1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the SelectionDAG::Legalize method.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/APFloat.h"
14 #include "llvm/ADT/APInt.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/SetVector.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/SmallSet.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/CodeGen/ISDOpcodes.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineJumpTableInfo.h"
23 #include "llvm/CodeGen/MachineMemOperand.h"
24 #include "llvm/CodeGen/RuntimeLibcalls.h"
25 #include "llvm/CodeGen/SelectionDAG.h"
26 #include "llvm/CodeGen/SelectionDAGNodes.h"
27 #include "llvm/CodeGen/TargetFrameLowering.h"
28 #include "llvm/CodeGen/TargetLowering.h"
29 #include "llvm/CodeGen/TargetSubtargetInfo.h"
30 #include "llvm/CodeGen/ValueTypes.h"
31 #include "llvm/IR/CallingConv.h"
32 #include "llvm/IR/Constants.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/DerivedTypes.h"
35 #include "llvm/IR/Function.h"
36 #include "llvm/IR/Metadata.h"
37 #include "llvm/IR/Type.h"
38 #include "llvm/Support/Casting.h"
39 #include "llvm/Support/Compiler.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/MachineValueType.h"
43 #include "llvm/Support/MathExtras.h"
44 #include "llvm/Support/raw_ostream.h"
45 #include "llvm/Target/TargetMachine.h"
46 #include "llvm/Target/TargetOptions.h"
47 #include <algorithm>
48 #include <cassert>
49 #include <cstdint>
50 #include <tuple>
51 #include <utility>
52 
53 using namespace llvm;
54 
55 #define DEBUG_TYPE "legalizedag"
56 
57 namespace {
58 
59 /// Keeps track of state when getting the sign of a floating-point value as an
60 /// integer.
61 struct FloatSignAsInt {
62   EVT FloatVT;
63   SDValue Chain;
64   SDValue FloatPtr;
65   SDValue IntPtr;
66   MachinePointerInfo IntPointerInfo;
67   MachinePointerInfo FloatPointerInfo;
68   SDValue IntValue;
69   APInt SignMask;
70   uint8_t SignBit;
71 };
72 
73 //===----------------------------------------------------------------------===//
74 /// This takes an arbitrary SelectionDAG as input and
75 /// hacks on it until the target machine can handle it.  This involves
76 /// eliminating value sizes the machine cannot handle (promoting small sizes to
77 /// large sizes or splitting up large values into small values) as well as
78 /// eliminating operations the machine cannot handle.
79 ///
80 /// This code also does a small amount of optimization and recognition of idioms
81 /// as part of its processing.  For example, if a target does not support a
82 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
83 /// will attempt merge setcc and brc instructions into brcc's.
84 class SelectionDAGLegalize {
85   const TargetMachine &TM;
86   const TargetLowering &TLI;
87   SelectionDAG &DAG;
88 
89   /// The set of nodes which have already been legalized. We hold a
90   /// reference to it in order to update as necessary on node deletion.
91   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
92 
93   /// A set of all the nodes updated during legalization.
94   SmallSetVector<SDNode *, 16> *UpdatedNodes;
95 
96   EVT getSetCCResultType(EVT VT) const {
97     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
98   }
99 
100   // Libcall insertion helpers.
101 
102 public:
103   SelectionDAGLegalize(SelectionDAG &DAG,
104                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
105                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
106       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
107         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
108 
109   /// Legalizes the given operation.
110   void LegalizeOp(SDNode *Node);
111 
112 private:
113   SDValue OptimizeFloatStore(StoreSDNode *ST);
114 
115   void LegalizeLoadOps(SDNode *Node);
116   void LegalizeStoreOps(SDNode *Node);
117 
118   /// Some targets cannot handle a variable
119   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
120   /// is necessary to spill the vector being inserted into to memory, perform
121   /// the insert there, and then read the result back.
122   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
123                                          const SDLoc &dl);
124   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
125                                   const SDLoc &dl);
126 
127   /// Return a vector shuffle operation which
128   /// performs the same shuffe in terms of order or result bytes, but on a type
129   /// whose vector element type is narrower than the original shuffle type.
130   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
131   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
132                                      SDValue N1, SDValue N2,
133                                      ArrayRef<int> Mask) const;
134 
135   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
136                              bool &NeedInvert, const SDLoc &dl);
137 
138   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
139 
140   std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
141                                                  SDNode *Node, bool isSigned);
142   SDValue ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
143                           RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
144                           RTLIB::Libcall Call_F128,
145                           RTLIB::Libcall Call_PPCF128);
146   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
147                            RTLIB::Libcall Call_I8,
148                            RTLIB::Libcall Call_I16,
149                            RTLIB::Libcall Call_I32,
150                            RTLIB::Libcall Call_I64,
151                            RTLIB::Libcall Call_I128);
152   SDValue ExpandArgFPLibCall(SDNode *Node,
153                              RTLIB::Libcall Call_F32, RTLIB::Libcall Call_F64,
154                              RTLIB::Libcall Call_F80, RTLIB::Libcall Call_F128,
155                              RTLIB::Libcall Call_PPCF128);
156   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
157   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
158 
159   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
160                            const SDLoc &dl);
161   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
162                            const SDLoc &dl, SDValue ChainIn);
163   SDValue ExpandBUILD_VECTOR(SDNode *Node);
164   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
165   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
166                                 SmallVectorImpl<SDValue> &Results);
167   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
168                          SDValue Value) const;
169   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
170                           SDValue NewIntValue) const;
171   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
172   SDValue ExpandFABS(SDNode *Node) const;
173   SDValue ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0, EVT DestVT,
174                                const SDLoc &dl);
175   SDValue PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT, bool isSigned,
176                                 const SDLoc &dl);
177   SDValue PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT, bool isSigned,
178                                 const SDLoc &dl);
179 
180   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
181   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
182 
183   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
184   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
185   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
186 
187   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
188   SDValue ExpandConstant(ConstantSDNode *CP);
189 
190   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
191   bool ExpandNode(SDNode *Node);
192   void ConvertNodeToLibcall(SDNode *Node);
193   void PromoteNode(SDNode *Node);
194 
195 public:
196   // Node replacement helpers
197 
198   void ReplacedNode(SDNode *N) {
199     LegalizedNodes.erase(N);
200     if (UpdatedNodes)
201       UpdatedNodes->insert(N);
202   }
203 
204   void ReplaceNode(SDNode *Old, SDNode *New) {
205     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
206                dbgs() << "     with:      "; New->dump(&DAG));
207 
208     assert(Old->getNumValues() == New->getNumValues() &&
209            "Replacing one node with another that produces a different number "
210            "of values!");
211     DAG.ReplaceAllUsesWith(Old, New);
212     if (UpdatedNodes)
213       UpdatedNodes->insert(New);
214     ReplacedNode(Old);
215   }
216 
217   void ReplaceNode(SDValue Old, SDValue New) {
218     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
219                dbgs() << "     with:      "; New->dump(&DAG));
220 
221     DAG.ReplaceAllUsesWith(Old, New);
222     if (UpdatedNodes)
223       UpdatedNodes->insert(New.getNode());
224     ReplacedNode(Old.getNode());
225   }
226 
227   void ReplaceNode(SDNode *Old, const SDValue *New) {
228     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
229 
230     DAG.ReplaceAllUsesWith(Old, New);
231     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
232       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
233                  New[i]->dump(&DAG));
234       if (UpdatedNodes)
235         UpdatedNodes->insert(New[i].getNode());
236     }
237     ReplacedNode(Old);
238   }
239 };
240 
241 } // end anonymous namespace
242 
243 /// Return a vector shuffle operation which
244 /// performs the same shuffle in terms of order or result bytes, but on a type
245 /// whose vector element type is narrower than the original shuffle type.
246 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
247 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
248     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
249     ArrayRef<int> Mask) const {
250   unsigned NumMaskElts = VT.getVectorNumElements();
251   unsigned NumDestElts = NVT.getVectorNumElements();
252   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
253 
254   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
255 
256   if (NumEltsGrowth == 1)
257     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
258 
259   SmallVector<int, 8> NewMask;
260   for (unsigned i = 0; i != NumMaskElts; ++i) {
261     int Idx = Mask[i];
262     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
263       if (Idx < 0)
264         NewMask.push_back(-1);
265       else
266         NewMask.push_back(Idx * NumEltsGrowth + j);
267     }
268   }
269   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
270   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
271   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
272 }
273 
274 /// Expands the ConstantFP node to an integer constant or
275 /// a load from the constant pool.
276 SDValue
277 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
278   bool Extend = false;
279   SDLoc dl(CFP);
280 
281   // If a FP immediate is precise when represented as a float and if the
282   // target can do an extending load from float to double, we put it into
283   // the constant pool as a float, even if it's is statically typed as a
284   // double.  This shrinks FP constants and canonicalizes them for targets where
285   // an FP extending load is the same cost as a normal load (such as on the x87
286   // fp stack or PPC FP unit).
287   EVT VT = CFP->getValueType(0);
288   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
289   if (!UseCP) {
290     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
291     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
292                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
293   }
294 
295   APFloat APF = CFP->getValueAPF();
296   EVT OrigVT = VT;
297   EVT SVT = VT;
298 
299   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
300   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
301   if (!APF.isSignaling()) {
302     while (SVT != MVT::f32 && SVT != MVT::f16) {
303       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
304       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
305           // Only do this if the target has a native EXTLOAD instruction from
306           // smaller type.
307           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
308           TLI.ShouldShrinkFPConstant(OrigVT)) {
309         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
310         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
311         VT = SVT;
312         Extend = true;
313       }
314     }
315   }
316 
317   SDValue CPIdx =
318       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
319   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
320   if (Extend) {
321     SDValue Result = DAG.getExtLoad(
322         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
323         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
324         Alignment);
325     return Result;
326   }
327   SDValue Result = DAG.getLoad(
328       OrigVT, dl, DAG.getEntryNode(), CPIdx,
329       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
330   return Result;
331 }
332 
333 /// Expands the Constant node to a load from the constant pool.
334 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
335   SDLoc dl(CP);
336   EVT VT = CP->getValueType(0);
337   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
338                                       TLI.getPointerTy(DAG.getDataLayout()));
339   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
340   SDValue Result = DAG.getLoad(
341       VT, dl, DAG.getEntryNode(), CPIdx,
342       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
343   return Result;
344 }
345 
346 /// Some target cannot handle a variable insertion index for the
347 /// INSERT_VECTOR_ELT instruction.  In this case, it
348 /// is necessary to spill the vector being inserted into to memory, perform
349 /// the insert there, and then read the result back.
350 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
351                                                              SDValue Val,
352                                                              SDValue Idx,
353                                                              const SDLoc &dl) {
354   SDValue Tmp1 = Vec;
355   SDValue Tmp2 = Val;
356   SDValue Tmp3 = Idx;
357 
358   // If the target doesn't support this, we have to spill the input vector
359   // to a temporary stack slot, update the element, then reload it.  This is
360   // badness.  We could also load the value into a vector register (either
361   // with a "move to register" or "extload into register" instruction, then
362   // permute it into place, if the idx is a constant and if the idx is
363   // supported by the target.
364   EVT VT    = Tmp1.getValueType();
365   EVT EltVT = VT.getVectorElementType();
366   SDValue StackPtr = DAG.CreateStackTemporary(VT);
367 
368   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
369 
370   // Store the vector.
371   SDValue Ch = DAG.getStore(
372       DAG.getEntryNode(), dl, Tmp1, StackPtr,
373       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
374 
375   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
376 
377   // Store the scalar value.
378   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT);
379   // Load the updated vector.
380   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
381                                                DAG.getMachineFunction(), SPFI));
382 }
383 
384 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
385                                                       SDValue Idx,
386                                                       const SDLoc &dl) {
387   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
388     // SCALAR_TO_VECTOR requires that the type of the value being inserted
389     // match the element type of the vector being created, except for
390     // integers in which case the inserted value can be over width.
391     EVT EltVT = Vec.getValueType().getVectorElementType();
392     if (Val.getValueType() == EltVT ||
393         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
394       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
395                                   Vec.getValueType(), Val);
396 
397       unsigned NumElts = Vec.getValueType().getVectorNumElements();
398       // We generate a shuffle of InVec and ScVec, so the shuffle mask
399       // should be 0,1,2,3,4,5... with the appropriate element replaced with
400       // elt 0 of the RHS.
401       SmallVector<int, 8> ShufOps;
402       for (unsigned i = 0; i != NumElts; ++i)
403         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
404 
405       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
406     }
407   }
408   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
409 }
410 
411 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
412   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
413   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
414   // FIXME: We shouldn't do this for TargetConstantFP's.
415   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
416   // to phase ordering between legalized code and the dag combiner.  This
417   // probably means that we need to integrate dag combiner and legalizer
418   // together.
419   // We generally can't do this one for long doubles.
420   SDValue Chain = ST->getChain();
421   SDValue Ptr = ST->getBasePtr();
422   unsigned Alignment = ST->getAlignment();
423   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
424   AAMDNodes AAInfo = ST->getAAInfo();
425   SDLoc dl(ST);
426   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
427     if (CFP->getValueType(0) == MVT::f32 &&
428         TLI.isTypeLegal(MVT::i32)) {
429       SDValue Con = DAG.getConstant(CFP->getValueAPF().
430                                       bitcastToAPInt().zextOrTrunc(32),
431                                     SDLoc(CFP), MVT::i32);
432       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(), Alignment,
433                           MMOFlags, AAInfo);
434     }
435 
436     if (CFP->getValueType(0) == MVT::f64) {
437       // If this target supports 64-bit registers, do a single 64-bit store.
438       if (TLI.isTypeLegal(MVT::i64)) {
439         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
440                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
441         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
442                             Alignment, MMOFlags, AAInfo);
443       }
444 
445       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
446         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
447         // stores.  If the target supports neither 32- nor 64-bits, this
448         // xform is certainly not worth it.
449         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
450         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
451         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
452         if (DAG.getDataLayout().isBigEndian())
453           std::swap(Lo, Hi);
454 
455         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), Alignment,
456                           MMOFlags, AAInfo);
457         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
458                           DAG.getConstant(4, dl, Ptr.getValueType()));
459         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
460                           ST->getPointerInfo().getWithOffset(4),
461                           MinAlign(Alignment, 4U), MMOFlags, AAInfo);
462 
463         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
464       }
465     }
466   }
467   return SDValue(nullptr, 0);
468 }
469 
470 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
471   StoreSDNode *ST = cast<StoreSDNode>(Node);
472   SDValue Chain = ST->getChain();
473   SDValue Ptr = ST->getBasePtr();
474   SDLoc dl(Node);
475 
476   unsigned Alignment = ST->getAlignment();
477   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
478   AAMDNodes AAInfo = ST->getAAInfo();
479 
480   if (!ST->isTruncatingStore()) {
481     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
482     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
483       ReplaceNode(ST, OptStore);
484       return;
485     }
486 
487     SDValue Value = ST->getValue();
488     MVT VT = Value.getSimpleValueType();
489     switch (TLI.getOperationAction(ISD::STORE, VT)) {
490     default: llvm_unreachable("This action is not supported yet!");
491     case TargetLowering::Legal: {
492       // If this is an unaligned store and the target doesn't support it,
493       // expand it.
494       EVT MemVT = ST->getMemoryVT();
495       unsigned AS = ST->getAddressSpace();
496       unsigned Align = ST->getAlignment();
497       const DataLayout &DL = DAG.getDataLayout();
498       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
499         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
500         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
501         ReplaceNode(SDValue(ST, 0), Result);
502       } else
503         LLVM_DEBUG(dbgs() << "Legal store\n");
504       break;
505     }
506     case TargetLowering::Custom: {
507       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
508       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
509       if (Res && Res != SDValue(Node, 0))
510         ReplaceNode(SDValue(Node, 0), Res);
511       return;
512     }
513     case TargetLowering::Promote: {
514       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
515       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
516              "Can only promote stores to same size type");
517       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
518       SDValue Result =
519           DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
520                        Alignment, MMOFlags, AAInfo);
521       ReplaceNode(SDValue(Node, 0), Result);
522       break;
523     }
524     }
525     return;
526   }
527 
528   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
529   SDValue Value = ST->getValue();
530   EVT StVT = ST->getMemoryVT();
531   unsigned StWidth = StVT.getSizeInBits();
532   auto &DL = DAG.getDataLayout();
533 
534   if (StWidth != StVT.getStoreSizeInBits()) {
535     // Promote to a byte-sized store with upper bits zero if not
536     // storing an integral number of bytes.  For example, promote
537     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
538     EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
539                                 StVT.getStoreSizeInBits());
540     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
541     SDValue Result =
542         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
543                           Alignment, MMOFlags, AAInfo);
544     ReplaceNode(SDValue(Node, 0), Result);
545   } else if (StWidth & (StWidth - 1)) {
546     // If not storing a power-of-2 number of bits, expand as two stores.
547     assert(!StVT.isVector() && "Unsupported truncstore!");
548     unsigned LogStWidth = Log2_32(StWidth);
549     assert(LogStWidth < 32);
550     unsigned RoundWidth = 1 << LogStWidth;
551     assert(RoundWidth < StWidth);
552     unsigned ExtraWidth = StWidth - RoundWidth;
553     assert(ExtraWidth < RoundWidth);
554     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
555            "Store size not an integral number of bytes!");
556     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
557     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
558     SDValue Lo, Hi;
559     unsigned IncrementSize;
560 
561     if (DL.isLittleEndian()) {
562       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
563       // Store the bottom RoundWidth bits.
564       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
565                              RoundVT, Alignment, MMOFlags, AAInfo);
566 
567       // Store the remaining ExtraWidth bits.
568       IncrementSize = RoundWidth / 8;
569       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
570                         DAG.getConstant(IncrementSize, dl,
571                                         Ptr.getValueType()));
572       Hi = DAG.getNode(
573           ISD::SRL, dl, Value.getValueType(), Value,
574           DAG.getConstant(RoundWidth, dl,
575                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
576       Hi = DAG.getTruncStore(
577           Chain, dl, Hi, Ptr,
578           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
579           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
580     } else {
581       // Big endian - avoid unaligned stores.
582       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
583       // Store the top RoundWidth bits.
584       Hi = DAG.getNode(
585           ISD::SRL, dl, Value.getValueType(), Value,
586           DAG.getConstant(ExtraWidth, dl,
587                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
588       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
589                              RoundVT, Alignment, MMOFlags, AAInfo);
590 
591       // Store the remaining ExtraWidth bits.
592       IncrementSize = RoundWidth / 8;
593       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
594                         DAG.getConstant(IncrementSize, dl,
595                                         Ptr.getValueType()));
596       Lo = DAG.getTruncStore(
597           Chain, dl, Value, Ptr,
598           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
599           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
600     }
601 
602     // The order of the stores doesn't matter.
