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/RuntimeLibcalls.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGNodes.h"
28 #include "llvm/CodeGen/TargetFrameLowering.h"
29 #include "llvm/CodeGen/TargetLowering.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/CodeGen/ValueTypes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/MachineValueType.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include <algorithm>
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
137                              bool &NeedInvert, const SDLoc &dl);
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 Op0, 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     LLVM_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     LLVM_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     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
227 
228     DAG.ReplaceAllUsesWith(Old, New);
229     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
230       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
231                  New[i]->dump(&DAG));
232       if (UpdatedNodes)
233         UpdatedNodes->insert(New[i].getNode());
234     }
235     ReplacedNode(Old);
236   }
237 };
238 
239 } // end anonymous namespace
240 
241 /// Return a vector shuffle operation which
242 /// performs the same shuffe in terms of order or result bytes, but on a type
243 /// whose vector element type is narrower than the original shuffle type.
244 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
245 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
246     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
247     ArrayRef<int> Mask) const {
248   unsigned NumMaskElts = VT.getVectorNumElements();
249   unsigned NumDestElts = NVT.getVectorNumElements();
250   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
251 
252   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
253 
254   if (NumEltsGrowth == 1)
255     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
256 
257   SmallVector<int, 8> NewMask;
258   for (unsigned i = 0; i != NumMaskElts; ++i) {
259     int Idx = Mask[i];
260     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
261       if (Idx < 0)
262         NewMask.push_back(-1);
263       else
264         NewMask.push_back(Idx * NumEltsGrowth + j);
265     }
266   }
267   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
268   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
269   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
270 }
271 
272 /// Expands the ConstantFP node to an integer constant or
273 /// a load from the constant pool.
274 SDValue
275 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
276   bool Extend = false;
277   SDLoc dl(CFP);
278 
279   // If a FP immediate is precise when represented as a float and if the
280   // target can do an extending load from float to double, we put it into
281   // the constant pool as a float, even if it's is statically typed as a
282   // double.  This shrinks FP constants and canonicalizes them for targets where
283   // an FP extending load is the same cost as a normal load (such as on the x87
284   // fp stack or PPC FP unit).
285   EVT VT = CFP->getValueType(0);
286   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
287   if (!UseCP) {
288     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
289     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
290                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
291   }
292 
293   APFloat APF = CFP->getValueAPF();
294   EVT OrigVT = VT;
295   EVT SVT = VT;
296 
297   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
298   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
299   if (!APF.isSignaling()) {
300     while (SVT != MVT::f32 && SVT != MVT::f16) {
301       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
302       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
303           // Only do this if the target has a native EXTLOAD instruction from
304           // smaller type.
305           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
306           TLI.ShouldShrinkFPConstant(OrigVT)) {
307         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
308         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
309         VT = SVT;
310         Extend = true;
311       }
312     }
313   }
314 
315   SDValue CPIdx =
316       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
317   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
318   if (Extend) {
319     SDValue Result = DAG.getExtLoad(
320         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
321         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
322         Alignment);
323     return Result;
324   }
325   SDValue Result = DAG.getLoad(
326       OrigVT, dl, DAG.getEntryNode(), CPIdx,
327       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
328   return Result;
329 }
330 
331 /// Expands the Constant node to a load from the constant pool.
332 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
333   SDLoc dl(CP);
334   EVT VT = CP->getValueType(0);
335   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
336                                       TLI.getPointerTy(DAG.getDataLayout()));
337   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
338   SDValue Result = DAG.getLoad(
339       VT, dl, DAG.getEntryNode(), CPIdx,
340       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
341   return Result;
342 }
343 
344 /// Some target cannot handle a variable insertion index for the
345 /// INSERT_VECTOR_ELT instruction.  In this case, it
346 /// is necessary to spill the vector being inserted into to memory, perform
347 /// the insert there, and then read the result back.
348 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
349                                                              SDValue Val,
350                                                              SDValue Idx,
351                                                              const SDLoc &dl) {
352   SDValue Tmp1 = Vec;
353   SDValue Tmp2 = Val;
354   SDValue Tmp3 = Idx;
355 
356   // If the target doesn't support this, we have to spill the input vector
357   // to a temporary stack slot, update the element, then reload it.  This is
358   // badness.  We could also load the value into a vector register (either
359   // with a "move to register" or "extload into register" instruction, then
360   // permute it into place, if the idx is a constant and if the idx is
361   // supported by the target.
362   EVT VT    = Tmp1.getValueType();
363   EVT EltVT = VT.getVectorElementType();
364   SDValue StackPtr = DAG.CreateStackTemporary(VT);
365 
366   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
367 
368   // Store the vector.
369   SDValue Ch = DAG.getStore(
370       DAG.getEntryNode(), dl, Tmp1, StackPtr,
371       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
372 
373   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
374 
375   // Store the scalar value.
376   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT);
377   // Load the updated vector.
378   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
379                                                DAG.getMachineFunction(), SPFI));
380 }
381 
382 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
383                                                       SDValue Idx,
384                                                       const SDLoc &dl) {
385   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
386     // SCALAR_TO_VECTOR requires that the type of the value being inserted
387     // match the element type of the vector being created, except for
388     // integers in which case the inserted value can be over width.
389     EVT EltVT = Vec.getValueType().getVectorElementType();
390     if (Val.getValueType() == EltVT ||
391         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
392       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
393                                   Vec.getValueType(), Val);
394 
395       unsigned NumElts = Vec.getValueType().getVectorNumElements();
396       // We generate a shuffle of InVec and ScVec, so the shuffle mask
397       // should be 0,1,2,3,4,5... with the appropriate element replaced with
398       // elt 0 of the RHS.
399       SmallVector<int, 8> ShufOps;
400       for (unsigned i = 0; i != NumElts; ++i)
401         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
402 
403       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
404     }
405   }
406   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
407 }
408 
409 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
410   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
411   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
412   // FIXME: We shouldn't do this for TargetConstantFP's.
413   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
414   // to phase ordering between legalized code and the dag combiner.  This
415   // probably means that we need to integrate dag combiner and legalizer
416   // together.
417   // We generally can't do this one for long doubles.
418   SDValue Chain = ST->getChain();
419   SDValue Ptr = ST->getBasePtr();
420   unsigned Alignment = ST->getAlignment();
421   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
422   AAMDNodes AAInfo = ST->getAAInfo();
423   SDLoc dl(ST);
424   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
425     if (CFP->getValueType(0) == MVT::f32 &&
426         TLI.isTypeLegal(MVT::i32)) {
427       SDValue Con = DAG.getConstant(CFP->getValueAPF().
428                                       bitcastToAPInt().zextOrTrunc(32),
429                                     SDLoc(CFP), MVT::i32);
430       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(), Alignment,
431                           MMOFlags, AAInfo);
432     }
433 
434     if (CFP->getValueType(0) == MVT::f64) {
435       // If this target supports 64-bit registers, do a single 64-bit store.
436       if (TLI.isTypeLegal(MVT::i64)) {
437         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
438                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
439         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
440                             Alignment, MMOFlags, AAInfo);
441       }
442 
443       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
444         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
445         // stores.  If the target supports neither 32- nor 64-bits, this
446         // xform is certainly not worth it.
447         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
448         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
449         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
450         if (DAG.getDataLayout().isBigEndian())
451           std::swap(Lo, Hi);
452 
453         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), Alignment,
454                           MMOFlags, AAInfo);
455         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
456                           DAG.getConstant(4, dl, Ptr.getValueType()));
457         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
458                           ST->getPointerInfo().getWithOffset(4),
459                           MinAlign(Alignment, 4U), MMOFlags, AAInfo);
460 
461         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
462       }
463     }
464   }
465   return SDValue(nullptr, 0);
466 }
467 
468 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
469   StoreSDNode *ST = cast<StoreSDNode>(Node);
470   SDValue Chain = ST->getChain();
471   SDValue Ptr = ST->getBasePtr();
472   SDLoc dl(Node);
473 
474   unsigned Alignment = ST->getAlignment();
475   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
476   AAMDNodes AAInfo = ST->getAAInfo();
477 
478   if (!ST->isTruncatingStore()) {
479     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
480     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
481       ReplaceNode(ST, OptStore);
482       return;
483     }
484 
485     SDValue Value = ST->getValue();
486     MVT VT = Value.getSimpleValueType();
487     switch (TLI.getOperationAction(ISD::STORE, VT)) {
488     default: llvm_unreachable("This action is not supported yet!");
489     case TargetLowering::Legal: {
490       // If this is an unaligned store and the target doesn't support it,
491       // expand it.
492       EVT MemVT = ST->getMemoryVT();
493       unsigned AS = ST->getAddressSpace();
494       unsigned Align = ST->getAlignment();
495       const DataLayout &DL = DAG.getDataLayout();
496       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
497         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
498         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
499         ReplaceNode(SDValue(ST, 0), Result);
500       } else
501         LLVM_DEBUG(dbgs() << "Legal store\n");
502       break;
503     }
504     case TargetLowering::Custom: {
505       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
506       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
507       if (Res && Res != SDValue(Node, 0))
508         ReplaceNode(SDValue(Node, 0), Res);
509       return;
510     }
511     case TargetLowering::Promote: {
512       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
513       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
514              "Can only promote stores to same size type");
515       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
516       SDValue Result =
517           DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
518                        Alignment, MMOFlags, AAInfo);
519       ReplaceNode(SDValue(Node, 0), Result);
520       break;
521     }
522     }
523     return;
524   }
525 
526   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
527   SDValue Value = ST->getValue();
528   EVT StVT = ST->getMemoryVT();
529   unsigned StWidth = StVT.getSizeInBits();
530   auto &DL = DAG.getDataLayout();
531 
532   if (StWidth != StVT.getStoreSizeInBits()) {
533     // Promote to a byte-sized store with upper bits zero if not
534     // storing an integral number of bytes.  For example, promote
535     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
536     EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
537                                 StVT.getStoreSizeInBits());
538     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
539     SDValue Result =
540         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
541                           Alignment, MMOFlags, AAInfo);
542     ReplaceNode(SDValue(Node, 0), Result);
543   } else if (StWidth & (StWidth - 1)) {
544     // If not storing a power-of-2 number of bits, expand as two stores.
545     assert(!StVT.isVector() && "Unsupported truncstore!");
546     unsigned RoundWidth = 1 << Log2_32(StWidth);
547     assert(RoundWidth < StWidth);
548     unsigned ExtraWidth = StWidth - RoundWidth;
549     assert(ExtraWidth < RoundWidth);
550     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
551            "Store size not an integral number of bytes!");
552     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
553     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
554     SDValue Lo, Hi;
555     unsigned IncrementSize;
556 
557     if (DL.isLittleEndian()) {
558       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
559       // Store the bottom RoundWidth bits.
560       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
561                              RoundVT, Alignment, MMOFlags, AAInfo);
562 
563       // Store the remaining ExtraWidth bits.
564       IncrementSize = RoundWidth / 8;
565       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
566                         DAG.getConstant(IncrementSize, dl,
567                                         Ptr.getValueType()));
568       Hi = DAG.getNode(
569           ISD::SRL, dl, Value.getValueType(), Value,
570           DAG.getConstant(RoundWidth, dl,
571                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
572       Hi = DAG.getTruncStore(
573           Chain, dl, Hi, Ptr,
574           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
575           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
576     } else {
577       // Big endian - avoid unaligned stores.
578       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
579       // Store the top RoundWidth bits.
580       Hi = DAG.getNode(
581           ISD::SRL, dl, Value.getValueType(), Value,
582           DAG.getConstant(ExtraWidth, dl,
583                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
584       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
585                              RoundVT, Alignment, MMOFlags, AAInfo);
586 
587       // Store the remaining ExtraWidth bits.
588       IncrementSize = RoundWidth / 8;
589       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
590                         DAG.getConstant(IncrementSize, dl,
591                                         Ptr.getValueType()));
592       Lo = DAG.getTruncStore(
593           Chain, dl, Value, Ptr,
594           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
595           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
596     }
597 
598     // The order of the stores doesn't matter.
599     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
600     ReplaceNode(SDValue(Node, 0), Result);
601   } else {
602     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
603     default: llvm_unreachable("This action is not supported yet!");
604     case TargetLowering::Legal: {
605       EVT MemVT = ST->getMemoryVT();
606       unsigned AS = ST->getAddressSpace();
607       unsigned Align = ST->getAlignment();
608       // If this is an unaligned store and the target doesn't support it,
609       // expand it.
610       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
611         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
612         ReplaceNode(SDValue(ST, 0), Result);
613       }
614       break;
615     }
616     case TargetLowering::Custom: {
617       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
618       if (Res && Res != SDValue(Node, 0))
619         ReplaceNode(SDValue(Node, 0), Res);
620       return;
621     }
622     case TargetLowering::Expand:
623       assert(!StVT.isVector() &&
624              "Vector Stores are handled in LegalizeVectorOps");
625 
626       SDValue Result;
627 
628       // TRUNCSTORE:i16 i32 -> STORE i16
629       if (TLI.isTypeLegal(StVT)) {
630         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
631         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
632                               Alignment, MMOFlags, AAInfo);
633       } else {
634         // The in-memory type isn't legal. Truncate to the type it would promote
635         // to, and then do a truncstore.
636         Value = DAG.getNode(ISD::TRUNCATE, dl,
637                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
638                             Value);
639         Result = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
640                                    StVT, Alignment, MMOFlags, AAInfo);
641       }
642 
643       ReplaceNode(SDValue(Node, 0), Result);
644       break;
645     }
646   }
647 }
648 
649 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
650   LoadSDNode *LD = cast<LoadSDNode>(Node);
651   SDValue Chain = LD->getChain();  // The chain.
652   SDValue Ptr = LD->getBasePtr();  // The base pointer.
653   SDValue Value;                   // The value returned by the load op.
654   SDLoc dl(Node);
655 
656   ISD::LoadExtType ExtType = LD->getExtensionType();
657   if (ExtType == ISD::NON_EXTLOAD) {
658     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
659     MVT VT = Node->getSimpleValueType(0);
660     SDValue RVal = SDValue(Node, 0);
661     SDValue RChain = SDValue(Node, 1);
662 
663     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
664     default: llvm_unreachable("This action is not supported yet!");
665     case TargetLowering::Legal: {
666       EVT MemVT = LD->getMemoryVT();
667       unsigned AS = LD->getAddressSpace();
668       unsigned Align = LD->getAlignment();
669       const DataLayout &DL = DAG.getDataLayout();
670       // If this is an unaligned load and the target doesn't support it,
671       // expand it.
672       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
673         std::tie(RVal, RChain) =  TLI.expandUnalignedLoad(LD, DAG);
674       }
675       break;
676     }
677     case TargetLowering::Custom:
678       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
679         RVal = Res;
680         RChain = Res.getValue(1);
681       }
682       break;
683 
684     case TargetLowering::Promote: {
685       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
686       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
687              "Can only promote loads to same size type");
688 
689       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
690       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
691       RChain = Res.getValue(1);
692       break;
693     }
694     }
695     if (RChain.getNode() != Node) {
696       assert(RVal.getNode() != Node && "Load must be completely replaced");
697       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
698       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
699       if (UpdatedNodes) {
700         UpdatedNodes->insert(RVal.getNode());
701         UpdatedNodes->insert(RChain.getNode());
702       }
703       ReplacedNode(Node);
704     }
705     return;
706   }
707 
708   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
709   EVT SrcVT = LD->getMemoryVT();
710   unsigned SrcWidth = SrcVT.getSizeInBits();
711   unsigned Alignment = LD->getAlignment();
712   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
713   AAMDNodes AAInfo = LD->getAAInfo();
714 
715   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
716       // Some targets pretend to have an i1 loading operation, and actually
717       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
718       // bits are guaranteed to be zero; it helps the optimizers understand
719       // that these bits are zero.  It is also useful for EXTLOAD, since it
720       // tells the optimizers that those bits are undefined.  It would be
721       // nice to have an effective generic way of getting these benefits...
722       // Until such a way is found, don't insist on promoting i1 here.
723       (SrcVT != MVT::i1 ||
724        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
725          TargetLowering::Promote)) {
726     // Promote to a byte-sized load if not loading an integral number of
727     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
728     unsigned NewWidth = SrcVT.getStoreSizeInBits();
729     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
730     SDValue Ch;
731 
732     // The extra bits are guaranteed to be zero, since we stored them that
733     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
734 
735     ISD::LoadExtType NewExtType =
736       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
737 
738     SDValue Result =
739         DAG.getExtLoad(NewExtType, dl, Node->getValueType(0), Chain, Ptr,
740                        LD->getPointerInfo(), NVT, Alignment, MMOFlags, AAInfo);
741 
742     Ch = Result.getValue(1); // The chain.
743 
744     if (ExtType == ISD::SEXTLOAD)
745       // Having the top bits zero doesn't help when sign extending.
746       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
747                            Result.getValueType(),
748                            Result, DAG.getValueType(SrcVT));
749     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
750       // All the top bits are guaranteed to be zero - inform the optimizers.
751       Result = DAG.getNode(ISD::AssertZext, dl,
752                            Result.getValueType(), Result,
753                            DAG.getValueType(SrcVT));
754 
755     Value = Result;
756     Chain = Ch;
757   } else if (SrcWidth & (SrcWidth - 1)) {
758     // If not loading a power-of-2 number of bits, expand as two loads.
759     assert(!SrcVT.isVector() && "Unsupported extload!");
760     unsigned RoundWidth = 1 << Log2_32(SrcWidth);
761     assert(RoundWidth < SrcWidth);
762     unsigned ExtraWidth = SrcWidth - RoundWidth;
763     assert(ExtraWidth < RoundWidth);
764     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
765            "Load size not an integral number of bytes!");
766     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
767     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
768     SDValue Lo, Hi, Ch;
769     unsigned IncrementSize;
770     auto &DL = DAG.getDataLayout();
771 
772     if (DL.isLittleEndian()) {
773       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
774       // Load the bottom RoundWidth bits.
775       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
776                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
777                           AAInfo);
778 
779       // Load the remaining ExtraWidth bits.
780       IncrementSize = RoundWidth / 8;
781       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
782                          DAG.getConstant(IncrementSize, dl,
783                                          Ptr.getValueType()));
784       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
785                           LD->getPointerInfo().getWithOffset(IncrementSize),
786                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
787                           AAInfo);
788 
789       // Build a factor node to remember that this load is independent of
790       // the other one.
791       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
792                        Hi.getValue(1));
793 
794       // Move the top bits to the right place.
795       Hi = DAG.getNode(
796           ISD::SHL, dl, Hi.getValueType(), Hi,
797           DAG.getConstant(RoundWidth, dl,
798                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
799 
800       // Join the hi and lo parts.
801       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
802     } else {
803       // Big endian - avoid unaligned loads.
804       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
805       // Load the top RoundWidth bits.
806       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
807                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
808                           AAInfo);
809 
810       // Load the remaining ExtraWidth bits.
811       IncrementSize = RoundWidth / 8;
812       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
813                          DAG.getConstant(IncrementSize, dl,
814                                          Ptr.getValueType()));
815       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
816                           LD->getPointerInfo().getWithOffset(IncrementSize),
817                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
818                           AAInfo);
819 
820       // Build a factor node to remember that this load is independent of
821       // the other one.
822       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
823                        Hi.getValue(1));
824 
825       // Move the top bits to the right place.
826       Hi = DAG.getNode(
827           ISD::SHL, dl, Hi.getValueType(), Hi,
828           DAG.getConstant(ExtraWidth, dl,
829                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
830 
831       // Join the hi and lo parts.
