• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===-- ARMISelLowering.h - ARM DAG Lowering Interface ----------*- C++ -*-===//
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 defines the interfaces that ARM uses to lower LLVM code into a
11 // selection DAG.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_LIB_TARGET_ARM_ARMISELLOWERING_H
16 #define LLVM_LIB_TARGET_ARM_ARMISELLOWERING_H
17 
18 #include "MCTargetDesc/ARMBaseInfo.h"
19 #include "llvm/CodeGen/CallingConvLower.h"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/Target/TargetLowering.h"
22 #include <vector>
23 
24 namespace llvm {
25   class ARMConstantPoolValue;
26   class ARMSubtarget;
27 
28   namespace ARMISD {
29     // ARM Specific DAG Nodes
30     enum NodeType : unsigned {
31       // Start the numbering where the builtin ops and target ops leave off.
32       FIRST_NUMBER = ISD::BUILTIN_OP_END,
33 
34       Wrapper,      // Wrapper - A wrapper node for TargetConstantPool,
35                     // TargetExternalSymbol, and TargetGlobalAddress.
36       WrapperPIC,   // WrapperPIC - A wrapper node for TargetGlobalAddress in
37                     // PIC mode.
38       WrapperJT,    // WrapperJT - A wrapper node for TargetJumpTable
39 
40       // Add pseudo op to model memcpy for struct byval.
