToDouble(UINT64_C(0x41f0000000000000)), dl,
2471                         MVT::f64);
2472     SDValue Fmul = DAG.getNode(ISD::FMUL, dl, MVT::f64, TwoP32, Fcvt);
2473     SDValue Lo = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sel2);
2474     SDValue Fcvt2 = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Lo);
2475     SDValue Fadd = DAG.getNode(ISD::FADD, dl, MVT::f64, Fmul, Fcvt2);
2476     return DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Fadd,
2477                        DAG.getIntPtrConstant(0, dl));
2478   }
2479 
2480   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2481 
2482   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(Op0.getValueType()),
2483                                  Op0,
2484                                  DAG.getConstant(0, dl, Op0.getValueType()),
2485                                  ISD::SETLT);
2486   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2487           Four = DAG.getIntPtrConstant(4, dl);
2488   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2489                                     SignSet, Four, Zero);
2490 
2491   // If the sign bit of the integer is set, the large number will be treated
2492   // as a negative number.  To counteract this, the dynamic code adds an
2493   // offset depending on the data type.
2494   uint64_t FF;
2495   switch (Op0.getSimpleValueType().SimpleTy) {
2496   default: llvm_unreachable("Unsupported integer type!");
2497   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2498   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2499   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2500   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2501   }
2502   if (DAG.getDataLayout().isLittleEndian())
2503     FF <<= 32;
2504   Constant *FudgeFactor = ConstantInt::get(
2505                                        Type::getInt64Ty(*DAG.getContext()), FF);
2506 
2507   SDValue CPIdx =
2508       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2509   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
2510   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2511   Alignment = std::min(Alignment, 4u);
2512   SDValue FudgeInReg;
2513   if (DestVT == MVT::f32)
2514     FudgeInReg = DAG.getLoad(
2515         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2516         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2517         Alignment);
2518   else {
2519     SDValue Load = DAG.getExtLoad(
2520         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2521         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2522         Alignment);
2523     HandleSDNode Handle(Load);
2524     LegalizeOp(Load.getNode());
2525     FudgeInReg = Handle.getValue();
2526   }
2527 
2528   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2529 }
2530 
2531 /// This function is responsible for legalizing a
2532 /// *INT_TO_FP operation of the specified operand when the target requests that
2533 /// we promote it.  At this point, we know that the result and operand types are
2534 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2535 /// operation that takes a larger input.
2536 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT,
2537                                                     bool isSigned,
2538                                                     const SDLoc &dl) {
2539   // First step, figure out the appropriate *INT_TO_FP operation to use.
2540   EVT NewInTy = LegalOp.getValueType();
2541 
2542   unsigned OpToUse = 0;
2543 
2544   // Scan for the appropriate larger type to use.
2545   while (true) {
2546     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2547     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2548 
2549     // If the target supports SINT_TO_FP of this type, use it.
2550     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
2551       OpToUse = ISD::SINT_TO_FP;
2552       break;
2553     }
2554     if (isSigned) continue;
2555 
2556     // If the target supports UINT_TO_FP of this type, use it.
2557     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
2558       OpToUse = ISD::UINT_TO_FP;
2559       break;
2560     }
2561 
2562     // Otherwise, try a larger type.
2563   }
2564 
2565   // Okay, we found the operation and type to use.  Zero extend our input to the
2566   // desired type then run the operation on it.
2567   return DAG.getNode(OpToUse, dl, DestVT,
2568                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2569                                  dl, NewInTy, LegalOp));
2570 }
2571 
2572 /// This function is responsible for legalizing a
2573 /// FP_TO_*INT operation of the specified operand when the target requests that
2574 /// we promote it.  At this point, we know that the result and operand types are
2575 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2576 /// operation that returns a larger result.
2577 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT,
2578                                                     bool isSigned,
2579                                                     const SDLoc &dl) {
2580   // First step, figure out the appropriate FP_TO*INT operation to use.
2581   EVT NewOutTy = DestVT;
2582 
2583   unsigned OpToUse = 0;
2584 
2585   // Scan for the appropriate larger type to use.
2586   while (true) {
2587     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2588     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2589 
2590     // A larger signed type can hold all unsigned values of the requested type,
2591     // so using FP_TO_SINT is valid
2592     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
2593       OpToUse = ISD::FP_TO_SINT;
2594       break;
2595     }
2596 
2597     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2598     if (!isSigned && TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
2599       OpToUse = ISD::FP_TO_UINT;
2600       break;
2601     }
2602 
2603     // Otherwise, try a larger type.
2604   }
2605 
2606   // Okay, we found the operation and type to use.
2607   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2608 
2609   // Truncate the result of the extended FP_TO_*INT operation to the desired
2610   // size.
2611   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2612 }
2613 
2614 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
2615 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2616   EVT VT = Op.getValueType();
2617   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2618   unsigned Sz = VT.getScalarSizeInBits();
2619 
2620   SDValue Tmp, Tmp2, Tmp3;
2621 
2622   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2623   // and finally the i1 pairs.
2624   // TODO: We can easily support i4/i2 legal types if any target ever does.
2625   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2626     // Create the masks - repeating the pattern every byte.
2627     APInt MaskHi4(Sz, 0), MaskHi2(Sz, 0), MaskHi1(Sz, 0);
2628     APInt MaskLo4(Sz, 0), MaskLo2(Sz, 0), MaskLo1(Sz, 0);
2629     for (unsigned J = 0; J != Sz; J += 8) {
2630       MaskHi4 = MaskHi4 | (0xF0ull << J);
2631       MaskLo4 = MaskLo4 | (0x0Full << J);
2632       MaskHi2 = MaskHi2 | (0xCCull << J);
2633       MaskLo2 = MaskLo2 | (0x33ull << J);
2634       MaskHi1 = MaskHi1 | (0xAAull << J);
2635       MaskLo1 = MaskLo1 | (0x55ull << J);
2636     }
2637 
2638     // BSWAP if the type is wider than a single byte.
2639     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2640 
2641     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2642     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2643     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2644     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, VT));
2645     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, VT));
2646     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2647 
2648     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2649     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2650     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2651     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, VT));
2652     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, VT));
2653     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2654 
2655     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2656     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2657     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2658     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, VT));
2659     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, VT));
2660     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2661     return Tmp;
2662   }
2663 
2664   Tmp = DAG.getConstant(0, dl, VT);
2665   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2666     if (I < J)
2667       Tmp2 =
2668           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2669     else
2670       Tmp2 =
2671           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2672 
2673     APInt Shift(Sz, 1);
2674     Shift <<= J;
2675     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2676     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2677   }
2678 
2679   return Tmp;
2680 }
2681 
2682 /// Open code the operations for BSWAP of the specified operation.
2683 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2684   EVT VT = Op.getValueType();
2685   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2686   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2687   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2688   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2689   case MVT::i16:
2690     Tmp2 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2691     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2692     return DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2693   case MVT::i32:
2694     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2695     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2696     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2697     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2698     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2699                        DAG.getConstant(0xFF0000, dl, VT));
2700     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2701     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2702     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2703     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2704   case MVT::i64:
2705     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2706     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2707     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2708     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2709     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2710     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2711     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2712     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2713     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2714                        DAG.getConstant(255ULL<<48, dl, VT));
2715     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2716                        DAG.getConstant(255ULL<<40, dl, VT));
2717     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2718                        DAG.getConstant(255ULL<<32, dl, VT));
2719     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2720                        DAG.getConstant(255ULL<<24, dl, VT));
2721     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2722                        DAG.getConstant(255ULL<<16, dl, VT));
2723     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2724                        DAG.getConstant(255ULL<<8 , dl, VT));
2725     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2726     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2727     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2728     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2729     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2730     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2731     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2732   }
2733 }
2734 
2735 /// Expand the specified bitcount instruction into operations.
2736 SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
2737                                              const SDLoc &dl) {
2738   switch (Opc) {
2739   default: llvm_unreachable("Cannot expand this yet!");
2740   case ISD::CTPOP: {
2741     EVT VT = Op.getValueType();
2742     EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2743     unsigned Len = VT.getSizeInBits();
2744 
2745     assert(VT.isInteger() && Len <= 128 && Len % 8 == 0 &&
2746            "CTPOP not implemented for this type.");
2747 
2748     // This is the "best" algorithm from
2749     // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
2750 
2751     SDValue Mask55 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x55)),
2752                                      dl, VT);
2753     SDValue Mask33 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x33)),
2754                                      dl, VT);
2755     SDValue Mask0F = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x0F)),
2756                                      dl, VT);
2757     SDValue Mask01 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x01)),
2758                                      dl, VT);
2759 
2760     // v = v - ((v >> 1) & 0x55555555...)
2761     Op = DAG.getNode(ISD::SUB, dl, VT, Op,
2762                      DAG.getNode(ISD::AND, dl, VT,
2763                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2764                                              DAG.getConstant(1, dl, ShVT)),
2765                                  Mask55));
2766     // v = (v & 0x33333333...) + ((v >> 2) & 0x33333333...)
2767     Op = DAG.getNode(ISD::ADD, dl, VT,
2768                      DAG.getNode(ISD::AND, dl, VT, Op, Mask33),
2769                      DAG.getNode(ISD::AND, dl, VT,
2770                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2771                                              DAG.getConstant(2, dl, ShVT)),
2772                                  Mask33));
2773     // v = (v + (v >> 4)) & 0x0F0F0F0F...
2774     Op = DAG.getNode(ISD::AND, dl, VT,
2775                      DAG.getNode(ISD::ADD, dl, VT, Op,
2776                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2777                                              DAG.getConstant(4, dl, ShVT))),
2778                      Mask0F);
2779     // v = (v * 0x01010101...) >> (Len - 8)
2780     Op = DAG.getNode(ISD::SRL, dl, VT,
2781                      DAG.getNode(ISD::MUL, dl, VT, Op, Mask01),
2782                      DAG.getConstant(Len - 8, dl, ShVT));
2783 
2784     return Op;
2785   }
2786   case ISD::CTLZ_ZERO_UNDEF:
2787     // This trivially expands to CTLZ.