832       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
833     }
834 
835     Chain = Ch;
836   } else {
837     bool isCustom = false;
838     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
839                                  SrcVT.getSimpleVT())) {
840     default: llvm_unreachable("This action is not supported yet!");
841     case TargetLowering::Custom:
842       isCustom = true;
843       LLVM_FALLTHROUGH;
844     case TargetLowering::Legal:
845       Value = SDValue(Node, 0);
846       Chain = SDValue(Node, 1);
847 
848       if (isCustom) {
849         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
850           Value = Res;
851           Chain = Res.getValue(1);
852         }
853       } else {
854         // If this is an unaligned load and the target doesn't support it,
855         // expand it.
856         EVT MemVT = LD->getMemoryVT();
857         unsigned AS = LD->getAddressSpace();
858         unsigned Align = LD->getAlignment();
859         const DataLayout &DL = DAG.getDataLayout();
860         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
861           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
862         }
863       }
864       break;
865 
866     case TargetLowering::Expand: {
867       EVT DestVT = Node->getValueType(0);
868       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
869         // If the source type is not legal, see if there is a legal extload to
870         // an intermediate type that we can then extend further.
871         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
872         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
873             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
874           // If we are loading a legal type, this is a non-extload followed by a
875           // full extend.
876           ISD::LoadExtType MidExtType =
877               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
878 
879           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
880                                         SrcVT, LD->getMemOperand());
881           unsigned ExtendOp =
882               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
883           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
884           Chain = Load.getValue(1);
885           break;
886         }
887 
888         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
889         // normal undefined upper bits behavior to allow using an in-reg extend
890         // with the illegal FP type, so load as an integer and do the
891         // from-integer conversion.
892         if (SrcVT.getScalarType() == MVT::f16) {
893           EVT ISrcVT = SrcVT.changeTypeToInteger();
894           EVT IDestVT = DestVT.changeTypeToInteger();
895           EVT LoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
896 
897           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, LoadVT,
898                                           Chain, Ptr, ISrcVT,
899                                           LD->getMemOperand());
900           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
901           Chain = Result.getValue(1);
902           break;
903         }
904       }
905 
906       assert(!SrcVT.isVector() &&
907              "Vector Loads are handled in LegalizeVectorOps");
908 
909       // FIXME: This does not work for vectors on most targets.  Sign-
910       // and zero-extend operations are currently folded into extending
911       // loads, whether they are legal or not, and then we end up here
912       // without any support for legalizing them.
913       assert(ExtType != ISD::EXTLOAD &&
914              "EXTLOAD should always be supported!");
915       // Turn the unsupported load into an EXTLOAD followed by an
916       // explicit zero/sign extend inreg.
917       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
918                                       Node->getValueType(0),
919                                       Chain, Ptr, SrcVT,
920                                       LD->getMemOperand());
921       SDValue ValRes;
922       if (ExtType == ISD::SEXTLOAD)
923         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
924                              Result.getValueType(),
925                              Result, DAG.getValueType(SrcVT));
926       else
927         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
928       Value = ValRes;
929       Chain = Result.getValue(1);
930       break;
931     }
932     }
933   }
934 
935   // Since loads produce two values, make sure to remember that we legalized
936   // both of them.
937   if (Chain.getNode() != Node) {
938     assert(Value.getNode() != Node && "Load must be completely replaced");
939     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
940     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
941     if (UpdatedNodes) {
942       UpdatedNodes->insert(Value.getNode());
943       UpdatedNodes->insert(Chain.getNode());
944     }
945     ReplacedNode(Node);
946   }
947 }
948 
949 /// Return a legal replacement for the given operation, with all legal operands.
950 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
951   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
952 
953   // Allow illegal target nodes and illegal registers.
954   if (Node->getOpcode() == ISD::TargetConstant ||
955       Node->getOpcode() == ISD::Register)
956     return;
957 
958 #ifndef NDEBUG
959   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
960     assert((TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
961               TargetLowering::TypeLegal ||
962             TLI.isTypeLegal(Node->getValueType(i))) &&
963            "Unexpected illegal type!");
964 
965   for (const SDValue &Op : Node->op_values())
966     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
967               TargetLowering::TypeLegal ||
968             TLI.isTypeLegal(Op.getValueType()) ||
969             Op.getOpcode() == ISD::TargetConstant ||
970             Op.getOpcode() == ISD::Register) &&
971             "Unexpected illegal type!");
972 #endif
973 
974   // Figure out the correct action; the way to query this varies by opcode
975   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
976   bool SimpleFinishLegalizing = true;
977   switch (Node->getOpcode()) {
978   case ISD::INTRINSIC_W_CHAIN:
979   case ISD::INTRINSIC_WO_CHAIN:
980   case ISD::INTRINSIC_VOID:
981   case ISD::STACKSAVE:
982     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
983     break;
984   case ISD::GET_DYNAMIC_AREA_OFFSET:
985     Action = TLI.getOperationAction(Node->getOpcode(),
986                                     Node->getValueType(0));
987     break;
988   case ISD::VAARG:
989     Action = TLI.getOperationAction(Node->getOpcode(),
990                                     Node->getValueType(0));
991     if (Action != TargetLowering::Promote)
992       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
993     break;
994   case ISD::FP_TO_FP16:
995   case ISD::SINT_TO_FP:
996   case ISD::UINT_TO_FP:
997   case ISD::EXTRACT_VECTOR_ELT:
998     Action = TLI.getOperationAction(Node->getOpcode(),
999                                     Node->getOperand(0).getValueType());
1000     break;
1001   case ISD::FP_ROUND_INREG:
1002   case ISD::SIGN_EXTEND_INREG: {
1003     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1004     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1005     break;
1006   }
1007   case ISD::ATOMIC_STORE:
1008     Action = TLI.getOperationAction(Node->getOpcode(),
1009                                     Node->getOperand(2).getValueType());
1010     break;
1011   case ISD::SELECT_CC:
1012   case ISD::SETCC:
1013   case ISD::BR_CC: {
1014     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1015                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1016     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
1017     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1018     ISD::CondCode CCCode =
1019         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1020     Action = TLI.getCondCodeAction(CCCode, OpVT);
1021     if (Action == TargetLowering::Legal) {
1022       if (Node->getOpcode() == ISD::SELECT_CC)
1023         Action = TLI.getOperationAction(Node->getOpcode(),
1024                                         Node->getValueType(0));
1025       else
1026         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1027     }
1028     break;
1029   }
1030   case ISD::LOAD:
1031   case ISD::STORE:
1032     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1033     // STORE expects the unlegalized operand in some cases.
1034     SimpleFinishLegalizing = false;
1035     break;
1036   case ISD::CALLSEQ_START:
1037   case ISD::CALLSEQ_END:
1038     // FIXME: This shouldn't be necessary.  These nodes have special properties
1039     // dealing with the recursive nature of legalization.  Removing this
1040     // special case should be done as part of making LegalizeDAG non-recursive.
1041     SimpleFinishLegalizing = false;
1042     break;
1043   case ISD::EXTRACT_ELEMENT:
1044   case ISD::FLT_ROUNDS_:
1045   case ISD::MERGE_VALUES:
1046   case ISD::EH_RETURN:
1047   case ISD::FRAME_TO_ARGS_OFFSET:
1048   case ISD::EH_DWARF_CFA:
1049   case ISD::EH_SJLJ_SETJMP:
1050   case ISD::EH_SJLJ_LONGJMP:
1051   case ISD::EH_SJLJ_SETUP_DISPATCH:
1052     // These operations lie about being legal: when they claim to be legal,
1053     // they should actually be expanded.
1054     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1055     if (Action == TargetLowering::Legal)
1056       Action = TargetLowering::Expand;
1057     break;
1058   case ISD::INIT_TRAMPOLINE:
1059   case ISD::ADJUST_TRAMPOLINE:
1060   case ISD::FRAMEADDR:
1061   case ISD::RETURNADDR:
1062   case ISD::ADDROFRETURNADDR:
1063     // These operations lie about being legal: when they claim to be legal,
1064     // they should actually be custom-lowered.
1065     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1066     if (Action == TargetLowering::Legal)
1067       Action = TargetLowering::Custom;
1068     break;
1069   case ISD::READCYCLECOUNTER:
1070     // READCYCLECOUNTER returns an i64, even if type legalization might have
1071     // expanded that to several smaller types.
1072     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1073     break;
1074   case ISD::READ_REGISTER:
1075   case ISD::WRITE_REGISTER:
1076     // Named register is legal in the DAG, but blocked by register name
1077     // selection if not implemented by target (to chose the correct register)
1078     // They'll be converted to Copy(To/From)Reg.
1079     Action = TargetLowering::Legal;
1080     break;
1081   case ISD::DEBUGTRAP:
1082     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1083     if (Action == TargetLowering::Expand) {
1084       // replace ISD::DEBUGTRAP with ISD::TRAP
1085       SDValue NewVal;
1086       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1087                            Node->getOperand(0));
1088       ReplaceNode(Node, NewVal.getNode());
1089       LegalizeOp(NewVal.getNode());
1090       return;
1091     }
1092     break;
1093   case ISD::STRICT_FADD:
1094   case ISD::STRICT_FSUB:
1095   case ISD::STRICT_FMUL:
1096   case ISD::STRICT_FDIV:
1097   case ISD::STRICT_FREM:
1098   case ISD::STRICT_FSQRT:
1099   case ISD::STRICT_FMA:
1100   case ISD::STRICT_FPOW:
1101   case ISD::STRICT_FPOWI:
1102   case ISD::STRICT_FSIN:
1103   case ISD::STRICT_FCOS:
1104   case ISD::STRICT_FEXP:
1105   case ISD::STRICT_FEXP2:
1106   case ISD::STRICT_FLOG:
1107   case ISD::STRICT_FLOG10:
1108   case ISD::STRICT_FLOG2:
1109   case ISD::STRICT_FRINT:
1110   case ISD::STRICT_FNEARBYINT:
1111     // These pseudo-ops get legalized as if they were their non-strict
1112     // equivalent.  For instance, if ISD::FSQRT is legal then ISD::STRICT_FSQRT
1113     // is also legal, but if ISD::FSQRT requires expansion then so does
1114     // ISD::STRICT_FSQRT.
1115     Action = TLI.getStrictFPOperationAction(Node->getOpcode(),
1116                                             Node->getValueType(0));
1117     break;
1118   case ISD::SADDSAT: {
1119     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1120     break;
1121   }
1122   case ISD::MSCATTER:
1123     Action = TLI.getOperationAction(Node->getOpcode(),
1124                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1125     break;
1126   case ISD::MSTORE:
1127     Action = TLI.getOperationAction(Node->getOpcode(),
1128                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1129     break;
1130   default:
1131     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1132       Action = TargetLowering::Legal;
1133     } else {
1134       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1135     }
1136     break;
1137   }
1138 
1139   if (SimpleFinishLegalizing) {
1140     SDNode *NewNode = Node;
1141     switch (Node->getOpcode()) {
1142     default: break;
1143     case ISD::SHL:
1144     case ISD::SRL:
1145     case ISD::SRA:
1146     case ISD::ROTL:
1147     case ISD::ROTR: {
1148       // Legalizing shifts/rotates requires adjusting the shift amount
1149       // to the appropriate width.
1150       SDValue Op0 = Node->getOperand(0);
1151       SDValue Op1 = Node->getOperand(1);
1152       if (!Op1.getValueType().isVector()) {
1153         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1154         // The getShiftAmountOperand() may create a new operand node or
1155         // return the existing one. If new operand is created we need
1156         // to update the parent node.
1157         // Do not try to legalize SAO here! It will be automatically legalized
1158         // in the next round.
1159         if (SAO != Op1)
1160           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1161       }
1162     }
1163     break;
1164     case ISD::SRL_PARTS:
1165     case ISD::SRA_PARTS:
1166     case ISD::SHL_PARTS: {
1167       // Legalizing shifts/rotates requires adjusting the shift amount
1168       // to the appropriate width.
1169       SDValue Op0 = Node->getOperand(0);
1170       SDValue Op1 = Node->getOperand(1);
1171       SDValue Op2 = Node->getOperand(2);
1172       if (!Op2.getValueType().isVector()) {
1173         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1174         // The getShiftAmountOperand() may create a new operand node or
1175         // return the existing one. If new operand is created we need
1176         // to update the parent node.
1177         if (SAO != Op2)
1178           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1179       }
1180       break;
1181     }
1182     }
1183 
1184     if (NewNode != Node) {
1185       ReplaceNode(Node, NewNode);
1186       Node = NewNode;
1187     }
1188     switch (Action) {
1189     case TargetLowering::Legal:
1190       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1191       return;
1192     case TargetLowering::Custom:
1193       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1194       // FIXME: The handling for custom lowering with multiple results is
1195       // a complete mess.
1196       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1197         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1198           return;
1199 
1200         if (Node->getNumValues() == 1) {
1201           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1202           // We can just directly replace this node with the lowered value.
1203           ReplaceNode(SDValue(Node, 0), Res);
1204           return;
1205         }
1206 
1207         SmallVector<SDValue, 8> ResultVals;
1208         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1209           ResultVals.push_back(Res.getValue(i));
1210         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1211         ReplaceNode(Node, ResultVals.data());
1212         return;
1213       }
1214       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1215       LLVM_FALLTHROUGH;
1216     case TargetLowering::Expand:
1217       if (ExpandNode(Node))
1218         return;
1219       LLVM_FALLTHROUGH;
1220     case TargetLowering::LibCall:
1221       ConvertNodeToLibcall(Node);
1222       return;
1223     case TargetLowering::Promote:
1224       PromoteNode(Node);
1225       return;
1226     }
1227   }
1228 
1229   switch (Node->getOpcode()) {
1230   default:
1231 #ifndef NDEBUG
1232     dbgs() << "NODE: ";
1233     Node->dump( &DAG);
1234     dbgs() << "\n";
1235 #endif
1236     llvm_unreachable("Do not know how to legalize this operator!");
1237 
1238   case ISD::CALLSEQ_START:
1239   case ISD::CALLSEQ_END:
1240     break;
1241   case ISD::LOAD:
1242     return LegalizeLoadOps(Node);
1243   case ISD::STORE:
1244     return LegalizeStoreOps(Node);
1245   }
1246 }
1247 
1248 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1249   SDValue Vec = Op.getOperand(0);
1250   SDValue Idx = Op.getOperand(1);
1251   SDLoc dl(Op);
1252 
1253   // Before we generate a new store to a temporary stack slot, see if there is
1254   // already one that we can use. There often is because when we scalarize
1255   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1256   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1257   // the vector. If all are expanded here, we don't want one store per vector
1258   // element.
1259 
1260   // Caches for hasPredecessorHelper
1261   SmallPtrSet<const SDNode *, 32> Visited;
1262   SmallVector<const SDNode *, 16> Worklist;
1263   Visited.insert(Op.getNode());
1264   Worklist.push_back(Idx.getNode());
1265   SDValue StackPtr, Ch;
1266   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1267        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1268     SDNode *User = *UI;
1269     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1270       if (ST->isIndexed() || ST->isTruncatingStore() ||
1271           ST->getValue() != Vec)
1272         continue;
1273 
1274       // Make sure that nothing else could have stored into the destination of
1275       // this store.
1276       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1277         continue;
1278 
1279       // If the index is dependent on the store we will introduce a cycle when
1280       // creating the load (the load uses the index, and by replacing the chain
1281       // we will make the index dependent on the load). Also, the store might be
1282       // dependent on the extractelement and introduce a cycle when creating
1283       // the load.
1284       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1285           ST->hasPredecessor(Op.getNode()))
1286         continue;
1287 
1288       StackPtr = ST->getBasePtr();
1289       Ch = SDValue(ST, 0);
1290       break;
1291     }
1292   }
1293 
1294   EVT VecVT = Vec.getValueType();
1295 
1296   if (!Ch.getNode()) {
1297     // Store the value to a temporary stack slot, then LOAD the returned part.
1298     StackPtr = DAG.CreateStackTemporary(VecVT);
1299     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1300                       MachinePointerInfo());
1301   }
1302 
1303   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1304 
1305   SDValue NewLoad;
1306 
1307   if (Op.getValueType().isVector())
1308     NewLoad =
1309         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1310   else
1311     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1312                              MachinePointerInfo(),
1313                              VecVT.getVectorElementType());
1314 
1315   // Replace the chain going out of the store, by the one out of the load.
1316   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1317 
1318   // We introduced a cycle though, so update the loads operands, making sure
1319   // to use the original store's chain as an incoming chain.
1320   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1321                                           NewLoad->op_end());
1322   NewLoadOperands[0] = Ch;
1323   NewLoad =
1324       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1325   return NewLoad;
1326 }
1327 
1328 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1329   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1330 
1331   SDValue Vec  = Op.getOperand(0);
1332   SDValue Part = Op.getOperand(1);
1333   SDValue Idx  = Op.getOperand(2);
1334   SDLoc dl(Op);
1335 
1336   // Store the value to a temporary stack slot, then LOAD the returned part.
1337   EVT VecVT = Vec.getValueType();
1338   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1339   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1340   MachinePointerInfo PtrInfo =
1341       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1342 
1343   // First store the whole vector.
1344   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1345 
1346   // Then store the inserted part.
1347   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1348 
1349   // Store the subvector.
1350   Ch = DAG.getStore(Ch, dl, Part, SubStackPtr, MachinePointerInfo());
1351 
1352   // Finally, load the updated vector.
1353   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1354 }
1355 
1356 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1357   // We can't handle this case efficiently.  Allocate a sufficiently
1358   // aligned object on the stack, store each element into it, then load
1359   // the result as a vector.
1360   // Create the stack frame object.
1361   EVT VT = Node->getValueType(0);
1362   EVT EltVT = VT.getVectorElementType();
1363   SDLoc dl(Node);
1364   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1365   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1366   MachinePointerInfo PtrInfo =
1367       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1368 
1369   // Emit a store of each element to the stack slot.
1370   SmallVector<SDValue, 8> Stores;
1371   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
1372   // Store (in the right endianness) the elements to memory.
1373   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1374     // Ignore undef elements.
1375     if (Node->getOperand(i).isUndef()) continue;
1376 
1377     unsigned Offset = TypeByteSize*i;
1378 
1379     SDValue Idx = DAG.getConstant(Offset, dl, FIPtr.getValueType());
1380     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
1381 
1382     // If the destination vector element type is narrower than the source
1383     // element type, only store the bits necessary.
1384     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
1385       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1386                                          Node->getOperand(i), Idx,
1387                                          PtrInfo.getWithOffset(Offset), EltVT));
1388     } else
1389       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1390                                     Idx, PtrInfo.getWithOffset(Offset)));
1391   }
1392 
1393   SDValue StoreChain;
1394   if (!Stores.empty())    // Not all undef elements?
1395     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1396   else
1397     StoreChain = DAG.getEntryNode();
1398 
1399   // Result is a load from the stack slot.
1400   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1401 }
1402 
1403 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1404 /// containing the sign bit if the target has no integer value capable of
1405 /// holding all bits of the floating-point value.
1406 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1407                                              const SDLoc &DL,
1408                                              SDValue Value) const {
1409   EVT FloatVT = Value.getValueType();
1410   unsigned NumBits = FloatVT.getSizeInBits();
1411   State.FloatVT = FloatVT;
1412   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1413   // Convert to an integer of the same size.