603     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
604     ReplaceNode(SDValue(Node, 0), Result);
605   } else {
606     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
607     default: llvm_unreachable("This action is not supported yet!");
608     case TargetLowering::Legal: {
609       EVT MemVT = ST->getMemoryVT();
610       unsigned AS = ST->getAddressSpace();
611       unsigned Align = ST->getAlignment();
612       // If this is an unaligned store and the target doesn't support it,
613       // expand it.
614       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
615         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
616         ReplaceNode(SDValue(ST, 0), Result);
617       }
618       break;
619     }
620     case TargetLowering::Custom: {
621       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
622       if (Res && Res != SDValue(Node, 0))
623         ReplaceNode(SDValue(Node, 0), Res);
624       return;
625     }
626     case TargetLowering::Expand:
627       assert(!StVT.isVector() &&
628              "Vector Stores are handled in LegalizeVectorOps");
629 
630       SDValue Result;
631 
632       // TRUNCSTORE:i16 i32 -> STORE i16
633       if (TLI.isTypeLegal(StVT)) {
634         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
635         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
636                               Alignment, MMOFlags, AAInfo);
637       } else {
638         // The in-memory type isn't legal. Truncate to the type it would promote
639         // to, and then do a truncstore.
640         Value = DAG.getNode(ISD::TRUNCATE, dl,
641                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
642                             Value);
643         Result = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
644                                    StVT, Alignment, MMOFlags, AAInfo);
645       }
646 
647       ReplaceNode(SDValue(Node, 0), Result);
648       break;
649     }
650   }
651 }
652 
653 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
654   LoadSDNode *LD = cast<LoadSDNode>(Node);
655   SDValue Chain = LD->getChain();  // The chain.
656   SDValue Ptr = LD->getBasePtr();  // The base pointer.
657   SDValue Value;                   // The value returned by the load op.
658   SDLoc dl(Node);
659 
660   ISD::LoadExtType ExtType = LD->getExtensionType();
661   if (ExtType == ISD::NON_EXTLOAD) {
662     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
663     MVT VT = Node->getSimpleValueType(0);
664     SDValue RVal = SDValue(Node, 0);
665     SDValue RChain = SDValue(Node, 1);
666 
667     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
668     default: llvm_unreachable("This action is not supported yet!");
669     case TargetLowering::Legal: {
670       EVT MemVT = LD->getMemoryVT();
671       unsigned AS = LD->getAddressSpace();
672       unsigned Align = LD->getAlignment();
673       const DataLayout &DL = DAG.getDataLayout();
674       // If this is an unaligned load and the target doesn't support it,
675       // expand it.
676       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
677         std::tie(RVal, RChain) =  TLI.expandUnalignedLoad(LD, DAG);
678       }
679       break;
680     }
681     case TargetLowering::Custom:
682       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
683         RVal = Res;
684         RChain = Res.getValue(1);
685       }
686       break;
687 
688     case TargetLowering::Promote: {
689       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
690       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
691              "Can only promote loads to same size type");
692 
693       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
694       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
695       RChain = Res.getValue(1);
696       break;
697     }
698     }
699     if (RChain.getNode() != Node) {
700       assert(RVal.getNode() != Node && "Load must be completely replaced");
701       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
702       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
703       if (UpdatedNodes) {
704         UpdatedNodes->insert(RVal.getNode());
705         UpdatedNodes->insert(RChain.getNode());
706       }
707       ReplacedNode(Node);
708     }
709     return;
710   }
711 
712   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
713   EVT SrcVT = LD->getMemoryVT();
714   unsigned SrcWidth = SrcVT.getSizeInBits();
715   unsigned Alignment = LD->getAlignment();
716   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
717   AAMDNodes AAInfo = LD->getAAInfo();
718 
719   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
720       // Some targets pretend to have an i1 loading operation, and actually
721       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
722       // bits are guaranteed to be zero; it helps the optimizers understand
723       // that these bits are zero.  It is also useful for EXTLOAD, since it
724       // tells the optimizers that those bits are undefined.  It would be
725       // nice to have an effective generic way of getting these benefits...
726       // Until such a way is found, don't insist on promoting i1 here.
727       (SrcVT != MVT::i1 ||
728        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
729          TargetLowering::Promote)) {
730     // Promote to a byte-sized load if not loading an integral number of
731     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
732     unsigned NewWidth = SrcVT.getStoreSizeInBits();
733     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
734     SDValue Ch;
735 
736     // The extra bits are guaranteed to be zero, since we stored them that
737     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
738 
739     ISD::LoadExtType NewExtType =
740       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
741 
742     SDValue Result =
743         DAG.getExtLoad(NewExtType, dl, Node->getValueType(0), Chain, Ptr,
744                        LD->getPointerInfo(), NVT, Alignment, MMOFlags, AAInfo);
745 
746     Ch = Result.getValue(1); // The chain.
747 
748     if (ExtType == ISD::SEXTLOAD)
749       // Having the top bits zero doesn't help when sign extending.
750       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
751                            Result.getValueType(),
752                            Result, DAG.getValueType(SrcVT));
753     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
754       // All the top bits are guaranteed to be zero - inform the optimizers.
755       Result = DAG.getNode(ISD::AssertZext, dl,
756                            Result.getValueType(), Result,
757                            DAG.getValueType(SrcVT));
758 
759     Value = Result;
760     Chain = Ch;
761   } else if (SrcWidth & (SrcWidth - 1)) {
762     // If not loading a power-of-2 number of bits, expand as two loads.
763     assert(!SrcVT.isVector() && "Unsupported extload!");
764     unsigned LogSrcWidth = Log2_32(SrcWidth);
765     assert(LogSrcWidth < 32);
766     unsigned RoundWidth = 1 << LogSrcWidth;
767     assert(RoundWidth < SrcWidth);
768     unsigned ExtraWidth = SrcWidth - RoundWidth;
769     assert(ExtraWidth < RoundWidth);
770     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
771            "Load size not an integral number of bytes!");
772     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
773     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
774     SDValue Lo, Hi, Ch;
775     unsigned IncrementSize;
776     auto &DL = DAG.getDataLayout();
777 
778     if (DL.isLittleEndian()) {
779       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
780       // Load the bottom RoundWidth bits.
781       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
782                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
783                           AAInfo);
784 
785       // Load the remaining ExtraWidth bits.
786       IncrementSize = RoundWidth / 8;
787       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
788                          DAG.getConstant(IncrementSize, dl,
789                                          Ptr.getValueType()));
790       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
791                           LD->getPointerInfo().getWithOffset(IncrementSize),
792                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
793                           AAInfo);
794 
795       // Build a factor node to remember that this load is independent of
796       // the other one.
797       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
798                        Hi.getValue(1));
799 
800       // Move the top bits to the right place.
801       Hi = DAG.getNode(
802           ISD::SHL, dl, Hi.getValueType(), Hi,
803           DAG.getConstant(RoundWidth, dl,
804                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
805 
806       // Join the hi and lo parts.
807       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
808     } else {
809       // Big endian - avoid unaligned loads.
810       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
811       // Load the top RoundWidth bits.
812       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
813                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
814                           AAInfo);
815 
816       // Load the remaining ExtraWidth bits.
817       IncrementSize = RoundWidth / 8;
818       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
819                          DAG.getConstant(IncrementSize, dl,
820                                          Ptr.getValueType()));
821       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
822                           LD->getPointerInfo().getWithOffset(IncrementSize),
823                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
824                           AAInfo);
825 
826       // Build a factor node to remember that this load is independent of
827       // the other one.
828       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
829                        Hi.getValue(1));
830 
831       // Move the top bits to the right place.
832       Hi = DAG.getNode(
833           ISD::SHL, dl, Hi.getValueType(), Hi,
834           DAG.getConstant(ExtraWidth, dl,
835                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
836 
837       // Join the hi and lo parts.
838       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
839     }
840 
841     Chain = Ch;
842   } else {
843     bool isCustom = false;
844     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
845                                  SrcVT.getSimpleVT())) {
846     default: llvm_unreachable("This action is not supported yet!");
847     case TargetLowering::Custom:
848       isCustom = true;
849       LLVM_FALLTHROUGH;
850     case TargetLowering::Legal:
851       Value = SDValue(Node, 0);
852       Chain = SDValue(Node, 1);
853 
854       if (isCustom) {
855         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
856           Value = Res;
857           Chain = Res.getValue(1);
858         }
859       } else {
860         // If this is an unaligned load and the target doesn't support it,
861         // expand it.
862         EVT MemVT = LD->getMemoryVT();
863         unsigned AS = LD->getAddressSpace();
864         unsigned Align = LD->getAlignment();
865         const DataLayout &DL = DAG.getDataLayout();
866         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
867           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
868         }
869       }
870       break;
871 
872     case TargetLowering::Expand: {
873       EVT DestVT = Node->getValueType(0);
874       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
875         // If the source type is not legal, see if there is a legal extload to
876         // an intermediate type that we can then extend further.
877         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
878         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
879             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
880           // If we are loading a legal type, this is a non-extload followed by a
881           // full extend.
882           ISD::LoadExtType MidExtType =
883               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
884 
885           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
886                                         SrcVT, LD->getMemOperand());
887           unsigned ExtendOp =
888               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
889           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
890           Chain = Load.getValue(1);
891           break;
892         }
893 
894         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
895         // normal undefined upper bits behavior to allow using an in-reg extend
896         // with the illegal FP type, so load as an integer and do the
897         // from-integer conversion.
898         if (SrcVT.getScalarType() == MVT::f16) {
899           EVT ISrcVT = SrcVT.changeTypeToInteger();
900           EVT IDestVT = DestVT.changeTypeToInteger();
901           EVT LoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
902 
903           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, LoadVT,
904                                           Chain, Ptr, ISrcVT,
905                                           LD->getMemOperand());
906           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
907           Chain = Result.getValue(1);
908           break;
909         }
910       }
911 
912       assert(!SrcVT.isVector() &&
913              "Vector Loads are handled in LegalizeVectorOps");
914 
915       // FIXME: This does not work for vectors on most targets.  Sign-
916       // and zero-extend operations are currently folded into extending
917       // loads, whether they are legal or not, and then we end up here
918       // without any support for legalizing them.
919       assert(ExtType != ISD::EXTLOAD &&
920              "EXTLOAD should always be supported!");
921       // Turn the unsupported load into an EXTLOAD followed by an
922       // explicit zero/sign extend inreg.
923       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
924                                       Node->getValueType(0),
925                                       Chain, Ptr, SrcVT,
926                                       LD->getMemOperand());
927       SDValue ValRes;
928       if (ExtType == ISD::SEXTLOAD)
929         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
930                              Result.getValueType(),
931                              Result, DAG.getValueType(SrcVT));
932       else
933         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
934       Value = ValRes;
935       Chain = Result.getValue(1);
936       break;
937     }
938     }
939   }
940 
941   // Since loads produce two values, make sure to remember that we legalized
942   // both of them.
943   if (Chain.getNode() != Node) {
944     assert(Value.getNode() != Node && "Load must be completely replaced");
945     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
946     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
947     if (UpdatedNodes) {
948       UpdatedNodes->insert(Value.getNode());
949       UpdatedNodes->insert(Chain.getNode());
950     }
951     ReplacedNode(Node);
952   }
953 }
954 
955 /// Return a legal replacement for the given operation, with all legal operands.
956 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
957   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
958 
959   // Allow illegal target nodes and illegal registers.
960   if (Node->getOpcode() == ISD::TargetConstant ||
961       Node->getOpcode() == ISD::Register)
962     return;
963 
964 #ifndef NDEBUG
965   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
966     assert((TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
967               TargetLowering::TypeLegal ||
968             TLI.isTypeLegal(Node->getValueType(i))) &&
969            "Unexpected illegal type!");
970 
971   for (const SDValue &Op : Node->op_values())
972     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
973               TargetLowering::TypeLegal ||
974             TLI.isTypeLegal(Op.getValueType()) ||
975             Op.getOpcode() == ISD::TargetConstant ||
976             Op.getOpcode() == ISD::Register) &&
977             "Unexpected illegal type!");
978 #endif
979 
980   // Figure out the correct action; the way to query this varies by opcode
981   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
982   bool SimpleFinishLegalizing = true;
983   switch (Node->getOpcode()) {
984   case ISD::INTRINSIC_W_CHAIN:
985   case ISD::INTRINSIC_WO_CHAIN:
986   case ISD::INTRINSIC_VOID:
987   case ISD::STACKSAVE:
988     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
989     break;
990   case ISD::GET_DYNAMIC_AREA_OFFSET:
991     Action = TLI.getOperationAction(Node->getOpcode(),
992                                     Node->getValueType(0));
993     break;
994   case ISD::VAARG:
995     Action = TLI.getOperationAction(Node->getOpcode(),
996                                     Node->getValueType(0));
997     if (Action != TargetLowering::Promote)
998       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
999     break;
1000   case ISD::FP_TO_FP16:
1001   case ISD::SINT_TO_FP:
1002   case ISD::UINT_TO_FP:
1003   case ISD::EXTRACT_VECTOR_ELT:
1004   case ISD::LROUND:
1005   case ISD::LLROUND:
1006   case ISD::LRINT:
1007   case ISD::LLRINT:
1008     Action = TLI.getOperationAction(Node->getOpcode(),
1009                                     Node->getOperand(0).getValueType());
1010     break;
1011   case ISD::FP_ROUND_INREG:
1012   case ISD::SIGN_EXTEND_INREG: {
1013     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1014     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1015     break;
1016   }
1017   case ISD::ATOMIC_STORE:
1018     Action = TLI.getOperationAction(Node->getOpcode(),
1019                                     Node->getOperand(2).getValueType());
1020     break;
1021   case ISD::SELECT_CC:
1022   case ISD::SETCC:
1023   case ISD::BR_CC: {
1024     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1025                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1026     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
1027     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1028     ISD::CondCode CCCode =
1029         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1030     Action = TLI.getCondCodeAction(CCCode, OpVT);
1031     if (Action == TargetLowering::Legal) {
1032       if (Node->getOpcode() == ISD::SELECT_CC)
1033         Action = TLI.getOperationAction(Node->getOpcode(),
1034                                         Node->getValueType(0));
1035       else
1036         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1037     }
1038     break;
1039   }
1040   case ISD::LOAD:
1041   case ISD::STORE:
1042     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1043     // STORE expects the unlegalized operand in some cases.
1044     SimpleFinishLegalizing = false;
1045     break;
1046   case ISD::CALLSEQ_START:
1047   case ISD::CALLSEQ_END:
1048     // FIXME: This shouldn't be necessary.  These nodes have special properties
1049     // dealing with the recursive nature of legalization.  Removing this
1050     // special case should be done as part of making LegalizeDAG non-recursive.
1051     SimpleFinishLegalizing = false;
1052     break;
1053   case ISD::EXTRACT_ELEMENT:
1054   case ISD::FLT_ROUNDS_:
1055   case ISD::MERGE_VALUES:
1056   case ISD::EH_RETURN:
1057   case ISD::FRAME_TO_ARGS_OFFSET:
1058   case ISD::EH_DWARF_CFA:
1059   case ISD::EH_SJLJ_SETJMP:
1060   case ISD::EH_SJLJ_LONGJMP:
1061   case ISD::EH_SJLJ_SETUP_DISPATCH:
1062     // These operations lie about being legal: when they claim to be legal,
1063     // they should actually be expanded.
1064     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1065     if (Action == TargetLowering::Legal)
1066       Action = TargetLowering::Expand;
1067     break;
1068   case ISD::INIT_TRAMPOLINE:
1069   case ISD::ADJUST_TRAMPOLINE:
1070   case ISD::FRAMEADDR:
1071   case ISD::RETURNADDR:
1072   case ISD::ADDROFRETURNADDR:
1073   case ISD::SPONENTRY:
1074     // These operations lie about being legal: when they claim to be legal,
1075     // they should actually be custom-lowered.
1076     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1077     if (Action == TargetLowering::Legal)
1078       Action = TargetLowering::Custom;
1079     break;
1080   case ISD::READCYCLECOUNTER:
1081     // READCYCLECOUNTER returns an i64, even if type legalization might have
1082     // expanded that to several smaller types.
1083     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1084     break;
1085   case ISD::READ_REGISTER:
1086   case ISD::WRITE_REGISTER:
1087     // Named register is legal in the DAG, but blocked by register name
1088     // selection if not implemented by target (to chose the correct register)
1089     // They'll be converted to Copy(To/From)Reg.
1090     Action = TargetLowering::Legal;
1091     break;
1092   case ISD::DEBUGTRAP:
1093     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1094     if (Action == TargetLowering::Expand) {
1095       // replace ISD::DEBUGTRAP with ISD::TRAP
1096       SDValue NewVal;
1097       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1098                            Node->getOperand(0));
1099       ReplaceNode(Node, NewVal.getNode());
1100       LegalizeOp(NewVal.getNode());
1101       return;
1102     }
1103     break;
1104   case ISD::STRICT_FADD:
1105   case ISD::STRICT_FSUB:
1106   case ISD::STRICT_FMUL:
1107   case ISD::STRICT_FDIV:
1108   case ISD::STRICT_FREM:
1109   case ISD::STRICT_FSQRT:
1110   case ISD::STRICT_FMA:
1111   case ISD::STRICT_FPOW:
1112   case ISD::STRICT_FPOWI:
1113   case ISD::STRICT_FSIN:
1114   case ISD::STRICT_FCOS:
1115   case ISD::STRICT_FEXP:
1116   case ISD::STRICT_FEXP2:
1117   case ISD::STRICT_FLOG:
1118   case ISD::STRICT_FLOG10:
1119   case ISD::STRICT_FLOG2:
1120   case ISD::STRICT_FRINT:
1121   case ISD::STRICT_FNEARBYINT:
1122   case ISD::STRICT_FMAXNUM:
1123   case ISD::STRICT_FMINNUM:
1124   case ISD::STRICT_FCEIL:
1125   case ISD::STRICT_FFLOOR:
1126   case ISD::STRICT_FROUND:
1127   case ISD::STRICT_FTRUNC:
1128   case ISD::STRICT_FP_ROUND:
1129   case ISD::STRICT_FP_EXTEND:
1130     // These pseudo-ops get legalized as if they were their non-strict
1131     // equivalent.  For instance, if ISD::FSQRT is legal then ISD::STRICT_FSQRT
1132     // is also legal, but if ISD::FSQRT requires expansion then so does
1133     // ISD::STRICT_FSQRT.
