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