1414   if (TLI.isTypeLegal(IVT)) {
1415     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1416     State.SignMask = APInt::getSignMask(NumBits);
1417     State.SignBit = NumBits - 1;
1418     return;
1419   }
1420 
1421   auto &DataLayout = DAG.getDataLayout();
1422   // Store the float to memory, then load the sign part out as an integer.
1423   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1424   // First create a temporary that is aligned for both the load and store.
1425   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1426   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1427   // Then store the float to it.
1428   State.FloatPtr = StackPtr;
1429   MachineFunction &MF = DAG.getMachineFunction();
1430   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1431   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1432                              State.FloatPointerInfo);
1433 
1434   SDValue IntPtr;
1435   if (DataLayout.isBigEndian()) {
1436     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1437     // Load out a legal integer with the same sign bit as the float.
1438     IntPtr = StackPtr;
1439     State.IntPointerInfo = State.FloatPointerInfo;
1440   } else {
1441     // Advance the pointer so that the loaded byte will contain the sign bit.
1442     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1443     IntPtr = DAG.getNode(ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
1444                       DAG.getConstant(ByteOffset, DL, StackPtr.getValueType()));
1445     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1446                                                              ByteOffset);
1447   }
1448 
1449   State.IntPtr = IntPtr;
1450   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1451                                   State.IntPointerInfo, MVT::i8);
1452   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1453   State.SignBit = 7;
1454 }
1455 
1456 /// Replace the integer value produced by getSignAsIntValue() with a new value
1457 /// and cast the result back to a floating-point type.
1458 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1459                                               const SDLoc &DL,
1460                                               SDValue NewIntValue) const {
1461   if (!State.Chain)
1462     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1463 
1464   // Override the part containing the sign bit in the value stored on the stack.
1465   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1466                                     State.IntPointerInfo, MVT::i8);
1467   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1468                      State.FloatPointerInfo);
1469 }
1470 
1471 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1472   SDLoc DL(Node);
1473   SDValue Mag = Node->getOperand(0);
1474   SDValue Sign = Node->getOperand(1);
1475 
1476   // Get sign bit into an integer value.
1477   FloatSignAsInt SignAsInt;
1478   getSignAsIntValue(SignAsInt, DL, Sign);
1479 
1480   EVT IntVT = SignAsInt.IntValue.getValueType();
1481   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1482   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1483                                 SignMask);
1484 
1485   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1486   EVT FloatVT = Mag.getValueType();
1487   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1488       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1489     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1490     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1491     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1492                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1493     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1494   }
1495 
1496   // Transform Mag value to integer, and clear the sign bit.
1497   FloatSignAsInt MagAsInt;
1498   getSignAsIntValue(MagAsInt, DL, Mag);
1499   EVT MagVT = MagAsInt.IntValue.getValueType();
1500   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1501   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1502                                     ClearSignMask);
1503 
1504   // Get the signbit at the right position for MagAsInt.
1505   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1506   EVT ShiftVT = IntVT;
1507   if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1508     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1509     ShiftVT = MagVT;
1510   }
1511   if (ShiftAmount > 0) {
1512     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1513     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1514   } else if (ShiftAmount < 0) {
1515     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1516     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1517   }
1518   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1519     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1520   }
1521 
1522   // Store the part with the modified sign and convert back to float.
1523   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1524   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1525 }
1526 
1527 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1528   SDLoc DL(Node);
1529   SDValue Value = Node->getOperand(0);
1530 
1531   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1532   EVT FloatVT = Value.getValueType();
1533   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1534     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1535     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1536   }
1537 
1538   // Transform value to integer, clear the sign bit and transform back.
1539   FloatSignAsInt ValueAsInt;
1540   getSignAsIntValue(ValueAsInt, DL, Value);
1541   EVT IntVT = ValueAsInt.IntValue.getValueType();
1542   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1543   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1544                                     ClearSignMask);
1545   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1546 }
1547 
1548 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1549                                            SmallVectorImpl<SDValue> &Results) {
1550   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1551   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1552           " not tell us which reg is the stack pointer!");
1553   SDLoc dl(Node);
1554   EVT VT = Node->getValueType(0);
1555   SDValue Tmp1 = SDValue(Node, 0);
1556   SDValue Tmp2 = SDValue(Node, 1);
1557   SDValue Tmp3 = Node->getOperand(2);
1558   SDValue Chain = Tmp1.getOperand(0);
1559 
1560   // Chain the dynamic stack allocation so that it doesn't modify the stack
1561   // pointer when other instructions are using the stack.
1562   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1563 
1564   SDValue Size  = Tmp2.getOperand(1);
1565   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1566   Chain = SP.getValue(1);
1567   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
1568   unsigned StackAlign =
1569       DAG.getSubtarget().getFrameLowering()->getStackAlignment();
1570   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
1571   if (Align > StackAlign)
1572     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1573                        DAG.getConstant(-(uint64_t)Align, dl, VT));
1574   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1575 
1576   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1577                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1578 
1579   Results.push_back(Tmp1);
1580   Results.push_back(Tmp2);
1581 }
1582 
1583 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1584 /// target.
1585 ///
1586 /// If the SETCC has been legalized using AND / OR, then the legalized node
1587 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1588 /// will be set to false.
1589 ///
1590 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1591 /// then the values of LHS and RHS will be swapped, CC will be set to the
1592 /// new condition, and NeedInvert will be set to false.
1593 ///
1594 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1595 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1596 /// will be set to true. The caller must invert the result of the SETCC with
1597 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1598 /// of a true/false result.
1599 ///
1600 /// \returns true if the SetCC has been legalized, false if it hasn't.
1601 bool SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT, SDValue &LHS,
1602                                                  SDValue &RHS, SDValue &CC,
1603                                                  bool &NeedInvert,
1604                                                  const SDLoc &dl) {
1605   MVT OpVT = LHS.getSimpleValueType();
1606   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1607   NeedInvert = false;
1608   bool NeedSwap = false;
1609   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1610   default: llvm_unreachable("Unknown condition code action!");
1611   case TargetLowering::Legal:
1612     // Nothing to do.
1613     break;
1614   case TargetLowering::Expand: {
1615     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1616     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1617       std::swap(LHS, RHS);
1618       CC = DAG.getCondCode(InvCC);
1619       return true;
1620     }
1621     // Swapping operands didn't work. Try inverting the condition.
1622     InvCC = getSetCCInverse(CCCode, OpVT.isInteger());
1623     if (!TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1624       // If inverting the condition is not enough, try swapping operands
1625       // on top of it.
1626       InvCC = ISD::getSetCCSwappedOperands(InvCC);
1627       NeedSwap = true;
1628     }
1629     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1630       CC = DAG.getCondCode(InvCC);
1631       NeedInvert = true;
1632       if (NeedSwap)
1633         std::swap(LHS, RHS);
1634       return true;
1635     }
1636 
1637     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1638     unsigned Opc = 0;
1639     switch (CCCode) {
1640     default: llvm_unreachable("Don't know how to expand this condition!");
1641     case ISD::SETO:
1642         assert(TLI.isCondCodeLegal(ISD::SETOEQ, OpVT)
1643             && "If SETO is expanded, SETOEQ must be legal!");
1644         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1645     case ISD::SETUO:
1646         assert(TLI.isCondCodeLegal(ISD::SETUNE, OpVT)
1647             && "If SETUO is expanded, SETUNE must be legal!");
1648         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1649     case ISD::SETOEQ:
1650     case ISD::SETOGT:
1651     case ISD::SETOGE:
1652     case ISD::SETOLT:
1653     case ISD::SETOLE:
1654     case ISD::SETONE:
1655     case ISD::SETUEQ:
1656     case ISD::SETUNE:
1657     case ISD::SETUGT:
1658     case ISD::SETUGE:
1659     case ISD::SETULT:
1660     case ISD::SETULE:
1661         // If we are floating point, assign and break, otherwise fall through.
1662         if (!OpVT.isInteger()) {
1663           // We can use the 4th bit to tell if we are the unordered
1664           // or ordered version of the opcode.
1665           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1666           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1667           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1668           break;
1669         }
1670         // Fallthrough if we are unsigned integer.
1671         LLVM_FALLTHROUGH;
1672     case ISD::SETLE:
1673     case ISD::SETGT:
1674     case ISD::SETGE:
1675     case ISD::SETLT:
1676     case ISD::SETNE:
1677     case ISD::SETEQ:
1678       // If all combinations of inverting the condition and swapping operands
1679       // didn't work then we have no means to expand the condition.
1680       llvm_unreachable("Don't know how to expand this condition!");
1681     }
1682 
1683     SDValue SetCC1, SetCC2;
1684     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1685       // If we aren't the ordered or unorder operation,
1686       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1687       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
1688       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
1689     } else {
1690       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1691       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1);
1692       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2);
1693     }
1694     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1695     RHS = SDValue();
1696     CC  = SDValue();
1697     return true;
1698   }
1699   }
1700   return false;
1701 }
1702 
1703 /// Emit a store/load combination to the stack.  This stores
1704 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1705 /// a load from the stack slot to DestVT, extending it if needed.
1706 /// The resultant code need not be legal.
1707 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1708                                                EVT DestVT, const SDLoc &dl) {
1709   // Create the stack frame object.
1710   unsigned SrcAlign = DAG.getDataLayout().getPrefTypeAlignment(
1711       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1712   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
1713 
1714   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1715   int SPFI = StackPtrFI->getIndex();
1716   MachinePointerInfo PtrInfo =
1717       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1718 
1719   unsigned SrcSize = SrcOp.getValueSizeInBits();
1720   unsigned SlotSize = SlotVT.getSizeInBits();
1721   unsigned DestSize = DestVT.getSizeInBits();
1722   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1723   unsigned DestAlign = DAG.getDataLayout().getPrefTypeAlignment(DestType);
1724 
1725   // Emit a store to the stack slot.  Use a truncstore if the input value is
1726   // later than DestVT.
1727   SDValue Store;
1728 
1729   if (SrcSize > SlotSize)
1730     Store = DAG.getTruncStore(DAG.getEntryNode(), dl, SrcOp, FIPtr, PtrInfo,
1731                               SlotVT, SrcAlign);
1732   else {
1733     assert(SrcSize == SlotSize && "Invalid store");
1734     Store =
1735         DAG.getStore(DAG.getEntryNode(), dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1736   }
1737 
1738   // Result is a load from the stack slot.
1739   if (SlotSize == DestSize)
1740     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1741 
1742   assert(SlotSize < DestSize && "Unknown extension!");
1743   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1744                         DestAlign);
1745 }
1746 
1747 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1748   SDLoc dl(Node);
1749   // Create a vector sized/aligned stack slot, store the value to element #0,
1750   // then load the whole vector back out.
1751   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1752 
1753   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1754   int SPFI = StackPtrFI->getIndex();
1755 
1756   SDValue Ch = DAG.getTruncStore(
1757       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1758       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1759       Node->getValueType(0).getVectorElementType());
1760   return DAG.getLoad(
1761       Node->getValueType(0), dl, Ch, StackPtr,
1762       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1763 }
1764 
1765 static bool
1766 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1767                      const TargetLowering &TLI, SDValue &Res) {
1768   unsigned NumElems = Node->getNumOperands();
1769   SDLoc dl(Node);
1770   EVT VT = Node->getValueType(0);
1771 
1772   // Try to group the scalars into pairs, shuffle the pairs together, then
1773   // shuffle the pairs of pairs together, etc. until the vector has
1774   // been built. This will work only if all of the necessary shuffle masks
1775   // are legal.
1776 
1777   // We do this in two phases; first to check the legality of the shuffles,
1778   // and next, assuming that all shuffles are legal, to create the new nodes.
1779   for (int Phase = 0; Phase < 2; ++Phase) {
1780     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1781                                                               NewIntermedVals;
1782     for (unsigned i = 0; i < NumElems; ++i) {
1783       SDValue V = Node->getOperand(i);
1784       if (V.isUndef())
1785         continue;
1786 
1787       SDValue Vec;
1788       if (Phase)
1789         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1790       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1791     }
1792 
1793     while (IntermedVals.size() > 2) {
1794       NewIntermedVals.clear();
1795       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1796         // This vector and the next vector are shuffled together (simply to
1797         // append the one to the other).
1798         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1799 
1800         SmallVector<int, 16> FinalIndices;
1801         FinalIndices.reserve(IntermedVals[i].second.size() +
1802                              IntermedVals[i+1].second.size());
1803 
1804         int k = 0;
1805         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1806              ++j, ++k) {
1807           ShuffleVec[k] = j;
1808           FinalIndices.push_back(IntermedVals[i].second[j]);
1809         }
1810         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1811              ++j, ++k) {
1812           ShuffleVec[k] = NumElems + j;
1813           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1814         }
1815 
1816         SDValue Shuffle;
1817         if (Phase)
1818           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1819                                          IntermedVals[i+1].first,
1820                                          ShuffleVec);
1821         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1822           return false;
1823         NewIntermedVals.push_back(
1824             std::make_pair(Shuffle, std::move(FinalIndices)));
1825       }
1826 
1827       // If we had an odd number of defined values, then append the last
1828       // element to the array of new vectors.
1829       if ((IntermedVals.size() & 1) != 0)
1830         NewIntermedVals.push_back(IntermedVals.back());
1831 
1832       IntermedVals.swap(NewIntermedVals);
1833     }
1834 
1835     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1836            "Invalid number of intermediate vectors");
1837     SDValue Vec1 = IntermedVals[0].first;
1838     SDValue Vec2;
1839     if (IntermedVals.size() > 1)
1840       Vec2 = IntermedVals[1].first;
1841     else if (Phase)
1842       Vec2 = DAG.getUNDEF(VT);
1843 
1844     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1845     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1846       ShuffleVec[IntermedVals[0].second[i]] = i;
1847     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1848       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1849 
1850     if (Phase)
1851       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1852     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1853       return false;
1854   }
1855 
1856   return true;
1857 }
1858 
1859 /// Expand a BUILD_VECTOR node on targets that don't
1860 /// support the operation, but do support the resultant vector type.
1861 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1862   unsigned NumElems = Node->getNumOperands();
1863   SDValue Value1, Value2;
1864   SDLoc dl(Node);
1865   EVT VT = Node->getValueType(0);
1866   EVT OpVT = Node->getOperand(0).getValueType();
1867   EVT EltVT = VT.getVectorElementType();
1868 
1869   // If the only non-undef value is the low element, turn this into a
1870   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1871   bool isOnlyLowElement = true;
1872   bool MoreThanTwoValues = false;
1873   bool isConstant = true;
1874   for (unsigned i = 0; i < NumElems; ++i) {
1875     SDValue V = Node->getOperand(i);
1876     if (V.isUndef())
1877       continue;
1878     if (i > 0)
1879       isOnlyLowElement = false;
1880     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1881       isConstant = false;
1882 
1883     if (!Value1.getNode()) {
1884       Value1 = V;
1885     } else if (!Value2.getNode()) {
1886       if (V != Value1)
1887         Value2 = V;
1888     } else if (V != Value1 && V != Value2) {
1889       MoreThanTwoValues = true;
1890     }
1891   }
1892 
1893   if (!Value1.getNode())
1894     return DAG.getUNDEF(VT);
1895 
1896   if (isOnlyLowElement)
1897     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1898 
1899   // If all elements are constants, create a load from the constant pool.
1900   if (isConstant) {
1901     SmallVector<Constant*, 16> CV;
1902     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1903       if (ConstantFPSDNode *V =
1904           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1905         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1906       } else if (ConstantSDNode *V =
1907                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1908         if (OpVT==EltVT)
1909           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1910         else {
1911           // If OpVT and EltVT don't match, EltVT is not legal and the
1912           // element values have been promoted/truncated earlier.  Undo this;
1913           // we don't want a v16i8 to become a v16i32 for example.
1914           const ConstantInt *CI = V->getConstantIntValue();
1915           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1916                                         CI->getZExtValue()));
1917         }
1918       } else {
1919         assert(Node->getOperand(i).isUndef());
1920         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1921         CV.push_back(UndefValue::get(OpNTy));
1922       }
1923     }
1924     Constant *CP = ConstantVector::get(CV);
1925     SDValue CPIdx =
1926         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1927     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
1928     return DAG.getLoad(
1929         VT, dl, DAG.getEntryNode(), CPIdx,
1930         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1931         Alignment);
1932   }
1933 
1934   SmallSet<SDValue, 16> DefinedValues;
1935   for (unsigned i = 0; i < NumElems; ++i) {
1936     if (Node->getOperand(i).isUndef())
1937       continue;
1938     DefinedValues.insert(Node->getOperand(i));
1939   }
1940 
1941   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1942     if (!MoreThanTwoValues) {
1943       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1944       for (unsigned i = 0; i < NumElems; ++i) {
1945         SDValue V = Node->getOperand(i);
1946         if (V.isUndef())
1947           continue;
1948         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1949       }
1950       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1951         // Get the splatted value into the low element of a vector register.
1952         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1953         SDValue Vec2;
1954         if (Value2.getNode())
1955           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
1956         else
1957           Vec2 = DAG.getUNDEF(VT);
1958 
1959         // Return shuffle(LowValVec, undef, <0,0,0,0>)
1960         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1961       }
1962     } else {
1963       SDValue Res;
1964       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
1965         return Res;
1966     }
1967   }
1968 
1969   // Otherwise, we can't handle this case efficiently.
1970   return ExpandVectorBuildThroughStack(Node);
1971 }
1972 
1973 // Expand a node into a call to a libcall.  If the result value
1974 // does not fit into a register, return the lo part and set the hi part to the
1975 // by-reg argument.  If it does fit into a single register, return the result
1976 // and leave the Hi part unset.
1977 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
1978                                             bool isSigned) {
1979   TargetLowering::ArgListTy Args;
1980   TargetLowering::ArgListEntry Entry;
1981   for (const SDValue &Op : Node->op_values()) {
1982     EVT ArgVT = Op.getValueType();
1983     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1984     Entry.Node = Op;
1985     Entry.Ty = ArgTy;
1986     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
1987     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
1988     Args.push_back(Entry);
1989   }
1990   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1991                                          TLI.getPointerTy(DAG.getDataLayout()));
1992 
1993   EVT RetVT = Node->getValueType(0);
1994   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
1995 
1996   // By default, the input chain to this libcall is the entry node of the
1997   // function. If the libcall is going to be emitted as a tail call then
1998   // TLI.isUsedByReturnOnly will change it to the right chain if the return
1999   // node which is being folded has a non-entry input chain.
2000   SDValue InChain = DAG.getEntryNode();
2001 
2002   // isTailCall may be true since the callee does not reference caller stack
2003   // frame. Check if it's in the right position and that the return types match.
2004   SDValue TCChain = InChain;
2005   const Function &F = DAG.getMachineFunction().getFunction();
2006   bool isTailCall =
2007       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2008       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2009   if (isTailCall)
2010     InChain = TCChain;
2011 
2012   TargetLowering::CallLoweringInfo CLI(DAG);
2013   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2014   CLI.setDebugLoc(SDLoc(Node))
2015       .setChain(InChain)
2016       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2017                     std::move(Args))
2018       .setTailCall(isTailCall)
2019       .setSExtResult(signExtend)
2020       .setZExtResult(!signExtend)
2021       .setIsPostTypeLegalization(true);
2022 
2023   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2024 
2025   if (!CallInfo.second.getNode()) {
2026     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump());
2027     // It's a tailcall, return the chain (which is the DAG root).
2028     return DAG.getRoot();
2029   }
2030 
2031   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump());
2032   return CallInfo.first;
2033 }
2034 
2035 /// Generate a libcall taking the given operands as arguments
2036 /// and returning a result of type RetVT.