2788     return DAG.getNode(ISD::CTLZ, dl, Op.getValueType(), Op);
2789   case ISD::CTLZ: {
2790     EVT VT = Op.getValueType();
2791     unsigned Len = VT.getSizeInBits();
2792 
2793     if (TLI.isOperationLegalOrCustom(ISD::CTLZ_ZERO_UNDEF, VT)) {
2794       EVT SetCCVT = getSetCCResultType(VT);
2795       SDValue CTLZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, dl, VT, Op);
2796       SDValue Zero = DAG.getConstant(0, dl, VT);
2797       SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ);
2798       return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero,
2799                          DAG.getConstant(Len, dl, VT), CTLZ);
2800     }
2801 
2802     // for now, we do this:
2803     // x = x | (x >> 1);
2804     // x = x | (x >> 2);
2805     // ...
2806     // x = x | (x >>16);
2807     // x = x | (x >>32); // for 64-bit input
2808     // return popcount(~x);
2809     //
2810     // Ref: "Hacker's Delight" by Henry Warren
2811     EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2812     for (unsigned i = 0; (1U << i) <= (Len / 2); ++i) {
2813       SDValue Tmp3 = DAG.getConstant(1ULL << i, dl, ShVT);
2814       Op = DAG.getNode(ISD::OR, dl, VT, Op,
2815                        DAG.getNode(ISD::SRL, dl, VT, Op, Tmp3));
2816     }
2817     Op = DAG.getNOT(dl, Op, VT);
2818     return DAG.getNode(ISD::CTPOP, dl, VT, Op);
2819   }
2820   case ISD::CTTZ_ZERO_UNDEF:
2821     // This trivially expands to CTTZ.
2822     return DAG.getNode(ISD::CTTZ, dl, Op.getValueType(), Op);
2823   case ISD::CTTZ: {
2824     EVT VT = Op.getValueType();
2825     unsigned Len = VT.getSizeInBits();
2826 
2827     if (TLI.isOperationLegalOrCustom(ISD::CTTZ_ZERO_UNDEF, VT)) {
2828       EVT SetCCVT = getSetCCResultType(VT);
2829       SDValue CTTZ = DAG.getNode(ISD::CTTZ_ZERO_UNDEF, dl, VT, Op);
2830       SDValue Zero = DAG.getConstant(0, dl, VT);
2831       SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ);
2832       return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero,
2833                          DAG.getConstant(Len, dl, VT), CTTZ);
2834     }
2835 
2836     // for now, we use: { return popcount(~x & (x - 1)); }
2837     // unless the target has ctlz but not ctpop, in which case we use:
2838     // { return 32 - nlz(~x & (x-1)); }
2839     // Ref: "Hacker's Delight" by Henry Warren
2840     SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT,
2841                                DAG.getNOT(dl, Op, VT),
2842                                DAG.getNode(ISD::SUB, dl, VT, Op,
2843                                            DAG.getConstant(1, dl, VT)));
2844     // If ISD::CTLZ is legal and CTPOP isn't, then do that instead.
2845     if (!TLI.isOperationLegalOrCustom(ISD::CTPOP, VT) &&
2846         TLI.isOperationLegalOrCustom(ISD::CTLZ, VT))
2847       return DAG.getNode(ISD::SUB, dl, VT,
2848                          DAG.getConstant(VT.getSizeInBits(), dl, VT),
2849                          DAG.getNode(ISD::CTLZ, dl, VT, Tmp3));
2850     return DAG.getNode(ISD::CTPOP, dl, VT, Tmp3);
2851   }
2852   }
2853 }
2854 
2855 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2856   DEBUG(dbgs() << "Trying to expand node\n");
2857   SmallVector<SDValue, 8> Results;
2858   SDLoc dl(Node);
2859   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2860   bool NeedInvert;
2861   switch (Node->getOpcode()) {
2862   case ISD::CTPOP:
2863   case ISD::CTLZ:
2864   case ISD::CTLZ_ZERO_UNDEF:
2865   case ISD::CTTZ:
2866   case ISD::CTTZ_ZERO_UNDEF:
2867     Tmp1 = ExpandBitCount(Node->getOpcode(), Node->getOperand(0), dl);
2868     Results.push_back(Tmp1);
2869     break;
2870   case ISD::BITREVERSE:
2871     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2872     break;
2873   case ISD::BSWAP:
2874     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2875     break;
2876   case ISD::FRAMEADDR:
2877   case ISD::RETURNADDR:
2878   case ISD::FRAME_TO_ARGS_OFFSET:
2879     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2880     break;
2881   case ISD::EH_DWARF_CFA: {
2882     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2883                                         TLI.getPointerTy(DAG.getDataLayout()));
2884     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2885                                  CfaArg.getValueType(),
2886                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2887                                              CfaArg.getValueType()),
2888                                  CfaArg);
2889     SDValue FA = DAG.getNode(
2890         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2891         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2892     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2893                                   FA, Offset));
2894     break;
2895   }
2896   case ISD::FLT_ROUNDS_:
2897     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2898     break;
2899   case ISD::EH_RETURN:
2900   case ISD::EH_LABEL:
2901   case ISD::PREFETCH:
2902   case ISD::VAEND:
2903   case ISD::EH_SJLJ_LONGJMP:
2904     // If the target didn't expand these, there's nothing to do, so just
2905     // preserve the chain and be done.
2906     Results.push_back(Node->getOperand(0));
2907     break;
2908   case ISD::READCYCLECOUNTER:
2909     // If the target didn't expand this, just return 'zero' and preserve the
2910     // chain.
2911     Results.append(Node->getNumValues() - 1,
2912                    DAG.getConstant(0, dl, Node->getValueType(0)));
2913     Results.push_back(Node->getOperand(0));
2914     break;
2915   case ISD::EH_SJLJ_SETJMP:
2916     // If the target didn't expand this, just return 'zero' and preserve the
2917     // chain.
2918     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2919     Results.push_back(Node->getOperand(0));
2920     break;
2921   case ISD::ATOMIC_LOAD: {
2922     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2923     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2924     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2925     SDValue Swap = DAG.getAtomicCmpSwap(
2926         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2927         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2928         cast<AtomicSDNode>(Node)->getMemOperand());
2929     Results.push_back(Swap.getValue(0));
2930     Results.push_back(Swap.getValue(1));
2931     break;
2932   }
2933   case ISD::ATOMIC_STORE: {
2934     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2935     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2936                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2937                                  Node->getOperand(0),
2938                                  Node->getOperand(1), Node->getOperand(2),
2939                                  cast<AtomicSDNode>(Node)->getMemOperand());
2940     Results.push_back(Swap.getValue(1));
2941     break;
2942   }
2943   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2944     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2945     // splits out the success value as a comparison. Expanding the resulting
2946     // ATOMIC_CMP_SWAP will produce a libcall.
2947     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2948     SDValue Res = DAG.getAtomicCmpSwap(
2949         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2950         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2951         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2952 
2953     SDValue ExtRes = Res;
2954     SDValue LHS = Res;
2955     SDValue RHS = Node->getOperand(1);
2956 
2957     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2958     EVT OuterType = Node->getValueType(0);
2959     switch (TLI.getExtendForAtomicOps()) {
2960     case ISD::SIGN_EXTEND:
2961       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2962                         DAG.getValueType(AtomicType));
2963       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2964                         Node->getOperand(2), DAG.getValueType(AtomicType));
2965       ExtRes = LHS;
2966       break;
2967     case ISD::ZERO_EXTEND:
2968       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2969                         DAG.getValueType(AtomicType));
2970       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2971       ExtRes = LHS;
2972       break;
2973     case ISD::ANY_EXTEND:
2974       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2975       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2976       break;
2977     default:
2978       llvm_unreachable("Invalid atomic op extension");
2979     }
2980 
2981     SDValue Success =
2982         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2983 
2984     Results.push_back(ExtRes.getValue(0));
2985     Results.push_back(Success);
2986     Results.push_back(Res.getValue(1));
2987     break;
2988   }
2989   case ISD::DYNAMIC_STACKALLOC:
2990     ExpandDYNAMIC_STACKALLOC(Node, Results);
2991     break;
2992   case ISD::MERGE_VALUES:
2993     for (unsigned i = 0; i < Node->getNumValues(); i++)
2994       Results.push_back(Node->getOperand(i));
2995     break;
2996   case ISD::UNDEF: {
2997     EVT VT = Node->getValueType(0);
2998     if (VT.isInteger())
2999       Results.push_back(DAG.getConstant(0, dl, VT));
3000     else {
3001       assert(VT.isFloatingPoint() && "Unknown value type!");
3002       Results.push_back(DAG.getConstantFP(0, dl, VT));
3003     }
3004     break;
3005   }
3006   case ISD::FP_ROUND:
3007   case ISD::BITCAST:
3008     Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
3009                             Node->getValueType(0), dl);
3010     Results.push_back(Tmp1);
3011     break;
3012   case ISD::FP_EXTEND:
3013     Tmp1 = EmitStackConvert(Node->getOperand(0),
3014                             Node->getOperand(0).getValueType(),
3015                             Node->getValueType(0), dl);
3016     Results.push_back(Tmp1);
3017     break;
3018   case ISD::SIGN_EXTEND_INREG: {
3019     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
3020     EVT VT = Node->getValueType(0);
3021 
3022     // An in-register sign-extend of a boolean is a negation:
3023     // 'true' (1) sign-extended is -1.
3024     // 'false' (0) sign-extended is 0.
3025     // However, we must mask the high bits of the source operand because the
3026     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
3027 
3028     // TODO: Do this for vectors too?
