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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/SetVector.h"
15 #include "llvm/ADT/SmallPtrSet.h"
16 #include "llvm/ADT/SmallSet.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/MachineJumpTableInfo.h"
21 #include "llvm/CodeGen/SelectionDAG.h"
22 #include "llvm/CodeGen/SelectionDAGNodes.h"
23 #include "llvm/IR/CallingConv.h"
24 #include "llvm/IR/Constants.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/DebugInfo.h"
27 #include "llvm/IR/DerivedTypes.h"
28 #include "llvm/IR/Function.h"
29 #include "llvm/IR/LLVMContext.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Target/TargetFrameLowering.h"
35 #include "llvm/Target/TargetLowering.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetSubtargetInfo.h"
38 using namespace llvm;
39 
40 #define DEBUG_TYPE "legalizedag"
41 
42 namespace {
43 
44 struct FloatSignAsInt;
45 
46 //===----------------------------------------------------------------------===//
47 /// This takes an arbitrary SelectionDAG as input and
48 /// hacks on it until the target machine can handle it.  This involves
49 /// eliminating value sizes the machine cannot handle (promoting small sizes to
50 /// large sizes or splitting up large values into small values) as well as
51 /// eliminating operations the machine cannot handle.
52 ///
53 /// This code also does a small amount of optimization and recognition of idioms
54 /// as part of its processing.  For example, if a target does not support a
55 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
56 /// will attempt merge setcc and brc instructions into brcc's.
57 ///
58 class SelectionDAGLegalize {
59   const TargetMachine &TM;
60   const TargetLowering &TLI;
61   SelectionDAG &DAG;
62 
63   /// \brief The set of nodes which have already been legalized. We hold a
64   /// reference to it in order to update as necessary on node deletion.
65   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
66 
67   /// \brief A set of all the nodes updated during legalization.
68   SmallSetVector<SDNode *, 16> *UpdatedNodes;
69 
getSetCCResultType(EVT VT) const70   EVT getSetCCResultType(EVT VT) const {
71     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
72   }
73 
74   // Libcall insertion helpers.
75 
76 public:
SelectionDAGLegalize(SelectionDAG & DAG,SmallPtrSetImpl<SDNode * > & LegalizedNodes,SmallSetVector<SDNode *,16> * UpdatedNodes=nullptr)77   SelectionDAGLegalize(SelectionDAG &DAG,
78                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
79                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
80       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
81         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
82 
83   /// \brief Legalizes the given operation.
84   void LegalizeOp(SDNode *Node);
85 
86 private:
87   SDValue OptimizeFloatStore(StoreSDNode *ST);
88 
89   void LegalizeLoadOps(SDNode *Node);
90   void LegalizeStoreOps(SDNode *Node);
91 
92   /// Some targets cannot handle a variable
93   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
94   /// is necessary to spill the vector being inserted into to memory, perform
95   /// the insert there, and then read the result back.
96   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
97                                          const SDLoc &dl);
98   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
99                                   const SDLoc &dl);
100 
101   /// Return a vector shuffle operation which
102   /// performs the same shuffe in terms of order or result bytes, but on a type
103   /// whose vector element type is narrower than the original shuffle type.
104   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
105   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
106                                      SDValue N1, SDValue N2,
107                                      ArrayRef<int> Mask) const;
108 
109   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
110                              bool &NeedInvert, const SDLoc &dl);
111 
112   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
113   SDValue ExpandLibCall(RTLIB::Libcall LC, EVT RetVT, const SDValue *Ops,
114                         unsigned NumOps, bool isSigned, const SDLoc &dl);
115 
116   std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
117                                                  SDNode *Node, bool isSigned);
118   SDValue ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
119                           RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
120                           RTLIB::Libcall Call_F128,
121                           RTLIB::Libcall Call_PPCF128);
122   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
123                            RTLIB::Libcall Call_I8,
124                            RTLIB::Libcall Call_I16,
125                            RTLIB::Libcall Call_I32,
126                            RTLIB::Libcall Call_I64,
127                            RTLIB::Libcall Call_I128);
128   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
129   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
130 
131   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
132                            const SDLoc &dl);
133   SDValue ExpandBUILD_VECTOR(SDNode *Node);
134   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
135   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
136                                 SmallVectorImpl<SDValue> &Results);
137   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
138                          SDValue Value) const;
139   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
140                           SDValue NewIntValue) const;
141   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
142   SDValue ExpandFABS(SDNode *Node) const;
143   SDValue ExpandLegalINT_TO_FP(bool isSigned, SDValue LegalOp, EVT DestVT,
144                                const SDLoc &dl);
145   SDValue PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT, bool isSigned,
146                                 const SDLoc &dl);
147   SDValue PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT, bool isSigned,
148                                 const SDLoc &dl);
149 
150   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
151   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
152   SDValue ExpandBitCount(unsigned Opc, SDValue Op, const SDLoc &dl);
153 
154   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
155   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
156   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
157 
158   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
159   SDValue ExpandConstant(ConstantSDNode *CP);
160 
161   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
162   bool ExpandNode(SDNode *Node);
163   void ConvertNodeToLibcall(SDNode *Node);
164   void PromoteNode(SDNode *Node);
165 
166 public:
167   // Node replacement helpers
ReplacedNode(SDNode * N)168   void ReplacedNode(SDNode *N) {
169     LegalizedNodes.erase(N);
170     if (UpdatedNodes)
171       UpdatedNodes->insert(N);
172   }
ReplaceNode(SDNode * Old,SDNode * New)173   void ReplaceNode(SDNode *Old, SDNode *New) {
174     DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
175           dbgs() << "     with:      "; New->dump(&DAG));
176 
177     assert(Old->getNumValues() == New->getNumValues() &&
178            "Replacing one node with another that produces a different number "
179            "of values!");
180     DAG.ReplaceAllUsesWith(Old, New);
181     if (UpdatedNodes)
182       UpdatedNodes->insert(New);
183     ReplacedNode(Old);
184   }
ReplaceNode(SDValue Old,SDValue New)185   void ReplaceNode(SDValue Old, SDValue New) {
186     DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
187           dbgs() << "     with:      "; New->dump(&DAG));
188 
189     DAG.ReplaceAllUsesWith(Old, New);
190     if (UpdatedNodes)
191       UpdatedNodes->insert(New.getNode());
192     ReplacedNode(Old.getNode());
193   }
ReplaceNode(SDNode * Old,const SDValue * New)194   void ReplaceNode(SDNode *Old, const SDValue *New) {
195     DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
196 
197     DAG.ReplaceAllUsesWith(Old, New);
198     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
199       DEBUG(dbgs() << (i == 0 ? "     with:      "
200                               : "      and:      ");
201             New[i]->dump(&DAG));
202       if (UpdatedNodes)
203         UpdatedNodes->insert(New[i].getNode());
204     }
205     ReplacedNode(Old);
206   }
207 };
208 }
209 
210 /// Return a vector shuffle operation which
211 /// performs the same shuffe in terms of order or result bytes, but on a type
212 /// whose vector element type is narrower than the original shuffle type.
213 /// 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) const214 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
215     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
216     ArrayRef<int> Mask) const {
217   unsigned NumMaskElts = VT.getVectorNumElements();
218   unsigned NumDestElts = NVT.getVectorNumElements();
219   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
220 
221   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
222 
223   if (NumEltsGrowth == 1)
224     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
225 
226   SmallVector<int, 8> NewMask;
227   for (unsigned i = 0; i != NumMaskElts; ++i) {
228     int Idx = Mask[i];
229     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
230       if (Idx < 0)
231         NewMask.push_back(-1);
232       else
233         NewMask.push_back(Idx * NumEltsGrowth + j);
234     }
235   }
236   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
237   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
238   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
239 }
240 
241 /// Expands the ConstantFP node to an integer constant or
242 /// a load from the constant pool.
243 SDValue
ExpandConstantFP(ConstantFPSDNode * CFP,bool UseCP)244 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
245   bool Extend = false;
246   SDLoc dl(CFP);
247 
248   // If a FP immediate is precise when represented as a float and if the
249   // target can do an extending load from float to double, we put it into
250   // the constant pool as a float, even if it's is statically typed as a
251   // double.  This shrinks FP constants and canonicalizes them for targets where
252   // an FP extending load is the same cost as a normal load (such as on the x87
253   // fp stack or PPC FP unit).
254   EVT VT = CFP->getValueType(0);
255   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
256   if (!UseCP) {
257     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
258     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
259                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
260   }
261 
262   EVT OrigVT = VT;
263   EVT SVT = VT;
264   while (SVT != MVT::f32 && SVT != MVT::f16) {
265     SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
266     if (ConstantFPSDNode::isValueValidForType(SVT, CFP->getValueAPF()) &&
267         // Only do this if the target has a native EXTLOAD instruction from
268         // smaller type.
269         TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
270         TLI.ShouldShrinkFPConstant(OrigVT)) {
271       Type *SType = SVT.getTypeForEVT(*DAG.getContext());
272       LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
273       VT = SVT;
274       Extend = true;
275     }
276   }
277 
278   SDValue CPIdx =
279       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
280   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
281   if (Extend) {
282     SDValue Result = DAG.getExtLoad(
283         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
284         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
285         false, false, false, Alignment);
286     return Result;
287   }
288   SDValue Result =
289       DAG.getLoad(OrigVT, dl, DAG.getEntryNode(), CPIdx,
290                   MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
291                   false, false, false, Alignment);
292   return Result;
293 }
294 
295 /// Expands the Constant node to a load from the constant pool.
ExpandConstant(ConstantSDNode * CP)296 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
297   SDLoc dl(CP);
298   EVT VT = CP->getValueType(0);
299   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
300                                       TLI.getPointerTy(DAG.getDataLayout()));
301   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
302   SDValue Result =
303     DAG.getLoad(VT, dl, DAG.getEntryNode(), CPIdx,
304                 MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
305                 false, false, false, Alignment);
306   return Result;
307 }
308 
309 /// Some target cannot handle a variable insertion index for the
310 /// INSERT_VECTOR_ELT instruction.  In this case, it
311 /// is necessary to spill the vector being inserted into to memory, perform
312 /// the insert there, and then read the result back.
PerformInsertVectorEltInMemory(SDValue Vec,SDValue Val,SDValue Idx,const SDLoc & dl)313 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
314                                                              SDValue Val,
315                                                              SDValue Idx,
316                                                              const SDLoc &dl) {
317   SDValue Tmp1 = Vec;
318   SDValue Tmp2 = Val;
319   SDValue Tmp3 = Idx;
320 
321   // If the target doesn't support this, we have to spill the input vector
322   // to a temporary stack slot, update the element, then reload it.  This is
323   // badness.  We could also load the value into a vector register (either
324   // with a "move to register" or "extload into register" instruction, then
325   // permute it into place, if the idx is a constant and if the idx is
326   // supported by the target.
327   EVT VT    = Tmp1.getValueType();
328   EVT EltVT = VT.getVectorElementType();
329   EVT IdxVT = Tmp3.getValueType();
330   EVT PtrVT = TLI.getPointerTy(DAG.getDataLayout());
331   SDValue StackPtr = DAG.CreateStackTemporary(VT);
332 
333   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
334 
335   // Store the vector.
336   SDValue Ch = DAG.getStore(
337       DAG.getEntryNode(), dl, Tmp1, StackPtr,
338       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI), false,
339       false, 0);
340 
341   // Truncate or zero extend offset to target pointer type.
342   Tmp3 = DAG.getZExtOrTrunc(Tmp3, dl, PtrVT);
343   // Add the offset to the index.
344   unsigned EltSize = EltVT.getSizeInBits()/8;
345   Tmp3 = DAG.getNode(ISD::MUL, dl, IdxVT, Tmp3,
346                      DAG.getConstant(EltSize, dl, IdxVT));
347   SDValue StackPtr2 = DAG.getNode(ISD::ADD, dl, IdxVT, Tmp3, StackPtr);
348   // Store the scalar value.
349   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT,
350                          false, false, 0);
351   // Load the updated vector.
352   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
353                                                DAG.getMachineFunction(), SPFI),
354                      false, false, false, 0);
355 }
356 
ExpandINSERT_VECTOR_ELT(SDValue Vec,SDValue Val,SDValue Idx,const SDLoc & dl)357 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
358                                                       SDValue Idx,
359                                                       const SDLoc &dl) {
360   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
361     // SCALAR_TO_VECTOR requires that the type of the value being inserted
362     // match the element type of the vector being created, except for
363     // integers in which case the inserted value can be over width.
364     EVT EltVT = Vec.getValueType().getVectorElementType();
365     if (Val.getValueType() == EltVT ||
366         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
367       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
368                                   Vec.getValueType(), Val);
369 
370       unsigned NumElts = Vec.getValueType().getVectorNumElements();
371       // We generate a shuffle of InVec and ScVec, so the shuffle mask
372       // should be 0,1,2,3,4,5... with the appropriate element replaced with
373       // elt 0 of the RHS.
374       SmallVector<int, 8> ShufOps;
375       for (unsigned i = 0; i != NumElts; ++i)
376         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
377 
378       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
379     }
380   }
381   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
382 }
383 
OptimizeFloatStore(StoreSDNode * ST)384 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
385   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
386   // FIXME: We shouldn't do this for TargetConstantFP's.
387   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
388   // to phase ordering between legalized code and the dag combiner.  This
389   // probably means that we need to integrate dag combiner and legalizer
390   // together.
391   // We generally can't do this one for long doubles.
392   SDValue Chain = ST->getChain();
393   SDValue Ptr = ST->getBasePtr();
394   unsigned Alignment = ST->getAlignment();
395   bool isVolatile = ST->isVolatile();
396   bool isNonTemporal = ST->isNonTemporal();
397   AAMDNodes AAInfo = ST->getAAInfo();
398   SDLoc dl(ST);
399   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
400     if (CFP->getValueType(0) == MVT::f32 &&
401         TLI.isTypeLegal(MVT::i32)) {
402       SDValue Con = DAG.getConstant(CFP->getValueAPF().
403                                       bitcastToAPInt().zextOrTrunc(32),
404                                     SDLoc(CFP), MVT::i32);
405       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
406                           isVolatile, isNonTemporal, Alignment, AAInfo);
407     }
408 
409     if (CFP->getValueType(0) == MVT::f64) {
410       // If this target supports 64-bit registers, do a single 64-bit store.
411       if (TLI.isTypeLegal(MVT::i64)) {
412         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
413                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
414         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
415                             isVolatile, isNonTemporal, Alignment, AAInfo);
416       }
417 
418       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
419         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
420         // stores.  If the target supports neither 32- nor 64-bits, this
421         // xform is certainly not worth it.
422         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
423         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
424         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
425         if (DAG.getDataLayout().isBigEndian())
426           std::swap(Lo, Hi);
427 
428         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), isVolatile,
429                           isNonTemporal, Alignment, AAInfo);
430         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
431                           DAG.getConstant(4, dl, Ptr.getValueType()));
432         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
433                           ST->getPointerInfo().getWithOffset(4),
434                           isVolatile, isNonTemporal, MinAlign(Alignment, 4U),
435                           AAInfo);
436 
437         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
438       }
439     }
440   }
441   return SDValue(nullptr, 0);
442 }
443 
LegalizeStoreOps(SDNode * Node)444 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
445     StoreSDNode *ST = cast<StoreSDNode>(Node);
446     SDValue Chain = ST->getChain();
447     SDValue Ptr = ST->getBasePtr();
448     SDLoc dl(Node);
449 
450     unsigned Alignment = ST->getAlignment();
451     bool isVolatile = ST->isVolatile();
452     bool isNonTemporal = ST->isNonTemporal();
453     AAMDNodes AAInfo = ST->getAAInfo();
454 
455     if (!ST->isTruncatingStore()) {
456       if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
457         ReplaceNode(ST, OptStore);
458         return;
459       }
460 
461       {
462         SDValue Value = ST->getValue();
463         MVT VT = Value.getSimpleValueType();
464         switch (TLI.getOperationAction(ISD::STORE, VT)) {
465         default: llvm_unreachable("This action is not supported yet!");
466         case TargetLowering::Legal: {
467           // If this is an unaligned store and the target doesn't support it,
468           // expand it.
469           EVT MemVT = ST->getMemoryVT();
470           unsigned AS = ST->getAddressSpace();
471           unsigned Align = ST->getAlignment();
472           const DataLayout &DL = DAG.getDataLayout();
473           if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
474             SDValue Result = TLI.expandUnalignedStore(ST, DAG);
475             ReplaceNode(SDValue(ST, 0), Result);
476           }
477           break;
478         }
479         case TargetLowering::Custom: {
480           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
481           if (Res && Res != SDValue(Node, 0))
482             ReplaceNode(SDValue(Node, 0), Res);
483           return;
484         }
485         case TargetLowering::Promote: {
486           MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
487           assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
488                  "Can only promote stores to same size type");
489           Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
490           SDValue Result =
491             DAG.getStore(Chain, dl, Value, Ptr,
492                          ST->getPointerInfo(), isVolatile,
493                          isNonTemporal, Alignment, AAInfo);
494           ReplaceNode(SDValue(Node, 0), Result);
495           break;
496         }
497         }
498         return;
499       }
500     } else {
501       SDValue Value = ST->getValue();
502 
503       EVT StVT = ST->getMemoryVT();
504       unsigned StWidth = StVT.getSizeInBits();
505       auto &DL = DAG.getDataLayout();
506 
507       if (StWidth != StVT.getStoreSizeInBits()) {
508         // Promote to a byte-sized store with upper bits zero if not
509         // storing an integral number of bytes.  For example, promote
510         // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
511         EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
512                                     StVT.getStoreSizeInBits());
513         Value = DAG.getZeroExtendInReg(Value, dl, StVT);
514         SDValue Result =
515           DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
516                             NVT, isVolatile, isNonTemporal, Alignment, AAInfo);
517         ReplaceNode(SDValue(Node, 0), Result);
518       } else if (StWidth & (StWidth - 1)) {
519         // If not storing a power-of-2 number of bits, expand as two stores.
520         assert(!StVT.isVector() && "Unsupported truncstore!");
521         unsigned RoundWidth = 1 << Log2_32(StWidth);
522         assert(RoundWidth < StWidth);
523         unsigned ExtraWidth = StWidth - RoundWidth;
524         assert(ExtraWidth < RoundWidth);
525         assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
526                "Store size not an integral number of bytes!");
527         EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
528         EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
529         SDValue Lo, Hi;
530         unsigned IncrementSize;
531 
532         if (DL.isLittleEndian()) {
533           // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
534           // Store the bottom RoundWidth bits.
535           Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
536                                  RoundVT,
537                                  isVolatile, isNonTemporal, Alignment,
538                                  AAInfo);
539 
540           // Store the remaining ExtraWidth bits.
541           IncrementSize = RoundWidth / 8;
542           Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
543                             DAG.getConstant(IncrementSize, dl,
544                                             Ptr.getValueType()));
545           Hi = DAG.getNode(
546               ISD::SRL, dl, Value.getValueType(), Value,
547               DAG.getConstant(RoundWidth, dl,
548                               TLI.getShiftAmountTy(Value.getValueType(), DL)));
549           Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
550                              ST->getPointerInfo().getWithOffset(IncrementSize),
551                                  ExtraVT, isVolatile, isNonTemporal,
552                                  MinAlign(Alignment, IncrementSize), AAInfo);
553         } else {
554           // Big endian - avoid unaligned stores.
555           // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
556           // Store the top RoundWidth bits.
557           Hi = DAG.getNode(
558               ISD::SRL, dl, Value.getValueType(), Value,
559               DAG.getConstant(ExtraWidth, dl,
560                               TLI.getShiftAmountTy(Value.getValueType(), DL)));
561           Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
562                                  RoundVT, isVolatile, isNonTemporal, Alignment,
563                                  AAInfo);
564 
565           // Store the remaining ExtraWidth bits.