2037 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, EVT RetVT,
2038                                             const SDValue *Ops, unsigned NumOps,
2039                                             bool isSigned, const SDLoc &dl) {
2040   TargetLowering::ArgListTy Args;
2041   Args.reserve(NumOps);
2042 
2043   TargetLowering::ArgListEntry Entry;
2044   for (unsigned i = 0; i != NumOps; ++i) {
2045     Entry.Node = Ops[i];
2046     Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
2047     Entry.IsSExt = isSigned;
2048     Entry.IsZExt = !isSigned;
2049     Args.push_back(Entry);
2050   }
2051   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2052                                          TLI.getPointerTy(DAG.getDataLayout()));
2053 
2054   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2055 
2056   TargetLowering::CallLoweringInfo CLI(DAG);
2057   CLI.setDebugLoc(dl)
2058       .setChain(DAG.getEntryNode())
2059       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2060                     std::move(Args))
2061       .setSExtResult(isSigned)
2062       .setZExtResult(!isSigned)
2063       .setIsPostTypeLegalization(true);
2064 
2065   std::pair<SDValue,SDValue> CallInfo = TLI.LowerCallTo(CLI);
2066 
2067   return CallInfo.first;
2068 }
2069 
2070 // Expand a node into a call to a libcall. Similar to
2071 // ExpandLibCall except that the first operand is the in-chain.
2072 std::pair<SDValue, SDValue>
2073 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
2074                                          SDNode *Node,
2075                                          bool isSigned) {
2076   SDValue InChain = Node->getOperand(0);
2077 
2078   TargetLowering::ArgListTy Args;
2079   TargetLowering::ArgListEntry Entry;
2080   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
2081     EVT ArgVT = Node->getOperand(i).getValueType();
2082     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2083     Entry.Node = Node->getOperand(i);
2084     Entry.Ty = ArgTy;
2085     Entry.IsSExt = isSigned;
2086     Entry.IsZExt = !isSigned;
2087     Args.push_back(Entry);
2088   }
2089   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2090                                          TLI.getPointerTy(DAG.getDataLayout()));
2091 
2092   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
2093 
2094   TargetLowering::CallLoweringInfo CLI(DAG);
2095   CLI.setDebugLoc(SDLoc(Node))
2096       .setChain(InChain)
2097       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2098                     std::move(Args))
2099       .setSExtResult(isSigned)
2100       .setZExtResult(!isSigned);
2101 
2102   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2103 
2104   return CallInfo;
2105 }
2106 
2107 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2108                                               RTLIB::Libcall Call_F32,
2109                                               RTLIB::Libcall Call_F64,
2110                                               RTLIB::Libcall Call_F80,
2111                                               RTLIB::Libcall Call_F128,
2112                                               RTLIB::Libcall Call_PPCF128) {
2113   if (Node->isStrictFPOpcode())
2114     Node = DAG.mutateStrictFPToFP(Node);
2115 
2116   RTLIB::Libcall LC;
2117   switch (Node->getSimpleValueType(0).SimpleTy) {
2118   default: llvm_unreachable("Unexpected request for libcall!");
2119   case MVT::f32: LC = Call_F32; break;
2120   case MVT::f64: LC = Call_F64; break;
2121   case MVT::f80: LC = Call_F80; break;
2122   case MVT::f128: LC = Call_F128; break;
2123   case MVT::ppcf128: LC = Call_PPCF128; break;
2124   }
2125   return ExpandLibCall(LC, Node, false);
2126 }
2127 
2128 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2129                                                RTLIB::Libcall Call_I8,
2130                                                RTLIB::Libcall Call_I16,
2131                                                RTLIB::Libcall Call_I32,
2132                                                RTLIB::Libcall Call_I64,
2133                                                RTLIB::Libcall Call_I128) {
2134   RTLIB::Libcall LC;
2135   switch (Node->getSimpleValueType(0).SimpleTy) {
2136   default: llvm_unreachable("Unexpected request for libcall!");
2137   case MVT::i8:   LC = Call_I8; break;
2138   case MVT::i16:  LC = Call_I16; break;
2139   case MVT::i32:  LC = Call_I32; break;
2140   case MVT::i64:  LC = Call_I64; break;
2141   case MVT::i128: LC = Call_I128; break;
2142   }
2143   return ExpandLibCall(LC, Node, isSigned);
2144 }
2145 
2146 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2147 void
2148 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2149                                           SmallVectorImpl<SDValue> &Results) {
2150   unsigned Opcode = Node->getOpcode();
2151   bool isSigned = Opcode == ISD::SDIVREM;
2152 
2153   RTLIB::Libcall LC;
2154   switch (Node->getSimpleValueType(0).SimpleTy) {
2155   default: llvm_unreachable("Unexpected request for libcall!");
2156   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2157   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2158   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2159   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2160   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2161   }
2162 
2163   // The input chain to this libcall is the entry node of the function.
2164   // Legalizing the call will automatically add the previous call to the
2165   // dependence.
2166   SDValue InChain = DAG.getEntryNode();
2167 
2168   EVT RetVT = Node->getValueType(0);
2169   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2170 
2171   TargetLowering::ArgListTy Args;
2172   TargetLowering::ArgListEntry Entry;
2173   for (const SDValue &Op : Node->op_values()) {
2174     EVT ArgVT = Op.getValueType();
2175     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2176     Entry.Node = Op;
2177     Entry.Ty = ArgTy;
2178     Entry.IsSExt = isSigned;
2179     Entry.IsZExt = !isSigned;
2180     Args.push_back(Entry);
2181   }
2182 
2183   // Also pass the return address of the remainder.
2184   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2185   Entry.Node = FIPtr;
2186   Entry.Ty = RetTy->getPointerTo();
2187   Entry.IsSExt = isSigned;
2188   Entry.IsZExt = !isSigned;
2189   Args.push_back(Entry);
2190 
2191   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2192                                          TLI.getPointerTy(DAG.getDataLayout()));
2193 
2194   SDLoc dl(Node);
2195   TargetLowering::CallLoweringInfo CLI(DAG);
2196   CLI.setDebugLoc(dl)
2197       .setChain(InChain)
2198       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2199                     std::move(Args))
2200       .setSExtResult(isSigned)
2201       .setZExtResult(!isSigned);
2202 
2203   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2204 
2205   // Remainder is loaded back from the stack frame.
2206   SDValue Rem =
2207       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2208   Results.push_back(CallInfo.first);
2209   Results.push_back(Rem);
2210 }
2211 
2212 /// Return true if sincos libcall is available.
2213 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2214   RTLIB::Libcall LC;
2215   switch (Node->getSimpleValueType(0).SimpleTy) {
2216   default: llvm_unreachable("Unexpected request for libcall!");
2217   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2218   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2219   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2220   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2221   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2222   }
2223   return TLI.getLibcallName(LC) != nullptr;
2224 }
2225 
2226 /// Only issue sincos libcall if both sin and cos are needed.
2227 static bool useSinCos(SDNode *Node) {
2228   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2229     ? ISD::FCOS : ISD::FSIN;
2230 
2231   SDValue Op0 = Node->getOperand(0);
2232   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2233        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2234     SDNode *User = *UI;
2235     if (User == Node)
2236       continue;
2237     // The other user might have been turned into sincos already.
2238     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2239       return true;
2240   }
2241   return false;
2242 }
2243 
2244 /// Issue libcalls to sincos to compute sin / cos pairs.
2245 void
2246 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2247                                           SmallVectorImpl<SDValue> &Results) {
2248   RTLIB::Libcall LC;
2249   switch (Node->getSimpleValueType(0).SimpleTy) {
2250   default: llvm_unreachable("Unexpected request for libcall!");
2251   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2252   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2253   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2254   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2255   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2256   }
2257 
2258   // The input chain to this libcall is the entry node of the function.
2259   // Legalizing the call will automatically add the previous call to the
2260   // dependence.
2261   SDValue InChain = DAG.getEntryNode();
2262 
2263   EVT RetVT = Node->getValueType(0);
2264   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2265 
2266   TargetLowering::ArgListTy Args;
2267   TargetLowering::ArgListEntry Entry;
2268 
2269   // Pass the argument.
2270   Entry.Node = Node->getOperand(0);
2271   Entry.Ty = RetTy;
2272   Entry.IsSExt = false;
2273   Entry.IsZExt = false;
2274   Args.push_back(Entry);
2275 
2276   // Pass the return address of sin.
2277   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2278   Entry.Node = SinPtr;
2279   Entry.Ty = RetTy->getPointerTo();
2280   Entry.IsSExt = false;
2281   Entry.IsZExt = false;
2282   Args.push_back(Entry);
2283 
2284   // Also pass the return address of the cos.
2285   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2286   Entry.Node = CosPtr;
2287   Entry.Ty = RetTy->getPointerTo();
2288   Entry.IsSExt = false;
2289   Entry.IsZExt = false;
2290   Args.push_back(Entry);
2291 
2292   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2293                                          TLI.getPointerTy(DAG.getDataLayout()));
2294 
2295   SDLoc dl(Node);
2296   TargetLowering::CallLoweringInfo CLI(DAG);
2297   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2298       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2299       std::move(Args));
2300 
2301   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2302 
2303   Results.push_back(
2304       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2305   Results.push_back(
2306       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2307 }
2308 
2309 /// This function is responsible for legalizing a
2310 /// INT_TO_FP operation of the specified operand when the target requests that
2311 /// we expand it.  At this point, we know that the result and operand types are
2312 /// legal for the target.
2313 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0,
2314                                                    EVT DestVT,
2315                                                    const SDLoc &dl) {
2316   EVT SrcVT = Op0.getValueType();
2317   EVT ShiftVT = TLI.getShiftAmountTy(SrcVT, DAG.getDataLayout());
2318 
2319   // TODO: Should any fast-math-flags be set for the created nodes?
2320   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2321   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2322     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2323                          "expansion\n");
2324 
2325     // Get the stack frame index of a 8 byte buffer.
2326     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2327 
2328     // word offset constant for Hi/Lo address computation
2329     SDValue WordOff = DAG.getConstant(sizeof(int), dl,
2330                                       StackSlot.getValueType());
2331     // set up Hi and Lo (into buffer) address based on endian
2332     SDValue Hi = StackSlot;
2333     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
2334                              StackSlot, WordOff);
2335     if (DAG.getDataLayout().isLittleEndian())
2336       std::swap(Hi, Lo);
2337 
2338     // if signed map to unsigned space
2339     SDValue Op0Mapped;
2340     if (isSigned) {
2341       // constant used to invert sign bit (signed to unsigned mapping)
2342       SDValue SignBit = DAG.getConstant(0x80000000u, dl, MVT::i32);
2343       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
2344     } else {
2345       Op0Mapped = Op0;
2346     }
2347     // store the lo of the constructed double - based on integer input
2348     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl, Op0Mapped, Lo,
2349                                   MachinePointerInfo());
2350     // initial hi portion of constructed double
2351     SDValue InitialHi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2352     // store the hi of the constructed double - biased exponent
2353     SDValue Store2 =
2354         DAG.getStore(Store1, dl, InitialHi, Hi, MachinePointerInfo());
2355     // load the constructed double
2356     SDValue Load =
2357         DAG.getLoad(MVT::f64, dl, Store2, StackSlot, MachinePointerInfo());
2358     // FP constant to bias correct the final result
2359     SDValue Bias = DAG.getConstantFP(isSigned ?
2360                                      BitsToDouble(0x4330000080000000ULL) :
2361                                      BitsToDouble(0x4330000000000000ULL),
2362                                      dl, MVT::f64);
2363     // subtract the bias
2364     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2365     // final result
2366     SDValue Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2367     return Result;
2368   }
2369   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2370   // Code below here assumes !isSigned without checking again.
2371 
2372   // Implementation of unsigned i64 to f64 following the algorithm in
2373   // __floatundidf in compiler_rt. This implementation has the advantage
2374   // of performing rounding correctly, both in the default rounding mode
2375   // and in all alternate rounding modes.
2376   // TODO: Generalize this for use with other types.
2377   if (SrcVT == MVT::i64 && DestVT == MVT::f64) {
2378     LLVM_DEBUG(dbgs() << "Converting unsigned i64 to f64\n");
2379     SDValue TwoP52 = DAG.getConstant(UINT64_C(0x4330000000000000), dl, SrcVT);
2380     SDValue TwoP84PlusTwoP52 = DAG.getConstantFP(
2381         BitsToDouble(UINT64_C(0x4530000000100000)), dl, DestVT);
2382     SDValue TwoP84 = DAG.getConstant(UINT64_C(0x4530000000000000), dl, SrcVT);
2383     SDValue LoMask = DAG.getConstant(UINT64_C(0x00000000FFFFFFFF), dl, SrcVT);
2384     SDValue HiShift = DAG.getConstant(32, dl, ShiftVT);
2385 
2386     SDValue Lo = DAG.getNode(ISD::AND, dl, SrcVT, Op0, LoMask);
2387     SDValue Hi = DAG.getNode(ISD::SRL, dl, SrcVT, Op0, HiShift);
2388     SDValue LoOr = DAG.getNode(ISD::OR, dl, SrcVT, Lo, TwoP52);
2389     SDValue HiOr = DAG.getNode(ISD::OR, dl, SrcVT, Hi, TwoP84);
2390     SDValue LoFlt = DAG.getNode(ISD::BITCAST, dl, DestVT, LoOr);
2391     SDValue HiFlt = DAG.getNode(ISD::BITCAST, dl, DestVT, HiOr);
2392     SDValue HiSub = DAG.getNode(ISD::FSUB, dl, DestVT, HiFlt, TwoP84PlusTwoP52);
2393     return DAG.getNode(ISD::FADD, dl, DestVT, LoFlt, HiSub);
2394   }
2395 
2396   // TODO: Generalize this for use with other types.
2397   if (SrcVT == MVT::i64 && DestVT == MVT::f32) {
2398     LLVM_DEBUG(dbgs() << "Converting unsigned i64 to f32\n");
2399     // For unsigned conversions, convert them to signed conversions using the
2400     // algorithm from the x86_64 __floatundidf in compiler_rt.
2401     if (!isSigned) {
2402       SDValue Fast = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Op0);
2403 
2404       SDValue ShiftConst = DAG.getConstant(1, dl, ShiftVT);
2405       SDValue Shr = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0, ShiftConst);
2406       SDValue AndConst = DAG.getConstant(1, dl, MVT::i64);
2407       SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0, AndConst);
2408       SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And, Shr);
2409 
2410       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Or);
2411       SDValue Slow = DAG.getNode(ISD::FADD, dl, MVT::f32, SignCvt, SignCvt);
2412 
2413       // TODO: This really should be implemented using a branch rather than a
2414       // select.  We happen to get lucky and machinesink does the right
2415       // thing most of the time.  This would be a good candidate for a
2416       //pseudo-op, or, even better, for whole-function isel.
2417       SDValue SignBitTest = DAG.getSetCC(dl, getSetCCResultType(MVT::i64),
2418         Op0, DAG.getConstant(0, dl, MVT::i64), ISD::SETLT);
2419       return DAG.getSelect(dl, MVT::f32, SignBitTest, Slow, Fast);
2420     }
2421 
2422     // Otherwise, implement the fully general conversion.
2423 
2424     SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
2425          DAG.getConstant(UINT64_C(0xfffffffffffff800), dl, MVT::i64));
2426     SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And,
2427          DAG.getConstant(UINT64_C(0x800), dl, MVT::i64));
2428     SDValue And2 = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
2429          DAG.getConstant(UINT64_C(0x7ff), dl, MVT::i64));
2430     SDValue Ne = DAG.getSetCC(dl, getSetCCResultType(MVT::i64), And2,
2431                               DAG.getConstant(UINT64_C(0), dl, MVT::i64),
2432                               ISD::SETNE);
2433     SDValue Sel = DAG.getSelect(dl, MVT::i64, Ne, Or, Op0);
2434     SDValue Ge = DAG.getSetCC(dl, getSetCCResultType(MVT::i64), Op0,
2435                               DAG.getConstant(UINT64_C(0x0020000000000000), dl,
2436                                               MVT::i64),
2437                               ISD::SETUGE);
2438     SDValue Sel2 = DAG.getSelect(dl, MVT::i64, Ge, Sel, Op0);
2439     EVT SHVT = TLI.getShiftAmountTy(Sel2.getValueType(), DAG.getDataLayout());
2440 
2441     SDValue Sh = DAG.getNode(ISD::SRL, dl, MVT::i64, Sel2,
2442                              DAG.getConstant(32, dl, SHVT));
2443     SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sh);
2444     SDValue Fcvt = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Trunc);
2445     SDValue TwoP32 =
2446       DAG.getConstantFP(BitsToDouble(UINT64_C(0x41f0000000000000)), dl,
2447                         MVT::f64);
2448     SDValue Fmul = DAG.getNode(ISD::FMUL, dl, MVT::f64, TwoP32, Fcvt);
2449     SDValue Lo = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sel2);
2450     SDValue Fcvt2 = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Lo);
2451     SDValue Fadd = DAG.getNode(ISD::FADD, dl, MVT::f64, Fmul, Fcvt2);
2452     return DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Fadd,
2453                        DAG.getIntPtrConstant(0, dl));
2454   }
2455 
2456   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2457 
2458   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2459                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2460   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2461           Four = DAG.getIntPtrConstant(4, dl);
2462   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2463                                     SignSet, Four, Zero);
2464 
2465   // If the sign bit of the integer is set, the large number will be treated
2466   // as a negative number.  To counteract this, the dynamic code adds an
2467   // offset depending on the data type.
2468   uint64_t FF;
2469   switch (SrcVT.getSimpleVT().SimpleTy) {
2470   default: llvm_unreachable("Unsupported integer type!");
2471   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2472   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2473   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2474   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2475   }
2476   if (DAG.getDataLayout().isLittleEndian())
2477     FF <<= 32;
2478   Constant *FudgeFactor = ConstantInt::get(
2479                                        Type::getInt64Ty(*DAG.getContext()), FF);
2480 
2481   SDValue CPIdx =
2482       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2483   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
2484   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2485   Alignment = std::min(Alignment, 4u);
2486   SDValue FudgeInReg;
2487   if (DestVT == MVT::f32)
2488     FudgeInReg = DAG.getLoad(
2489         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2490         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2491         Alignment);
2492   else {
2493     SDValue Load = DAG.getExtLoad(
2494         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2495         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2496         Alignment);
2497     HandleSDNode Handle(Load);
2498     LegalizeOp(Load.getNode());
2499     FudgeInReg = Handle.getValue();
2500   }
2501 
2502   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2503 }
2504 
2505 /// This function is responsible for legalizing a
2506 /// *INT_TO_FP operation of the specified operand when the target requests that
2507 /// we promote it.  At this point, we know that the result and operand types are
2508 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2509 /// operation that takes a larger input.
2510 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT,
2511                                                     bool isSigned,
2512                                                     const SDLoc &dl) {
2513   // First step, figure out the appropriate *INT_TO_FP operation to use.
2514   EVT NewInTy = LegalOp.getValueType();
2515 
2516   unsigned OpToUse = 0;
2517 
2518   // Scan for the appropriate larger type to use.
2519   while (true) {
2520     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2521     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2522 
2523     // If the target supports SINT_TO_FP of this type, use it.
2524     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
2525       OpToUse = ISD::SINT_TO_FP;
2526       break;
2527     }
2528     if (isSigned) continue;
2529 
2530     // If the target supports UINT_TO_FP of this type, use it.