3029     if (ExtraVT.getSizeInBits() == 1) {
3030       SDValue One = DAG.getConstant(1, dl, VT);
3031       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
3032       SDValue Zero = DAG.getConstant(0, dl, VT);
3033       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
3034       Results.push_back(Neg);
3035       break;
3036     }
3037 
3038     // NOTE: we could fall back on load/store here too for targets without
3039     // SRA.  However, it is doubtful that any exist.
3040     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
3041     unsigned BitsDiff = VT.getScalarSizeInBits() -
3042                         ExtraVT.getScalarSizeInBits();
3043     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
3044     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
3045                        Node->getOperand(0), ShiftCst);
3046     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
3047     Results.push_back(Tmp1);
3048     break;
3049   }
3050   case ISD::FP_ROUND_INREG: {
3051     // The only way we can lower this is to turn it into a TRUNCSTORE,
3052     // EXTLOAD pair, targeting a temporary location (a stack slot).
3053 
3054     // NOTE: there is a choice here between constantly creating new stack
3055     // slots and always reusing the same one.  We currently always create
3056     // new ones, as reuse may inhibit scheduling.
3057     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
3058     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
3059                             Node->getValueType(0), dl);
3060     Results.push_back(Tmp1);
3061     break;
3062   }
3063   case ISD::SINT_TO_FP:
3064   case ISD::UINT_TO_FP:
3065     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
3066                                 Node->getOperand(0), Node->getValueType(0), dl);
3067     Results.push_back(Tmp1);
3068     break;
3069   case ISD::FP_TO_SINT:
3070     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
3071       Results.push_back(Tmp1);
3072     break;
3073   case ISD::FP_TO_UINT: {
3074     SDValue True, False;
3075     EVT VT =  Node->getOperand(0).getValueType();
3076     EVT NVT = Node->getValueType(0);
3077     APFloat apf(DAG.EVTToAPFloatSemantics(VT),
3078                 APInt::getNullValue(VT.getSizeInBits()));
3079     APInt x = APInt::getSignMask(NVT.getSizeInBits());
3080     (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
3081     Tmp1 = DAG.getConstantFP(apf, dl, VT);
3082     Tmp2 = DAG.getSetCC(dl, getSetCCResultType(VT),
3083                         Node->getOperand(0),
3084                         Tmp1, ISD::SETLT);
3085     True = DAG.getNode(ISD::FP_TO_SINT, dl, NVT, Node->getOperand(0));
3086     // TODO: Should any fast-math-flags be set for the FSUB?
3087     False = DAG.getNode(ISD::FP_TO_SINT, dl, NVT,
3088                         DAG.getNode(ISD::FSUB, dl, VT,
3089                                     Node->getOperand(0), Tmp1));
3090     False = DAG.getNode(ISD::XOR, dl, NVT, False,
3091                         DAG.getConstant(x, dl, NVT));
3092     Tmp1 = DAG.getSelect(dl, NVT, Tmp2, True, False);
3093     Results.push_back(Tmp1);
3094     break;
3095   }
3096   case ISD::VAARG:
3097     Results.push_back(DAG.expandVAArg(Node));
3098     Results.push_back(Results[0].getValue(1));
3099     break;
3100   case ISD::VACOPY:
3101     Results.push_back(DAG.expandVACopy(Node));
3102     break;
3103   case ISD::EXTRACT_VECTOR_ELT:
3104     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
3105       // This must be an access of the only element.  Return it.
3106       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
3107                          Node->getOperand(0));
3108     else
3109       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
3110     Results.push_back(Tmp1);
3111     break;
3112   case ISD::EXTRACT_SUBVECTOR:
3113     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
3114     break;
3115   case ISD::INSERT_SUBVECTOR:
3116     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3117     break;
3118   case ISD::CONCAT_VECTORS:
3119     Results.push_back(ExpandVectorBuildThroughStack(Node));
3120     break;
3121   case ISD::SCALAR_TO_VECTOR:
3122     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3123     break;
3124   case ISD::INSERT_VECTOR_ELT:
3125     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3126                                               Node->getOperand(1),
3127                                               Node->getOperand(2), dl));
3128     break;
3129   case ISD::VECTOR_SHUFFLE: {
3130     SmallVector<int, 32> NewMask;
3131     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3132 
3133     EVT VT = Node->getValueType(0);
3134     EVT EltVT = VT.getVectorElementType();
3135     SDValue Op0 = Node->getOperand(0);
3136     SDValue Op1 = Node->getOperand(1);
3137     if (!TLI.isTypeLegal(EltVT)) {
3138       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3139 
3140       // BUILD_VECTOR operands are allowed to be wider than the element type.
3141       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3142       // it.
3143       if (NewEltVT.bitsLT(EltVT)) {
3144         // Convert shuffle node.
3145         // If original node was v4i64 and the new EltVT is i32,
3146         // cast operands to v8i32 and re-build the mask.
3147 
3148         // Calculate new VT, the size of the new VT should be equal to original.
3149         EVT NewVT =
3150             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3151                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3152         assert(NewVT.bitsEq(VT));
3153 
3154         // cast operands to new VT
3155         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3156         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3157 
3158         // Convert the shuffle mask
3159         unsigned int factor =
3160                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3161 
3162         // EltVT gets smaller
3163         assert(factor > 0);
3164 
3165         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3166           if (Mask[i] < 0) {
3167             for (unsigned fi = 0; fi < factor; ++fi)
3168               NewMask.push_back(Mask[i]);
3169           }
3170           else {
3171             for (unsigned fi = 0; fi < factor; ++fi)
3172               NewMask.push_back(Mask[i]*factor+fi);
3173           }
3174         }
3175         Mask = NewMask;
3176         VT = NewVT;
3177       }
3178       EltVT = NewEltVT;
3179     }
3180     unsigned NumElems = VT.getVectorNumElements();
3181     SmallVector<SDValue, 16> Ops;
3182     for (unsigned i = 0; i != NumElems; ++i) {
3183       if (Mask[i] < 0) {
3184         Ops.push_back(DAG.getUNDEF(EltVT));
3185         continue;
3186       }
3187       unsigned Idx = Mask[i];
3188       if (Idx < NumElems)
3189         Ops.push_back(DAG.getNode(
3190             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3191             DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout()))));
3192       else
3193         Ops.push_back(DAG.getNode(
3194             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3195             DAG.getConstant(Idx - NumElems, dl,
3196                             TLI.getVectorIdxTy(DAG.getDataLayout()))));
3197     }
3198 
3199     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3200     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3201     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3202     Results.push_back(Tmp1);
3203     break;
3204   }
3205   case ISD::EXTRACT_ELEMENT: {
3206     EVT OpTy = Node->getOperand(0).getValueType();
3207     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3208       // 1 -> Hi
3209       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3210                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3211                                          TLI.getShiftAmountTy(
3212                                              Node->getOperand(0).getValueType(),
3213                                              DAG.getDataLayout())));
3214       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3215     } else {
3216       // 0 -> Lo
3217       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3218                          Node->getOperand(0));
3219     }
3220     Results.push_back(Tmp1);
3221     break;
3222   }
3223   case ISD::STACKSAVE:
3224     // Expand to CopyFromReg if the target set
3225     // StackPointerRegisterToSaveRestore.
3226     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3227       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3228                                            Node->getValueType(0)));
3229       Results.push_back(Results[0].getValue(1));
3230     } else {
3231       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3232       Results.push_back(Node->getOperand(0));
3233     }
3234     break;
3235   case ISD::STACKRESTORE:
3236     // Expand to CopyToReg if the target set
3237     // StackPointerRegisterToSaveRestore.
3238     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3239       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3240                                          Node->getOperand(1)));
3241     } else {
3242       Results.push_back(Node->getOperand(0));
3243     }
3244     break;
3245   case ISD::GET_DYNAMIC_AREA_OFFSET:
3246     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3247     Results.push_back(Results[0].getValue(0));
3248     break;
3249   case ISD::FCOPYSIGN:
3250     Results.push_back(ExpandFCOPYSIGN(Node));
3251     break;
3252   case ISD::FNEG:
3253     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3254     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3255     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3256     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3257                        Node->getOperand(0));
3258     Results.push_back(Tmp1);
3259     break;
3260   case ISD::FABS:
3261     Results.push_back(ExpandFABS(Node));
3262     break;
3263   case ISD::SMIN:
3264   case ISD::SMAX:
3265   case ISD::UMIN:
3266   case ISD::UMAX: {
3267     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3268     ISD::CondCode Pred;
3269     switch (Node->getOpcode()) {
3270     default: llvm_unreachable("How did we get here?");
3271     case ISD::SMAX: Pred = ISD::SETGT; break;
3272     case ISD::SMIN: Pred = ISD::SETLT; break;
3273     case ISD::UMAX: Pred = ISD::SETUGT; break;
3274     case ISD::UMIN: Pred = ISD::SETULT; break;
3275     }
3276     Tmp1 = Node->getOperand(0);
3277     Tmp2 = Node->getOperand(1);
3278     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3279     Results.push_back(Tmp1);
3280     break;
3281   }
3282 
3283   case ISD::FSIN:
3284   case ISD::FCOS: {
3285     EVT VT = Node->getValueType(0);
3286     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3287     // fcos which share the same operand and both are used.
3288     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3289          isSinCosLibcallAvailable(Node, TLI))
3290         && useSinCos(Node)) {
3291       SDVTList VTs = DAG.getVTList(VT, VT);
3292       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3293       if (Node->getOpcode() == ISD::FCOS)
3294         Tmp1 = Tmp1.getValue(1);
3295       Results.push_back(Tmp1);
3296     }
3297     break;
3298   }
3299   case ISD::FMAD:
3300     llvm_unreachable("Illegal fmad should never be formed");
3301 
3302   case ISD::FP16_TO_FP:
3303     if (Node->getValueType(0) != MVT::f32) {
3304       // We can extend to types bigger than f32 in two steps without changing
3305       // the result. Since "f16 -> f32" is much more commonly available, give
3306       // CodeGen the option of emitting that before resorting to a libcall.
