1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the SelectionDAG::Legalize method.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/APFloat.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/SetVector.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/SmallSet.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/CodeGen/ISDOpcodes.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/RuntimeLibcalls.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGNodes.h"
28 #include "llvm/CodeGen/TargetFrameLowering.h"
29 #include "llvm/CodeGen/TargetLowering.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/CodeGen/ValueTypes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/MachineValueType.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include <algorithm>
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
getSetCCResultType(EVT VT) const97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
SelectionDAGLegalize(SelectionDAG & DAG,SmallPtrSetImpl<SDNode * > & LegalizedNodes,SmallSetVector<SDNode *,16> * UpdatedNodes=nullptr)104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
137                              bool &NeedInvert, const SDLoc &dl);
138 
139   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
140   SDValue ExpandLibCall(RTLIB::Libcall LC, EVT RetVT, const SDValue *Ops,
141                         unsigned NumOps, bool isSigned, const SDLoc &dl);
142 
143   std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
144                                                  SDNode *Node, bool isSigned);
145   SDValue ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
146                           RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
147                           RTLIB::Libcall Call_F128,
148                           RTLIB::Libcall Call_PPCF128);
149   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
150                            RTLIB::Libcall Call_I8,
151                            RTLIB::Libcall Call_I16,
152                            RTLIB::Libcall Call_I32,
153                            RTLIB::Libcall Call_I64,
154                            RTLIB::Libcall Call_I128);
155   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
156   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
157 
158   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
159                            const SDLoc &dl);
160   SDValue ExpandBUILD_VECTOR(SDNode *Node);
161   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
162   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
163                                 SmallVectorImpl<SDValue> &Results);
164   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
165                          SDValue Value) const;
166   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
167                           SDValue NewIntValue) const;
168   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
169   SDValue ExpandFABS(SDNode *Node) const;
170   SDValue ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0, EVT DestVT,
171                                const SDLoc &dl);
172   SDValue PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT, bool isSigned,
173                                 const SDLoc &dl);
174   SDValue PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT, bool isSigned,
175                                 const SDLoc &dl);
176 
177   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
178   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
179 
180   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
181   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
182   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
183 
184   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
185   SDValue ExpandConstant(ConstantSDNode *CP);
186 
187   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
188   bool ExpandNode(SDNode *Node);
189   void ConvertNodeToLibcall(SDNode *Node);
190   void PromoteNode(SDNode *Node);
191 
192 public:
193   // Node replacement helpers
194 
ReplacedNode(SDNode * N)195   void ReplacedNode(SDNode *N) {
196     LegalizedNodes.erase(N);
197     if (UpdatedNodes)
198       UpdatedNodes->insert(N);
199   }
200 
ReplaceNode(SDNode * Old,SDNode * New)201   void ReplaceNode(SDNode *Old, SDNode *New) {
202     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
203                dbgs() << "     with:      "; New->dump(&DAG));
204 
205     assert(Old->getNumValues() == New->getNumValues() &&
206            "Replacing one node with another that produces a different number "
207            "of values!");
208     DAG.ReplaceAllUsesWith(Old, New);
209     if (UpdatedNodes)
210       UpdatedNodes->insert(New);
211     ReplacedNode(Old);
212   }
213 
ReplaceNode(SDValue Old,SDValue New)214   void ReplaceNode(SDValue Old, SDValue New) {
215     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
216                dbgs() << "     with:      "; New->dump(&DAG));
217 
218     DAG.ReplaceAllUsesWith(Old, New);
219     if (UpdatedNodes)
220       UpdatedNodes->insert(New.getNode());
221     ReplacedNode(Old.getNode());
222   }
223 
ReplaceNode(SDNode * Old,const SDValue * New)224   void ReplaceNode(SDNode *Old, const SDValue *New) {
225     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
226 
227     DAG.ReplaceAllUsesWith(Old, New);
228     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
229       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
230                  New[i]->dump(&DAG));
231       if (UpdatedNodes)
232         UpdatedNodes->insert(New[i].getNode());
233     }
234     ReplacedNode(Old);
235   }
236 };
237 
238 } // end anonymous namespace
239 
240 /// Return a vector shuffle operation which
241 /// performs the same shuffle in terms of order or result bytes, but on a type
242 /// whose vector element type is narrower than the original shuffle type.
243 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
ShuffleWithNarrowerEltType(EVT NVT,EVT VT,const SDLoc & dl,SDValue N1,SDValue N2,ArrayRef<int> Mask) const244 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
245     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
246     ArrayRef<int> Mask) const {
247   unsigned NumMaskElts = VT.getVectorNumElements();
248   unsigned NumDestElts = NVT.getVectorNumElements();
249   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
250 
251   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
252 
253   if (NumEltsGrowth == 1)
254     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
255 
256   SmallVector<int, 8> NewMask;
257   for (unsigned i = 0; i != NumMaskElts; ++i) {
258     int Idx = Mask[i];
259     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
260       if (Idx < 0)
261         NewMask.push_back(-1);
262       else
263         NewMask.push_back(Idx * NumEltsGrowth + j);
264     }
265   }
266   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
267   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
268   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
269 }
270 
271 /// Expands the ConstantFP node to an integer constant or
272 /// a load from the constant pool.
273 SDValue
ExpandConstantFP(ConstantFPSDNode * CFP,bool UseCP)274 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
275   bool Extend = false;
276   SDLoc dl(CFP);
277 
278   // If a FP immediate is precise when represented as a float and if the
279   // target can do an extending load from float to double, we put it into
280   // the constant pool as a float, even if it's is statically typed as a
281   // double.  This shrinks FP constants and canonicalizes them for targets where
282   // an FP extending load is the same cost as a normal load (such as on the x87
283   // fp stack or PPC FP unit).
284   EVT VT = CFP->getValueType(0);
285   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
286   if (!UseCP) {
287     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
288     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
289                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
290   }
291 
292   APFloat APF = CFP->getValueAPF();
293   EVT OrigVT = VT;
294   EVT SVT = VT;
295 
296   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
297   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
298   if (!APF.isSignaling()) {
299     while (SVT != MVT::f32 && SVT != MVT::f16) {
300       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
301       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
302           // Only do this if the target has a native EXTLOAD instruction from
303           // smaller type.
304           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
305           TLI.ShouldShrinkFPConstant(OrigVT)) {
306         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
307         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
308         VT = SVT;
309         Extend = true;
310       }
311     }
312   }
313 
314   SDValue CPIdx =
315       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
316   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
317   if (Extend) {
318     SDValue Result = DAG.getExtLoad(
319         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
320         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
321         Alignment);
322     return Result;
323   }
324   SDValue Result = DAG.getLoad(
325       OrigVT, dl, DAG.getEntryNode(), CPIdx,
326       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
327   return Result;
328 }
329 
330 /// Expands the Constant node to a load from the constant pool.
ExpandConstant(ConstantSDNode * CP)331 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
332   SDLoc dl(CP);
333   EVT VT = CP->getValueType(0);
334   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
335                                       TLI.getPointerTy(DAG.getDataLayout()));
336   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
337   SDValue Result = DAG.getLoad(
338       VT, dl, DAG.getEntryNode(), CPIdx,
339       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
340   return Result;
341 }
342 
343 /// Some target cannot handle a variable insertion index for the
344 /// INSERT_VECTOR_ELT instruction.  In this case, it
345 /// is necessary to spill the vector being inserted into to memory, perform
346 /// the insert there, and then read the result back.
PerformInsertVectorEltInMemory(SDValue Vec,SDValue Val,SDValue Idx,const SDLoc & dl)347 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
348                                                              SDValue Val,
349                                                              SDValue Idx,
350                                                              const SDLoc &dl) {
351   SDValue Tmp1 = Vec;
352   SDValue Tmp2 = Val;
353   SDValue Tmp3 = Idx;
354 
355   // If the target doesn't support this, we have to spill the input vector
356   // to a temporary stack slot, update the element, then reload it.  This is
357   // badness.  We could also load the value into a vector register (either
358   // with a "move to register" or "extload into register" instruction, then
359   // permute it into place, if the idx is a constant and if the idx is
360   // supported by the target.
361   EVT VT    = Tmp1.getValueType();
362   EVT EltVT = VT.getVectorElementType();
363   SDValue StackPtr = DAG.CreateStackTemporary(VT);
364 
365   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
366 
367   // Store the vector.
368   SDValue Ch = DAG.getStore(
369       DAG.getEntryNode(), dl, Tmp1, StackPtr,
370       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
371 
372   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
373 
374   // Store the scalar value.
375   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT);
376   // Load the updated vector.
377   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
378                                                DAG.getMachineFunction(), SPFI));
379 }
380 
ExpandINSERT_VECTOR_ELT(SDValue Vec,SDValue Val,SDValue Idx,const SDLoc & dl)381 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
382                                                       SDValue Idx,
383                                                       const SDLoc &dl) {
384   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
385     // SCALAR_TO_VECTOR requires that the type of the value being inserted
386     // match the element type of the vector being created, except for
387     // integers in which case the inserted value can be over width.
388     EVT EltVT = Vec.getValueType().getVectorElementType();
389     if (Val.getValueType() == EltVT ||
390         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
391       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
392                                   Vec.getValueType(), Val);
393 
394       unsigned NumElts = Vec.getValueType().getVectorNumElements();
395       // We generate a shuffle of InVec and ScVec, so the shuffle mask
396       // should be 0,1,2,3,4,5... with the appropriate element replaced with
397       // elt 0 of the RHS.
398       SmallVector<int, 8> ShufOps;
399       for (unsigned i = 0; i != NumElts; ++i)
400         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
401 
402       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
403     }
404   }
405   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
406 }
407 
OptimizeFloatStore(StoreSDNode * ST)408 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
409   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
410   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
411   // FIXME: We shouldn't do this for TargetConstantFP's.
412   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
413   // to phase ordering between legalized code and the dag combiner.  This
414   // probably means that we need to integrate dag combiner and legalizer
415   // together.
416   // We generally can't do this one for long doubles.
417   SDValue Chain = ST->getChain();
418   SDValue Ptr = ST->getBasePtr();
419   unsigned Alignment = ST->getAlignment();
420   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
421   AAMDNodes AAInfo = ST->getAAInfo();
422   SDLoc dl(ST);
423   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
424     if (CFP->getValueType(0) == MVT::f32 &&
425         TLI.isTypeLegal(MVT::i32)) {
426       SDValue Con = DAG.getConstant(CFP->getValueAPF().
427                                       bitcastToAPInt().zextOrTrunc(32),
428                                     SDLoc(CFP), MVT::i32);
429       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(), Alignment,
430                           MMOFlags, AAInfo);
431     }
432 
433     if (CFP->getValueType(0) == MVT::f64) {
434       // If this target supports 64-bit registers, do a single 64-bit store.
435       if (TLI.isTypeLegal(MVT::i64)) {
436         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
437                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
438         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
439                             Alignment, MMOFlags, AAInfo);
440       }
441 
442       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
443         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
444         // stores.  If the target supports neither 32- nor 64-bits, this
445         // xform is certainly not worth it.
446         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
447         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
448         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
449         if (DAG.getDataLayout().isBigEndian())
450           std::swap(Lo, Hi);
451 
452         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), Alignment,
453                           MMOFlags, AAInfo);
454         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
455                           DAG.getConstant(4, dl, Ptr.getValueType()));
456         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
457                           ST->getPointerInfo().getWithOffset(4),
458                           MinAlign(Alignment, 4U), MMOFlags, AAInfo);
459 
460         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
461       }
462     }
463   }
464   return SDValue(nullptr, 0);
465 }
466 
LegalizeStoreOps(SDNode * Node)467 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
468   StoreSDNode *ST = cast<StoreSDNode>(Node);
469   SDValue Chain = ST->getChain();
470   SDValue Ptr = ST->getBasePtr();
471   SDLoc dl(Node);
472 
473   unsigned Alignment = ST->getAlignment();
474   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
475   AAMDNodes AAInfo = ST->getAAInfo();
476 
477   if (!ST->isTruncatingStore()) {
478     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
479     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
480       ReplaceNode(ST, OptStore);
481       return;
482     }
483 
484     SDValue Value = ST->getValue();
485     MVT VT = Value.getSimpleValueType();
486     switch (TLI.getOperationAction(ISD::STORE, VT)) {
487     default: llvm_unreachable("This action is not supported yet!");
488     case TargetLowering::Legal: {
489       // If this is an unaligned store and the target doesn't support it,
490       // expand it.
491       EVT MemVT = ST->getMemoryVT();
492       unsigned AS = ST->getAddressSpace();
493       unsigned Align = ST->getAlignment();
494       const DataLayout &DL = DAG.getDataLayout();
495       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
496         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
497         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
498         ReplaceNode(SDValue(ST, 0), Result);
499       } else
500         LLVM_DEBUG(dbgs() << "Legal store\n");
501       break;
502     }
503     case TargetLowering::Custom: {
504       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
505       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
506       if (Res && Res != SDValue(Node, 0))
507         ReplaceNode(SDValue(Node, 0), Res);
508       return;
509     }
510     case TargetLowering::Promote: {
511       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
512       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
513              "Can only promote stores to same size type");
514       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
515       SDValue Result =
516           DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
517                        Alignment, MMOFlags, AAInfo);
518       ReplaceNode(SDValue(Node, 0), Result);
519       break;
520     }
521     }
522     return;
523   }
524 
525   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
526   SDValue Value = ST->getValue();
527   EVT StVT = ST->getMemoryVT();
528   unsigned StWidth = StVT.getSizeInBits();
529   auto &DL = DAG.getDataLayout();
530 
531   if (StWidth != StVT.getStoreSizeInBits()) {
532     // Promote to a byte-sized store with upper bits zero if not
533     // storing an integral number of bytes.  For example, promote
534     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
535     EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
536                                 StVT.getStoreSizeInBits());
537     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
538     SDValue Result =
539         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
540                           Alignment, MMOFlags, AAInfo);
541     ReplaceNode(SDValue(Node, 0), Result);
542   } else if (StWidth & (StWidth - 1)) {
543     // If not storing a power-of-2 number of bits, expand as two stores.
544     assert(!StVT.isVector() && "Unsupported truncstore!");
545     unsigned RoundWidth = 1 << Log2_32(StWidth);
546     assert(RoundWidth < StWidth);
547     unsigned ExtraWidth = StWidth - RoundWidth;
548     assert(ExtraWidth < RoundWidth);
549     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
550            "Store size not an integral number of bytes!");
551     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
552     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
553     SDValue Lo, Hi;
554     unsigned IncrementSize;
555 
556     if (DL.isLittleEndian()) {
557       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
558       // Store the bottom RoundWidth bits.
559       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
560                              RoundVT, Alignment, MMOFlags, AAInfo);
561 
562       // Store the remaining ExtraWidth bits.
563       IncrementSize = RoundWidth / 8;
564       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
565                         DAG.getConstant(IncrementSize, dl,
566                                         Ptr.getValueType()));
567       Hi = DAG.getNode(
568           ISD::SRL, dl, Value.getValueType(), Value,
569           DAG.getConstant(RoundWidth, dl,
570                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
571       Hi = DAG.getTruncStore(
572           Chain, dl, Hi, Ptr,
573           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
574           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
575     } else {
576       // Big endian - avoid unaligned stores.
577       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
578       // Store the top RoundWidth bits.
579       Hi = DAG.getNode(
580           ISD::SRL, dl, Value.getValueType(), Value,
581           DAG.getConstant(ExtraWidth, dl,
582                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
583       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
584                              RoundVT, Alignment, MMOFlags, AAInfo);
585 
586       // Store the remaining ExtraWidth bits.
587       IncrementSize = RoundWidth / 8;
588       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
589                         DAG.getConstant(IncrementSize, dl,
590                                         Ptr.getValueType()));
591       Lo = DAG.getTruncStore(
592           Chain, dl, Value, Ptr,
593           ST->getPointerInfo().getWithOffset(IncrementSize), ExtraVT,
594           MinAlign(Alignment, IncrementSize), MMOFlags, AAInfo);
595     }
596 
597     // The order of the stores doesn't matter.
598     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
599     ReplaceNode(SDValue(Node, 0), Result);
600   } else {
601     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
602     default: llvm_unreachable("This action is not supported yet!");
603     case TargetLowering::Legal: {
604       EVT MemVT = ST->getMemoryVT();
605       unsigned AS = ST->getAddressSpace();
606       unsigned Align = ST->getAlignment();
607       // If this is an unaligned store and the target doesn't support it,
608       // expand it.
609       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
610         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
611         ReplaceNode(SDValue(ST, 0), Result);
612       }
613       break;
614     }
615     case TargetLowering::Custom: {
616       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
617       if (Res && Res != SDValue(Node, 0))
618         ReplaceNode(SDValue(Node, 0), Res);
619       return;
620     }
621     case TargetLowering::Expand:
622       assert(!StVT.isVector() &&
623              "Vector Stores are handled in LegalizeVectorOps");
624 
625       SDValue Result;
626 
627       // TRUNCSTORE:i16 i32 -> STORE i16
628       if (TLI.isTypeLegal(StVT)) {
629         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
630         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
631                               Alignment, MMOFlags, AAInfo);
632       } else {
633         // The in-memory type isn't legal. Truncate to the type it would promote
634         // to, and then do a truncstore.
635         Value = DAG.getNode(ISD::TRUNCATE, dl,
636                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
637                             Value);
638         Result = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
639                                    StVT, Alignment, MMOFlags, AAInfo);
640       }
641 
642       ReplaceNode(SDValue(Node, 0), Result);
643       break;
644     }
645   }
646 }
647 
LegalizeLoadOps(SDNode * Node)648 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
649   LoadSDNode *LD = cast<LoadSDNode>(Node);
650   SDValue Chain = LD->getChain();  // The chain.
651   SDValue Ptr = LD->getBasePtr();  // The base pointer.
652   SDValue Value;                   // The value returned by the load op.
653   SDLoc dl(Node);
654 
655   ISD::LoadExtType ExtType = LD->getExtensionType();
656   if (ExtType == ISD::NON_EXTLOAD) {
657     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
658     MVT VT = Node->getSimpleValueType(0);
659     SDValue RVal = SDValue(Node, 0);
660     SDValue RChain = SDValue(Node, 1);
661 
662     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
663     default: llvm_unreachable("This action is not supported yet!");
664     case TargetLowering::Legal: {
665       EVT MemVT = LD->getMemoryVT();
666       unsigned AS = LD->getAddressSpace();
667       unsigned Align = LD->getAlignment();
668       const DataLayout &DL = DAG.getDataLayout();
669       // If this is an unaligned load and the target doesn't support it,
670       // expand it.