2531     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
2532       OpToUse = ISD::UINT_TO_FP;
2533       break;
2534     }
2535 
2536     // Otherwise, try a larger type.
2537   }
2538 
2539   // Okay, we found the operation and type to use.  Zero extend our input to the
2540   // desired type then run the operation on it.
2541   return DAG.getNode(OpToUse, dl, DestVT,
2542                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2543                                  dl, NewInTy, LegalOp));
2544 }
2545 
2546 /// This function is responsible for legalizing a
2547 /// FP_TO_*INT operation of the specified operand when the target requests that
2548 /// we promote it.  At this point, we know that the result and operand types are
2549 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2550 /// operation that returns a larger result.
2551 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT,
2552                                                     bool isSigned,
2553                                                     const SDLoc &dl) {
2554   // First step, figure out the appropriate FP_TO*INT operation to use.
2555   EVT NewOutTy = DestVT;
2556 
2557   unsigned OpToUse = 0;
2558 
2559   // Scan for the appropriate larger type to use.
2560   while (true) {
2561     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2562     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2563 
2564     // A larger signed type can hold all unsigned values of the requested type,
2565     // so using FP_TO_SINT is valid
2566     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
2567       OpToUse = ISD::FP_TO_SINT;
2568       break;
2569     }
2570 
2571     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2572     if (!isSigned && TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
2573       OpToUse = ISD::FP_TO_UINT;
2574       break;
2575     }
2576 
2577     // Otherwise, try a larger type.
2578   }
2579 
2580   // Okay, we found the operation and type to use.
2581   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2582 
2583   // Truncate the result of the extended FP_TO_*INT operation to the desired
2584   // size.
2585   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2586 }
2587 
2588 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
2589 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2590   EVT VT = Op.getValueType();
2591   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2592   unsigned Sz = VT.getScalarSizeInBits();
2593 
2594   SDValue Tmp, Tmp2, Tmp3;
2595 
2596   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2597   // and finally the i1 pairs.
2598   // TODO: We can easily support i4/i2 legal types if any target ever does.
2599   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2600     // Create the masks - repeating the pattern every byte.
2601     APInt MaskHi4(Sz, 0), MaskHi2(Sz, 0), MaskHi1(Sz, 0);
2602     APInt MaskLo4(Sz, 0), MaskLo2(Sz, 0), MaskLo1(Sz, 0);
2603     for (unsigned J = 0; J != Sz; J += 8) {
2604       MaskHi4 = MaskHi4 | (0xF0ull << J);
2605       MaskLo4 = MaskLo4 | (0x0Full << J);
2606       MaskHi2 = MaskHi2 | (0xCCull << J);
2607       MaskLo2 = MaskLo2 | (0x33ull << J);
2608       MaskHi1 = MaskHi1 | (0xAAull << J);
2609       MaskLo1 = MaskLo1 | (0x55ull << J);
2610     }
2611 
2612     // BSWAP if the type is wider than a single byte.
2613     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2614 
2615     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2616     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2617     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2618     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, VT));
2619     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, VT));
2620     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2621 
2622     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2623     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2624     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2625     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, VT));
2626     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, VT));
2627     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2628 
2629     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2630     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2631     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2632     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, VT));
2633     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, VT));
2634     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2635     return Tmp;
2636   }
2637 
2638   Tmp = DAG.getConstant(0, dl, VT);
2639   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2640     if (I < J)
2641       Tmp2 =
2642           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2643     else
2644       Tmp2 =
2645           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2646 
2647     APInt Shift(Sz, 1);
2648     Shift <<= J;
2649     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2650     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2651   }
2652 
2653   return Tmp;
2654 }
2655 
2656 /// Open code the operations for BSWAP of the specified operation.
2657 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2658   EVT VT = Op.getValueType();
2659   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2660   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2661   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2662   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2663   case MVT::i16:
2664     Tmp2 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2665     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2666     return DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2667   case MVT::i32:
2668     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2669     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2670     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2671     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2672     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2673                        DAG.getConstant(0xFF0000, dl, VT));
2674     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2675     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2676     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2677     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2678   case MVT::i64:
2679     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2680     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2681     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2682     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2683     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2684     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2685     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2686     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2687     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2688                        DAG.getConstant(255ULL<<48, dl, VT));
2689     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2690                        DAG.getConstant(255ULL<<40, dl, VT));
2691     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2692                        DAG.getConstant(255ULL<<32, dl, VT));
2693     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2694                        DAG.getConstant(255ULL<<24, dl, VT));
2695     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2696                        DAG.getConstant(255ULL<<16, dl, VT));
2697     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2698                        DAG.getConstant(255ULL<<8 , dl, VT));
2699     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2700     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2701     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2702     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2703     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2704     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2705     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2706   }
2707 }
2708 
2709 /// Expand the specified bitcount instruction into operations.
2710 SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
2711                                              const SDLoc &dl) {
2712   EVT VT = Op.getValueType();
2713   EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2714   unsigned Len = VT.getScalarSizeInBits();
2715 
2716   switch (Opc) {
2717   default: llvm_unreachable("Cannot expand this yet!");
2718   case ISD::CTPOP: {
2719     assert(VT.isInteger() && Len <= 128 && Len % 8 == 0 &&
2720            "CTPOP not implemented for this type.");
2721 
2722     // This is the "best" algorithm from
2723     // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
2724 
2725     SDValue Mask55 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x55)),
2726                                      dl, VT);
2727     SDValue Mask33 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x33)),
2728                                      dl, VT);
2729     SDValue Mask0F = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x0F)),
2730                                      dl, VT);
2731     SDValue Mask01 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x01)),
2732                                      dl, VT);
2733 
2734     // v = v - ((v >> 1) & 0x55555555...)
2735     Op = DAG.getNode(ISD::SUB, dl, VT, Op,
2736                      DAG.getNode(ISD::AND, dl, VT,
2737                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2738                                              DAG.getConstant(1, dl, ShVT)),
2739                                  Mask55));
2740     // v = (v & 0x33333333...) + ((v >> 2) & 0x33333333...)
2741     Op = DAG.getNode(ISD::ADD, dl, VT,
2742                      DAG.getNode(ISD::AND, dl, VT, Op, Mask33),
2743                      DAG.getNode(ISD::AND, dl, VT,
2744                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2745                                              DAG.getConstant(2, dl, ShVT)),
2746                                  Mask33));
2747     // v = (v + (v >> 4)) & 0x0F0F0F0F...
2748     Op = DAG.getNode(ISD::AND, dl, VT,
2749                      DAG.getNode(ISD::ADD, dl, VT, Op,
2750                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2751                                              DAG.getConstant(4, dl, ShVT))),
2752                      Mask0F);
2753     // v = (v * 0x01010101...) >> (Len - 8)
2754     if (Len > 8)
2755       Op = DAG.getNode(ISD::SRL, dl, VT,
2756                        DAG.getNode(ISD::MUL, dl, VT, Op, Mask01),
2757                        DAG.getConstant(Len - 8, dl, ShVT));
2758 
2759     return Op;
2760   }
2761   case ISD::CTLZ_ZERO_UNDEF:
2762     // This trivially expands to CTLZ.
2763     return DAG.getNode(ISD::CTLZ, dl, VT, Op);
2764   case ISD::CTLZ: {
2765     if (TLI.isOperationLegalOrCustom(ISD::CTLZ_ZERO_UNDEF, VT)) {
2766       EVT SetCCVT = getSetCCResultType(VT);
2767       SDValue CTLZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, dl, VT, Op);
2768       SDValue Zero = DAG.getConstant(0, dl, VT);
2769       SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ);
2770       return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero,
2771                          DAG.getConstant(Len, dl, VT), CTLZ);
2772     }
2773 
2774     // for now, we do this:
2775     // x = x | (x >> 1);
2776     // x = x | (x >> 2);
2777     // ...
2778     // x = x | (x >>16);
2779     // x = x | (x >>32); // for 64-bit input
2780     // return popcount(~x);
2781     //
2782     // Ref: "Hacker's Delight" by Henry Warren
2783     for (unsigned i = 0; (1U << i) <= (Len / 2); ++i) {
2784       SDValue Tmp3 = DAG.getConstant(1ULL << i, dl, ShVT);
2785       Op = DAG.getNode(ISD::OR, dl, VT, Op,
2786                        DAG.getNode(ISD::SRL, dl, VT, Op, Tmp3));
2787     }
2788     Op = DAG.getNOT(dl, Op, VT);
2789     return DAG.getNode(ISD::CTPOP, dl, VT, Op);
2790   }
2791   case ISD::CTTZ_ZERO_UNDEF:
2792     // This trivially expands to CTTZ.
2793     return DAG.getNode(ISD::CTTZ, dl, VT, Op);
2794   case ISD::CTTZ: {
2795     if (TLI.isOperationLegalOrCustom(ISD::CTTZ_ZERO_UNDEF, VT)) {
2796       EVT SetCCVT = getSetCCResultType(VT);
2797       SDValue CTTZ = DAG.getNode(ISD::CTTZ_ZERO_UNDEF, dl, VT, Op);
2798       SDValue Zero = DAG.getConstant(0, dl, VT);
2799       SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ);
2800       return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero,
2801                          DAG.getConstant(Len, dl, VT), CTTZ);
2802     }
2803 
2804     // for now, we use: { return popcount(~x & (x - 1)); }
2805     // unless the target has ctlz but not ctpop, in which case we use:
2806     // { return 32 - nlz(~x & (x-1)); }
2807     // Ref: "Hacker's Delight" by Henry Warren
2808     SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT,
2809                                DAG.getNOT(dl, Op, VT),
2810                                DAG.getNode(ISD::SUB, dl, VT, Op,
2811                                            DAG.getConstant(1, dl, VT)));
2812     // If ISD::CTLZ is legal and CTPOP isn't, then do that instead.
2813     if (!TLI.isOperationLegal(ISD::CTPOP, VT) &&
2814         TLI.isOperationLegal(ISD::CTLZ, VT))
2815       return DAG.getNode(ISD::SUB, dl, VT,
2816                          DAG.getConstant(Len, dl, VT),
2817                          DAG.getNode(ISD::CTLZ, dl, VT, Tmp3));
2818     return DAG.getNode(ISD::CTPOP, dl, VT, Tmp3);
2819   }
2820   }
2821 }
2822 
2823 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2824   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2825   SmallVector<SDValue, 8> Results;
2826   SDLoc dl(Node);
2827   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2828   bool NeedInvert;
2829   switch (Node->getOpcode()) {
2830   case ISD::CTPOP:
2831   case ISD::CTLZ:
2832   case ISD::CTLZ_ZERO_UNDEF:
2833   case ISD::CTTZ:
2834   case ISD::CTTZ_ZERO_UNDEF:
2835     Tmp1 = ExpandBitCount(Node->getOpcode(), Node->getOperand(0), dl);
2836     Results.push_back(Tmp1);
2837     break;
2838   case ISD::BITREVERSE:
2839     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2840     break;
2841   case ISD::BSWAP:
2842     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2843     break;
2844   case ISD::FRAMEADDR:
2845   case ISD::RETURNADDR:
2846   case ISD::FRAME_TO_ARGS_OFFSET:
2847     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2848     break;
2849   case ISD::EH_DWARF_CFA: {
2850     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2851                                         TLI.getPointerTy(DAG.getDataLayout()));
2852     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2853                                  CfaArg.getValueType(),
2854                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2855                                              CfaArg.getValueType()),
2856                                  CfaArg);
2857     SDValue FA = DAG.getNode(
2858         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2859         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2860     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2861                                   FA, Offset));
2862     break;
2863   }
2864   case ISD::FLT_ROUNDS_:
2865     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2866     break;
2867   case ISD::EH_RETURN:
2868   case ISD::EH_LABEL:
2869   case ISD::PREFETCH:
2870   case ISD::VAEND:
2871   case ISD::EH_SJLJ_LONGJMP:
2872     // If the target didn't expand these, there's nothing to do, so just
2873     // preserve the chain and be done.
2874     Results.push_back(Node->getOperand(0));
2875     break;
2876   case ISD::READCYCLECOUNTER:
2877     // If the target didn't expand this, just return 'zero' and preserve the
2878     // chain.
2879     Results.append(Node->getNumValues() - 1,
2880                    DAG.getConstant(0, dl, Node->getValueType(0)));
2881     Results.push_back(Node->getOperand(0));
2882     break;
2883   case ISD::EH_SJLJ_SETJMP:
2884     // If the target didn't expand this, just return 'zero' and preserve the
2885     // chain.
2886     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2887     Results.push_back(Node->getOperand(0));
2888     break;
2889   case ISD::ATOMIC_LOAD: {
2890     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2891     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2892     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2893     SDValue Swap = DAG.getAtomicCmpSwap(
2894         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2895         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2896         cast<AtomicSDNode>(Node)->getMemOperand());
2897     Results.push_back(Swap.getValue(0));
2898     Results.push_back(Swap.getValue(1));
2899     break;
2900   }
2901   case ISD::ATOMIC_STORE: {
2902     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2903     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2904                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2905                                  Node->getOperand(0),
2906                                  Node->getOperand(1), Node->getOperand(2),
2907                                  cast<AtomicSDNode>(Node)->getMemOperand());
2908     Results.push_back(Swap.getValue(1));
2909     break;
2910   }
2911   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2912     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2913     // splits out the success value as a comparison. Expanding the resulting
2914     // ATOMIC_CMP_SWAP will produce a libcall.
2915     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2916     SDValue Res = DAG.getAtomicCmpSwap(
2917         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2918         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2919         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2920 
2921     SDValue ExtRes = Res;
2922     SDValue LHS = Res;
2923     SDValue RHS = Node->getOperand(1);
2924 
2925     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2926     EVT OuterType = Node->getValueType(0);
2927     switch (TLI.getExtendForAtomicOps()) {
2928     case ISD::SIGN_EXTEND:
2929       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2930                         DAG.getValueType(AtomicType));
2931       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2932                         Node->getOperand(2), DAG.getValueType(AtomicType));
2933       ExtRes = LHS;
2934       break;
2935     case ISD::ZERO_EXTEND:
2936       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2937                         DAG.getValueType(AtomicType));
2938       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2939       ExtRes = LHS;
2940       break;
2941     case ISD::ANY_EXTEND:
2942       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2943       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2944       break;
2945     default:
2946       llvm_unreachable("Invalid atomic op extension");
2947     }
2948 
2949     SDValue Success =
2950         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2951 
2952     Results.push_back(ExtRes.getValue(0));
2953     Results.push_back(Success);
2954     Results.push_back(Res.getValue(1));
2955     break;
2956   }
2957   case ISD::DYNAMIC_STACKALLOC:
2958     ExpandDYNAMIC_STACKALLOC(Node, Results);
2959     break;
2960   case ISD::MERGE_VALUES:
2961     for (unsigned i = 0; i < Node->getNumValues(); i++)
2962       Results.push_back(Node->getOperand(i));
2963     break;
2964   case ISD::UNDEF: {
2965     EVT VT = Node->getValueType(0);
2966     if (VT.isInteger())
2967       Results.push_back(DAG.getConstant(0, dl, VT));
2968     else {
2969       assert(VT.isFloatingPoint() && "Unknown value type!");
2970       Results.push_back(DAG.getConstantFP(0, dl, VT));
2971     }
2972     break;
2973   }
2974   case ISD::FP_ROUND:
2975   case ISD::BITCAST:
2976     Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
2977                             Node->getValueType(0), dl);
2978     Results.push_back(Tmp1);
2979     break;
2980   case ISD::FP_EXTEND:
2981     Tmp1 = EmitStackConvert(Node->getOperand(0),
2982                             Node->getOperand(0).getValueType(),
2983                             Node->getValueType(0), dl);
2984     Results.push_back(Tmp1);
2985     break;
2986   case ISD::SIGN_EXTEND_INREG: {
2987     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2988     EVT VT = Node->getValueType(0);
2989 
2990     // An in-register sign-extend of a boolean is a negation:
2991     // 'true' (1) sign-extended is -1.
2992     // 'false' (0) sign-extended is 0.
2993     // However, we must mask the high bits of the source operand because the
2994     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
2995 
2996     // TODO: Do this for vectors too?
2997     if (ExtraVT.getSizeInBits() == 1) {
2998       SDValue One = DAG.getConstant(1, dl, VT);
2999       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
3000       SDValue Zero = DAG.getConstant(0, dl, VT);
3001       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
3002       Results.push_back(Neg);
3003       break;
3004     }
3005 
3006     // NOTE: we could fall back on load/store here too for targets without
3007     // SRA.  However, it is doubtful that any exist.
3008     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
3009     unsigned BitsDiff = VT.getScalarSizeInBits() -
3010                         ExtraVT.getScalarSizeInBits();
3011     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
3012     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
3013                        Node->getOperand(0), ShiftCst);
3014     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
3015     Results.push_back(Tmp1);
3016     break;
3017   }
3018   case ISD::FP_ROUND_INREG: {
3019     // The only way we can lower this is to turn it into a TRUNCSTORE,
3020     // EXTLOAD pair, targeting a temporary location (a stack slot).
3021 
3022     // NOTE: there is a choice here between constantly creating new stack
3023     // slots and always reusing the same one.  We currently always create
3024     // new ones, as reuse may inhibit scheduling.
3025     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
3026     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
3027                             Node->getValueType(0), dl);
3028     Results.push_back(Tmp1);
3029     break;
3030   }
3031   case ISD::SINT_TO_FP:
3032   case ISD::UINT_TO_FP:
3033     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
3034                                 Node->getOperand(0), Node->getValueType(0), dl);
3035     Results.push_back(Tmp1);
3036     break;
3037   case ISD::FP_TO_SINT:
3038     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
3039       Results.push_back(Tmp1);
3040     break;
3041   case ISD::FP_TO_UINT: {
3042     SDValue True, False;
3043     EVT VT =  Node->getOperand(0).getValueType();
3044     EVT NVT = Node->getValueType(0);
3045     APFloat apf(DAG.EVTToAPFloatSemantics(VT),
3046                 APInt::getNullValue(VT.getSizeInBits()));
3047     APInt x = APInt::getSignMask(NVT.getSizeInBits());
3048     (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
3049     Tmp1 = DAG.getConstantFP(apf, dl, VT);
3050     Tmp2 = DAG.getSetCC(dl, getSetCCResultType(VT),
3051                         Node->getOperand(0),
3052                         Tmp1, ISD::SETLT);
3053     True = DAG.getNode(ISD::FP_TO_SINT, dl, NVT, Node->getOperand(0));
3054     // TODO: Should any fast-math-flags be set for the FSUB?
3055     False = DAG.getNode(ISD::FP_TO_SINT, dl, NVT,
3056                         DAG.getNode(ISD::FSUB, dl, VT,
3057                                     Node->getOperand(0), Tmp1));
3058     False = DAG.getNode(ISD::XOR, dl, NVT, False,
3059                         DAG.getConstant(x, dl, NVT));
3060     Tmp1 = DAG.getSelect(dl, NVT, Tmp2, True, False);
3061     Results.push_back(Tmp1);
3062     break;
3063   }
3064   case ISD::VAARG:
3065     Results.push_back(DAG.expandVAArg(Node));
3066     Results.push_back(Results[0].getValue(1));
3067     break;
3068   case ISD::VACOPY:
3069     Results.push_back(DAG.expandVACopy(Node));
3070     break;
3071   case ISD::EXTRACT_VECTOR_ELT:
3072     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
3073       // This must be an access of the only element.  Return it.