566           IncrementSize = RoundWidth / 8;
567           Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
568                             DAG.getConstant(IncrementSize, dl,
569                                             Ptr.getValueType()));
570           Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
571                               ST->getPointerInfo().getWithOffset(IncrementSize),
572                                  ExtraVT, isVolatile, isNonTemporal,
573                                  MinAlign(Alignment, IncrementSize), AAInfo);
574         }
575 
576         // The order of the stores doesn't matter.
577         SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
578         ReplaceNode(SDValue(Node, 0), Result);
579       } else {
580         switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
581         default: llvm_unreachable("This action is not supported yet!");
582         case TargetLowering::Legal: {
583           EVT MemVT = ST->getMemoryVT();
584           unsigned AS = ST->getAddressSpace();
585           unsigned Align = ST->getAlignment();
586           // If this is an unaligned store and the target doesn't support it,
587           // expand it.
588           if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
589             SDValue Result = TLI.expandUnalignedStore(ST, DAG);
590             ReplaceNode(SDValue(ST, 0), Result);
591           }
592           break;
593         }
594         case TargetLowering::Custom: {
595           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
596           if (Res && Res != SDValue(Node, 0))
597             ReplaceNode(SDValue(Node, 0), Res);
598           return;
599         }
600         case TargetLowering::Expand:
601           assert(!StVT.isVector() &&
602                  "Vector Stores are handled in LegalizeVectorOps");
603 
604           // TRUNCSTORE:i16 i32 -> STORE i16
605           assert(TLI.isTypeLegal(StVT) &&
606                  "Do not know how to expand this store!");
607           Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
608           SDValue Result =
609             DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
610                          isVolatile, isNonTemporal, Alignment, AAInfo);
611           ReplaceNode(SDValue(Node, 0), Result);
612           break;
613         }
614       }
615     }
616 }
617 
LegalizeLoadOps(SDNode * Node)618 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
619   LoadSDNode *LD = cast<LoadSDNode>(Node);
620   SDValue Chain = LD->getChain();  // The chain.
621   SDValue Ptr = LD->getBasePtr();  // The base pointer.
622   SDValue Value;                   // The value returned by the load op.
623   SDLoc dl(Node);
624 
625   ISD::LoadExtType ExtType = LD->getExtensionType();
626   if (ExtType == ISD::NON_EXTLOAD) {
627     MVT VT = Node->getSimpleValueType(0);
628     SDValue RVal = SDValue(Node, 0);
629     SDValue RChain = SDValue(Node, 1);
630 
631     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
632     default: llvm_unreachable("This action is not supported yet!");
633     case TargetLowering::Legal: {
634       EVT MemVT = LD->getMemoryVT();
635       unsigned AS = LD->getAddressSpace();
636       unsigned Align = LD->getAlignment();
637       const DataLayout &DL = DAG.getDataLayout();
638       // If this is an unaligned load and the target doesn't support it,
639       // expand it.
640       if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
641         std::tie(RVal, RChain) =  TLI.expandUnalignedLoad(LD, DAG);
642       }
643       break;
644     }
645     case TargetLowering::Custom: {
646       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
647         RVal = Res;
648         RChain = Res.getValue(1);
649       }
650       break;
651     }
652     case TargetLowering::Promote: {
653       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
654       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
655              "Can only promote loads to same size type");
656 
657       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
658       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
659       RChain = Res.getValue(1);
660       break;
661     }
662     }
663     if (RChain.getNode() != Node) {
664       assert(RVal.getNode() != Node && "Load must be completely replaced");
665       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
666       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
667       if (UpdatedNodes) {
668         UpdatedNodes->insert(RVal.getNode());
669         UpdatedNodes->insert(RChain.getNode());
670       }
671       ReplacedNode(Node);
672     }
673     return;
674   }
675 
676   EVT SrcVT = LD->getMemoryVT();
677   unsigned SrcWidth = SrcVT.getSizeInBits();
678   unsigned Alignment = LD->getAlignment();
679   bool isVolatile = LD->isVolatile();
680   bool isNonTemporal = LD->isNonTemporal();
681   bool isInvariant = LD->isInvariant();
682   AAMDNodes AAInfo = LD->getAAInfo();
683 
684   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
685       // Some targets pretend to have an i1 loading operation, and actually
686       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
687       // bits are guaranteed to be zero; it helps the optimizers understand
688       // that these bits are zero.  It is also useful for EXTLOAD, since it
689       // tells the optimizers that those bits are undefined.  It would be
690       // nice to have an effective generic way of getting these benefits...
691       // Until such a way is found, don't insist on promoting i1 here.
692       (SrcVT != MVT::i1 ||
693        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
694          TargetLowering::Promote)) {
695     // Promote to a byte-sized load if not loading an integral number of
696     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
697     unsigned NewWidth = SrcVT.getStoreSizeInBits();
698     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
699     SDValue Ch;
700 
701     // The extra bits are guaranteed to be zero, since we stored them that
702     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
703 
704     ISD::LoadExtType NewExtType =
705       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
706 
707     SDValue Result =
708       DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
709                      Chain, Ptr, LD->getPointerInfo(),
710                      NVT, isVolatile, isNonTemporal, isInvariant, Alignment,
711                      AAInfo);
712 
713     Ch = Result.getValue(1); // The chain.
714 
715     if (ExtType == ISD::SEXTLOAD)
716       // Having the top bits zero doesn't help when sign extending.
717       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
718                            Result.getValueType(),
719                            Result, DAG.getValueType(SrcVT));
720     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
721       // All the top bits are guaranteed to be zero - inform the optimizers.
722       Result = DAG.getNode(ISD::AssertZext, dl,
723                            Result.getValueType(), Result,
724                            DAG.getValueType(SrcVT));
725 
726     Value = Result;
727     Chain = Ch;
728   } else if (SrcWidth & (SrcWidth - 1)) {
729     // If not loading a power-of-2 number of bits, expand as two loads.
730     assert(!SrcVT.isVector() && "Unsupported extload!");
731     unsigned RoundWidth = 1 << Log2_32(SrcWidth);
732     assert(RoundWidth < SrcWidth);
733     unsigned ExtraWidth = SrcWidth - RoundWidth;
734     assert(ExtraWidth < RoundWidth);
735     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
736            "Load size not an integral number of bytes!");
737     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
738     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
739     SDValue Lo, Hi, Ch;
740     unsigned IncrementSize;
741     auto &DL = DAG.getDataLayout();
742 
743     if (DL.isLittleEndian()) {
744       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
745       // Load the bottom RoundWidth bits.
746       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0),
747                           Chain, Ptr,
748                           LD->getPointerInfo(), RoundVT, isVolatile,
749                           isNonTemporal, isInvariant, Alignment, AAInfo);
750 
751       // Load the remaining ExtraWidth bits.
752       IncrementSize = RoundWidth / 8;
753       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
754                          DAG.getConstant(IncrementSize, dl,
755                                          Ptr.getValueType()));
756       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
757                           LD->getPointerInfo().getWithOffset(IncrementSize),
758                           ExtraVT, isVolatile, isNonTemporal, isInvariant,
759                           MinAlign(Alignment, IncrementSize), AAInfo);
760 
761       // Build a factor node to remember that this load is independent of
762       // the other one.
763       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
764                        Hi.getValue(1));
765 
766       // Move the top bits to the right place.
767       Hi = DAG.getNode(
768           ISD::SHL, dl, Hi.getValueType(), Hi,
769           DAG.getConstant(RoundWidth, dl,
770                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
771 
772       // Join the hi and lo parts.
773       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
774     } else {
775       // Big endian - avoid unaligned loads.
776       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
777       // Load the top RoundWidth bits.
778       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
779                           LD->getPointerInfo(), RoundVT, isVolatile,
780                           isNonTemporal, isInvariant, Alignment, AAInfo);
781 
782       // Load the remaining ExtraWidth bits.
783       IncrementSize = RoundWidth / 8;
784       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
785                          DAG.getConstant(IncrementSize, dl,
786                                          Ptr.getValueType()));
787       Lo = DAG.getExtLoad(ISD::ZEXTLOAD,
788                           dl, Node->getValueType(0), Chain, Ptr,
789                           LD->getPointerInfo().getWithOffset(IncrementSize),
790                           ExtraVT, isVolatile, isNonTemporal, isInvariant,
791                           MinAlign(Alignment, IncrementSize), AAInfo);
792 
793       // Build a factor node to remember that this load is independent of
794       // the other one.
795       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
796                        Hi.getValue(1));
797 
798       // Move the top bits to the right place.
799       Hi = DAG.getNode(
800           ISD::SHL, dl, Hi.getValueType(), Hi,
801           DAG.getConstant(ExtraWidth, dl,
802                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
803 
804       // Join the hi and lo parts.
805       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
806     }
807 
808     Chain = Ch;
809   } else {
810     bool isCustom = false;
811     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
812                                  SrcVT.getSimpleVT())) {
813     default: llvm_unreachable("This action is not supported yet!");
814     case TargetLowering::Custom:
815       isCustom = true;
816       // FALLTHROUGH
817     case TargetLowering::Legal: {
818       Value = SDValue(Node, 0);
819       Chain = SDValue(Node, 1);
820 
821       if (isCustom) {
822         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
823           Value = Res;
824           Chain = Res.getValue(1);
825         }
826       } else {
827         // If this is an unaligned load and the target doesn't support it,
828         // expand it.
829         EVT MemVT = LD->getMemoryVT();
830         unsigned AS = LD->getAddressSpace();
831         unsigned Align = LD->getAlignment();
832         const DataLayout &DL = DAG.getDataLayout();
833         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT, AS, Align)) {
834           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
835         }
836       }
837       break;
838     }
839     case TargetLowering::Expand:
840       EVT DestVT = Node->getValueType(0);
841       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
842         // If the source type is not legal, see if there is a legal extload to
843         // an intermediate type that we can then extend further.
844         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
845         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
846             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
847           // If we are loading a legal type, this is a non-extload followed by a
848           // full extend.
849           ISD::LoadExtType MidExtType =
850               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
851 
852           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
853                                         SrcVT, LD->getMemOperand());
854           unsigned ExtendOp =
855               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
856           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
857           Chain = Load.getValue(1);
858           break;
859         }
860 
861         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
862         // normal undefined upper bits behavior to allow using an in-reg extend
863         // with the illegal FP type, so load as an integer and do the
864         // from-integer conversion.
865         if (SrcVT.getScalarType() == MVT::f16) {
866           EVT ISrcVT = SrcVT.changeTypeToInteger();
867           EVT IDestVT = DestVT.changeTypeToInteger();
868           EVT LoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
869 
870           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, LoadVT,
871                                           Chain, Ptr, ISrcVT,
872                                           LD->getMemOperand());
873           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
874           Chain = Result.getValue(1);
875           break;
876         }
877       }
878 
879       assert(!SrcVT.isVector() &&
880              "Vector Loads are handled in LegalizeVectorOps");
881 
882       // FIXME: This does not work for vectors on most targets.  Sign-
883       // and zero-extend operations are currently folded into extending
884       // loads, whether they are legal or not, and then we end up here
885       // without any support for legalizing them.
886       assert(ExtType != ISD::EXTLOAD &&
887              "EXTLOAD should always be supported!");
888       // Turn the unsupported load into an EXTLOAD followed by an
889       // explicit zero/sign extend inreg.
890       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
891                                       Node->getValueType(0),
892                                       Chain, Ptr, SrcVT,
893                                       LD->getMemOperand());
894       SDValue ValRes;
895       if (ExtType == ISD::SEXTLOAD)
896         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
897                              Result.getValueType(),
898                              Result, DAG.getValueType(SrcVT));
899       else
900         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
901       Value = ValRes;
902       Chain = Result.getValue(1);
903       break;
904     }
905   }
906 
907   // Since loads produce two values, make sure to remember that we legalized
908   // both of them.
909   if (Chain.getNode() != Node) {
910     assert(Value.getNode() != Node && "Load must be completely replaced");
911     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
912     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
913     if (UpdatedNodes) {
914       UpdatedNodes->insert(Value.getNode());
915       UpdatedNodes->insert(Chain.getNode());
916     }
917     ReplacedNode(Node);
918   }
919 }
920 
921 /// Return a legal replacement for the given operation, with all legal operands.
LegalizeOp(SDNode * Node)922 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
923   DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
924 
925   if (Node->getOpcode() == ISD::TargetConstant) // Allow illegal target nodes.
926     return;
927 
928 #ifndef NDEBUG
929   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
930     assert((TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
931               TargetLowering::TypeLegal ||
932             TLI.isTypeLegal(Node->getValueType(i))) &&
933            "Unexpected illegal type!");
934 
935   for (const SDValue &Op : Node->op_values())
936     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
937               TargetLowering::TypeLegal ||
938             TLI.isTypeLegal(Op.getValueType()) ||
939             Op.getOpcode() == ISD::TargetConstant) &&
940             "Unexpected illegal type!");
941 #endif
942 
943   // Figure out the correct action; the way to query this varies by opcode
944   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
945   bool SimpleFinishLegalizing = true;
946   switch (Node->getOpcode()) {
947   case ISD::INTRINSIC_W_CHAIN:
948   case ISD::INTRINSIC_WO_CHAIN:
949   case ISD::INTRINSIC_VOID:
950   case ISD::STACKSAVE:
951     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
952     break;
953   case ISD::GET_DYNAMIC_AREA_OFFSET:
954     Action = TLI.getOperationAction(Node->getOpcode(),
955                                     Node->getValueType(0));
956     break;
957   case ISD::VAARG:
958     Action = TLI.getOperationAction(Node->getOpcode(),
959                                     Node->getValueType(0));
960     if (Action != TargetLowering::Promote)
961       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
962     break;
963   case ISD::FP_TO_FP16:
964   case ISD::SINT_TO_FP:
965   case ISD::UINT_TO_FP:
966   case ISD::EXTRACT_VECTOR_ELT:
967     Action = TLI.getOperationAction(Node->getOpcode(),
968                                     Node->getOperand(0).getValueType());
969     break;
970   case ISD::FP_ROUND_INREG:
971   case ISD::SIGN_EXTEND_INREG: {
972     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
973     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
974     break;
975   }
976   case ISD::ATOMIC_STORE: {
977     Action = TLI.getOperationAction(Node->getOpcode(),
978                                     Node->getOperand(2).getValueType());
979     break;
980   }
981   case ISD::SELECT_CC:
982   case ISD::SETCC:
983   case ISD::BR_CC: {
984     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
985                          Node->getOpcode() == ISD::SETCC ? 2 :
986                          Node->getOpcode() == ISD::SETCCE ? 3 : 1;
987     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
988     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
989     ISD::CondCode CCCode =
990         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
991     Action = TLI.getCondCodeAction(CCCode, OpVT);
992     if (Action == TargetLowering::Legal) {
993       if (Node->getOpcode() == ISD::SELECT_CC)
994         Action = TLI.getOperationAction(Node->getOpcode(),
995                                         Node->getValueType(0));
996       else
997         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
998     }
999     break;
1000   }
1001   case ISD::LOAD:
1002   case ISD::STORE:
1003     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1004     // STORE expects the unlegalized operand in some cases.
1005     SimpleFinishLegalizing = false;
1006     break;
1007   case ISD::CALLSEQ_START:
1008   case ISD::CALLSEQ_END:
1009     // FIXME: This shouldn't be necessary.  These nodes have special properties
1010     // dealing with the recursive nature of legalization.  Removing this
1011     // special case should be done as part of making LegalizeDAG non-recursive.
1012     SimpleFinishLegalizing = false;
1013     break;
1014   case ISD::EXTRACT_ELEMENT:
1015   case ISD::FLT_ROUNDS_:
1016   case ISD::FPOWI:
1017   case ISD::MERGE_VALUES:
1018   case ISD::EH_RETURN:
1019   case ISD::FRAME_TO_ARGS_OFFSET:
1020   case ISD::EH_SJLJ_SETJMP:
1021   case ISD::EH_SJLJ_LONGJMP:
1022   case ISD::EH_SJLJ_SETUP_DISPATCH:
1023     // These operations lie about being legal: when they claim to be legal,
1024     // they should actually be expanded.
1025     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1026     if (Action == TargetLowering::Legal)
1027       Action = TargetLowering::Expand;
1028     break;
1029   case ISD::INIT_TRAMPOLINE:
1030   case ISD::ADJUST_TRAMPOLINE:
1031   case ISD::FRAMEADDR:
1032   case ISD::RETURNADDR:
1033     // These operations lie about being legal: when they claim to be legal,
1034     // they should actually be custom-lowered.
1035     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1036     if (Action == TargetLowering::Legal)
1037       Action = TargetLowering::Custom;
1038     break;
1039   case ISD::READCYCLECOUNTER:
1040     // READCYCLECOUNTER returns an i64, even if type legalization might have
1041     // expanded that to several smaller types.
1042     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1043     break;
1044   case ISD::READ_REGISTER:
1045   case ISD::WRITE_REGISTER:
1046     // Named register is legal in the DAG, but blocked by register name
1047     // selection if not implemented by target (to chose the correct register)
1048     // They'll be converted to Copy(To/From)Reg.
1049     Action = TargetLowering::Legal;
1050     break;
1051   case ISD::DEBUGTRAP:
1052     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1053     if (Action == TargetLowering::Expand) {
1054       // replace ISD::DEBUGTRAP with ISD::TRAP
1055       SDValue NewVal;
1056       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1057                            Node->getOperand(0));
1058       ReplaceNode(Node, NewVal.getNode());
1059       LegalizeOp(NewVal.getNode());
1060       return;
1061     }
1062     break;
1063 
1064   default:
1065     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1066       Action = TargetLowering::Legal;
1067     } else {
1068       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1069     }
1070     break;
1071   }
1072 
1073   if (SimpleFinishLegalizing) {
1074     SDNode *NewNode = Node;
1075     switch (Node->getOpcode()) {
1076     default: break;
1077     case ISD::SHL:
1078     case ISD::SRL:
1079     case ISD::SRA:
1080     case ISD::ROTL:
1081     case ISD::ROTR:
1082       // Legalizing shifts/rotates requires adjusting the shift amount
1083       // to the appropriate width.
1084       if (!Node->getOperand(1).getValueType().isVector()) {
1085         SDValue SAO =
1086           DAG.getShiftAmountOperand(Node->getOperand(0).getValueType(),
1087                                     Node->getOperand(1));
1088         HandleSDNode Handle(SAO);
1089         LegalizeOp(SAO.getNode());
1090         NewNode = DAG.UpdateNodeOperands(Node, Node->getOperand(0),
1091                                          Handle.getValue());
1092       }
1093       break;
1094     case ISD::SRL_PARTS:
1095     case ISD::SRA_PARTS:
1096     case ISD::SHL_PARTS:
1097       // Legalizing shifts/rotates requires adjusting the shift amount
1098       // to the appropriate width.
1099       if (!Node->getOperand(2).getValueType().isVector()) {
1100         SDValue SAO =
1101           DAG.getShiftAmountOperand(Node->getOperand(0).getValueType(),
1102                                     Node->getOperand(2));
1103         HandleSDNode Handle(SAO);
1104         LegalizeOp(SAO.getNode());
1105         NewNode = DAG.UpdateNodeOperands(Node, Node->getOperand(0),
1106                                          Node->getOperand(1),
1107                                          Handle.getValue());
1108       }
1109       break;
1110     }
1111 
1112     if (NewNode != Node) {
1113       ReplaceNode(Node, NewNode);
1114       Node = NewNode;
1115     }
1116     switch (Action) {
1117     case TargetLowering::Legal:
1118       return;
1119     case TargetLowering::Custom: {
1120       // FIXME: The handling for custom lowering with multiple results is
1121       // a complete mess.
1122       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1123         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1124           return;
1125 
1126         if (Node->getNumValues() == 1) {
1127           // We can just directly replace this node with the lowered value.