671       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
672         std::tie(RVal, RChain) =  TLI.expandUnalignedLoad(LD, DAG);
673       }
674       break;
675     }
676     case TargetLowering::Custom:
677       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
678         RVal = Res;
679         RChain = Res.getValue(1);
680       }
681       break;
682 
683     case TargetLowering::Promote: {
684       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
685       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
686              "Can only promote loads to same size type");
687 
688       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
689       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
690       RChain = Res.getValue(1);
691       break;
692     }
693     }
694     if (RChain.getNode() != Node) {
695       assert(RVal.getNode() != Node && "Load must be completely replaced");
696       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
697       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
698       if (UpdatedNodes) {
699         UpdatedNodes->insert(RVal.getNode());
700         UpdatedNodes->insert(RChain.getNode());
701       }
702       ReplacedNode(Node);
703     }
704     return;
705   }
706 
707   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
708   EVT SrcVT = LD->getMemoryVT();
709   unsigned SrcWidth = SrcVT.getSizeInBits();
710   unsigned Alignment = LD->getAlignment();
711   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
712   AAMDNodes AAInfo = LD->getAAInfo();
713 
714   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
715       // Some targets pretend to have an i1 loading operation, and actually
716       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
717       // bits are guaranteed to be zero; it helps the optimizers understand
718       // that these bits are zero.  It is also useful for EXTLOAD, since it
719       // tells the optimizers that those bits are undefined.  It would be
720       // nice to have an effective generic way of getting these benefits...
721       // Until such a way is found, don't insist on promoting i1 here.
722       (SrcVT != MVT::i1 ||
723        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
724          TargetLowering::Promote)) {
725     // Promote to a byte-sized load if not loading an integral number of
726     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
727     unsigned NewWidth = SrcVT.getStoreSizeInBits();
728     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
729     SDValue Ch;
730 
731     // The extra bits are guaranteed to be zero, since we stored them that
732     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
733 
734     ISD::LoadExtType NewExtType =
735       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
736 
737     SDValue Result =
738         DAG.getExtLoad(NewExtType, dl, Node->getValueType(0), Chain, Ptr,
739                        LD->getPointerInfo(), NVT, Alignment, MMOFlags, AAInfo);
740 
741     Ch = Result.getValue(1); // The chain.
742 
743     if (ExtType == ISD::SEXTLOAD)
744       // Having the top bits zero doesn't help when sign extending.
745       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
746                            Result.getValueType(),
747                            Result, DAG.getValueType(SrcVT));
748     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
749       // All the top bits are guaranteed to be zero - inform the optimizers.
750       Result = DAG.getNode(ISD::AssertZext, dl,
751                            Result.getValueType(), Result,
752                            DAG.getValueType(SrcVT));
753 
754     Value = Result;
755     Chain = Ch;
756   } else if (SrcWidth & (SrcWidth - 1)) {
757     // If not loading a power-of-2 number of bits, expand as two loads.
758     assert(!SrcVT.isVector() && "Unsupported extload!");
759     unsigned RoundWidth = 1 << Log2_32(SrcWidth);
760     assert(RoundWidth < SrcWidth);
761     unsigned ExtraWidth = SrcWidth - RoundWidth;
762     assert(ExtraWidth < RoundWidth);
763     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
764            "Load size not an integral number of bytes!");
765     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
766     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
767     SDValue Lo, Hi, Ch;
768     unsigned IncrementSize;
769     auto &DL = DAG.getDataLayout();
770 
771     if (DL.isLittleEndian()) {
772       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
773       // Load the bottom RoundWidth bits.
774       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
775                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
776                           AAInfo);
777 
778       // Load the remaining ExtraWidth bits.
779       IncrementSize = RoundWidth / 8;
780       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
781                          DAG.getConstant(IncrementSize, dl,
782                                          Ptr.getValueType()));
783       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
784                           LD->getPointerInfo().getWithOffset(IncrementSize),
785                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
786                           AAInfo);
787 
788       // Build a factor node to remember that this load is independent of
789       // the other one.
790       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
791                        Hi.getValue(1));
792 
793       // Move the top bits to the right place.
794       Hi = DAG.getNode(
795           ISD::SHL, dl, Hi.getValueType(), Hi,
796           DAG.getConstant(RoundWidth, dl,
797                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
798 
799       // Join the hi and lo parts.
800       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
801     } else {
802       // Big endian - avoid unaligned loads.
803       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
804       // Load the top RoundWidth bits.
805       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
806                           LD->getPointerInfo(), RoundVT, Alignment, MMOFlags,
807                           AAInfo);
808 
809       // Load the remaining ExtraWidth bits.
810       IncrementSize = RoundWidth / 8;
811       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
812                          DAG.getConstant(IncrementSize, dl,
813                                          Ptr.getValueType()));
814       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
815                           LD->getPointerInfo().getWithOffset(IncrementSize),
816                           ExtraVT, MinAlign(Alignment, IncrementSize), MMOFlags,
817                           AAInfo);
818 
819       // Build a factor node to remember that this load is independent of
820       // the other one.
821       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
822                        Hi.getValue(1));
823 
824       // Move the top bits to the right place.
825       Hi = DAG.getNode(
826           ISD::SHL, dl, Hi.getValueType(), Hi,
827           DAG.getConstant(ExtraWidth, dl,
828                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
829 
830       // Join the hi and lo parts.
831       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
832     }
833 
834     Chain = Ch;
835   } else {
836     bool isCustom = false;
837     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
838                                  SrcVT.getSimpleVT())) {
839     default: llvm_unreachable("This action is not supported yet!");
840     case TargetLowering::Custom:
841       isCustom = true;
842       LLVM_FALLTHROUGH;
843     case TargetLowering::Legal:
844       Value = SDValue(Node, 0);
845       Chain = SDValue(Node, 1);
846 
847       if (isCustom) {
848         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
849           Value = Res;
850           Chain = Res.getValue(1);
851         }
852       } else {
853         // If this is an unaligned load and the target doesn't support it,
854         // expand it.
855         EVT MemVT = LD->getMemoryVT();
856         unsigned AS = LD->getAddressSpace();
857         unsigned Align = LD->getAlignment();
858         const DataLayout &DL = DAG.getDataLayout();
859         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
860           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
861         }
862       }
863       break;
864 
865     case TargetLowering::Expand: {
866       EVT DestVT = Node->getValueType(0);
867       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
868         // If the source type is not legal, see if there is a legal extload to
869         // an intermediate type that we can then extend further.
870         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
871         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
872             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
873           // If we are loading a legal type, this is a non-extload followed by a
874           // full extend.
875           ISD::LoadExtType MidExtType =
876               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
877 
878           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
879                                         SrcVT, LD->getMemOperand());
880           unsigned ExtendOp =
881               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
882           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
883           Chain = Load.getValue(1);
884           break;
885         }
886 
887         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
888         // normal undefined upper bits behavior to allow using an in-reg extend
889         // with the illegal FP type, so load as an integer and do the
890         // from-integer conversion.
891         if (SrcVT.getScalarType() == MVT::f16) {
892           EVT ISrcVT = SrcVT.changeTypeToInteger();
893           EVT IDestVT = DestVT.changeTypeToInteger();
894           EVT LoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
895 
896           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, LoadVT,
897                                           Chain, Ptr, ISrcVT,
898                                           LD->getMemOperand());
899           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
900           Chain = Result.getValue(1);
901           break;
902         }
903       }
904 
905       assert(!SrcVT.isVector() &&
906              "Vector Loads are handled in LegalizeVectorOps");
907 
908       // FIXME: This does not work for vectors on most targets.  Sign-
909       // and zero-extend operations are currently folded into extending
910       // loads, whether they are legal or not, and then we end up here
911       // without any support for legalizing them.
912       assert(ExtType != ISD::EXTLOAD &&
913              "EXTLOAD should always be supported!");
914       // Turn the unsupported load into an EXTLOAD followed by an
915       // explicit zero/sign extend inreg.
916       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
917                                       Node->getValueType(0),
918                                       Chain, Ptr, SrcVT,
919                                       LD->getMemOperand());
920       SDValue ValRes;
921       if (ExtType == ISD::SEXTLOAD)
922         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
923                              Result.getValueType(),
924                              Result, DAG.getValueType(SrcVT));
925       else
926         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
927       Value = ValRes;
928       Chain = Result.getValue(1);
929       break;
930     }
931     }
932   }
933 
934   // Since loads produce two values, make sure to remember that we legalized
935   // both of them.
936   if (Chain.getNode() != Node) {
937     assert(Value.getNode() != Node && "Load must be completely replaced");
938     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
939     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
940     if (UpdatedNodes) {
941       UpdatedNodes->insert(Value.getNode());
942       UpdatedNodes->insert(Chain.getNode());
943     }
944     ReplacedNode(Node);
945   }
946 }
947 
948 /// Return a legal replacement for the given operation, with all legal operands.
LegalizeOp(SDNode * Node)949 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
950   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
951 
952   // Allow illegal target nodes and illegal registers.
953   if (Node->getOpcode() == ISD::TargetConstant ||
954       Node->getOpcode() == ISD::Register)
955     return;
956 
957 #ifndef NDEBUG
958   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
959     assert((TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
960               TargetLowering::TypeLegal ||
961             TLI.isTypeLegal(Node->getValueType(i))) &&
962            "Unexpected illegal type!");
963 
964   for (const SDValue &Op : Node->op_values())
965     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
966               TargetLowering::TypeLegal ||
967             TLI.isTypeLegal(Op.getValueType()) ||
968             Op.getOpcode() == ISD::TargetConstant ||
969             Op.getOpcode() == ISD::Register) &&
970             "Unexpected illegal type!");
971 #endif
972 
973   // Figure out the correct action; the way to query this varies by opcode
974   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
975   bool SimpleFinishLegalizing = true;
976   switch (Node->getOpcode()) {
977   case ISD::INTRINSIC_W_CHAIN:
978   case ISD::INTRINSIC_WO_CHAIN:
979   case ISD::INTRINSIC_VOID:
980   case ISD::STACKSAVE:
981     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
982     break;
983   case ISD::GET_DYNAMIC_AREA_OFFSET:
984     Action = TLI.getOperationAction(Node->getOpcode(),
985                                     Node->getValueType(0));
986     break;
987   case ISD::VAARG:
988     Action = TLI.getOperationAction(Node->getOpcode(),
989                                     Node->getValueType(0));
990     if (Action != TargetLowering::Promote)
991       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
992     break;
993   case ISD::FP_TO_FP16:
994   case ISD::SINT_TO_FP:
995   case ISD::UINT_TO_FP:
996   case ISD::EXTRACT_VECTOR_ELT:
997     Action = TLI.getOperationAction(Node->getOpcode(),
998                                     Node->getOperand(0).getValueType());
999     break;
1000   case ISD::FP_ROUND_INREG:
1001   case ISD::SIGN_EXTEND_INREG: {
1002     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1003     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1004     break;
1005   }
1006   case ISD::ATOMIC_STORE:
1007     Action = TLI.getOperationAction(Node->getOpcode(),
1008                                     Node->getOperand(2).getValueType());
1009     break;
1010   case ISD::SELECT_CC:
1011   case ISD::SETCC:
1012   case ISD::BR_CC: {
1013     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1014                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1015     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
1016     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1017     ISD::CondCode CCCode =
1018         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1019     Action = TLI.getCondCodeAction(CCCode, OpVT);
1020     if (Action == TargetLowering::Legal) {
1021       if (Node->getOpcode() == ISD::SELECT_CC)
1022         Action = TLI.getOperationAction(Node->getOpcode(),
1023                                         Node->getValueType(0));
1024       else
1025         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1026     }
1027     break;
1028   }
1029   case ISD::LOAD:
1030   case ISD::STORE:
1031     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1032     // STORE expects the unlegalized operand in some cases.
1033     SimpleFinishLegalizing = false;
1034     break;
1035   case ISD::CALLSEQ_START:
1036   case ISD::CALLSEQ_END:
1037     // FIXME: This shouldn't be necessary.  These nodes have special properties
1038     // dealing with the recursive nature of legalization.  Removing this
1039     // special case should be done as part of making LegalizeDAG non-recursive.
1040     SimpleFinishLegalizing = false;
1041     break;
1042   case ISD::EXTRACT_ELEMENT:
1043   case ISD::FLT_ROUNDS_:
1044   case ISD::MERGE_VALUES:
1045   case ISD::EH_RETURN:
1046   case ISD::FRAME_TO_ARGS_OFFSET:
1047   case ISD::EH_DWARF_CFA:
1048   case ISD::EH_SJLJ_SETJMP:
1049   case ISD::EH_SJLJ_LONGJMP:
1050   case ISD::EH_SJLJ_SETUP_DISPATCH:
1051     // These operations lie about being legal: when they claim to be legal,
1052     // they should actually be expanded.
1053     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1054     if (Action == TargetLowering::Legal)
1055       Action = TargetLowering::Expand;
1056     break;
1057   case ISD::INIT_TRAMPOLINE:
1058   case ISD::ADJUST_TRAMPOLINE:
1059   case ISD::FRAMEADDR:
1060   case ISD::RETURNADDR:
1061   case ISD::ADDROFRETURNADDR:
1062   case ISD::SPONENTRY:
1063     // These operations lie about being legal: when they claim to be legal,
1064     // they should actually be custom-lowered.
1065     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1066     if (Action == TargetLowering::Legal)
1067       Action = TargetLowering::Custom;
1068     break;
1069   case ISD::READCYCLECOUNTER:
1070     // READCYCLECOUNTER returns an i64, even if type legalization might have
1071     // expanded that to several smaller types.
1072     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1073     break;
1074   case ISD::READ_REGISTER:
1075   case ISD::WRITE_REGISTER:
1076     // Named register is legal in the DAG, but blocked by register name
1077     // selection if not implemented by target (to chose the correct register)
1078     // They'll be converted to Copy(To/From)Reg.
1079     Action = TargetLowering::Legal;
1080     break;
1081   case ISD::DEBUGTRAP:
1082     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1083     if (Action == TargetLowering::Expand) {
1084       // replace ISD::DEBUGTRAP with ISD::TRAP
1085       SDValue NewVal;
1086       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1087                            Node->getOperand(0));
1088       ReplaceNode(Node, NewVal.getNode());
1089       LegalizeOp(NewVal.getNode());
1090       return;
1091     }
1092     break;
1093   case ISD::STRICT_FADD:
1094   case ISD::STRICT_FSUB:
1095   case ISD::STRICT_FMUL:
1096   case ISD::STRICT_FDIV:
1097   case ISD::STRICT_FREM:
1098   case ISD::STRICT_FSQRT:
1099   case ISD::STRICT_FMA:
1100   case ISD::STRICT_FPOW:
1101   case ISD::STRICT_FPOWI:
1102   case ISD::STRICT_FSIN:
1103   case ISD::STRICT_FCOS:
1104   case ISD::STRICT_FEXP:
1105   case ISD::STRICT_FEXP2:
1106   case ISD::STRICT_FLOG:
1107   case ISD::STRICT_FLOG10:
1108   case ISD::STRICT_FLOG2:
1109   case ISD::STRICT_FRINT:
1110   case ISD::STRICT_FNEARBYINT:
1111   case ISD::STRICT_FMAXNUM:
1112   case ISD::STRICT_FMINNUM:
1113   case ISD::STRICT_FCEIL:
1114   case ISD::STRICT_FFLOOR:
1115   case ISD::STRICT_FROUND:
1116   case ISD::STRICT_FTRUNC:
1117     // These pseudo-ops get legalized as if they were their non-strict
1118     // equivalent.  For instance, if ISD::FSQRT is legal then ISD::STRICT_FSQRT
1119     // is also legal, but if ISD::FSQRT requires expansion then so does
1120     // ISD::STRICT_FSQRT.
1121     Action = TLI.getStrictFPOperationAction(Node->getOpcode(),
1122                                             Node->getValueType(0));
1123     break;
1124   case ISD::SADDSAT:
1125   case ISD::UADDSAT:
1126   case ISD::SSUBSAT:
1127   case ISD::USUBSAT: {
1128     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1129     break;
1130   }
1131   case ISD::SMULFIX: {
1132     unsigned Scale = Node->getConstantOperandVal(2);
1133     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1134                                               Node->getValueType(0), Scale);
1135     break;
1136   }
1137   case ISD::MSCATTER:
1138     Action = TLI.getOperationAction(Node->getOpcode(),
1139                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1140     break;
1141   case ISD::MSTORE:
1142     Action = TLI.getOperationAction(Node->getOpcode(),
1143                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1144     break;
1145   default:
1146     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1147       Action = TargetLowering::Legal;
1148     } else {
1149       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1150     }
1151     break;
1152   }
1153 
1154   if (SimpleFinishLegalizing) {
1155     SDNode *NewNode = Node;
1156     switch (Node->getOpcode()) {
1157     default: break;
1158     case ISD::SHL:
1159     case ISD::SRL:
1160     case ISD::SRA:
1161     case ISD::ROTL:
1162     case ISD::ROTR: {
1163       // Legalizing shifts/rotates requires adjusting the shift amount
1164       // to the appropriate width.
1165       SDValue Op0 = Node->getOperand(0);
1166       SDValue Op1 = Node->getOperand(1);
1167       if (!Op1.getValueType().isVector()) {
1168         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1169         // The getShiftAmountOperand() may create a new operand node or
1170         // return the existing one. If new operand is created we need
1171         // to update the parent node.
1172         // Do not try to legalize SAO here! It will be automatically legalized
1173         // in the next round.
1174         if (SAO != Op1)
1175           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1176       }
1177     }
1178     break;
1179     case ISD::FSHL:
1180     case ISD::FSHR:
1181     case ISD::SRL_PARTS:
1182     case ISD::SRA_PARTS:
1183     case ISD::SHL_PARTS: {
1184       // Legalizing shifts/rotates requires adjusting the shift amount
1185       // to the appropriate width.
1186       SDValue Op0 = Node->getOperand(0);
1187       SDValue Op1 = Node->getOperand(1);
1188       SDValue Op2 = Node->getOperand(2);
1189       if (!Op2.getValueType().isVector()) {
1190         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1191         // The getShiftAmountOperand() may create a new operand node or
1192         // return the existing one. If new operand is created we need
1193         // to update the parent node.
1194         if (SAO != Op2)
1195           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1196       }
1197       break;
1198     }
1199     }
1200 
1201     if (NewNode != Node) {
1202       ReplaceNode(Node, NewNode);
1203       Node = NewNode;
1204     }
1205     switch (Action) {
1206     case TargetLowering::Legal:
1207       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1208       return;
1209     case TargetLowering::Custom:
1210       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1211       // FIXME: The handling for custom lowering with multiple results is
1212       // a complete mess.
1213       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1214         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1215           return;
1216 
1217         if (Node->getNumValues() == 1) {
1218           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1219           // We can just directly replace this node with the lowered value.