3074       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
3075                          Node->getOperand(0));
3076     else
3077       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
3078     Results.push_back(Tmp1);
3079     break;
3080   case ISD::EXTRACT_SUBVECTOR:
3081     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
3082     break;
3083   case ISD::INSERT_SUBVECTOR:
3084     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3085     break;
3086   case ISD::CONCAT_VECTORS:
3087     Results.push_back(ExpandVectorBuildThroughStack(Node));
3088     break;
3089   case ISD::SCALAR_TO_VECTOR:
3090     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3091     break;
3092   case ISD::INSERT_VECTOR_ELT:
3093     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3094                                               Node->getOperand(1),
3095                                               Node->getOperand(2), dl));
3096     break;
3097   case ISD::VECTOR_SHUFFLE: {
3098     SmallVector<int, 32> NewMask;
3099     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3100 
3101     EVT VT = Node->getValueType(0);
3102     EVT EltVT = VT.getVectorElementType();
3103     SDValue Op0 = Node->getOperand(0);
3104     SDValue Op1 = Node->getOperand(1);
3105     if (!TLI.isTypeLegal(EltVT)) {
3106       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3107 
3108       // BUILD_VECTOR operands are allowed to be wider than the element type.
3109       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3110       // it.
3111       if (NewEltVT.bitsLT(EltVT)) {
3112         // Convert shuffle node.
3113         // If original node was v4i64 and the new EltVT is i32,
3114         // cast operands to v8i32 and re-build the mask.
3115 
3116         // Calculate new VT, the size of the new VT should be equal to original.
3117         EVT NewVT =
3118             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3119                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3120         assert(NewVT.bitsEq(VT));
3121 
3122         // cast operands to new VT
3123         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3124         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3125 
3126         // Convert the shuffle mask
3127         unsigned int factor =
3128                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3129 
3130         // EltVT gets smaller
3131         assert(factor > 0);
3132 
3133         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3134           if (Mask[i] < 0) {
3135             for (unsigned fi = 0; fi < factor; ++fi)
3136               NewMask.push_back(Mask[i]);
3137           }
3138           else {
3139             for (unsigned fi = 0; fi < factor; ++fi)
3140               NewMask.push_back(Mask[i]*factor+fi);
3141           }
3142         }
3143         Mask = NewMask;
3144         VT = NewVT;
3145       }
3146       EltVT = NewEltVT;
3147     }
3148     unsigned NumElems = VT.getVectorNumElements();
3149     SmallVector<SDValue, 16> Ops;
3150     for (unsigned i = 0; i != NumElems; ++i) {
3151       if (Mask[i] < 0) {
3152         Ops.push_back(DAG.getUNDEF(EltVT));
3153         continue;
3154       }
3155       unsigned Idx = Mask[i];
3156       if (Idx < NumElems)
3157         Ops.push_back(DAG.getNode(
3158             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3159             DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout()))));
3160       else
3161         Ops.push_back(DAG.getNode(
3162             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3163             DAG.getConstant(Idx - NumElems, dl,
3164                             TLI.getVectorIdxTy(DAG.getDataLayout()))));
3165     }
3166 
3167     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3168     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3169     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3170     Results.push_back(Tmp1);
3171     break;
3172   }
3173   case ISD::EXTRACT_ELEMENT: {
3174     EVT OpTy = Node->getOperand(0).getValueType();
3175     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3176       // 1 -> Hi
3177       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3178                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3179                                          TLI.getShiftAmountTy(
3180                                              Node->getOperand(0).getValueType(),
3181                                              DAG.getDataLayout())));
3182       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3183     } else {
3184       // 0 -> Lo
3185       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3186                          Node->getOperand(0));
3187     }
3188     Results.push_back(Tmp1);
3189     break;
3190   }
3191   case ISD::STACKSAVE:
3192     // Expand to CopyFromReg if the target set
3193     // StackPointerRegisterToSaveRestore.
3194     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3195       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3196                                            Node->getValueType(0)));
3197       Results.push_back(Results[0].getValue(1));
3198     } else {
3199       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3200       Results.push_back(Node->getOperand(0));
3201     }
3202     break;
3203   case ISD::STACKRESTORE:
3204     // Expand to CopyToReg if the target set
3205     // StackPointerRegisterToSaveRestore.
3206     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3207       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3208                                          Node->getOperand(1)));
3209     } else {
3210       Results.push_back(Node->getOperand(0));
3211     }
3212     break;
3213   case ISD::GET_DYNAMIC_AREA_OFFSET:
3214     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3215     Results.push_back(Results[0].getValue(0));
3216     break;
3217   case ISD::FCOPYSIGN:
3218     Results.push_back(ExpandFCOPYSIGN(Node));
3219     break;
3220   case ISD::FNEG:
3221     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3222     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3223     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3224     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3225                        Node->getOperand(0));
3226     Results.push_back(Tmp1);
3227     break;
3228   case ISD::FABS:
3229     Results.push_back(ExpandFABS(Node));
3230     break;
3231   case ISD::SMIN:
3232   case ISD::SMAX:
3233   case ISD::UMIN:
3234   case ISD::UMAX: {
3235     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3236     ISD::CondCode Pred;
3237     switch (Node->getOpcode()) {
3238     default: llvm_unreachable("How did we get here?");
3239     case ISD::SMAX: Pred = ISD::SETGT; break;
3240     case ISD::SMIN: Pred = ISD::SETLT; break;
3241     case ISD::UMAX: Pred = ISD::SETUGT; break;
3242     case ISD::UMIN: Pred = ISD::SETULT; break;
3243     }
3244     Tmp1 = Node->getOperand(0);
3245     Tmp2 = Node->getOperand(1);
3246     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3247     Results.push_back(Tmp1);
3248     break;
3249   }
3250   case ISD::FMINNUM:
3251   case ISD::FMAXNUM: {
3252     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3253       Results.push_back(Expanded);
3254     break;
3255   }
3256   case ISD::FSIN:
3257   case ISD::FCOS: {
3258     EVT VT = Node->getValueType(0);
3259     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3260     // fcos which share the same operand and both are used.
3261     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3262          isSinCosLibcallAvailable(Node, TLI))
3263         && useSinCos(Node)) {
3264       SDVTList VTs = DAG.getVTList(VT, VT);
3265       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3266       if (Node->getOpcode() == ISD::FCOS)
3267         Tmp1 = Tmp1.getValue(1);
3268       Results.push_back(Tmp1);
3269     }
3270     break;
3271   }
3272   case ISD::FMAD:
3273     llvm_unreachable("Illegal fmad should never be formed");
3274 
3275   case ISD::FP16_TO_FP:
3276     if (Node->getValueType(0) != MVT::f32) {
3277       // We can extend to types bigger than f32 in two steps without changing
3278       // the result. Since "f16 -> f32" is much more commonly available, give
3279       // CodeGen the option of emitting that before resorting to a libcall.
3280       SDValue Res =
3281           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3282       Results.push_back(
3283           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3284     }
3285     break;
3286   case ISD::FP_TO_FP16:
3287     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3288     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3289       SDValue Op = Node->getOperand(0);
3290       MVT SVT = Op.getSimpleValueType();
3291       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3292           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3293         // Under fastmath, we can expand this node into a fround followed by
3294         // a float-half conversion.
3295         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3296                                        DAG.getIntPtrConstant(0, dl));
3297         Results.push_back(
3298             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3299       }
3300     }
3301     break;
3302   case ISD::ConstantFP: {
3303     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3304     // Check to see if this FP immediate is already legal.
3305     // If this is a legal constant, turn it into a TargetConstantFP node.
3306     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0)))
3307       Results.push_back(ExpandConstantFP(CFP, true));
3308     break;
3309   }
3310   case ISD::Constant: {
3311     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3312     Results.push_back(ExpandConstant(CP));
3313     break;
3314   }
3315   case ISD::FSUB: {
3316     EVT VT = Node->getValueType(0);
3317     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3318         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3319       const SDNodeFlags Flags = Node->getFlags();
3320       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3321       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3322       Results.push_back(Tmp1);
3323     }
3324     break;
3325   }
3326   case ISD::SUB: {
3327     EVT VT = Node->getValueType(0);
3328     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3329            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3330            "Don't know how to expand this subtraction!");
3331     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3332                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3333                                VT));
3334     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3335     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3336     break;
3337   }
3338   case ISD::UREM:
3339   case ISD::SREM: {
3340     EVT VT = Node->getValueType(0);
3341     bool isSigned = Node->getOpcode() == ISD::SREM;
3342     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
3343     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3344     Tmp2 = Node->getOperand(0);
3345     Tmp3 = Node->getOperand(1);
3346     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3347       SDVTList VTs = DAG.getVTList(VT, VT);
3348       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
3349       Results.push_back(Tmp1);
3350     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
3351       // X % Y -> X-X/Y*Y
3352       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
3353       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
3354       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
3355       Results.push_back(Tmp1);
3356     }
3357     break;
3358   }
3359   case ISD::UDIV:
3360   case ISD::SDIV: {
3361     bool isSigned = Node->getOpcode() == ISD::SDIV;
3362     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3363     EVT VT = Node->getValueType(0);
3364     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3365       SDVTList VTs = DAG.getVTList(VT, VT);
3366       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3367                          Node->getOperand(1));
3368       Results.push_back(Tmp1);
3369     }
3370     break;
3371   }
3372   case ISD::MULHU:
3373   case ISD::MULHS: {
3374     unsigned ExpandOpcode =
3375         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3376     EVT VT = Node->getValueType(0);
3377     SDVTList VTs = DAG.getVTList(VT, VT);
3378 
3379     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3380                        Node->getOperand(1));
3381     Results.push_back(Tmp1.getValue(1));
3382     break;
3383   }
3384   case ISD::UMUL_LOHI:
3385   case ISD::SMUL_LOHI: {
3386     SDValue LHS = Node->getOperand(0);
3387     SDValue RHS = Node->getOperand(1);
3388     MVT VT = LHS.getSimpleValueType();
3389     unsigned MULHOpcode =
3390         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3391 
3392     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3393       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3394       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3395       break;
3396     }
3397 
3398     SmallVector<SDValue, 4> Halves;
3399     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3400     assert(TLI.isTypeLegal(HalfType));
3401     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, Node, LHS, RHS, Halves,
3402                            HalfType, DAG,
3403                            TargetLowering::MulExpansionKind::Always)) {
3404       for (unsigned i = 0; i < 2; ++i) {
3405         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3406         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3407         SDValue Shift = DAG.getConstant(
3408             HalfType.getScalarSizeInBits(), dl,
3409             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3410         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3411         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3412       }
3413       break;
3414     }
3415     break;
3416   }
3417   case ISD::MUL: {
3418     EVT VT = Node->getValueType(0);
3419     SDVTList VTs = DAG.getVTList(VT, VT);
3420     // See if multiply or divide can be lowered using two-result operations.
3421     // We just need the low half of the multiply; try both the signed
3422     // and unsigned forms. If the target supports both SMUL_LOHI and
3423     // UMUL_LOHI, form a preference by checking which forms of plain
3424     // MULH it supports.
3425     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3426     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3427     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3428     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3429     unsigned OpToUse = 0;
3430     if (HasSMUL_LOHI && !HasMULHS) {
3431       OpToUse = ISD::SMUL_LOHI;
3432     } else if (HasUMUL_LOHI && !HasMULHU) {
3433       OpToUse = ISD::UMUL_LOHI;
3434     } else if (HasSMUL_LOHI) {
3435       OpToUse = ISD::SMUL_LOHI;
3436     } else if (HasUMUL_LOHI) {
3437       OpToUse = ISD::UMUL_LOHI;
3438     }
3439     if (OpToUse) {
3440       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3441                                     Node->getOperand(1)));
3442       break;
3443     }
3444 
3445     SDValue Lo, Hi;
3446     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3447     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3448         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3449         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3450         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3451         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3452                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3453       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3454       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3455       SDValue Shift =
3456           DAG.getConstant(HalfType.getSizeInBits(), dl,
3457                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3458       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3459       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3460     }
3461     break;
3462   }
3463   case ISD::SADDSAT: {
3464     Results.push_back(TLI.getExpandedSignedSaturationAddition(Node, DAG));
3465     break;
3466   }
3467   case ISD::SADDO:
3468   case ISD::SSUBO: {
3469     SDValue LHS = Node->getOperand(0);
3470     SDValue RHS = Node->getOperand(1);
3471     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::SADDO ?
3472                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
3473                               LHS, RHS);
3474     Results.push_back(Sum);
3475     EVT ResultType = Node->getValueType(1);
3476     EVT OType = getSetCCResultType(Node->getValueType(0));
3477 
3478     SDValue Zero = DAG.getConstant(0, dl, LHS.getValueType());
3479 
3480     //   LHSSign -> LHS >= 0
3481     //   RHSSign -> RHS >= 0
3482     //   SumSign -> Sum >= 0
3483     //
3484     //   Add:
3485     //   Overflow -> (LHSSign == RHSSign) && (LHSSign != SumSign)
3486     //   Sub:
3487     //   Overflow -> (LHSSign != RHSSign) && (LHSSign != SumSign)
3488     SDValue LHSSign = DAG.getSetCC(dl, OType, LHS, Zero, ISD::SETGE);
3489     SDValue RHSSign = DAG.getSetCC(dl, OType, RHS, Zero, ISD::SETGE);
3490     SDValue SignsMatch = DAG.getSetCC(dl, OType, LHSSign, RHSSign,
3491                                       Node->getOpcode() == ISD::SADDO ?
3492                                       ISD::SETEQ : ISD::SETNE);
3493 
3494     SDValue SumSign = DAG.getSetCC(dl, OType, Sum, Zero, ISD::SETGE);
3495     SDValue SumSignNE = DAG.getSetCC(dl, OType, LHSSign, SumSign, ISD::SETNE);
3496 
3497     SDValue Cmp = DAG.getNode(ISD::AND, dl, OType, SignsMatch, SumSignNE);
3498     Results.push_back(DAG.getBoolExtOrTrunc(Cmp, dl, ResultType, ResultType));
3499     break;
3500   }
3501   case ISD::UADDO:
3502   case ISD::USUBO: {
3503     SDValue LHS = Node->getOperand(0);
3504     SDValue RHS = Node->getOperand(1);
3505     bool IsAdd = Node->getOpcode() == ISD::UADDO;
3506     // If ADD/SUBCARRY is legal, use that instead.
3507     unsigned OpcCarry = IsAdd ? ISD::ADDCARRY : ISD::SUBCARRY;
3508     if (TLI.isOperationLegalOrCustom(OpcCarry, Node->getValueType(0))) {
3509       SDValue CarryIn = DAG.getConstant(0, dl, Node->getValueType(1));
3510       SDValue NodeCarry = DAG.getNode(OpcCarry, dl, Node->getVTList(),
3511                                       { LHS, RHS, CarryIn });
3512       Results.push_back(SDValue(NodeCarry.getNode(), 0));
3513       Results.push_back(SDValue(NodeCarry.getNode(), 1));
3514       break;
3515     }
3516 
3517     SDValue Sum = DAG.getNode(IsAdd ? ISD::ADD : ISD::SUB, dl,
3518                               LHS.getValueType(), LHS, RHS);
3519     Results.push_back(Sum);
3520 
3521     EVT ResultType = Node->getValueType(1);
3522     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3523     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3524     SDValue SetCC = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3525 
3526     Results.push_back(DAG.getBoolExtOrTrunc(SetCC, dl, ResultType, ResultType));
3527     break;
3528   }
3529   case ISD::UMULO:
3530   case ISD::SMULO: {
3531     EVT VT = Node->getValueType(0);
3532     EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
3533     SDValue LHS = Node->getOperand(0);
3534     SDValue RHS = Node->getOperand(1);
3535     SDValue BottomHalf;
3536     SDValue TopHalf;
3537     static const unsigned Ops[2][3] =
3538         { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
3539           { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
3540     bool isSigned = Node->getOpcode() == ISD::SMULO;
3541     if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
3542       BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
3543       TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
3544     } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
3545       BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
3546                                RHS);
3547       TopHalf = BottomHalf.getValue(1);
3548     } else if (TLI.isTypeLegal(WideVT)) {
3549       LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
3550       RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
3551       Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
3552       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3553                                DAG.getIntPtrConstant(0, dl));
3554       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3555                             DAG.getIntPtrConstant(1, dl));
3556     } else {
3557       // We can fall back to a libcall with an illegal type for the MUL if we
3558       // have a libcall big enough.
3559       // Also, we can fall back to a division in some cases, but that's a big
3560       // performance hit in the general case.
3561       RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
3562       if (WideVT == MVT::i16)
3563         LC = RTLIB::MUL_I16;
3564       else if (WideVT == MVT::i32)
3565         LC = RTLIB::MUL_I32;
3566       else if (WideVT == MVT::i64)
3567         LC = RTLIB::MUL_I64;
3568       else if (WideVT == MVT::i128)
3569         LC = RTLIB::MUL_I128;
3570       assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
3571 
3572       SDValue HiLHS;
3573       SDValue HiRHS;
3574       if (isSigned) {
3575         // The high part is obtained by SRA'ing all but one of the bits of low
3576         // part.
3577         unsigned LoSize = VT.getSizeInBits();
3578         HiLHS =
3579             DAG.getNode(ISD::SRA, dl, VT, LHS,
3580                         DAG.getConstant(LoSize - 1, dl,
3581                                         TLI.getPointerTy(DAG.getDataLayout())));
3582         HiRHS =
3583             DAG.getNode(ISD::SRA, dl, VT, RHS,
3584                         DAG.getConstant(LoSize - 1, dl,
3585                                         TLI.getPointerTy(DAG.getDataLayout())));
3586       } else {
3587           HiLHS = DAG.getConstant(0, dl, VT);
3588           HiRHS = DAG.getConstant(0, dl, VT);
3589       }
3590 
3591       // Here we're passing the 2 arguments explicitly as 4 arguments that are
3592       // pre-lowered to the correct types. This all depends upon WideVT not
3593       // being a legal type for the architecture and thus has to be split to
3594       // two arguments.
3595       SDValue Ret;
3596       if(DAG.getDataLayout().isLittleEndian()) {
3597         // Halves of WideVT are packed into registers in different order
3598         // depending on platform endianness. This is usually handled by
3599         // the C calling convention, but we can't defer to it in
3600         // the legalizer.
3601         SDValue Args[] = { LHS, HiLHS, RHS, HiRHS };
3602         Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3603       } else {
3604         SDValue Args[] = { HiLHS, LHS, HiRHS, RHS };
3605         Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3606       }
3607       assert(Ret.getOpcode() == ISD::MERGE_VALUES &&
3608              "Ret value is a collection of constituent nodes holding result.");
3609       BottomHalf = Ret.getOperand(0);
3610       TopHalf = Ret.getOperand(1);
3611     }
3612 
3613     if (isSigned) {
3614       Tmp1 = DAG.getConstant(
3615           VT.getSizeInBits() - 1, dl,
3616           TLI.getShiftAmountTy(BottomHalf.getValueType(), DAG.getDataLayout()));
3617       Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
3618       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf, Tmp1,
3619                              ISD::SETNE);
3620     } else {
3621       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf,
3622                              DAG.getConstant(0, dl, VT), ISD::SETNE);
3623     }
3624 
3625     // Truncate the result if SetCC returns a larger type than needed.