1134     Action = TLI.getStrictFPOperationAction(Node->getOpcode(),
1135                                             Node->getValueType(0));
1136     break;
1137   case ISD::SADDSAT:
1138   case ISD::UADDSAT:
1139   case ISD::SSUBSAT:
1140   case ISD::USUBSAT: {
1141     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1142     break;
1143   }
1144   case ISD::SMULFIX:
1145   case ISD::SMULFIXSAT:
1146   case ISD::UMULFIX: {
1147     unsigned Scale = Node->getConstantOperandVal(2);
1148     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1149                                               Node->getValueType(0), Scale);
1150     break;
1151   }
1152   case ISD::MSCATTER:
1153     Action = TLI.getOperationAction(Node->getOpcode(),
1154                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1155     break;
1156   case ISD::MSTORE:
1157     Action = TLI.getOperationAction(Node->getOpcode(),
1158                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1159     break;
1160   case ISD::VECREDUCE_FADD:
1161   case ISD::VECREDUCE_FMUL:
1162   case ISD::VECREDUCE_ADD:
1163   case ISD::VECREDUCE_MUL:
1164   case ISD::VECREDUCE_AND:
1165   case ISD::VECREDUCE_OR:
1166   case ISD::VECREDUCE_XOR:
1167   case ISD::VECREDUCE_SMAX:
1168   case ISD::VECREDUCE_SMIN:
1169   case ISD::VECREDUCE_UMAX:
1170   case ISD::VECREDUCE_UMIN:
1171   case ISD::VECREDUCE_FMAX:
1172   case ISD::VECREDUCE_FMIN:
1173     Action = TLI.getOperationAction(
1174         Node->getOpcode(), Node->getOperand(0).getValueType());
1175     break;
1176   default:
1177     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1178       Action = TargetLowering::Legal;
1179     } else {
1180       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1181     }
1182     break;
1183   }
1184 
1185   if (SimpleFinishLegalizing) {
1186     SDNode *NewNode = Node;
1187     switch (Node->getOpcode()) {
1188     default: break;
1189     case ISD::SHL:
1190     case ISD::SRL:
1191     case ISD::SRA:
1192     case ISD::ROTL:
1193     case ISD::ROTR: {
1194       // Legalizing shifts/rotates requires adjusting the shift amount
1195       // to the appropriate width.
1196       SDValue Op0 = Node->getOperand(0);
1197       SDValue Op1 = Node->getOperand(1);
1198       if (!Op1.getValueType().isVector()) {
1199         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1200         // The getShiftAmountOperand() may create a new operand node or
1201         // return the existing one. If new operand is created we need
1202         // to update the parent node.
1203         // Do not try to legalize SAO here! It will be automatically legalized
1204         // in the next round.
1205         if (SAO != Op1)
1206           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1207       }
1208     }
1209     break;
1210     case ISD::FSHL:
1211     case ISD::FSHR:
1212     case ISD::SRL_PARTS:
1213     case ISD::SRA_PARTS:
1214     case ISD::SHL_PARTS: {
1215       // Legalizing shifts/rotates requires adjusting the shift amount
1216       // to the appropriate width.
1217       SDValue Op0 = Node->getOperand(0);
1218       SDValue Op1 = Node->getOperand(1);
1219       SDValue Op2 = Node->getOperand(2);
1220       if (!Op2.getValueType().isVector()) {
1221         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1222         // The getShiftAmountOperand() may create a new operand node or
1223         // return the existing one. If new operand is created we need
1224         // to update the parent node.
1225         if (SAO != Op2)
1226           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1227       }
1228       break;
1229     }
1230     }
1231 
1232     if (NewNode != Node) {
1233       ReplaceNode(Node, NewNode);
1234       Node = NewNode;
1235     }
1236     switch (Action) {
1237     case TargetLowering::Legal:
1238       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1239       return;
1240     case TargetLowering::Custom:
1241       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1242       // FIXME: The handling for custom lowering with multiple results is
1243       // a complete mess.
1244       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1245         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1246           return;
1247 
1248         if (Node->getNumValues() == 1) {
1249           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1250           // We can just directly replace this node with the lowered value.
1251           ReplaceNode(SDValue(Node, 0), Res);
1252           return;
1253         }
1254 
1255         SmallVector<SDValue, 8> ResultVals;
1256         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1257           ResultVals.push_back(Res.getValue(i));
1258         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1259         ReplaceNode(Node, ResultVals.data());
1260         return;
1261       }
1262       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1263       LLVM_FALLTHROUGH;
1264     case TargetLowering::Expand:
1265       if (ExpandNode(Node))
1266         return;
1267       LLVM_FALLTHROUGH;
1268     case TargetLowering::LibCall:
1269       ConvertNodeToLibcall(Node);
1270       return;
1271     case TargetLowering::Promote:
1272       PromoteNode(Node);
1273       return;
1274     }
1275   }
1276 
1277   switch (Node->getOpcode()) {
1278   default:
1279 #ifndef NDEBUG
1280     dbgs() << "NODE: ";
1281     Node->dump( &DAG);
1282     dbgs() << "\n";
1283 #endif
1284     llvm_unreachable("Do not know how to legalize this operator!");
1285 
1286   case ISD::CALLSEQ_START:
1287   case ISD::CALLSEQ_END:
1288     break;
1289   case ISD::LOAD:
1290     return LegalizeLoadOps(Node);
1291   case ISD::STORE:
1292     return LegalizeStoreOps(Node);
1293   }
1294 }
1295 
1296 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1297   SDValue Vec = Op.getOperand(0);
1298   SDValue Idx = Op.getOperand(1);
1299   SDLoc dl(Op);
1300 
1301   // Before we generate a new store to a temporary stack slot, see if there is
1302   // already one that we can use. There often is because when we scalarize
1303   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1304   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1305   // the vector. If all are expanded here, we don't want one store per vector
1306   // element.
1307 
1308   // Caches for hasPredecessorHelper
1309   SmallPtrSet<const SDNode *, 32> Visited;
1310   SmallVector<const SDNode *, 16> Worklist;
1311   Visited.insert(Op.getNode());
1312   Worklist.push_back(Idx.getNode());
1313   SDValue StackPtr, Ch;
1314   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1315        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1316     SDNode *User = *UI;
1317     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1318       if (ST->isIndexed() || ST->isTruncatingStore() ||
1319           ST->getValue() != Vec)
1320         continue;
1321 
1322       // Make sure that nothing else could have stored into the destination of
1323       // this store.
1324       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1325         continue;
1326 
1327       // If the index is dependent on the store we will introduce a cycle when
1328       // creating the load (the load uses the index, and by replacing the chain
1329       // we will make the index dependent on the load). Also, the store might be
1330       // dependent on the extractelement and introduce a cycle when creating
1331       // the load.
1332       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1333           ST->hasPredecessor(Op.getNode()))
1334         continue;
1335 
1336       StackPtr = ST->getBasePtr();
1337       Ch = SDValue(ST, 0);
1338       break;
1339     }
1340   }
1341 
1342   EVT VecVT = Vec.getValueType();
1343 
1344   if (!Ch.getNode()) {
1345     // Store the value to a temporary stack slot, then LOAD the returned part.
1346     StackPtr = DAG.CreateStackTemporary(VecVT);
1347     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1348                       MachinePointerInfo());
1349   }
1350 
1351   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1352 
1353   SDValue NewLoad;
1354 
1355   if (Op.getValueType().isVector())
1356     NewLoad =
1357         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1358   else
1359     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1360                              MachinePointerInfo(),
1361                              VecVT.getVectorElementType());
1362 
1363   // Replace the chain going out of the store, by the one out of the load.
1364   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1365 
1366   // We introduced a cycle though, so update the loads operands, making sure
1367   // to use the original store's chain as an incoming chain.
1368   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1369                                           NewLoad->op_end());
1370   NewLoadOperands[0] = Ch;
1371   NewLoad =
1372       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1373   return NewLoad;
1374 }
1375 
1376 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1377   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1378 
1379   SDValue Vec  = Op.getOperand(0);
1380   SDValue Part = Op.getOperand(1);
1381   SDValue Idx  = Op.getOperand(2);
1382   SDLoc dl(Op);
1383 
1384   // Store the value to a temporary stack slot, then LOAD the returned part.
1385   EVT VecVT = Vec.getValueType();
1386   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1387   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1388   MachinePointerInfo PtrInfo =
1389       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1390 
1391   // First store the whole vector.
1392   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1393 
1394   // Then store the inserted part.
1395   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1396 
1397   // Store the subvector.
1398   Ch = DAG.getStore(Ch, dl, Part, SubStackPtr, MachinePointerInfo());
1399 
1400   // Finally, load the updated vector.
1401   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1402 }
1403 
1404 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1405   // We can't handle this case efficiently.  Allocate a sufficiently
1406   // aligned object on the stack, store each element into it, then load
1407   // the result as a vector.
1408   // Create the stack frame object.
1409   EVT VT = Node->getValueType(0);
1410   EVT EltVT = VT.getVectorElementType();
1411   SDLoc dl(Node);
1412   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1413   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1414   MachinePointerInfo PtrInfo =
1415       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1416 
1417   // Emit a store of each element to the stack slot.
1418   SmallVector<SDValue, 8> Stores;
1419   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
1420   assert(TypeByteSize > 0 && "Vector element type too small for stack store!");
1421   // Store (in the right endianness) the elements to memory.
1422   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1423     // Ignore undef elements.
1424     if (Node->getOperand(i).isUndef()) continue;
1425 
1426     unsigned Offset = TypeByteSize*i;
1427 
1428     SDValue Idx = DAG.getConstant(Offset, dl, FIPtr.getValueType());
1429     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
1430 
1431     // If the destination vector element type is narrower than the source
1432     // element type, only store the bits necessary.
1433     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
1434       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1435                                          Node->getOperand(i), Idx,
1436                                          PtrInfo.getWithOffset(Offset), EltVT));
1437     } else
1438       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1439                                     Idx, PtrInfo.getWithOffset(Offset)));
1440   }
1441 
1442   SDValue StoreChain;
1443   if (!Stores.empty())    // Not all undef elements?
1444     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1445   else
1446     StoreChain = DAG.getEntryNode();
1447 
1448   // Result is a load from the stack slot.
1449   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1450 }
1451 
1452 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1453 /// containing the sign bit if the target has no integer value capable of
1454 /// holding all bits of the floating-point value.
1455 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1456                                              const SDLoc &DL,
1457                                              SDValue Value) const {
1458   EVT FloatVT = Value.getValueType();
1459   unsigned NumBits = FloatVT.getSizeInBits();
1460   State.FloatVT = FloatVT;
1461   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1462   // Convert to an integer of the same size.
1463   if (TLI.isTypeLegal(IVT)) {
1464     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1465     State.SignMask = APInt::getSignMask(NumBits);
1466     State.SignBit = NumBits - 1;
1467     return;
1468   }
1469 
1470   auto &DataLayout = DAG.getDataLayout();
1471   // Store the float to memory, then load the sign part out as an integer.
1472   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1473   // First create a temporary that is aligned for both the load and store.
1474   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1475   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1476   // Then store the float to it.
1477   State.FloatPtr = StackPtr;
1478   MachineFunction &MF = DAG.getMachineFunction();
1479   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1480   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1481                              State.FloatPointerInfo);
1482 
1483   SDValue IntPtr;
1484   if (DataLayout.isBigEndian()) {
1485     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1486     // Load out a legal integer with the same sign bit as the float.
1487     IntPtr = StackPtr;
1488     State.IntPointerInfo = State.FloatPointerInfo;
1489   } else {
1490     // Advance the pointer so that the loaded byte will contain the sign bit.
1491     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1492     IntPtr = DAG.getNode(ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
1493                       DAG.getConstant(ByteOffset, DL, StackPtr.getValueType()));
1494     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1495                                                              ByteOffset);
1496   }
1497 
1498   State.IntPtr = IntPtr;
1499   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1500                                   State.IntPointerInfo, MVT::i8);
1501   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1502   State.SignBit = 7;
1503 }
1504 
1505 /// Replace the integer value produced by getSignAsIntValue() with a new value
1506 /// and cast the result back to a floating-point type.
1507 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1508                                               const SDLoc &DL,
1509                                               SDValue NewIntValue) const {
1510   if (!State.Chain)
1511     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1512 
1513   // Override the part containing the sign bit in the value stored on the stack.
1514   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1515                                     State.IntPointerInfo, MVT::i8);
1516   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1517                      State.FloatPointerInfo);
1518 }
1519 
1520 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1521   SDLoc DL(Node);
1522   SDValue Mag = Node->getOperand(0);
1523   SDValue Sign = Node->getOperand(1);
1524 
1525   // Get sign bit into an integer value.
1526   FloatSignAsInt SignAsInt;
1527   getSignAsIntValue(SignAsInt, DL, Sign);
1528 
1529   EVT IntVT = SignAsInt.IntValue.getValueType();
1530   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1531   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1532                                 SignMask);
1533 
1534   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1535   EVT FloatVT = Mag.getValueType();
1536   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1537       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1538     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1539     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1540     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1541                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1542     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1543   }
1544 
1545   // Transform Mag value to integer, and clear the sign bit.
1546   FloatSignAsInt MagAsInt;
1547   getSignAsIntValue(MagAsInt, DL, Mag);
1548   EVT MagVT = MagAsInt.IntValue.getValueType();
1549   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1550   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1551                                     ClearSignMask);
1552 
1553   // Get the signbit at the right position for MagAsInt.
1554   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1555   EVT ShiftVT = IntVT;
1556   if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1557     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1558     ShiftVT = MagVT;
1559   }
1560   if (ShiftAmount > 0) {
1561     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1562     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1563   } else if (ShiftAmount < 0) {
1564     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1565     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1566   }
1567   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1568     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1569   }
1570 
1571   // Store the part with the modified sign and convert back to float.
1572   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1573   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1574 }
1575 
1576 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1577   SDLoc DL(Node);
1578   SDValue Value = Node->getOperand(0);
1579 
1580   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1581   EVT FloatVT = Value.getValueType();
1582   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1583     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1584     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1585   }
1586 
1587   // Transform value to integer, clear the sign bit and transform back.
1588   FloatSignAsInt ValueAsInt;
1589   getSignAsIntValue(ValueAsInt, DL, Value);
1590   EVT IntVT = ValueAsInt.IntValue.getValueType();
1591   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1592   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1593                                     ClearSignMask);
1594   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1595 }
1596 
1597 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1598                                            SmallVectorImpl<SDValue> &Results) {
1599   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1600   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1601           " not tell us which reg is the stack pointer!");
1602   SDLoc dl(Node);
1603   EVT VT = Node->getValueType(0);
1604   SDValue Tmp1 = SDValue(Node, 0);
1605   SDValue Tmp2 = SDValue(Node, 1);
1606   SDValue Tmp3 = Node->getOperand(2);
1607   SDValue Chain = Tmp1.getOperand(0);
1608 
1609   // Chain the dynamic stack allocation so that it doesn't modify the stack
1610   // pointer when other instructions are using the stack.
1611   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1612 
1613   SDValue Size  = Tmp2.getOperand(1);
1614   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1615   Chain = SP.getValue(1);
1616   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
1617   unsigned StackAlign =
1618       DAG.getSubtarget().getFrameLowering()->getStackAlignment();
1619   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
1620   if (Align > StackAlign)
1621     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1622                        DAG.getConstant(-(uint64_t)Align, dl, VT));
1623   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1624 
1625   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1626                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1627 
1628   Results.push_back(Tmp1);
1629   Results.push_back(Tmp2);
1630 }
1631 
1632 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1633 /// target.
1634 ///
1635 /// If the SETCC has been legalized using AND / OR, then the legalized node
1636 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1637 /// will be set to false.
1638 ///
1639 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1640 /// then the values of LHS and RHS will be swapped, CC will be set to the
1641 /// new condition, and NeedInvert will be set to false.
1642 ///
1643 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1644 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1645 /// will be set to true. The caller must invert the result of the SETCC with
1646 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1647 /// of a true/false result.
1648 ///
1649 /// \returns true if the SetCC has been legalized, false if it hasn't.
1650 bool SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT, SDValue &LHS,
1651                                                  SDValue &RHS, SDValue &CC,
1652                                                  bool &NeedInvert,
1653                                                  const SDLoc &dl) {
1654   MVT OpVT = LHS.getSimpleValueType();
1655   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1656   NeedInvert = false;
1657   bool NeedSwap = false;
1658   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1659   default: llvm_unreachable("Unknown condition code action!");
1660   case TargetLowering::Legal:
1661     // Nothing to do.
1662     break;
1663   case TargetLowering::Expand: {
1664     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1665     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1666       std::swap(LHS, RHS);
1667       CC = DAG.getCondCode(InvCC);
1668       return true;
1669     }
1670     // Swapping operands didn't work. Try inverting the condition.
1671     InvCC = getSetCCInverse(CCCode, OpVT.isInteger());
1672     if (!TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1673       // If inverting the condition is not enough, try swapping operands
1674       // on top of it.
1675       InvCC = ISD::getSetCCSwappedOperands(InvCC);
1676       NeedSwap = true;
1677     }
1678     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1679       CC = DAG.getCondCode(InvCC);
1680       NeedInvert = true;
1681       if (NeedSwap)
1682         std::swap(LHS, RHS);
1683       return true;
1684     }
1685 
1686     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1687     unsigned Opc = 0;
1688     switch (CCCode) {
1689     default: llvm_unreachable("Don't know how to expand this condition!");
1690     case ISD::SETO:
1691         assert(TLI.isCondCodeLegal(ISD::SETOEQ, OpVT)
1692             && "If SETO is expanded, SETOEQ must be legal!");
1693         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1694     case ISD::SETUO:
1695         assert(TLI.isCondCodeLegal(ISD::SETUNE, OpVT)
1696             && "If SETUO is expanded, SETUNE must be legal!");
1697         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1698     case ISD::SETOEQ:
1699     case ISD::SETOGT:
1700     case ISD::SETOGE:
1701     case ISD::SETOLT:
1702     case ISD::SETOLE:
1703     case ISD::SETONE:
1704     case ISD::SETUEQ:
1705     case ISD::SETUNE:
1706     case ISD::SETUGT:
1707     case ISD::SETUGE:
1708     case ISD::SETULT:
1709     case ISD::SETULE:
1710         // If we are floating point, assign and break, otherwise fall through.
1711         if (!OpVT.isInteger()) {
1712           // We can use the 4th bit to tell if we are the unordered
1713           // or ordered version of the opcode.
1714           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1715           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1716           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1717           break;
1718         }
1719         // Fallthrough if we are unsigned integer.
1720         LLVM_FALLTHROUGH;
1721     case ISD::SETLE:
1722     case ISD::SETGT:
1723     case ISD::SETGE:
1724     case ISD::SETLT:
1725     case ISD::SETNE:
1726     case ISD::SETEQ:
1727       // If all combinations of inverting the condition and swapping operands
1728       // didn't work then we have no means to expand the condition.
1729       llvm_unreachable("Don't know how to expand this condition!");
1730     }
1731 
1732     SDValue SetCC1, SetCC2;
1733     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1734       // If we aren't the ordered or unorder operation,
1735       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1736       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
1737       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
1738     } else {
1739       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1740       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1);
1741       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2);
1742     }
1743     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1744     RHS = SDValue();
1745     CC  = SDValue();
1746     return true;
1747   }
1748   }
1749   return false;
1750 }
1751 
1752 /// Emit a store/load combination to the stack.  This stores
1753 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1754 /// a load from the stack slot to DestVT, extending it if needed.