3307       SDValue Res =
3308           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3309       Results.push_back(
3310           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3311     }
3312     break;
3313   case ISD::FP_TO_FP16:
3314     DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3315     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3316       SDValue Op = Node->getOperand(0);
3317       MVT SVT = Op.getSimpleValueType();
3318       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3319           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3320         // Under fastmath, we can expand this node into a fround followed by
3321         // a float-half conversion.
3322         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3323                                        DAG.getIntPtrConstant(0, dl));
3324         Results.push_back(
3325             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3326       }
3327     }
3328     break;
3329   case ISD::ConstantFP: {
3330     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3331     // Check to see if this FP immediate is already legal.
3332     // If this is a legal constant, turn it into a TargetConstantFP node.
3333     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0)))
3334       Results.push_back(ExpandConstantFP(CFP, true));
3335     break;
3336   }
3337   case ISD::Constant: {
3338     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3339     Results.push_back(ExpandConstant(CP));
3340     break;
3341   }
3342   case ISD::FSUB: {
3343     EVT VT = Node->getValueType(0);
3344     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3345         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3346       const SDNodeFlags Flags = Node->getFlags();
3347       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3348       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3349       Results.push_back(Tmp1);
3350     }
3351     break;
3352   }
3353   case ISD::SUB: {
3354     EVT VT = Node->getValueType(0);
3355     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3356            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3357            "Don't know how to expand this subtraction!");
3358     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3359                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3360                                VT));
3361     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3362     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3363     break;
3364   }
3365   case ISD::UREM:
3366   case ISD::SREM: {
3367     EVT VT = Node->getValueType(0);
3368     bool isSigned = Node->getOpcode() == ISD::SREM;
3369     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
3370     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3371     Tmp2 = Node->getOperand(0);
3372     Tmp3 = Node->getOperand(1);
3373     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3374       SDVTList VTs = DAG.getVTList(VT, VT);
3375       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
3376       Results.push_back(Tmp1);
3377     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
3378       // X % Y -> X-X/Y*Y
3379       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
3380       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
3381       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
3382       Results.push_back(Tmp1);
3383     }
3384     break;
3385   }
3386   case ISD::UDIV:
3387   case ISD::SDIV: {
3388     bool isSigned = Node->getOpcode() == ISD::SDIV;
3389     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3390     EVT VT = Node->getValueType(0);
3391     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3392       SDVTList VTs = DAG.getVTList(VT, VT);
3393       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3394                          Node->getOperand(1));
3395       Results.push_back(Tmp1);
3396     }
3397     break;
3398   }
3399   case ISD::MULHU:
3400   case ISD::MULHS: {
3401     unsigned ExpandOpcode =
3402         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3403     EVT VT = Node->getValueType(0);
3404     SDVTList VTs = DAG.getVTList(VT, VT);
3405 
3406     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3407                        Node->getOperand(1));
3408     Results.push_back(Tmp1.getValue(1));
3409     break;
3410   }
3411   case ISD::UMUL_LOHI:
3412   case ISD::SMUL_LOHI: {
3413     SDValue LHS = Node->getOperand(0);
3414     SDValue RHS = Node->getOperand(1);
3415     MVT VT = LHS.getSimpleValueType();
3416     unsigned MULHOpcode =
3417         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3418 
3419     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3420       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3421       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3422       break;
3423     }
3424 
3425     SmallVector<SDValue, 4> Halves;
3426     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3427     assert(TLI.isTypeLegal(HalfType));
3428     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, Node, LHS, RHS, Halves,
3429                            HalfType, DAG,
3430                            TargetLowering::MulExpansionKind::Always)) {
3431       for (unsigned i = 0; i < 2; ++i) {
3432         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3433         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3434         SDValue Shift = DAG.getConstant(
3435             HalfType.getScalarSizeInBits(), dl,
3436             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3437         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3438         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3439       }
3440       break;
3441     }
3442     break;
3443   }
3444   case ISD::MUL: {
3445     EVT VT = Node->getValueType(0);
3446     SDVTList VTs = DAG.getVTList(VT, VT);
3447     // See if multiply or divide can be lowered using two-result operations.
3448     // We just need the low half of the multiply; try both the signed
3449     // and unsigned forms. If the target supports both SMUL_LOHI and
3450     // UMUL_LOHI, form a preference by checking which forms of plain
3451     // MULH it supports.
3452     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3453     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3454     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3455     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3456     unsigned OpToUse = 0;
3457     if (HasSMUL_LOHI && !HasMULHS) {
3458       OpToUse = ISD::SMUL_LOHI;
3459     } else if (HasUMUL_LOHI && !HasMULHU) {
3460       OpToUse = ISD::UMUL_LOHI;
3461     } else if (HasSMUL_LOHI) {
3462       OpToUse = ISD::SMUL_LOHI;
3463     } else if (HasUMUL_LOHI) {
3464       OpToUse = ISD::UMUL_LOHI;
3465     }
3466     if (OpToUse) {
3467       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3468                                     Node->getOperand(1)));
3469       break;
3470     }
3471 
3472     SDValue Lo, Hi;
3473     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3474     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3475         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3476         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3477         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3478         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3479                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3480       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3481       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3482       SDValue Shift =
3483           DAG.getConstant(HalfType.getSizeInBits(), dl,
3484                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3485       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3486       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3487     }
3488     break;
3489   }
3490   case ISD::SADDO:
3491   case ISD::SSUBO: {
3492     SDValue LHS = Node->getOperand(0);
3493     SDValue RHS = Node->getOperand(1);
3494     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::SADDO ?
3495                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
3496                               LHS, RHS);
3497     Results.push_back(Sum);
3498     EVT ResultType = Node->getValueType(1);
3499     EVT OType = getSetCCResultType(Node->getValueType(0));
3500 
3501     SDValue Zero = DAG.getConstant(0, dl, LHS.getValueType());
3502 
3503     //   LHSSign -> LHS >= 0
3504     //   RHSSign -> RHS >= 0
3505     //   SumSign -> Sum >= 0
3506     //
3507     //   Add:
3508     //   Overflow -> (LHSSign == RHSSign) && (LHSSign != SumSign)
3509     //   Sub:
3510     //   Overflow -> (LHSSign != RHSSign) && (LHSSign != SumSign)
3511     SDValue LHSSign = DAG.getSetCC(dl, OType, LHS, Zero, ISD::SETGE);
3512     SDValue RHSSign = DAG.getSetCC(dl, OType, RHS, Zero, ISD::SETGE);
3513     SDValue SignsMatch = DAG.getSetCC(dl, OType, LHSSign, RHSSign,
3514                                       Node->getOpcode() == ISD::SADDO ?
3515                                       ISD::SETEQ : ISD::SETNE);
3516 
3517     SDValue SumSign = DAG.getSetCC(dl, OType, Sum, Zero, ISD::SETGE);
3518     SDValue SumSignNE = DAG.getSetCC(dl, OType, LHSSign, SumSign, ISD::SETNE);
3519 
3520     SDValue Cmp = DAG.getNode(ISD::AND, dl, OType, SignsMatch, SumSignNE);
3521     Results.push_back(DAG.getBoolExtOrTrunc(Cmp, dl, ResultType, ResultType));
3522     break;
3523   }
3524   case ISD::UADDO:
3525   case ISD::USUBO: {
3526     SDValue LHS = Node->getOperand(0);
3527     SDValue RHS = Node->getOperand(1);
3528     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::UADDO ?
3529                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
3530                               LHS, RHS);
3531     Results.push_back(Sum);
3532 
3533     EVT ResultType = Node->getValueType(1);
3534     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3535     ISD::CondCode CC
3536       = Node->getOpcode() == ISD::UADDO ? ISD::SETULT : ISD::SETUGT;
3537     SDValue SetCC = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3538 
3539     Results.push_back(DAG.getBoolExtOrTrunc(SetCC, dl, ResultType, ResultType));
3540     break;
3541   }
3542   case ISD::UMULO:
3543   case ISD::SMULO: {
3544     EVT VT = Node->getValueType(0);
3545     EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
3546     SDValue LHS = Node->getOperand(0);
3547     SDValue RHS = Node->getOperand(1);
3548     SDValue BottomHalf;
3549     SDValue TopHalf;
3550     static const unsigned Ops[2][3] =
3551         { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
3552           { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
3553     bool isSigned = Node->getOpcode() == ISD::SMULO;
3554     if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
3555       BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
3556       TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
3557     } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
3558       BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
3559                                RHS);
3560       TopHalf = BottomHalf.getValue(1);
3561     } else if (TLI.isTypeLegal(WideVT)) {
3562       LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
3563       RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
3564       Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
3565       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3566                                DAG.getIntPtrConstant(0, dl));
3567       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3568                             DAG.getIntPtrConstant(1, dl));
3569     } else {
3570       // We can fall back to a libcall with an illegal type for the MUL if we
3571       // have a libcall big enough.
3572       // Also, we can fall back to a division in some cases, but that's a big
3573       // performance hit in the general case.
3574       RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
3575       if (WideVT == MVT::i16)
3576         LC = RTLIB::MUL_I16;
3577       else if (WideVT == MVT::i32)
3578         LC = RTLIB::MUL_I32;
3579       else if (WideVT == MVT::i64)
3580         LC = RTLIB::MUL_I64;
3581       else if (WideVT == MVT::i128)
3582         LC = RTLIB::MUL_I128;
3583       assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
3584 
3585       SDValue HiLHS;
3586       SDValue HiRHS;
3587       if (isSigned) {
3588         // The high part is obtained by SRA'ing all but one of the bits of low
3589         // part.