1220           ReplaceNode(SDValue(Node, 0), Res);
1221           return;
1222         }
1223 
1224         SmallVector<SDValue, 8> ResultVals;
1225         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1226           ResultVals.push_back(Res.getValue(i));
1227         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1228         ReplaceNode(Node, ResultVals.data());
1229         return;
1230       }
1231       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1232       LLVM_FALLTHROUGH;
1233     case TargetLowering::Expand:
1234       if (ExpandNode(Node))
1235         return;
1236       LLVM_FALLTHROUGH;
1237     case TargetLowering::LibCall:
1238       ConvertNodeToLibcall(Node);
1239       return;
1240     case TargetLowering::Promote:
1241       PromoteNode(Node);
1242       return;
1243     }
1244   }
1245 
1246   switch (Node->getOpcode()) {
1247   default:
1248 #ifndef NDEBUG
1249     dbgs() << "NODE: ";
1250     Node->dump( &DAG);
1251     dbgs() << "\n";
1252 #endif
1253     llvm_unreachable("Do not know how to legalize this operator!");
1254 
1255   case ISD::CALLSEQ_START:
1256   case ISD::CALLSEQ_END:
1257     break;
1258   case ISD::LOAD:
1259     return LegalizeLoadOps(Node);
1260   case ISD::STORE:
1261     return LegalizeStoreOps(Node);
1262   }
1263 }
1264 
ExpandExtractFromVectorThroughStack(SDValue Op)1265 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1266   SDValue Vec = Op.getOperand(0);
1267   SDValue Idx = Op.getOperand(1);
1268   SDLoc dl(Op);
1269 
1270   // Before we generate a new store to a temporary stack slot, see if there is
1271   // already one that we can use. There often is because when we scalarize
1272   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1273   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1274   // the vector. If all are expanded here, we don't want one store per vector
1275   // element.
1276 
1277   // Caches for hasPredecessorHelper
1278   SmallPtrSet<const SDNode *, 32> Visited;
1279   SmallVector<const SDNode *, 16> Worklist;
1280   Visited.insert(Op.getNode());
1281   Worklist.push_back(Idx.getNode());
1282   SDValue StackPtr, Ch;
1283   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1284        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1285     SDNode *User = *UI;
1286     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1287       if (ST->isIndexed() || ST->isTruncatingStore() ||
1288           ST->getValue() != Vec)
1289         continue;
1290 
1291       // Make sure that nothing else could have stored into the destination of
1292       // this store.
1293       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1294         continue;
1295 
1296       // If the index is dependent on the store we will introduce a cycle when
1297       // creating the load (the load uses the index, and by replacing the chain
1298       // we will make the index dependent on the load). Also, the store might be
1299       // dependent on the extractelement and introduce a cycle when creating
1300       // the load.
1301       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1302           ST->hasPredecessor(Op.getNode()))
1303         continue;
1304 
1305       StackPtr = ST->getBasePtr();
1306       Ch = SDValue(ST, 0);
1307       break;
1308     }
1309   }
1310 
1311   EVT VecVT = Vec.getValueType();
1312 
1313   if (!Ch.getNode()) {
1314     // Store the value to a temporary stack slot, then LOAD the returned part.
1315     StackPtr = DAG.CreateStackTemporary(VecVT);
1316     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1317                       MachinePointerInfo());
1318   }
1319 
1320   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1321 
1322   SDValue NewLoad;
1323 
1324   if (Op.getValueType().isVector())
1325     NewLoad =
1326         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1327   else
1328     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1329                              MachinePointerInfo(),
1330                              VecVT.getVectorElementType());
1331 
1332   // Replace the chain going out of the store, by the one out of the load.
1333   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1334 
1335   // We introduced a cycle though, so update the loads operands, making sure
1336   // to use the original store's chain as an incoming chain.
1337   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1338                                           NewLoad->op_end());
1339   NewLoadOperands[0] = Ch;
1340   NewLoad =
1341       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1342   return NewLoad;
1343 }
1344 
ExpandInsertToVectorThroughStack(SDValue Op)1345 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1346   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1347 
1348   SDValue Vec  = Op.getOperand(0);
1349   SDValue Part = Op.getOperand(1);
1350   SDValue Idx  = Op.getOperand(2);
1351   SDLoc dl(Op);
1352 
1353   // Store the value to a temporary stack slot, then LOAD the returned part.
1354   EVT VecVT = Vec.getValueType();
1355   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1356   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1357   MachinePointerInfo PtrInfo =
1358       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1359 
1360   // First store the whole vector.
1361   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1362 
1363   // Then store the inserted part.
1364   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1365 
1366   // Store the subvector.
1367   Ch = DAG.getStore(Ch, dl, Part, SubStackPtr, MachinePointerInfo());
1368 
1369   // Finally, load the updated vector.
1370   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1371 }
1372 
ExpandVectorBuildThroughStack(SDNode * Node)1373 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1374   // We can't handle this case efficiently.  Allocate a sufficiently
1375   // aligned object on the stack, store each element into it, then load
1376   // the result as a vector.
1377   // Create the stack frame object.
1378   EVT VT = Node->getValueType(0);
1379   EVT EltVT = VT.getVectorElementType();
1380   SDLoc dl(Node);
1381   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1382   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1383   MachinePointerInfo PtrInfo =
1384       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1385 
1386   // Emit a store of each element to the stack slot.
1387   SmallVector<SDValue, 8> Stores;
1388   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
1389   // Store (in the right endianness) the elements to memory.
1390   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1391     // Ignore undef elements.
1392     if (Node->getOperand(i).isUndef()) continue;
1393 
1394     unsigned Offset = TypeByteSize*i;
1395 
1396     SDValue Idx = DAG.getConstant(Offset, dl, FIPtr.getValueType());
1397     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
1398 
1399     // If the destination vector element type is narrower than the source
1400     // element type, only store the bits necessary.
1401     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
1402       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1403                                          Node->getOperand(i), Idx,
1404                                          PtrInfo.getWithOffset(Offset), EltVT));
1405     } else
1406       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1407                                     Idx, PtrInfo.getWithOffset(Offset)));
1408   }
1409 
1410   SDValue StoreChain;
1411   if (!Stores.empty())    // Not all undef elements?
1412     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1413   else
1414     StoreChain = DAG.getEntryNode();
1415 
1416   // Result is a load from the stack slot.
1417   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1418 }
1419 
1420 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1421 /// containing the sign bit if the target has no integer value capable of
1422 /// holding all bits of the floating-point value.
getSignAsIntValue(FloatSignAsInt & State,const SDLoc & DL,SDValue Value) const1423 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1424                                              const SDLoc &DL,
1425                                              SDValue Value) const {
1426   EVT FloatVT = Value.getValueType();
1427   unsigned NumBits = FloatVT.getSizeInBits();
1428   State.FloatVT = FloatVT;
1429   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1430   // Convert to an integer of the same size.
1431   if (TLI.isTypeLegal(IVT)) {
1432     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1433     State.SignMask = APInt::getSignMask(NumBits);
1434     State.SignBit = NumBits - 1;
1435     return;
1436   }
1437 
1438   auto &DataLayout = DAG.getDataLayout();
1439   // Store the float to memory, then load the sign part out as an integer.
1440   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1441   // First create a temporary that is aligned for both the load and store.
1442   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1443   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1444   // Then store the float to it.
1445   State.FloatPtr = StackPtr;
1446   MachineFunction &MF = DAG.getMachineFunction();
1447   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1448   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1449                              State.FloatPointerInfo);
1450 
1451   SDValue IntPtr;
1452   if (DataLayout.isBigEndian()) {
1453     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1454     // Load out a legal integer with the same sign bit as the float.
1455     IntPtr = StackPtr;
1456     State.IntPointerInfo = State.FloatPointerInfo;
1457   } else {
1458     // Advance the pointer so that the loaded byte will contain the sign bit.
1459     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1460     IntPtr = DAG.getNode(ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
1461                       DAG.getConstant(ByteOffset, DL, StackPtr.getValueType()));
1462     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1463                                                              ByteOffset);
1464   }
1465 
1466   State.IntPtr = IntPtr;
1467   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1468                                   State.IntPointerInfo, MVT::i8);
1469   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1470   State.SignBit = 7;
1471 }
1472 
1473 /// Replace the integer value produced by getSignAsIntValue() with a new value
1474 /// and cast the result back to a floating-point type.
modifySignAsInt(const FloatSignAsInt & State,const SDLoc & DL,SDValue NewIntValue) const1475 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1476                                               const SDLoc &DL,
1477                                               SDValue NewIntValue) const {
1478   if (!State.Chain)
1479     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1480 
1481   // Override the part containing the sign bit in the value stored on the stack.
1482   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1483                                     State.IntPointerInfo, MVT::i8);
1484   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1485                      State.FloatPointerInfo);
1486 }
1487 
ExpandFCOPYSIGN(SDNode * Node) const1488 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1489   SDLoc DL(Node);
1490   SDValue Mag = Node->getOperand(0);
1491   SDValue Sign = Node->getOperand(1);
1492 
1493   // Get sign bit into an integer value.
1494   FloatSignAsInt SignAsInt;
1495   getSignAsIntValue(SignAsInt, DL, Sign);
1496 
1497   EVT IntVT = SignAsInt.IntValue.getValueType();
1498   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1499   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1500                                 SignMask);
1501 
1502   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1503   EVT FloatVT = Mag.getValueType();
1504   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1505       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1506     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1507     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1508     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1509                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1510     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1511   }
1512 
1513   // Transform Mag value to integer, and clear the sign bit.
1514   FloatSignAsInt MagAsInt;
1515   getSignAsIntValue(MagAsInt, DL, Mag);
1516   EVT MagVT = MagAsInt.IntValue.getValueType();
1517   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1518   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1519                                     ClearSignMask);
1520 
1521   // Get the signbit at the right position for MagAsInt.
1522   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1523   EVT ShiftVT = IntVT;
1524   if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1525     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1526     ShiftVT = MagVT;
1527   }
1528   if (ShiftAmount > 0) {
1529     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1530     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1531   } else if (ShiftAmount < 0) {
1532     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1533     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1534   }
1535   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1536     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1537   }
1538 
1539   // Store the part with the modified sign and convert back to float.
1540   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1541   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1542 }
1543 
ExpandFABS(SDNode * Node) const1544 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1545   SDLoc DL(Node);
1546   SDValue Value = Node->getOperand(0);
1547 
1548   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1549   EVT FloatVT = Value.getValueType();
1550   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1551     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1552     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1553   }
1554 
1555   // Transform value to integer, clear the sign bit and transform back.
1556   FloatSignAsInt ValueAsInt;
1557   getSignAsIntValue(ValueAsInt, DL, Value);
1558   EVT IntVT = ValueAsInt.IntValue.getValueType();
1559   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1560   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1561                                     ClearSignMask);
1562   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1563 }
1564 
ExpandDYNAMIC_STACKALLOC(SDNode * Node,SmallVectorImpl<SDValue> & Results)1565 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1566                                            SmallVectorImpl<SDValue> &Results) {
1567   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1568   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1569           " not tell us which reg is the stack pointer!");
1570   SDLoc dl(Node);
1571   EVT VT = Node->getValueType(0);
1572   SDValue Tmp1 = SDValue(Node, 0);
1573   SDValue Tmp2 = SDValue(Node, 1);
1574   SDValue Tmp3 = Node->getOperand(2);
1575   SDValue Chain = Tmp1.getOperand(0);
1576 
1577   // Chain the dynamic stack allocation so that it doesn't modify the stack
1578   // pointer when other instructions are using the stack.
1579   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1580 
1581   SDValue Size  = Tmp2.getOperand(1);
1582   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1583   Chain = SP.getValue(1);
1584   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
1585   unsigned StackAlign =
1586       DAG.getSubtarget().getFrameLowering()->getStackAlignment();
1587   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
1588   if (Align > StackAlign)
1589     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1590                        DAG.getConstant(-(uint64_t)Align, dl, VT));
1591   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1592 
1593   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1594                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1595 
1596   Results.push_back(Tmp1);
1597   Results.push_back(Tmp2);
1598 }
1599 
1600 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1601 /// target.
1602 ///
1603 /// If the SETCC has been legalized using AND / OR, then the legalized node
1604 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1605 /// will be set to false.
1606 ///
1607 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1608 /// then the values of LHS and RHS will be swapped, CC will be set to the
1609 /// new condition, and NeedInvert will be set to false.
1610 ///
1611 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1612 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1613 /// will be set to true. The caller must invert the result of the SETCC with
1614 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1615 /// of a true/false result.
1616 ///
1617 /// \returns true if the SetCC has been legalized, false if it hasn't.
LegalizeSetCCCondCode(EVT VT,SDValue & LHS,SDValue & RHS,SDValue & CC,bool & NeedInvert,const SDLoc & dl)1618 bool SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT, SDValue &LHS,
1619                                                  SDValue &RHS, SDValue &CC,
1620                                                  bool &NeedInvert,
1621                                                  const SDLoc &dl) {
1622   MVT OpVT = LHS.getSimpleValueType();
1623   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1624   NeedInvert = false;
1625   bool NeedSwap = false;
1626   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1627   default: llvm_unreachable("Unknown condition code action!");
1628   case TargetLowering::Legal:
1629     // Nothing to do.
1630     break;
1631   case TargetLowering::Expand: {
1632     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1633     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1634       std::swap(LHS, RHS);
1635       CC = DAG.getCondCode(InvCC);
1636       return true;
1637     }
1638     // Swapping operands didn't work. Try inverting the condition.
1639     InvCC = getSetCCInverse(CCCode, OpVT.isInteger());
1640     if (!TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1641       // If inverting the condition is not enough, try swapping operands
1642       // on top of it.
1643       InvCC = ISD::getSetCCSwappedOperands(InvCC);
1644       NeedSwap = true;
1645     }
1646     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1647       CC = DAG.getCondCode(InvCC);
1648       NeedInvert = true;
1649       if (NeedSwap)
1650         std::swap(LHS, RHS);
1651       return true;
1652     }
1653 
1654     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1655     unsigned Opc = 0;
1656     switch (CCCode) {
1657     default: llvm_unreachable("Don't know how to expand this condition!");
1658     case ISD::SETO:
1659         assert(TLI.isCondCodeLegal(ISD::SETOEQ, OpVT)
1660             && "If SETO is expanded, SETOEQ must be legal!");
1661         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1662     case ISD::SETUO:
1663         assert(TLI.isCondCodeLegal(ISD::SETUNE, OpVT)
1664             && "If SETUO is expanded, SETUNE must be legal!");
1665         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1666     case ISD::SETOEQ:
1667     case ISD::SETOGT:
1668     case ISD::SETOGE:
1669     case ISD::SETOLT:
1670     case ISD::SETOLE:
1671     case ISD::SETONE:
1672     case ISD::SETUEQ:
1673     case ISD::SETUNE:
1674     case ISD::SETUGT:
1675     case ISD::SETUGE:
1676     case ISD::SETULT:
1677     case ISD::SETULE:
1678         // If we are floating point, assign and break, otherwise fall through.
1679         if (!OpVT.isInteger()) {
1680           // We can use the 4th bit to tell if we are the unordered
1681           // or ordered version of the opcode.
1682           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1683           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1684           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1685           break;
1686         }
1687         // Fallthrough if we are unsigned integer.
1688         LLVM_FALLTHROUGH;
1689     case ISD::SETLE:
1690     case ISD::SETGT:
1691     case ISD::SETGE:
1692     case ISD::SETLT:
1693     case ISD::SETNE:
1694     case ISD::SETEQ:
1695       // If all combinations of inverting the condition and swapping operands
1696       // didn't work then we have no means to expand the condition.
1697       llvm_unreachable("Don't know how to expand this condition!");
1698     }
1699 
1700     SDValue SetCC1, SetCC2;
1701     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1702       // If we aren't the ordered or unorder operation,
1703       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1704       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
1705       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
1706     } else {
1707       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1708       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1);
1709       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2);
1710     }
1711     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1712     RHS = SDValue();
1713     CC  = SDValue();
1714     return true;
1715   }
1716   }
1717   return false;
1718 }
1719 
1720 /// Emit a store/load combination to the stack.  This stores
1721 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1722 /// a load from the stack slot to DestVT, extending it if needed.
1723 /// The resultant code need not be legal.
EmitStackConvert(SDValue SrcOp,EVT SlotVT,EVT DestVT,const SDLoc & dl)1724 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1725                                                EVT DestVT, const SDLoc &dl) {
1726   // Create the stack frame object.
1727   unsigned SrcAlign = DAG.getDataLayout().getPrefTypeAlignment(
1728       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1729   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
1730 
1731   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1732   int SPFI = StackPtrFI->getIndex();
1733   MachinePointerInfo PtrInfo =
1734       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1735 
1736   unsigned SrcSize = SrcOp.getValueSizeInBits();
1737   unsigned SlotSize = SlotVT.getSizeInBits();
1738   unsigned DestSize = DestVT.getSizeInBits();
1739   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1740   unsigned DestAlign = DAG.getDataLayout().getPrefTypeAlignment(DestType);
1741 
1742   // Emit a store to the stack slot.  Use a truncstore if the input value is
1743   // later than DestVT.
1744   SDValue Store;
1745 
1746   if (SrcSize > SlotSize)
1747     Store = DAG.getTruncStore(DAG.getEntryNode(), dl, SrcOp, FIPtr, PtrInfo,
1748                               SlotVT, SrcAlign);
1749   else {
1750     assert(SrcSize == SlotSize && "Invalid store");
1751     Store =
1752         DAG.getStore(DAG.getEntryNode(), dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1753   }
1754 
1755   // Result is a load from the stack slot.
1756   if (SlotSize == DestSize)
1757     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1758 
1759   assert(SlotSize < DestSize && "Unknown extension!");
1760   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1761                         DestAlign);
1762 }
1763 
ExpandSCALAR_TO_VECTOR(SDNode * Node)1764 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1765   SDLoc dl(Node);
1766   // Create a vector sized/aligned stack slot, store the value to element #0,
1767   // then load the whole vector back out.
1768   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1769 
1770   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1771   int SPFI = StackPtrFI->getIndex();
1772 
1773   SDValue Ch = DAG.getTruncStore(
1774       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1775       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1776       Node->getValueType(0).getVectorElementType());
1777   return DAG.getLoad(
1778       Node->getValueType(0), dl, Ch, StackPtr,
1779       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1780 }
1781 
1782 static bool
ExpandBVWithShuffles(SDNode * Node,SelectionDAG & DAG,const TargetLowering & TLI,SDValue & Res)1783 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1784                      const TargetLowering &TLI, SDValue &Res) {
1785   unsigned NumElems = Node->getNumOperands();
1786   SDLoc dl(Node);
1787   EVT VT = Node->getValueType(0);
1788 
1789   // Try to group the scalars into pairs, shuffle the pairs together, then
1790   // shuffle the pairs of pairs together, etc. until the vector has
1791   // been built. This will work only if all of the necessary shuffle masks
1792   // are legal.
1793 
1794   // We do this in two phases; first to check the legality of the shuffles,
1795   // and next, assuming that all shuffles are legal, to create the new nodes.