1755 /// The resultant code need not be legal.
1756 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1757                                                EVT DestVT, const SDLoc &dl) {
1758   return EmitStackConvert(SrcOp, SlotVT, DestVT, dl, DAG.getEntryNode());
1759 }
1760 
1761 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1762                                                EVT DestVT, const SDLoc &dl,
1763                                                SDValue Chain) {
1764   // Create the stack frame object.
1765   unsigned SrcAlign = DAG.getDataLayout().getPrefTypeAlignment(
1766       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1767   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
1768 
1769   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1770   int SPFI = StackPtrFI->getIndex();
1771   MachinePointerInfo PtrInfo =
1772       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1773 
1774   unsigned SrcSize = SrcOp.getValueSizeInBits();
1775   unsigned SlotSize = SlotVT.getSizeInBits();
1776   unsigned DestSize = DestVT.getSizeInBits();
1777   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1778   unsigned DestAlign = DAG.getDataLayout().getPrefTypeAlignment(DestType);
1779 
1780   // Emit a store to the stack slot.  Use a truncstore if the input value is
1781   // later than DestVT.
1782   SDValue Store;
1783 
1784   if (SrcSize > SlotSize)
1785     Store = DAG.getTruncStore(Chain, dl, SrcOp, FIPtr, PtrInfo,
1786                               SlotVT, SrcAlign);
1787   else {
1788     assert(SrcSize == SlotSize && "Invalid store");
1789     Store =
1790         DAG.getStore(Chain, dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1791   }
1792 
1793   // Result is a load from the stack slot.
1794   if (SlotSize == DestSize)
1795     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1796 
1797   assert(SlotSize < DestSize && "Unknown extension!");
1798   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1799                         DestAlign);
1800 }
1801 
1802 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1803   SDLoc dl(Node);
1804   // Create a vector sized/aligned stack slot, store the value to element #0,
1805   // then load the whole vector back out.
1806   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1807 
1808   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1809   int SPFI = StackPtrFI->getIndex();
1810 
1811   SDValue Ch = DAG.getTruncStore(
1812       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1813       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1814       Node->getValueType(0).getVectorElementType());
1815   return DAG.getLoad(
1816       Node->getValueType(0), dl, Ch, StackPtr,
1817       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1818 }
1819 
1820 static bool
1821 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1822                      const TargetLowering &TLI, SDValue &Res) {
1823   unsigned NumElems = Node->getNumOperands();
1824   SDLoc dl(Node);
1825   EVT VT = Node->getValueType(0);
1826 
1827   // Try to group the scalars into pairs, shuffle the pairs together, then
1828   // shuffle the pairs of pairs together, etc. until the vector has
1829   // been built. This will work only if all of the necessary shuffle masks
1830   // are legal.
1831 
1832   // We do this in two phases; first to check the legality of the shuffles,
1833   // and next, assuming that all shuffles are legal, to create the new nodes.
1834   for (int Phase = 0; Phase < 2; ++Phase) {
1835     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1836                                                               NewIntermedVals;
1837     for (unsigned i = 0; i < NumElems; ++i) {
1838       SDValue V = Node->getOperand(i);
1839       if (V.isUndef())
1840         continue;
1841 
1842       SDValue Vec;
1843       if (Phase)
1844         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1845       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1846     }
1847 
1848     while (IntermedVals.size() > 2) {
1849       NewIntermedVals.clear();
1850       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1851         // This vector and the next vector are shuffled together (simply to
1852         // append the one to the other).
1853         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1854 
1855         SmallVector<int, 16> FinalIndices;
1856         FinalIndices.reserve(IntermedVals[i].second.size() +
1857                              IntermedVals[i+1].second.size());
1858 
1859         int k = 0;
1860         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1861              ++j, ++k) {
1862           ShuffleVec[k] = j;
1863           FinalIndices.push_back(IntermedVals[i].second[j]);
1864         }
1865         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1866              ++j, ++k) {
1867           ShuffleVec[k] = NumElems + j;
1868           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1869         }
1870 
1871         SDValue Shuffle;
1872         if (Phase)
1873           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1874                                          IntermedVals[i+1].first,
1875                                          ShuffleVec);
1876         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1877           return false;
1878         NewIntermedVals.push_back(
1879             std::make_pair(Shuffle, std::move(FinalIndices)));
1880       }
1881 
1882       // If we had an odd number of defined values, then append the last
1883       // element to the array of new vectors.
1884       if ((IntermedVals.size() & 1) != 0)
1885         NewIntermedVals.push_back(IntermedVals.back());
1886 
1887       IntermedVals.swap(NewIntermedVals);
1888     }
1889 
1890     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1891            "Invalid number of intermediate vectors");
1892     SDValue Vec1 = IntermedVals[0].first;
1893     SDValue Vec2;
1894     if (IntermedVals.size() > 1)
1895       Vec2 = IntermedVals[1].first;
1896     else if (Phase)
1897       Vec2 = DAG.getUNDEF(VT);
1898 
1899     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1900     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1901       ShuffleVec[IntermedVals[0].second[i]] = i;
1902     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1903       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1904 
1905     if (Phase)
1906       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1907     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1908       return false;
1909   }
1910 
1911   return true;
1912 }
1913 
1914 /// Expand a BUILD_VECTOR node on targets that don't
1915 /// support the operation, but do support the resultant vector type.
1916 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1917   unsigned NumElems = Node->getNumOperands();
1918   SDValue Value1, Value2;
1919   SDLoc dl(Node);
1920   EVT VT = Node->getValueType(0);
1921   EVT OpVT = Node->getOperand(0).getValueType();
1922   EVT EltVT = VT.getVectorElementType();
1923 
1924   // If the only non-undef value is the low element, turn this into a
1925   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1926   bool isOnlyLowElement = true;
1927   bool MoreThanTwoValues = false;
1928   bool isConstant = true;
1929   for (unsigned i = 0; i < NumElems; ++i) {
1930     SDValue V = Node->getOperand(i);
1931     if (V.isUndef())
1932       continue;
1933     if (i > 0)
1934       isOnlyLowElement = false;
1935     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1936       isConstant = false;
1937 
1938     if (!Value1.getNode()) {
1939       Value1 = V;
1940     } else if (!Value2.getNode()) {
1941       if (V != Value1)
1942         Value2 = V;
1943     } else if (V != Value1 && V != Value2) {
1944       MoreThanTwoValues = true;
1945     }
1946   }
1947 
1948   if (!Value1.getNode())
1949     return DAG.getUNDEF(VT);
1950 
1951   if (isOnlyLowElement)
1952     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1953 
1954   // If all elements are constants, create a load from the constant pool.
1955   if (isConstant) {
1956     SmallVector<Constant*, 16> CV;
1957     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1958       if (ConstantFPSDNode *V =
1959           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1960         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1961       } else if (ConstantSDNode *V =
1962                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1963         if (OpVT==EltVT)
1964           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1965         else {
1966           // If OpVT and EltVT don't match, EltVT is not legal and the
1967           // element values have been promoted/truncated earlier.  Undo this;
1968           // we don't want a v16i8 to become a v16i32 for example.
1969           const ConstantInt *CI = V->getConstantIntValue();
1970           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1971                                         CI->getZExtValue()));
1972         }
1973       } else {
1974         assert(Node->getOperand(i).isUndef());
1975         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1976         CV.push_back(UndefValue::get(OpNTy));
1977       }
1978     }
1979     Constant *CP = ConstantVector::get(CV);
1980     SDValue CPIdx =
1981         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1982     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
1983     return DAG.getLoad(
1984         VT, dl, DAG.getEntryNode(), CPIdx,
1985         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1986         Alignment);
1987   }
1988 
1989   SmallSet<SDValue, 16> DefinedValues;
1990   for (unsigned i = 0; i < NumElems; ++i) {
1991     if (Node->getOperand(i).isUndef())
1992       continue;
1993     DefinedValues.insert(Node->getOperand(i));
1994   }
1995 
1996   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1997     if (!MoreThanTwoValues) {
1998       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1999       for (unsigned i = 0; i < NumElems; ++i) {
2000         SDValue V = Node->getOperand(i);
2001         if (V.isUndef())
2002           continue;
2003         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
2004       }
2005       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
2006         // Get the splatted value into the low element of a vector register.
2007         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
2008         SDValue Vec2;
2009         if (Value2.getNode())
2010           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
2011         else
2012           Vec2 = DAG.getUNDEF(VT);
2013 
2014         // Return shuffle(LowValVec, undef, <0,0,0,0>)
2015         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
2016       }
2017     } else {
2018       SDValue Res;
2019       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
2020         return Res;
2021     }
2022   }
2023 
2024   // Otherwise, we can't handle this case efficiently.
2025   return ExpandVectorBuildThroughStack(Node);
2026 }
2027 
2028 // Expand a node into a call to a libcall.  If the result value
2029 // does not fit into a register, return the lo part and set the hi part to the
2030 // by-reg argument.  If it does fit into a single register, return the result
2031 // and leave the Hi part unset.
2032 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
2033                                             bool isSigned) {
2034   TargetLowering::ArgListTy Args;
2035   TargetLowering::ArgListEntry Entry;
2036   for (const SDValue &Op : Node->op_values()) {
2037     EVT ArgVT = Op.getValueType();
2038     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2039     Entry.Node = Op;
2040     Entry.Ty = ArgTy;
2041     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2042     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2043     Args.push_back(Entry);
2044   }
2045   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2046                                          TLI.getPointerTy(DAG.getDataLayout()));
2047 
2048   EVT RetVT = Node->getValueType(0);
2049   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2050 
2051   // By default, the input chain to this libcall is the entry node of the
2052   // function. If the libcall is going to be emitted as a tail call then
2053   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2054   // node which is being folded has a non-entry input chain.
2055   SDValue InChain = DAG.getEntryNode();
2056 
2057   // isTailCall may be true since the callee does not reference caller stack
2058   // frame. Check if it's in the right position and that the return types match.
2059   SDValue TCChain = InChain;
2060   const Function &F = DAG.getMachineFunction().getFunction();
2061   bool isTailCall =
2062       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2063       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2064   if (isTailCall)
2065     InChain = TCChain;
2066 
2067   TargetLowering::CallLoweringInfo CLI(DAG);
2068   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2069   CLI.setDebugLoc(SDLoc(Node))
2070       .setChain(InChain)
2071       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2072                     std::move(Args))
2073       .setTailCall(isTailCall)
2074       .setSExtResult(signExtend)
2075       .setZExtResult(!signExtend)
2076       .setIsPostTypeLegalization(true);
2077 
2078   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2079 
2080   if (!CallInfo.second.getNode()) {
2081     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump());
2082     // It's a tailcall, return the chain (which is the DAG root).
2083     return DAG.getRoot();
2084   }
2085 
2086   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump());
2087   return CallInfo.first;
2088 }
2089 
2090 // Expand a node into a call to a libcall. Similar to
2091 // ExpandLibCall except that the first operand is the in-chain.
2092 std::pair<SDValue, SDValue>
2093 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
2094                                          SDNode *Node,
2095                                          bool isSigned) {
2096   SDValue InChain = Node->getOperand(0);
2097 
2098   TargetLowering::ArgListTy Args;
2099   TargetLowering::ArgListEntry Entry;
2100   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
2101     EVT ArgVT = Node->getOperand(i).getValueType();
2102     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2103     Entry.Node = Node->getOperand(i);
2104     Entry.Ty = ArgTy;
2105     Entry.IsSExt = isSigned;
2106     Entry.IsZExt = !isSigned;
2107     Args.push_back(Entry);
2108   }
2109   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2110                                          TLI.getPointerTy(DAG.getDataLayout()));
2111 
2112   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
2113 
2114   TargetLowering::CallLoweringInfo CLI(DAG);
2115   CLI.setDebugLoc(SDLoc(Node))
2116       .setChain(InChain)
2117       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2118                     std::move(Args))
2119       .setSExtResult(isSigned)
2120       .setZExtResult(!isSigned);
2121 
2122   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2123 
2124   return CallInfo;
2125 }
2126 
2127 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2128                                               RTLIB::Libcall Call_F32,
2129                                               RTLIB::Libcall Call_F64,
2130                                               RTLIB::Libcall Call_F80,
2131                                               RTLIB::Libcall Call_F128,
2132                                               RTLIB::Libcall Call_PPCF128) {
2133   if (Node->isStrictFPOpcode())
2134     Node = DAG.mutateStrictFPToFP(Node);
2135 
2136   RTLIB::Libcall LC;
2137   switch (Node->getSimpleValueType(0).SimpleTy) {
2138   default: llvm_unreachable("Unexpected request for libcall!");
2139   case MVT::f32: LC = Call_F32; break;
2140   case MVT::f64: LC = Call_F64; break;
2141   case MVT::f80: LC = Call_F80; break;
2142   case MVT::f128: LC = Call_F128; break;
2143   case MVT::ppcf128: LC = Call_PPCF128; break;
2144   }
2145   return ExpandLibCall(LC, Node, false);
2146 }
2147 
2148 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2149                                                RTLIB::Libcall Call_I8,
2150                                                RTLIB::Libcall Call_I16,
2151                                                RTLIB::Libcall Call_I32,
2152                                                RTLIB::Libcall Call_I64,
2153                                                RTLIB::Libcall Call_I128) {
2154   RTLIB::Libcall LC;
2155   switch (Node->getSimpleValueType(0).SimpleTy) {
2156   default: llvm_unreachable("Unexpected request for libcall!");
2157   case MVT::i8:   LC = Call_I8; break;
2158   case MVT::i16:  LC = Call_I16; break;
2159   case MVT::i32:  LC = Call_I32; break;
2160   case MVT::i64:  LC = Call_I64; break;
2161   case MVT::i128: LC = Call_I128; break;
2162   }
2163   return ExpandLibCall(LC, Node, isSigned);
2164 }
2165 
2166 /// Expand the node to a libcall based on first argument type (for instance
2167 /// lround and its variant).
2168 SDValue SelectionDAGLegalize::ExpandArgFPLibCall(SDNode* Node,
2169                                                  RTLIB::Libcall Call_F32,
2170                                                  RTLIB::Libcall Call_F64,
2171                                                  RTLIB::Libcall Call_F80,
2172                                                  RTLIB::Libcall Call_F128,
2173                                                  RTLIB::Libcall Call_PPCF128) {
2174   RTLIB::Libcall LC;
2175   switch (Node->getOperand(0).getValueType().getSimpleVT().SimpleTy) {
2176   default: llvm_unreachable("Unexpected request for libcall!");
2177   case MVT::f32:     LC = Call_F32; break;
2178   case MVT::f64:     LC = Call_F64; break;
2179   case MVT::f80:     LC = Call_F80; break;
2180   case MVT::f128:    LC = Call_F128; break;
2181   case MVT::ppcf128: LC = Call_PPCF128; break;
2182   }
2183 
2184   return ExpandLibCall(LC, Node, false);
2185 }
2186 
2187 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2188 void
2189 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2190                                           SmallVectorImpl<SDValue> &Results) {
2191   unsigned Opcode = Node->getOpcode();
2192   bool isSigned = Opcode == ISD::SDIVREM;
2193 
2194   RTLIB::Libcall LC;
2195   switch (Node->getSimpleValueType(0).SimpleTy) {
2196   default: llvm_unreachable("Unexpected request for libcall!");
2197   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2198   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2199   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2200   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2201   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2202   }
2203 
2204   // The input chain to this libcall is the entry node of the function.
2205   // Legalizing the call will automatically add the previous call to the
2206   // dependence.
2207   SDValue InChain = DAG.getEntryNode();
2208 
2209   EVT RetVT = Node->getValueType(0);
2210   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2211 
2212   TargetLowering::ArgListTy Args;
2213   TargetLowering::ArgListEntry Entry;
2214   for (const SDValue &Op : Node->op_values()) {
2215     EVT ArgVT = Op.getValueType();
2216     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2217     Entry.Node = Op;
2218     Entry.Ty = ArgTy;
2219     Entry.IsSExt = isSigned;
2220     Entry.IsZExt = !isSigned;
2221     Args.push_back(Entry);
2222   }
2223 
2224   // Also pass the return address of the remainder.
2225   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2226   Entry.Node = FIPtr;
2227   Entry.Ty = RetTy->getPointerTo();
2228   Entry.IsSExt = isSigned;
2229   Entry.IsZExt = !isSigned;
2230   Args.push_back(Entry);
2231 
2232   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2233                                          TLI.getPointerTy(DAG.getDataLayout()));
2234 
2235   SDLoc dl(Node);
2236   TargetLowering::CallLoweringInfo CLI(DAG);
2237   CLI.setDebugLoc(dl)
2238       .setChain(InChain)
2239       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2240                     std::move(Args))
2241       .setSExtResult(isSigned)
2242       .setZExtResult(!isSigned);
2243 
2244   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2245 
2246   // Remainder is loaded back from the stack frame.
2247   SDValue Rem =
2248       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2249   Results.push_back(CallInfo.first);
2250   Results.push_back(Rem);
2251 }
2252 
2253 /// Return true if sincos libcall is available.
2254 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2255   RTLIB::Libcall LC;
2256   switch (Node->getSimpleValueType(0).SimpleTy) {
2257   default: llvm_unreachable("Unexpected request for libcall!");
2258   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2259   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2260   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2261   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2262   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2263   }
2264   return TLI.getLibcallName(LC) != nullptr;
2265 }
2266 
2267 /// Only issue sincos libcall if both sin and cos are needed.
2268 static bool useSinCos(SDNode *Node) {
2269   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2270     ? ISD::FCOS : ISD::FSIN;
2271 
2272   SDValue Op0 = Node->getOperand(0);
2273   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2274        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2275     SDNode *User = *UI;
2276     if (User == Node)
2277       continue;
2278     // The other user might have been turned into sincos already.
2279     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2280       return true;
2281   }
2282   return false;
2283 }
2284 
2285 /// Issue libcalls to sincos to compute sin / cos pairs.
2286 void
2287 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2288                                           SmallVectorImpl<SDValue> &Results) {
2289   RTLIB::Libcall LC;
2290   switch (Node->getSimpleValueType(0).SimpleTy) {
2291   default: llvm_unreachable("Unexpected request for libcall!");
2292   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2293   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2294   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2295   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2296   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2297   }
2298 
2299   // The input chain to this libcall is the entry node of the function.
2300   // Legalizing the call will automatically add the previous call to the
2301   // dependence.
2302   SDValue InChain = DAG.getEntryNode();
2303 
2304   EVT RetVT = Node->getValueType(0);
2305   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2306 
2307   TargetLowering::ArgListTy Args;
2308   TargetLowering::ArgListEntry Entry;
2309 
2310   // Pass the argument.