3590         unsigned LoSize = VT.getSizeInBits();
3591         HiLHS =
3592             DAG.getNode(ISD::SRA, dl, VT, LHS,
3593                         DAG.getConstant(LoSize - 1, dl,
3594                                         TLI.getPointerTy(DAG.getDataLayout())));
3595         HiRHS =
3596             DAG.getNode(ISD::SRA, dl, VT, RHS,
3597                         DAG.getConstant(LoSize - 1, dl,
3598                                         TLI.getPointerTy(DAG.getDataLayout())));
3599       } else {
3600           HiLHS = DAG.getConstant(0, dl, VT);
3601           HiRHS = DAG.getConstant(0, dl, VT);
3602       }
3603 
3604       // Here we're passing the 2 arguments explicitly as 4 arguments that are
3605       // pre-lowered to the correct types. This all depends upon WideVT not
3606       // being a legal type for the architecture and thus has to be split to
3607       // two arguments.
3608       SDValue Ret;
3609       if(DAG.getDataLayout().isLittleEndian()) {
3610         // Halves of WideVT are packed into registers in different order
3611         // depending on platform endianness. This is usually handled by
3612         // the C calling convention, but we can't defer to it in
3613         // the legalizer.
3614         SDValue Args[] = { LHS, HiLHS, RHS, HiRHS };
3615         Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3616       } else {
3617         SDValue Args[] = { HiLHS, LHS, HiRHS, RHS };
3618         Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3619       }
3620       assert(Ret.getOpcode() == ISD::MERGE_VALUES &&
3621              "Ret value is a collection of constituent nodes holding result.");
3622       BottomHalf = Ret.getOperand(0);
3623       TopHalf = Ret.getOperand(1);
3624     }
3625 
3626     if (isSigned) {
3627       Tmp1 = DAG.getConstant(
3628           VT.getSizeInBits() - 1, dl,
3629           TLI.getShiftAmountTy(BottomHalf.getValueType(), DAG.getDataLayout()));
3630       Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
3631       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf, Tmp1,
3632                              ISD::SETNE);
3633     } else {
3634       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf,
3635                              DAG.getConstant(0, dl, VT), ISD::SETNE);
3636     }
3637 
3638     // Truncate the result if SetCC returns a larger type than needed.
3639     EVT RType = Node->getValueType(1);
3640     if (RType.getSizeInBits() < TopHalf.getValueSizeInBits())
3641       TopHalf = DAG.getNode(ISD::TRUNCATE, dl, RType, TopHalf);
3642 
3643     assert(RType.getSizeInBits() == TopHalf.getValueSizeInBits() &&
3644            "Unexpected result type for S/UMULO legalization");
3645 
3646     Results.push_back(BottomHalf);
3647     Results.push_back(TopHalf);
3648     break;
3649   }
3650   case ISD::BUILD_PAIR: {
3651     EVT PairTy = Node->getValueType(0);
3652     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3653     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3654     Tmp2 = DAG.getNode(
3655         ISD::SHL, dl, PairTy, Tmp2,
3656         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3657                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3658     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3659     break;
3660   }
3661   case ISD::SELECT:
3662     Tmp1 = Node->getOperand(0);
3663     Tmp2 = Node->getOperand(1);
3664     Tmp3 = Node->getOperand(2);
3665     if (Tmp1.getOpcode() == ISD::SETCC) {
3666       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3667                              Tmp2, Tmp3,
3668                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3669     } else {
3670       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3671                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3672                              Tmp2, Tmp3, ISD::SETNE);
3673     }
3674     Results.push_back(Tmp1);
3675     break;
3676   case ISD::BR_JT: {
3677     SDValue Chain = Node->getOperand(0);
3678     SDValue Table = Node->getOperand(1);
3679     SDValue Index = Node->getOperand(2);
3680 
3681     const DataLayout &TD = DAG.getDataLayout();
3682     EVT PTy = TLI.getPointerTy(TD);
3683 
3684     unsigned EntrySize =
3685       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3686 
3687     Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3688                         DAG.getConstant(EntrySize, dl, Index.getValueType()));
3689     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3690                                Index, Table);
3691 
3692     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3693     SDValue LD = DAG.getExtLoad(
3694         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3695         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3696     Addr = LD;
3697     if (TLI.isJumpTableRelative()) {
3698       // For PIC, the sequence is:
3699       // BRIND(load(Jumptable + index) + RelocBase)
3700       // RelocBase can be JumpTable, GOT or some sort of global base.
3701       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3702                           TLI.getPICJumpTableRelocBase(Table, DAG));
3703     }
3704     Tmp1 = DAG.getNode(ISD::BRIND, dl, MVT::Other, LD.getValue(1), Addr);
3705     Results.push_back(Tmp1);
3706     break;
3707   }
3708   case ISD::BRCOND:
3709     // Expand brcond's setcc into its constituent parts and create a BR_CC
3710     // Node.
3711     Tmp1 = Node->getOperand(0);
3712     Tmp2 = Node->getOperand(1);
3713     if (Tmp2.getOpcode() == ISD::SETCC) {
3714       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3715                          Tmp1, Tmp2.getOperand(2),
3716                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3717                          Node->getOperand(2));
3718     } else {
3719       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3720       if (Tmp2.isUndef() ||
3721           (Tmp2.getOpcode() == ISD::AND &&
3722            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3723            dyn_cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3724         Tmp3 = Tmp2;
3725       else
3726         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3727                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3728       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3729                          DAG.getCondCode(ISD::SETNE), Tmp3,
3730                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3731                          Node->getOperand(2));
3732     }
3733     Results.push_back(Tmp1);
3734     break;
3735   case ISD::SETCC: {
3736     Tmp1 = Node->getOperand(0);
3737     Tmp2 = Node->getOperand(1);
3738     Tmp3 = Node->getOperand(2);
3739     bool Legalized = LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2,
3740                                            Tmp3, NeedInvert, dl);
3741 
3742     if (Legalized) {
3743       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3744       // condition code, create a new SETCC node.
3745       if (Tmp3.getNode())
3746         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3747                            Tmp1, Tmp2, Tmp3);
3748 
3749       // If we expanded the SETCC by inverting the condition code, then wrap
3750       // the existing SETCC in a NOT to restore the intended condition.
3751       if (NeedInvert)
3752         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3753 
3754       Results.push_back(Tmp1);
3755       break;
3756     }
3757 
3758     // Otherwise, SETCC for the given comparison type must be completely
3759     // illegal; expand it into a SELECT_CC.
3760     EVT VT = Node->getValueType(0);
3761     int TrueValue;
3762     switch (TLI.getBooleanContents(Tmp1->getValueType(0))) {
3763     case TargetLowering::ZeroOrOneBooleanContent:
3764     case TargetLowering::UndefinedBooleanContent:
3765       TrueValue = 1;
3766       break;
3767     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3768       TrueValue = -1;
3769       break;
3770     }
3771     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3772                        DAG.getConstant(TrueValue, dl, VT),
3773                        DAG.getConstant(0, dl, VT),
3774                        Tmp3);
3775     Results.push_back(Tmp1);
3776     break;
3777   }
3778   case ISD::SELECT_CC: {
3779     Tmp1 = Node->getOperand(0);   // LHS
3780     Tmp2 = Node->getOperand(1);   // RHS
3781     Tmp3 = Node->getOperand(2);   // True
3782     Tmp4 = Node->getOperand(3);   // False
3783     EVT VT = Node->getValueType(0);
3784     SDValue CC = Node->getOperand(4);
3785     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3786 
3787     if (TLI.isCondCodeLegal(CCOp, Tmp1.getSimpleValueType())) {
3788       // If the condition code is legal, then we need to expand this
3789       // node using SETCC and SELECT.
3790       EVT CmpVT = Tmp1.getValueType();
3791       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3792              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3793              "expanded.");
3794       EVT CCVT =
3795           TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), CmpVT);
3796       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC);
3797       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3798       break;
3799     }
3800 
3801     // SELECT_CC is legal, so the condition code must not be.
3802     bool Legalized = false;
3803     // Try to legalize by inverting the condition.  This is for targets that
3804     // might support an ordered version of a condition, but not the unordered
3805     // version (or vice versa).
3806     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp,
3807                                                Tmp1.getValueType().isInteger());
3808     if (TLI.isCondCodeLegal(InvCC, Tmp1.getSimpleValueType())) {
3809       // Use the new condition code and swap true and false
3810       Legalized = true;
3811       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3812     } else {
3813       // If The inverse is not legal, then try to swap the arguments using
3814       // the inverse condition code.
3815       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3816       if (TLI.isCondCodeLegal(SwapInvCC, Tmp1.getSimpleValueType())) {
3817         // The swapped inverse condition is legal, so swap true and false,
3818         // lhs and rhs.
3819         Legalized = true;
3820         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3821       }
3822     }
3823 
3824     if (!Legalized) {
3825       Legalized = LegalizeSetCCCondCode(
3826           getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC, NeedInvert,
3827           dl);
3828 
3829       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3830 
3831       // If we expanded the SETCC by inverting the condition code, then swap
3832       // the True/False operands to match.
3833       if (NeedInvert)
3834         std::swap(Tmp3, Tmp4);
3835 
3836       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3837       // condition code, create a new SELECT_CC node.
3838       if (CC.getNode()) {
3839         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3840                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3841       } else {
3842         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3843         CC = DAG.getCondCode(ISD::SETNE);
3844         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3845                            Tmp2, Tmp3, Tmp4, CC);
3846       }
3847     }
3848     Results.push_back(Tmp1);
3849     break;
3850   }
3851   case ISD::BR_CC: {
3852     Tmp1 = Node->getOperand(0);              // Chain
3853     Tmp2 = Node->getOperand(2);              // LHS
3854     Tmp3 = Node->getOperand(3);              // RHS
3855     Tmp4 = Node->getOperand(1);              // CC
3856 
3857     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
3858         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, NeedInvert, dl);
3859     (void)Legalized;
3860     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3861 
3862     // If we expanded the SETCC by inverting the condition code, then wrap
3863     // the existing SETCC in a NOT to restore the intended condition.