1796   for (int Phase = 0; Phase < 2; ++Phase) {
1797     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1798                                                               NewIntermedVals;
1799     for (unsigned i = 0; i < NumElems; ++i) {
1800       SDValue V = Node->getOperand(i);
1801       if (V.isUndef())
1802         continue;
1803 
1804       SDValue Vec;
1805       if (Phase)
1806         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1807       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1808     }
1809 
1810     while (IntermedVals.size() > 2) {
1811       NewIntermedVals.clear();
1812       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1813         // This vector and the next vector are shuffled together (simply to
1814         // append the one to the other).
1815         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1816 
1817         SmallVector<int, 16> FinalIndices;
1818         FinalIndices.reserve(IntermedVals[i].second.size() +
1819                              IntermedVals[i+1].second.size());
1820 
1821         int k = 0;
1822         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1823              ++j, ++k) {
1824           ShuffleVec[k] = j;
1825           FinalIndices.push_back(IntermedVals[i].second[j]);
1826         }
1827         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1828              ++j, ++k) {
1829           ShuffleVec[k] = NumElems + j;
1830           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1831         }
1832 
1833         SDValue Shuffle;
1834         if (Phase)
1835           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1836                                          IntermedVals[i+1].first,
1837                                          ShuffleVec);
1838         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1839           return false;
1840         NewIntermedVals.push_back(
1841             std::make_pair(Shuffle, std::move(FinalIndices)));
1842       }
1843 
1844       // If we had an odd number of defined values, then append the last
1845       // element to the array of new vectors.
1846       if ((IntermedVals.size() & 1) != 0)
1847         NewIntermedVals.push_back(IntermedVals.back());
1848 
1849       IntermedVals.swap(NewIntermedVals);
1850     }
1851 
1852     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1853            "Invalid number of intermediate vectors");
1854     SDValue Vec1 = IntermedVals[0].first;
1855     SDValue Vec2;
1856     if (IntermedVals.size() > 1)
1857       Vec2 = IntermedVals[1].first;
1858     else if (Phase)
1859       Vec2 = DAG.getUNDEF(VT);
1860 
1861     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1862     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1863       ShuffleVec[IntermedVals[0].second[i]] = i;
1864     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1865       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1866 
1867     if (Phase)
1868       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1869     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1870       return false;
1871   }
1872 
1873   return true;
1874 }
1875 
1876 /// Expand a BUILD_VECTOR node on targets that don't
1877 /// support the operation, but do support the resultant vector type.
ExpandBUILD_VECTOR(SDNode * Node)1878 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1879   unsigned NumElems = Node->getNumOperands();
1880   SDValue Value1, Value2;
1881   SDLoc dl(Node);
1882   EVT VT = Node->getValueType(0);
1883   EVT OpVT = Node->getOperand(0).getValueType();
1884   EVT EltVT = VT.getVectorElementType();
1885 
1886   // If the only non-undef value is the low element, turn this into a
1887   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1888   bool isOnlyLowElement = true;
1889   bool MoreThanTwoValues = false;
1890   bool isConstant = true;
1891   for (unsigned i = 0; i < NumElems; ++i) {
1892     SDValue V = Node->getOperand(i);
1893     if (V.isUndef())
1894       continue;
1895     if (i > 0)
1896       isOnlyLowElement = false;
1897     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1898       isConstant = false;
1899 
1900     if (!Value1.getNode()) {
1901       Value1 = V;
1902     } else if (!Value2.getNode()) {
1903       if (V != Value1)
1904         Value2 = V;
1905     } else if (V != Value1 && V != Value2) {
1906       MoreThanTwoValues = true;
1907     }
1908   }
1909 
1910   if (!Value1.getNode())
1911     return DAG.getUNDEF(VT);
1912 
1913   if (isOnlyLowElement)
1914     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1915 
1916   // If all elements are constants, create a load from the constant pool.
1917   if (isConstant) {
1918     SmallVector<Constant*, 16> CV;
1919     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1920       if (ConstantFPSDNode *V =
1921           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1922         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1923       } else if (ConstantSDNode *V =
1924                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1925         if (OpVT==EltVT)
1926           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1927         else {
1928           // If OpVT and EltVT don't match, EltVT is not legal and the
1929           // element values have been promoted/truncated earlier.  Undo this;
1930           // we don't want a v16i8 to become a v16i32 for example.
1931           const ConstantInt *CI = V->getConstantIntValue();
1932           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1933                                         CI->getZExtValue()));
1934         }
1935       } else {
1936         assert(Node->getOperand(i).isUndef());
1937         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1938         CV.push_back(UndefValue::get(OpNTy));
1939       }
1940     }
1941     Constant *CP = ConstantVector::get(CV);
1942     SDValue CPIdx =
1943         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1944     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
1945     return DAG.getLoad(
1946         VT, dl, DAG.getEntryNode(), CPIdx,
1947         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
1948         Alignment);
1949   }
1950 
1951   SmallSet<SDValue, 16> DefinedValues;
1952   for (unsigned i = 0; i < NumElems; ++i) {
1953     if (Node->getOperand(i).isUndef())
1954       continue;
1955     DefinedValues.insert(Node->getOperand(i));
1956   }
1957 
1958   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1959     if (!MoreThanTwoValues) {
1960       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1961       for (unsigned i = 0; i < NumElems; ++i) {
1962         SDValue V = Node->getOperand(i);
1963         if (V.isUndef())
1964           continue;
1965         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1966       }
1967       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1968         // Get the splatted value into the low element of a vector register.
1969         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1970         SDValue Vec2;
1971         if (Value2.getNode())
1972           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
1973         else
1974           Vec2 = DAG.getUNDEF(VT);
1975 
1976         // Return shuffle(LowValVec, undef, <0,0,0,0>)
1977         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1978       }
1979     } else {
1980       SDValue Res;
1981       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
1982         return Res;
1983     }
1984   }
1985 
1986   // Otherwise, we can't handle this case efficiently.
1987   return ExpandVectorBuildThroughStack(Node);
1988 }
1989 
1990 // Expand a node into a call to a libcall.  If the result value
1991 // does not fit into a register, return the lo part and set the hi part to the
1992 // by-reg argument.  If it does fit into a single register, return the result
1993 // and leave the Hi part unset.
ExpandLibCall(RTLIB::Libcall LC,SDNode * Node,bool isSigned)1994 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
1995                                             bool isSigned) {
1996   TargetLowering::ArgListTy Args;
1997   TargetLowering::ArgListEntry Entry;
1998   for (const SDValue &Op : Node->op_values()) {
1999     EVT ArgVT = Op.getValueType();
2000     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2001     Entry.Node = Op;
2002     Entry.Ty = ArgTy;
2003     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2004     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2005     Args.push_back(Entry);
2006   }
2007   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2008                                          TLI.getPointerTy(DAG.getDataLayout()));
2009 
2010   EVT RetVT = Node->getValueType(0);
2011   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2012 
2013   // By default, the input chain to this libcall is the entry node of the
2014   // function. If the libcall is going to be emitted as a tail call then
2015   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2016   // node which is being folded has a non-entry input chain.
2017   SDValue InChain = DAG.getEntryNode();
2018 
2019   // isTailCall may be true since the callee does not reference caller stack
2020   // frame. Check if it's in the right position and that the return types match.
2021   SDValue TCChain = InChain;
2022   const Function &F = DAG.getMachineFunction().getFunction();
2023   bool isTailCall =
2024       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2025       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2026   if (isTailCall)
2027     InChain = TCChain;
2028 
2029   TargetLowering::CallLoweringInfo CLI(DAG);
2030   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2031   CLI.setDebugLoc(SDLoc(Node))
2032       .setChain(InChain)
2033       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2034                     std::move(Args))
2035       .setTailCall(isTailCall)
2036       .setSExtResult(signExtend)
2037       .setZExtResult(!signExtend)
2038       .setIsPostTypeLegalization(true);
2039 
2040   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2041 
2042   if (!CallInfo.second.getNode()) {
2043     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump());
2044     // It's a tailcall, return the chain (which is the DAG root).
2045     return DAG.getRoot();
2046   }
2047 
2048   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump());
2049   return CallInfo.first;
2050 }
2051 
2052 /// Generate a libcall taking the given operands as arguments
2053 /// and returning a result of type RetVT.
ExpandLibCall(RTLIB::Libcall LC,EVT RetVT,const SDValue * Ops,unsigned NumOps,bool isSigned,const SDLoc & dl)2054 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, EVT RetVT,
2055                                             const SDValue *Ops, unsigned NumOps,
2056                                             bool isSigned, const SDLoc &dl) {
2057   TargetLowering::ArgListTy Args;
2058   Args.reserve(NumOps);
2059 
2060   TargetLowering::ArgListEntry Entry;
2061   for (unsigned i = 0; i != NumOps; ++i) {
2062     Entry.Node = Ops[i];
2063     Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
2064     Entry.IsSExt = isSigned;
2065     Entry.IsZExt = !isSigned;
2066     Args.push_back(Entry);
2067   }
2068   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2069                                          TLI.getPointerTy(DAG.getDataLayout()));
2070 
2071   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2072 
2073   TargetLowering::CallLoweringInfo CLI(DAG);
2074   CLI.setDebugLoc(dl)
2075       .setChain(DAG.getEntryNode())
2076       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2077                     std::move(Args))
2078       .setSExtResult(isSigned)
2079       .setZExtResult(!isSigned)
2080       .setIsPostTypeLegalization(true);
2081 
2082   std::pair<SDValue,SDValue> CallInfo = TLI.LowerCallTo(CLI);
2083 
2084   return CallInfo.first;
2085 }
2086 
2087 // Expand a node into a call to a libcall. Similar to
2088 // ExpandLibCall except that the first operand is the in-chain.
2089 std::pair<SDValue, SDValue>
ExpandChainLibCall(RTLIB::Libcall LC,SDNode * Node,bool isSigned)2090 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
2091                                          SDNode *Node,
2092                                          bool isSigned) {
2093   SDValue InChain = Node->getOperand(0);
2094 
2095   TargetLowering::ArgListTy Args;
2096   TargetLowering::ArgListEntry Entry;
2097   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
2098     EVT ArgVT = Node->getOperand(i).getValueType();
2099     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2100     Entry.Node = Node->getOperand(i);
2101     Entry.Ty = ArgTy;
2102     Entry.IsSExt = isSigned;
2103     Entry.IsZExt = !isSigned;
2104     Args.push_back(Entry);
2105   }
2106   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2107                                          TLI.getPointerTy(DAG.getDataLayout()));
2108 
2109   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
2110 
2111   TargetLowering::CallLoweringInfo CLI(DAG);
2112   CLI.setDebugLoc(SDLoc(Node))
2113       .setChain(InChain)
2114       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2115                     std::move(Args))
2116       .setSExtResult(isSigned)
2117       .setZExtResult(!isSigned);
2118 
2119   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2120 
2121   return CallInfo;
2122 }
2123 
ExpandFPLibCall(SDNode * Node,RTLIB::Libcall Call_F32,RTLIB::Libcall Call_F64,RTLIB::Libcall Call_F80,RTLIB::Libcall Call_F128,RTLIB::Libcall Call_PPCF128)2124 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2125                                               RTLIB::Libcall Call_F32,
2126                                               RTLIB::Libcall Call_F64,
2127                                               RTLIB::Libcall Call_F80,
2128                                               RTLIB::Libcall Call_F128,
2129                                               RTLIB::Libcall Call_PPCF128) {
2130   if (Node->isStrictFPOpcode())
2131     Node = DAG.mutateStrictFPToFP(Node);
2132 
2133   RTLIB::Libcall LC;
2134   switch (Node->getSimpleValueType(0).SimpleTy) {
2135   default: llvm_unreachable("Unexpected request for libcall!");
2136   case MVT::f32: LC = Call_F32; break;
2137   case MVT::f64: LC = Call_F64; break;
2138   case MVT::f80: LC = Call_F80; break;
2139   case MVT::f128: LC = Call_F128; break;
2140   case MVT::ppcf128: LC = Call_PPCF128; break;
2141   }
2142   return ExpandLibCall(LC, Node, false);
2143 }
2144 
ExpandIntLibCall(SDNode * Node,bool isSigned,RTLIB::Libcall Call_I8,RTLIB::Libcall Call_I16,RTLIB::Libcall Call_I32,RTLIB::Libcall Call_I64,RTLIB::Libcall Call_I128)2145 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2146                                                RTLIB::Libcall Call_I8,
2147                                                RTLIB::Libcall Call_I16,
2148                                                RTLIB::Libcall Call_I32,
2149                                                RTLIB::Libcall Call_I64,
2150                                                RTLIB::Libcall Call_I128) {
2151   RTLIB::Libcall LC;
2152   switch (Node->getSimpleValueType(0).SimpleTy) {
2153   default: llvm_unreachable("Unexpected request for libcall!");
2154   case MVT::i8:   LC = Call_I8; break;
2155   case MVT::i16:  LC = Call_I16; break;
2156   case MVT::i32:  LC = Call_I32; break;
2157   case MVT::i64:  LC = Call_I64; break;
2158   case MVT::i128: LC = Call_I128; break;
2159   }
2160   return ExpandLibCall(LC, Node, isSigned);
2161 }
2162 
2163 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2164 void
ExpandDivRemLibCall(SDNode * Node,SmallVectorImpl<SDValue> & Results)2165 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2166                                           SmallVectorImpl<SDValue> &Results) {
2167   unsigned Opcode = Node->getOpcode();
2168   bool isSigned = Opcode == ISD::SDIVREM;
2169 
2170   RTLIB::Libcall LC;
2171   switch (Node->getSimpleValueType(0).SimpleTy) {
2172   default: llvm_unreachable("Unexpected request for libcall!");
2173   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2174   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2175   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2176   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2177   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2178   }
2179 
2180   // The input chain to this libcall is the entry node of the function.
2181   // Legalizing the call will automatically add the previous call to the
2182   // dependence.
2183   SDValue InChain = DAG.getEntryNode();
2184 
2185   EVT RetVT = Node->getValueType(0);
2186   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2187 
2188   TargetLowering::ArgListTy Args;
2189   TargetLowering::ArgListEntry Entry;
2190   for (const SDValue &Op : Node->op_values()) {
2191     EVT ArgVT = Op.getValueType();
2192     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2193     Entry.Node = Op;
2194     Entry.Ty = ArgTy;
2195     Entry.IsSExt = isSigned;
2196     Entry.IsZExt = !isSigned;
2197     Args.push_back(Entry);
2198   }
2199 
2200   // Also pass the return address of the remainder.
2201   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2202   Entry.Node = FIPtr;
2203   Entry.Ty = RetTy->getPointerTo();
2204   Entry.IsSExt = isSigned;
2205   Entry.IsZExt = !isSigned;
2206   Args.push_back(Entry);
2207 
2208   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2209                                          TLI.getPointerTy(DAG.getDataLayout()));
2210 
2211   SDLoc dl(Node);
2212   TargetLowering::CallLoweringInfo CLI(DAG);
2213   CLI.setDebugLoc(dl)
2214       .setChain(InChain)
2215       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2216                     std::move(Args))
2217       .setSExtResult(isSigned)
2218       .setZExtResult(!isSigned);
2219 
2220   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2221 
2222   // Remainder is loaded back from the stack frame.
2223   SDValue Rem =
2224       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2225   Results.push_back(CallInfo.first);
2226   Results.push_back(Rem);
2227 }
2228 
2229 /// Return true if sincos libcall is available.
isSinCosLibcallAvailable(SDNode * Node,const TargetLowering & TLI)2230 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2231   RTLIB::Libcall LC;
2232   switch (Node->getSimpleValueType(0).SimpleTy) {
2233   default: llvm_unreachable("Unexpected request for libcall!");
2234   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2235   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2236   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2237   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2238   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2239   }
2240   return TLI.getLibcallName(LC) != nullptr;
2241 }
2242 
2243 /// Only issue sincos libcall if both sin and cos are needed.
useSinCos(SDNode * Node)2244 static bool useSinCos(SDNode *Node) {
2245   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2246     ? ISD::FCOS : ISD::FSIN;
2247 
2248   SDValue Op0 = Node->getOperand(0);
2249   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2250        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2251     SDNode *User = *UI;
2252     if (User == Node)
2253       continue;
2254     // The other user might have been turned into sincos already.
2255     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2256       return true;
2257   }
2258   return false;
2259 }
2260 
2261 /// Issue libcalls to sincos to compute sin / cos pairs.
2262 void
ExpandSinCosLibCall(SDNode * Node,SmallVectorImpl<SDValue> & Results)2263 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2264                                           SmallVectorImpl<SDValue> &Results) {
2265   RTLIB::Libcall LC;
2266   switch (Node->getSimpleValueType(0).SimpleTy) {
2267   default: llvm_unreachable("Unexpected request for libcall!");
2268   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2269   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2270   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2271   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2272   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2273   }
2274 
2275   // The input chain to this libcall is the entry node of the function.
2276   // Legalizing the call will automatically add the previous call to the
2277   // dependence.
2278   SDValue InChain = DAG.getEntryNode();
2279 
2280   EVT RetVT = Node->getValueType(0);
2281   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2282 
2283   TargetLowering::ArgListTy Args;
2284   TargetLowering::ArgListEntry Entry;
2285 
2286   // Pass the argument.
2287   Entry.Node = Node->getOperand(0);
2288   Entry.Ty = RetTy;
2289   Entry.IsSExt = false;
2290   Entry.IsZExt = false;
2291   Args.push_back(Entry);
2292 
2293   // Pass the return address of sin.
2294   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2295   Entry.Node = SinPtr;
2296   Entry.Ty = RetTy->getPointerTo();
2297   Entry.IsSExt = false;
2298   Entry.IsZExt = false;
2299   Args.push_back(Entry);
2300 
2301   // Also pass the return address of the cos.
2302   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2303   Entry.Node = CosPtr;
2304   Entry.Ty = RetTy->getPointerTo();
2305   Entry.IsSExt = false;
2306   Entry.IsZExt = false;
2307   Args.push_back(Entry);
2308 
2309   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2310                                          TLI.getPointerTy(DAG.getDataLayout()));
2311 
2312   SDLoc dl(Node);
2313   TargetLowering::CallLoweringInfo CLI(DAG);
2314   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2315       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2316       std::move(Args));
2317 
2318   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2319 
2320   Results.push_back(
2321       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2322   Results.push_back(
2323       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2324 }
2325 
2326 /// This function is responsible for legalizing a
2327 /// INT_TO_FP operation of the specified operand when the target requests that
2328 /// we expand it.  At this point, we know that the result and operand types are
2329 /// legal for the target.
ExpandLegalINT_TO_FP(bool isSigned,SDValue Op0,EVT DestVT,const SDLoc & dl)2330 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0,
2331                                                    EVT DestVT,
2332                                                    const SDLoc &dl) {
2333   EVT SrcVT = Op0.getValueType();
2334 
2335   // TODO: Should any fast-math-flags be set for the created nodes?