2311   Entry.Node = Node->getOperand(0);
2312   Entry.Ty = RetTy;
2313   Entry.IsSExt = false;
2314   Entry.IsZExt = false;
2315   Args.push_back(Entry);
2316 
2317   // Pass the return address of sin.
2318   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2319   Entry.Node = SinPtr;
2320   Entry.Ty = RetTy->getPointerTo();
2321   Entry.IsSExt = false;
2322   Entry.IsZExt = false;
2323   Args.push_back(Entry);
2324 
2325   // Also pass the return address of the cos.
2326   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2327   Entry.Node = CosPtr;
2328   Entry.Ty = RetTy->getPointerTo();
2329   Entry.IsSExt = false;
2330   Entry.IsZExt = false;
2331   Args.push_back(Entry);
2332 
2333   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2334                                          TLI.getPointerTy(DAG.getDataLayout()));
2335 
2336   SDLoc dl(Node);
2337   TargetLowering::CallLoweringInfo CLI(DAG);
2338   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2339       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2340       std::move(Args));
2341 
2342   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2343 
2344   Results.push_back(
2345       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2346   Results.push_back(
2347       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2348 }
2349 
2350 /// This function is responsible for legalizing a
2351 /// INT_TO_FP operation of the specified operand when the target requests that
2352 /// we expand it.  At this point, we know that the result and operand types are
2353 /// legal for the target.
2354 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0,
2355                                                    EVT DestVT,
2356                                                    const SDLoc &dl) {
2357   EVT SrcVT = Op0.getValueType();
2358 
2359   // TODO: Should any fast-math-flags be set for the created nodes?
2360   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2361   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2362     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2363                          "expansion\n");
2364 
2365     // Get the stack frame index of a 8 byte buffer.
2366     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2367 
2368     // word offset constant for Hi/Lo address computation
2369     SDValue WordOff = DAG.getConstant(sizeof(int), dl,
2370                                       StackSlot.getValueType());
2371     // set up Hi and Lo (into buffer) address based on endian
2372     SDValue Hi = StackSlot;
2373     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
2374                              StackSlot, WordOff);
2375     if (DAG.getDataLayout().isLittleEndian())
2376       std::swap(Hi, Lo);
2377 
2378     // if signed map to unsigned space
2379     SDValue Op0Mapped;
2380     if (isSigned) {
2381       // constant used to invert sign bit (signed to unsigned mapping)
2382       SDValue SignBit = DAG.getConstant(0x80000000u, dl, MVT::i32);
2383       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
2384     } else {
2385       Op0Mapped = Op0;
2386     }
2387     // store the lo of the constructed double - based on integer input
2388     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl, Op0Mapped, Lo,
2389                                   MachinePointerInfo());
2390     // initial hi portion of constructed double
2391     SDValue InitialHi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2392     // store the hi of the constructed double - biased exponent
2393     SDValue Store2 =
2394         DAG.getStore(Store1, dl, InitialHi, Hi, MachinePointerInfo());
2395     // load the constructed double
2396     SDValue Load =
2397         DAG.getLoad(MVT::f64, dl, Store2, StackSlot, MachinePointerInfo());
2398     // FP constant to bias correct the final result
2399     SDValue Bias = DAG.getConstantFP(isSigned ?
2400                                      BitsToDouble(0x4330000080000000ULL) :
2401                                      BitsToDouble(0x4330000000000000ULL),
2402                                      dl, MVT::f64);
2403     // subtract the bias
2404     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2405     // final result
2406     SDValue Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2407     return Result;
2408   }
2409   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2410   // Code below here assumes !isSigned without checking again.
2411 
2412   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2413 
2414   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2415                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2416   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2417           Four = DAG.getIntPtrConstant(4, dl);
2418   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2419                                     SignSet, Four, Zero);
2420 
2421   // If the sign bit of the integer is set, the large number will be treated
2422   // as a negative number.  To counteract this, the dynamic code adds an
2423   // offset depending on the data type.
2424   uint64_t FF;
2425   switch (SrcVT.getSimpleVT().SimpleTy) {
2426   default: llvm_unreachable("Unsupported integer type!");
2427   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2428   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2429   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2430   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2431   }
2432   if (DAG.getDataLayout().isLittleEndian())
2433     FF <<= 32;
2434   Constant *FudgeFactor = ConstantInt::get(
2435                                        Type::getInt64Ty(*DAG.getContext()), FF);
2436 
2437   SDValue CPIdx =
2438       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2439   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
2440   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2441   Alignment = std::min(Alignment, 4u);
2442   SDValue FudgeInReg;
2443   if (DestVT == MVT::f32)
2444     FudgeInReg = DAG.getLoad(
2445         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2446         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2447         Alignment);
2448   else {
2449     SDValue Load = DAG.getExtLoad(
2450         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2451         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2452         Alignment);
2453     HandleSDNode Handle(Load);
2454     LegalizeOp(Load.getNode());
2455     FudgeInReg = Handle.getValue();
2456   }
2457 
2458   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2459 }
2460 
2461 /// This function is responsible for legalizing a
2462 /// *INT_TO_FP operation of the specified operand when the target requests that
2463 /// we promote it.  At this point, we know that the result and operand types are
2464 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2465 /// operation that takes a larger input.
2466 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT,
2467                                                     bool isSigned,
2468                                                     const SDLoc &dl) {
2469   // First step, figure out the appropriate *INT_TO_FP operation to use.
2470   EVT NewInTy = LegalOp.getValueType();
2471 
2472   unsigned OpToUse = 0;
2473 
2474   // Scan for the appropriate larger type to use.
2475   while (true) {
2476     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2477     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2478 
2479     // If the target supports SINT_TO_FP of this type, use it.
2480     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
2481       OpToUse = ISD::SINT_TO_FP;
2482       break;
2483     }
2484     if (isSigned) continue;
2485 
2486     // If the target supports UINT_TO_FP of this type, use it.
2487     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
2488       OpToUse = ISD::UINT_TO_FP;
2489       break;
2490     }
2491 
2492     // Otherwise, try a larger type.
2493   }
2494 
2495   // Okay, we found the operation and type to use.  Zero extend our input to the
2496   // desired type then run the operation on it.
2497   return DAG.getNode(OpToUse, dl, DestVT,
2498                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2499                                  dl, NewInTy, LegalOp));
2500 }
2501 
2502 /// This function is responsible for legalizing a
2503 /// FP_TO_*INT operation of the specified operand when the target requests that
2504 /// we promote it.  At this point, we know that the result and operand types are
2505 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2506 /// operation that returns a larger result.
2507 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT,
2508                                                     bool isSigned,
2509                                                     const SDLoc &dl) {
2510   // First step, figure out the appropriate FP_TO*INT operation to use.
2511   EVT NewOutTy = DestVT;
2512 
2513   unsigned OpToUse = 0;
2514 
2515   // Scan for the appropriate larger type to use.
2516   while (true) {
2517     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2518     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2519 
2520     // A larger signed type can hold all unsigned values of the requested type,
2521     // so using FP_TO_SINT is valid
2522     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
2523       OpToUse = ISD::FP_TO_SINT;
2524       break;
2525     }
2526 
2527     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2528     if (!isSigned && TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
2529       OpToUse = ISD::FP_TO_UINT;
2530       break;
2531     }
2532 
2533     // Otherwise, try a larger type.
2534   }
2535 
2536   // Okay, we found the operation and type to use.
2537   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2538 
2539   // Truncate the result of the extended FP_TO_*INT operation to the desired
2540   // size.
2541   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2542 }
2543 
2544 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
2545 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2546   EVT VT = Op.getValueType();
2547   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2548   unsigned Sz = VT.getScalarSizeInBits();
2549 
2550   SDValue Tmp, Tmp2, Tmp3;
2551 
2552   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2553   // and finally the i1 pairs.
2554   // TODO: We can easily support i4/i2 legal types if any target ever does.
2555   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2556     // Create the masks - repeating the pattern every byte.
2557     APInt MaskHi4 = APInt::getSplat(Sz, APInt(8, 0xF0));
2558     APInt MaskHi2 = APInt::getSplat(Sz, APInt(8, 0xCC));
2559     APInt MaskHi1 = APInt::getSplat(Sz, APInt(8, 0xAA));
2560     APInt MaskLo4 = APInt::getSplat(Sz, APInt(8, 0x0F));
2561     APInt MaskLo2 = APInt::getSplat(Sz, APInt(8, 0x33));
2562     APInt MaskLo1 = APInt::getSplat(Sz, APInt(8, 0x55));
2563 
2564     // BSWAP if the type is wider than a single byte.
2565     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2566 
2567     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2568     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2569     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2570     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, SHVT));
2571     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, SHVT));
2572     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2573 
2574     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2575     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2576     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2577     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, SHVT));
2578     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, SHVT));
2579     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2580 
2581     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2582     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2583     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2584     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, SHVT));
2585     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, SHVT));
2586     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2587     return Tmp;
2588   }
2589 
2590   Tmp = DAG.getConstant(0, dl, VT);
2591   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2592     if (I < J)
2593       Tmp2 =
2594           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2595     else
2596       Tmp2 =
2597           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2598 
2599     APInt Shift(Sz, 1);
2600     Shift <<= J;
2601     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2602     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2603   }
2604 
2605   return Tmp;
2606 }
2607 
2608 /// Open code the operations for BSWAP of the specified operation.
2609 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2610   EVT VT = Op.getValueType();
2611   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2612   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2613   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2614   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2615   case MVT::i16:
2616     // Use a rotate by 8. This can be further expanded if necessary.
2617     return DAG.getNode(ISD::ROTL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2618   case MVT::i32:
2619     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2620     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2621     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2622     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2623     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2624                        DAG.getConstant(0xFF0000, dl, VT));
2625     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2626     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2627     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2628     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2629   case MVT::i64:
2630     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2631     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2632     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2633     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2634     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2635     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2636     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2637     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2638     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2639                        DAG.getConstant(255ULL<<48, dl, VT));
2640     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2641                        DAG.getConstant(255ULL<<40, dl, VT));
2642     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2643                        DAG.getConstant(255ULL<<32, dl, VT));
2644     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2645                        DAG.getConstant(255ULL<<24, dl, VT));
2646     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2647                        DAG.getConstant(255ULL<<16, dl, VT));
2648     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2649                        DAG.getConstant(255ULL<<8 , dl, VT));
2650     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2651     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2652     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2653     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2654     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2655     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2656     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2657   }
2658 }
2659 
2660 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2661   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2662   SmallVector<SDValue, 8> Results;
2663   SDLoc dl(Node);
2664   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2665   bool NeedInvert;
2666   switch (Node->getOpcode()) {
2667   case ISD::ABS:
2668     if (TLI.expandABS(Node, Tmp1, DAG))
2669       Results.push_back(Tmp1);
2670     break;
2671   case ISD::CTPOP:
2672     if (TLI.expandCTPOP(Node, Tmp1, DAG))
2673       Results.push_back(Tmp1);
2674     break;
2675   case ISD::CTLZ:
2676   case ISD::CTLZ_ZERO_UNDEF:
2677     if (TLI.expandCTLZ(Node, Tmp1, DAG))
2678       Results.push_back(Tmp1);
2679     break;
2680   case ISD::CTTZ:
2681   case ISD::CTTZ_ZERO_UNDEF:
2682     if (TLI.expandCTTZ(Node, Tmp1, DAG))
2683       Results.push_back(Tmp1);
2684     break;
2685   case ISD::BITREVERSE:
2686     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2687     break;
2688   case ISD::BSWAP:
2689     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2690     break;
2691   case ISD::FRAMEADDR:
2692   case ISD::RETURNADDR:
2693   case ISD::FRAME_TO_ARGS_OFFSET:
2694     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2695     break;
2696   case ISD::EH_DWARF_CFA: {
2697     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2698                                         TLI.getPointerTy(DAG.getDataLayout()));
2699     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2700                                  CfaArg.getValueType(),
2701                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2702                                              CfaArg.getValueType()),
2703                                  CfaArg);
2704     SDValue FA = DAG.getNode(
2705         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2706         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2707     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2708                                   FA, Offset));
2709     break;
2710   }
2711   case ISD::FLT_ROUNDS_:
2712     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2713     break;
2714   case ISD::EH_RETURN:
2715   case ISD::EH_LABEL:
2716   case ISD::PREFETCH:
2717   case ISD::VAEND:
2718   case ISD::EH_SJLJ_LONGJMP:
2719     // If the target didn't expand these, there's nothing to do, so just
2720     // preserve the chain and be done.
2721     Results.push_back(Node->getOperand(0));
2722     break;
2723   case ISD::READCYCLECOUNTER:
2724     // If the target didn't expand this, just return 'zero' and preserve the
2725     // chain.
2726     Results.append(Node->getNumValues() - 1,
2727                    DAG.getConstant(0, dl, Node->getValueType(0)));
2728     Results.push_back(Node->getOperand(0));
2729     break;
2730   case ISD::EH_SJLJ_SETJMP:
2731     // If the target didn't expand this, just return 'zero' and preserve the
2732     // chain.
2733     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2734     Results.push_back(Node->getOperand(0));
2735     break;
2736   case ISD::ATOMIC_LOAD: {
2737     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2738     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2739     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2740     SDValue Swap = DAG.getAtomicCmpSwap(
2741         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2742         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2743         cast<AtomicSDNode>(Node)->getMemOperand());
2744     Results.push_back(Swap.getValue(0));
2745     Results.push_back(Swap.getValue(1));
2746     break;
2747   }
2748   case ISD::ATOMIC_STORE: {
2749     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2750     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2751                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2752                                  Node->getOperand(0),
2753                                  Node->getOperand(1), Node->getOperand(2),
2754                                  cast<AtomicSDNode>(Node)->getMemOperand());
2755     Results.push_back(Swap.getValue(1));
2756     break;
2757   }
2758   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2759     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2760     // splits out the success value as a comparison. Expanding the resulting
2761     // ATOMIC_CMP_SWAP will produce a libcall.
2762     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2763     SDValue Res = DAG.getAtomicCmpSwap(
2764         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2765         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2766         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2767 
2768     SDValue ExtRes = Res;
2769     SDValue LHS = Res;
2770     SDValue RHS = Node->getOperand(1);
2771 
2772     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2773     EVT OuterType = Node->getValueType(0);
2774     switch (TLI.getExtendForAtomicOps()) {
2775     case ISD::SIGN_EXTEND:
2776       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2777                         DAG.getValueType(AtomicType));
2778       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2779                         Node->getOperand(2), DAG.getValueType(AtomicType));
2780       ExtRes = LHS;
2781       break;
2782     case ISD::ZERO_EXTEND:
2783       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2784                         DAG.getValueType(AtomicType));
2785       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2786       ExtRes = LHS;
2787       break;
2788     case ISD::ANY_EXTEND:
2789       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2790       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2791       break;
2792     default:
2793       llvm_unreachable("Invalid atomic op extension");
2794     }
2795 
2796     SDValue Success =
2797         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2798 
2799     Results.push_back(ExtRes.getValue(0));
2800     Results.push_back(Success);
2801     Results.push_back(Res.getValue(1));
2802     break;
2803   }
2804   case ISD::DYNAMIC_STACKALLOC:
2805     ExpandDYNAMIC_STACKALLOC(Node, Results);
2806     break;
2807   case ISD::MERGE_VALUES:
2808     for (unsigned i = 0; i < Node->getNumValues(); i++)
2809       Results.push_back(Node->getOperand(i));
2810     break;
2811   case ISD::UNDEF: {
2812     EVT VT = Node->getValueType(0);
2813     if (VT.isInteger())
2814       Results.push_back(DAG.getConstant(0, dl, VT));
2815     else {
2816       assert(VT.isFloatingPoint() && "Unknown value type!");
2817       Results.push_back(DAG.getConstantFP(0, dl, VT));
2818     }
2819     break;
2820   }
2821   case ISD::STRICT_FP_ROUND:
2822     Tmp1 = EmitStackConvert(Node->getOperand(1),
2823                             Node->getValueType(0),
2824                             Node->getValueType(0), dl, Node->getOperand(0));
2825     ReplaceNode(Node, Tmp1.getNode());
2826     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_ROUND node\n");
2827     return true;
2828   case ISD::FP_ROUND:
2829   case ISD::BITCAST:
2830     Tmp1 = EmitStackConvert(Node->getOperand(0),
2831                             Node->getValueType(0),
2832                             Node->getValueType(0), dl);
2833     Results.push_back(Tmp1);
2834     break;
2835   case ISD::STRICT_FP_EXTEND:
2836     Tmp1 = EmitStackConvert(Node->getOperand(1),
2837                             Node->getOperand(1).getValueType(),
2838                             Node->getValueType(0), dl, Node->getOperand(0));
2839     ReplaceNode(Node, Tmp1.getNode());
2840     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_EXTEND node\n");
2841     return true;
2842   case ISD::FP_EXTEND:
2843     Tmp1 = EmitStackConvert(Node->getOperand(0),
2844                             Node->getOperand(0).getValueType(),
2845                             Node->getValueType(0), dl);
2846     Results.push_back(Tmp1);
2847     break;
2848   case ISD::SIGN_EXTEND_INREG: {
2849     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2850     EVT VT = Node->getValueType(0);
2851 
2852     // An in-register sign-extend of a boolean is a negation:
2853     // 'true' (1) sign-extended is -1.
2854     // 'false' (0) sign-extended is 0.
2855     // However, we must mask the high bits of the source operand because the
2856     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
2857 
2858     // TODO: Do this for vectors too?
2859     if (ExtraVT.getSizeInBits() == 1) {
2860       SDValue One = DAG.getConstant(1, dl, VT);
2861       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
2862       SDValue Zero = DAG.getConstant(0, dl, VT);
2863       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
2864       Results.push_back(Neg);
2865       break;
2866     }
2867 
2868     // NOTE: we could fall back on load/store here too for targets without
2869     // SRA.  However, it is doubtful that any exist.
2870     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2871     unsigned BitsDiff = VT.getScalarSizeInBits() -
2872                         ExtraVT.getScalarSizeInBits();
2873     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
2874     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
2875                        Node->getOperand(0), ShiftCst);
2876     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
2877     Results.push_back(Tmp1);
2878     break;
2879   }
2880   case ISD::FP_ROUND_INREG: {
2881     // The only way we can lower this is to turn it into a TRUNCSTORE,
2882     // EXTLOAD pair, targeting a temporary location (a stack slot).
2883 
2884     // NOTE: there is a choice here between constantly creating new stack
2885     // slots and always reusing the same one.  We currently always create
2886     // new ones, as reuse may inhibit scheduling.