1128           ReplaceNode(SDValue(Node, 0), Res);
1129           return;
1130         }
1131 
1132         SmallVector<SDValue, 8> ResultVals;
1133         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1134           ResultVals.push_back(Res.getValue(i));
1135         ReplaceNode(Node, ResultVals.data());
1136         return;
1137       }
1138     }
1139       // FALL THROUGH
1140     case TargetLowering::Expand:
1141       if (ExpandNode(Node))
1142         return;
1143       // FALL THROUGH
1144     case TargetLowering::LibCall:
1145       ConvertNodeToLibcall(Node);
1146       return;
1147     case TargetLowering::Promote:
1148       PromoteNode(Node);
1149       return;
1150     }
1151   }
1152 
1153   switch (Node->getOpcode()) {
1154   default:
1155 #ifndef NDEBUG
1156     dbgs() << "NODE: ";
1157     Node->dump( &DAG);
1158     dbgs() << "\n";
1159 #endif
1160     llvm_unreachable("Do not know how to legalize this operator!");
1161 
1162   case ISD::CALLSEQ_START:
1163   case ISD::CALLSEQ_END:
1164     break;
1165   case ISD::LOAD: {
1166     return LegalizeLoadOps(Node);
1167   }
1168   case ISD::STORE: {
1169     return LegalizeStoreOps(Node);
1170   }
1171   }
1172 }
1173 
ExpandExtractFromVectorThroughStack(SDValue Op)1174 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1175   SDValue Vec = Op.getOperand(0);
1176   SDValue Idx = Op.getOperand(1);
1177   SDLoc dl(Op);
1178 
1179   // Before we generate a new store to a temporary stack slot, see if there is
1180   // already one that we can use. There often is because when we scalarize
1181   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1182   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1183   // the vector. If all are expanded here, we don't want one store per vector
1184   // element.
1185 
1186   // Caches for hasPredecessorHelper
1187   SmallPtrSet<const SDNode *, 32> Visited;
1188   SmallVector<const SDNode *, 16> Worklist;
1189   Worklist.push_back(Idx.getNode());
1190   SDValue StackPtr, Ch;
1191   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1192        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1193     SDNode *User = *UI;
1194     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1195       if (ST->isIndexed() || ST->isTruncatingStore() ||
1196           ST->getValue() != Vec)
1197         continue;
1198 
1199       // Make sure that nothing else could have stored into the destination of
1200       // this store.
1201       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1202         continue;
1203 
1204       // If the index is dependent on the store we will introduce a cycle when
1205       // creating the load (the load uses the index, and by replacing the chain
1206       // we will make the index dependent on the load).
1207       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist))
1208         continue;
1209 
1210       StackPtr = ST->getBasePtr();
1211       Ch = SDValue(ST, 0);
1212       break;
1213     }
1214   }
1215 
1216   if (!Ch.getNode()) {
1217     // Store the value to a temporary stack slot, then LOAD the returned part.
1218     StackPtr = DAG.CreateStackTemporary(Vec.getValueType());
1219     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1220                       MachinePointerInfo(), false, false, 0);
1221   }
1222 
1223   // Add the offset to the index.
1224   unsigned EltSize =
1225       Vec.getValueType().getVectorElementType().getSizeInBits()/8;
1226   Idx = DAG.getNode(ISD::MUL, dl, Idx.getValueType(), Idx,
1227                     DAG.getConstant(EltSize, SDLoc(Vec), Idx.getValueType()));
1228 
1229   Idx = DAG.getZExtOrTrunc(Idx, dl, TLI.getPointerTy(DAG.getDataLayout()));
1230   StackPtr = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, StackPtr);
1231 
1232   SDValue NewLoad;
1233 
1234   if (Op.getValueType().isVector())
1235     NewLoad = DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr,
1236                           MachinePointerInfo(), false, false, false, 0);
1237   else
1238     NewLoad = DAG.getExtLoad(
1239         ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr, MachinePointerInfo(),
1240         Vec.getValueType().getVectorElementType(), false, false, false, 0);
1241 
1242   // Replace the chain going out of the store, by the one out of the load.
1243   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1244 
1245   // We introduced a cycle though, so update the loads operands, making sure
1246   // to use the original store's chain as an incoming chain.
1247   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1248                                           NewLoad->op_end());
1249   NewLoadOperands[0] = Ch;
1250   NewLoad =
1251       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1252   return NewLoad;
1253 }
1254 
ExpandInsertToVectorThroughStack(SDValue Op)1255 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1256   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1257 
1258   SDValue Vec  = Op.getOperand(0);
1259   SDValue Part = Op.getOperand(1);
1260   SDValue Idx  = Op.getOperand(2);
1261   SDLoc dl(Op);
1262 
1263   // Store the value to a temporary stack slot, then LOAD the returned part.
1264 
1265   SDValue StackPtr = DAG.CreateStackTemporary(Vec.getValueType());
1266   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1267   MachinePointerInfo PtrInfo =
1268       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1269 
1270   // First store the whole vector.
1271   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo,
1272                             false, false, 0);
1273 
1274   // Then store the inserted part.
1275 
1276   // Add the offset to the index.
1277   unsigned EltSize =
1278       Vec.getValueType().getVectorElementType().getSizeInBits()/8;
1279 
1280   Idx = DAG.getNode(ISD::MUL, dl, Idx.getValueType(), Idx,
1281                     DAG.getConstant(EltSize, SDLoc(Vec), Idx.getValueType()));
1282   Idx = DAG.getZExtOrTrunc(Idx, dl, TLI.getPointerTy(DAG.getDataLayout()));
1283 
1284   SDValue SubStackPtr = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
1285                                     StackPtr);
1286 
1287   // Store the subvector.
1288   Ch = DAG.getStore(Ch, dl, Part, SubStackPtr,
1289                     MachinePointerInfo(), false, false, 0);
1290 
1291   // Finally, load the updated vector.
1292   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo,
1293                      false, false, false, 0);
1294 }
1295 
ExpandVectorBuildThroughStack(SDNode * Node)1296 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1297   // We can't handle this case efficiently.  Allocate a sufficiently
1298   // aligned object on the stack, store each element into it, then load
1299   // the result as a vector.
1300   // Create the stack frame object.
1301   EVT VT = Node->getValueType(0);
1302   EVT EltVT = VT.getVectorElementType();
1303   SDLoc dl(Node);
1304   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1305   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1306   MachinePointerInfo PtrInfo =
1307       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1308 
1309   // Emit a store of each element to the stack slot.
1310   SmallVector<SDValue, 8> Stores;
1311   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
1312   // Store (in the right endianness) the elements to memory.
1313   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1314     // Ignore undef elements.
1315     if (Node->getOperand(i).isUndef()) continue;
1316 
1317     unsigned Offset = TypeByteSize*i;
1318 
1319     SDValue Idx = DAG.getConstant(Offset, dl, FIPtr.getValueType());
1320     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
1321 
1322     // If the destination vector element type is narrower than the source
1323     // element type, only store the bits necessary.
1324     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
1325       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1326                                          Node->getOperand(i), Idx,
1327                                          PtrInfo.getWithOffset(Offset),
1328                                          EltVT, false, false, 0));
1329     } else
1330       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl,
1331                                     Node->getOperand(i), Idx,
1332                                     PtrInfo.getWithOffset(Offset),
1333                                     false, false, 0));
1334   }
1335 
1336   SDValue StoreChain;
1337   if (!Stores.empty())    // Not all undef elements?
1338     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1339   else
1340     StoreChain = DAG.getEntryNode();
1341 
1342   // Result is a load from the stack slot.
1343   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo,
1344                      false, false, false, 0);
1345 }
1346 
1347 namespace {
1348 /// Keeps track of state when getting the sign of a floating-point value as an
1349 /// integer.
1350 struct FloatSignAsInt {
1351   EVT FloatVT;
1352   SDValue Chain;
1353   SDValue FloatPtr;
1354   SDValue IntPtr;
1355   MachinePointerInfo IntPointerInfo;
1356   MachinePointerInfo FloatPointerInfo;
1357   SDValue IntValue;
1358   APInt SignMask;
1359   uint8_t SignBit;
1360 };
1361 }
1362 
1363 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1364 /// containing the sign bit if the target has no integer value capable of
1365 /// holding all bits of the floating-point value.
getSignAsIntValue(FloatSignAsInt & State,const SDLoc & DL,SDValue Value) const1366 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1367                                              const SDLoc &DL,
1368                                              SDValue Value) const {
1369   EVT FloatVT = Value.getValueType();
1370   unsigned NumBits = FloatVT.getSizeInBits();
1371   State.FloatVT = FloatVT;
1372   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1373   // Convert to an integer of the same size.
1374   if (TLI.isTypeLegal(IVT)) {
1375     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1376     State.SignMask = APInt::getSignBit(NumBits);
1377     State.SignBit = NumBits - 1;
1378     return;
1379   }
1380 
1381   auto &DataLayout = DAG.getDataLayout();
1382   // Store the float to memory, then load the sign part out as an integer.
1383   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1384   // First create a temporary that is aligned for both the load and store.
1385   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1386   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1387   // Then store the float to it.
1388   State.FloatPtr = StackPtr;
1389   MachineFunction &MF = DAG.getMachineFunction();
1390   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1391   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1392                              State.FloatPointerInfo, false, false, 0);
1393 
1394   SDValue IntPtr;
1395   if (DataLayout.isBigEndian()) {
1396     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1397     // Load out a legal integer with the same sign bit as the float.
1398     IntPtr = StackPtr;
1399     State.IntPointerInfo = State.FloatPointerInfo;
1400   } else {
1401     // Advance the pointer so that the loaded byte will contain the sign bit.
1402     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1403     IntPtr = DAG.getNode(ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
1404                       DAG.getConstant(ByteOffset, DL, StackPtr.getValueType()));
1405     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1406                                                              ByteOffset);
1407   }
1408 
1409   State.IntPtr = IntPtr;
1410   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain,
1411                                   IntPtr, State.IntPointerInfo, MVT::i8,
1412                                   false, false, false, 0);
1413   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1414   State.SignBit = 7;
1415 }
1416 
1417 /// Replace the integer value produced by getSignAsIntValue() with a new value
1418 /// and cast the result back to a floating-point type.
modifySignAsInt(const FloatSignAsInt & State,const SDLoc & DL,SDValue NewIntValue) const1419 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1420                                               const SDLoc &DL,
1421                                               SDValue NewIntValue) const {
1422   if (!State.Chain)
1423     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1424 
1425   // Override the part containing the sign bit in the value stored on the stack.
1426   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1427                                     State.IntPointerInfo, MVT::i8, false, false,
1428                                     0);
1429   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1430                      State.FloatPointerInfo, false, false, false, 0);
1431 }
1432 
ExpandFCOPYSIGN(SDNode * Node) const1433 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1434   SDLoc DL(Node);
1435   SDValue Mag = Node->getOperand(0);
1436   SDValue Sign = Node->getOperand(1);
1437 
1438   // Get sign bit into an integer value.
1439   FloatSignAsInt SignAsInt;
1440   getSignAsIntValue(SignAsInt, DL, Sign);
1441 
1442   EVT IntVT = SignAsInt.IntValue.getValueType();
1443   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1444   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1445                                 SignMask);
1446 
1447   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1448   EVT FloatVT = Mag.getValueType();
1449   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1450       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1451     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1452     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1453     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1454                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1455     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1456   }
1457 
1458   // Transform Mag value to integer, and clear the sign bit.
1459   FloatSignAsInt MagAsInt;
1460   getSignAsIntValue(MagAsInt, DL, Mag);
1461   EVT MagVT = MagAsInt.IntValue.getValueType();
1462   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1463   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1464                                     ClearSignMask);
1465 
1466   // Get the signbit at the right position for MagAsInt.
1467   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1468   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1469     if (ShiftAmount > 0) {
1470       SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, IntVT);
1471       SignBit = DAG.getNode(ISD::SRL, DL, IntVT, SignBit, ShiftCnst);
1472     } else if (ShiftAmount < 0) {
1473       SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, IntVT);
1474       SignBit = DAG.getNode(ISD::SHL, DL, IntVT, SignBit, ShiftCnst);
1475     }
1476     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1477   } else if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1478     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1479     if (ShiftAmount > 0) {
1480       SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, MagVT);
1481       SignBit = DAG.getNode(ISD::SRL, DL, MagVT, SignBit, ShiftCnst);
1482     } else if (ShiftAmount < 0) {
1483       SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, MagVT);
1484       SignBit = DAG.getNode(ISD::SHL, DL, MagVT, SignBit, ShiftCnst);
1485     }
1486   }
1487 
1488   // Store the part with the modified sign and convert back to float.
1489   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1490   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1491 }
1492 
ExpandFABS(SDNode * Node) const1493 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1494   SDLoc DL(Node);
1495   SDValue Value = Node->getOperand(0);
1496 
1497   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1498   EVT FloatVT = Value.getValueType();
1499   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1500     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1501     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1502   }
1503 
1504   // Transform value to integer, clear the sign bit and transform back.
1505   FloatSignAsInt ValueAsInt;
1506   getSignAsIntValue(ValueAsInt, DL, Value);
1507   EVT IntVT = ValueAsInt.IntValue.getValueType();
1508   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1509   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1510                                     ClearSignMask);
1511   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1512 }
1513 
ExpandDYNAMIC_STACKALLOC(SDNode * Node,SmallVectorImpl<SDValue> & Results)1514 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1515                                            SmallVectorImpl<SDValue> &Results) {
1516   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1517   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1518           " not tell us which reg is the stack pointer!");
1519   SDLoc dl(Node);
1520   EVT VT = Node->getValueType(0);
1521   SDValue Tmp1 = SDValue(Node, 0);
1522   SDValue Tmp2 = SDValue(Node, 1);
1523   SDValue Tmp3 = Node->getOperand(2);
1524   SDValue Chain = Tmp1.getOperand(0);
1525 
1526   // Chain the dynamic stack allocation so that it doesn't modify the stack
1527   // pointer when other instructions are using the stack.
1528   Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(0, dl, true), dl);
1529 
1530   SDValue Size  = Tmp2.getOperand(1);
1531   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1532   Chain = SP.getValue(1);
1533   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
1534   unsigned StackAlign =
1535       DAG.getSubtarget().getFrameLowering()->getStackAlignment();
1536   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
1537   if (Align > StackAlign)
1538     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1539                        DAG.getConstant(-(uint64_t)Align, dl, VT));
1540   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1541 
1542   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1543                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1544 
1545   Results.push_back(Tmp1);
1546   Results.push_back(Tmp2);
1547 }
1548 
1549 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1550 /// target.
1551 ///
1552 /// If the SETCC has been legalized using AND / OR, then the legalized node
1553 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1554 /// will be set to false.
1555 ///
1556 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1557 /// then the values of LHS and RHS will be swapped, CC will be set to the
1558 /// new condition, and NeedInvert will be set to false.
1559 ///
1560 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1561 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1562 /// will be set to true. The caller must invert the result of the SETCC with
1563 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1564 /// of a true/false result.
1565 ///
1566 /// \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)1567 bool SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT, SDValue &LHS,
1568                                                  SDValue &RHS, SDValue &CC,
1569                                                  bool &NeedInvert,
1570                                                  const SDLoc &dl) {
1571   MVT OpVT = LHS.getSimpleValueType();
1572   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1573   NeedInvert = false;
1574   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1575   default: llvm_unreachable("Unknown condition code action!");
1576   case TargetLowering::Legal:
1577     // Nothing to do.
1578     break;
1579   case TargetLowering::Expand: {
1580     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1581     if (TLI.isCondCodeLegal(InvCC, OpVT)) {
1582       std::swap(LHS, RHS);
1583       CC = DAG.getCondCode(InvCC);
1584       return true;
1585     }
1586     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1587     unsigned Opc = 0;
1588     switch (CCCode) {
1589     default: llvm_unreachable("Don't know how to expand this condition!");
1590     case ISD::SETO:
1591         assert(TLI.getCondCodeAction(ISD::SETOEQ, OpVT)
1592             == TargetLowering::Legal
1593             && "If SETO is expanded, SETOEQ must be legal!");
1594         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1595     case ISD::SETUO:
1596         assert(TLI.getCondCodeAction(ISD::SETUNE, OpVT)
1597             == TargetLowering::Legal
1598             && "If SETUO is expanded, SETUNE must be legal!");
1599         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1600     case ISD::SETOEQ:
1601     case ISD::SETOGT:
1602     case ISD::SETOGE:
1603     case ISD::SETOLT:
1604     case ISD::SETOLE:
1605     case ISD::SETONE:
1606     case ISD::SETUEQ:
1607     case ISD::SETUNE:
1608     case ISD::SETUGT:
1609     case ISD::SETUGE:
1610     case ISD::SETULT:
1611     case ISD::SETULE:
1612         // If we are floating point, assign and break, otherwise fall through.
1613         if (!OpVT.isInteger()) {
1614           // We can use the 4th bit to tell if we are the unordered
1615           // or ordered version of the opcode.
1616           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1617           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1618           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1619           break;
1620         }
1621         // Fallthrough if we are unsigned integer.
1622     case ISD::SETLE:
1623     case ISD::SETGT:
1624     case ISD::SETGE:
1625     case ISD::SETLT:
1626       // We only support using the inverted operation, which is computed above
1627       // and not a different manner of supporting expanding these cases.
1628       llvm_unreachable("Don't know how to expand this condition!");
1629     case ISD::SETNE:
1630     case ISD::SETEQ:
1631       // Try inverting the result of the inverse condition.
1632       InvCC = CCCode == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ;
1633       if (TLI.isCondCodeLegal(InvCC, OpVT)) {
1634         CC = DAG.getCondCode(InvCC);
1635         NeedInvert = true;
1636         return true;
1637       }
1638       // If inverting the condition didn't work then we have no means to expand
1639       // the condition.
1640       llvm_unreachable("Don't know how to expand this condition!");
1641     }
1642 
1643     SDValue SetCC1, SetCC2;
1644     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1645       // If we aren't the ordered or unorder operation,
1646       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1647       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
1648       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
1649     } else {
1650       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1651       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1);
1652       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2);
1653     }
1654     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1655     RHS = SDValue();
1656     CC  = SDValue();
1657     return true;
1658   }
1659   }
1660   return false;
1661 }
1662 
1663 /// Emit a store/load combination to the stack.  This stores
1664 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1665 /// a load from the stack slot to DestVT, extending it if needed.
1666 /// The resultant code need not be legal.
EmitStackConvert(SDValue SrcOp,EVT SlotVT,EVT DestVT,const SDLoc & dl)1667 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1668                                                EVT DestVT, const SDLoc &dl) {
1669   // Create the stack frame object.
1670   unsigned SrcAlign = DAG.getDataLayout().getPrefTypeAlignment(
1671       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1672   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
1673 
1674   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1675   int SPFI = StackPtrFI->getIndex();
1676   MachinePointerInfo PtrInfo =
1677       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1678 
1679   unsigned SrcSize = SrcOp.getValueType().getSizeInBits();
1680   unsigned SlotSize = SlotVT.getSizeInBits();
1681   unsigned DestSize = DestVT.getSizeInBits();
1682   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1683   unsigned DestAlign = DAG.getDataLayout().getPrefTypeAlignment(DestType);
1684 
1685   // Emit a store to the stack slot.  Use a truncstore if the input value is
1686   // later than DestVT.
1687   SDValue Store;
1688 
1689   if (SrcSize > SlotSize)
1690     Store = DAG.getTruncStore(DAG.getEntryNode(), dl, SrcOp, FIPtr,
1691                               PtrInfo, SlotVT, false, false, SrcAlign);
1692   else {
1693     assert(SrcSize == SlotSize && "Invalid store");
1694     Store = DAG.getStore(DAG.getEntryNode(), dl, SrcOp, FIPtr,
1695                          PtrInfo, false, false, SrcAlign);
1696   }
1697 
1698   // Result is a load from the stack slot.
1699   if (SlotSize == DestSize)
1700     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo,
1701                        false, false, false, DestAlign);
1702 
1703   assert(SlotSize < DestSize && "Unknown extension!");
1704   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr,
1705                         PtrInfo, SlotVT, false, false, false, DestAlign);
1706 }
1707 
ExpandSCALAR_TO_VECTOR(SDNode * Node)1708 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1709   SDLoc dl(Node);
1710   // Create a vector sized/aligned stack slot, store the value to element #0,
1711   // then load the whole vector back out.