41       COPY_STRUCT_BYVAL,
42 
43       CALL,         // Function call.
44       CALL_PRED,    // Function call that's predicable.
45       CALL_NOLINK,  // Function call with branch not branch-and-link.
46       BRCOND,       // Conditional branch.
47       BR_JT,        // Jumptable branch.
48       BR2_JT,       // Jumptable branch (2 level - jumptable entry is a jump).
49       RET_FLAG,     // Return with a flag operand.
50       INTRET_FLAG,  // Interrupt return with an LR-offset and a flag operand.
51 
52       PIC_ADD,      // Add with a PC operand and a PIC label.
53 
54       CMP,          // ARM compare instructions.
55       CMN,          // ARM CMN instructions.
56       CMPZ,         // ARM compare that sets only Z flag.
57       CMPFP,        // ARM VFP compare instruction, sets FPSCR.
58       CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
59       FMSTAT,       // ARM fmstat instruction.
60 
61       CMOV,         // ARM conditional move instructions.
62 
63       SSAT,         // Signed saturation
64 
65       BCC_i64,
66 
67       SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
68       SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
69       RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
70 
71       ADDC,         // Add with carry
72       ADDE,         // Add using carry
73       SUBC,         // Sub with carry
74       SUBE,         // Sub using carry
75 
76       VMOVRRD,      // double to two gprs.
77       VMOVDRR,      // Two gprs to double.
78 
79       EH_SJLJ_SETJMP,         // SjLj exception handling setjmp.
80       EH_SJLJ_LONGJMP,        // SjLj exception handling longjmp.
81       EH_SJLJ_SETUP_DISPATCH, // SjLj exception handling setup_dispatch.
82 
83       TC_RETURN,    // Tail call return pseudo.
84 
85       THREAD_POINTER,
86 
87       DYN_ALLOC,    // Dynamic allocation on the stack.
88 
89       MEMBARRIER_MCR, // Memory barrier (MCR)
90 
91       PRELOAD,      // Preload
92 
93       WIN__CHKSTK,  // Windows' __chkstk call to do stack probing.
94       WIN__DBZCHK,  // Windows' divide by zero check
95 
96       VCEQ,         // Vector compare equal.
97       VCEQZ,        // Vector compare equal to zero.
98       VCGE,         // Vector compare greater than or equal.
99       VCGEZ,        // Vector compare greater than or equal to zero.
100       VCLEZ,        // Vector compare less than or equal to zero.
101       VCGEU,        // Vector compare unsigned greater than or equal.
102       VCGT,         // Vector compare greater than.
103       VCGTZ,        // Vector compare greater than zero.
104       VCLTZ,        // Vector compare less than zero.
105       VCGTU,        // Vector compare unsigned greater than.
106       VTST,         // Vector test bits.
107 
108       // Vector shift by immediate:
109       VSHL,         // ...left
110       VSHRs,        // ...right (signed)
111       VSHRu,        // ...right (unsigned)
112 
113       // Vector rounding shift by immediate:
114       VRSHRs,       // ...right (signed)
115       VRSHRu,       // ...right (unsigned)
116       VRSHRN,       // ...right narrow
117 
118       // Vector saturating shift by immediate:
119       VQSHLs,       // ...left (signed)
120       VQSHLu,       // ...left (unsigned)
121       VQSHLsu,      // ...left (signed to unsigned)
122       VQSHRNs,      // ...right narrow (signed)
123       VQSHRNu,      // ...right narrow (unsigned)
124       VQSHRNsu,     // ...right narrow (signed to unsigned)
125 
126       // Vector saturating rounding shift by immediate:
127       VQRSHRNs,     // ...right narrow (signed)
128       VQRSHRNu,     // ...right narrow (unsigned)
129       VQRSHRNsu,    // ...right narrow (signed to unsigned)
130 
131       // Vector shift and insert:
132       VSLI,         // ...left
133       VSRI,         // ...right
134 
135       // Vector get lane (VMOV scalar to ARM core register)
136       // (These are used for 8- and 16-bit element types only.)
137       VGETLANEu,    // zero-extend vector extract element
138       VGETLANEs,    // sign-extend vector extract element
139 
140       // Vector move immediate and move negated immediate:
141       VMOVIMM,
142       VMVNIMM,
143 
144       // Vector move f32 immediate:
145       VMOVFPIMM,
146 
147       // Vector duplicate:
148       VDUP,
149       VDUPLANE,
150 
151       // Vector shuffles:
152       VEXT,         // extract
153       VREV64,       // reverse elements within 64-bit doublewords
154       VREV32,       // reverse elements within 32-bit words
155       VREV16,       // reverse elements within 16-bit halfwords
156       VZIP,         // zip (interleave)
157       VUZP,         // unzip (deinterleave)
158       VTRN,         // transpose
159       VTBL1,        // 1-register shuffle with mask
160       VTBL2,        // 2-register shuffle with mask
161 
162       // Vector multiply long:
163       VMULLs,       // ...signed
164       VMULLu,       // ...unsigned
165 
166       UMLAL,        // 64bit Unsigned Accumulate Multiply
167       SMLAL,        // 64bit Signed Accumulate Multiply
168       UMAAL,        // 64-bit Unsigned Accumulate Accumulate Multiply
169 
170       // Operands of the standard BUILD_VECTOR node are not legalized, which
171       // is fine if BUILD_VECTORs are always lowered to shuffles or other
172       // operations, but for ARM some BUILD_VECTORs are legal as-is and their
173       // operands need to be legalized.  Define an ARM-specific version of
174       // BUILD_VECTOR for this purpose.
175       BUILD_VECTOR,
176 
177       // Bit-field insert
178       BFI,
179 
180       // Vector OR with immediate
181       VORRIMM,
182       // Vector AND with NOT of immediate
183       VBICIMM,
184 
185       // Vector bitwise select
186       VBSL,
187 
188       // Pseudo-instruction representing a memory copy using ldm/stm
189       // instructions.
190       MEMCPY,
191 
192       // Vector load N-element structure to all lanes:
193       VLD2DUP = ISD::FIRST_TARGET_MEMORY_OPCODE,
194       VLD3DUP,
195       VLD4DUP,
196 
197       // NEON loads with post-increment base updates:
198       VLD1_UPD,
199       VLD2_UPD,
200       VLD3_UPD,
201       VLD4_UPD,
202       VLD2LN_UPD,
203       VLD3LN_UPD,
204       VLD4LN_UPD,
205       VLD2DUP_UPD,
206       VLD3DUP_UPD,
207       VLD4DUP_UPD,
208 
209       // NEON stores with post-increment base updates:
210       VST1_UPD,
211       VST2_UPD,
212       VST3_UPD,
213       VST4_UPD,
214       VST2LN_UPD,
215       VST3LN_UPD,
216       VST4LN_UPD
217     };
218   }
219 
220   /// Define some predicates that are used for node matching.
221   namespace ARM {
222     bool isBitFieldInvertedMask(unsigned v);
223   }
224 
225   //===--------------------------------------------------------------------===//
226   //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
227 
228   class ARMTargetLowering : public TargetLowering {
229   public:
230     explicit ARMTargetLowering(const TargetMachine &TM,
231                                const ARMSubtarget &STI);
232 
233     unsigned getJumpTableEncoding() const override;
234     bool useSoftFloat() const override;
235 
236     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
237 
238     /// ReplaceNodeResults - Replace the results of node with an illegal result
239     /// type with new values built out of custom code.
240     ///
241     void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
242                             SelectionDAG &DAG) const override;
243 
244     const char *getTargetNodeName(unsigned Opcode) const override;
245 
isSelectSupported(SelectSupportKind Kind)246     bool isSelectSupported(SelectSupportKind Kind) const override {
247       // ARM does not support scalar condition selects on vectors.