3864     if (NeedInvert)
3865       Tmp4 = DAG.getNOT(dl, Tmp4, Tmp4->getValueType(0));
3866 
3867     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3868     // node.
3869     if (Tmp4.getNode()) {
3870       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3871                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3872     } else {
3873       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3874       Tmp4 = DAG.getCondCode(ISD::SETNE);
3875       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3876                          Tmp2, Tmp3, Node->getOperand(4));
3877     }
3878     Results.push_back(Tmp1);
3879     break;
3880   }
3881   case ISD::BUILD_VECTOR:
3882     Results.push_back(ExpandBUILD_VECTOR(Node));
3883     break;
3884   case ISD::SRA:
3885   case ISD::SRL:
3886   case ISD::SHL: {
3887     // Scalarize vector SRA/SRL/SHL.
3888     EVT VT = Node->getValueType(0);
3889     assert(VT.isVector() && "Unable to legalize non-vector shift");
3890     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3891     unsigned NumElem = VT.getVectorNumElements();
3892 
3893     SmallVector<SDValue, 8> Scalars;
3894     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3895       SDValue Ex = DAG.getNode(
3896           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(0),
3897           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3898       SDValue Sh = DAG.getNode(
3899           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(1),
3900           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3901       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3902                                     VT.getScalarType(), Ex, Sh));
3903     }
3904 
3905     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3906     ReplaceNode(SDValue(Node, 0), Result);
3907     break;
3908   }
3909   case ISD::GLOBAL_OFFSET_TABLE:
3910   case ISD::GlobalAddress:
3911   case ISD::GlobalTLSAddress:
3912   case ISD::ExternalSymbol:
3913   case ISD::ConstantPool:
3914   case ISD::JumpTable:
3915   case ISD::INTRINSIC_W_CHAIN:
3916   case ISD::INTRINSIC_WO_CHAIN:
3917   case ISD::INTRINSIC_VOID:
3918     // FIXME: Custom lowering for these operations shouldn't return null!
3919     break;
3920   }
3921 
3922   // Replace the original node with the legalized result.
3923   if (Results.empty()) {
3924     DEBUG(dbgs() << "Cannot expand node\n");
3925     return false;
3926   }
3927 
3928   DEBUG(dbgs() << "Succesfully expanded node\n");
3929   ReplaceNode(Node, Results.data());
3930   return true;
3931 }
3932 
3933 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3934   DEBUG(dbgs() << "Trying to convert node to libcall\n");
3935   SmallVector<SDValue, 8> Results;
3936   SDLoc dl(Node);
3937   // FIXME: Check flags on the node to see if we can use a finite call.
3938   bool CanUseFiniteLibCall = TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath;
3939   unsigned Opc = Node->getOpcode();
3940   switch (Opc) {
3941   case ISD::ATOMIC_FENCE: {
3942     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3943     // FIXME: handle "fence singlethread" more efficiently.
3944     TargetLowering::ArgListTy Args;
3945 
3946     TargetLowering::CallLoweringInfo CLI(DAG);
3947     CLI.setDebugLoc(dl)
3948         .setChain(Node->getOperand(0))
3949         .setLibCallee(
3950             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3951             DAG.getExternalSymbol("__sync_synchronize",
3952                                   TLI.getPointerTy(DAG.getDataLayout())),
3953             std::move(Args));
3954 
3955     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3956 
3957     Results.push_back(CallResult.second);
3958     break;
3959   }
3960   // By default, atomic intrinsics are marked Legal and lowered. Targets
3961   // which don't support them directly, however, may want libcalls, in which
3962   // case they mark them Expand, and we get here.
3963   case ISD::ATOMIC_SWAP:
3964   case ISD::ATOMIC_LOAD_ADD:
3965   case ISD::ATOMIC_LOAD_SUB:
3966   case ISD::ATOMIC_LOAD_AND:
3967   case ISD::ATOMIC_LOAD_OR:
3968   case ISD::ATOMIC_LOAD_XOR:
3969   case ISD::ATOMIC_LOAD_NAND:
3970   case ISD::ATOMIC_LOAD_MIN:
3971   case ISD::ATOMIC_LOAD_MAX:
3972   case ISD::ATOMIC_LOAD_UMIN:
3973   case ISD::ATOMIC_LOAD_UMAX:
3974   case ISD::ATOMIC_CMP_SWAP: {
3975     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3976     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
3977     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
3978 
3979     std::pair<SDValue, SDValue> Tmp = ExpandChainLibCall(LC, Node, false);
3980     Results.push_back(Tmp.first);
3981     Results.push_back(Tmp.second);
3982     break;
3983   }
3984   case ISD::TRAP: {
3985     // If this operation is not supported, lower it to 'abort()' call
3986     TargetLowering::ArgListTy Args;
3987     TargetLowering::CallLoweringInfo CLI(DAG);
3988     CLI.setDebugLoc(dl)
3989         .setChain(Node->getOperand(0))
3990         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3991                       DAG.getExternalSymbol(
3992                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
3993                       std::move(Args));
3994     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3995 
3996     Results.push_back(CallResult.second);
3997     break;
3998   }
3999   case ISD::FMINNUM:
4000     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
4001                                       RTLIB::FMIN_F80, RTLIB::FMIN_F128,
4002                                       RTLIB::FMIN_PPCF128));
4003     break;
4004   case ISD::FMAXNUM:
4005     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
4006                                       RTLIB::FMAX_F80, RTLIB::FMAX_F128,
4007                                       RTLIB::FMAX_PPCF128));
4008     break;
4009   case ISD::FSQRT:
4010   case ISD::STRICT_FSQRT:
4011     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
4012                                       RTLIB::SQRT_F80, RTLIB::SQRT_F128,
4013                                       RTLIB::SQRT_PPCF128));
4014     break;
4015   case ISD::FSIN:
4016   case ISD::STRICT_FSIN:
4017     Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
4018                                       RTLIB::SIN_F80, RTLIB::SIN_F128,
4019                                       RTLIB::SIN_PPCF128));
4020     break;
4021   case ISD::FCOS:
4022   case ISD::STRICT_FCOS:
4023     Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
4024                                       RTLIB::COS_F80, RTLIB::COS_F128,
4025                                       RTLIB::COS_PPCF128));
4026     break;
4027   case ISD::FSINCOS:
4028     // Expand into sincos libcall.
4029     ExpandSinCosLibCall(Node, Results);
4030     break;
4031   case ISD::FLOG:
4032   case ISD::STRICT_FLOG:
4033     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log_finite))
4034       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_FINITE_F32,
4035                                         RTLIB::LOG_FINITE_F64,
4036                                         RTLIB::LOG_FINITE_F80,
4037                                         RTLIB::LOG_FINITE_F128,
4038                                         RTLIB::LOG_FINITE_PPCF128));
4039     else
4040       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
4041                                         RTLIB::LOG_F80, RTLIB::LOG_F128,
4042                                         RTLIB::LOG_PPCF128));
4043     break;
4044   case ISD::FLOG2:
4045   case ISD::STRICT_FLOG2:
4046     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log2_finite))
4047       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_FINITE_F32,
4048                                         RTLIB::LOG2_FINITE_F64,
4049                                         RTLIB::LOG2_FINITE_F80,
4050                                         RTLIB::LOG2_FINITE_F128,
4051                                         RTLIB::LOG2_FINITE_PPCF128));
4052     else
4053       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
4054                                         RTLIB::LOG2_F80, RTLIB::LOG2_F128,
4055                                         RTLIB::LOG2_PPCF128));
4056     break;
4057   case ISD::FLOG10:
4058   case ISD::STRICT_FLOG10:
4059     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log10_finite))
4060       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_FINITE_F32,
4061                                         RTLIB::LOG10_FINITE_F64,
4062                                         RTLIB::LOG10_FINITE_F80,
4063                                         RTLIB::LOG10_FINITE_F128,
4064                                         RTLIB::LOG10_FINITE_PPCF128));
4065     else
4066       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
4067                                         RTLIB::LOG10_F80, RTLIB::LOG10_F128,
4068                                         RTLIB::LOG10_PPCF128));
4069     break;
4070   case ISD::FEXP:
4071   case ISD::STRICT_FEXP:
4072     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp_finite))
4073       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_FINITE_F32,
4074                                         RTLIB::EXP_FINITE_F64,
4075                                         RTLIB::EXP_FINITE_F80,
4076                                         RTLIB::EXP_FINITE_F128,
4077                                         RTLIB::EXP_FINITE_PPCF128));
4078     else
4079       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
4080                                         RTLIB::EXP_F80, RTLIB::EXP_F128,
4081                                         RTLIB::EXP_PPCF128));
4082     break;
4083   case ISD::FEXP2:
4084   case ISD::STRICT_FEXP2:
4085     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp2_finite))
4086       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_FINITE_F32,
4087                                         RTLIB::EXP2_FINITE_F64,
4088                                         RTLIB::EXP2_FINITE_F80,
4089                                         RTLIB::EXP2_FINITE_F128,
4090                                         RTLIB::EXP2_FINITE_PPCF128));
4091     else
4092       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
4093                                         RTLIB::EXP2_F80, RTLIB::EXP2_F128,
4094                                         RTLIB::EXP2_PPCF128));
4095     break;
4096   case ISD::FTRUNC:
4097     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4098                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4099                                       RTLIB::TRUNC_PPCF128));
4100     break;
4101   case ISD::FFLOOR:
4102     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4103                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4104                                       RTLIB::FLOOR_PPCF128));
4105     break;
4106   case ISD::FCEIL:
4107     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4108                                       RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4109                                       RTLIB::CEIL_PPCF128));
4110     break;
4111   case ISD::FRINT:
4112   case ISD::STRICT_FRINT:
4113     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4114                                       RTLIB::RINT_F80, RTLIB::RINT_F128,
4115                                       RTLIB::RINT_PPCF128));
4116     break;
4117   case ISD::FNEARBYINT:
4118   case ISD::STRICT_FNEARBYINT:
4119     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4120                                       RTLIB::NEARBYINT_F64,