1712   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1713 
1714   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1715   int SPFI = StackPtrFI->getIndex();
1716 
1717   SDValue Ch = DAG.getTruncStore(
1718       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1719       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1720       Node->getValueType(0).getVectorElementType(), false, false, 0);
1721   return DAG.getLoad(
1722       Node->getValueType(0), dl, Ch, StackPtr,
1723       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI), false,
1724       false, false, 0);
1725 }
1726 
1727 static bool
ExpandBVWithShuffles(SDNode * Node,SelectionDAG & DAG,const TargetLowering & TLI,SDValue & Res)1728 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1729                      const TargetLowering &TLI, SDValue &Res) {
1730   unsigned NumElems = Node->getNumOperands();
1731   SDLoc dl(Node);
1732   EVT VT = Node->getValueType(0);
1733 
1734   // Try to group the scalars into pairs, shuffle the pairs together, then
1735   // shuffle the pairs of pairs together, etc. until the vector has
1736   // been built. This will work only if all of the necessary shuffle masks
1737   // are legal.
1738 
1739   // We do this in two phases; first to check the legality of the shuffles,
1740   // and next, assuming that all shuffles are legal, to create the new nodes.
1741   for (int Phase = 0; Phase < 2; ++Phase) {
1742     SmallVector<std::pair<SDValue, SmallVector<int, 16> >, 16> IntermedVals,
1743                                                                NewIntermedVals;
1744     for (unsigned i = 0; i < NumElems; ++i) {
1745       SDValue V = Node->getOperand(i);
1746       if (V.isUndef())
1747         continue;
1748 
1749       SDValue Vec;
1750       if (Phase)
1751         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1752       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1753     }
1754 
1755     while (IntermedVals.size() > 2) {
1756       NewIntermedVals.clear();
1757       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1758         // This vector and the next vector are shuffled together (simply to
1759         // append the one to the other).
1760         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1761 
1762         SmallVector<int, 16> FinalIndices;
1763         FinalIndices.reserve(IntermedVals[i].second.size() +
1764                              IntermedVals[i+1].second.size());
1765 
1766         int k = 0;
1767         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1768              ++j, ++k) {
1769           ShuffleVec[k] = j;
1770           FinalIndices.push_back(IntermedVals[i].second[j]);
1771         }
1772         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1773              ++j, ++k) {
1774           ShuffleVec[k] = NumElems + j;
1775           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1776         }
1777 
1778         SDValue Shuffle;
1779         if (Phase)
1780           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1781                                          IntermedVals[i+1].first,
1782                                          ShuffleVec);
1783         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1784           return false;
1785         NewIntermedVals.push_back(
1786             std::make_pair(Shuffle, std::move(FinalIndices)));
1787       }
1788 
1789       // If we had an odd number of defined values, then append the last
1790       // element to the array of new vectors.
1791       if ((IntermedVals.size() & 1) != 0)
1792         NewIntermedVals.push_back(IntermedVals.back());
1793 
1794       IntermedVals.swap(NewIntermedVals);
1795     }
1796 
1797     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1798            "Invalid number of intermediate vectors");
1799     SDValue Vec1 = IntermedVals[0].first;
1800     SDValue Vec2;
1801     if (IntermedVals.size() > 1)
1802       Vec2 = IntermedVals[1].first;
1803     else if (Phase)
1804       Vec2 = DAG.getUNDEF(VT);
1805 
1806     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1807     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1808       ShuffleVec[IntermedVals[0].second[i]] = i;
1809     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1810       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1811 
1812     if (Phase)
1813       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1814     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1815       return false;
1816   }
1817 
1818   return true;
1819 }
1820 
1821 /// Expand a BUILD_VECTOR node on targets that don't
1822 /// support the operation, but do support the resultant vector type.
ExpandBUILD_VECTOR(SDNode * Node)1823 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1824   unsigned NumElems = Node->getNumOperands();
1825   SDValue Value1, Value2;
1826   SDLoc dl(Node);
1827   EVT VT = Node->getValueType(0);
1828   EVT OpVT = Node->getOperand(0).getValueType();
1829   EVT EltVT = VT.getVectorElementType();
1830 
1831   // If the only non-undef value is the low element, turn this into a
1832   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1833   bool isOnlyLowElement = true;
1834   bool MoreThanTwoValues = false;
1835   bool isConstant = true;
1836   for (unsigned i = 0; i < NumElems; ++i) {
1837     SDValue V = Node->getOperand(i);
1838     if (V.isUndef())
1839       continue;
1840     if (i > 0)
1841       isOnlyLowElement = false;
1842     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1843       isConstant = false;
1844 
1845     if (!Value1.getNode()) {
1846       Value1 = V;
1847     } else if (!Value2.getNode()) {
1848       if (V != Value1)
1849         Value2 = V;
1850     } else if (V != Value1 && V != Value2) {
1851       MoreThanTwoValues = true;
1852     }
1853   }
1854 
1855   if (!Value1.getNode())
1856     return DAG.getUNDEF(VT);
1857 
1858   if (isOnlyLowElement)
1859     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1860 
1861   // If all elements are constants, create a load from the constant pool.
1862   if (isConstant) {
1863     SmallVector<Constant*, 16> CV;
1864     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1865       if (ConstantFPSDNode *V =
1866           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1867         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1868       } else if (ConstantSDNode *V =
1869                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1870         if (OpVT==EltVT)
1871           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1872         else {
1873           // If OpVT and EltVT don't match, EltVT is not legal and the
1874           // element values have been promoted/truncated earlier.  Undo this;
1875           // we don't want a v16i8 to become a v16i32 for example.
1876           const ConstantInt *CI = V->getConstantIntValue();
1877           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1878                                         CI->getZExtValue()));
1879         }
1880       } else {
1881         assert(Node->getOperand(i).isUndef());
1882         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
1883         CV.push_back(UndefValue::get(OpNTy));
1884       }
1885     }
1886     Constant *CP = ConstantVector::get(CV);
1887     SDValue CPIdx =
1888         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
1889     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
1890     return DAG.getLoad(
1891         VT, dl, DAG.getEntryNode(), CPIdx,
1892         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), false,
1893         false, false, Alignment);
1894   }
1895 
1896   SmallSet<SDValue, 16> DefinedValues;
1897   for (unsigned i = 0; i < NumElems; ++i) {
1898     if (Node->getOperand(i).isUndef())
1899       continue;
1900     DefinedValues.insert(Node->getOperand(i));
1901   }
1902 
1903   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
1904     if (!MoreThanTwoValues) {
1905       SmallVector<int, 8> ShuffleVec(NumElems, -1);
1906       for (unsigned i = 0; i < NumElems; ++i) {
1907         SDValue V = Node->getOperand(i);
1908         if (V.isUndef())
1909           continue;
1910         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
1911       }
1912       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
1913         // Get the splatted value into the low element of a vector register.
1914         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
1915         SDValue Vec2;
1916         if (Value2.getNode())
1917           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
1918         else
1919           Vec2 = DAG.getUNDEF(VT);
1920 
1921         // Return shuffle(LowValVec, undef, <0,0,0,0>)
1922         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1923       }
1924     } else {
1925       SDValue Res;
1926       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
1927         return Res;
1928     }
1929   }
1930 
1931   // Otherwise, we can't handle this case efficiently.
1932   return ExpandVectorBuildThroughStack(Node);
1933 }
1934 
1935 // Expand a node into a call to a libcall.  If the result value
1936 // does not fit into a register, return the lo part and set the hi part to the
1937 // by-reg argument.  If it does fit into a single register, return the result
1938 // and leave the Hi part unset.
ExpandLibCall(RTLIB::Libcall LC,SDNode * Node,bool isSigned)1939 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
1940                                             bool isSigned) {
1941   TargetLowering::ArgListTy Args;
1942   TargetLowering::ArgListEntry Entry;
1943   for (const SDValue &Op : Node->op_values()) {
1944     EVT ArgVT = Op.getValueType();
1945     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1946     Entry.Node = Op;
1947     Entry.Ty = ArgTy;
1948     Entry.isSExt = isSigned;
1949     Entry.isZExt = !isSigned;
1950     Args.push_back(Entry);
1951   }
1952   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1953                                          TLI.getPointerTy(DAG.getDataLayout()));
1954 
1955   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
1956 
1957   // By default, the input chain to this libcall is the entry node of the
1958   // function. If the libcall is going to be emitted as a tail call then
1959   // TLI.isUsedByReturnOnly will change it to the right chain if the return
1960   // node which is being folded has a non-entry input chain.
1961   SDValue InChain = DAG.getEntryNode();
1962 
1963   // isTailCall may be true since the callee does not reference caller stack
1964   // frame. Check if it's in the right position and that the return types match.
1965   SDValue TCChain = InChain;
1966   const Function *F = DAG.getMachineFunction().getFunction();
1967   bool isTailCall =
1968       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
1969       (RetTy == F->getReturnType() || F->getReturnType()->isVoidTy());
1970   if (isTailCall)
1971     InChain = TCChain;
1972 
1973   TargetLowering::CallLoweringInfo CLI(DAG);
1974   CLI.setDebugLoc(SDLoc(Node)).setChain(InChain)
1975     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args))
1976     .setTailCall(isTailCall).setSExtResult(isSigned).setZExtResult(!isSigned);
1977 
1978   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
1979 
1980   if (!CallInfo.second.getNode())
1981     // It's a tailcall, return the chain (which is the DAG root).
1982     return DAG.getRoot();
1983 
1984   return CallInfo.first;
1985 }
1986 
1987 /// Generate a libcall taking the given operands as arguments
1988 /// and returning a result of type RetVT.
ExpandLibCall(RTLIB::Libcall LC,EVT RetVT,const SDValue * Ops,unsigned NumOps,bool isSigned,const SDLoc & dl)1989 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, EVT RetVT,
1990                                             const SDValue *Ops, unsigned NumOps,
1991                                             bool isSigned, const SDLoc &dl) {
1992   TargetLowering::ArgListTy Args;
1993   Args.reserve(NumOps);
1994 
1995   TargetLowering::ArgListEntry Entry;
1996   for (unsigned i = 0; i != NumOps; ++i) {
1997     Entry.Node = Ops[i];
1998     Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
1999     Entry.isSExt = isSigned;
2000     Entry.isZExt = !isSigned;
2001     Args.push_back(Entry);
2002   }
2003   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2004                                          TLI.getPointerTy(DAG.getDataLayout()));
2005 
2006   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2007 
2008   TargetLowering::CallLoweringInfo CLI(DAG);
2009   CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
2010     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args))
2011     .setSExtResult(isSigned).setZExtResult(!isSigned);
2012 
2013   std::pair<SDValue,SDValue> CallInfo = TLI.LowerCallTo(CLI);
2014 
2015   return CallInfo.first;
2016 }
2017 
2018 // Expand a node into a call to a libcall. Similar to
2019 // ExpandLibCall except that the first operand is the in-chain.
2020 std::pair<SDValue, SDValue>
ExpandChainLibCall(RTLIB::Libcall LC,SDNode * Node,bool isSigned)2021 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
2022                                          SDNode *Node,
2023                                          bool isSigned) {
2024   SDValue InChain = Node->getOperand(0);
2025 
2026   TargetLowering::ArgListTy Args;
2027   TargetLowering::ArgListEntry Entry;
2028   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
2029     EVT ArgVT = Node->getOperand(i).getValueType();
2030     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2031     Entry.Node = Node->getOperand(i);
2032     Entry.Ty = ArgTy;
2033     Entry.isSExt = isSigned;
2034     Entry.isZExt = !isSigned;
2035     Args.push_back(Entry);
2036   }
2037   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2038                                          TLI.getPointerTy(DAG.getDataLayout()));
2039 
2040   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
2041 
2042   TargetLowering::CallLoweringInfo CLI(DAG);
2043   CLI.setDebugLoc(SDLoc(Node)).setChain(InChain)
2044     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args))
2045     .setSExtResult(isSigned).setZExtResult(!isSigned);
2046 
2047   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2048 
2049   return CallInfo;
2050 }
2051 
ExpandFPLibCall(SDNode * Node,RTLIB::Libcall Call_F32,RTLIB::Libcall Call_F64,RTLIB::Libcall Call_F80,RTLIB::Libcall Call_F128,RTLIB::Libcall Call_PPCF128)2052 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2053                                               RTLIB::Libcall Call_F32,
2054                                               RTLIB::Libcall Call_F64,
2055                                               RTLIB::Libcall Call_F80,
2056                                               RTLIB::Libcall Call_F128,
2057                                               RTLIB::Libcall Call_PPCF128) {
2058   RTLIB::Libcall LC;
2059   switch (Node->getSimpleValueType(0).SimpleTy) {
2060   default: llvm_unreachable("Unexpected request for libcall!");
2061   case MVT::f32: LC = Call_F32; break;
2062   case MVT::f64: LC = Call_F64; break;
2063   case MVT::f80: LC = Call_F80; break;
2064   case MVT::f128: LC = Call_F128; break;
2065   case MVT::ppcf128: LC = Call_PPCF128; break;
2066   }
2067   return ExpandLibCall(LC, Node, false);
2068 }
2069 
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)2070 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2071                                                RTLIB::Libcall Call_I8,
2072                                                RTLIB::Libcall Call_I16,
2073                                                RTLIB::Libcall Call_I32,
2074                                                RTLIB::Libcall Call_I64,
2075                                                RTLIB::Libcall Call_I128) {
2076   RTLIB::Libcall LC;
2077   switch (Node->getSimpleValueType(0).SimpleTy) {
2078   default: llvm_unreachable("Unexpected request for libcall!");
2079   case MVT::i8:   LC = Call_I8; break;
2080   case MVT::i16:  LC = Call_I16; break;
2081   case MVT::i32:  LC = Call_I32; break;
2082   case MVT::i64:  LC = Call_I64; break;
2083   case MVT::i128: LC = Call_I128; break;
2084   }
2085   return ExpandLibCall(LC, Node, isSigned);
2086 }
2087 
2088 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2089 void
ExpandDivRemLibCall(SDNode * Node,SmallVectorImpl<SDValue> & Results)2090 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2091                                           SmallVectorImpl<SDValue> &Results) {
2092   unsigned Opcode = Node->getOpcode();
2093   bool isSigned = Opcode == ISD::SDIVREM;
2094 
2095   RTLIB::Libcall LC;
2096   switch (Node->getSimpleValueType(0).SimpleTy) {
2097   default: llvm_unreachable("Unexpected request for libcall!");
2098   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2099   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2100   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2101   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2102   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2103   }
2104 
2105   // The input chain to this libcall is the entry node of the function.
2106   // Legalizing the call will automatically add the previous call to the
2107   // dependence.
2108   SDValue InChain = DAG.getEntryNode();
2109 
2110   EVT RetVT = Node->getValueType(0);
2111   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2112 
2113   TargetLowering::ArgListTy Args;
2114   TargetLowering::ArgListEntry Entry;
2115   for (const SDValue &Op : Node->op_values()) {
2116     EVT ArgVT = Op.getValueType();
2117     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2118     Entry.Node = Op;
2119     Entry.Ty = ArgTy;
2120     Entry.isSExt = isSigned;
2121     Entry.isZExt = !isSigned;
2122     Args.push_back(Entry);
2123   }
2124 
2125   // Also pass the return address of the remainder.
2126   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2127   Entry.Node = FIPtr;
2128   Entry.Ty = RetTy->getPointerTo();
2129   Entry.isSExt = isSigned;
2130   Entry.isZExt = !isSigned;
2131   Args.push_back(Entry);
2132 
2133   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2134                                          TLI.getPointerTy(DAG.getDataLayout()));
2135 
2136   SDLoc dl(Node);
2137   TargetLowering::CallLoweringInfo CLI(DAG);
2138   CLI.setDebugLoc(dl).setChain(InChain)
2139     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args))
2140     .setSExtResult(isSigned).setZExtResult(!isSigned);
2141 
2142   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2143 
2144   // Remainder is loaded back from the stack frame.
2145   SDValue Rem = DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr,
2146                             MachinePointerInfo(), false, false, false, 0);
2147   Results.push_back(CallInfo.first);
2148   Results.push_back(Rem);
2149 }
2150 
2151 /// Return true if sincos libcall is available.
isSinCosLibcallAvailable(SDNode * Node,const TargetLowering & TLI)2152 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2153   RTLIB::Libcall LC;
2154   switch (Node->getSimpleValueType(0).SimpleTy) {
2155   default: llvm_unreachable("Unexpected request for libcall!");
2156   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2157   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2158   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2159   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2160   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2161   }
2162   return TLI.getLibcallName(LC) != nullptr;
2163 }
2164 
2165 /// Return true if sincos libcall is available and can be used to combine sin
2166 /// and cos.
canCombineSinCosLibcall(SDNode * Node,const TargetLowering & TLI,const TargetMachine & TM)2167 static bool canCombineSinCosLibcall(SDNode *Node, const TargetLowering &TLI,
2168                                     const TargetMachine &TM) {
2169   if (!isSinCosLibcallAvailable(Node, TLI))
2170     return false;
2171   // GNU sin/cos functions set errno while sincos does not. Therefore
2172   // combining sin and cos is only safe if unsafe-fpmath is enabled.
2173   if (TM.getTargetTriple().isGNUEnvironment() && !TM.Options.UnsafeFPMath)
2174     return false;
2175   return true;
2176 }
2177 
2178 /// Only issue sincos libcall if both sin and cos are needed.
useSinCos(SDNode * Node)2179 static bool useSinCos(SDNode *Node) {
2180   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2181     ? ISD::FCOS : ISD::FSIN;
2182 
2183   SDValue Op0 = Node->getOperand(0);
2184   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2185        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2186     SDNode *User = *UI;
2187     if (User == Node)
2188       continue;
2189     // The other user might have been turned into sincos already.
2190     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2191       return true;
2192   }
2193   return false;
2194 }
2195 
2196 /// Issue libcalls to sincos to compute sin / cos pairs.
2197 void
ExpandSinCosLibCall(SDNode * Node,SmallVectorImpl<SDValue> & Results)2198 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2199                                           SmallVectorImpl<SDValue> &Results) {
2200   RTLIB::Libcall LC;
2201   switch (Node->getSimpleValueType(0).SimpleTy) {
2202   default: llvm_unreachable("Unexpected request for libcall!");
2203   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2204   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2205   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2206   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2207   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2208   }
2209 
2210   // The input chain to this libcall is the entry node of the function.
2211   // Legalizing the call will automatically add the previous call to the
2212   // dependence.
2213   SDValue InChain = DAG.getEntryNode();
2214 
2215   EVT RetVT = Node->getValueType(0);
2216   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2217 
2218   TargetLowering::ArgListTy Args;
2219   TargetLowering::ArgListEntry Entry;
2220 
2221   // Pass the argument.
2222   Entry.Node = Node->getOperand(0);
2223   Entry.Ty = RetTy;
2224   Entry.isSExt = false;
2225   Entry.isZExt = false;
2226   Args.push_back(Entry);
2227 
2228   // Pass the return address of sin.
2229   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2230   Entry.Node = SinPtr;
2231   Entry.Ty = RetTy->getPointerTo();
2232   Entry.isSExt = false;
2233   Entry.isZExt = false;
2234   Args.push_back(Entry);
2235 
2236   // Also pass the return address of the cos.