248       return (Kind != ScalarCondVectorVal);
249     }
250 
251     /// getSetCCResultType - Return the value type to use for ISD::SETCC.
252     EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
253                            EVT VT) const override;
254 
255     MachineBasicBlock *
256     EmitInstrWithCustomInserter(MachineInstr &MI,
257                                 MachineBasicBlock *MBB) const override;
258 
259     void AdjustInstrPostInstrSelection(MachineInstr &MI,
260                                        SDNode *Node) const override;
261 
262     SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const;
263     SDValue PerformBRCONDCombine(SDNode *N, SelectionDAG &DAG) const;
264     SDValue PerformCMOVToBFICombine(SDNode *N, SelectionDAG &DAG) const;
265     SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
266 
267     bool isDesirableToTransformToIntegerOp(unsigned Opc, EVT VT) const override;
268 
269     /// allowsMisalignedMemoryAccesses - Returns true if the target allows
270     /// unaligned memory accesses of the specified type. Returns whether it
271     /// is "fast" by reference in the second argument.
272     bool allowsMisalignedMemoryAccesses(EVT VT, unsigned AddrSpace,
273                                         unsigned Align,
274                                         bool *Fast) const override;
275 
276     EVT getOptimalMemOpType(uint64_t Size,
277                             unsigned DstAlign, unsigned SrcAlign,
278                             bool IsMemset, bool ZeroMemset,
279                             bool MemcpyStrSrc,
280                             MachineFunction &MF) const override;
281 
282     using TargetLowering::isZExtFree;
283     bool isZExtFree(SDValue Val, EVT VT2) const override;
284 
285     bool isVectorLoadExtDesirable(SDValue ExtVal) const override;
286 
287     bool allowTruncateForTailCall(Type *Ty1, Type *Ty2) const override;
288 
289 
290     /// isLegalAddressingMode - Return true if the addressing mode represented
291     /// by AM is legal for this target, for a load/store of the specified type.
292     bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM,
293                                Type *Ty, unsigned AS) const override;
294     bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
295 
296     /// isLegalICmpImmediate - Return true if the specified immediate is legal
297     /// icmp immediate, that is the target has icmp instructions which can
298     /// compare a register against the immediate without having to materialize
299     /// the immediate into a register.
300     bool isLegalICmpImmediate(int64_t Imm) const override;
301 
302     /// isLegalAddImmediate - Return true if the specified immediate is legal
303     /// add immediate, that is the target has add instructions which can
304     /// add a register and the immediate without having to materialize
305     /// the immediate into a register.
306     bool isLegalAddImmediate(int64_t Imm) const override;
307 
308     /// getPreIndexedAddressParts - returns true by value, base pointer and
309     /// offset pointer and addressing mode by reference if the node's address
310     /// can be legally represented as pre-indexed load / store address.
311     bool getPreIndexedAddressParts(SDNode *N, SDValue &Base, SDValue &Offset,
312                                    ISD::MemIndexedMode &AM,
313                                    SelectionDAG &DAG) const override;
314 
315     /// getPostIndexedAddressParts - returns true by value, base pointer and
316     /// offset pointer and addressing mode by reference if this node can be
317     /// combined with a load / store to form a post-indexed load / store.
318     bool getPostIndexedAddressParts(SDNode *N, SDNode *Op, SDValue &Base,
319                                     SDValue &Offset, ISD::MemIndexedMode &AM,
320                                     SelectionDAG &DAG) const override;
321 
322     void computeKnownBitsForTargetNode(const SDValue Op, APInt &KnownZero,
323                                        APInt &KnownOne,
324                                        const SelectionDAG &DAG,
325                                        unsigned Depth) const override;
326 
327 
328     bool ExpandInlineAsm(CallInst *CI) const override;
329 
330     ConstraintType getConstraintType(StringRef Constraint) const override;
331 
332     /// Examine constraint string and operand type and determine a weight value.
333     /// The operand object must already have been set up with the operand type.
334     ConstraintWeight getSingleConstraintMatchWeight(
335       AsmOperandInfo &info, const char *constraint) const override;
336 
337     std::pair<unsigned, const TargetRegisterClass *>
338     getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
339                                  StringRef Constraint, MVT VT) const override;
340 
341     const char *LowerXConstraint(EVT ConstraintVT) const override;
342 
343     /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
344     /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
345     /// true it means one of the asm constraint of the inline asm instruction
346     /// being processed is 'm'.