2336   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2337   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2338     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2339                          "expansion\n");
2340 
2341     // Get the stack frame index of a 8 byte buffer.
2342     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2343 
2344     // word offset constant for Hi/Lo address computation
2345     SDValue WordOff = DAG.getConstant(sizeof(int), dl,
2346                                       StackSlot.getValueType());
2347     // set up Hi and Lo (into buffer) address based on endian
2348     SDValue Hi = StackSlot;
2349     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
2350                              StackSlot, WordOff);
2351     if (DAG.getDataLayout().isLittleEndian())
2352       std::swap(Hi, Lo);
2353 
2354     // if signed map to unsigned space
2355     SDValue Op0Mapped;
2356     if (isSigned) {
2357       // constant used to invert sign bit (signed to unsigned mapping)
2358       SDValue SignBit = DAG.getConstant(0x80000000u, dl, MVT::i32);
2359       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
2360     } else {
2361       Op0Mapped = Op0;
2362     }
2363     // store the lo of the constructed double - based on integer input
2364     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl, Op0Mapped, Lo,
2365                                   MachinePointerInfo());
2366     // initial hi portion of constructed double
2367     SDValue InitialHi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2368     // store the hi of the constructed double - biased exponent
2369     SDValue Store2 =
2370         DAG.getStore(Store1, dl, InitialHi, Hi, MachinePointerInfo());
2371     // load the constructed double
2372     SDValue Load =
2373         DAG.getLoad(MVT::f64, dl, Store2, StackSlot, MachinePointerInfo());
2374     // FP constant to bias correct the final result
2375     SDValue Bias = DAG.getConstantFP(isSigned ?
2376                                      BitsToDouble(0x4330000080000000ULL) :
2377                                      BitsToDouble(0x4330000000000000ULL),
2378                                      dl, MVT::f64);
2379     // subtract the bias
2380     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2381     // final result
2382     SDValue Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2383     return Result;
2384   }
2385   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2386   // Code below here assumes !isSigned without checking again.
2387 
2388   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2389 
2390   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2391                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2392   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2393           Four = DAG.getIntPtrConstant(4, dl);
2394   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2395                                     SignSet, Four, Zero);
2396 
2397   // If the sign bit of the integer is set, the large number will be treated
2398   // as a negative number.  To counteract this, the dynamic code adds an
2399   // offset depending on the data type.
2400   uint64_t FF;
2401   switch (SrcVT.getSimpleVT().SimpleTy) {
2402   default: llvm_unreachable("Unsupported integer type!");
2403   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2404   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2405   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2406   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2407   }
2408   if (DAG.getDataLayout().isLittleEndian())
2409     FF <<= 32;
2410   Constant *FudgeFactor = ConstantInt::get(
2411                                        Type::getInt64Ty(*DAG.getContext()), FF);
2412 
2413   SDValue CPIdx =
2414       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2415   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
2416   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2417   Alignment = std::min(Alignment, 4u);
2418   SDValue FudgeInReg;
2419   if (DestVT == MVT::f32)
2420     FudgeInReg = DAG.getLoad(
2421         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2422         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2423         Alignment);
2424   else {
2425     SDValue Load = DAG.getExtLoad(
2426         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2427         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2428         Alignment);
2429     HandleSDNode Handle(Load);
2430     LegalizeOp(Load.getNode());
2431     FudgeInReg = Handle.getValue();
2432   }
2433 
2434   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2435 }
2436 
2437 /// This function is responsible for legalizing a
2438 /// *INT_TO_FP operation of the specified operand when the target requests that
2439 /// we promote it.  At this point, we know that the result and operand types are
2440 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2441 /// operation that takes a larger input.
PromoteLegalINT_TO_FP(SDValue LegalOp,EVT DestVT,bool isSigned,const SDLoc & dl)2442 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT,
2443                                                     bool isSigned,
2444                                                     const SDLoc &dl) {
2445   // First step, figure out the appropriate *INT_TO_FP operation to use.
2446   EVT NewInTy = LegalOp.getValueType();
2447 
2448   unsigned OpToUse = 0;
2449 
2450   // Scan for the appropriate larger type to use.
2451   while (true) {
2452     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2453     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2454 
2455     // If the target supports SINT_TO_FP of this type, use it.
2456     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
2457       OpToUse = ISD::SINT_TO_FP;
2458       break;
2459     }
2460     if (isSigned) continue;
2461 
2462     // If the target supports UINT_TO_FP of this type, use it.
2463     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
2464       OpToUse = ISD::UINT_TO_FP;
2465       break;
2466     }
2467 
2468     // Otherwise, try a larger type.
2469   }
2470 
2471   // Okay, we found the operation and type to use.  Zero extend our input to the
2472   // desired type then run the operation on it.
2473   return DAG.getNode(OpToUse, dl, DestVT,
2474                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2475                                  dl, NewInTy, LegalOp));
2476 }
2477 
2478 /// This function is responsible for legalizing a
2479 /// FP_TO_*INT operation of the specified operand when the target requests that
2480 /// we promote it.  At this point, we know that the result and operand types are
2481 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2482 /// operation that returns a larger result.
PromoteLegalFP_TO_INT(SDValue LegalOp,EVT DestVT,bool isSigned,const SDLoc & dl)2483 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT,
2484                                                     bool isSigned,
2485                                                     const SDLoc &dl) {
2486   // First step, figure out the appropriate FP_TO*INT operation to use.
2487   EVT NewOutTy = DestVT;
2488 
2489   unsigned OpToUse = 0;
2490 
2491   // Scan for the appropriate larger type to use.
2492   while (true) {
2493     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2494     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2495 
2496     // A larger signed type can hold all unsigned values of the requested type,
2497     // so using FP_TO_SINT is valid
2498     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
2499       OpToUse = ISD::FP_TO_SINT;
2500       break;
2501     }
2502 
2503     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2504     if (!isSigned && TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
2505       OpToUse = ISD::FP_TO_UINT;
2506       break;
2507     }
2508 
2509     // Otherwise, try a larger type.
2510   }
2511 
2512   // Okay, we found the operation and type to use.
2513   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2514 
2515   // Truncate the result of the extended FP_TO_*INT operation to the desired
2516   // size.
2517   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2518 }
2519 
2520 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
ExpandBITREVERSE(SDValue Op,const SDLoc & dl)2521 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2522   EVT VT = Op.getValueType();
2523   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2524   unsigned Sz = VT.getScalarSizeInBits();
2525 
2526   SDValue Tmp, Tmp2, Tmp3;
2527 
2528   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2529   // and finally the i1 pairs.
2530   // TODO: We can easily support i4/i2 legal types if any target ever does.
2531   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2532     // Create the masks - repeating the pattern every byte.
2533     APInt MaskHi4(Sz, 0), MaskHi2(Sz, 0), MaskHi1(Sz, 0);
2534     APInt MaskLo4(Sz, 0), MaskLo2(Sz, 0), MaskLo1(Sz, 0);
2535     for (unsigned J = 0; J != Sz; J += 8) {
2536       MaskHi4 = MaskHi4 | (0xF0ull << J);
2537       MaskLo4 = MaskLo4 | (0x0Full << J);
2538       MaskHi2 = MaskHi2 | (0xCCull << J);
2539       MaskLo2 = MaskLo2 | (0x33ull << J);
2540       MaskHi1 = MaskHi1 | (0xAAull << J);
2541       MaskLo1 = MaskLo1 | (0x55ull << J);
2542     }
2543 
2544     // BSWAP if the type is wider than a single byte.
2545     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2546 
2547     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2548     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2549     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2550     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, SHVT));
2551     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, SHVT));
2552     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2553 
2554     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2555     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2556     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2557     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, SHVT));
2558     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, SHVT));
2559     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2560 
2561     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2562     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2563     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2564     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, SHVT));
2565     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, SHVT));
2566     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2567     return Tmp;
2568   }
2569 
2570   Tmp = DAG.getConstant(0, dl, VT);
2571   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2572     if (I < J)
2573       Tmp2 =
2574           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2575     else
2576       Tmp2 =
2577           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2578 
2579     APInt Shift(Sz, 1);
2580     Shift <<= J;
2581     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2582     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2583   }
2584 
2585   return Tmp;
2586 }
2587 
2588 /// Open code the operations for BSWAP of the specified operation.
ExpandBSWAP(SDValue Op,const SDLoc & dl)2589 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2590   EVT VT = Op.getValueType();
2591   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2592   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2593   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2594   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2595   case MVT::i16:
2596     Tmp2 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2597     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2598     return DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2599   case MVT::i32:
2600     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2601     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2602     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2603     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2604     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2605                        DAG.getConstant(0xFF0000, dl, VT));
2606     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2607     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2608     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2609     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2610   case MVT::i64:
2611     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2612     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2613     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2614     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2615     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2616     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2617     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2618     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2619     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2620                        DAG.getConstant(255ULL<<48, dl, VT));
2621     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2622                        DAG.getConstant(255ULL<<40, dl, VT));
2623     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2624                        DAG.getConstant(255ULL<<32, dl, VT));
2625     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2626                        DAG.getConstant(255ULL<<24, dl, VT));
2627     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2628                        DAG.getConstant(255ULL<<16, dl, VT));
2629     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2630                        DAG.getConstant(255ULL<<8 , dl, VT));
2631     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2632     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2633     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2634     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2635     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2636     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2637     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2638   }
2639 }
2640 
ExpandNode(SDNode * Node)2641 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2642   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2643   SmallVector<SDValue, 8> Results;
2644   SDLoc dl(Node);
2645   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2646   bool NeedInvert;
2647   switch (Node->getOpcode()) {
2648   case ISD::ABS:
2649     if (TLI.expandABS(Node, Tmp1, DAG))
2650       Results.push_back(Tmp1);
2651     break;
2652   case ISD::CTPOP:
2653     if (TLI.expandCTPOP(Node, Tmp1, DAG))
2654       Results.push_back(Tmp1);
2655     break;
2656   case ISD::CTLZ:
2657   case ISD::CTLZ_ZERO_UNDEF:
2658     if (TLI.expandCTLZ(Node, Tmp1, DAG))
2659       Results.push_back(Tmp1);
2660     break;
2661   case ISD::CTTZ:
2662   case ISD::CTTZ_ZERO_UNDEF:
2663     if (TLI.expandCTTZ(Node, Tmp1, DAG))
2664       Results.push_back(Tmp1);
2665     break;
2666   case ISD::BITREVERSE:
2667     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2668     break;
2669   case ISD::BSWAP:
2670     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2671     break;
2672   case ISD::FRAMEADDR:
2673   case ISD::RETURNADDR:
2674   case ISD::FRAME_TO_ARGS_OFFSET:
2675     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2676     break;
2677   case ISD::EH_DWARF_CFA: {
2678     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2679                                         TLI.getPointerTy(DAG.getDataLayout()));
2680     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2681                                  CfaArg.getValueType(),
2682                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2683                                              CfaArg.getValueType()),
2684                                  CfaArg);
2685     SDValue FA = DAG.getNode(
2686         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2687         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2688     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2689                                   FA, Offset));
2690     break;
2691   }
2692   case ISD::FLT_ROUNDS_:
2693     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2694     break;
2695   case ISD::EH_RETURN:
2696   case ISD::EH_LABEL:
2697   case ISD::PREFETCH:
2698   case ISD::VAEND:
2699   case ISD::EH_SJLJ_LONGJMP:
2700     // If the target didn't expand these, there's nothing to do, so just
2701     // preserve the chain and be done.
2702     Results.push_back(Node->getOperand(0));
2703     break;
2704   case ISD::READCYCLECOUNTER:
2705     // If the target didn't expand this, just return 'zero' and preserve the
2706     // chain.
2707     Results.append(Node->getNumValues() - 1,
2708                    DAG.getConstant(0, dl, Node->getValueType(0)));
2709     Results.push_back(Node->getOperand(0));
2710     break;
2711   case ISD::EH_SJLJ_SETJMP:
2712     // If the target didn't expand this, just return 'zero' and preserve the
2713     // chain.
2714     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2715     Results.push_back(Node->getOperand(0));
2716     break;
2717   case ISD::ATOMIC_LOAD: {
2718     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2719     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2720     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2721     SDValue Swap = DAG.getAtomicCmpSwap(
2722         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2723         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2724         cast<AtomicSDNode>(Node)->getMemOperand());
2725     Results.push_back(Swap.getValue(0));
2726     Results.push_back(Swap.getValue(1));
2727     break;
2728   }
2729   case ISD::ATOMIC_STORE: {
2730     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2731     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2732                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2733                                  Node->getOperand(0),
2734                                  Node->getOperand(1), Node->getOperand(2),
2735                                  cast<AtomicSDNode>(Node)->getMemOperand());
2736     Results.push_back(Swap.getValue(1));
2737     break;
2738   }
2739   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2740     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2741     // splits out the success value as a comparison. Expanding the resulting
2742     // ATOMIC_CMP_SWAP will produce a libcall.
2743     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2744     SDValue Res = DAG.getAtomicCmpSwap(
2745         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2746         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2747         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2748 
2749     SDValue ExtRes = Res;
2750     SDValue LHS = Res;
2751     SDValue RHS = Node->getOperand(1);
2752 
2753     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2754     EVT OuterType = Node->getValueType(0);
2755     switch (TLI.getExtendForAtomicOps()) {
2756     case ISD::SIGN_EXTEND:
2757       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2758                         DAG.getValueType(AtomicType));
2759       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2760                         Node->getOperand(2), DAG.getValueType(AtomicType));
2761       ExtRes = LHS;
2762       break;
2763     case ISD::ZERO_EXTEND:
2764       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2765                         DAG.getValueType(AtomicType));
2766       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2767       ExtRes = LHS;
2768       break;
2769     case ISD::ANY_EXTEND:
2770       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2771       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2772       break;
2773     default:
2774       llvm_unreachable("Invalid atomic op extension");
2775     }
2776 
2777     SDValue Success =
2778         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2779 
2780     Results.push_back(ExtRes.getValue(0));
2781     Results.push_back(Success);
2782     Results.push_back(Res.getValue(1));
2783     break;
2784   }
2785   case ISD::DYNAMIC_STACKALLOC:
2786     ExpandDYNAMIC_STACKALLOC(Node, Results);
2787     break;
2788   case ISD::MERGE_VALUES:
2789     for (unsigned i = 0; i < Node->getNumValues(); i++)
2790       Results.push_back(Node->getOperand(i));
2791     break;
2792   case ISD::UNDEF: {
2793     EVT VT = Node->getValueType(0);
2794     if (VT.isInteger())
2795       Results.push_back(DAG.getConstant(0, dl, VT));
2796     else {
2797       assert(VT.isFloatingPoint() && "Unknown value type!");
2798       Results.push_back(DAG.getConstantFP(0, dl, VT));
2799     }
2800     break;
2801   }
2802   case ISD::FP_ROUND:
2803   case ISD::BITCAST:
2804     Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
2805                             Node->getValueType(0), dl);
2806     Results.push_back(Tmp1);
2807     break;
2808   case ISD::FP_EXTEND:
2809     Tmp1 = EmitStackConvert(Node->getOperand(0),
2810                             Node->getOperand(0).getValueType(),
2811                             Node->getValueType(0), dl);
2812     Results.push_back(Tmp1);
2813     break;
2814   case ISD::SIGN_EXTEND_INREG: {
2815     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2816     EVT VT = Node->getValueType(0);
2817 
2818     // An in-register sign-extend of a boolean is a negation:
2819     // 'true' (1) sign-extended is -1.
2820     // 'false' (0) sign-extended is 0.
2821     // However, we must mask the high bits of the source operand because the
2822     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
2823 
2824     // TODO: Do this for vectors too?
2825     if (ExtraVT.getSizeInBits() == 1) {
2826       SDValue One = DAG.getConstant(1, dl, VT);
2827       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
2828       SDValue Zero = DAG.getConstant(0, dl, VT);
2829       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
2830       Results.push_back(Neg);
2831       break;
2832     }
2833 
2834     // NOTE: we could fall back on load/store here too for targets without
2835     // SRA.  However, it is doubtful that any exist.
2836     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2837     unsigned BitsDiff = VT.getScalarSizeInBits() -
2838                         ExtraVT.getScalarSizeInBits();
2839     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
2840     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
2841                        Node->getOperand(0), ShiftCst);
2842     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
2843     Results.push_back(Tmp1);
2844     break;
2845   }
2846   case ISD::FP_ROUND_INREG: {
2847     // The only way we can lower this is to turn it into a TRUNCSTORE,
2848     // EXTLOAD pair, targeting a temporary location (a stack slot).
2849 
2850     // NOTE: there is a choice here between constantly creating new stack
2851     // slots and always reusing the same one.  We currently always create
2852     // new ones, as reuse may inhibit scheduling.
2853     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2854     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
2855                             Node->getValueType(0), dl);
2856     Results.push_back(Tmp1);
2857     break;
2858   }
2859   case ISD::UINT_TO_FP:
2860     if (TLI.expandUINT_TO_FP(Node, Tmp1, DAG)) {
2861       Results.push_back(Tmp1);
2862       break;
2863     }
2864     LLVM_FALLTHROUGH;
2865   case ISD::SINT_TO_FP:
2866     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
2867                                 Node->getOperand(0), Node->getValueType(0), dl);
2868     Results.push_back(Tmp1);
2869     break;
2870   case ISD::FP_TO_SINT:
2871     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
2872       Results.push_back(Tmp1);
2873     break;
2874   case ISD::FP_TO_UINT:
2875     if (TLI.expandFP_TO_UINT(Node, Tmp1, DAG))
2876       Results.push_back(Tmp1);
2877     break;
2878   case ISD::VAARG:
2879     Results.push_back(DAG.expandVAArg(Node));
2880     Results.push_back(Results[0].getValue(1));
2881     break;
2882   case ISD::VACOPY:
2883     Results.push_back(DAG.expandVACopy(Node));
2884     break;
2885   case ISD::EXTRACT_VECTOR_ELT:
2886     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
2887       // This must be an access of the only element.  Return it.
2888       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
2889                          Node->getOperand(0));
2890     else
2891       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
2892     Results.push_back(Tmp1);
2893     break;
2894   case ISD::EXTRACT_SUBVECTOR:
2895     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
2896     break;
2897   case ISD::INSERT_SUBVECTOR:
2898     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
2899     break;
2900   case ISD::CONCAT_VECTORS:
2901     Results.push_back(ExpandVectorBuildThroughStack(Node));
2902     break;
2903   case ISD::SCALAR_TO_VECTOR:
2904     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
2905     break;
2906   case ISD::INSERT_VECTOR_ELT:
2907     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
2908                                               Node->getOperand(1),
2909                                               Node->getOperand(2), dl));
2910     break;
2911   case ISD::VECTOR_SHUFFLE: {
2912     SmallVector<int, 32> NewMask;
2913     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
2914 
2915     EVT VT = Node->getValueType(0);
2916     EVT EltVT = VT.getVectorElementType();
2917     SDValue Op0 = Node->getOperand(0);
2918     SDValue Op1 = Node->getOperand(1);
2919     if (!TLI.isTypeLegal(EltVT)) {
2920       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
2921 
2922       // BUILD_VECTOR operands are allowed to be wider than the element type.