2237   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2238   Entry.Node = CosPtr;
2239   Entry.Ty = RetTy->getPointerTo();
2240   Entry.isSExt = false;
2241   Entry.isZExt = false;
2242   Args.push_back(Entry);
2243 
2244   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2245                                          TLI.getPointerTy(DAG.getDataLayout()));
2246 
2247   SDLoc dl(Node);
2248   TargetLowering::CallLoweringInfo CLI(DAG);
2249   CLI.setDebugLoc(dl).setChain(InChain)
2250     .setCallee(TLI.getLibcallCallingConv(LC),
2251                Type::getVoidTy(*DAG.getContext()), Callee, std::move(Args));
2252 
2253   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2254 
2255   Results.push_back(DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr,
2256                                 MachinePointerInfo(), false, false, false, 0));
2257   Results.push_back(DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr,
2258                                 MachinePointerInfo(), false, false, false, 0));
2259 }
2260 
2261 /// This function is responsible for legalizing a
2262 /// INT_TO_FP operation of the specified operand when the target requests that
2263 /// we expand it.  At this point, we know that the result and operand types are
2264 /// legal for the target.
ExpandLegalINT_TO_FP(bool isSigned,SDValue Op0,EVT DestVT,const SDLoc & dl)2265 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned, SDValue Op0,
2266                                                    EVT DestVT,
2267                                                    const SDLoc &dl) {
2268   // TODO: Should any fast-math-flags be set for the created nodes?
2269 
2270   if (Op0.getValueType() == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2271     // simple 32-bit [signed|unsigned] integer to float/double expansion
2272 
2273     // Get the stack frame index of a 8 byte buffer.
2274     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2275 
2276     // word offset constant for Hi/Lo address computation
2277     SDValue WordOff = DAG.getConstant(sizeof(int), dl,
2278                                       StackSlot.getValueType());
2279     // set up Hi and Lo (into buffer) address based on endian
2280     SDValue Hi = StackSlot;
2281     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
2282                              StackSlot, WordOff);
2283     if (DAG.getDataLayout().isLittleEndian())
2284       std::swap(Hi, Lo);
2285 
2286     // if signed map to unsigned space
2287     SDValue Op0Mapped;
2288     if (isSigned) {
2289       // constant used to invert sign bit (signed to unsigned mapping)
2290       SDValue SignBit = DAG.getConstant(0x80000000u, dl, MVT::i32);
2291       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
2292     } else {
2293       Op0Mapped = Op0;
2294     }
2295     // store the lo of the constructed double - based on integer input
2296     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl,
2297                                   Op0Mapped, Lo, MachinePointerInfo(),
2298                                   false, false, 0);
2299     // initial hi portion of constructed double
2300     SDValue InitialHi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2301     // store the hi of the constructed double - biased exponent
2302     SDValue Store2 = DAG.getStore(Store1, dl, InitialHi, Hi,
2303                                   MachinePointerInfo(),
2304                                   false, false, 0);
2305     // load the constructed double
2306     SDValue Load = DAG.getLoad(MVT::f64, dl, Store2, StackSlot,
2307                                MachinePointerInfo(), false, false, false, 0);
2308     // FP constant to bias correct the final result
2309     SDValue Bias = DAG.getConstantFP(isSigned ?
2310                                      BitsToDouble(0x4330000080000000ULL) :
2311                                      BitsToDouble(0x4330000000000000ULL),
2312                                      dl, MVT::f64);
2313     // subtract the bias
2314     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2315     // final result
2316     SDValue Result;
2317     // handle final rounding
2318     if (DestVT == MVT::f64) {
2319       // do nothing
2320       Result = Sub;
2321     } else if (DestVT.bitsLT(MVT::f64)) {
2322       Result = DAG.getNode(ISD::FP_ROUND, dl, DestVT, Sub,
2323                            DAG.getIntPtrConstant(0, dl));
2324     } else if (DestVT.bitsGT(MVT::f64)) {
2325       Result = DAG.getNode(ISD::FP_EXTEND, dl, DestVT, Sub);
2326     }
2327     return Result;
2328   }
2329   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2330   // Code below here assumes !isSigned without checking again.
2331 
2332   // Implementation of unsigned i64 to f64 following the algorithm in
2333   // __floatundidf in compiler_rt. This implementation has the advantage
2334   // of performing rounding correctly, both in the default rounding mode
2335   // and in all alternate rounding modes.
2336   // TODO: Generalize this for use with other types.
2337   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f64) {
2338     SDValue TwoP52 =
2339       DAG.getConstant(UINT64_C(0x4330000000000000), dl, MVT::i64);
2340     SDValue TwoP84PlusTwoP52 =
2341       DAG.getConstantFP(BitsToDouble(UINT64_C(0x4530000000100000)), dl,
2342                         MVT::f64);
2343     SDValue TwoP84 =
2344       DAG.getConstant(UINT64_C(0x4530000000000000), dl, MVT::i64);
2345 
2346     SDValue Lo = DAG.getZeroExtendInReg(Op0, dl, MVT::i32);
2347     SDValue Hi = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0,
2348                              DAG.getConstant(32, dl, MVT::i64));
2349     SDValue LoOr = DAG.getNode(ISD::OR, dl, MVT::i64, Lo, TwoP52);
2350     SDValue HiOr = DAG.getNode(ISD::OR, dl, MVT::i64, Hi, TwoP84);
2351     SDValue LoFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, LoOr);
2352     SDValue HiFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, HiOr);
2353     SDValue HiSub = DAG.getNode(ISD::FSUB, dl, MVT::f64, HiFlt,
2354                                 TwoP84PlusTwoP52);
2355     return DAG.getNode(ISD::FADD, dl, MVT::f64, LoFlt, HiSub);
2356   }
2357 
2358   // Implementation of unsigned i64 to f32.
2359   // TODO: Generalize this for use with other types.
2360   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f32) {
2361     // For unsigned conversions, convert them to signed conversions using the
2362     // algorithm from the x86_64 __floatundidf in compiler_rt.
2363     if (!isSigned) {
2364       SDValue Fast = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Op0);
2365 
2366       SDValue ShiftConst = DAG.getConstant(
2367           1, dl, TLI.getShiftAmountTy(Op0.getValueType(), DAG.getDataLayout()));
2368       SDValue Shr = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0, ShiftConst);
2369       SDValue AndConst = DAG.getConstant(1, dl, MVT::i64);
2370       SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0, AndConst);
2371       SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And, Shr);
2372 
2373       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Or);
2374       SDValue Slow = DAG.getNode(ISD::FADD, dl, MVT::f32, SignCvt, SignCvt);
2375 
2376       // TODO: This really should be implemented using a branch rather than a
2377       // select.  We happen to get lucky and machinesink does the right
2378       // thing most of the time.  This would be a good candidate for a
2379       //pseudo-op, or, even better, for whole-function isel.
2380       SDValue SignBitTest = DAG.getSetCC(dl, getSetCCResultType(MVT::i64),
2381         Op0, DAG.getConstant(0, dl, MVT::i64), ISD::SETLT);
2382       return DAG.getSelect(dl, MVT::f32, SignBitTest, Slow, Fast);
2383     }
2384 
2385     // Otherwise, implement the fully general conversion.
2386 
2387     SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
2388          DAG.getConstant(UINT64_C(0xfffffffffffff800), dl, MVT::i64));
2389     SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And,
2390          DAG.getConstant(UINT64_C(0x800), dl, MVT::i64));
2391     SDValue And2 = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
2392          DAG.getConstant(UINT64_C(0x7ff), dl, MVT::i64));
2393     SDValue Ne = DAG.getSetCC(dl, getSetCCResultType(MVT::i64), And2,
2394                               DAG.getConstant(UINT64_C(0), dl, MVT::i64),
2395                               ISD::SETNE);
2396     SDValue Sel = DAG.getSelect(dl, MVT::i64, Ne, Or, Op0);
2397     SDValue Ge = DAG.getSetCC(dl, getSetCCResultType(MVT::i64), Op0,
2398                               DAG.getConstant(UINT64_C(0x0020000000000000), dl,
2399                                               MVT::i64),
2400                               ISD::SETUGE);
2401     SDValue Sel2 = DAG.getSelect(dl, MVT::i64, Ge, Sel, Op0);
2402     EVT SHVT = TLI.getShiftAmountTy(Sel2.getValueType(), DAG.getDataLayout());
2403 
2404     SDValue Sh = DAG.getNode(ISD::SRL, dl, MVT::i64, Sel2,
2405                              DAG.getConstant(32, dl, SHVT));
2406     SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sh);
2407     SDValue Fcvt = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Trunc);
2408     SDValue TwoP32 =
2409       DAG.getConstantFP(BitsToDouble(UINT64_C(0x41f0000000000000)), dl,
2410                         MVT::f64);
2411     SDValue Fmul = DAG.getNode(ISD::FMUL, dl, MVT::f64, TwoP32, Fcvt);
2412     SDValue Lo = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sel2);
2413     SDValue Fcvt2 = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Lo);
2414     SDValue Fadd = DAG.getNode(ISD::FADD, dl, MVT::f64, Fmul, Fcvt2);
2415     return DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Fadd,
2416                        DAG.getIntPtrConstant(0, dl));
2417   }
2418 
2419   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2420 
2421   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(Op0.getValueType()),
2422                                  Op0,
2423                                  DAG.getConstant(0, dl, Op0.getValueType()),
2424                                  ISD::SETLT);
2425   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2426           Four = DAG.getIntPtrConstant(4, dl);
2427   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2428                                     SignSet, Four, Zero);
2429 
2430   // If the sign bit of the integer is set, the large number will be treated
2431   // as a negative number.  To counteract this, the dynamic code adds an
2432   // offset depending on the data type.
2433   uint64_t FF;
2434   switch (Op0.getSimpleValueType().SimpleTy) {
2435   default: llvm_unreachable("Unsupported integer type!");
2436   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2437   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2438   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2439   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2440   }
2441   if (DAG.getDataLayout().isLittleEndian())
2442     FF <<= 32;
2443   Constant *FudgeFactor = ConstantInt::get(
2444                                        Type::getInt64Ty(*DAG.getContext()), FF);
2445 
2446   SDValue CPIdx =
2447       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2448   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
2449   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2450   Alignment = std::min(Alignment, 4u);
2451   SDValue FudgeInReg;
2452   if (DestVT == MVT::f32)
2453     FudgeInReg = DAG.getLoad(
2454         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2455         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), false,
2456         false, false, Alignment);
2457   else {
2458     SDValue Load = DAG.getExtLoad(
2459         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2460         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2461         false, false, false, Alignment);
2462     HandleSDNode Handle(Load);
2463     LegalizeOp(Load.getNode());
2464     FudgeInReg = Handle.getValue();
2465   }
2466 
2467   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2468 }
2469 
2470 /// This function is responsible for legalizing a
2471 /// *INT_TO_FP operation of the specified operand when the target requests that
2472 /// we promote it.  At this point, we know that the result and operand types are
2473 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2474 /// operation that takes a larger input.
PromoteLegalINT_TO_FP(SDValue LegalOp,EVT DestVT,bool isSigned,const SDLoc & dl)2475 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT,
2476                                                     bool isSigned,
2477                                                     const SDLoc &dl) {
2478   // First step, figure out the appropriate *INT_TO_FP operation to use.
2479   EVT NewInTy = LegalOp.getValueType();
2480 
2481   unsigned OpToUse = 0;
2482 
2483   // Scan for the appropriate larger type to use.
2484   while (1) {
2485     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2486     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2487 
2488     // If the target supports SINT_TO_FP of this type, use it.
2489     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
2490       OpToUse = ISD::SINT_TO_FP;
2491       break;
2492     }
2493     if (isSigned) continue;
2494 
2495     // If the target supports UINT_TO_FP of this type, use it.
2496     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
2497       OpToUse = ISD::UINT_TO_FP;
2498       break;
2499     }
2500 
2501     // Otherwise, try a larger type.
2502   }
2503 
2504   // Okay, we found the operation and type to use.  Zero extend our input to the
2505   // desired type then run the operation on it.
2506   return DAG.getNode(OpToUse, dl, DestVT,
2507                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2508                                  dl, NewInTy, LegalOp));
2509 }
2510 
2511 /// This function is responsible for legalizing a
2512 /// FP_TO_*INT operation of the specified operand when the target requests that
2513 /// we promote it.  At this point, we know that the result and operand types are
2514 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2515 /// operation that returns a larger result.
PromoteLegalFP_TO_INT(SDValue LegalOp,EVT DestVT,bool isSigned,const SDLoc & dl)2516 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT,
2517                                                     bool isSigned,
2518                                                     const SDLoc &dl) {
2519   // First step, figure out the appropriate FP_TO*INT operation to use.
2520   EVT NewOutTy = DestVT;
2521 
2522   unsigned OpToUse = 0;
2523 
2524   // Scan for the appropriate larger type to use.
2525   while (1) {
2526     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2527     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2528 
2529     // A larger signed type can hold all unsigned values of the requested type,
2530     // so using FP_TO_SINT is valid
2531     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
2532       OpToUse = ISD::FP_TO_SINT;
2533       break;
2534     }
2535 
2536     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2537     if (!isSigned && TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
2538       OpToUse = ISD::FP_TO_UINT;
2539       break;
2540     }
2541 
2542     // Otherwise, try a larger type.
2543   }
2544 
2545 
2546   // Okay, we found the operation and type to use.
2547   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2548 
2549   // Truncate the result of the extended FP_TO_*INT operation to the desired
2550   // size.
2551   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2552 }
2553 
2554 /// Open code the operations for BITREVERSE.
ExpandBITREVERSE(SDValue Op,const SDLoc & dl)2555 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2556   EVT VT = Op.getValueType();
2557   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2558   unsigned Sz = VT.getScalarSizeInBits();
2559 
2560   SDValue Tmp, Tmp2;
2561   Tmp = DAG.getConstant(0, dl, VT);
2562   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2563     if (I < J)
2564       Tmp2 =
2565           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2566     else
2567       Tmp2 =
2568           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2569 
2570     APInt Shift(Sz, 1);
2571     Shift = Shift.shl(J);
2572     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2573     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2574   }
2575 
2576   return Tmp;
2577 }
2578 
2579 /// Open code the operations for BSWAP of the specified operation.
ExpandBSWAP(SDValue Op,const SDLoc & dl)2580 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2581   EVT VT = Op.getValueType();
2582   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2583   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2584   switch (VT.getSimpleVT().SimpleTy) {
2585   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2586   case MVT::i16:
2587     Tmp2 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2588     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2589     return DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
2590   case MVT::i32:
2591     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2592     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2593     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2594     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2595     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2596                        DAG.getConstant(0xFF0000, dl, VT));
2597     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2598     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2599     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2600     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2601   case MVT::i64:
2602     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2603     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2604     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2605     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2606     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2607     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2608     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2609     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2610     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2611                        DAG.getConstant(255ULL<<48, dl, VT));
2612     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2613                        DAG.getConstant(255ULL<<40, dl, VT));
2614     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2615                        DAG.getConstant(255ULL<<32, dl, VT));
2616     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2617                        DAG.getConstant(255ULL<<24, dl, VT));
2618     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2619                        DAG.getConstant(255ULL<<16, dl, VT));
2620     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2621                        DAG.getConstant(255ULL<<8 , dl, VT));
2622     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2623     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2624     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2625     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2626     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2627     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2628     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2629   }
2630 }
2631 
2632 /// Expand the specified bitcount instruction into operations.
ExpandBitCount(unsigned Opc,SDValue Op,const SDLoc & dl)2633 SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
2634                                              const SDLoc &dl) {
2635   switch (Opc) {
2636   default: llvm_unreachable("Cannot expand this yet!");
2637   case ISD::CTPOP: {
2638     EVT VT = Op.getValueType();
2639     EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2640     unsigned Len = VT.getSizeInBits();
2641 
2642     assert(VT.isInteger() && Len <= 128 && Len % 8 == 0 &&
2643            "CTPOP not implemented for this type.");
2644 
2645     // This is the "best" algorithm from
2646     // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
2647 
2648     SDValue Mask55 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x55)),
2649                                      dl, VT);
2650     SDValue Mask33 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x33)),
2651                                      dl, VT);
2652     SDValue Mask0F = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x0F)),
2653                                      dl, VT);
2654     SDValue Mask01 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x01)),
2655                                      dl, VT);
2656 
2657     // v = v - ((v >> 1) & 0x55555555...)
2658     Op = DAG.getNode(ISD::SUB, dl, VT, Op,
2659                      DAG.getNode(ISD::AND, dl, VT,
2660                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2661                                              DAG.getConstant(1, dl, ShVT)),
2662                                  Mask55));
2663     // v = (v & 0x33333333...) + ((v >> 2) & 0x33333333...)
2664     Op = DAG.getNode(ISD::ADD, dl, VT,
2665                      DAG.getNode(ISD::AND, dl, VT, Op, Mask33),
2666                      DAG.getNode(ISD::AND, dl, VT,
2667                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2668                                              DAG.getConstant(2, dl, ShVT)),
2669                                  Mask33));
2670     // v = (v + (v >> 4)) & 0x0F0F0F0F...
2671     Op = DAG.getNode(ISD::AND, dl, VT,
2672                      DAG.getNode(ISD::ADD, dl, VT, Op,
2673                                  DAG.getNode(ISD::SRL, dl, VT, Op,
2674                                              DAG.getConstant(4, dl, ShVT))),
2675                      Mask0F);
2676     // v = (v * 0x01010101...) >> (Len - 8)
2677     Op = DAG.getNode(ISD::SRL, dl, VT,
2678                      DAG.getNode(ISD::MUL, dl, VT, Op, Mask01),
2679                      DAG.getConstant(Len - 8, dl, ShVT));
2680 
2681     return Op;
2682   }
2683   case ISD::CTLZ_ZERO_UNDEF:
2684     // This trivially expands to CTLZ.
2685     return DAG.getNode(ISD::CTLZ, dl, Op.getValueType(), Op);
2686   case ISD::CTLZ: {
2687     EVT VT = Op.getValueType();
2688     unsigned len = VT.getSizeInBits();
2689 
2690     if (TLI.isOperationLegalOrCustom(ISD::CTLZ_ZERO_UNDEF, VT)) {
2691       EVT SetCCVT = getSetCCResultType(VT);
2692       SDValue CTLZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, dl, VT, Op);
2693       SDValue Zero = DAG.getConstant(0, dl, VT);
2694       SDValue SrcIsZero = DAG.getSetCC(dl, SetCCVT, Op, Zero, ISD::SETEQ);
2695       return DAG.getNode(ISD::SELECT, dl, VT, SrcIsZero,
2696                          DAG.getConstant(len, dl, VT), CTLZ);
2697     }
2698 
2699     // for now, we do this:
2700     // x = x | (x >> 1);
2701     // x = x | (x >> 2);
2702     // ...
2703     // x = x | (x >>16);
2704     // x = x | (x >>32); // for 64-bit input
2705     // return popcount(~x);
2706     //
2707     // Ref: "Hacker's Delight" by Henry Warren
2708     EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2709     for (unsigned i = 0; (1U << i) <= (len / 2); ++i) {
2710       SDValue Tmp3 = DAG.getConstant(1ULL << i, dl, ShVT);
2711       Op = DAG.getNode(ISD::OR, dl, VT, Op,
2712                        DAG.getNode(ISD::SRL, dl, VT, Op, Tmp3));
2713     }
2714     Op = DAG.getNOT(dl, Op, VT);
2715     return DAG.getNode(ISD::CTPOP, dl, VT, Op);
2716   }
2717   case ISD::CTTZ_ZERO_UNDEF:
2718     // This trivially expands to CTTZ.
2719     return DAG.getNode(ISD::CTTZ, dl, Op.getValueType(), Op);
2720   case ISD::CTTZ: {
2721     // for now, we use: { return popcount(~x & (x - 1)); }
2722     // unless the target has ctlz but not ctpop, in which case we use:
2723     // { return 32 - nlz(~x & (x-1)); }
2724     // Ref: "Hacker's Delight" by Henry Warren
2725     EVT VT = Op.getValueType();
2726     SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT,
2727                                DAG.getNOT(dl, Op, VT),
2728                                DAG.getNode(ISD::SUB, dl, VT, Op,
2729                                            DAG.getConstant(1, dl, VT)));
2730     // If ISD::CTLZ is legal and CTPOP isn't, then do that instead.