3626     EVT RType = Node->getValueType(1);
3627     if (RType.getSizeInBits() < TopHalf.getValueSizeInBits())
3628       TopHalf = DAG.getNode(ISD::TRUNCATE, dl, RType, TopHalf);
3629 
3630     assert(RType.getSizeInBits() == TopHalf.getValueSizeInBits() &&
3631            "Unexpected result type for S/UMULO legalization");
3632 
3633     Results.push_back(BottomHalf);
3634     Results.push_back(TopHalf);
3635     break;
3636   }
3637   case ISD::BUILD_PAIR: {
3638     EVT PairTy = Node->getValueType(0);
3639     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3640     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3641     Tmp2 = DAG.getNode(
3642         ISD::SHL, dl, PairTy, Tmp2,
3643         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3644                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3645     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3646     break;
3647   }
3648   case ISD::SELECT:
3649     Tmp1 = Node->getOperand(0);
3650     Tmp2 = Node->getOperand(1);
3651     Tmp3 = Node->getOperand(2);
3652     if (Tmp1.getOpcode() == ISD::SETCC) {
3653       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3654                              Tmp2, Tmp3,
3655                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3656     } else {
3657       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3658                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3659                              Tmp2, Tmp3, ISD::SETNE);
3660     }
3661     Results.push_back(Tmp1);
3662     break;
3663   case ISD::BR_JT: {
3664     SDValue Chain = Node->getOperand(0);
3665     SDValue Table = Node->getOperand(1);
3666     SDValue Index = Node->getOperand(2);
3667 
3668     const DataLayout &TD = DAG.getDataLayout();
3669     EVT PTy = TLI.getPointerTy(TD);
3670 
3671     unsigned EntrySize =
3672       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3673 
3674     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3675     // This transformation needs to be done here since otherwise the MIPS
3676     // backend will end up emitting a three instruction multiply sequence
3677     // instead of a single shift and MSP430 will call a runtime function.
3678     if (llvm::isPowerOf2_32(EntrySize))
3679       Index = DAG.getNode(
3680           ISD::SHL, dl, Index.getValueType(), Index,
3681           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3682     else
3683       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3684                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3685     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3686                                Index, Table);
3687 
3688     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3689     SDValue LD = DAG.getExtLoad(
3690         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3691         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3692     Addr = LD;
3693     if (TLI.isJumpTableRelative()) {
3694       // For PIC, the sequence is:
3695       // BRIND(load(Jumptable + index) + RelocBase)
3696       // RelocBase can be JumpTable, GOT or some sort of global base.
3697       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3698                           TLI.getPICJumpTableRelocBase(Table, DAG));
3699     }
3700 
3701     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3702     Results.push_back(Tmp1);
3703     break;
3704   }
3705   case ISD::BRCOND:
3706     // Expand brcond's setcc into its constituent parts and create a BR_CC
3707     // Node.
3708     Tmp1 = Node->getOperand(0);
3709     Tmp2 = Node->getOperand(1);
3710     if (Tmp2.getOpcode() == ISD::SETCC) {
3711       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3712                          Tmp1, Tmp2.getOperand(2),
3713                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3714                          Node->getOperand(2));
3715     } else {
3716       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3717       if (Tmp2.isUndef() ||
3718           (Tmp2.getOpcode() == ISD::AND &&
3719            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3720            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3721         Tmp3 = Tmp2;
3722       else
3723         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3724                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3725       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3726                          DAG.getCondCode(ISD::SETNE), Tmp3,
3727                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3728                          Node->getOperand(2));
3729     }
3730     Results.push_back(Tmp1);
3731     break;
3732   case ISD::SETCC: {
3733     Tmp1 = Node->getOperand(0);
3734     Tmp2 = Node->getOperand(1);
3735     Tmp3 = Node->getOperand(2);
3736     bool Legalized = LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2,
3737                                            Tmp3, NeedInvert, dl);
3738 
3739     if (Legalized) {
3740       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3741       // condition code, create a new SETCC node.
3742       if (Tmp3.getNode())
3743         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3744                            Tmp1, Tmp2, Tmp3);
3745 
3746       // If we expanded the SETCC by inverting the condition code, then wrap
3747       // the existing SETCC in a NOT to restore the intended condition.
3748       if (NeedInvert)
3749         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3750 
3751       Results.push_back(Tmp1);
3752       break;
3753     }
3754 
3755     // Otherwise, SETCC for the given comparison type must be completely
3756     // illegal; expand it into a SELECT_CC.
3757     EVT VT = Node->getValueType(0);
3758     int TrueValue;
3759     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3760     case TargetLowering::ZeroOrOneBooleanContent:
3761     case TargetLowering::UndefinedBooleanContent:
3762       TrueValue = 1;
3763       break;
3764     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3765       TrueValue = -1;
3766       break;
3767     }
3768     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3769                        DAG.getConstant(TrueValue, dl, VT),
3770                        DAG.getConstant(0, dl, VT),
3771                        Tmp3);
3772     Results.push_back(Tmp1);
3773     break;
3774   }
3775   case ISD::SELECT_CC: {
3776     Tmp1 = Node->getOperand(0);   // LHS
3777     Tmp2 = Node->getOperand(1);   // RHS
3778     Tmp3 = Node->getOperand(2);   // True
3779     Tmp4 = Node->getOperand(3);   // False
3780     EVT VT = Node->getValueType(0);
3781     SDValue CC = Node->getOperand(4);
3782     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3783 
3784     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3785       // If the condition code is legal, then we need to expand this
3786       // node using SETCC and SELECT.
3787       EVT CmpVT = Tmp1.getValueType();
3788       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3789              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3790              "expanded.");
3791       EVT CCVT =
3792           TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), CmpVT);
3793       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC);
3794       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3795       break;
3796     }
3797 
3798     // SELECT_CC is legal, so the condition code must not be.
3799     bool Legalized = false;
3800     // Try to legalize by inverting the condition.  This is for targets that
3801     // might support an ordered version of a condition, but not the unordered
3802     // version (or vice versa).
3803     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp,
3804                                                Tmp1.getValueType().isInteger());
3805     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3806       // Use the new condition code and swap true and false
3807       Legalized = true;
3808       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3809     } else {
3810       // If The inverse is not legal, then try to swap the arguments using
3811       // the inverse condition code.
3812       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3813       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3814         // The swapped inverse condition is legal, so swap true and false,
3815         // lhs and rhs.
3816         Legalized = true;
3817         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3818       }
3819     }
3820 
3821     if (!Legalized) {
3822       Legalized = LegalizeSetCCCondCode(
3823           getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC, NeedInvert,
3824           dl);
3825 
3826       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3827 
3828       // If we expanded the SETCC by inverting the condition code, then swap
3829       // the True/False operands to match.
3830       if (NeedInvert)
3831         std::swap(Tmp3, Tmp4);
3832 
3833       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3834       // condition code, create a new SELECT_CC node.
3835       if (CC.getNode()) {
3836         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3837                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3838       } else {
3839         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3840         CC = DAG.getCondCode(ISD::SETNE);
3841         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3842                            Tmp2, Tmp3, Tmp4, CC);
3843       }
3844     }
3845     Results.push_back(Tmp1);
3846     break;
3847   }
3848   case ISD::BR_CC: {
3849     Tmp1 = Node->getOperand(0);              // Chain
3850     Tmp2 = Node->getOperand(2);              // LHS
3851     Tmp3 = Node->getOperand(3);              // RHS
3852     Tmp4 = Node->getOperand(1);              // CC
3853 
3854     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
3855         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, NeedInvert, dl);
3856     (void)Legalized;
3857     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3858 
3859     // If we expanded the SETCC by inverting the condition code, then wrap
3860     // the existing SETCC in a NOT to restore the intended condition.
3861     if (NeedInvert)
3862       Tmp4 = DAG.getNOT(dl, Tmp4, Tmp4->getValueType(0));
3863 
3864     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3865     // node.
3866     if (Tmp4.getNode()) {
3867       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3868                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3869     } else {
3870       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3871       Tmp4 = DAG.getCondCode(ISD::SETNE);
3872       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3873                          Tmp2, Tmp3, Node->getOperand(4));
3874     }
3875     Results.push_back(Tmp1);
3876     break;
3877   }
3878   case ISD::BUILD_VECTOR:
3879     Results.push_back(ExpandBUILD_VECTOR(Node));
3880     break;
3881   case ISD::SRA:
3882   case ISD::SRL:
3883   case ISD::SHL: {
3884     // Scalarize vector SRA/SRL/SHL.
3885     EVT VT = Node->getValueType(0);
3886     assert(VT.isVector() && "Unable to legalize non-vector shift");
3887     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3888     unsigned NumElem = VT.getVectorNumElements();
3889 
3890     SmallVector<SDValue, 8> Scalars;
3891     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3892       SDValue Ex = DAG.getNode(
3893           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(0),
3894           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3895       SDValue Sh = DAG.getNode(
3896           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(1),
3897           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3898       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3899                                     VT.getScalarType(), Ex, Sh));
3900     }
3901 
3902     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3903     ReplaceNode(SDValue(Node, 0), Result);
3904     break;
3905   }
3906   case ISD::ROTL:
3907   case ISD::ROTR: {
3908     bool IsLeft = Node->getOpcode() == ISD::ROTL;
3909     SDValue Op0 = Node->getOperand(0), Op1 = Node->getOperand(1);
3910     EVT ResVT = Node->getValueType(0);
3911     EVT OpVT = Op0.getValueType();
3912     assert(OpVT == ResVT &&
3913            "The result and the operand types of rotate should match");
3914     EVT ShVT = Op1.getValueType();
3915     SDValue Width = DAG.getConstant(OpVT.getScalarSizeInBits(), dl, ShVT);
3916 
3917     // If a rotate in the other direction is legal, use it.
3918     unsigned RevRot = IsLeft ? ISD::ROTR : ISD::ROTL;
3919     if (TLI.isOperationLegal(RevRot, ResVT)) {
3920       SDValue Sub = DAG.getNode(ISD::SUB, dl, ShVT, Width, Op1);
3921       Results.push_back(DAG.getNode(RevRot, dl, ResVT, Op0, Sub));
3922       break;
3923     }
3924 
3925     // Otherwise,
3926     //   (rotl x, c) -> (or (shl x, (and c, w-1)), (srl x, (and w-c, w-1)))
3927     //   (rotr x, c) -> (or (srl x, (and c, w-1)), (shl x, (and w-c, w-1)))
3928     //
3929     assert(isPowerOf2_32(OpVT.getScalarSizeInBits()) &&
3930            "Expecting the type bitwidth to be a power of 2");
3931     unsigned ShOpc = IsLeft ? ISD::SHL : ISD::SRL;
3932     unsigned HsOpc = IsLeft ? ISD::SRL : ISD::SHL;
3933     SDValue Width1 = DAG.getNode(ISD::SUB, dl, ShVT,
3934                                  Width, DAG.getConstant(1, dl, ShVT));
3935     SDValue NegOp1 = DAG.getNode(ISD::SUB, dl, ShVT, Width, Op1);
3936     SDValue And0 = DAG.getNode(ISD::AND, dl, ShVT, Op1, Width1);
3937     SDValue And1 = DAG.getNode(ISD::AND, dl, ShVT, NegOp1, Width1);
3938 
3939     SDValue Or = DAG.getNode(ISD::OR, dl, ResVT,
3940                              DAG.getNode(ShOpc, dl, ResVT, Op0, And0),
3941                              DAG.getNode(HsOpc, dl, ResVT, Op0, And1));
3942     Results.push_back(Or);
3943     break;
3944   }
3945 
3946   case ISD::GLOBAL_OFFSET_TABLE:
3947   case ISD::GlobalAddress:
3948   case ISD::GlobalTLSAddress:
3949   case ISD::ExternalSymbol:
3950   case ISD::ConstantPool:
3951   case ISD::JumpTable:
3952   case ISD::INTRINSIC_W_CHAIN:
3953   case ISD::INTRINSIC_WO_CHAIN:
3954   case ISD::INTRINSIC_VOID:
3955     // FIXME: Custom lowering for these operations shouldn't return null!
3956     break;
3957   }
3958 
3959   // Replace the original node with the legalized result.
3960   if (Results.empty()) {
3961     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3962     return false;
3963   }
3964 
3965   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3966   ReplaceNode(Node, Results.data());
3967   return true;
3968 }
3969 
3970 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3971   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3972   SmallVector<SDValue, 8> Results;
3973   SDLoc dl(Node);
3974   // FIXME: Check flags on the node to see if we can use a finite call.
3975   bool CanUseFiniteLibCall = TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath;
3976   unsigned Opc = Node->getOpcode();
3977   switch (Opc) {
3978   case ISD::ATOMIC_FENCE: {
3979     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3980     // FIXME: handle "fence singlethread" more efficiently.
3981     TargetLowering::ArgListTy Args;
3982 
3983     TargetLowering::CallLoweringInfo CLI(DAG);
3984     CLI.setDebugLoc(dl)
3985         .setChain(Node->getOperand(0))
3986         .setLibCallee(
3987             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3988             DAG.getExternalSymbol("__sync_synchronize",
3989                                   TLI.getPointerTy(DAG.getDataLayout())),
3990             std::move(Args));
3991 
3992     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3993 
3994     Results.push_back(CallResult.second);
3995     break;
3996   }
3997   // By default, atomic intrinsics are marked Legal and lowered. Targets
3998   // which don't support them directly, however, may want libcalls, in which
3999   // case they mark them Expand, and we get here.
4000   case ISD::ATOMIC_SWAP:
4001   case ISD::ATOMIC_LOAD_ADD:
4002   case ISD::ATOMIC_LOAD_SUB:
4003   case ISD::ATOMIC_LOAD_AND:
4004   case ISD::ATOMIC_LOAD_CLR:
4005   case ISD::ATOMIC_LOAD_OR:
4006   case ISD::ATOMIC_LOAD_XOR:
4007   case ISD::ATOMIC_LOAD_NAND:
4008   case ISD::ATOMIC_LOAD_MIN:
4009   case ISD::ATOMIC_LOAD_MAX:
4010   case ISD::ATOMIC_LOAD_UMIN:
4011   case ISD::ATOMIC_LOAD_UMAX:
4012   case ISD::ATOMIC_CMP_SWAP: {
4013     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
4014     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
4015     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
4016 
4017     std::pair<SDValue, SDValue> Tmp = ExpandChainLibCall(LC, Node, false);
4018     Results.push_back(Tmp.first);
4019     Results.push_back(Tmp.second);
4020     break;
4021   }
4022   case ISD::TRAP: {
4023     // If this operation is not supported, lower it to 'abort()' call
4024     TargetLowering::ArgListTy Args;
4025     TargetLowering::CallLoweringInfo CLI(DAG);
4026     CLI.setDebugLoc(dl)
4027         .setChain(Node->getOperand(0))
4028         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
4029                       DAG.getExternalSymbol(
4030                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
4031                       std::move(Args));
4032     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
4033 
4034     Results.push_back(CallResult.second);
4035     break;
4036   }
4037   case ISD::FMINNUM:
4038     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
4039                                       RTLIB::FMIN_F80, RTLIB::FMIN_F128,
4040                                       RTLIB::FMIN_PPCF128));
4041     break;
4042   case ISD::FMAXNUM:
4043     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
4044                                       RTLIB::FMAX_F80, RTLIB::FMAX_F128,
4045                                       RTLIB::FMAX_PPCF128));
4046     break;
4047   case ISD::FSQRT:
4048   case ISD::STRICT_FSQRT:
4049     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
4050                                       RTLIB::SQRT_F80, RTLIB::SQRT_F128,
4051                                       RTLIB::SQRT_PPCF128));
4052     break;
4053   case ISD::FCBRT:
4054     Results.push_back(ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
4055                                       RTLIB::CBRT_F80, RTLIB::CBRT_F128,
4056                                       RTLIB::CBRT_PPCF128));
4057     break;
4058   case ISD::FSIN:
4059   case ISD::STRICT_FSIN:
4060     Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
4061                                       RTLIB::SIN_F80, RTLIB::SIN_F128,
4062                                       RTLIB::SIN_PPCF128));
4063     break;
4064   case ISD::FCOS:
4065   case ISD::STRICT_FCOS:
4066     Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
4067                                       RTLIB::COS_F80, RTLIB::COS_F128,
4068                                       RTLIB::COS_PPCF128));
4069     break;
4070   case ISD::FSINCOS:
4071     // Expand into sincos libcall.