2923       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
2924       // it.
2925       if (NewEltVT.bitsLT(EltVT)) {
2926         // Convert shuffle node.
2927         // If original node was v4i64 and the new EltVT is i32,
2928         // cast operands to v8i32 and re-build the mask.
2929 
2930         // Calculate new VT, the size of the new VT should be equal to original.
2931         EVT NewVT =
2932             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
2933                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
2934         assert(NewVT.bitsEq(VT));
2935 
2936         // cast operands to new VT
2937         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
2938         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
2939 
2940         // Convert the shuffle mask
2941         unsigned int factor =
2942                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
2943 
2944         // EltVT gets smaller
2945         assert(factor > 0);
2946 
2947         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
2948           if (Mask[i] < 0) {
2949             for (unsigned fi = 0; fi < factor; ++fi)
2950               NewMask.push_back(Mask[i]);
2951           }
2952           else {
2953             for (unsigned fi = 0; fi < factor; ++fi)
2954               NewMask.push_back(Mask[i]*factor+fi);
2955           }
2956         }
2957         Mask = NewMask;
2958         VT = NewVT;
2959       }
2960       EltVT = NewEltVT;
2961     }
2962     unsigned NumElems = VT.getVectorNumElements();
2963     SmallVector<SDValue, 16> Ops;
2964     for (unsigned i = 0; i != NumElems; ++i) {
2965       if (Mask[i] < 0) {
2966         Ops.push_back(DAG.getUNDEF(EltVT));
2967         continue;
2968       }
2969       unsigned Idx = Mask[i];
2970       if (Idx < NumElems)
2971         Ops.push_back(DAG.getNode(
2972             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
2973             DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout()))));
2974       else
2975         Ops.push_back(DAG.getNode(
2976             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
2977             DAG.getConstant(Idx - NumElems, dl,
2978                             TLI.getVectorIdxTy(DAG.getDataLayout()))));
2979     }
2980 
2981     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
2982     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
2983     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
2984     Results.push_back(Tmp1);
2985     break;
2986   }
2987   case ISD::EXTRACT_ELEMENT: {
2988     EVT OpTy = Node->getOperand(0).getValueType();
2989     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
2990       // 1 -> Hi
2991       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
2992                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
2993                                          TLI.getShiftAmountTy(
2994                                              Node->getOperand(0).getValueType(),
2995                                              DAG.getDataLayout())));
2996       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
2997     } else {
2998       // 0 -> Lo
2999       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3000                          Node->getOperand(0));
3001     }
3002     Results.push_back(Tmp1);
3003     break;
3004   }
3005   case ISD::STACKSAVE:
3006     // Expand to CopyFromReg if the target set
3007     // StackPointerRegisterToSaveRestore.
3008     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3009       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3010                                            Node->getValueType(0)));
3011       Results.push_back(Results[0].getValue(1));
3012     } else {
3013       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3014       Results.push_back(Node->getOperand(0));
3015     }
3016     break;
3017   case ISD::STACKRESTORE:
3018     // Expand to CopyToReg if the target set
3019     // StackPointerRegisterToSaveRestore.
3020     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3021       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3022                                          Node->getOperand(1)));
3023     } else {
3024       Results.push_back(Node->getOperand(0));
3025     }
3026     break;
3027   case ISD::GET_DYNAMIC_AREA_OFFSET:
3028     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3029     Results.push_back(Results[0].getValue(0));
3030     break;
3031   case ISD::FCOPYSIGN:
3032     Results.push_back(ExpandFCOPYSIGN(Node));
3033     break;
3034   case ISD::FNEG:
3035     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3036     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3037     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3038     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3039                        Node->getOperand(0));
3040     Results.push_back(Tmp1);
3041     break;
3042   case ISD::FABS:
3043     Results.push_back(ExpandFABS(Node));
3044     break;
3045   case ISD::SMIN:
3046   case ISD::SMAX:
3047   case ISD::UMIN:
3048   case ISD::UMAX: {
3049     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3050     ISD::CondCode Pred;
3051     switch (Node->getOpcode()) {
3052     default: llvm_unreachable("How did we get here?");
3053     case ISD::SMAX: Pred = ISD::SETGT; break;
3054     case ISD::SMIN: Pred = ISD::SETLT; break;
3055     case ISD::UMAX: Pred = ISD::SETUGT; break;
3056     case ISD::UMIN: Pred = ISD::SETULT; break;
3057     }
3058     Tmp1 = Node->getOperand(0);
3059     Tmp2 = Node->getOperand(1);
3060     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3061     Results.push_back(Tmp1);
3062     break;
3063   }
3064   case ISD::FMINNUM:
3065   case ISD::FMAXNUM: {
3066     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3067       Results.push_back(Expanded);
3068     break;
3069   }
3070   case ISD::FSIN:
3071   case ISD::FCOS: {
3072     EVT VT = Node->getValueType(0);
3073     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3074     // fcos which share the same operand and both are used.
3075     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3076          isSinCosLibcallAvailable(Node, TLI))
3077         && useSinCos(Node)) {
3078       SDVTList VTs = DAG.getVTList(VT, VT);
3079       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3080       if (Node->getOpcode() == ISD::FCOS)
3081         Tmp1 = Tmp1.getValue(1);
3082       Results.push_back(Tmp1);
3083     }
3084     break;
3085   }
3086   case ISD::FMAD:
3087     llvm_unreachable("Illegal fmad should never be formed");
3088 
3089   case ISD::FP16_TO_FP:
3090     if (Node->getValueType(0) != MVT::f32) {
3091       // We can extend to types bigger than f32 in two steps without changing
3092       // the result. Since "f16 -> f32" is much more commonly available, give
3093       // CodeGen the option of emitting that before resorting to a libcall.
3094       SDValue Res =
3095           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3096       Results.push_back(
3097           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3098     }
3099     break;
3100   case ISD::FP_TO_FP16:
3101     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3102     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3103       SDValue Op = Node->getOperand(0);
3104       MVT SVT = Op.getSimpleValueType();
3105       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3106           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3107         // Under fastmath, we can expand this node into a fround followed by
3108         // a float-half conversion.
3109         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3110                                        DAG.getIntPtrConstant(0, dl));
3111         Results.push_back(
3112             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3113       }
3114     }
3115     break;
3116   case ISD::ConstantFP: {
3117     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3118     // Check to see if this FP immediate is already legal.
3119     // If this is a legal constant, turn it into a TargetConstantFP node.
3120     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0)))
3121       Results.push_back(ExpandConstantFP(CFP, true));
3122     break;
3123   }
3124   case ISD::Constant: {
3125     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3126     Results.push_back(ExpandConstant(CP));
3127     break;
3128   }
3129   case ISD::FSUB: {
3130     EVT VT = Node->getValueType(0);
3131     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3132         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3133       const SDNodeFlags Flags = Node->getFlags();
3134       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3135       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3136       Results.push_back(Tmp1);
3137     }
3138     break;
3139   }
3140   case ISD::SUB: {
3141     EVT VT = Node->getValueType(0);
3142     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3143            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3144            "Don't know how to expand this subtraction!");
3145     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3146                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3147                                VT));
3148     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3149     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3150     break;
3151   }
3152   case ISD::UREM:
3153   case ISD::SREM: {
3154     EVT VT = Node->getValueType(0);
3155     bool isSigned = Node->getOpcode() == ISD::SREM;
3156     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
3157     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3158     Tmp2 = Node->getOperand(0);
3159     Tmp3 = Node->getOperand(1);
3160     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3161       SDVTList VTs = DAG.getVTList(VT, VT);
3162       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
3163       Results.push_back(Tmp1);
3164     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
3165       // X % Y -> X-X/Y*Y
3166       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
3167       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
3168       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
3169       Results.push_back(Tmp1);
3170     }
3171     break;
3172   }
3173   case ISD::UDIV:
3174   case ISD::SDIV: {
3175     bool isSigned = Node->getOpcode() == ISD::SDIV;
3176     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3177     EVT VT = Node->getValueType(0);
3178     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3179       SDVTList VTs = DAG.getVTList(VT, VT);
3180       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3181                          Node->getOperand(1));
3182       Results.push_back(Tmp1);
3183     }
3184     break;
3185   }
3186   case ISD::MULHU:
3187   case ISD::MULHS: {
3188     unsigned ExpandOpcode =
3189         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3190     EVT VT = Node->getValueType(0);
3191     SDVTList VTs = DAG.getVTList(VT, VT);
3192 
3193     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3194                        Node->getOperand(1));
3195     Results.push_back(Tmp1.getValue(1));
3196     break;
3197   }
3198   case ISD::UMUL_LOHI:
3199   case ISD::SMUL_LOHI: {
3200     SDValue LHS = Node->getOperand(0);
3201     SDValue RHS = Node->getOperand(1);
3202     MVT VT = LHS.getSimpleValueType();
3203     unsigned MULHOpcode =
3204         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3205 
3206     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3207       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3208       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3209       break;
3210     }
3211 
3212     SmallVector<SDValue, 4> Halves;
3213     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3214     assert(TLI.isTypeLegal(HalfType));
3215     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, Node, LHS, RHS, Halves,
3216                            HalfType, DAG,
3217                            TargetLowering::MulExpansionKind::Always)) {
3218       for (unsigned i = 0; i < 2; ++i) {
3219         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3220         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3221         SDValue Shift = DAG.getConstant(
3222             HalfType.getScalarSizeInBits(), dl,
3223             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3224         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3225         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3226       }
3227       break;
3228     }
3229     break;
3230   }
3231   case ISD::MUL: {
3232     EVT VT = Node->getValueType(0);
3233     SDVTList VTs = DAG.getVTList(VT, VT);
3234     // See if multiply or divide can be lowered using two-result operations.
3235     // We just need the low half of the multiply; try both the signed
3236     // and unsigned forms. If the target supports both SMUL_LOHI and
3237     // UMUL_LOHI, form a preference by checking which forms of plain
3238     // MULH it supports.
3239     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3240     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3241     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3242     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3243     unsigned OpToUse = 0;
3244     if (HasSMUL_LOHI && !HasMULHS) {
3245       OpToUse = ISD::SMUL_LOHI;
3246     } else if (HasUMUL_LOHI && !HasMULHU) {
3247       OpToUse = ISD::UMUL_LOHI;
3248     } else if (HasSMUL_LOHI) {
3249       OpToUse = ISD::SMUL_LOHI;
3250     } else if (HasUMUL_LOHI) {
3251       OpToUse = ISD::UMUL_LOHI;
3252     }
3253     if (OpToUse) {
3254       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3255                                     Node->getOperand(1)));
3256       break;
3257     }
3258 
3259     SDValue Lo, Hi;
3260     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3261     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3262         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3263         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3264         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3265         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3266                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3267       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3268       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3269       SDValue Shift =
3270           DAG.getConstant(HalfType.getSizeInBits(), dl,
3271                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3272       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3273       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3274     }
3275     break;
3276   }
3277   case ISD::FSHL:
3278   case ISD::FSHR:
3279     if (TLI.expandFunnelShift(Node, Tmp1, DAG))
3280       Results.push_back(Tmp1);
3281     break;
3282   case ISD::ROTL:
3283   case ISD::ROTR:
3284     if (TLI.expandROT(Node, Tmp1, DAG))
3285       Results.push_back(Tmp1);
3286     break;
3287   case ISD::SADDSAT:
3288   case ISD::UADDSAT:
3289   case ISD::SSUBSAT:
3290   case ISD::USUBSAT:
3291     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3292     break;
3293   case ISD::SMULFIX:
3294     Results.push_back(TLI.getExpandedFixedPointMultiplication(Node, DAG));
3295     break;
3296   case ISD::SADDO:
3297   case ISD::SSUBO: {
3298     SDValue LHS = Node->getOperand(0);
3299     SDValue RHS = Node->getOperand(1);
3300     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::SADDO ?
3301                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
3302                               LHS, RHS);
3303     Results.push_back(Sum);
3304     EVT ResultType = Node->getValueType(1);
3305     EVT OType = getSetCCResultType(Node->getValueType(0));
3306 
3307     SDValue Zero = DAG.getConstant(0, dl, LHS.getValueType());
3308 
3309     //   LHSSign -> LHS >= 0
3310     //   RHSSign -> RHS >= 0
3311     //   SumSign -> Sum >= 0
3312     //
3313     //   Add:
3314     //   Overflow -> (LHSSign == RHSSign) && (LHSSign != SumSign)
3315     //   Sub:
3316     //   Overflow -> (LHSSign != RHSSign) && (LHSSign != SumSign)
3317     SDValue LHSSign = DAG.getSetCC(dl, OType, LHS, Zero, ISD::SETGE);
3318     SDValue RHSSign = DAG.getSetCC(dl, OType, RHS, Zero, ISD::SETGE);
3319     SDValue SignsMatch = DAG.getSetCC(dl, OType, LHSSign, RHSSign,
3320                                       Node->getOpcode() == ISD::SADDO ?
3321                                       ISD::SETEQ : ISD::SETNE);
3322 
3323     SDValue SumSign = DAG.getSetCC(dl, OType, Sum, Zero, ISD::SETGE);
3324     SDValue SumSignNE = DAG.getSetCC(dl, OType, LHSSign, SumSign, ISD::SETNE);
3325 
3326     SDValue Cmp = DAG.getNode(ISD::AND, dl, OType, SignsMatch, SumSignNE);
3327     Results.push_back(DAG.getBoolExtOrTrunc(Cmp, dl, ResultType, ResultType));
3328     break;
3329   }
3330   case ISD::UADDO:
3331   case ISD::USUBO: {
3332     SDValue LHS = Node->getOperand(0);
3333     SDValue RHS = Node->getOperand(1);
3334     bool IsAdd = Node->getOpcode() == ISD::UADDO;
3335     // If ADD/SUBCARRY is legal, use that instead.
3336     unsigned OpcCarry = IsAdd ? ISD::ADDCARRY : ISD::SUBCARRY;
3337     if (TLI.isOperationLegalOrCustom(OpcCarry, Node->getValueType(0))) {
3338       SDValue CarryIn = DAG.getConstant(0, dl, Node->getValueType(1));
3339       SDValue NodeCarry = DAG.getNode(OpcCarry, dl, Node->getVTList(),
3340                                       { LHS, RHS, CarryIn });
3341       Results.push_back(SDValue(NodeCarry.getNode(), 0));
3342       Results.push_back(SDValue(NodeCarry.getNode(), 1));
3343       break;
3344     }
3345 
3346     SDValue Sum = DAG.getNode(IsAdd ? ISD::ADD : ISD::SUB, dl,
3347                               LHS.getValueType(), LHS, RHS);
3348     Results.push_back(Sum);
3349 
3350     EVT ResultType = Node->getValueType(1);
3351     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3352     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3353     SDValue SetCC = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3354 
3355     Results.push_back(DAG.getBoolExtOrTrunc(SetCC, dl, ResultType, ResultType));
3356     break;
3357   }
3358   case ISD::UMULO:
3359   case ISD::SMULO: {
3360     EVT VT = Node->getValueType(0);
3361     EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
3362     SDValue LHS = Node->getOperand(0);
3363     SDValue RHS = Node->getOperand(1);
3364     SDValue BottomHalf;
3365     SDValue TopHalf;
3366     static const unsigned Ops[2][3] =
3367         { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
3368           { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
3369     bool isSigned = Node->getOpcode() == ISD::SMULO;
3370     if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
3371       BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
3372       TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
3373     } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
3374       BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
3375                                RHS);
3376       TopHalf = BottomHalf.getValue(1);
3377     } else if (TLI.isTypeLegal(WideVT)) {
3378       LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
3379       RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
3380       Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
3381       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3382                                DAG.getIntPtrConstant(0, dl));
3383       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3384                             DAG.getIntPtrConstant(1, dl));
3385     } else {
3386       // We can fall back to a libcall with an illegal type for the MUL if we
3387       // have a libcall big enough.
3388       // Also, we can fall back to a division in some cases, but that's a big
3389       // performance hit in the general case.
3390       RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
3391       if (WideVT == MVT::i16)
3392         LC = RTLIB::MUL_I16;
3393       else if (WideVT == MVT::i32)
3394         LC = RTLIB::MUL_I32;
3395       else if (WideVT == MVT::i64)
3396         LC = RTLIB::MUL_I64;
3397       else if (WideVT == MVT::i128)
3398         LC = RTLIB::MUL_I128;
3399       assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
3400 
3401       SDValue HiLHS;
3402       SDValue HiRHS;
3403       if (isSigned) {
3404         // The high part is obtained by SRA'ing all but one of the bits of low
3405         // part.
3406         unsigned LoSize = VT.getSizeInBits();
3407         HiLHS =
3408             DAG.getNode(ISD::SRA, dl, VT, LHS,
3409                         DAG.getConstant(LoSize - 1, dl,
3410                                         TLI.getPointerTy(DAG.getDataLayout())));
3411         HiRHS =
3412             DAG.getNode(ISD::SRA, dl, VT, RHS,
3413                         DAG.getConstant(LoSize - 1, dl,
3414                                         TLI.getPointerTy(DAG.getDataLayout())));
3415       } else {
3416           HiLHS = DAG.getConstant(0, dl, VT);
3417           HiRHS = DAG.getConstant(0, dl, VT);
3418       }
3419 
3420       // Here we're passing the 2 arguments explicitly as 4 arguments that are
3421       // pre-lowered to the correct types. This all depends upon WideVT not
3422       // being a legal type for the architecture and thus has to be split to
3423       // two arguments.
3424       SDValue Ret;
3425       if(DAG.getDataLayout().isLittleEndian()) {
3426         // Halves of WideVT are packed into registers in different order
3427         // depending on platform endianness. This is usually handled by
3428         // the C calling convention, but we can't defer to it in
3429         // the legalizer.
3430         SDValue Args[] = { LHS, HiLHS, RHS, HiRHS };
3431         Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3432       } else {
3433         SDValue Args[] = { HiLHS, LHS, HiRHS, RHS };
3434         Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3435       }
3436       assert(Ret.getOpcode() == ISD::MERGE_VALUES &&
3437              "Ret value is a collection of constituent nodes holding result.");
3438       BottomHalf = Ret.getOperand(0);
3439       TopHalf = Ret.getOperand(1);
3440     }
3441 
3442     if (isSigned) {
3443       Tmp1 = DAG.getConstant(
3444           VT.getSizeInBits() - 1, dl,
3445           TLI.getShiftAmountTy(BottomHalf.getValueType(), DAG.getDataLayout()));
3446       Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
3447       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf, Tmp1,
3448                              ISD::SETNE);
3449     } else {
3450       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf,
3451                              DAG.getConstant(0, dl, VT), ISD::SETNE);
3452     }
3453 
3454     // Truncate the result if SetCC returns a larger type than needed.