347     void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
348                                       std::vector<SDValue> &Ops,
349                                       SelectionDAG &DAG) const override;
350 
351     unsigned
getInlineAsmMemConstraint(StringRef ConstraintCode)352     getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
353       if (ConstraintCode == "Q")
354         return InlineAsm::Constraint_Q;
355       else if (ConstraintCode == "o")
356         return InlineAsm::Constraint_o;
357       else if (ConstraintCode.size() == 2) {
358         if (ConstraintCode[0] == 'U') {
359           switch(ConstraintCode[1]) {
360           default:
361             break;
362           case 'm':
363             return InlineAsm::Constraint_Um;
364           case 'n':
365             return InlineAsm::Constraint_Un;
366           case 'q':
367             return InlineAsm::Constraint_Uq;
368           case 's':
369             return InlineAsm::Constraint_Us;
370           case 't':
371             return InlineAsm::Constraint_Ut;
372           case 'v':
373             return InlineAsm::Constraint_Uv;
374           case 'y':
375             return InlineAsm::Constraint_Uy;
376           }
377         }
378       }
379       return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
380     }
381 
getSubtarget()382     const ARMSubtarget* getSubtarget() const {
383       return Subtarget;
384     }
385 
386     /// getRegClassFor - Return the register class that should be used for the
387     /// specified value type.
388     const TargetRegisterClass *getRegClassFor(MVT VT) const override;
389 
390     /// Returns true if a cast between SrcAS and DestAS is a noop.
isNoopAddrSpaceCast(unsigned SrcAS,unsigned DestAS)391     bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override {
392       // Addrspacecasts are always noops.
393       return true;
394     }
395 
396     bool shouldAlignPointerArgs(CallInst *CI, unsigned &MinSize,
397                                 unsigned &PrefAlign) const override;
398 
399     /// createFastISel - This method returns a target specific FastISel object,
400     /// or null if the target does not support "fast" ISel.
401     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
402                              const TargetLibraryInfo *libInfo) const override;
403 
404     Sched::Preference getSchedulingPreference(SDNode *N) const override;
405 
406     bool
407     isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const override;
408     bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
409 
410     /// isFPImmLegal - Returns true if the target can instruction select the
411     /// specified FP immediate natively. If false, the legalizer will
412     /// materialize the FP immediate as a load from a constant pool.
413     bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
414 
415     bool getTgtMemIntrinsic(IntrinsicInfo &Info,
416                             const CallInst &I,
417                             unsigned Intrinsic) const override;
418 
419     /// \brief Returns true if it is beneficial to convert a load of a constant
420     /// to just the constant itself.
421     bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
422                                            Type *Ty) const override;
423 
424     /// \brief Returns true if an argument of type Ty needs to be passed in a
425     /// contiguous block of registers in calling convention CallConv.
426     bool functionArgumentNeedsConsecutiveRegisters(
427         Type *Ty, CallingConv::ID CallConv, bool isVarArg) const override;
428 
429     /// If a physical register, this returns the register that receives the
430     /// exception address on entry to an EH pad.
431     unsigned
432     getExceptionPointerRegister(const Constant *PersonalityFn) const override;
433 
434     /// If a physical register, this returns the register that receives the
435     /// exception typeid on entry to a landing pad.
436     unsigned
437     getExceptionSelectorRegister(const Constant *PersonalityFn) const override;
438 
439     Instruction *makeDMB(IRBuilder<> &Builder, ARM_MB::MemBOpt Domain) const;
440     Value *emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
441                           AtomicOrdering Ord) const override;
442     Value *emitStoreConditional(IRBuilder<> &Builder, Value *Val,
443                                 Value *Addr, AtomicOrdering Ord) const override;
444 
445     void emitAtomicCmpXchgNoStoreLLBalance(IRBuilder<> &Builder) const override;
446 
447     Instruction* emitLeadingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
448                           bool IsStore, bool IsLoad) const override;
449     Instruction* emitTrailingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
450                            bool IsStore, bool IsLoad) const override;
451 
getMaxSupportedInterleaveFactor()452     unsigned getMaxSupportedInterleaveFactor() const override { return 4; }
453 
454     bool lowerInterleavedLoad(LoadInst *LI,
455                               ArrayRef<ShuffleVectorInst *> Shuffles,
456                               ArrayRef<unsigned> Indices,
457                               unsigned Factor) const override;
458     bool lowerInterleavedStore(StoreInst *SI, ShuffleVectorInst *SVI,
459                                unsigned Factor) const override;
460 
461     bool shouldInsertFencesForAtomic(const Instruction *I) const override;
462     TargetLoweringBase::AtomicExpansionKind
463     shouldExpandAtomicLoadInIR(LoadInst *LI) const override;
464     bool shouldExpandAtomicStoreInIR(StoreInst *SI) const override;
465     TargetLoweringBase::AtomicExpansionKind
466     shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
467     bool shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst *AI) const override;
468 
469     bool useLoadStackGuardNode() const override;
470 
471     bool canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
472                                    unsigned &Cost) const override;
473 
474     bool isCheapToSpeculateCttz() const override;
475     bool isCheapToSpeculateCtlz() const override;
476 
supportSwiftError()477     bool supportSwiftError() const override {
478       return true;
479     }
480 
481   protected:
482     std::pair<const TargetRegisterClass *, uint8_t>
483     findRepresentativeClass(const TargetRegisterInfo *TRI,
484                             MVT VT) const override;
485 
486   private:
487     /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
488     /// make the right decision when generating code for different targets.