2731     if (!TLI.isOperationLegalOrCustom(ISD::CTPOP, VT) &&
2732         TLI.isOperationLegalOrCustom(ISD::CTLZ, VT))
2733       return DAG.getNode(ISD::SUB, dl, VT,
2734                          DAG.getConstant(VT.getSizeInBits(), dl, VT),
2735                          DAG.getNode(ISD::CTLZ, dl, VT, Tmp3));
2736     return DAG.getNode(ISD::CTPOP, dl, VT, Tmp3);
2737   }
2738   }
2739 }
2740 
ExpandNode(SDNode * Node)2741 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2742   SmallVector<SDValue, 8> Results;
2743   SDLoc dl(Node);
2744   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2745   bool NeedInvert;
2746   switch (Node->getOpcode()) {
2747   case ISD::CTPOP:
2748   case ISD::CTLZ:
2749   case ISD::CTLZ_ZERO_UNDEF:
2750   case ISD::CTTZ:
2751   case ISD::CTTZ_ZERO_UNDEF:
2752     Tmp1 = ExpandBitCount(Node->getOpcode(), Node->getOperand(0), dl);
2753     Results.push_back(Tmp1);
2754     break;
2755   case ISD::BITREVERSE:
2756     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2757     break;
2758   case ISD::BSWAP:
2759     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2760     break;
2761   case ISD::FRAMEADDR:
2762   case ISD::RETURNADDR:
2763   case ISD::FRAME_TO_ARGS_OFFSET:
2764     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2765     break;
2766   case ISD::FLT_ROUNDS_:
2767     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2768     break;
2769   case ISD::EH_RETURN:
2770   case ISD::EH_LABEL:
2771   case ISD::PREFETCH:
2772   case ISD::VAEND:
2773   case ISD::EH_SJLJ_LONGJMP:
2774     // If the target didn't expand these, there's nothing to do, so just
2775     // preserve the chain and be done.
2776     Results.push_back(Node->getOperand(0));
2777     break;
2778   case ISD::READCYCLECOUNTER:
2779     // If the target didn't expand this, just return 'zero' and preserve the
2780     // chain.
2781     Results.append(Node->getNumValues() - 1,
2782                    DAG.getConstant(0, dl, Node->getValueType(0)));
2783     Results.push_back(Node->getOperand(0));
2784     break;
2785   case ISD::EH_SJLJ_SETJMP:
2786     // If the target didn't expand this, just return 'zero' and preserve the
2787     // chain.
2788     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2789     Results.push_back(Node->getOperand(0));
2790     break;
2791   case ISD::ATOMIC_LOAD: {
2792     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2793     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2794     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2795     SDValue Swap = DAG.getAtomicCmpSwap(
2796         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2797         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2798         cast<AtomicSDNode>(Node)->getMemOperand(),
2799         cast<AtomicSDNode>(Node)->getOrdering(),
2800         cast<AtomicSDNode>(Node)->getOrdering(),
2801         cast<AtomicSDNode>(Node)->getSynchScope());
2802     Results.push_back(Swap.getValue(0));
2803     Results.push_back(Swap.getValue(1));
2804     break;
2805   }
2806   case ISD::ATOMIC_STORE: {
2807     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2808     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2809                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2810                                  Node->getOperand(0),
2811                                  Node->getOperand(1), Node->getOperand(2),
2812                                  cast<AtomicSDNode>(Node)->getMemOperand(),
2813                                  cast<AtomicSDNode>(Node)->getOrdering(),
2814                                  cast<AtomicSDNode>(Node)->getSynchScope());
2815     Results.push_back(Swap.getValue(1));
2816     break;
2817   }
2818   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2819     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2820     // splits out the success value as a comparison. Expanding the resulting
2821     // ATOMIC_CMP_SWAP will produce a libcall.
2822     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2823     SDValue Res = DAG.getAtomicCmpSwap(
2824         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2825         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2826         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand(),
2827         cast<AtomicSDNode>(Node)->getSuccessOrdering(),
2828         cast<AtomicSDNode>(Node)->getFailureOrdering(),
2829         cast<AtomicSDNode>(Node)->getSynchScope());
2830 
2831     SDValue ExtRes = Res;
2832     SDValue LHS = Res;
2833     SDValue RHS = Node->getOperand(1);
2834 
2835     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2836     EVT OuterType = Node->getValueType(0);
2837     switch (TLI.getExtendForAtomicOps()) {
2838     case ISD::SIGN_EXTEND:
2839       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2840                         DAG.getValueType(AtomicType));
2841       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2842                         Node->getOperand(2), DAG.getValueType(AtomicType));
2843       ExtRes = LHS;
2844       break;
2845     case ISD::ZERO_EXTEND:
2846       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2847                         DAG.getValueType(AtomicType));
2848       RHS = DAG.getNode(ISD::ZERO_EXTEND, dl, OuterType, Node->getOperand(2));
2849       ExtRes = LHS;
2850       break;
2851     case ISD::ANY_EXTEND:
2852       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2853       RHS = DAG.getNode(ISD::ZERO_EXTEND, dl, OuterType, Node->getOperand(2));
2854       break;
2855     default:
2856       llvm_unreachable("Invalid atomic op extension");
2857     }
2858 
2859     SDValue Success =
2860         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2861 
2862     Results.push_back(ExtRes.getValue(0));
2863     Results.push_back(Success);
2864     Results.push_back(Res.getValue(1));
2865     break;
2866   }
2867   case ISD::DYNAMIC_STACKALLOC:
2868     ExpandDYNAMIC_STACKALLOC(Node, Results);
2869     break;
2870   case ISD::MERGE_VALUES:
2871     for (unsigned i = 0; i < Node->getNumValues(); i++)
2872       Results.push_back(Node->getOperand(i));
2873     break;
2874   case ISD::UNDEF: {
2875     EVT VT = Node->getValueType(0);
2876     if (VT.isInteger())
2877       Results.push_back(DAG.getConstant(0, dl, VT));
2878     else {
2879       assert(VT.isFloatingPoint() && "Unknown value type!");
2880       Results.push_back(DAG.getConstantFP(0, dl, VT));
2881     }
2882     break;
2883   }
2884   case ISD::FP_ROUND:
2885   case ISD::BITCAST:
2886     Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
2887                             Node->getValueType(0), dl);
2888     Results.push_back(Tmp1);
2889     break;
2890   case ISD::FP_EXTEND:
2891     Tmp1 = EmitStackConvert(Node->getOperand(0),
2892                             Node->getOperand(0).getValueType(),
2893                             Node->getValueType(0), dl);
2894     Results.push_back(Tmp1);
2895     break;
2896   case ISD::SIGN_EXTEND_INREG: {
2897     // NOTE: we could fall back on load/store here too for targets without
2898     // SAR.  However, it is doubtful that any exist.
2899     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2900     EVT VT = Node->getValueType(0);
2901     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2902     if (VT.isVector())
2903       ShiftAmountTy = VT;
2904     unsigned BitsDiff = VT.getScalarType().getSizeInBits() -
2905                         ExtraVT.getScalarType().getSizeInBits();
2906     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
2907     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
2908                        Node->getOperand(0), ShiftCst);
2909     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
2910     Results.push_back(Tmp1);
2911     break;
2912   }
2913   case ISD::FP_ROUND_INREG: {
2914     // The only way we can lower this is to turn it into a TRUNCSTORE,
2915     // EXTLOAD pair, targeting a temporary location (a stack slot).
2916 
2917     // NOTE: there is a choice here between constantly creating new stack
2918     // slots and always reusing the same one.  We currently always create
2919     // new ones, as reuse may inhibit scheduling.
2920     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
2921     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
2922                             Node->getValueType(0), dl);
2923     Results.push_back(Tmp1);
2924     break;
2925   }
2926   case ISD::SINT_TO_FP:
2927   case ISD::UINT_TO_FP:
2928     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
2929                                 Node->getOperand(0), Node->getValueType(0), dl);
2930     Results.push_back(Tmp1);
2931     break;
2932   case ISD::FP_TO_SINT:
2933     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
2934       Results.push_back(Tmp1);
2935     break;
2936   case ISD::FP_TO_UINT: {
2937     SDValue True, False;
2938     EVT VT =  Node->getOperand(0).getValueType();
2939     EVT NVT = Node->getValueType(0);
2940     APFloat apf(DAG.EVTToAPFloatSemantics(VT),
2941                 APInt::getNullValue(VT.getSizeInBits()));
2942     APInt x = APInt::getSignBit(NVT.getSizeInBits());
2943     (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
2944     Tmp1 = DAG.getConstantFP(apf, dl, VT);
2945     Tmp2 = DAG.getSetCC(dl, getSetCCResultType(VT),
2946                         Node->getOperand(0),
2947                         Tmp1, ISD::SETLT);
2948     True = DAG.getNode(ISD::FP_TO_SINT, dl, NVT, Node->getOperand(0));
2949     // TODO: Should any fast-math-flags be set for the FSUB?
2950     False = DAG.getNode(ISD::FP_TO_SINT, dl, NVT,
2951                         DAG.getNode(ISD::FSUB, dl, VT,
2952                                     Node->getOperand(0), Tmp1));
2953     False = DAG.getNode(ISD::XOR, dl, NVT, False,
2954                         DAG.getConstant(x, dl, NVT));
2955     Tmp1 = DAG.getSelect(dl, NVT, Tmp2, True, False);
2956     Results.push_back(Tmp1);
2957     break;
2958   }
2959   case ISD::VAARG:
2960     Results.push_back(DAG.expandVAArg(Node));
2961     Results.push_back(Results[0].getValue(1));
2962     break;
2963   case ISD::VACOPY:
2964     Results.push_back(DAG.expandVACopy(Node));
2965     break;
2966   case ISD::EXTRACT_VECTOR_ELT:
2967     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
2968       // This must be an access of the only element.  Return it.
2969       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
2970                          Node->getOperand(0));
2971     else
2972       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
2973     Results.push_back(Tmp1);
2974     break;
2975   case ISD::EXTRACT_SUBVECTOR:
2976     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
2977     break;
2978   case ISD::INSERT_SUBVECTOR:
2979     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
2980     break;
2981   case ISD::CONCAT_VECTORS: {
2982     Results.push_back(ExpandVectorBuildThroughStack(Node));
2983     break;
2984   }
2985   case ISD::SCALAR_TO_VECTOR:
2986     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
2987     break;
2988   case ISD::INSERT_VECTOR_ELT:
2989     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
2990                                               Node->getOperand(1),
2991                                               Node->getOperand(2), dl));
2992     break;
2993   case ISD::VECTOR_SHUFFLE: {
2994     SmallVector<int, 32> NewMask;
2995     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
2996 
2997     EVT VT = Node->getValueType(0);
2998     EVT EltVT = VT.getVectorElementType();
2999     SDValue Op0 = Node->getOperand(0);
3000     SDValue Op1 = Node->getOperand(1);
3001     if (!TLI.isTypeLegal(EltVT)) {
3002 
3003       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3004 
3005       // BUILD_VECTOR operands are allowed to be wider than the element type.
3006       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3007       // it.
3008       if (NewEltVT.bitsLT(EltVT)) {
3009 
3010         // Convert shuffle node.
3011         // If original node was v4i64 and the new EltVT is i32,
3012         // cast operands to v8i32 and re-build the mask.
3013 
3014         // Calculate new VT, the size of the new VT should be equal to original.
3015         EVT NewVT =
3016             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3017                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3018         assert(NewVT.bitsEq(VT));
3019 
3020         // cast operands to new VT
3021         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3022         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3023 
3024         // Convert the shuffle mask
3025         unsigned int factor =
3026                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3027 
3028         // EltVT gets smaller
3029         assert(factor > 0);
3030 
3031         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3032           if (Mask[i] < 0) {
3033             for (unsigned fi = 0; fi < factor; ++fi)
3034               NewMask.push_back(Mask[i]);
3035           }
3036           else {
3037             for (unsigned fi = 0; fi < factor; ++fi)
3038               NewMask.push_back(Mask[i]*factor+fi);
3039           }
3040         }
3041         Mask = NewMask;
3042         VT = NewVT;
3043       }
3044       EltVT = NewEltVT;
3045     }
3046     unsigned NumElems = VT.getVectorNumElements();
3047     SmallVector<SDValue, 16> Ops;
3048     for (unsigned i = 0; i != NumElems; ++i) {
3049       if (Mask[i] < 0) {
3050         Ops.push_back(DAG.getUNDEF(EltVT));
3051         continue;
3052       }
3053       unsigned Idx = Mask[i];
3054       if (Idx < NumElems)
3055         Ops.push_back(DAG.getNode(
3056             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3057             DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout()))));
3058       else
3059         Ops.push_back(DAG.getNode(
3060             ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3061             DAG.getConstant(Idx - NumElems, dl,
3062                             TLI.getVectorIdxTy(DAG.getDataLayout()))));
3063     }
3064 
3065     Tmp1 = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
3066     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3067     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3068     Results.push_back(Tmp1);
3069     break;
3070   }
3071   case ISD::EXTRACT_ELEMENT: {
3072     EVT OpTy = Node->getOperand(0).getValueType();
3073     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3074       // 1 -> Hi
3075       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3076                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3077                                          TLI.getShiftAmountTy(
3078                                              Node->getOperand(0).getValueType(),
3079                                              DAG.getDataLayout())));
3080       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3081     } else {
3082       // 0 -> Lo
3083       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3084                          Node->getOperand(0));
3085     }
3086     Results.push_back(Tmp1);
3087     break;
3088   }
3089   case ISD::STACKSAVE:
3090     // Expand to CopyFromReg if the target set
3091     // StackPointerRegisterToSaveRestore.
3092     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3093       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3094                                            Node->getValueType(0)));
3095       Results.push_back(Results[0].getValue(1));
3096     } else {
3097       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3098       Results.push_back(Node->getOperand(0));
3099     }
3100     break;
3101   case ISD::STACKRESTORE:
3102     // Expand to CopyToReg if the target set
3103     // StackPointerRegisterToSaveRestore.
3104     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3105       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3106                                          Node->getOperand(1)));
3107     } else {
3108       Results.push_back(Node->getOperand(0));
3109     }
3110     break;
3111   case ISD::GET_DYNAMIC_AREA_OFFSET:
3112     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3113     Results.push_back(Results[0].getValue(0));
3114     break;
3115   case ISD::FCOPYSIGN:
3116     Results.push_back(ExpandFCOPYSIGN(Node));
3117     break;
3118   case ISD::FNEG:
3119     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
3120     Tmp1 = DAG.getConstantFP(-0.0, dl, Node->getValueType(0));
3121     // TODO: If FNEG has fast-math-flags, propagate them to the FSUB.
3122     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
3123                        Node->getOperand(0));
3124     Results.push_back(Tmp1);
3125     break;
3126   case ISD::FABS:
3127     Results.push_back(ExpandFABS(Node));
3128     break;
3129   case ISD::SMIN:
3130   case ISD::SMAX:
3131   case ISD::UMIN:
3132   case ISD::UMAX: {
3133     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3134     ISD::CondCode Pred;
3135     switch (Node->getOpcode()) {
3136     default: llvm_unreachable("How did we get here?");
3137     case ISD::SMAX: Pred = ISD::SETGT; break;
3138     case ISD::SMIN: Pred = ISD::SETLT; break;
3139     case ISD::UMAX: Pred = ISD::SETUGT; break;
3140     case ISD::UMIN: Pred = ISD::SETULT; break;
3141     }
3142     Tmp1 = Node->getOperand(0);
3143     Tmp2 = Node->getOperand(1);
3144     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3145     Results.push_back(Tmp1);
3146     break;
3147   }
3148 
3149   case ISD::FSIN:
3150   case ISD::FCOS: {
3151     EVT VT = Node->getValueType(0);
3152     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3153     // fcos which share the same operand and both are used.
3154     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3155          canCombineSinCosLibcall(Node, TLI, TM))
3156         && useSinCos(Node)) {
3157       SDVTList VTs = DAG.getVTList(VT, VT);
3158       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3159       if (Node->getOpcode() == ISD::FCOS)
3160         Tmp1 = Tmp1.getValue(1);
3161       Results.push_back(Tmp1);
3162     }
3163     break;
3164   }
3165   case ISD::FMAD:
3166     llvm_unreachable("Illegal fmad should never be formed");
3167 
3168   case ISD::FP16_TO_FP:
3169     if (Node->getValueType(0) != MVT::f32) {
3170       // We can extend to types bigger than f32 in two steps without changing
3171       // the result. Since "f16 -> f32" is much more commonly available, give
3172       // CodeGen the option of emitting that before resorting to a libcall.
3173       SDValue Res =
3174           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3175       Results.push_back(
3176           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3177     }
3178     break;
3179   case ISD::FP_TO_FP16:
3180     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3181       SDValue Op = Node->getOperand(0);
3182       MVT SVT = Op.getSimpleValueType();
3183       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3184           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3185         // Under fastmath, we can expand this node into a fround followed by
3186         // a float-half conversion.
3187         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3188                                        DAG.getIntPtrConstant(0, dl));
3189         Results.push_back(
3190             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3191       }
3192     }
3193     break;
3194   case ISD::ConstantFP: {
3195     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3196     // Check to see if this FP immediate is already legal.
3197     // If this is a legal constant, turn it into a TargetConstantFP node.
3198     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0)))
3199       Results.push_back(ExpandConstantFP(CFP, true));
3200     break;
3201   }
3202   case ISD::Constant: {
3203     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3204     Results.push_back(ExpandConstant(CP));
3205     break;
3206   }
3207   case ISD::FSUB: {
3208     EVT VT = Node->getValueType(0);
3209     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3210         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3211       const SDNodeFlags *Flags = &cast<BinaryWithFlagsSDNode>(Node)->Flags;
3212       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3213       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3214       Results.push_back(Tmp1);
3215     }
3216     break;
3217   }
3218   case ISD::SUB: {
3219     EVT VT = Node->getValueType(0);
3220     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3221            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3222            "Don't know how to expand this subtraction!");
3223     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3224                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3225                                VT));
3226     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3227     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3228     break;
3229   }
3230   case ISD::UREM:
3231   case ISD::SREM: {
3232     EVT VT = Node->getValueType(0);
3233     bool isSigned = Node->getOpcode() == ISD::SREM;
3234     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
3235     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3236     Tmp2 = Node->getOperand(0);
3237     Tmp3 = Node->getOperand(1);
3238     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3239       SDVTList VTs = DAG.getVTList(VT, VT);
3240       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
3241       Results.push_back(Tmp1);
3242     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
3243       // X % Y -> X-X/Y*Y
3244       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
3245       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
3246       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
3247       Results.push_back(Tmp1);
3248     }
3249     break;
3250   }
3251   case ISD::UDIV:
3252   case ISD::SDIV: {
3253     bool isSigned = Node->getOpcode() == ISD::SDIV;
3254     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3255     EVT VT = Node->getValueType(0);
3256     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3257       SDVTList VTs = DAG.getVTList(VT, VT);
3258       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3259                          Node->getOperand(1));
3260       Results.push_back(Tmp1);
3261     }
3262     break;
3263   }
3264   case ISD::MULHU:
3265   case ISD::MULHS: {
3266     unsigned ExpandOpcode = Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI :
3267                                                               ISD::SMUL_LOHI;
3268     EVT VT = Node->getValueType(0);
3269     SDVTList VTs = DAG.getVTList(VT, VT);
3270     assert(TLI.isOperationLegalOrCustom(ExpandOpcode, VT) &&
3271            "If this wasn't legal, it shouldn't have been created!");
3272     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3273                        Node->getOperand(1));
3274     Results.push_back(Tmp1.getValue(1));
3275     break;
3276   }
3277   case ISD::MUL: {
3278     EVT VT = Node->getValueType(0);
3279     SDVTList VTs = DAG.getVTList(VT, VT);
3280     // See if multiply or divide can be lowered using two-result operations.
3281     // We just need the low half of the multiply; try both the signed
3282     // and unsigned forms. If the target supports both SMUL_LOHI and
3283     // UMUL_LOHI, form a preference by checking which forms of plain
3284     // MULH it supports.