3455     EVT RType = Node->getValueType(1);
3456     if (RType.getSizeInBits() < TopHalf.getValueSizeInBits())
3457       TopHalf = DAG.getNode(ISD::TRUNCATE, dl, RType, TopHalf);
3458 
3459     assert(RType.getSizeInBits() == TopHalf.getValueSizeInBits() &&
3460            "Unexpected result type for S/UMULO legalization");
3461 
3462     Results.push_back(BottomHalf);
3463     Results.push_back(TopHalf);
3464     break;
3465   }
3466   case ISD::BUILD_PAIR: {
3467     EVT PairTy = Node->getValueType(0);
3468     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3469     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3470     Tmp2 = DAG.getNode(
3471         ISD::SHL, dl, PairTy, Tmp2,
3472         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3473                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3474     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3475     break;
3476   }
3477   case ISD::SELECT:
3478     Tmp1 = Node->getOperand(0);
3479     Tmp2 = Node->getOperand(1);
3480     Tmp3 = Node->getOperand(2);
3481     if (Tmp1.getOpcode() == ISD::SETCC) {
3482       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3483                              Tmp2, Tmp3,
3484                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3485     } else {
3486       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3487                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3488                              Tmp2, Tmp3, ISD::SETNE);
3489     }
3490     Results.push_back(Tmp1);
3491     break;
3492   case ISD::BR_JT: {
3493     SDValue Chain = Node->getOperand(0);
3494     SDValue Table = Node->getOperand(1);
3495     SDValue Index = Node->getOperand(2);
3496 
3497     const DataLayout &TD = DAG.getDataLayout();
3498     EVT PTy = TLI.getPointerTy(TD);
3499 
3500     unsigned EntrySize =
3501       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3502 
3503     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3504     // This transformation needs to be done here since otherwise the MIPS
3505     // backend will end up emitting a three instruction multiply sequence
3506     // instead of a single shift and MSP430 will call a runtime function.
3507     if (llvm::isPowerOf2_32(EntrySize))
3508       Index = DAG.getNode(
3509           ISD::SHL, dl, Index.getValueType(), Index,
3510           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3511     else
3512       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3513                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3514     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3515                                Index, Table);
3516 
3517     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3518     SDValue LD = DAG.getExtLoad(
3519         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3520         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3521     Addr = LD;
3522     if (TLI.isJumpTableRelative()) {
3523       // For PIC, the sequence is:
3524       // BRIND(load(Jumptable + index) + RelocBase)
3525       // RelocBase can be JumpTable, GOT or some sort of global base.
3526       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3527                           TLI.getPICJumpTableRelocBase(Table, DAG));
3528     }
3529 
3530     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3531     Results.push_back(Tmp1);
3532     break;
3533   }
3534   case ISD::BRCOND:
3535     // Expand brcond's setcc into its constituent parts and create a BR_CC
3536     // Node.
3537     Tmp1 = Node->getOperand(0);
3538     Tmp2 = Node->getOperand(1);
3539     if (Tmp2.getOpcode() == ISD::SETCC) {
3540       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3541                          Tmp1, Tmp2.getOperand(2),
3542                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3543                          Node->getOperand(2));
3544     } else {
3545       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3546       if (Tmp2.isUndef() ||
3547           (Tmp2.getOpcode() == ISD::AND &&
3548            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3549            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3550         Tmp3 = Tmp2;
3551       else
3552         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3553                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3554       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3555                          DAG.getCondCode(ISD::SETNE), Tmp3,
3556                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3557                          Node->getOperand(2));
3558     }
3559     Results.push_back(Tmp1);
3560     break;
3561   case ISD::SETCC: {
3562     Tmp1 = Node->getOperand(0);
3563     Tmp2 = Node->getOperand(1);
3564     Tmp3 = Node->getOperand(2);
3565     bool Legalized = LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2,
3566                                            Tmp3, NeedInvert, dl);
3567 
3568     if (Legalized) {
3569       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3570       // condition code, create a new SETCC node.
3571       if (Tmp3.getNode())
3572         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3573                            Tmp1, Tmp2, Tmp3);
3574 
3575       // If we expanded the SETCC by inverting the condition code, then wrap
3576       // the existing SETCC in a NOT to restore the intended condition.
3577       if (NeedInvert)
3578         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3579 
3580       Results.push_back(Tmp1);
3581       break;
3582     }
3583 
3584     // Otherwise, SETCC for the given comparison type must be completely
3585     // illegal; expand it into a SELECT_CC.
3586     EVT VT = Node->getValueType(0);
3587     int TrueValue;
3588     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3589     case TargetLowering::ZeroOrOneBooleanContent:
3590     case TargetLowering::UndefinedBooleanContent:
3591       TrueValue = 1;
3592       break;
3593     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3594       TrueValue = -1;
3595       break;
3596     }
3597     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3598                        DAG.getConstant(TrueValue, dl, VT),
3599                        DAG.getConstant(0, dl, VT),
3600                        Tmp3);
3601     Results.push_back(Tmp1);
3602     break;
3603   }
3604   case ISD::SELECT_CC: {
3605     Tmp1 = Node->getOperand(0);   // LHS
3606     Tmp2 = Node->getOperand(1);   // RHS
3607     Tmp3 = Node->getOperand(2);   // True
3608     Tmp4 = Node->getOperand(3);   // False
3609     EVT VT = Node->getValueType(0);
3610     SDValue CC = Node->getOperand(4);
3611     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3612 
3613     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3614       // If the condition code is legal, then we need to expand this
3615       // node using SETCC and SELECT.
3616       EVT CmpVT = Tmp1.getValueType();
3617       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3618              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3619              "expanded.");
3620       EVT CCVT =
3621           TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), CmpVT);
3622       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC);
3623       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3624       break;
3625     }
3626 
3627     // SELECT_CC is legal, so the condition code must not be.
3628     bool Legalized = false;
3629     // Try to legalize by inverting the condition.  This is for targets that
3630     // might support an ordered version of a condition, but not the unordered
3631     // version (or vice versa).
3632     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp,
3633                                                Tmp1.getValueType().isInteger());
3634     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3635       // Use the new condition code and swap true and false
3636       Legalized = true;
3637       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3638     } else {
3639       // If The inverse is not legal, then try to swap the arguments using
3640       // the inverse condition code.
3641       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3642       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3643         // The swapped inverse condition is legal, so swap true and false,
3644         // lhs and rhs.
3645         Legalized = true;
3646         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3647       }
3648     }
3649 
3650     if (!Legalized) {
3651       Legalized = LegalizeSetCCCondCode(
3652           getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC, NeedInvert,
3653           dl);
3654 
3655       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3656 
3657       // If we expanded the SETCC by inverting the condition code, then swap
3658       // the True/False operands to match.
3659       if (NeedInvert)
3660         std::swap(Tmp3, Tmp4);
3661 
3662       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3663       // condition code, create a new SELECT_CC node.
3664       if (CC.getNode()) {
3665         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3666                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3667       } else {
3668         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3669         CC = DAG.getCondCode(ISD::SETNE);
3670         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3671                            Tmp2, Tmp3, Tmp4, CC);
3672       }
3673     }
3674     Results.push_back(Tmp1);
3675     break;
3676   }
3677   case ISD::BR_CC: {
3678     Tmp1 = Node->getOperand(0);              // Chain
3679     Tmp2 = Node->getOperand(2);              // LHS
3680     Tmp3 = Node->getOperand(3);              // RHS
3681     Tmp4 = Node->getOperand(1);              // CC
3682 
3683     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
3684         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, NeedInvert, dl);
3685     (void)Legalized;
3686     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3687 
3688     assert(!NeedInvert && "Don't know how to invert BR_CC!");
3689 
3690     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3691     // node.
3692     if (Tmp4.getNode()) {
3693       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3694                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3695     } else {
3696       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3697       Tmp4 = DAG.getCondCode(ISD::SETNE);
3698       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3699                          Tmp2, Tmp3, Node->getOperand(4));
3700     }
3701     Results.push_back(Tmp1);
3702     break;
3703   }
3704   case ISD::BUILD_VECTOR:
3705     Results.push_back(ExpandBUILD_VECTOR(Node));
3706     break;
3707   case ISD::SRA:
3708   case ISD::SRL:
3709   case ISD::SHL: {
3710     // Scalarize vector SRA/SRL/SHL.
3711     EVT VT = Node->getValueType(0);
3712     assert(VT.isVector() && "Unable to legalize non-vector shift");
3713     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3714     unsigned NumElem = VT.getVectorNumElements();
3715 
3716     SmallVector<SDValue, 8> Scalars;
3717     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3718       SDValue Ex = DAG.getNode(
3719           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(0),
3720           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3721       SDValue Sh = DAG.getNode(
3722           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(1),
3723           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3724       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3725                                     VT.getScalarType(), Ex, Sh));
3726     }
3727 
3728     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3729     ReplaceNode(SDValue(Node, 0), Result);
3730     break;
3731   }
3732   case ISD::GLOBAL_OFFSET_TABLE:
3733   case ISD::GlobalAddress:
3734   case ISD::GlobalTLSAddress:
3735   case ISD::ExternalSymbol:
3736   case ISD::ConstantPool:
3737   case ISD::JumpTable:
3738   case ISD::INTRINSIC_W_CHAIN:
3739   case ISD::INTRINSIC_WO_CHAIN:
3740   case ISD::INTRINSIC_VOID:
3741     // FIXME: Custom lowering for these operations shouldn't return null!
3742     break;
3743   }
3744 
3745   // Replace the original node with the legalized result.
3746   if (Results.empty()) {
3747     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3748     return false;
3749   }
3750 
3751   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3752   ReplaceNode(Node, Results.data());
3753   return true;
3754 }
3755 
ConvertNodeToLibcall(SDNode * Node)3756 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3757   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
3758   SmallVector<SDValue, 8> Results;
3759   SDLoc dl(Node);
3760   // FIXME: Check flags on the node to see if we can use a finite call.
3761   bool CanUseFiniteLibCall = TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath;
3762   unsigned Opc = Node->getOpcode();
3763   switch (Opc) {
3764   case ISD::ATOMIC_FENCE: {
3765     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3766     // FIXME: handle "fence singlethread" more efficiently.
3767     TargetLowering::ArgListTy Args;
3768 
3769     TargetLowering::CallLoweringInfo CLI(DAG);
3770     CLI.setDebugLoc(dl)
3771         .setChain(Node->getOperand(0))
3772         .setLibCallee(
3773             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3774             DAG.getExternalSymbol("__sync_synchronize",
3775                                   TLI.getPointerTy(DAG.getDataLayout())),
3776             std::move(Args));
3777 
3778     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3779 
3780     Results.push_back(CallResult.second);
3781     break;
3782   }
3783   // By default, atomic intrinsics are marked Legal and lowered. Targets
3784   // which don't support them directly, however, may want libcalls, in which
3785   // case they mark them Expand, and we get here.
3786   case ISD::ATOMIC_SWAP:
3787   case ISD::ATOMIC_LOAD_ADD:
3788   case ISD::ATOMIC_LOAD_SUB:
3789   case ISD::ATOMIC_LOAD_AND:
3790   case ISD::ATOMIC_LOAD_CLR:
3791   case ISD::ATOMIC_LOAD_OR:
3792   case ISD::ATOMIC_LOAD_XOR:
3793   case ISD::ATOMIC_LOAD_NAND:
3794   case ISD::ATOMIC_LOAD_MIN:
3795   case ISD::ATOMIC_LOAD_MAX:
3796   case ISD::ATOMIC_LOAD_UMIN:
3797   case ISD::ATOMIC_LOAD_UMAX:
3798   case ISD::ATOMIC_CMP_SWAP: {
3799     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3800     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
3801     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
3802 
3803     std::pair<SDValue, SDValue> Tmp = ExpandChainLibCall(LC, Node, false);
3804     Results.push_back(Tmp.first);
3805     Results.push_back(Tmp.second);
3806     break;
3807   }
3808   case ISD::TRAP: {
3809     // If this operation is not supported, lower it to 'abort()' call
3810     TargetLowering::ArgListTy Args;
3811     TargetLowering::CallLoweringInfo CLI(DAG);
3812     CLI.setDebugLoc(dl)
3813         .setChain(Node->getOperand(0))
3814         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3815                       DAG.getExternalSymbol(
3816                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
3817                       std::move(Args));
3818     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3819 
3820     Results.push_back(CallResult.second);
3821     break;
3822   }
3823   case ISD::FMINNUM:
3824   case ISD::STRICT_FMINNUM:
3825     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
3826                                       RTLIB::FMIN_F80, RTLIB::FMIN_F128,
3827                                       RTLIB::FMIN_PPCF128));
3828     break;
3829   case ISD::FMAXNUM:
3830   case ISD::STRICT_FMAXNUM:
3831     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
3832                                       RTLIB::FMAX_F80, RTLIB::FMAX_F128,
3833                                       RTLIB::FMAX_PPCF128));
3834     break;
3835   case ISD::FSQRT:
3836   case ISD::STRICT_FSQRT:
3837     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
3838                                       RTLIB::SQRT_F80, RTLIB::SQRT_F128,
3839                                       RTLIB::SQRT_PPCF128));
3840     break;
3841   case ISD::FCBRT:
3842     Results.push_back(ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
3843                                       RTLIB::CBRT_F80, RTLIB::CBRT_F128,
3844                                       RTLIB::CBRT_PPCF128));
3845     break;
3846   case ISD::FSIN:
3847   case ISD::STRICT_FSIN:
3848     Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
3849                                       RTLIB::SIN_F80, RTLIB::SIN_F128,
3850                                       RTLIB::SIN_PPCF128));
3851     break;
3852   case ISD::FCOS:
3853   case ISD::STRICT_FCOS:
3854     Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
3855                                       RTLIB::COS_F80, RTLIB::COS_F128,
3856                                       RTLIB::COS_PPCF128));
3857     break;
3858   case ISD::FSINCOS:
3859     // Expand into sincos libcall.
3860     ExpandSinCosLibCall(Node, Results);
3861     break;
3862   case ISD::FLOG:
3863   case ISD::STRICT_FLOG:
3864     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log_finite))
3865       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_FINITE_F32,
3866                                         RTLIB::LOG_FINITE_F64,
3867                                         RTLIB::LOG_FINITE_F80,
3868                                         RTLIB::LOG_FINITE_F128,
3869                                         RTLIB::LOG_FINITE_PPCF128));
3870     else
3871       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
3872                                         RTLIB::LOG_F80, RTLIB::LOG_F128,
3873                                         RTLIB::LOG_PPCF128));
3874     break;
3875   case ISD::FLOG2:
3876   case ISD::STRICT_FLOG2:
3877     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log2_finite))
3878       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_FINITE_F32,
3879                                         RTLIB::LOG2_FINITE_F64,
3880                                         RTLIB::LOG2_FINITE_F80,
3881                                         RTLIB::LOG2_FINITE_F128,
3882                                         RTLIB::LOG2_FINITE_PPCF128));
3883     else
3884       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
3885                                         RTLIB::LOG2_F80, RTLIB::LOG2_F128,
3886                                         RTLIB::LOG2_PPCF128));
3887     break;
3888   case ISD::FLOG10:
3889   case ISD::STRICT_FLOG10:
3890     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log10_finite))
3891       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_FINITE_F32,
3892                                         RTLIB::LOG10_FINITE_F64,
3893                                         RTLIB::LOG10_FINITE_F80,
3894                                         RTLIB::LOG10_FINITE_F128,
3895                                         RTLIB::LOG10_FINITE_PPCF128));
3896     else
3897       Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
3898                                         RTLIB::LOG10_F80, RTLIB::LOG10_F128,
3899                                         RTLIB::LOG10_PPCF128));
3900     break;
3901   case ISD::FEXP:
3902   case ISD::STRICT_FEXP:
3903     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp_finite))
3904       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_FINITE_F32,
3905                                         RTLIB::EXP_FINITE_F64,
3906                                         RTLIB::EXP_FINITE_F80,
3907                                         RTLIB::EXP_FINITE_F128,
3908                                         RTLIB::EXP_FINITE_PPCF128));
3909     else
3910       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
3911                                         RTLIB::EXP_F80, RTLIB::EXP_F128,
3912                                         RTLIB::EXP_PPCF128));
3913     break;
3914   case ISD::FEXP2:
3915   case ISD::STRICT_FEXP2:
3916     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp2_finite))
3917       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_FINITE_F32,
3918                                         RTLIB::EXP2_FINITE_F64,
3919                                         RTLIB::EXP2_FINITE_F80,
3920                                         RTLIB::EXP2_FINITE_F128,
3921                                         RTLIB::EXP2_FINITE_PPCF128));
3922     else
3923       Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
3924                                         RTLIB::EXP2_F80, RTLIB::EXP2_F128,
3925                                         RTLIB::EXP2_PPCF128));
3926     break;
3927   case ISD::FTRUNC:
3928   case ISD::STRICT_FTRUNC:
3929     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
3930                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
3931                                       RTLIB::TRUNC_PPCF128));
3932     break;
3933   case ISD::FFLOOR:
3934   case ISD::STRICT_FFLOOR:
3935     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
3936                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
3937                                       RTLIB::FLOOR_PPCF128));
3938     break;
3939   case ISD::FCEIL:
3940   case ISD::STRICT_FCEIL:
3941     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
3942                                       RTLIB::CEIL_F80, RTLIB::CEIL_F128,
3943                                       RTLIB::CEIL_PPCF128));
3944     break;
3945   case ISD::FRINT:
3946   case ISD::STRICT_FRINT:
3947     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
3948                                       RTLIB::RINT_F80, RTLIB::RINT_F128,
3949                                       RTLIB::RINT_PPCF128));
3950     break;
3951   case ISD::FNEARBYINT:
3952   case ISD::STRICT_FNEARBYINT:
3953     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
3954                                       RTLIB::NEARBYINT_F64,
3955                                       RTLIB::NEARBYINT_F80,
3956                                       RTLIB::NEARBYINT_F128,
3957                                       RTLIB::NEARBYINT_PPCF128));
3958     break;
3959   case ISD::FROUND:
3960   case ISD::STRICT_FROUND:
3961     Results.push_back(ExpandFPLibCall(Node, RTLIB::ROUND_F32,
3962                                       RTLIB::ROUND_F64,
3963                                       RTLIB::ROUND_F80,
3964                                       RTLIB::ROUND_F128,
3965                                       RTLIB::ROUND_PPCF128));
3966     break;
3967   case ISD::FPOWI:
3968   case ISD::STRICT_FPOWI:
3969     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
3970                                       RTLIB::POWI_F80, RTLIB::POWI_F128,
3971                                       RTLIB::POWI_PPCF128));
3972     break;
3973   case ISD::FPOW:
3974   case ISD::STRICT_FPOW:
3975     if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_pow_finite))
3976       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_FINITE_F32,
3977                                         RTLIB::POW_FINITE_F64,
3978                                         RTLIB::POW_FINITE_F80,
3979                                         RTLIB::POW_FINITE_F128,
3980                                         RTLIB::POW_FINITE_PPCF128));
3981     else
3982       Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
3983                                         RTLIB::POW_F80, RTLIB::POW_F128,
3984                                         RTLIB::POW_PPCF128));
3985     break;
3986   case ISD::FDIV:
3987     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
3988                                       RTLIB::DIV_F80, RTLIB::DIV_F128,
3989                                       RTLIB::DIV_PPCF128));
3990     break;
3991   case ISD::FREM:
3992   case ISD::STRICT_FREM:
3993     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
3994                                       RTLIB::REM_F80, RTLIB::REM_F128,
3995                                       RTLIB::REM_PPCF128));
3996     break;
3997   case ISD::FMA:
3998   case ISD::STRICT_FMA:
3999     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4000                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
4001                                       RTLIB::FMA_PPCF128));
4002     break;
4003   case ISD::FADD:
4004     Results.push_back(ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4005                                       RTLIB::ADD_F80, RTLIB::ADD_F128,
4006                                       RTLIB::ADD_PPCF128));
4007     break;
4008   case ISD::FMUL:
4009     Results.push_back(ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4010                                       RTLIB::MUL_F80, RTLIB::MUL_F128,
4011                                       RTLIB::MUL_PPCF128));
4012     break;
4013   case ISD::FP16_TO_FP:
4014     if (Node->getValueType(0) == MVT::f32) {
4015       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4016     }
4017     break;
4018   case ISD::FP_TO_FP16: {
4019     RTLIB::Libcall LC =
4020         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4021     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4022     Results.push_back(ExpandLibCall(LC, Node, false));
4023     break;
4024   }
4025   case ISD::FSUB:
4026     Results.push_back(ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4027                                       RTLIB::SUB_F80, RTLIB::SUB_F128,
4028                                       RTLIB::SUB_PPCF128));
4029     break;
4030   case ISD::SREM:
4031     Results.push_back(ExpandIntLibCall(Node, true,
4032                                        RTLIB::SREM_I8,
4033                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4034                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4035     break;
4036   case ISD::UREM:
4037     Results.push_back(ExpandIntLibCall(Node, false,
4038                                        RTLIB::UREM_I8,
4039                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4040                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4041     break;
4042   case ISD::SDIV:
4043     Results.push_back(ExpandIntLibCall(Node, true,
4044                                        RTLIB::SDIV_I8,
4045                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4046                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4047     break;
4048   case ISD::UDIV:
4049     Results.push_back(ExpandIntLibCall(Node, false,
4050                                        RTLIB::UDIV_I8,
4051                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4052                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4053     break;
4054   case ISD::SDIVREM:
4055   case ISD::UDIVREM:
4056     // Expand into divrem libcall
4057     ExpandDivRemLibCall(Node, Results);
4058     break;
4059   case ISD::MUL:
4060     Results.push_back(ExpandIntLibCall(Node, false,
4061                                        RTLIB::MUL_I8,
4062                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4063                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4064     break;
4065   case ISD::CTLZ_ZERO_UNDEF:
4066     switch (Node->getSimpleValueType(0).SimpleTy) {
4067     default:
4068       llvm_unreachable("LibCall explicitly requested, but not available");
4069     case MVT::i32:
4070       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4071       break;
4072     case MVT::i64:
4073       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4074       break;
4075     case MVT::i128:
4076       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4077       break;
4078     }
4079     break;
4080   }
4081 
4082   // Replace the original node with the legalized result.