4072     ExpandSinCosLibCall(Node, Results);
4073     break;
4074   case ISD::FLOG:
4075   case ISD::STRICT_FLOG:
4076     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log_finite))
4077       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_FINITE_F32,
4078                                         RTLIB::LOG_FINITE_F64,
4079                                         RTLIB::LOG_FINITE_F80,
4080                                         RTLIB::LOG_FINITE_F128,
4081                                         RTLIB::LOG_FINITE_PPCF128));
4082     else
4083       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
4084                                         RTLIB::LOG_F80, RTLIB::LOG_F128,
4085                                         RTLIB::LOG_PPCF128));
4086     break;
4087   case ISD::FLOG2:
4088   case ISD::STRICT_FLOG2:
4089     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log2_finite))
4090       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_FINITE_F32,
4091                                         RTLIB::LOG2_FINITE_F64,
4092                                         RTLIB::LOG2_FINITE_F80,
4093                                         RTLIB::LOG2_FINITE_F128,
4094                                         RTLIB::LOG2_FINITE_PPCF128));
4095     else
4096       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
4097                                         RTLIB::LOG2_F80, RTLIB::LOG2_F128,
4098                                         RTLIB::LOG2_PPCF128));
4099     break;
4100   case ISD::FLOG10:
4101   case ISD::STRICT_FLOG10:
4102     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log10_finite))
4103       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_FINITE_F32,
4104                                         RTLIB::LOG10_FINITE_F64,
4105                                         RTLIB::LOG10_FINITE_F80,
4106                                         RTLIB::LOG10_FINITE_F128,
4107                                         RTLIB::LOG10_FINITE_PPCF128));
4108     else
4109       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
4110                                         RTLIB::LOG10_F80, RTLIB::LOG10_F128,
4111                                         RTLIB::LOG10_PPCF128));
4112     break;
4113   case ISD::FEXP:
4114   case ISD::STRICT_FEXP:
4115     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp_finite))
4116       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_FINITE_F32,
4117                                         RTLIB::EXP_FINITE_F64,
4118                                         RTLIB::EXP_FINITE_F80,
4119                                         RTLIB::EXP_FINITE_F128,
4120                                         RTLIB::EXP_FINITE_PPCF128));
4121     else
4122       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
4123                                         RTLIB::EXP_F80, RTLIB::EXP_F128,
4124                                         RTLIB::EXP_PPCF128));
4125     break;
4126   case ISD::FEXP2:
4127   case ISD::STRICT_FEXP2:
4128     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp2_finite))
4129       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_FINITE_F32,
4130                                         RTLIB::EXP2_FINITE_F64,
4131                                         RTLIB::EXP2_FINITE_F80,
4132                                         RTLIB::EXP2_FINITE_F128,
4133                                         RTLIB::EXP2_FINITE_PPCF128));
4134     else
4135       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
4136                                         RTLIB::EXP2_F80, RTLIB::EXP2_F128,
4137                                         RTLIB::EXP2_PPCF128));
4138     break;
4139   case ISD::FTRUNC:
4140     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4141                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4142                                       RTLIB::TRUNC_PPCF128));
4143     break;
4144   case ISD::FFLOOR:
4145     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4146                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4147                                       RTLIB::FLOOR_PPCF128));
4148     break;
4149   case ISD::FCEIL:
4150     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4151                                       RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4152                                       RTLIB::CEIL_PPCF128));
4153     break;
4154   case ISD::FRINT:
4155   case ISD::STRICT_FRINT:
4156     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4157                                       RTLIB::RINT_F80, RTLIB::RINT_F128,
4158                                       RTLIB::RINT_PPCF128));
4159     break;
4160   case ISD::FNEARBYINT:
4161   case ISD::STRICT_FNEARBYINT:
4162     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4163                                       RTLIB::NEARBYINT_F64,
4164                                       RTLIB::NEARBYINT_F80,
4165                                       RTLIB::NEARBYINT_F128,
4166                                       RTLIB::NEARBYINT_PPCF128));
4167     break;
4168   case ISD::FROUND:
4169     Results.push_back(ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4170                                       RTLIB::ROUND_F64,
4171                                       RTLIB::ROUND_F80,
4172                                       RTLIB::ROUND_F128,
4173                                       RTLIB::ROUND_PPCF128));
4174     break;
4175   case ISD::FPOWI:
4176   case ISD::STRICT_FPOWI:
4177     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
4178                                       RTLIB::POWI_F80, RTLIB::POWI_F128,
4179                                       RTLIB::POWI_PPCF128));
4180     break;
4181   case ISD::FPOW:
4182   case ISD::STRICT_FPOW:
4183     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_pow_finite))
4184       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_FINITE_F32,
4185                                         RTLIB::POW_FINITE_F64,
4186                                         RTLIB::POW_FINITE_F80,
4187                                         RTLIB::POW_FINITE_F128,
4188                                         RTLIB::POW_FINITE_PPCF128));
4189     else
4190       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
4191                                         RTLIB::POW_F80, RTLIB::POW_F128,
4192                                         RTLIB::POW_PPCF128));
4193     break;
4194   case ISD::FDIV:
4195     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4196                                       RTLIB::DIV_F80, RTLIB::DIV_F128,
4197                                       RTLIB::DIV_PPCF128));
4198     break;
4199   case ISD::FREM:
4200   case ISD::STRICT_FREM:
4201     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4202                                       RTLIB::REM_F80, RTLIB::REM_F128,
4203                                       RTLIB::REM_PPCF128));
4204     break;
4205   case ISD::FMA:
4206   case ISD::STRICT_FMA:
4207     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4208                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
4209                                       RTLIB::FMA_PPCF128));
4210     break;
4211   case ISD::FADD:
4212     Results.push_back(ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4213                                       RTLIB::ADD_F80, RTLIB::ADD_F128,
4214                                       RTLIB::ADD_PPCF128));
4215     break;
4216   case ISD::FMUL:
4217     Results.push_back(ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4218                                       RTLIB::MUL_F80, RTLIB::MUL_F128,
4219                                       RTLIB::MUL_PPCF128));
4220     break;
4221   case ISD::FP16_TO_FP:
4222     if (Node->getValueType(0) == MVT::f32) {
4223       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4224     }
4225     break;
4226   case ISD::FP_TO_FP16: {
4227     RTLIB::Libcall LC =
4228         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4229     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4230     Results.push_back(ExpandLibCall(LC, Node, false));
4231     break;
4232   }
4233   case ISD::FSUB:
4234     Results.push_back(ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4235                                       RTLIB::SUB_F80, RTLIB::SUB_F128,
4236                                       RTLIB::SUB_PPCF128));
4237     break;
4238   case ISD::SREM:
4239     Results.push_back(ExpandIntLibCall(Node, true,
4240                                        RTLIB::SREM_I8,
4241                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4242                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4243     break;
4244   case ISD::UREM:
4245     Results.push_back(ExpandIntLibCall(Node, false,
4246                                        RTLIB::UREM_I8,
4247                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4248                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4249     break;
4250   case ISD::SDIV:
4251     Results.push_back(ExpandIntLibCall(Node, true,
4252                                        RTLIB::SDIV_I8,
4253                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4254                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4255     break;
4256   case ISD::UDIV:
4257     Results.push_back(ExpandIntLibCall(Node, false,
4258                                        RTLIB::UDIV_I8,
4259                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4260                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4261     break;
4262   case ISD::SDIVREM:
4263   case ISD::UDIVREM:
4264     // Expand into divrem libcall
4265     ExpandDivRemLibCall(Node, Results);
4266     break;
4267   case ISD::MUL:
4268     Results.push_back(ExpandIntLibCall(Node, false,
4269                                        RTLIB::MUL_I8,
4270                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4271                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4272     break;
4273   case ISD::CTLZ_ZERO_UNDEF:
4274     switch (Node->getSimpleValueType(0).SimpleTy) {
4275     default:
4276       llvm_unreachable("LibCall explicitly requested, but not available");
4277     case MVT::i32:
4278       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4279       break;
4280     case MVT::i64:
4281       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4282       break;
4283     case MVT::i128:
4284       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4285       break;
4286     }
4287     break;
4288   }
4289 
4290   // Replace the original node with the legalized result.
4291   if (!Results.empty()) {
4292     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4293     ReplaceNode(Node, Results.data());
4294   } else
4295     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4296 }
4297 
4298 // Determine the vector type to use in place of an original scalar element when
4299 // promoting equally sized vectors.
4300 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4301                                         MVT EltVT, MVT NewEltVT) {
4302   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4303   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4304   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4305   return MidVT;
4306 }
4307 
4308 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4309   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4310   SmallVector<SDValue, 8> Results;
4311   MVT OVT = Node->getSimpleValueType(0);
4312   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4313       Node->getOpcode() == ISD::SINT_TO_FP ||
4314       Node->getOpcode() == ISD::SETCC ||
4315       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4316       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4317     OVT = Node->getOperand(0).getSimpleValueType();
4318   }
4319   if (Node->getOpcode() == ISD::BR_CC)
4320     OVT = Node->getOperand(2).getSimpleValueType();
4321   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4322   SDLoc dl(Node);
4323   SDValue Tmp1, Tmp2, Tmp3;
4324   switch (Node->getOpcode()) {
4325   case ISD::CTTZ:
4326   case ISD::CTTZ_ZERO_UNDEF:
4327   case ISD::CTLZ:
4328   case ISD::CTLZ_ZERO_UNDEF:
4329   case ISD::CTPOP:
4330     // Zero extend the argument.
4331     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4332     if (Node->getOpcode() == ISD::CTTZ) {
4333       // The count is the same in the promoted type except if the original
4334       // value was zero.  This can be handled by setting the bit just off
4335       // the top of the original type.
4336       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4337                                         OVT.getSizeInBits());
4338       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4339                          DAG.getConstant(TopBit, dl, NVT));
4340     }
4341     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4342     // already the correct result.
4343     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4344     if (Node->getOpcode() == ISD::CTLZ ||
4345         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4346       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4347       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4348                           DAG.getConstant(NVT.getSizeInBits() -
4349                                           OVT.getSizeInBits(), dl, NVT));
4350     }
4351     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4352     break;
4353   case ISD::BITREVERSE:
4354   case ISD::BSWAP: {
4355     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4356     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4357     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4358     Tmp1 = DAG.getNode(
4359         ISD::SRL, dl, NVT, Tmp1,
4360         DAG.getConstant(DiffBits, dl,
4361                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4362 
4363     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4364     break;
4365   }
4366   case ISD::FP_TO_UINT:
4367   case ISD::FP_TO_SINT:
4368     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
4369                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
4370     Results.push_back(Tmp1);
4371     break;
4372   case ISD::UINT_TO_FP:
4373   case ISD::SINT_TO_FP:
4374     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
4375                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
4376     Results.push_back(Tmp1);
4377     break;
4378   case ISD::VAARG: {
4379     SDValue Chain = Node->getOperand(0); // Get the chain.
4380     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4381 
4382     unsigned TruncOp;
4383     if (OVT.isVector()) {
4384       TruncOp = ISD::BITCAST;
4385     } else {
4386       assert(OVT.isInteger()
4387         && "VAARG promotion is supported only for vectors or integer types");
4388       TruncOp = ISD::TRUNCATE;
4389     }
4390 
4391     // Perform the larger operation, then convert back
4392     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4393              Node->getConstantOperandVal(3));
4394     Chain = Tmp1.getValue(1);
4395 
4396     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4397 
4398     // Modified the chain result - switch anything that used the old chain to
4399     // use the new one.
4400     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4401     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4402     if (UpdatedNodes) {
4403       UpdatedNodes->insert(Tmp2.getNode());
4404       UpdatedNodes->insert(Chain.getNode());
4405     }
4406     ReplacedNode(Node);
4407     break;
4408   }
4409   case ISD::MUL:
4410   case ISD::SDIV:
4411   case ISD::SREM:
4412   case ISD::UDIV:
4413   case ISD::UREM:
4414   case ISD::AND:
4415   case ISD::OR:
4416   case ISD::XOR: {
4417     unsigned ExtOp, TruncOp;
4418     if (OVT.isVector()) {
4419       ExtOp   = ISD::BITCAST;
4420       TruncOp = ISD::BITCAST;
4421     } else {
4422       assert(OVT.isInteger() && "Cannot promote logic operation");
4423 
4424       switch (Node->getOpcode()) {
4425       default:
4426         ExtOp = ISD::ANY_EXTEND;
4427         break;
4428       case ISD::SDIV:
4429       case ISD::SREM:
4430         ExtOp = ISD::SIGN_EXTEND;
4431         break;
4432       case ISD::UDIV:
4433       case ISD::UREM:
4434         ExtOp = ISD::ZERO_EXTEND;
4435         break;
4436       }
4437       TruncOp = ISD::TRUNCATE;
4438     }
4439     // Promote each of the values to the new type.
4440     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4441     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4442     // Perform the larger operation, then convert back
4443     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4444     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4445     break;
4446   }
4447   case ISD::UMUL_LOHI:
4448   case ISD::SMUL_LOHI: {
4449     // Promote to a multiply in a wider integer type.
4450     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4451                                                          : ISD::SIGN_EXTEND;
4452     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4453     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4454     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4455 
4456     auto &DL = DAG.getDataLayout();
4457     unsigned OriginalSize = OVT.getScalarSizeInBits();
4458     Tmp2 = DAG.getNode(
4459         ISD::SRL, dl, NVT, Tmp1,
4460         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4461     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4462     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4463     break;
4464   }
4465   case ISD::SELECT: {
4466     unsigned ExtOp, TruncOp;
4467     if (Node->getValueType(0).isVector() ||
4468         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4469       ExtOp   = ISD::BITCAST;
4470       TruncOp = ISD::BITCAST;
4471     } else if (Node->getValueType(0).isInteger()) {
4472       ExtOp   = ISD::ANY_EXTEND;
4473       TruncOp = ISD::TRUNCATE;
4474     } else {
4475       ExtOp   = ISD::FP_EXTEND;
4476       TruncOp = ISD::FP_ROUND;
4477     }
4478     Tmp1 = Node->getOperand(0);
4479     // Promote each of the values to the new type.
4480     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4481     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4482     // Perform the larger operation, then round down.
4483     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4484     if (TruncOp != ISD::FP_ROUND)
4485       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4486     else
4487       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4488                          DAG.getIntPtrConstant(0, dl));
4489     Results.push_back(Tmp1);
4490     break;
4491   }
4492   case ISD::VECTOR_SHUFFLE: {
4493     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4494 
4495     // Cast the two input vectors.
4496     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4497     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4498 
4499     // Convert the shuffle mask to the right # elements.
4500     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4501     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4502     Results.push_back(Tmp1);
4503     break;
4504   }
4505   case ISD::SETCC: {
4506     unsigned ExtOp = ISD::FP_EXTEND;
4507     if (NVT.isInteger()) {
4508       ISD::CondCode CCCode =
4509         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4510       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4511     }
4512     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4513     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4514     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
4515                                   Tmp1, Tmp2, Node->getOperand(2)));
4516     break;
4517   }
4518   case ISD::BR_CC: {
4519     unsigned ExtOp = ISD::FP_EXTEND;
4520     if (NVT.isInteger()) {
4521       ISD::CondCode CCCode =
4522         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4523       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4524     }
4525     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4526     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4527     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4528                                   Node->getOperand(0), Node->getOperand(1),
4529                                   Tmp1, Tmp2, Node->getOperand(4)));
4530     break;
4531   }
4532   case ISD::FADD:
4533   case ISD::FSUB:
4534   case ISD::FMUL:
4535   case ISD::FDIV:
4536   case ISD::FREM:
4537   case ISD::FMINNUM:
4538   case ISD::FMAXNUM:
4539   case ISD::FPOW:
4540     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4541     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4542     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4543                        Node->getFlags());
4544     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4545                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4546     break;
4547   case ISD::FMA:
4548     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4549     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4550     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4551     Results.push_back(
4552         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4553                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4554                     DAG.getIntPtrConstant(0, dl)));
4555     break;
4556   case ISD::FCOPYSIGN:
4557   case ISD::FPOWI: {
4558     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4559     Tmp2 = Node->getOperand(1);
4560     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4561 
4562     // fcopysign doesn't change anything but the sign bit, so
4563     //   (fp_round (fcopysign (fpext a), b))
4564     // is as precise as
4565     //   (fp_round (fpext a))
4566     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4567     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4568     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4569                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4570     break;
4571   }
4572   case ISD::FFLOOR:
4573   case ISD::FCEIL:
4574   case ISD::FRINT:
4575   case ISD::FNEARBYINT:
4576   case ISD::FROUND:
4577   case ISD::FTRUNC:
4578   case ISD::FNEG:
4579   case ISD::FSQRT:
4580   case ISD::FSIN:
4581   case ISD::FCOS:
4582   case ISD::FLOG:
4583   case ISD::FLOG2:
4584   case ISD::FLOG10:
4585   case ISD::FABS:
4586   case ISD::FEXP:
4587   case ISD::FEXP2:
4588     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4589     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4590     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4591                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4592     break;
4593   case ISD::BUILD_VECTOR: {
4594     MVT EltVT = OVT.getVectorElementType();
4595     MVT NewEltVT = NVT.getVectorElementType();
4596 
4597     // Handle bitcasts to a different vector type with the same total bit size
4598     //
4599     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4600     //  =>
4601     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4602 
4603     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4604            "Invalid promote type for build_vector");
4605     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4606 
4607     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4608 
4609     SmallVector<SDValue, 8> NewOps;
4610     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4611       SDValue Op = Node->getOperand(I);
4612       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4613     }
4614 
4615     SDLoc SL(Node);
4616     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4617     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4618     Results.push_back(CvtVec);
4619     break;
4620   }
4621   case ISD::EXTRACT_VECTOR_ELT: {
4622     MVT EltVT = OVT.getVectorElementType();
4623     MVT NewEltVT = NVT.getVectorElementType();
4624 
4625     // Handle bitcasts to a different vector type with the same total bit size.
4626     //
4627     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4628     //  =>
4629     //  v4i32:castx = bitcast x:v2i64
4630     //
4631     // i64 = bitcast
4632     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4633     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4634     //
4635 
4636     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4637            "Invalid promote type for extract_vector_elt");
4638     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4639 
4640     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4641     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4642 
4643     SDValue Idx = Node->getOperand(1);
4644     EVT IdxVT = Idx.getValueType();
4645     SDLoc SL(Node);
4646     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4647     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4648 
4649     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4650 
4651     SmallVector<SDValue, 8> NewOps;
4652     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4653       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4654       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4655 
4656       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4657                                 CastVec, TmpIdx);
4658       NewOps.push_back(Elt);
4659     }
4660 
4661     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4662     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4663     break;
4664   }
4665   case ISD::INSERT_VECTOR_ELT: {
4666     MVT EltVT = OVT.getVectorElementType();
4667     MVT NewEltVT = NVT.getVectorElementType();
4668 
4669     // Handle bitcasts to a different vector type with the same total bit size
4670     //
4671     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4672     //  =>
4673     //  v4i32:castx = bitcast x:v2i64
4674     //  v2i32:casty = bitcast y:i64
4675     //
4676     // v2i64 = bitcast
4677     //   (v4i32 insert_vector_elt
4678     //       (v4i32 insert_vector_elt v4i32:castx,
4679     //                                (extract_vector_elt casty, 0), 2 * z),
4680     //        (extract_vector_elt casty, 1), (2 * z + 1))
4681 
4682     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4683            "Invalid promote type for insert_vector_elt");
4684     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4685 
4686     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4687     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4688 
4689     SDValue Val = Node->getOperand(1);
4690     SDValue Idx = Node->getOperand(2);
4691     EVT IdxVT = Idx.getValueType();
4692     SDLoc SL(Node);
4693 
4694     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4695     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4696 
4697     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4698     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4699 
4700     SDValue NewVec = CastVec;
4701     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4702       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4703       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4704 
4705       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4706                                 CastVal, IdxOffset);
4707 
4708       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4709                            NewVec, Elt, InEltIdx);
4710     }
4711 
4712     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4713     break;
4714   }
4715   case ISD::SCALAR_TO_VECTOR: {
4716     MVT EltVT = OVT.getVectorElementType();
4717     MVT NewEltVT = NVT.getVectorElementType();
4718 
4719     // Handle bitcasts to different vector type with the same total bit size.
4720     //
4721     // e.g. v2i64 = scalar_to_vector x:i64
4722     //   =>
4723     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4724     //
4725 
4726     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4727     SDValue Val = Node->getOperand(0);
4728     SDLoc SL(Node);
4729 
4730     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4731     SDValue Undef = DAG.getUNDEF(MidVT);
4732 
4733     SmallVector<SDValue, 8> NewElts;
4734     NewElts.push_back(CastVal);
4735     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4736       NewElts.push_back(Undef);
4737 
4738     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4739     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4740     Results.push_back(CvtVec);
4741     break;
4742   }
4743   }
4744 
4745   // Replace the original node with the legalized result.
4746   if (!Results.empty()) {
4747     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4748     ReplaceNode(Node, Results.data());
4749   } else
4750     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4751 }
4752 
4753 /// This is the entry point for the file.
4754 void SelectionDAG::Legalize() {
4755   AssignTopologicalOrder();
4756 
4757   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4758   // Use a delete listener to remove nodes which were deleted during
4759   // legalization from LegalizeNodes. This is needed to handle the situation
4760   // where a new node is allocated by the object pool to the same address of a
4761   // previously deleted node.
4762   DAGNodeDeletedListener DeleteListener(
4763       *this,
4764       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4765 
4766   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4767 
4768   // Visit all the nodes. We start in topological order, so that we see
4769   // nodes with their original operands intact. Legalization can produce
4770   // new nodes which may themselves need to be legalized. Iterate until all
4771   // nodes have been legalized.
4772   while (true) {
4773     bool AnyLegalized = false;
4774     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4775       --NI;
4776 
4777       SDNode *N = &*NI;
4778       if (N->use_empty() && N != getRoot().getNode()) {
4779         ++NI;
4780         DeleteNode(N);
4781         continue;
4782       }
4783 
4784       if (LegalizedNodes.insert(N).second) {
4785         AnyLegalized = true;
4786         Legalizer.LegalizeOp(N);
4787 
4788         if (N->use_empty() && N != getRoot().getNode()) {
4789           ++NI;
4790           DeleteNode(N);
4791         }
4792       }
4793     }
4794     if (!AnyLegalized)
4795       break;
4796 
4797   }
4798 
4799   // Remove dead nodes now.
4800   RemoveDeadNodes();
4801 }
4802 
4803 bool SelectionDAG::LegalizeOp(SDNode *N,
4804                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4805   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4806   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4807 
4808   // Directly insert the node in question, and legalize it. This will recurse
4809   // as needed through operands.
4810   LegalizedNodes.insert(N);
4811   Legalizer.LegalizeOp(N);
4812 
4813   return LegalizedNodes.count(N);
4814 }
4815