4121                                       RTLIB::NEARBYINT_F80,
4122                                       RTLIB::NEARBYINT_F128,
4123                                       RTLIB::NEARBYINT_PPCF128));
4124     break;
4125   case ISD::FROUND:
4126     Results.push_back(ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4127                                       RTLIB::ROUND_F64,
4128                                       RTLIB::ROUND_F80,
4129                                       RTLIB::ROUND_F128,
4130                                       RTLIB::ROUND_PPCF128));
4131     break;
4132   case ISD::FPOWI:
4133   case ISD::STRICT_FPOWI:
4134     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
4135                                       RTLIB::POWI_F80, RTLIB::POWI_F128,
4136                                       RTLIB::POWI_PPCF128));
4137     break;
4138   case ISD::FPOW:
4139   case ISD::STRICT_FPOW:
4140     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_pow_finite))
4141       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_FINITE_F32,
4142                                         RTLIB::POW_FINITE_F64,
4143                                         RTLIB::POW_FINITE_F80,
4144                                         RTLIB::POW_FINITE_F128,
4145                                         RTLIB::POW_FINITE_PPCF128));
4146     else
4147       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
4148                                         RTLIB::POW_F80, RTLIB::POW_F128,
4149                                         RTLIB::POW_PPCF128));
4150     break;
4151   case ISD::FDIV:
4152     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4153                                       RTLIB::DIV_F80, RTLIB::DIV_F128,
4154                                       RTLIB::DIV_PPCF128));
4155     break;
4156   case ISD::FREM:
4157     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4158                                       RTLIB::REM_F80, RTLIB::REM_F128,
4159                                       RTLIB::REM_PPCF128));
4160     break;
4161   case ISD::FMA:
4162   case ISD::STRICT_FMA:
4163     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4164                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
4165                                       RTLIB::FMA_PPCF128));
4166     break;
4167   case ISD::FADD:
4168     Results.push_back(ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4169                                       RTLIB::ADD_F80, RTLIB::ADD_F128,
4170                                       RTLIB::ADD_PPCF128));
4171     break;
4172   case ISD::FMUL:
4173     Results.push_back(ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4174                                       RTLIB::MUL_F80, RTLIB::MUL_F128,
4175                                       RTLIB::MUL_PPCF128));
4176     break;
4177   case ISD::FP16_TO_FP:
4178     if (Node->getValueType(0) == MVT::f32) {
4179       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4180     }
4181     break;
4182   case ISD::FP_TO_FP16: {
4183     RTLIB::Libcall LC =
4184         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4185     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4186     Results.push_back(ExpandLibCall(LC, Node, false));
4187     break;
4188   }
4189   case ISD::FSUB:
4190     Results.push_back(ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4191                                       RTLIB::SUB_F80, RTLIB::SUB_F128,
4192                                       RTLIB::SUB_PPCF128));
4193     break;
4194   case ISD::SREM:
4195     Results.push_back(ExpandIntLibCall(Node, true,
4196                                        RTLIB::SREM_I8,
4197                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4198                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4199     break;
4200   case ISD::UREM:
4201     Results.push_back(ExpandIntLibCall(Node, false,
4202                                        RTLIB::UREM_I8,
4203                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4204                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4205     break;
4206   case ISD::SDIV:
4207     Results.push_back(ExpandIntLibCall(Node, true,
4208                                        RTLIB::SDIV_I8,
4209                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4210                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4211     break;
4212   case ISD::UDIV:
4213     Results.push_back(ExpandIntLibCall(Node, false,
4214                                        RTLIB::UDIV_I8,
4215                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4216                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4217     break;
4218   case ISD::SDIVREM:
4219   case ISD::UDIVREM:
4220     // Expand into divrem libcall
4221     ExpandDivRemLibCall(Node, Results);
4222     break;
4223   case ISD::MUL:
4224     Results.push_back(ExpandIntLibCall(Node, false,
4225                                        RTLIB::MUL_I8,
4226                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4227                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4228     break;
4229   }
4230 
4231   // Replace the original node with the legalized result.
4232   if (!Results.empty()) {
4233     DEBUG(dbgs() << "Successfully converted node to libcall\n");
4234     ReplaceNode(Node, Results.data());
4235   } else
4236     DEBUG(dbgs() << "Could not convert node to libcall\n");
4237 }
4238 
4239 // Determine the vector type to use in place of an original scalar element when
4240 // promoting equally sized vectors.
4241 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4242                                         MVT EltVT, MVT NewEltVT) {
4243   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4244   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4245   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4246   return MidVT;
4247 }
4248 
4249 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4250   DEBUG(dbgs() << "Trying to promote node\n");
4251   SmallVector<SDValue, 8> Results;
4252   MVT OVT = Node->getSimpleValueType(0);
4253   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4254       Node->getOpcode() == ISD::SINT_TO_FP ||
4255       Node->getOpcode() == ISD::SETCC ||
4256       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4257       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4258     OVT = Node->getOperand(0).getSimpleValueType();
4259   }
4260   if (Node->getOpcode() == ISD::BR_CC)
4261     OVT = Node->getOperand(2).getSimpleValueType();
4262   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4263   SDLoc dl(Node);
4264   SDValue Tmp1, Tmp2, Tmp3;
4265   switch (Node->getOpcode()) {
4266   case ISD::CTTZ:
4267   case ISD::CTTZ_ZERO_UNDEF:
4268   case ISD::CTLZ:
4269   case ISD::CTLZ_ZERO_UNDEF:
4270   case ISD::CTPOP:
4271     // Zero extend the argument.
4272     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4273     if (Node->getOpcode() == ISD::CTTZ) {
4274       // The count is the same in the promoted type except if the original
4275       // value was zero.  This can be handled by setting the bit just off
4276       // the top of the original type.
4277       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4278                                         OVT.getSizeInBits());
4279       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4280                          DAG.getConstant(TopBit, dl, NVT));
4281     }
4282     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4283     // already the correct result.
4284     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4285     if (Node->getOpcode() == ISD::CTLZ ||
4286         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4287       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4288       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4289                           DAG.getConstant(NVT.getSizeInBits() -
4290                                           OVT.getSizeInBits(), dl, NVT));
4291     }
4292     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4293     break;
4294   case ISD::BITREVERSE:
4295   case ISD::BSWAP: {
4296     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4297     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4298     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4299     Tmp1 = DAG.getNode(
4300         ISD::SRL, dl, NVT, Tmp1,
4301         DAG.getConstant(DiffBits, dl,
4302                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4303     Results.push_back(Tmp1);
4304     break;
4305   }
4306   case ISD::FP_TO_UINT:
4307   case ISD::FP_TO_SINT:
4308     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
4309                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
4310     Results.push_back(Tmp1);
4311     break;
4312   case ISD::UINT_TO_FP:
4313   case ISD::SINT_TO_FP:
4314     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
4315                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
4316     Results.push_back(Tmp1);
4317     break;
4318   case ISD::VAARG: {
4319     SDValue Chain = Node->getOperand(0); // Get the chain.
4320     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4321 
4322     unsigned TruncOp;
4323     if (OVT.isVector()) {
4324       TruncOp = ISD::BITCAST;
4325     } else {
4326       assert(OVT.isInteger()
4327         && "VAARG promotion is supported only for vectors or integer types");
4328       TruncOp = ISD::TRUNCATE;
4329     }
4330 
4331     // Perform the larger operation, then convert back
4332     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4333              Node->getConstantOperandVal(3));
4334     Chain = Tmp1.getValue(1);
4335 
4336     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4337 
4338     // Modified the chain result - switch anything that used the old chain to
4339     // use the new one.
4340     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4341     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4342     if (UpdatedNodes) {
4343       UpdatedNodes->insert(Tmp2.getNode());
4344       UpdatedNodes->insert(Chain.getNode());
4345     }
4346     ReplacedNode(Node);
4347     break;
4348   }
4349   case ISD::MUL:
4350   case ISD::SDIV:
4351   case ISD::SREM:
4352   case ISD::UDIV:
4353   case ISD::UREM:
4354   case ISD::AND:
4355   case ISD::OR:
4356   case ISD::XOR: {
4357     unsigned ExtOp, TruncOp;
4358     if (OVT.isVector()) {
4359       ExtOp   = ISD::BITCAST;
4360       TruncOp = ISD::BITCAST;
4361     } else {
4362       assert(OVT.isInteger() && "Cannot promote logic operation");
4363 
4364       switch (Node->getOpcode()) {
4365       default:
4366         ExtOp = ISD::ANY_EXTEND;
4367         break;
4368       case ISD::SDIV:
4369       case ISD::SREM:
4370         ExtOp = ISD::SIGN_EXTEND;
4371         break;
4372       case ISD::UDIV:
4373       case ISD::UREM:
4374         ExtOp = ISD::ZERO_EXTEND;
4375         break;
4376       }
4377       TruncOp = ISD::TRUNCATE;
4378     }
4379     // Promote each of the values to the new type.
4380     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4381     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4382     // Perform the larger operation, then convert back
4383     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4384     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4385     break;
4386   }
4387   case ISD::UMUL_LOHI:
4388   case ISD::SMUL_LOHI: {
4389     // Promote to a multiply in a wider integer type.