3285     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3286     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3287     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3288     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3289     unsigned OpToUse = 0;
3290     if (HasSMUL_LOHI && !HasMULHS) {
3291       OpToUse = ISD::SMUL_LOHI;
3292     } else if (HasUMUL_LOHI && !HasMULHU) {
3293       OpToUse = ISD::UMUL_LOHI;
3294     } else if (HasSMUL_LOHI) {
3295       OpToUse = ISD::SMUL_LOHI;
3296     } else if (HasUMUL_LOHI) {
3297       OpToUse = ISD::UMUL_LOHI;
3298     }
3299     if (OpToUse) {
3300       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3301                                     Node->getOperand(1)));
3302       break;
3303     }
3304 
3305     SDValue Lo, Hi;
3306     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3307     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3308         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3309         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3310         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3311         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG)) {
3312       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3313       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3314       SDValue Shift =
3315           DAG.getConstant(HalfType.getSizeInBits(), dl,
3316                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3317       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3318       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3319     }
3320     break;
3321   }
3322   case ISD::SADDO:
3323   case ISD::SSUBO: {
3324     SDValue LHS = Node->getOperand(0);
3325     SDValue RHS = Node->getOperand(1);
3326     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::SADDO ?
3327                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
3328                               LHS, RHS);
3329     Results.push_back(Sum);
3330     EVT ResultType = Node->getValueType(1);
3331     EVT OType = getSetCCResultType(Node->getValueType(0));
3332 
3333     SDValue Zero = DAG.getConstant(0, dl, LHS.getValueType());
3334 
3335     //   LHSSign -> LHS >= 0
3336     //   RHSSign -> RHS >= 0
3337     //   SumSign -> Sum >= 0
3338     //
3339     //   Add:
3340     //   Overflow -> (LHSSign == RHSSign) && (LHSSign != SumSign)
3341     //   Sub:
3342     //   Overflow -> (LHSSign != RHSSign) && (LHSSign != SumSign)
3343     //
3344     SDValue LHSSign = DAG.getSetCC(dl, OType, LHS, Zero, ISD::SETGE);
3345     SDValue RHSSign = DAG.getSetCC(dl, OType, RHS, Zero, ISD::SETGE);
3346     SDValue SignsMatch = DAG.getSetCC(dl, OType, LHSSign, RHSSign,
3347                                       Node->getOpcode() == ISD::SADDO ?
3348                                       ISD::SETEQ : ISD::SETNE);
3349 
3350     SDValue SumSign = DAG.getSetCC(dl, OType, Sum, Zero, ISD::SETGE);
3351     SDValue SumSignNE = DAG.getSetCC(dl, OType, LHSSign, SumSign, ISD::SETNE);
3352 
3353     SDValue Cmp = DAG.getNode(ISD::AND, dl, OType, SignsMatch, SumSignNE);
3354     Results.push_back(DAG.getBoolExtOrTrunc(Cmp, dl, ResultType, ResultType));
3355     break;
3356   }
3357   case ISD::UADDO:
3358   case ISD::USUBO: {
3359     SDValue LHS = Node->getOperand(0);
3360     SDValue RHS = Node->getOperand(1);
3361     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::UADDO ?
3362                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
3363                               LHS, RHS);
3364     Results.push_back(Sum);
3365 
3366     EVT ResultType = Node->getValueType(1);
3367     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3368     ISD::CondCode CC
3369       = Node->getOpcode() == ISD::UADDO ? ISD::SETULT : ISD::SETUGT;
3370     SDValue SetCC = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3371 
3372     Results.push_back(DAG.getBoolExtOrTrunc(SetCC, dl, ResultType, ResultType));
3373     break;
3374   }
3375   case ISD::UMULO:
3376   case ISD::SMULO: {
3377     EVT VT = Node->getValueType(0);
3378     EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
3379     SDValue LHS = Node->getOperand(0);
3380     SDValue RHS = Node->getOperand(1);
3381     SDValue BottomHalf;
3382     SDValue TopHalf;
3383     static const unsigned Ops[2][3] =
3384         { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
3385           { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
3386     bool isSigned = Node->getOpcode() == ISD::SMULO;
3387     if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
3388       BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
3389       TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
3390     } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
3391       BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
3392                                RHS);
3393       TopHalf = BottomHalf.getValue(1);
3394     } else if (TLI.isTypeLegal(WideVT)) {
3395       LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
3396       RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
3397       Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
3398       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3399                                DAG.getIntPtrConstant(0, dl));
3400       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
3401                             DAG.getIntPtrConstant(1, dl));
3402     } else {
3403       // We can fall back to a libcall with an illegal type for the MUL if we
3404       // have a libcall big enough.
3405       // Also, we can fall back to a division in some cases, but that's a big
3406       // performance hit in the general case.
3407       RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
3408       if (WideVT == MVT::i16)
3409         LC = RTLIB::MUL_I16;
3410       else if (WideVT == MVT::i32)
3411         LC = RTLIB::MUL_I32;
3412       else if (WideVT == MVT::i64)
3413         LC = RTLIB::MUL_I64;
3414       else if (WideVT == MVT::i128)
3415         LC = RTLIB::MUL_I128;
3416       assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
3417 
3418       // The high part is obtained by SRA'ing all but one of the bits of low
3419       // part.
3420       unsigned LoSize = VT.getSizeInBits();
3421       SDValue HiLHS =
3422           DAG.getNode(ISD::SRA, dl, VT, RHS,
3423                       DAG.getConstant(LoSize - 1, dl,
3424                                       TLI.getPointerTy(DAG.getDataLayout())));
3425       SDValue HiRHS =
3426           DAG.getNode(ISD::SRA, dl, VT, LHS,
3427                       DAG.getConstant(LoSize - 1, dl,
3428                                       TLI.getPointerTy(DAG.getDataLayout())));
3429 
3430       // Here we're passing the 2 arguments explicitly as 4 arguments that are
3431       // pre-lowered to the correct types. This all depends upon WideVT not
3432       // being a legal type for the architecture and thus has to be split to
3433       // two arguments.
3434       SDValue Args[] = { LHS, HiLHS, RHS, HiRHS };
3435       SDValue Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
3436       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Ret,
3437                                DAG.getIntPtrConstant(0, dl));
3438       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Ret,
3439                             DAG.getIntPtrConstant(1, dl));
3440       // Ret is a node with an illegal type. Because such things are not
3441       // generally permitted during this phase of legalization, make sure the
3442       // node has no more uses. The above EXTRACT_ELEMENT nodes should have been
3443       // folded.
3444       assert(Ret->use_empty() &&
3445              "Unexpected uses of illegally type from expanded lib call.");
3446     }
3447 
3448     if (isSigned) {
3449       Tmp1 = DAG.getConstant(
3450           VT.getSizeInBits() - 1, dl,
3451           TLI.getShiftAmountTy(BottomHalf.getValueType(), DAG.getDataLayout()));
3452       Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
3453       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf, Tmp1,
3454                              ISD::SETNE);
3455     } else {
3456       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf,
3457                              DAG.getConstant(0, dl, VT), ISD::SETNE);
3458     }
3459     Results.push_back(BottomHalf);
3460     Results.push_back(TopHalf);
3461     break;
3462   }
3463   case ISD::BUILD_PAIR: {
3464     EVT PairTy = Node->getValueType(0);
3465     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3466     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3467     Tmp2 = DAG.getNode(
3468         ISD::SHL, dl, PairTy, Tmp2,
3469         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3470                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3471     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3472     break;
3473   }
3474   case ISD::SELECT:
3475     Tmp1 = Node->getOperand(0);
3476     Tmp2 = Node->getOperand(1);
3477     Tmp3 = Node->getOperand(2);
3478     if (Tmp1.getOpcode() == ISD::SETCC) {
3479       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3480                              Tmp2, Tmp3,
3481                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3482     } else {
3483       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3484                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3485                              Tmp2, Tmp3, ISD::SETNE);
3486     }
3487     Results.push_back(Tmp1);
3488     break;
3489   case ISD::BR_JT: {
3490     SDValue Chain = Node->getOperand(0);
3491     SDValue Table = Node->getOperand(1);
3492     SDValue Index = Node->getOperand(2);
3493 
3494     EVT PTy = TLI.getPointerTy(DAG.getDataLayout());
3495 
3496     const DataLayout &TD = DAG.getDataLayout();
3497     unsigned EntrySize =
3498       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3499 
3500     Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3501                         DAG.getConstant(EntrySize, dl, Index.getValueType()));
3502     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3503                                Index, Table);
3504 
3505     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3506     SDValue LD = DAG.getExtLoad(
3507         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3508         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT,
3509         false, false, false, 0);
3510     Addr = LD;
3511     if (TM.isPositionIndependent()) {
3512       // For PIC, the sequence is:
3513       // BRIND(load(Jumptable + index) + RelocBase)
3514       // RelocBase can be JumpTable, GOT or some sort of global base.
3515       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3516                           TLI.getPICJumpTableRelocBase(Table, DAG));
3517     }
3518     Tmp1 = DAG.getNode(ISD::BRIND, dl, MVT::Other, LD.getValue(1), Addr);
3519     Results.push_back(Tmp1);
3520     break;
3521   }
3522   case ISD::BRCOND:
3523     // Expand brcond's setcc into its constituent parts and create a BR_CC
3524     // Node.
3525     Tmp1 = Node->getOperand(0);
3526     Tmp2 = Node->getOperand(1);
3527     if (Tmp2.getOpcode() == ISD::SETCC) {
3528       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3529                          Tmp1, Tmp2.getOperand(2),
3530                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3531                          Node->getOperand(2));
3532     } else {
3533       // We test only the i1 bit.  Skip the AND if UNDEF.
3534       Tmp3 = (Tmp2.isUndef()) ? Tmp2 :
3535         DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3536                     DAG.getConstant(1, dl, Tmp2.getValueType()));
3537       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3538                          DAG.getCondCode(ISD::SETNE), Tmp3,
3539                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3540                          Node->getOperand(2));
3541     }
3542     Results.push_back(Tmp1);
3543     break;
3544   case ISD::SETCC: {
3545     Tmp1 = Node->getOperand(0);
3546     Tmp2 = Node->getOperand(1);
3547     Tmp3 = Node->getOperand(2);
3548     bool Legalized = LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2,
3549                                            Tmp3, NeedInvert, dl);
3550 
3551     if (Legalized) {
3552       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3553       // condition code, create a new SETCC node.
3554       if (Tmp3.getNode())
3555         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3556                            Tmp1, Tmp2, Tmp3);
3557 
3558       // If we expanded the SETCC by inverting the condition code, then wrap
3559       // the existing SETCC in a NOT to restore the intended condition.
3560       if (NeedInvert)
3561         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3562 
3563       Results.push_back(Tmp1);
3564       break;
3565     }
3566 
3567     // Otherwise, SETCC for the given comparison type must be completely
3568     // illegal; expand it into a SELECT_CC.
3569     EVT VT = Node->getValueType(0);
3570     int TrueValue;
3571     switch (TLI.getBooleanContents(Tmp1->getValueType(0))) {
3572     case TargetLowering::ZeroOrOneBooleanContent:
3573     case TargetLowering::UndefinedBooleanContent:
3574       TrueValue = 1;
3575       break;
3576     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3577       TrueValue = -1;
3578       break;
3579     }
3580     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3581                        DAG.getConstant(TrueValue, dl, VT),
3582                        DAG.getConstant(0, dl, VT),
3583                        Tmp3);
3584     Results.push_back(Tmp1);
3585     break;
3586   }
3587   case ISD::SELECT_CC: {
3588     Tmp1 = Node->getOperand(0);   // LHS
3589     Tmp2 = Node->getOperand(1);   // RHS
3590     Tmp3 = Node->getOperand(2);   // True
3591     Tmp4 = Node->getOperand(3);   // False
3592     EVT VT = Node->getValueType(0);
3593     SDValue CC = Node->getOperand(4);
3594     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3595 
3596     if (TLI.isCondCodeLegal(CCOp, Tmp1.getSimpleValueType())) {
3597       // If the condition code is legal, then we need to expand this
3598       // node using SETCC and SELECT.
3599       EVT CmpVT = Tmp1.getValueType();
3600       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3601              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3602              "expanded.");
3603       EVT CCVT =
3604           TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), CmpVT);
3605       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC);
3606       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3607       break;
3608     }
3609 
3610     // SELECT_CC is legal, so the condition code must not be.
3611     bool Legalized = false;
3612     // Try to legalize by inverting the condition.  This is for targets that
3613     // might support an ordered version of a condition, but not the unordered
3614     // version (or vice versa).
3615     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp,
3616                                                Tmp1.getValueType().isInteger());
3617     if (TLI.isCondCodeLegal(InvCC, Tmp1.getSimpleValueType())) {
3618       // Use the new condition code and swap true and false
3619       Legalized = true;
3620       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3621     } else {
3622       // If The inverse is not legal, then try to swap the arguments using
3623       // the inverse condition code.
3624       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3625       if (TLI.isCondCodeLegal(SwapInvCC, Tmp1.getSimpleValueType())) {
3626         // The swapped inverse condition is legal, so swap true and false,
3627         // lhs and rhs.
3628         Legalized = true;
3629         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3630       }
3631     }
3632 
3633     if (!Legalized) {
3634       Legalized = LegalizeSetCCCondCode(
3635           getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC, NeedInvert,
3636           dl);
3637 
3638       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3639 
3640       // If we expanded the SETCC by inverting the condition code, then swap
3641       // the True/False operands to match.
3642       if (NeedInvert)
3643         std::swap(Tmp3, Tmp4);
3644 
3645       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3646       // condition code, create a new SELECT_CC node.
3647       if (CC.getNode()) {
3648         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3649                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3650       } else {
3651         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3652         CC = DAG.getCondCode(ISD::SETNE);
3653         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3654                            Tmp2, Tmp3, Tmp4, CC);
3655       }
3656     }
3657     Results.push_back(Tmp1);
3658     break;
3659   }
3660   case ISD::BR_CC: {
3661     Tmp1 = Node->getOperand(0);              // Chain
3662     Tmp2 = Node->getOperand(2);              // LHS
3663     Tmp3 = Node->getOperand(3);              // RHS
3664     Tmp4 = Node->getOperand(1);              // CC
3665 
3666     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
3667         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, NeedInvert, dl);
3668     (void)Legalized;
3669     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3670 
3671     // If we expanded the SETCC by inverting the condition code, then wrap
3672     // the existing SETCC in a NOT to restore the intended condition.
3673     if (NeedInvert)
3674       Tmp4 = DAG.getNOT(dl, Tmp4, Tmp4->getValueType(0));
3675 
3676     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3677     // node.
3678     if (Tmp4.getNode()) {
3679       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3680                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3681     } else {
3682       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3683       Tmp4 = DAG.getCondCode(ISD::SETNE);
3684       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3685                          Tmp2, Tmp3, Node->getOperand(4));
3686     }
3687     Results.push_back(Tmp1);
3688     break;
3689   }
3690   case ISD::BUILD_VECTOR:
3691     Results.push_back(ExpandBUILD_VECTOR(Node));
3692     break;
3693   case ISD::SRA:
3694   case ISD::SRL:
3695   case ISD::SHL: {
3696     // Scalarize vector SRA/SRL/SHL.
3697     EVT VT = Node->getValueType(0);
3698     assert(VT.isVector() && "Unable to legalize non-vector shift");
3699     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3700     unsigned NumElem = VT.getVectorNumElements();
3701 
3702     SmallVector<SDValue, 8> Scalars;
3703     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3704       SDValue Ex = DAG.getNode(
3705           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(0),
3706           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3707       SDValue Sh = DAG.getNode(
3708           ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(), Node->getOperand(1),
3709           DAG.getConstant(Idx, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
3710       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3711                                     VT.getScalarType(), Ex, Sh));
3712     }
3713     SDValue Result =
3714       DAG.getNode(ISD::BUILD_VECTOR, dl, Node->getValueType(0), Scalars);
3715     ReplaceNode(SDValue(Node, 0), Result);
3716     break;
3717   }
3718   case ISD::GLOBAL_OFFSET_TABLE:
3719   case ISD::GlobalAddress:
3720   case ISD::GlobalTLSAddress:
3721   case ISD::ExternalSymbol:
3722   case ISD::ConstantPool:
3723   case ISD::JumpTable:
3724   case ISD::INTRINSIC_W_CHAIN:
3725   case ISD::INTRINSIC_WO_CHAIN:
3726   case ISD::INTRINSIC_VOID:
3727     // FIXME: Custom lowering for these operations shouldn't return null!
3728     break;
3729   }
3730 
3731   // Replace the original node with the legalized result.
3732   if (Results.empty())
3733     return false;
3734 
3735   ReplaceNode(Node, Results.data());
3736   return true;
3737 }
3738 
ConvertNodeToLibcall(SDNode * Node)3739 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
3740   SmallVector<SDValue, 8> Results;
3741   SDLoc dl(Node);
3742   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
3743   unsigned Opc = Node->getOpcode();
3744   switch (Opc) {
3745   case ISD::ATOMIC_FENCE: {
3746     // If the target didn't lower this, lower it to '__sync_synchronize()' call
3747     // FIXME: handle "fence singlethread" more efficiently.
3748     TargetLowering::ArgListTy Args;
3749 
3750     TargetLowering::CallLoweringInfo CLI(DAG);
3751     CLI.setDebugLoc(dl)
3752         .setChain(Node->getOperand(0))
3753         .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3754                    DAG.getExternalSymbol("__sync_synchronize",
3755                                          TLI.getPointerTy(DAG.getDataLayout())),
3756                    std::move(Args));
3757 
3758     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3759 
3760     Results.push_back(CallResult.second);
3761     break;
3762   }
3763   // By default, atomic intrinsics are marked Legal and lowered. Targets
3764   // which don't support them directly, however, may want libcalls, in which
3765   // case they mark them Expand, and we get here.
3766   case ISD::ATOMIC_SWAP:
3767   case ISD::ATOMIC_LOAD_ADD:
3768   case ISD::ATOMIC_LOAD_SUB:
3769   case ISD::ATOMIC_LOAD_AND:
3770   case ISD::ATOMIC_LOAD_OR:
3771   case ISD::ATOMIC_LOAD_XOR:
3772   case ISD::ATOMIC_LOAD_NAND:
3773   case ISD::ATOMIC_LOAD_MIN:
3774   case ISD::ATOMIC_LOAD_MAX:
3775   case ISD::ATOMIC_LOAD_UMIN:
3776   case ISD::ATOMIC_LOAD_UMAX:
3777   case ISD::ATOMIC_CMP_SWAP: {
3778     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
3779     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
3780     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
3781 
3782     std::pair<SDValue, SDValue> Tmp = ExpandChainLibCall(LC, Node, false);
3783     Results.push_back(Tmp.first);
3784     Results.push_back(Tmp.second);
3785     break;
3786   }
3787   case ISD::TRAP: {
3788     // If this operation is not supported, lower it to 'abort()' call
3789     TargetLowering::ArgListTy Args;
3790     TargetLowering::CallLoweringInfo CLI(DAG);
3791     CLI.setDebugLoc(dl)
3792         .setChain(Node->getOperand(0))
3793         .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
3794                    DAG.getExternalSymbol("abort",
3795                                          TLI.getPointerTy(DAG.getDataLayout())),
3796                    std::move(Args));
3797     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
3798 
3799     Results.push_back(CallResult.second);
3800     break;
3801   }
3802   case ISD::FMINNUM:
3803     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
3804                                       RTLIB::FMIN_F80, RTLIB::FMIN_F128,
3805                                       RTLIB::FMIN_PPCF128));
3806     break;
3807   case ISD::FMAXNUM:
3808     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
3809                                       RTLIB::FMAX_F80, RTLIB::FMAX_F128,
3810                                       RTLIB::FMAX_PPCF128));
3811     break;
3812   case ISD::FSQRT:
3813     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
3814                                       RTLIB::SQRT_F80, RTLIB::SQRT_F128,
3815                                       RTLIB::SQRT_PPCF128));
3816     break;
3817   case ISD::FSIN:
3818     Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
3819                                       RTLIB::SIN_F80, RTLIB::SIN_F128,
3820                                       RTLIB::SIN_PPCF128));
3821     break;
3822   case ISD::FCOS:
3823     Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
3824                                       RTLIB::COS_F80, RTLIB::COS_F128,
3825                                       RTLIB::COS_PPCF128));
3826     break;
3827   case ISD::FSINCOS:
3828     // Expand into sincos libcall.