2887     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2888     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
2889                             Node->getValueType(0), dl);
2890     Results.push_back(Tmp1);
2891     break;
2892   }
2893   case ISD::UINT_TO_FP:
2894     if (TLI.expandUINT_TO_FP(Node, Tmp1, DAG)) {
2895       Results.push_back(Tmp1);
2896       break;
2897     }
2898     LLVM_FALLTHROUGH;
2899   case ISD::SINT_TO_FP:
2900     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
2901                                 Node->getOperand(0), Node->getValueType(0), dl);
2902     Results.push_back(Tmp1);
2903     break;
2904   case ISD::FP_TO_SINT:
2905     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
2906       Results.push_back(Tmp1);
2907     break;
2908   case ISD::FP_TO_UINT:
2909     if (TLI.expandFP_TO_UINT(Node, Tmp1, DAG))
2910       Results.push_back(Tmp1);
2911     break;
2912   case ISD::LROUND:
2913     Results.push_back(ExpandArgFPLibCall(Node, RTLIB::LROUND_F32,
2914                                          RTLIB::LROUND_F64, RTLIB::LROUND_F80,
2915                                          RTLIB::LROUND_F128,
2916                                          RTLIB::LROUND_PPCF128));
2917     break;
2918   case ISD::LLROUND:
2919     Results.push_back(ExpandArgFPLibCall(Node, RTLIB::LLROUND_F32,
2920                                          RTLIB::LLROUND_F64, RTLIB::LLROUND_F80,
2921                                          RTLIB::LLROUND_F128,
2922                                          RTLIB::LLROUND_PPCF128));
2923     break;
2924   case ISD::LRINT:
2925     Results.push_back(ExpandArgFPLibCall(Node, RTLIB::LRINT_F32,
2926                                          RTLIB::LRINT_F64, RTLIB::LRINT_F80,
2927                                          RTLIB::LRINT_F128,
2928                                          RTLIB::LRINT_PPCF128));
2929     break;
2930   case ISD::LLRINT:
2931     Results.push_back(ExpandArgFPLibCall(Node, RTLIB::LLRINT_F32,
2932                                          RTLIB::LLRINT_F64, RTLIB::LLRINT_F80,
2933                                          RTLIB::LLRINT_F128,
2934                                          RTLIB::LLRINT_PPCF128));
2935     break;
2936   case ISD::VAARG:
2937     Results.push_back(DAG.expandVAArg(Node));
2938     Results.push_back(Results[0].getValue(1));
2939     break;
2940   case ISD::VACOPY:
2941     Results.push_back(DAG.expandVACopy(Node));
2942     break;
2943   case ISD::EXTRACT_VECTOR_ELT:
2944     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
2945       // This must be an access of the only element.  Return it.
2946       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
2947                          Node->getOperand(0));
2948     else
2949       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
2950     Results.push_back(Tmp1);
2951     break;
2952   case ISD::EXTRACT_SUBVECTOR:
2953     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
2954     break;
2955   case ISD::INSERT_SUBVECTOR:
2956     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
2957     break;
2958   case ISD::CONCAT_VECTORS:
2959     Results.push_back(ExpandVectorBuildThroughStack(Node));
2960     break;
2961   case ISD::SCALAR_TO_VECTOR:
2962     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
2963     break;
2964   case ISD::INSERT_VECTOR_ELT:
2965     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
2966                                               Node->getOperand(1),
2967                                               Node->getOperand(2), dl));
2968     break;
2969   case ISD::VECTOR_SHUFFLE: {
2970     SmallVector<int, 32> NewMask;
2971     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
2972 
2973     EVT VT = Node->getValueType(0);
2974     EVT EltVT = VT.getVectorElementType();
2975     SDValue Op0 = Node->getOperand(0);
2976     SDValue Op1 = Node->getOperand(1);
2977     if (!TLI.isTypeLegal(EltVT)) {
2978       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
2979 
2980       // BUILD_VECTOR operands are allowed to be wider than the element type.
2981       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
2982       // it.
2983       if (NewEltVT.bitsLT(EltVT)) {
2984         // Convert shuffle node.
2985         // If original node was v4i64 and the new EltVT is i32,
2986         // cast operands to v8i32 and re-build the mask.
2987 
2988         // Calculate new VT, the size of the new VT should be equal to original.
2989         EVT NewVT =
2990             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
2991                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
2992         assert(NewVT.bitsEq(VT));
2993 
2994         // cast operands to new VT
2995         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
2996         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
2997 
2998         // Convert the shuffle mask
2999         unsigned int factor =
3000                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3001 
3002         // EltVT gets smaller
3003         assert(factor > 0);
3004 
3005         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3006           if (Mask[i] < 0) {
3007             for (unsigned fi = 0; fi < factor; ++fi)
3008               NewMask.push_back(Mask[i]);
3009           }
3010           else {
3011             for (unsigned fi = 0; fi < factor; ++fi)
3012               NewMask.push_back(Mask[i]*factor+fi);
3013           }
3014         }
3015         Mask = NewMask;
3016         VT = NewVT;
3017       }
3018       EltVT = NewEltVT;
3019     }
3020     unsigned NumElems = VT.getVectorNumElements();
3021     SmallVector<SDValue, 16> Ops;
3022     for (unsigned i = 0; i != NumElems; ++i) {
3023       if (Mask[i] < 0) {
3024         Ops.push_back(DAG.getUNDEF(EltVT));
3025         continue;
3026       }
3027       unsigned Idx = Mask[i];
3028       if (Idx < NumElems)
3029         Ops.push_back(DAG.getNode(
3030             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3031             DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout()))));
3032       else
3033         Ops.push_back(DAG.getNode(
3034             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3035             DAG.getConstant(Idx - NumElems, dl,
3036                             TLI.getVectorIdxTy(DAG.getDataLayout()))));
3037     }
3038 
3039     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3040     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3041     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3042     Results.push_back(Tmp1);
3043     break;
3044   }
3045   case ISD::EXTRACT_ELEMENT: {
3046     EVT OpTy = Node->getOperand(0).getValueType();
3047     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3048       // 1 -> Hi
3049       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3050                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3051                                          TLI.getShiftAmountTy(
3052                                              Node->getOperand(0).getValueType(),
3053                                              DAG.getDataLayout())));
3054       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3055     } else {
3056       // 0 -> Lo
3057       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3058                          Node->getOperand(0));
3059     }
3060     Results.push_back(Tmp1);
3061     break;
3062   }
3063   case ISD::STACKSAVE:
3064     // Expand to CopyFromReg if the target set
3065     // StackPointerRegisterToSaveRestore.
3066     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3067       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3068                                            Node->getValueType(0)));
3069       Results.push_back(Results[0].getValue(1));
3070     } else {
3071       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3072       Results.push_back(Node->getOperand(0));
3073     }
3074     break;
3075   case ISD::STACKRESTORE:
3076     // Expand to CopyToReg if the target set
3077     // StackPointerRegisterToSaveRestore.
3078     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3079       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3080                                          Node->getOperand(1)));
3081     } else {
3082       Results.push_back(Node->getOperand(0));
3083     }
3084     break;
3085   case ISD::GET_DYNAMIC_AREA_OFFSET:
3086     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3087     Results.push_back(Results[0].getValue(0));
3088     break;
3089   case ISD::FCOPYSIGN:
3090     Results.push_back(ExpandFCOPYSIGN(Node));
3091     break;
3092   case ISD::FNEG:
3093     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3094     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3095     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3096     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3097                        Node->getOperand(0));
3098     Results.push_back(Tmp1);
3099     break;
3100   case ISD::FABS:
3101     Results.push_back(ExpandFABS(Node));
3102     break;
3103   case ISD::SMIN:
3104   case ISD::SMAX:
3105   case ISD::UMIN:
3106   case ISD::UMAX: {
3107     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3108     ISD::CondCode Pred;
3109     switch (Node->getOpcode()) {
3110     default: llvm_unreachable("How did we get here?");
3111     case ISD::SMAX: Pred = ISD::SETGT; break;
3112     case ISD::SMIN: Pred = ISD::SETLT; break;
3113     case ISD::UMAX: Pred = ISD::SETUGT; break;
3114     case ISD::UMIN: Pred = ISD::SETULT; break;
3115     }
3116     Tmp1 = Node->getOperand(0);
3117     Tmp2 = Node->getOperand(1);
3118     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3119     Results.push_back(Tmp1);
3120     break;
3121   }
3122   case ISD::FMINNUM:
3123   case ISD::FMAXNUM: {
3124     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3125       Results.push_back(Expanded);
3126     break;
3127   }
3128   case ISD::FSIN:
3129   case ISD::FCOS: {
3130     EVT VT = Node->getValueType(0);
3131     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3132     // fcos which share the same operand and both are used.
3133     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3134          isSinCosLibcallAvailable(Node, TLI))
3135         && useSinCos(Node)) {
3136       SDVTList VTs = DAG.getVTList(VT, VT);
3137       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3138       if (Node->getOpcode() == ISD::FCOS)
3139         Tmp1 = Tmp1.getValue(1);
3140       Results.push_back(Tmp1);
3141     }
3142     break;
3143   }
3144   case ISD::FMAD:
3145     llvm_unreachable("Illegal fmad should never be formed");
3146 
3147   case ISD::FP16_TO_FP:
3148     if (Node->getValueType(0) != MVT::f32) {
3149       // We can extend to types bigger than f32 in two steps without changing
3150       // the result. Since "f16 -> f32" is much more commonly available, give
3151       // CodeGen the option of emitting that before resorting to a libcall.
3152       SDValue Res =
3153           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3154       Results.push_back(
3155           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3156     }
3157     break;
3158   case ISD::FP_TO_FP16:
3159     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3160     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3161       SDValue Op = Node->getOperand(0);
3162       MVT SVT = Op.getSimpleValueType();
3163       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3164           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3165         // Under fastmath, we can expand this node into a fround followed by
3166         // a float-half conversion.
3167         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3168                                        DAG.getIntPtrConstant(0, dl));
3169         Results.push_back(
3170             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3171       }
3172     }
3173     break;
3174   case ISD::ConstantFP: {
3175     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3176     // Check to see if this FP immediate is already legal.
3177     // If this is a legal constant, turn it into a TargetConstantFP node.
3178     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0),
3179                           DAG.getMachineFunction().getFunction().hasOptSize()))
3180       Results.push_back(ExpandConstantFP(CFP, true));
3181     break;
3182   }
3183   case ISD::Constant: {
3184     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3185     Results.push_back(ExpandConstant(CP));
3186     break;
3187   }
3188   case ISD::FSUB: {
3189     EVT VT = Node->getValueType(0);
3190     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3191         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3192       const SDNodeFlags Flags = Node->getFlags();
3193       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3194       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3195       Results.push_back(Tmp1);
3196     }
3197     break;
3198   }
3199   case ISD::SUB: {
3200     EVT VT = Node->getValueType(0);
3201     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3202            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3203            "Don't know how to expand this subtraction!");
3204     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3205                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3206                                VT));
3207     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3208     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3209     break;
3210   }
3211   case ISD::UREM:
3212   case ISD::SREM: {
3213     EVT VT = Node->getValueType(0);
3214     bool isSigned = Node->getOpcode() == ISD::SREM;
3215     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
3216     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3217     Tmp2 = Node->getOperand(0);
3218     Tmp3 = Node->getOperand(1);
3219     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3220       SDVTList VTs = DAG.getVTList(VT, VT);
3221       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
3222       Results.push_back(Tmp1);
3223     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
3224       // X % Y -> X-X/Y*Y
3225       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
3226       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
3227       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
3228       Results.push_back(Tmp1);
3229     }
3230     break;
3231   }
3232   case ISD::UDIV:
3233   case ISD::SDIV: {
3234     bool isSigned = Node->getOpcode() == ISD::SDIV;
3235     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3236     EVT VT = Node->getValueType(0);
3237     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3238       SDVTList VTs = DAG.getVTList(VT, VT);
3239       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3240                          Node->getOperand(1));
3241       Results.push_back(Tmp1);
3242     }
3243     break;
3244   }
3245   case ISD::MULHU:
3246   case ISD::MULHS: {
3247     unsigned ExpandOpcode =
3248         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3249     EVT VT = Node->getValueType(0);
3250     SDVTList VTs = DAG.getVTList(VT, VT);
3251 
3252     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3253                        Node->getOperand(1));
3254     Results.push_back(Tmp1.getValue(1));
3255     break;
3256   }
3257   case ISD::UMUL_LOHI:
3258   case ISD::SMUL_LOHI: {
3259     SDValue LHS = Node->getOperand(0);
3260     SDValue RHS = Node->getOperand(1);
3261     MVT VT = LHS.getSimpleValueType();
3262     unsigned MULHOpcode =
3263         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3264 
3265     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3266       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3267       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3268       break;
3269     }
3270 
3271     SmallVector<SDValue, 4> Halves;
3272     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3273     assert(TLI.isTypeLegal(HalfType));
3274     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, Node, LHS, RHS, Halves,
3275                            HalfType, DAG,
3276                            TargetLowering::MulExpansionKind::Always)) {
3277       for (unsigned i = 0; i < 2; ++i) {
3278         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3279         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3280         SDValue Shift = DAG.getConstant(
3281             HalfType.getScalarSizeInBits(), dl,
3282             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3283         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3284         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3285       }
3286       break;
3287     }
3288     break;
3289   }
3290   case ISD::MUL: {
3291     EVT VT = Node->getValueType(0);
3292     SDVTList VTs = DAG.getVTList(VT, VT);
3293     // See if multiply or divide can be lowered using two-result operations.
3294     // We just need the low half of the multiply; try both the signed
3295     // and unsigned forms. If the target supports both SMUL_LOHI and
3296     // UMUL_LOHI, form a preference by checking which forms of plain
3297     // MULH it supports.
3298     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3299     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3300     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3301     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3302     unsigned OpToUse = 0;
3303     if (HasSMUL_LOHI && !HasMULHS) {
3304       OpToUse = ISD::SMUL_LOHI;
3305     } else if (HasUMUL_LOHI && !HasMULHU) {
3306       OpToUse = ISD::UMUL_LOHI;
3307     } else if (HasSMUL_LOHI) {
3308       OpToUse = ISD::SMUL_LOHI;
3309     } else if (HasUMUL_LOHI) {
3310       OpToUse = ISD::UMUL_LOHI;
3311     }
3312     if (OpToUse) {
3313       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3314                                     Node->getOperand(1)));
3315       break;
3316     }
3317 
3318     SDValue Lo, Hi;
3319     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3320     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3321         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3322         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3323         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3324         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3325                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3326       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3327       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3328       SDValue Shift =
3329           DAG.getConstant(HalfType.getSizeInBits(), dl,
3330                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3331       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3332       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3333     }
3334     break;
3335   }
3336   case ISD::FSHL:
3337   case ISD::FSHR:
3338     if (TLI.expandFunnelShift(Node, Tmp1, DAG))
3339       Results.push_back(Tmp1);
3340     break;
3341   case ISD::ROTL:
3342   case ISD::ROTR:
3343     if (TLI.expandROT(Node, Tmp1, DAG))
3344       Results.push_back(Tmp1);
3345     break;
3346   case ISD::SADDSAT:
3347   case ISD::UADDSAT:
3348   case ISD::SSUBSAT:
3349   case ISD::USUBSAT:
3350     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3351     break;
3352   case ISD::SMULFIX:
3353   case ISD::SMULFIXSAT:
3354   case ISD::UMULFIX:
3355     Results.push_back(TLI.expandFixedPointMul(Node, DAG));
3356     break;
3357   case ISD::ADDCARRY:
3358   case ISD::SUBCARRY: {
3359     SDValue LHS = Node->getOperand(0);
3360     SDValue RHS = Node->getOperand(1);
3361     SDValue Carry = Node->getOperand(2);
3362 
3363     bool IsAdd = Node->getOpcode() == ISD::ADDCARRY;
3364 
3365     // Initial add of the 2 operands.
3366     unsigned Op = IsAdd ? ISD::ADD : ISD::SUB;
3367     EVT VT = LHS.getValueType();
3368     SDValue Sum = DAG.getNode(Op, dl, VT, LHS, RHS);
3369 
3370     // Initial check for overflow.
3371     EVT CarryType = Node->getValueType(1);
3372     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3373     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3374     SDValue Overflow = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3375 
3376     // Add of the sum and the carry.
3377     SDValue CarryExt =
3378         DAG.getZeroExtendInReg(DAG.getZExtOrTrunc(Carry, dl, VT), dl, MVT::i1);
3379     SDValue Sum2 = DAG.getNode(Op, dl, VT, Sum, CarryExt);
3380 
3381     // Second check for overflow. If we are adding, we can only overflow if the
3382     // initial sum is all 1s ang the carry is set, resulting in a new sum of 0.
3383     // If we are subtracting, we can only overflow if the initial sum is 0 and
3384     // the carry is set, resulting in a new sum of all 1s.
3385     SDValue Zero = DAG.getConstant(0, dl, VT);
3386     SDValue Overflow2 =
3387         IsAdd ? DAG.getSetCC(dl, SetCCType, Sum2, Zero, ISD::SETEQ)
3388               : DAG.getSetCC(dl, SetCCType, Sum, Zero, ISD::SETEQ);
3389     Overflow2 = DAG.getNode(ISD::AND, dl, SetCCType, Overflow2,
3390                             DAG.getZExtOrTrunc(Carry, dl, SetCCType));
3391 
3392     SDValue ResultCarry =
3393         DAG.getNode(ISD::OR, dl, SetCCType, Overflow, Overflow2);
3394 
3395     Results.push_back(Sum2);
3396     Results.push_back(DAG.getBoolExtOrTrunc(ResultCarry, dl, CarryType, VT));
3397     break;
3398   }
3399   case ISD::SADDO:
3400   case ISD::SSUBO: {
3401     SDValue Result, Overflow;
3402     TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
3403     Results.push_back(Result);
3404     Results.push_back(Overflow);
3405     break;
3406   }
3407   case ISD::UADDO:
3408   case ISD::USUBO: {
3409     SDValue Result, Overflow;
3410     TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
3411     Results.push_back(Result);
3412     Results.push_back(Overflow);
3413     break;
3414   }
3415   case ISD::UMULO:
3416   case ISD::SMULO: {
3417     SDValue Result, Overflow;
3418     if (TLI.expandMULO(Node, Result, Overflow, DAG)) {
3419       Results.push_back(Result);
3420       Results.push_back(Overflow);
3421     }
3422     break;
3423   }
3424   case ISD::BUILD_PAIR: {
3425     EVT PairTy = Node->getValueType(0);
3426     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3427     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3428     Tmp2 = DAG.getNode(
3429         ISD::SHL, dl, PairTy, Tmp2,
3430         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3431                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3432     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3433     break;
3434   }
3435   case ISD::SELECT:
3436     Tmp1 = Node->getOperand(0);
3437     Tmp2 = Node->getOperand(1);
3438     Tmp3 = Node->getOperand(2);
3439     if (Tmp1.getOpcode() == ISD::SETCC) {
3440       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3441                              Tmp2, Tmp3,
3442                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3443     } else {
3444       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3445                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3446                              Tmp2, Tmp3, ISD::SETNE);
3447     }
3448     Results.push_back(Tmp1);
3449     break;
3450   case ISD::BR_JT: {
3451     SDValue Chain = Node->getOperand(0);
3452     SDValue Table = Node->getOperand(1);
3453     SDValue Index = Node->getOperand(2);
3454 
3455     const DataLayout &TD = DAG.getDataLayout();
3456     EVT PTy = TLI.getPointerTy(TD);
3457 
3458     unsigned EntrySize =
3459       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3460 
3461     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3462     // This transformation needs to be done here since otherwise the MIPS
3463     // backend will end up emitting a three instruction multiply sequence
3464     // instead of a single shift and MSP430 will call a runtime function.