4083   if (!Results.empty()) {
4084     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4085     ReplaceNode(Node, Results.data());
4086   } else
4087     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4088 }
4089 
4090 // Determine the vector type to use in place of an original scalar element when
4091 // promoting equally sized vectors.
getPromotedVectorElementType(const TargetLowering & TLI,MVT EltVT,MVT NewEltVT)4092 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4093                                         MVT EltVT, MVT NewEltVT) {
4094   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4095   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4096   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4097   return MidVT;
4098 }
4099 
PromoteNode(SDNode * Node)4100 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4101   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4102   SmallVector<SDValue, 8> Results;
4103   MVT OVT = Node->getSimpleValueType(0);
4104   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4105       Node->getOpcode() == ISD::SINT_TO_FP ||
4106       Node->getOpcode() == ISD::SETCC ||
4107       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4108       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4109     OVT = Node->getOperand(0).getSimpleValueType();
4110   }
4111   if (Node->getOpcode() == ISD::BR_CC)
4112     OVT = Node->getOperand(2).getSimpleValueType();
4113   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4114   SDLoc dl(Node);
4115   SDValue Tmp1, Tmp2, Tmp3;
4116   switch (Node->getOpcode()) {
4117   case ISD::CTTZ:
4118   case ISD::CTTZ_ZERO_UNDEF:
4119   case ISD::CTLZ:
4120   case ISD::CTLZ_ZERO_UNDEF:
4121   case ISD::CTPOP:
4122     // Zero extend the argument.
4123     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4124     if (Node->getOpcode() == ISD::CTTZ) {
4125       // The count is the same in the promoted type except if the original
4126       // value was zero.  This can be handled by setting the bit just off
4127       // the top of the original type.
4128       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4129                                         OVT.getSizeInBits());
4130       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4131                          DAG.getConstant(TopBit, dl, NVT));
4132     }
4133     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4134     // already the correct result.
4135     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4136     if (Node->getOpcode() == ISD::CTLZ ||
4137         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4138       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4139       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4140                           DAG.getConstant(NVT.getSizeInBits() -
4141                                           OVT.getSizeInBits(), dl, NVT));
4142     }
4143     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4144     break;
4145   case ISD::BITREVERSE:
4146   case ISD::BSWAP: {
4147     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4148     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4149     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4150     Tmp1 = DAG.getNode(
4151         ISD::SRL, dl, NVT, Tmp1,
4152         DAG.getConstant(DiffBits, dl,
4153                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4154 
4155     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4156     break;
4157   }
4158   case ISD::FP_TO_UINT:
4159   case ISD::FP_TO_SINT:
4160     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
4161                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
4162     Results.push_back(Tmp1);
4163     break;
4164   case ISD::UINT_TO_FP:
4165   case ISD::SINT_TO_FP:
4166     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
4167                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
4168     Results.push_back(Tmp1);
4169     break;
4170   case ISD::VAARG: {
4171     SDValue Chain = Node->getOperand(0); // Get the chain.
4172     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4173 
4174     unsigned TruncOp;
4175     if (OVT.isVector()) {
4176       TruncOp = ISD::BITCAST;
4177     } else {
4178       assert(OVT.isInteger()
4179         && "VAARG promotion is supported only for vectors or integer types");
4180       TruncOp = ISD::TRUNCATE;
4181     }
4182 
4183     // Perform the larger operation, then convert back
4184     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4185              Node->getConstantOperandVal(3));
4186     Chain = Tmp1.getValue(1);
4187 
4188     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4189 
4190     // Modified the chain result - switch anything that used the old chain to
4191     // use the new one.
4192     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4193     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4194     if (UpdatedNodes) {
4195       UpdatedNodes->insert(Tmp2.getNode());
4196       UpdatedNodes->insert(Chain.getNode());
4197     }
4198     ReplacedNode(Node);
4199     break;
4200   }
4201   case ISD::MUL:
4202   case ISD::SDIV:
4203   case ISD::SREM:
4204   case ISD::UDIV:
4205   case ISD::UREM:
4206   case ISD::AND:
4207   case ISD::OR:
4208   case ISD::XOR: {
4209     unsigned ExtOp, TruncOp;
4210     if (OVT.isVector()) {
4211       ExtOp   = ISD::BITCAST;
4212       TruncOp = ISD::BITCAST;
4213     } else {
4214       assert(OVT.isInteger() && "Cannot promote logic operation");
4215 
4216       switch (Node->getOpcode()) {
4217       default:
4218         ExtOp = ISD::ANY_EXTEND;
4219         break;
4220       case ISD::SDIV:
4221       case ISD::SREM:
4222         ExtOp = ISD::SIGN_EXTEND;
4223         break;
4224       case ISD::UDIV:
4225       case ISD::UREM:
4226         ExtOp = ISD::ZERO_EXTEND;
4227         break;
4228       }
4229       TruncOp = ISD::TRUNCATE;
4230     }
4231     // Promote each of the values to the new type.
4232     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4233     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4234     // Perform the larger operation, then convert back
4235     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4236     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4237     break;
4238   }
4239   case ISD::UMUL_LOHI:
4240   case ISD::SMUL_LOHI: {
4241     // Promote to a multiply in a wider integer type.
4242     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4243                                                          : ISD::SIGN_EXTEND;
4244     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4245     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4246     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4247 
4248     auto &DL = DAG.getDataLayout();
4249     unsigned OriginalSize = OVT.getScalarSizeInBits();
4250     Tmp2 = DAG.getNode(
4251         ISD::SRL, dl, NVT, Tmp1,
4252         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4253     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4254     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4255     break;
4256   }
4257   case ISD::SELECT: {
4258     unsigned ExtOp, TruncOp;
4259     if (Node->getValueType(0).isVector() ||
4260         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4261       ExtOp   = ISD::BITCAST;
4262       TruncOp = ISD::BITCAST;
4263     } else if (Node->getValueType(0).isInteger()) {
4264       ExtOp   = ISD::ANY_EXTEND;
4265       TruncOp = ISD::TRUNCATE;
4266     } else {
4267       ExtOp   = ISD::FP_EXTEND;
4268       TruncOp = ISD::FP_ROUND;
4269     }
4270     Tmp1 = Node->getOperand(0);
4271     // Promote each of the values to the new type.
4272     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4273     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4274     // Perform the larger operation, then round down.
4275     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4276     if (TruncOp != ISD::FP_ROUND)
4277       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4278     else
4279       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4280                          DAG.getIntPtrConstant(0, dl));
4281     Results.push_back(Tmp1);
4282     break;
4283   }
4284   case ISD::VECTOR_SHUFFLE: {
4285     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4286 
4287     // Cast the two input vectors.
4288     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4289     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4290 
4291     // Convert the shuffle mask to the right # elements.
4292     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4293     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4294     Results.push_back(Tmp1);
4295     break;
4296   }
4297   case ISD::SETCC: {
4298     unsigned ExtOp = ISD::FP_EXTEND;
4299     if (NVT.isInteger()) {
4300       ISD::CondCode CCCode =
4301         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4302       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4303     }
4304     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4305     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4306     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
4307                                   Tmp1, Tmp2, Node->getOperand(2)));
4308     break;
4309   }
4310   case ISD::BR_CC: {
4311     unsigned ExtOp = ISD::FP_EXTEND;
4312     if (NVT.isInteger()) {
4313       ISD::CondCode CCCode =
4314         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4315       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4316     }
4317     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4318     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4319     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4320                                   Node->getOperand(0), Node->getOperand(1),
4321                                   Tmp1, Tmp2, Node->getOperand(4)));
4322     break;
4323   }
4324   case ISD::FADD:
4325   case ISD::FSUB:
4326   case ISD::FMUL:
4327   case ISD::FDIV:
4328   case ISD::FREM:
4329   case ISD::FMINNUM:
4330   case ISD::FMAXNUM:
4331   case ISD::FPOW:
4332     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4333     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4334     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4335                        Node->getFlags());
4336     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4337                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4338     break;
4339   case ISD::FMA:
4340     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4341     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4342     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4343     Results.push_back(
4344         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4345                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4346                     DAG.getIntPtrConstant(0, dl)));
4347     break;
4348   case ISD::FCOPYSIGN:
4349   case ISD::FPOWI: {
4350     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4351     Tmp2 = Node->getOperand(1);
4352     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4353 
4354     // fcopysign doesn't change anything but the sign bit, so
4355     //   (fp_round (fcopysign (fpext a), b))
4356     // is as precise as
4357     //   (fp_round (fpext a))
4358     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4359     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4360     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4361                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4362     break;
4363   }
4364   case ISD::FFLOOR:
4365   case ISD::FCEIL:
4366   case ISD::FRINT:
4367   case ISD::FNEARBYINT:
4368   case ISD::FROUND:
4369   case ISD::FTRUNC:
4370   case ISD::FNEG:
4371   case ISD::FSQRT:
4372   case ISD::FSIN:
4373   case ISD::FCOS:
4374   case ISD::FLOG:
4375   case ISD::FLOG2:
4376   case ISD::FLOG10:
4377   case ISD::FABS:
4378   case ISD::FEXP:
4379   case ISD::FEXP2:
4380     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4381     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4382     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4383                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4384     break;
4385   case ISD::BUILD_VECTOR: {
4386     MVT EltVT = OVT.getVectorElementType();
4387     MVT NewEltVT = NVT.getVectorElementType();
4388 
4389     // Handle bitcasts to a different vector type with the same total bit size
4390     //
4391     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4392     //  =>
4393     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4394 
4395     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4396            "Invalid promote type for build_vector");
4397     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4398 
4399     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4400 
4401     SmallVector<SDValue, 8> NewOps;
4402     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4403       SDValue Op = Node->getOperand(I);
4404       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4405     }
4406 
4407     SDLoc SL(Node);
4408     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4409     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4410     Results.push_back(CvtVec);
4411     break;
4412   }
4413   case ISD::EXTRACT_VECTOR_ELT: {
4414     MVT EltVT = OVT.getVectorElementType();
4415     MVT NewEltVT = NVT.getVectorElementType();
4416 
4417     // Handle bitcasts to a different vector type with the same total bit size.
4418     //
4419     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4420     //  =>
4421     //  v4i32:castx = bitcast x:v2i64
4422     //
4423     // i64 = bitcast
4424     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4425     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4426     //
4427 
4428     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4429            "Invalid promote type for extract_vector_elt");
4430     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4431 
4432     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4433     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4434 
4435     SDValue Idx = Node->getOperand(1);
4436     EVT IdxVT = Idx.getValueType();
4437     SDLoc SL(Node);
4438     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4439     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4440 
4441     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4442 
4443     SmallVector<SDValue, 8> NewOps;
4444     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4445       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4446       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4447 
4448       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4449                                 CastVec, TmpIdx);
4450       NewOps.push_back(Elt);
4451     }
4452 
4453     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4454     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4455     break;
4456   }
4457   case ISD::INSERT_VECTOR_ELT: {
4458     MVT EltVT = OVT.getVectorElementType();
4459     MVT NewEltVT = NVT.getVectorElementType();
4460 
4461     // Handle bitcasts to a different vector type with the same total bit size
4462     //
4463     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4464     //  =>
4465     //  v4i32:castx = bitcast x:v2i64
4466     //  v2i32:casty = bitcast y:i64
4467     //
4468     // v2i64 = bitcast
4469     //   (v4i32 insert_vector_elt
4470     //       (v4i32 insert_vector_elt v4i32:castx,
4471     //                                (extract_vector_elt casty, 0), 2 * z),
4472     //        (extract_vector_elt casty, 1), (2 * z + 1))
4473 
4474     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4475            "Invalid promote type for insert_vector_elt");
4476     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4477 
4478     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4479     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4480 
4481     SDValue Val = Node->getOperand(1);
4482     SDValue Idx = Node->getOperand(2);
4483     EVT IdxVT = Idx.getValueType();
4484     SDLoc SL(Node);
4485 
4486     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4487     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4488 
4489     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4490     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4491 
4492     SDValue NewVec = CastVec;
4493     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4494       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4495       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4496 
4497       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4498                                 CastVal, IdxOffset);
4499 
4500       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4501                            NewVec, Elt, InEltIdx);
4502     }
4503 
4504     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4505     break;
4506   }
4507   case ISD::SCALAR_TO_VECTOR: {
4508     MVT EltVT = OVT.getVectorElementType();
4509     MVT NewEltVT = NVT.getVectorElementType();
4510 
4511     // Handle bitcasts to different vector type with the same total bit size.
4512     //
4513     // e.g. v2i64 = scalar_to_vector x:i64
4514     //   =>
4515     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4516     //
4517 
4518     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4519     SDValue Val = Node->getOperand(0);
4520     SDLoc SL(Node);
4521 
4522     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4523     SDValue Undef = DAG.getUNDEF(MidVT);
4524 
4525     SmallVector<SDValue, 8> NewElts;
4526     NewElts.push_back(CastVal);
4527     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4528       NewElts.push_back(Undef);
4529 
4530     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4531     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4532     Results.push_back(CvtVec);
4533     break;
4534   }
4535   }
4536 
4537   // Replace the original node with the legalized result.
4538   if (!Results.empty()) {
4539     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4540     ReplaceNode(Node, Results.data());
4541   } else
4542     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4543 }
4544 
4545 /// This is the entry point for the file.
Legalize()4546 void SelectionDAG::Legalize() {
4547   AssignTopologicalOrder();
4548 
4549   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4550   // Use a delete listener to remove nodes which were deleted during
4551   // legalization from LegalizeNodes. This is needed to handle the situation
4552   // where a new node is allocated by the object pool to the same address of a
4553   // previously deleted node.
4554   DAGNodeDeletedListener DeleteListener(
4555       *this,
4556       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4557 
4558   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4559 
4560   // Visit all the nodes. We start in topological order, so that we see
4561   // nodes with their original operands intact. Legalization can produce
4562   // new nodes which may themselves need to be legalized. Iterate until all
4563   // nodes have been legalized.
4564   while (true) {
4565     bool AnyLegalized = false;
4566     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4567       --NI;
4568 
4569       SDNode *N = &*NI;
4570       if (N->use_empty() && N != getRoot().getNode()) {
4571         ++NI;
4572         DeleteNode(N);
4573         continue;
4574       }
4575 
4576       if (LegalizedNodes.insert(N).second) {
4577         AnyLegalized = true;
4578         Legalizer.LegalizeOp(N);
4579 
4580         if (N->use_empty() && N != getRoot().getNode()) {
4581           ++NI;
4582           DeleteNode(N);
4583         }
4584       }
4585     }
4586     if (!AnyLegalized)
4587       break;
4588 
4589   }
4590 
4591   // Remove dead nodes now.
4592   RemoveDeadNodes();
4593 }
4594 
LegalizeOp(SDNode * N,SmallSetVector<SDNode *,16> & UpdatedNodes)4595 bool SelectionDAG::LegalizeOp(SDNode *N,
4596                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4597   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4598   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4599 
4600   // Directly insert the node in question, and legalize it. This will recurse
4601   // as needed through operands.
4602   LegalizedNodes.insert(N);
4603   Legalizer.LegalizeOp(N);
4604 
4605   return LegalizedNodes.count(N);
4606 }
4607