3829     ExpandSinCosLibCall(Node, Results);
3830     break;
3831   case ISD::FLOG:
3832     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
3833                                       RTLIB::LOG_F80, RTLIB::LOG_F128,
3834                                       RTLIB::LOG_PPCF128));
3835     break;
3836   case ISD::FLOG2:
3837     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
3838                                       RTLIB::LOG2_F80, RTLIB::LOG2_F128,
3839                                       RTLIB::LOG2_PPCF128));
3840     break;
3841   case ISD::FLOG10:
3842     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
3843                                       RTLIB::LOG10_F80, RTLIB::LOG10_F128,
3844                                       RTLIB::LOG10_PPCF128));
3845     break;
3846   case ISD::FEXP:
3847     Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
3848                                       RTLIB::EXP_F80, RTLIB::EXP_F128,
3849                                       RTLIB::EXP_PPCF128));
3850     break;
3851   case ISD::FEXP2:
3852     Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
3853                                       RTLIB::EXP2_F80, RTLIB::EXP2_F128,
3854                                       RTLIB::EXP2_PPCF128));
3855     break;
3856   case ISD::FTRUNC:
3857     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
3858                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
3859                                       RTLIB::TRUNC_PPCF128));
3860     break;
3861   case ISD::FFLOOR:
3862     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
3863                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
3864                                       RTLIB::FLOOR_PPCF128));
3865     break;
3866   case ISD::FCEIL:
3867     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
3868                                       RTLIB::CEIL_F80, RTLIB::CEIL_F128,
3869                                       RTLIB::CEIL_PPCF128));
3870     break;
3871   case ISD::FRINT:
3872     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
3873                                       RTLIB::RINT_F80, RTLIB::RINT_F128,
3874                                       RTLIB::RINT_PPCF128));
3875     break;
3876   case ISD::FNEARBYINT:
3877     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
3878                                       RTLIB::NEARBYINT_F64,
3879                                       RTLIB::NEARBYINT_F80,
3880                                       RTLIB::NEARBYINT_F128,
3881                                       RTLIB::NEARBYINT_PPCF128));
3882     break;
3883   case ISD::FROUND:
3884     Results.push_back(ExpandFPLibCall(Node, RTLIB::ROUND_F32,
3885                                       RTLIB::ROUND_F64,
3886                                       RTLIB::ROUND_F80,
3887                                       RTLIB::ROUND_F128,
3888                                       RTLIB::ROUND_PPCF128));
3889     break;
3890   case ISD::FPOWI:
3891     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
3892                                       RTLIB::POWI_F80, RTLIB::POWI_F128,
3893                                       RTLIB::POWI_PPCF128));
3894     break;
3895   case ISD::FPOW:
3896     Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
3897                                       RTLIB::POW_F80, RTLIB::POW_F128,
3898                                       RTLIB::POW_PPCF128));
3899     break;
3900   case ISD::FDIV:
3901     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
3902                                       RTLIB::DIV_F80, RTLIB::DIV_F128,
3903                                       RTLIB::DIV_PPCF128));
3904     break;
3905   case ISD::FREM:
3906     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
3907                                       RTLIB::REM_F80, RTLIB::REM_F128,
3908                                       RTLIB::REM_PPCF128));
3909     break;
3910   case ISD::FMA:
3911     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
3912                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
3913                                       RTLIB::FMA_PPCF128));
3914     break;
3915   case ISD::FADD:
3916     Results.push_back(ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
3917                                       RTLIB::ADD_F80, RTLIB::ADD_F128,
3918                                       RTLIB::ADD_PPCF128));
3919     break;
3920   case ISD::FMUL:
3921     Results.push_back(ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
3922                                       RTLIB::MUL_F80, RTLIB::MUL_F128,
3923                                       RTLIB::MUL_PPCF128));
3924     break;
3925   case ISD::FP16_TO_FP:
3926     if (Node->getValueType(0) == MVT::f32) {
3927       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
3928     }
3929     break;
3930   case ISD::FP_TO_FP16: {
3931     RTLIB::Libcall LC =
3932         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
3933     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
3934     Results.push_back(ExpandLibCall(LC, Node, false));
3935     break;
3936   }
3937   case ISD::FSUB:
3938     Results.push_back(ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
3939                                       RTLIB::SUB_F80, RTLIB::SUB_F128,
3940                                       RTLIB::SUB_PPCF128));
3941     break;
3942   case ISD::SREM:
3943     Results.push_back(ExpandIntLibCall(Node, true,
3944                                        RTLIB::SREM_I8,
3945                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
3946                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
3947     break;
3948   case ISD::UREM:
3949     Results.push_back(ExpandIntLibCall(Node, false,
3950                                        RTLIB::UREM_I8,
3951                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
3952                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
3953     break;
3954   case ISD::SDIV:
3955     Results.push_back(ExpandIntLibCall(Node, true,
3956                                        RTLIB::SDIV_I8,
3957                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
3958                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
3959     break;
3960   case ISD::UDIV:
3961     Results.push_back(ExpandIntLibCall(Node, false,
3962                                        RTLIB::UDIV_I8,
3963                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
3964                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
3965     break;
3966   case ISD::SDIVREM:
3967   case ISD::UDIVREM:
3968     // Expand into divrem libcall
3969     ExpandDivRemLibCall(Node, Results);
3970     break;
3971   case ISD::MUL:
3972     Results.push_back(ExpandIntLibCall(Node, false,
3973                                        RTLIB::MUL_I8,
3974                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
3975                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
3976     break;
3977   }
3978 
3979   // Replace the original node with the legalized result.
3980   if (!Results.empty())
3981     ReplaceNode(Node, Results.data());
3982 }
3983 
3984 // Determine the vector type to use in place of an original scalar element when
3985 // promoting equally sized vectors.
getPromotedVectorElementType(const TargetLowering & TLI,MVT EltVT,MVT NewEltVT)3986 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
3987                                         MVT EltVT, MVT NewEltVT) {
3988   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
3989   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
3990   assert(TLI.isTypeLegal(MidVT) && "unexpected");
3991   return MidVT;
3992 }
3993 
PromoteNode(SDNode * Node)3994 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
3995   SmallVector<SDValue, 8> Results;
3996   MVT OVT = Node->getSimpleValueType(0);
3997   if (Node->getOpcode() == ISD::UINT_TO_FP ||
3998       Node->getOpcode() == ISD::SINT_TO_FP ||
3999       Node->getOpcode() == ISD::SETCC ||
4000       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4001       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4002     OVT = Node->getOperand(0).getSimpleValueType();
4003   }
4004   if (Node->getOpcode() == ISD::BR_CC)
4005     OVT = Node->getOperand(2).getSimpleValueType();
4006   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4007   SDLoc dl(Node);
4008   SDValue Tmp1, Tmp2, Tmp3;
4009   switch (Node->getOpcode()) {
4010   case ISD::CTTZ:
4011   case ISD::CTTZ_ZERO_UNDEF:
4012   case ISD::CTLZ:
4013   case ISD::CTLZ_ZERO_UNDEF:
4014   case ISD::CTPOP:
4015     // Zero extend the argument.
4016     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4017     if (Node->getOpcode() == ISD::CTTZ) {
4018       // The count is the same in the promoted type except if the original
4019       // value was zero.  This can be handled by setting the bit just off
4020       // the top of the original type.
4021       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4022                                         OVT.getSizeInBits());
4023       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4024                          DAG.getConstant(TopBit, dl, NVT));
4025     }
4026     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4027     // already the correct result.
4028     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4029     if (Node->getOpcode() == ISD::CTLZ ||
4030         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4031       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4032       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4033                           DAG.getConstant(NVT.getSizeInBits() -
4034                                           OVT.getSizeInBits(), dl, NVT));
4035     }
4036     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4037     break;
4038   case ISD::BSWAP: {
4039     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4040     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4041     Tmp1 = DAG.getNode(ISD::BSWAP, dl, NVT, Tmp1);
4042     Tmp1 = DAG.getNode(
4043         ISD::SRL, dl, NVT, Tmp1,
4044         DAG.getConstant(DiffBits, dl,
4045                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4046     Results.push_back(Tmp1);
4047     break;
4048   }
4049   case ISD::FP_TO_UINT:
4050   case ISD::FP_TO_SINT:
4051     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
4052                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
4053     Results.push_back(Tmp1);
4054     break;
4055   case ISD::UINT_TO_FP:
4056   case ISD::SINT_TO_FP:
4057     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
4058                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
4059     Results.push_back(Tmp1);
4060     break;
4061   case ISD::VAARG: {
4062     SDValue Chain = Node->getOperand(0); // Get the chain.
4063     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4064 
4065     unsigned TruncOp;
4066     if (OVT.isVector()) {
4067       TruncOp = ISD::BITCAST;
4068     } else {
4069       assert(OVT.isInteger()
4070         && "VAARG promotion is supported only for vectors or integer types");
4071       TruncOp = ISD::TRUNCATE;
4072     }
4073 
4074     // Perform the larger operation, then convert back
4075     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4076              Node->getConstantOperandVal(3));
4077     Chain = Tmp1.getValue(1);
4078 
4079     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4080 
4081     // Modified the chain result - switch anything that used the old chain to
4082     // use the new one.
4083     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4084     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4085     if (UpdatedNodes) {
4086       UpdatedNodes->insert(Tmp2.getNode());
4087       UpdatedNodes->insert(Chain.getNode());
4088     }
4089     ReplacedNode(Node);
4090     break;
4091   }
4092   case ISD::AND:
4093   case ISD::OR:
4094   case ISD::XOR: {
4095     unsigned ExtOp, TruncOp;
4096     if (OVT.isVector()) {
4097       ExtOp   = ISD::BITCAST;
4098       TruncOp = ISD::BITCAST;
4099     } else {
4100       assert(OVT.isInteger() && "Cannot promote logic operation");
4101       ExtOp   = ISD::ANY_EXTEND;
4102       TruncOp = ISD::TRUNCATE;
4103     }
4104     // Promote each of the values to the new type.
4105     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4106     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4107     // Perform the larger operation, then convert back
4108     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4109     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4110     break;
4111   }
4112   case ISD::SELECT: {
4113     unsigned ExtOp, TruncOp;
4114     if (Node->getValueType(0).isVector() ||
4115         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4116       ExtOp   = ISD::BITCAST;
4117       TruncOp = ISD::BITCAST;
4118     } else if (Node->getValueType(0).isInteger()) {
4119       ExtOp   = ISD::ANY_EXTEND;
4120       TruncOp = ISD::TRUNCATE;
4121     } else {
4122       ExtOp   = ISD::FP_EXTEND;
4123       TruncOp = ISD::FP_ROUND;
4124     }
4125     Tmp1 = Node->getOperand(0);
4126     // Promote each of the values to the new type.
4127     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4128     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4129     // Perform the larger operation, then round down.
4130     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4131     if (TruncOp != ISD::FP_ROUND)
4132       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4133     else
4134       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4135                          DAG.getIntPtrConstant(0, dl));
4136     Results.push_back(Tmp1);
4137     break;
4138   }
4139   case ISD::VECTOR_SHUFFLE: {
4140     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4141 
4142     // Cast the two input vectors.
4143     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4144     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4145 
4146     // Convert the shuffle mask to the right # elements.
4147     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4148     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4149     Results.push_back(Tmp1);
4150     break;
4151   }
4152   case ISD::SETCC: {
4153     unsigned ExtOp = ISD::FP_EXTEND;
4154     if (NVT.isInteger()) {
4155       ISD::CondCode CCCode =
4156         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4157       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4158     }
4159     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4160     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4161     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
4162                                   Tmp1, Tmp2, Node->getOperand(2)));
4163     break;
4164   }
4165   case ISD::BR_CC: {
4166     unsigned ExtOp = ISD::FP_EXTEND;
4167     if (NVT.isInteger()) {
4168       ISD::CondCode CCCode =
4169         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4170       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4171     }
4172     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4173     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4174     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4175                                   Node->getOperand(0), Node->getOperand(1),
4176                                   Tmp1, Tmp2, Node->getOperand(4)));
4177     break;
4178   }
4179   case ISD::FADD:
4180   case ISD::FSUB:
4181   case ISD::FMUL:
4182   case ISD::FDIV:
4183   case ISD::FREM:
4184   case ISD::FMINNUM:
4185   case ISD::FMAXNUM:
4186   case ISD::FPOW: {
4187     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4188     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4189     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4190                        Node->getFlags());
4191     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4192                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4193     break;
4194   }
4195   case ISD::FMA: {
4196     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4197     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4198     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4199     Results.push_back(
4200         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4201                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4202                     DAG.getIntPtrConstant(0, dl)));
4203     break;
4204   }
4205   case ISD::FCOPYSIGN:
4206   case ISD::FPOWI: {
4207     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4208     Tmp2 = Node->getOperand(1);
4209     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4210 
4211     // fcopysign doesn't change anything but the sign bit, so
4212     //   (fp_round (fcopysign (fpext a), b))
4213     // is as precise as
4214     //   (fp_round (fpext a))
4215     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4216     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4217     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4218                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4219     break;
4220   }
4221   case ISD::FFLOOR:
4222   case ISD::FCEIL:
4223   case ISD::FRINT:
4224   case ISD::FNEARBYINT:
4225   case ISD::FROUND:
4226   case ISD::FTRUNC:
4227   case ISD::FNEG:
4228   case ISD::FSQRT:
4229   case ISD::FSIN:
4230   case ISD::FCOS:
4231   case ISD::FLOG:
4232   case ISD::FLOG2:
4233   case ISD::FLOG10:
4234   case ISD::FABS:
4235   case ISD::FEXP:
4236   case ISD::FEXP2: {
4237     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4238     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4239     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4240                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4241     break;
4242   }
4243   case ISD::BUILD_VECTOR: {
4244     MVT EltVT = OVT.getVectorElementType();
4245     MVT NewEltVT = NVT.getVectorElementType();
4246 
4247     // Handle bitcasts to a different vector type with the same total bit size
4248     //
4249     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4250     //  =>
4251     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4252 
4253     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4254            "Invalid promote type for build_vector");
4255     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4256 
4257     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4258 
4259     SmallVector<SDValue, 8> NewOps;
4260     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4261       SDValue Op = Node->getOperand(I);
4262       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4263     }
4264 
4265     SDLoc SL(Node);
4266     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4267     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4268     Results.push_back(CvtVec);
4269     break;
4270   }
4271   case ISD::EXTRACT_VECTOR_ELT: {
4272     MVT EltVT = OVT.getVectorElementType();
4273     MVT NewEltVT = NVT.getVectorElementType();
4274 
4275     // Handle bitcasts to a different vector type with the same total bit size.
4276     //
4277     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4278     //  =>
4279     //  v4i32:castx = bitcast x:v2i64
4280     //
4281     // i64 = bitcast
4282     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4283     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4284     //
4285 
4286     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4287            "Invalid promote type for extract_vector_elt");
4288     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4289 
4290     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4291     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4292 
4293     SDValue Idx = Node->getOperand(1);
4294     EVT IdxVT = Idx.getValueType();
4295     SDLoc SL(Node);
4296     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4297     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4298 
4299     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4300 
4301     SmallVector<SDValue, 8> NewOps;
4302     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4303       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4304       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4305 
4306       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4307                                 CastVec, TmpIdx);
4308       NewOps.push_back(Elt);
4309     }
4310 
4311     SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, SL, MidVT, NewOps);
4312 
4313     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4314     break;
4315   }
4316   case ISD::INSERT_VECTOR_ELT: {
4317     MVT EltVT = OVT.getVectorElementType();
4318     MVT NewEltVT = NVT.getVectorElementType();
4319 
4320     // Handle bitcasts to a different vector type with the same total bit size
4321     //
4322     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4323     //  =>
4324     //  v4i32:castx = bitcast x:v2i64
4325     //  v2i32:casty = bitcast y:i64
4326     //
4327     // v2i64 = bitcast
4328     //   (v4i32 insert_vector_elt
4329     //       (v4i32 insert_vector_elt v4i32:castx,
4330     //                                (extract_vector_elt casty, 0), 2 * z),
4331     //        (extract_vector_elt casty, 1), (2 * z + 1))
4332 
4333     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4334            "Invalid promote type for insert_vector_elt");
4335     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4336 
4337     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4338     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4339 
4340     SDValue Val = Node->getOperand(1);
4341     SDValue Idx = Node->getOperand(2);
4342     EVT IdxVT = Idx.getValueType();
4343     SDLoc SL(Node);
4344 
4345     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4346     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4347 
4348     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4349     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4350 
4351     SDValue NewVec = CastVec;
4352     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4353       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4354       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4355 
4356       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4357                                 CastVal, IdxOffset);
4358 
4359       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4360                            NewVec, Elt, InEltIdx);
4361     }
4362 
4363     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4364     break;
4365   }
4366   case ISD::SCALAR_TO_VECTOR: {
4367     MVT EltVT = OVT.getVectorElementType();
4368     MVT NewEltVT = NVT.getVectorElementType();
4369 
4370     // Handle bitcasts to different vector type with the smae total bit size.
4371     //
4372     // e.g. v2i64 = scalar_to_vector x:i64
4373     //   =>
4374     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4375     //
4376 
4377     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4378     SDValue Val = Node->getOperand(0);
4379     SDLoc SL(Node);
4380 
4381     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4382     SDValue Undef = DAG.getUNDEF(MidVT);
4383 
4384     SmallVector<SDValue, 8> NewElts;
4385     NewElts.push_back(CastVal);
4386     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4387       NewElts.push_back(Undef);
4388 
4389     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4390     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4391     Results.push_back(CvtVec);
4392     break;
4393   }
4394   }
4395 
4396   // Replace the original node with the legalized result.
4397   if (!Results.empty())
4398     ReplaceNode(Node, Results.data());
4399 }
4400 
4401 /// This is the entry point for the file.
Legalize()4402 void SelectionDAG::Legalize() {
4403   AssignTopologicalOrder();
4404 
4405   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4406   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4407 
4408   // Visit all the nodes. We start in topological order, so that we see
4409   // nodes with their original operands intact. Legalization can produce
4410   // new nodes which may themselves need to be legalized. Iterate until all
4411   // nodes have been legalized.
4412   for (;;) {
4413     bool AnyLegalized = false;
4414     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4415       --NI;
4416 
4417       SDNode *N = &*NI;
4418       if (N->use_empty() && N != getRoot().getNode()) {
4419         ++NI;
4420         DeleteNode(N);
4421         continue;
4422       }
4423 
4424       if (LegalizedNodes.insert(N).second) {
4425         AnyLegalized = true;
4426         Legalizer.LegalizeOp(N);
4427 
4428         if (N->use_empty() && N != getRoot().getNode()) {
4429           ++NI;
4430           DeleteNode(N);
4431         }
4432       }
4433     }
4434     if (!AnyLegalized)
4435       break;
4436 
4437   }
4438 
4439   // Remove dead nodes now.
4440   RemoveDeadNodes();
4441 }
4442 
LegalizeOp(SDNode * N,SmallSetVector<SDNode *,16> & UpdatedNodes)4443 bool SelectionDAG::LegalizeOp(SDNode *N,
4444                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4445   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4446   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4447 
4448   // Directly insert the node in question, and legalize it. This will recurse
4449   // as needed through operands.
4450   LegalizedNodes.insert(N);
4451   Legalizer.LegalizeOp(N);
4452 
4453   return LegalizedNodes.count(N);
4454 }
4455