3465     if (llvm::isPowerOf2_32(EntrySize))
3466       Index = DAG.getNode(
3467           ISD::SHL, dl, Index.getValueType(), Index,
3468           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3469     else
3470       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3471                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3472     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3473                                Index, Table);
3474 
3475     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3476     SDValue LD = DAG.getExtLoad(
3477         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3478         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3479     Addr = LD;
3480     if (TLI.isJumpTableRelative()) {
3481       // For PIC, the sequence is:
3482       // BRIND(load(Jumptable + index) + RelocBase)
3483       // RelocBase can be JumpTable, GOT or some sort of global base.
3484       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3485                           TLI.getPICJumpTableRelocBase(Table, DAG));
3486     }
3487 
3488     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3489     Results.push_back(Tmp1);
3490     break;
3491   }
3492   case ISD::BRCOND:
3493     // Expand brcond's setcc into its constituent parts and create a BR_CC
3494     // Node.
3495     Tmp1 = Node->getOperand(0);
3496     Tmp2 = Node->getOperand(1);
3497     if (Tmp2.getOpcode() == ISD::SETCC) {
3498       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3499                          Tmp1, Tmp2.getOperand(2),
3500                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3501                          Node->getOperand(2));
3502     } else {
3503       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3504       if (Tmp2.isUndef() ||
3505           (Tmp2.getOpcode() == ISD::AND &&
3506            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3507            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3508         Tmp3 = Tmp2;
3509       else
3510         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3511                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3512       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3513                          DAG.getCondCode(ISD::SETNE), Tmp3,
3514                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3515                          Node->getOperand(2));
3516     }
3517     Results.push_back(Tmp1);
3518     break;
3519   case ISD::SETCC: {
3520     Tmp1 = Node->getOperand(0);
3521     Tmp2 = Node->getOperand(1);
3522     Tmp3 = Node->getOperand(2);
3523     bool Legalized = LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2,
3524                                            Tmp3, NeedInvert, dl);
3525 
3526     if (Legalized) {
3527       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3528       // condition code, create a new SETCC node.
3529       if (Tmp3.getNode())
3530         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3531                            Tmp1, Tmp2, Tmp3);
3532 
3533       // If we expanded the SETCC by inverting the condition code, then wrap
3534       // the existing SETCC in a NOT to restore the intended condition.
3535       if (NeedInvert)
3536         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3537 
3538       Results.push_back(Tmp1);
3539       break;
3540     }
3541 
3542     // Otherwise, SETCC for the given comparison type must be completely
3543     // illegal; expand it into a SELECT_CC.
3544     EVT VT = Node->getValueType(0);
3545     int TrueValue;
3546     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3547     case TargetLowering::ZeroOrOneBooleanContent:
3548     case TargetLowering::UndefinedBooleanContent:
3549       TrueValue = 1;
3550       break;
3551     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3552       TrueValue = -1;
3553       break;
3554     }
3555     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3556                        DAG.getConstant(TrueValue, dl, VT),
3557                        DAG.getConstant(0, dl, VT),
3558                        Tmp3);
3559     Results.push_back(Tmp1);
3560     break;
3561   }
3562   case ISD::SELECT_CC: {
3563     Tmp1 = Node->getOperand(0);   // LHS
3564     Tmp2 = Node->getOperand(1);   // RHS
3565     Tmp3 = Node->getOperand(2);   // True
3566     Tmp4 = Node->getOperand(3);   // False
3567     EVT VT = Node->getValueType(0);
3568     SDValue CC = Node->getOperand(4);
3569     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3570 
3571     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3572       // If the condition code is legal, then we need to expand this
3573       // node using SETCC and SELECT.
3574       EVT CmpVT = Tmp1.getValueType();
3575       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3576              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3577              "expanded.");
3578       EVT CCVT =
3579           TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), CmpVT);
3580       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC);
3581       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3582       break;
3583     }
3584 
3585     // SELECT_CC is legal, so the condition code must not be.
3586     bool Legalized = false;
3587     // Try to legalize by inverting the condition.  This is for targets that
3588     // might support an ordered version of a condition, but not the unordered
3589     // version (or vice versa).
3590     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp,
3591                                                Tmp1.getValueType().isInteger());
3592     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3593       // Use the new condition code and swap true and false
3594       Legalized = true;
3595       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3596     } else {
3597       // If The inverse is not legal, then try to swap the arguments using
3598       // the inverse condition code.
3599       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3600       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3601         // The swapped inverse condition is legal, so swap true and false,
3602         // lhs and rhs.
3603         Legalized = true;
3604         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3605       }
3606     }
3607 
3608     if (!Legalized) {
3609       Legalized = LegalizeSetCCCondCode(
3610           getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC, NeedInvert,
3611           dl);
3612 
3613       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3614 
3615       // If we expanded the SETCC by inverting the condition code, then swap
3616       // the True/False operands to match.
3617       if (NeedInvert)
3618         std::swap(Tmp3, Tmp4);
3619 
3620       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3621       // condition code, create a new SELECT_CC node.
3622       if (CC.getNode()) {
3623         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3624                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3625       } else {
3626         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3627         CC = DAG.getCondCode(ISD::SETNE);
3628         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3629                            Tmp2, Tmp3, Tmp4, CC);
3630       }
3631     }
3632     Results.push_back(Tmp1);
3633     break;
3634   }
3635   case ISD::BR_CC: {
3636     Tmp1 = Node->getOperand(0);              // Chain
3637     Tmp2 = Node->getOperand(2);              // LHS
3638     Tmp3 = Node->getOperand(3);              // RHS
3639     Tmp4 = Node->getOperand(1);              // CC
3640 
3641     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
3642         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, NeedInvert, dl);
3643     (void)Legalized;
3644     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3645 
3646     assert(!NeedInvert && "Don't know how to invert BR_CC!");
3647 
3648     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3649     // node.
3650     if (Tmp4.getNode()) {
3651       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3652                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3653     } else {
3654       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3655       Tmp4 = DAG.getCondCode(ISD::SETNE);
3656       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3657                          Tmp2, Tmp3, Node->getOperand(4));
3658     }
3659     Results.push_back(Tmp1);
3660     break;
3661   }
3662   case ISD::BUILD_VECTOR:
3663     Results.push_back(ExpandBUILD_VECTOR(Node));
3664     break;
3665   case ISD::SRA:
3666   case ISD::SRL:
3667   case ISD::SHL: {
3668     // Scalarize vector SRA/SRL/SHL.
3669     EVT VT = Node->getValueType(0);
3670     assert(VT.isVector() && "Unable to legalize non-vector shift");
3671     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3672     unsigned NumElem = VT.getVectorNumElements();
3673 
3674     SmallVector<SDValue, 8> Scalars;
3675     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3676       SDValue Ex = DAG.getNode(
3677           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(0),
3678           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3679       SDValue Sh = DAG.getNode(
3680           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(1),
3681           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3682       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3683                                     VT.getScalarType(), Ex, Sh));
3684     }
3685 
3686     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3687     ReplaceNode(SDValue(Node, 0), Result);
3688     break;
3689   }
3690   case ISD::VECREDUCE_FADD:
3691   case ISD::VECREDUCE_FMUL:
3692   case ISD::VECREDUCE_ADD:
3693   case ISD::VECREDUCE_MUL:
3694   case ISD::VECREDUCE_AND:
3695   case ISD::VECREDUCE_OR:
3696   case ISD::VECREDUCE_XOR:
3697   case ISD::VECREDUCE_SMAX:
3698   case ISD::VECREDUCE_SMIN:
3699   case ISD::VECREDUCE_UMAX:
3700   case ISD::VECREDUCE_UMIN:
3701   case ISD::VECREDUCE_FMAX:
3702   case ISD::VECREDUCE_FMIN:
3703     Results.push_back(TLI.expandVecReduce(Node, DAG));
3704     break;
3705   case ISD::GLOBAL_OFFSET_TABLE:
3706   case ISD::GlobalAddress:
3707   case ISD::GlobalTLSAddress:
3708   case ISD::ExternalSymbol:
3709   case ISD::ConstantPool:
3710   case ISD::JumpTable:
3711   case ISD::INTRINSIC_W_CHAIN:
3712   case ISD::INTRINSIC_WO_CHAIN:
3713   case ISD::INTRINSIC_VOID:
3714     // FIXME: Custom lowering for these operations shouldn't return null!
3715     break;
3716   }
3717 
3718   // Replace the original node with the legalized result.
3719   if (Results.empty()) {
3720     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3721     return false;
3722   }
3723 
3724   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3725   ReplaceNode(Node, Results.data());
3726   return true;
3727 }
3728 
3729 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3730   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3731   SmallVector<SDValue, 8> Results;
3732   SDLoc dl(Node);
3733   // FIXME: Check flags on the node to see if we can use a finite call.
3734   bool CanUseFiniteLibCall = TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath;
3735   unsigned Opc = Node->getOpcode();
3736   switch (Opc) {
3737   case ISD::ATOMIC_FENCE: {
3738     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3739     // FIXME: handle "fence singlethread" more efficiently.
3740     TargetLowering::ArgListTy Args;
3741 
3742     TargetLowering::CallLoweringInfo CLI(DAG);
3743     CLI.setDebugLoc(dl)
3744         .setChain(Node->getOperand(0))
3745         .setLibCallee(
3746             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3747             DAG.getExternalSymbol("__sync_synchronize",
3748                                   TLI.getPointerTy(DAG.getDataLayout())),
3749             std::move(Args));
3750 
3751     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3752 
3753     Results.push_back(CallResult.second);
3754     break;
3755   }
3756   // By default, atomic intrinsics are marked Legal and lowered. Targets
3757   // which don't support them directly, however, may want libcalls, in which
3758   // case they mark them Expand, and we get here.
3759   case ISD::ATOMIC_SWAP:
3760   case ISD::ATOMIC_LOAD_ADD:
3761   case ISD::ATOMIC_LOAD_SUB:
3762   case ISD::ATOMIC_LOAD_AND:
3763   case ISD::ATOMIC_LOAD_CLR:
3764   case ISD::ATOMIC_LOAD_OR:
3765   case ISD::ATOMIC_LOAD_XOR:
3766   case ISD::ATOMIC_LOAD_NAND:
3767   case ISD::ATOMIC_LOAD_MIN:
3768   case ISD::ATOMIC_LOAD_MAX:
3769   case ISD::ATOMIC_LOAD_UMIN:
3770   case ISD::ATOMIC_LOAD_UMAX:
3771   case ISD::ATOMIC_CMP_SWAP: {
3772     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3773     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
3774     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
3775 
3776     std::pair<SDValue, SDValue> Tmp = ExpandChainLibCall(LC, Node, false);
3777     Results.push_back(Tmp.first);
3778     Results.push_back(Tmp.second);
3779     break;
3780   }
3781   case ISD::TRAP: {
3782     // If this operation is not supported, lower it to 'abort()' call
3783     TargetLowering::ArgListTy Args;
3784     TargetLowering::CallLoweringInfo CLI(DAG);
3785     CLI.setDebugLoc(dl)
3786         .setChain(Node->getOperand(0))
3787         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3788                       DAG.getExternalSymbol(
3789                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
3790                       std::move(Args));
3791     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3792 
3793     Results.push_back(CallResult.second);
3794     break;
3795   }
3796   case ISD::FMINNUM:
3797   case ISD::STRICT_FMINNUM:
3798     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
3799                                       RTLIB::FMIN_F80, RTLIB::FMIN_F128,
3800                                       RTLIB::FMIN_PPCF128));
3801     break;
3802   case ISD::FMAXNUM:
3803   case ISD::STRICT_FMAXNUM:
3804     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
3805                                       RTLIB::FMAX_F80, RTLIB::FMAX_F128,
3806                                       RTLIB::FMAX_PPCF128));
3807     break;
3808   case ISD::FSQRT:
3809   case ISD::STRICT_FSQRT:
3810     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
3811                                       RTLIB::SQRT_F80, RTLIB::SQRT_F128,
3812                                       RTLIB::SQRT_PPCF128));
3813     break;
3814   case ISD::FCBRT:
3815     Results.push_back(ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
3816                                       RTLIB::CBRT_F80, RTLIB::CBRT_F128,
3817                                       RTLIB::CBRT_PPCF128));
3818     break;
3819   case ISD::FSIN:
3820   case ISD::STRICT_FSIN:
3821     Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
3822                                       RTLIB::SIN_F80, RTLIB::SIN_F128,
3823                                       RTLIB::SIN_PPCF128));
3824     break;
3825   case ISD::FCOS:
3826   case ISD::STRICT_FCOS:
3827     Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
3828                                       RTLIB::COS_F80, RTLIB::COS_F128,
3829                                       RTLIB::COS_PPCF128));
3830     break;
3831   case ISD::FSINCOS:
3832     // Expand into sincos libcall.
3833     ExpandSinCosLibCall(Node, Results);
3834     break;
3835   case ISD::FLOG:
3836   case ISD::STRICT_FLOG:
3837     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log_finite))
3838       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_FINITE_F32,
3839                                         RTLIB::LOG_FINITE_F64,
3840                                         RTLIB::LOG_FINITE_F80,
3841                                         RTLIB::LOG_FINITE_F128,
3842                                         RTLIB::LOG_FINITE_PPCF128));
3843     else
3844       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
3845                                         RTLIB::LOG_F80, RTLIB::LOG_F128,
3846                                         RTLIB::LOG_PPCF128));
3847     break;
3848   case ISD::FLOG2:
3849   case ISD::STRICT_FLOG2:
3850     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log2_finite))
3851       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_FINITE_F32,
3852                                         RTLIB::LOG2_FINITE_F64,
3853                                         RTLIB::LOG2_FINITE_F80,
3854                                         RTLIB::LOG2_FINITE_F128,
3855                                         RTLIB::LOG2_FINITE_PPCF128));
3856     else
3857       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
3858                                         RTLIB::LOG2_F80, RTLIB::LOG2_F128,
3859                                         RTLIB::LOG2_PPCF128));
3860     break;
3861   case ISD::FLOG10:
3862   case ISD::STRICT_FLOG10:
3863     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log10_finite))
3864       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_FINITE_F32,
3865                                         RTLIB::LOG10_FINITE_F64,
3866                                         RTLIB::LOG10_FINITE_F80,
3867                                         RTLIB::LOG10_FINITE_F128,
3868                                         RTLIB::LOG10_FINITE_PPCF128));
3869     else
3870       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
3871                                         RTLIB::LOG10_F80, RTLIB::LOG10_F128,
3872                                         RTLIB::LOG10_PPCF128));
3873     break;
3874   case ISD::FEXP:
3875   case ISD::STRICT_FEXP:
3876     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp_finite))
3877       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_FINITE_F32,
3878                                         RTLIB::EXP_FINITE_F64,
3879                                         RTLIB::EXP_FINITE_F80,
3880                                         RTLIB::EXP_FINITE_F128,
3881                                         RTLIB::EXP_FINITE_PPCF128));
3882     else
3883       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
3884                                         RTLIB::EXP_F80, RTLIB::EXP_F128,
3885                                         RTLIB::EXP_PPCF128));
3886     break;
3887   case ISD::FEXP2:
3888   case ISD::STRICT_FEXP2:
3889     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp2_finite))
3890       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_FINITE_F32,
3891                                         RTLIB::EXP2_FINITE_F64,
3892                                         RTLIB::EXP2_FINITE_F80,
3893                                         RTLIB::EXP2_FINITE_F128,
3894                                         RTLIB::EXP2_FINITE_PPCF128));
3895     else
3896       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
3897                                         RTLIB::EXP2_F80, RTLIB::EXP2_F128,
3898                                         RTLIB::EXP2_PPCF128));
3899     break;
3900   case ISD::FTRUNC:
3901   case ISD::STRICT_FTRUNC:
3902     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
3903                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
3904                                       RTLIB::TRUNC_PPCF128));
3905     break;
3906   case ISD::FFLOOR:
3907   case ISD::STRICT_FFLOOR:
3908     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
3909                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
3910                                       RTLIB::FLOOR_PPCF128));
3911     break;
3912   case ISD::FCEIL:
3913   case ISD::STRICT_FCEIL:
3914     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
3915                                       RTLIB::CEIL_F80, RTLIB::CEIL_F128,
3916                                       RTLIB::CEIL_PPCF128));
3917     break;
3918   case ISD::FRINT:
3919   case ISD::STRICT_FRINT:
3920     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
3921                                       RTLIB::RINT_F80, RTLIB::RINT_F128,
3922                                       RTLIB::RINT_PPCF128));
3923     break;
3924   case ISD::FNEARBYINT:
3925   case ISD::STRICT_FNEARBYINT:
3926     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
3927                                       RTLIB::NEARBYINT_F64,
3928                                       RTLIB::NEARBYINT_F80,
3929                                       RTLIB::NEARBYINT_F128,
3930                                       RTLIB::NEARBYINT_PPCF128));
3931     break;
3932   case ISD::FROUND:
3933   case ISD::STRICT_FROUND:
3934     Results.push_back(ExpandFPLibCall(Node, RTLIB::ROUND_F32,
3935                                       RTLIB::ROUND_F64,
3936                                       RTLIB::ROUND_F80,
3937                                       RTLIB::ROUND_F128,
3938                                       RTLIB::ROUND_PPCF128));
3939     break;
3940   case ISD::FPOWI:
3941   case ISD::STRICT_FPOWI:
3942     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
3943                                       RTLIB::POWI_F80, RTLIB::POWI_F128,
3944                                       RTLIB::POWI_PPCF128));
3945     break;
3946   case ISD::FPOW:
3947   case ISD::STRICT_FPOW:
3948     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_pow_finite))
3949       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_FINITE_F32,
3950                                         RTLIB::POW_FINITE_F64,
3951                                         RTLIB::POW_FINITE_F80,
3952                                         RTLIB::POW_FINITE_F128,
3953                                         RTLIB::POW_FINITE_PPCF128));
3954     else
3955       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
3956                                         RTLIB::POW_F80, RTLIB::POW_F128,
3957                                         RTLIB::POW_PPCF128));
3958     break;
3959   case ISD::FDIV:
3960     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
3961                                       RTLIB::DIV_F80, RTLIB::DIV_F128,
3962                                       RTLIB::DIV_PPCF128));
3963     break;
3964   case ISD::FREM:
3965   case ISD::STRICT_FREM:
3966     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
3967                                       RTLIB::REM_F80, RTLIB::REM_F128,
3968                                       RTLIB::REM_PPCF128));
3969     break;
3970   case ISD::FMA:
3971   case ISD::STRICT_FMA:
3972     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
3973                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
3974                                       RTLIB::FMA_PPCF128));
3975     break;
3976   case ISD::FADD:
3977     Results.push_back(ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
3978                                       RTLIB::ADD_F80, RTLIB::ADD_F128,
3979                                       RTLIB::ADD_PPCF128));
3980     break;
3981   case ISD::FMUL:
3982     Results.push_back(ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
3983                                       RTLIB::MUL_F80, RTLIB::MUL_F128,
3984                                       RTLIB::MUL_PPCF128));
3985     break;
3986   case ISD::FP16_TO_FP:
3987     if (Node->getValueType(0) == MVT::f32) {
3988       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
3989     }
3990     break;
3991   case ISD::FP_TO_FP16: {
3992     RTLIB::Libcall LC =
3993         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
3994     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
3995     Results.push_back(ExpandLibCall(LC, Node, false));
3996     break;
3997   }
3998   case ISD::FSUB:
3999     Results.push_back(ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4000                                       RTLIB::SUB_F80, RTLIB::SUB_F128,
4001                                       RTLIB::SUB_PPCF128));
4002     break;
4003   case ISD::SREM:
4004     Results.push_back(ExpandIntLibCall(Node, true,
4005                                        RTLIB::SREM_I8,
4006                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4007                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4008     break;
4009   case ISD::UREM:
4010     Results.push_back(ExpandIntLibCall(Node, false,
4011                                        RTLIB::UREM_I8,
4012                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4013                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4014     break;
4015   case ISD::SDIV:
4016     Results.push_back(ExpandIntLibCall(Node, true,
4017                                        RTLIB::SDIV_I8,
4018                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4019                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4020     break;
4021   case ISD::UDIV:
4022     Results.push_back(ExpandIntLibCall(Node, false,
4023                                        RTLIB::UDIV_I8,
4024                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4025                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4026     break;
4027   case ISD::SDIVREM:
4028   case ISD::UDIVREM:
4029     // Expand into divrem libcall
4030     ExpandDivRemLibCall(Node, Results);
4031     break;
4032   case ISD::MUL:
4033     Results.push_back(ExpandIntLibCall(Node, false,
4034                                        RTLIB::MUL_I8,
4035                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4036                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4037     break;
4038   case ISD::CTLZ_ZERO_UNDEF:
4039     switch (Node->getSimpleValueType(0).SimpleTy) {
4040     default:
4041       llvm_unreachable("LibCall explicitly requested, but not available");
4042     case MVT::i32:
4043       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4044       break;
4045     case MVT::i64:
4046       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4047       break;
4048     case MVT::i128:
4049       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4050       break;
4051     }
4052     break;
4053   }
4054 
4055   // Replace the original node with the legalized result.