4390     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4391                                                          : ISD::SIGN_EXTEND;
4392     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4393     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4394     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4395 
4396     auto &DL = DAG.getDataLayout();
4397     unsigned OriginalSize = OVT.getScalarSizeInBits();
4398     Tmp2 = DAG.getNode(
4399         ISD::SRL, dl, NVT, Tmp1,
4400         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4401     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4402     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4403     break;
4404   }
4405   case ISD::SELECT: {
4406     unsigned ExtOp, TruncOp;
4407     if (Node->getValueType(0).isVector() ||
4408         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4409       ExtOp   = ISD::BITCAST;
4410       TruncOp = ISD::BITCAST;
4411     } else if (Node->getValueType(0).isInteger()) {
4412       ExtOp   = ISD::ANY_EXTEND;
4413       TruncOp = ISD::TRUNCATE;
4414     } else {
4415       ExtOp   = ISD::FP_EXTEND;
4416       TruncOp = ISD::FP_ROUND;
4417     }
4418     Tmp1 = Node->getOperand(0);
4419     // Promote each of the values to the new type.
4420     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4421     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4422     // Perform the larger operation, then round down.
4423     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4424     if (TruncOp != ISD::FP_ROUND)
4425       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4426     else
4427       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4428                          DAG.getIntPtrConstant(0, dl));
4429     Results.push_back(Tmp1);
4430     break;
4431   }
4432   case ISD::VECTOR_SHUFFLE: {
4433     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4434 
4435     // Cast the two input vectors.
4436     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4437     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4438 
4439     // Convert the shuffle mask to the right # elements.
4440     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4441     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4442     Results.push_back(Tmp1);
4443     break;
4444   }
4445   case ISD::SETCC: {
4446     unsigned ExtOp = ISD::FP_EXTEND;
4447     if (NVT.isInteger()) {
4448       ISD::CondCode CCCode =
4449         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4450       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4451     }
4452     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4453     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4454     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
4455                                   Tmp1, Tmp2, Node->getOperand(2)));
4456     break;
4457   }
4458   case ISD::BR_CC: {
4459     unsigned ExtOp = ISD::FP_EXTEND;
4460     if (NVT.isInteger()) {
4461       ISD::CondCode CCCode =
4462         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4463       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4464     }
4465     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4466     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4467     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4468                                   Node->getOperand(0), Node->getOperand(1),
4469                                   Tmp1, Tmp2, Node->getOperand(4)));
4470     break;
4471   }
4472   case ISD::FADD:
4473   case ISD::FSUB:
4474   case ISD::FMUL:
4475   case ISD::FDIV:
4476   case ISD::FREM:
4477   case ISD::FMINNUM:
4478   case ISD::FMAXNUM:
4479   case ISD::FPOW:
4480     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4481     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4482     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4483                        Node->getFlags());
4484     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4485                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4486     break;
4487   case ISD::FMA:
4488     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4489     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4490     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4491     Results.push_back(
4492         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4493                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4494                     DAG.getIntPtrConstant(0, dl)));
4495     break;
4496   case ISD::FCOPYSIGN:
4497   case ISD::FPOWI: {
4498     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4499     Tmp2 = Node->getOperand(1);
4500     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4501 
4502     // fcopysign doesn't change anything but the sign bit, so
4503     //   (fp_round (fcopysign (fpext a), b))
4504     // is as precise as
4505     //   (fp_round (fpext a))
4506     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4507     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4508     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4509                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4510     break;
4511   }
4512   case ISD::FFLOOR:
4513   case ISD::FCEIL:
4514   case ISD::FRINT:
4515   case ISD::FNEARBYINT:
4516   case ISD::FROUND:
4517   case ISD::FTRUNC:
4518   case ISD::FNEG:
4519   case ISD::FSQRT:
4520   case ISD::FSIN:
4521   case ISD::FCOS:
4522   case ISD::FLOG:
4523   case ISD::FLOG2:
4524   case ISD::FLOG10:
4525   case ISD::FABS:
4526   case ISD::FEXP:
4527   case ISD::FEXP2:
4528     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4529     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4530     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4531                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4532     break;
4533   case ISD::BUILD_VECTOR: {
4534     MVT EltVT = OVT.getVectorElementType();
4535     MVT NewEltVT = NVT.getVectorElementType();
4536 
4537     // Handle bitcasts to a different vector type with the same total bit size
4538     //
4539     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4540     //  =>
4541     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4542 
4543     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4544            "Invalid promote type for build_vector");
4545     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4546 
4547     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4548 
4549     SmallVector<SDValue, 8> NewOps;
4550     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4551       SDValue Op = Node->getOperand(I);
4552       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4553     }
4554 
4555     SDLoc SL(Node);
4556     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4557     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4558     Results.push_back(CvtVec);
4559     break;
4560   }
4561   case ISD::EXTRACT_VECTOR_ELT: {
4562     MVT EltVT = OVT.getVectorElementType();
4563     MVT NewEltVT = NVT.getVectorElementType();
4564 
4565     // Handle bitcasts to a different vector type with the same total bit size.
4566     //
4567     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4568     //  =>
4569     //  v4i32:castx = bitcast x:v2i64
4570     //
4571     // i64 = bitcast
4572     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4573     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4574     //
4575 
4576     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4577            "Invalid promote type for extract_vector_elt");
4578     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4579 
4580     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4581     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4582 
4583     SDValue Idx = Node->getOperand(1);
4584     EVT IdxVT = Idx.getValueType();
4585     SDLoc SL(Node);
4586     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4587     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4588 
4589     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4590 
4591     SmallVector<SDValue, 8> NewOps;
4592     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4593       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4594       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4595 
4596       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4597                                 CastVec, TmpIdx);
4598       NewOps.push_back(Elt);
4599     }
4600 
4601     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4602     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4603     break;
4604   }
4605   case ISD::INSERT_VECTOR_ELT: {
4606     MVT EltVT = OVT.getVectorElementType();
4607     MVT NewEltVT = NVT.getVectorElementType();
4608 
4609     // Handle bitcasts to a different vector type with the same total bit size
4610     //
4611     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4612     //  =>
4613     //  v4i32:castx = bitcast x:v2i64
4614     //  v2i32:casty = bitcast y:i64
4615     //
4616     // v2i64 = bitcast
4617     //   (v4i32 insert_vector_elt
4618     //       (v4i32 insert_vector_elt v4i32:castx,
4619     //                                (extract_vector_elt casty, 0), 2 * z),
4620     //        (extract_vector_elt casty, 1), (2 * z + 1))
4621 
4622     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4623            "Invalid promote type for insert_vector_elt");
4624     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4625 
4626     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4627     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4628 
4629     SDValue Val = Node->getOperand(1);
4630     SDValue Idx = Node->getOperand(2);
4631     EVT IdxVT = Idx.getValueType();
4632     SDLoc SL(Node);
4633 
4634     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4635     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4636 
4637     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4638     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4639 
4640     SDValue NewVec = CastVec;
4641     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4642       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4643       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4644 
4645       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4646                                 CastVal, IdxOffset);
4647 
4648       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4649                            NewVec, Elt, InEltIdx);
4650     }
4651 
4652     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4653     break;
4654   }
4655   case ISD::SCALAR_TO_VECTOR: {
4656     MVT EltVT = OVT.getVectorElementType();
4657     MVT NewEltVT = NVT.getVectorElementType();
4658 
4659     // Handle bitcasts to different vector type with the same total bit size.
4660     //
4661     // e.g. v2i64 = scalar_to_vector x:i64
4662     //   =>
4663     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4664     //
4665 
4666     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4667     SDValue Val = Node->getOperand(0);
4668     SDLoc SL(Node);
4669 
4670     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4671     SDValue Undef = DAG.getUNDEF(MidVT);
4672 
4673     SmallVector<SDValue, 8> NewElts;
4674     NewElts.push_back(CastVal);
4675     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4676       NewElts.push_back(Undef);
4677 
4678     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4679     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4680     Results.push_back(CvtVec);
4681     break;
4682   }
4683   }
4684 
4685   // Replace the original node with the legalized result.
4686   if (!Results.empty()) {
4687     DEBUG(dbgs() << "Successfully promoted node\n");
4688     ReplaceNode(Node, Results.data());
4689   } else
4690     DEBUG(dbgs() << "Could not promote node\n");
4691 }
4692 
4693 /// This is the entry point for the file.
4694 void SelectionDAG::Legalize() {
4695   AssignTopologicalOrder();
4696 
4697   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4698   // Use a delete listener to remove nodes which were deleted during
4699   // legalization from LegalizeNodes. This is needed to handle the situation
4700   // where a new node is allocated by the object pool to the same address of a
4701   // previously deleted node.
4702   DAGNodeDeletedListener DeleteListener(
4703       *this,
4704       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4705 
4706   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4707 
4708   // Visit all the nodes. We start in topological order, so that we see
4709   // nodes with their original operands intact. Legalization can produce
4710   // new nodes which may themselves need to be legalized. Iterate until all
4711   // nodes have been legalized.
4712   while (true) {
4713     bool AnyLegalized = false;
4714     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4715       --NI;
4716 
4717       SDNode *N = &*NI;
4718       if (N->use_empty() && N != getRoot().getNode()) {
4719         ++NI;
4720         DeleteNode(N);
4721         continue;
4722       }
4723 
4724       if (LegalizedNodes.insert(N).second) {
4725         AnyLegalized = true;
4726         Legalizer.LegalizeOp(N);
4727 
4728         if (N->use_empty() && N != getRoot().getNode()) {
4729           ++NI;
4730           DeleteNode(N);
4731         }
4732       }
4733     }
4734     if (!AnyLegalized)
4735       break;
4736 
4737   }
4738 
4739   // Remove dead nodes now.
4740   RemoveDeadNodes();
4741 }
4742 
4743 bool SelectionDAG::LegalizeOp(SDNode *N,
4744                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4745   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4746   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4747 
4748   // Directly insert the node in question, and legalize it. This will recurse
4749   // as needed through operands.
4750   LegalizedNodes.insert(N);
4751   Legalizer.LegalizeOp(N);
4752 
4753   return LegalizedNodes.count(N);
4754 }
4755