4056   if (!Results.empty()) {
4057     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4058     ReplaceNode(Node, Results.data());
4059   } else
4060     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4061 }
4062 
4063 // Determine the vector type to use in place of an original scalar element when
4064 // promoting equally sized vectors.
4065 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4066                                         MVT EltVT, MVT NewEltVT) {
4067   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4068   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4069   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4070   return MidVT;
4071 }
4072 
4073 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4074   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4075   SmallVector<SDValue, 8> Results;
4076   MVT OVT = Node->getSimpleValueType(0);
4077   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4078       Node->getOpcode() == ISD::SINT_TO_FP ||
4079       Node->getOpcode() == ISD::SETCC ||
4080       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4081       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4082     OVT = Node->getOperand(0).getSimpleValueType();
4083   }
4084   if (Node->getOpcode() == ISD::BR_CC)
4085     OVT = Node->getOperand(2).getSimpleValueType();
4086   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4087   SDLoc dl(Node);
4088   SDValue Tmp1, Tmp2, Tmp3;
4089   switch (Node->getOpcode()) {
4090   case ISD::CTTZ:
4091   case ISD::CTTZ_ZERO_UNDEF:
4092   case ISD::CTLZ:
4093   case ISD::CTLZ_ZERO_UNDEF:
4094   case ISD::CTPOP:
4095     // Zero extend the argument.
4096     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4097     if (Node->getOpcode() == ISD::CTTZ) {
4098       // The count is the same in the promoted type except if the original
4099       // value was zero.  This can be handled by setting the bit just off
4100       // the top of the original type.
4101       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4102                                         OVT.getSizeInBits());
4103       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4104                          DAG.getConstant(TopBit, dl, NVT));
4105     }
4106     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4107     // already the correct result.
4108     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4109     if (Node->getOpcode() == ISD::CTLZ ||
4110         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4111       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4112       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4113                           DAG.getConstant(NVT.getSizeInBits() -
4114                                           OVT.getSizeInBits(), dl, NVT));
4115     }
4116     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4117     break;
4118   case ISD::BITREVERSE:
4119   case ISD::BSWAP: {
4120     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4121     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4122     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4123     Tmp1 = DAG.getNode(
4124         ISD::SRL, dl, NVT, Tmp1,
4125         DAG.getConstant(DiffBits, dl,
4126                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4127 
4128     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4129     break;
4130   }
4131   case ISD::FP_TO_UINT:
4132   case ISD::FP_TO_SINT:
4133     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
4134                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
4135     Results.push_back(Tmp1);
4136     break;
4137   case ISD::UINT_TO_FP:
4138   case ISD::SINT_TO_FP:
4139     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
4140                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
4141     Results.push_back(Tmp1);
4142     break;
4143   case ISD::VAARG: {
4144     SDValue Chain = Node->getOperand(0); // Get the chain.
4145     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4146 
4147     unsigned TruncOp;
4148     if (OVT.isVector()) {
4149       TruncOp = ISD::BITCAST;
4150     } else {
4151       assert(OVT.isInteger()
4152         && "VAARG promotion is supported only for vectors or integer types");
4153       TruncOp = ISD::TRUNCATE;
4154     }
4155 
4156     // Perform the larger operation, then convert back
4157     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4158              Node->getConstantOperandVal(3));
4159     Chain = Tmp1.getValue(1);
4160 
4161     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4162 
4163     // Modified the chain result - switch anything that used the old chain to
4164     // use the new one.
4165     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4166     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4167     if (UpdatedNodes) {
4168       UpdatedNodes->insert(Tmp2.getNode());
4169       UpdatedNodes->insert(Chain.getNode());
4170     }
4171     ReplacedNode(Node);
4172     break;
4173   }
4174   case ISD::MUL:
4175   case ISD::SDIV:
4176   case ISD::SREM:
4177   case ISD::UDIV:
4178   case ISD::UREM:
4179   case ISD::AND:
4180   case ISD::OR:
4181   case ISD::XOR: {
4182     unsigned ExtOp, TruncOp;
4183     if (OVT.isVector()) {
4184       ExtOp   = ISD::BITCAST;
4185       TruncOp = ISD::BITCAST;
4186     } else {
4187       assert(OVT.isInteger() && "Cannot promote logic operation");
4188 
4189       switch (Node->getOpcode()) {
4190       default:
4191         ExtOp = ISD::ANY_EXTEND;
4192         break;
4193       case ISD::SDIV:
4194       case ISD::SREM:
4195         ExtOp = ISD::SIGN_EXTEND;
4196         break;
4197       case ISD::UDIV:
4198       case ISD::UREM:
4199         ExtOp = ISD::ZERO_EXTEND;
4200         break;
4201       }
4202       TruncOp = ISD::TRUNCATE;
4203     }
4204     // Promote each of the values to the new type.
4205     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4206     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4207     // Perform the larger operation, then convert back
4208     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4209     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4210     break;
4211   }
4212   case ISD::UMUL_LOHI:
4213   case ISD::SMUL_LOHI: {
4214     // Promote to a multiply in a wider integer type.
4215     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4216                                                          : ISD::SIGN_EXTEND;
4217     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4218     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4219     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4220 
4221     auto &DL = DAG.getDataLayout();
4222     unsigned OriginalSize = OVT.getScalarSizeInBits();
4223     Tmp2 = DAG.getNode(
4224         ISD::SRL, dl, NVT, Tmp1,
4225         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4226     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4227     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4228     break;
4229   }
4230   case ISD::SELECT: {
4231     unsigned ExtOp, TruncOp;
4232     if (Node->getValueType(0).isVector() ||
4233         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4234       ExtOp   = ISD::BITCAST;
4235       TruncOp = ISD::BITCAST;
4236     } else if (Node->getValueType(0).isInteger()) {
4237       ExtOp   = ISD::ANY_EXTEND;
4238       TruncOp = ISD::TRUNCATE;
4239     } else {
4240       ExtOp   = ISD::FP_EXTEND;
4241       TruncOp = ISD::FP_ROUND;
4242     }
4243     Tmp1 = Node->getOperand(0);
4244     // Promote each of the values to the new type.
4245     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4246     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4247     // Perform the larger operation, then round down.
4248     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4249     if (TruncOp != ISD::FP_ROUND)
4250       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4251     else
4252       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4253                          DAG.getIntPtrConstant(0, dl));
4254     Results.push_back(Tmp1);
4255     break;
4256   }
4257   case ISD::VECTOR_SHUFFLE: {
4258     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4259 
4260     // Cast the two input vectors.
4261     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4262     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4263 
4264     // Convert the shuffle mask to the right # elements.
4265     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4266     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4267     Results.push_back(Tmp1);
4268     break;
4269   }
4270   case ISD::SETCC: {
4271     unsigned ExtOp = ISD::FP_EXTEND;
4272     if (NVT.isInteger()) {
4273       ISD::CondCode CCCode =
4274         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4275       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4276     }
4277     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4278     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4279     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
4280                                   Tmp1, Tmp2, Node->getOperand(2)));
4281     break;
4282   }
4283   case ISD::BR_CC: {
4284     unsigned ExtOp = ISD::FP_EXTEND;
4285     if (NVT.isInteger()) {
4286       ISD::CondCode CCCode =
4287         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4288       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4289     }
4290     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4291     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4292     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4293                                   Node->getOperand(0), Node->getOperand(1),
4294                                   Tmp1, Tmp2, Node->getOperand(4)));
4295     break;
4296   }
4297   case ISD::FADD:
4298   case ISD::FSUB:
4299   case ISD::FMUL:
4300   case ISD::FDIV:
4301   case ISD::FREM:
4302   case ISD::FMINNUM:
4303   case ISD::FMAXNUM:
4304   case ISD::FPOW:
4305     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4306     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4307     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4308                        Node->getFlags());
4309     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4310                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4311     break;
4312   case ISD::FMA:
4313     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4314     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4315     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4316     Results.push_back(
4317         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4318                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4319                     DAG.getIntPtrConstant(0, dl)));
4320     break;
4321   case ISD::FCOPYSIGN:
4322   case ISD::FPOWI: {
4323     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4324     Tmp2 = Node->getOperand(1);
4325     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4326 
4327     // fcopysign doesn't change anything but the sign bit, so
4328     //   (fp_round (fcopysign (fpext a), b))
4329     // is as precise as
4330     //   (fp_round (fpext a))
4331     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4332     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4333     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4334                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4335     break;
4336   }
4337   case ISD::FFLOOR:
4338   case ISD::FCEIL:
4339   case ISD::FRINT:
4340   case ISD::FNEARBYINT:
4341   case ISD::FROUND:
4342   case ISD::FTRUNC:
4343   case ISD::FNEG:
4344   case ISD::FSQRT:
4345   case ISD::FSIN:
4346   case ISD::FCOS:
4347   case ISD::FLOG:
4348   case ISD::FLOG2:
4349   case ISD::FLOG10:
4350   case ISD::FABS:
4351   case ISD::FEXP:
4352   case ISD::FEXP2:
4353     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4354     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4355     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4356                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4357     break;
4358   case ISD::BUILD_VECTOR: {
4359     MVT EltVT = OVT.getVectorElementType();
4360     MVT NewEltVT = NVT.getVectorElementType();
4361 
4362     // Handle bitcasts to a different vector type with the same total bit size
4363     //
4364     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4365     //  =>
4366     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4367 
4368     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4369            "Invalid promote type for build_vector");
4370     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4371 
4372     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4373 
4374     SmallVector<SDValue, 8> NewOps;
4375     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4376       SDValue Op = Node->getOperand(I);
4377       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4378     }
4379 
4380     SDLoc SL(Node);
4381     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4382     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4383     Results.push_back(CvtVec);
4384     break;
4385   }
4386   case ISD::EXTRACT_VECTOR_ELT: {
4387     MVT EltVT = OVT.getVectorElementType();
4388     MVT NewEltVT = NVT.getVectorElementType();
4389 
4390     // Handle bitcasts to a different vector type with the same total bit size.
4391     //
4392     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4393     //  =>
4394     //  v4i32:castx = bitcast x:v2i64
4395     //
4396     // i64 = bitcast
4397     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4398     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4399     //
4400 
4401     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4402            "Invalid promote type for extract_vector_elt");
4403     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4404 
4405     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4406     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4407 
4408     SDValue Idx = Node->getOperand(1);
4409     EVT IdxVT = Idx.getValueType();
4410     SDLoc SL(Node);
4411     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4412     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4413 
4414     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4415 
4416     SmallVector<SDValue, 8> NewOps;
4417     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4418       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4419       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4420 
4421       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4422                                 CastVec, TmpIdx);
4423       NewOps.push_back(Elt);
4424     }
4425 
4426     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4427     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4428     break;
4429   }
4430   case ISD::INSERT_VECTOR_ELT: {
4431     MVT EltVT = OVT.getVectorElementType();
4432     MVT NewEltVT = NVT.getVectorElementType();
4433 
4434     // Handle bitcasts to a different vector type with the same total bit size
4435     //
4436     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4437     //  =>
4438     //  v4i32:castx = bitcast x:v2i64
4439     //  v2i32:casty = bitcast y:i64
4440     //
4441     // v2i64 = bitcast
4442     //   (v4i32 insert_vector_elt
4443     //       (v4i32 insert_vector_elt v4i32:castx,
4444     //                                (extract_vector_elt casty, 0), 2 * z),
4445     //        (extract_vector_elt casty, 1), (2 * z + 1))
4446 
4447     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4448            "Invalid promote type for insert_vector_elt");
4449     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4450 
4451     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4452     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4453 
4454     SDValue Val = Node->getOperand(1);
4455     SDValue Idx = Node->getOperand(2);
4456     EVT IdxVT = Idx.getValueType();
4457     SDLoc SL(Node);
4458 
4459     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4460     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4461 
4462     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4463     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4464 
4465     SDValue NewVec = CastVec;
4466     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4467       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4468       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4469 
4470       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4471                                 CastVal, IdxOffset);
4472 
4473       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4474                            NewVec, Elt, InEltIdx);
4475     }
4476 
4477     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4478     break;
4479   }
4480   case ISD::SCALAR_TO_VECTOR: {
4481     MVT EltVT = OVT.getVectorElementType();
4482     MVT NewEltVT = NVT.getVectorElementType();
4483 
4484     // Handle bitcasts to different vector type with the same total bit size.
4485     //
4486     // e.g. v2i64 = scalar_to_vector x:i64
4487     //   =>
4488     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4489     //
4490 
4491     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4492     SDValue Val = Node->getOperand(0);
4493     SDLoc SL(Node);
4494 
4495     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4496     SDValue Undef = DAG.getUNDEF(MidVT);
4497 
4498     SmallVector<SDValue, 8> NewElts;
4499     NewElts.push_back(CastVal);
4500     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4501       NewElts.push_back(Undef);
4502 
4503     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4504     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4505     Results.push_back(CvtVec);
4506     break;
4507   }
4508   case ISD::ATOMIC_SWAP: {
4509     AtomicSDNode *AM = cast<AtomicSDNode>(Node);
4510     SDLoc SL(Node);
4511     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NVT, AM->getVal());
4512     assert(NVT.getSizeInBits() == OVT.getSizeInBits() &&
4513            "unexpected promotion type");
4514     assert(AM->getMemoryVT().getSizeInBits() == NVT.getSizeInBits() &&
4515            "unexpected atomic_swap with illegal type");
4516 
4517     SDValue NewAtomic
4518       = DAG.getAtomic(ISD::ATOMIC_SWAP, SL, NVT,
4519                       DAG.getVTList(NVT, MVT::Other),
4520                       { AM->getChain(), AM->getBasePtr(), CastVal },
4521                       AM->getMemOperand());
4522     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewAtomic));
4523     Results.push_back(NewAtomic.getValue(1));
4524     break;
4525   }
4526   }
4527 
4528   // Replace the original node with the legalized result.
4529   if (!Results.empty()) {
4530     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4531     ReplaceNode(Node, Results.data());
4532   } else
4533     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4534 }
4535 
4536 /// This is the entry point for the file.
4537 void SelectionDAG::Legalize() {
4538   AssignTopologicalOrder();
4539 
4540   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4541   // Use a delete listener to remove nodes which were deleted during
4542   // legalization from LegalizeNodes. This is needed to handle the situation
4543   // where a new node is allocated by the object pool to the same address of a
4544   // previously deleted node.
4545   DAGNodeDeletedListener DeleteListener(
4546       *this,
4547       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4548 
4549   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4550 
4551   // Visit all the nodes. We start in topological order, so that we see
4552   // nodes with their original operands intact. Legalization can produce
4553   // new nodes which may themselves need to be legalized. Iterate until all
4554   // nodes have been legalized.
4555   while (true) {
4556     bool AnyLegalized = false;
4557     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4558       --NI;
4559 
4560       SDNode *N = &*NI;
4561       if (N->use_empty() && N != getRoot().getNode()) {
4562         ++NI;
4563         DeleteNode(N);
4564         continue;
4565       }
4566 
4567       if (LegalizedNodes.insert(N).second) {
4568         AnyLegalized = true;
4569         Legalizer.LegalizeOp(N);
4570 
4571         if (N->use_empty() && N != getRoot().getNode()) {
4572           ++NI;
4573           DeleteNode(N);
4574         }
4575       }
4576     }
4577     if (!AnyLegalized)
4578       break;
4579 
4580   }
4581 
4582   // Remove dead nodes now.
4583   RemoveDeadNodes();
4584 }
4585 
4586 bool SelectionDAG::LegalizeOp(SDNode *N,
4587                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4588   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4589   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4590 
4591   // Directly insert the node in question, and legalize it. This will recurse
4592   // as needed through operands.
4593   LegalizedNodes.insert(N);
4594   Legalizer.LegalizeOp(N);
4595 
4596   return LegalizedNodes.count(N);
4597 }
4598