489     const ARMSubtarget *Subtarget;
490 
491     const TargetRegisterInfo *RegInfo;
492 
493     const InstrItineraryData *Itins;
494 
495     /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
496     ///
497     unsigned ARMPCLabelIndex;
498 
499     // TODO: remove this, and have shouldInsertFencesForAtomic do the proper
500     // check.
501     bool InsertFencesForAtomic;
502 
503     void addTypeForNEON(MVT VT, MVT PromotedLdStVT, MVT PromotedBitwiseVT);
504     void addDRTypeForNEON(MVT VT);
505     void addQRTypeForNEON(MVT VT);
506     std::pair<SDValue, SDValue> getARMXALUOOp(SDValue Op, SelectionDAG &DAG, SDValue &ARMcc) const;
507 
508     typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
509     void PassF64ArgInRegs(const SDLoc &dl, SelectionDAG &DAG, SDValue Chain,
510                           SDValue &Arg, RegsToPassVector &RegsToPass,
511                           CCValAssign &VA, CCValAssign &NextVA,
512                           SDValue &StackPtr,
513                           SmallVectorImpl<SDValue> &MemOpChains,
514                           ISD::ArgFlagsTy Flags) const;
515     SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
516                                  SDValue &Root, SelectionDAG &DAG,
517                                  const SDLoc &dl) const;
518 
519     CallingConv::ID getEffectiveCallingConv(CallingConv::ID CC,
520                                             bool isVarArg) const;
521     CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
522                                   bool isVarArg) const;
523     SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
524                              const SDLoc &dl, SelectionDAG &DAG,
525                              const CCValAssign &VA,
526                              ISD::ArgFlagsTy Flags) const;
527     SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
528     SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
529     SDValue LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op, SelectionDAG &DAG) const;
530     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
531                                     const ARMSubtarget *Subtarget) const;
532     SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
533     SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
534     SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
535     SDValue LowerGlobalAddressWindows(SDValue Op, SelectionDAG &DAG) const;
536     SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
537     SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
538                                             SelectionDAG &DAG) const;
539     SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
540                                  SelectionDAG &DAG,
541                                  TLSModel::Model model) const;
542     SDValue LowerGlobalTLSAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
543     SDValue LowerGlobalTLSAddressWindows(SDValue Op, SelectionDAG &DAG) const;
544     SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
545     SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
546     SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) const;
547     SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
548     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
549     SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
550     SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
551     SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
552     SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
553     SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
554     SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
555     SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
556     SDValue LowerConstantFP(SDValue Op, SelectionDAG &DAG,
557                             const ARMSubtarget *ST) const;
558     SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
559                               const ARMSubtarget *ST) const;
560     SDValue LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const;
561     SDValue LowerDivRem(SDValue Op, SelectionDAG &DAG) const;
562     SDValue LowerDIV_Windows(SDValue Op, SelectionDAG &DAG, bool Signed) const;
563     void ExpandDIV_Windows(SDValue Op, SelectionDAG &DAG, bool Signed,
564                            SmallVectorImpl<SDValue> &Results) const;
565     SDValue LowerWindowsDIVLibCall(SDValue Op, SelectionDAG &DAG, bool Signed,
566                                    SDValue &Chain) const;
567     SDValue LowerREM(SDNode *N, SelectionDAG &DAG) const;
568     SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
569     SDValue LowerFP_ROUND(SDValue Op, SelectionDAG &DAG) const;
570     SDValue LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) const;
571     SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) const;
572     SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
573 
574     unsigned getRegisterByName(const char* RegName, EVT VT,
575                                SelectionDAG &DAG) const override;
576 
577     /// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
578     /// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
579     /// expanded to FMAs when this method returns true, otherwise fmuladd is
580     /// expanded to fmul + fadd.
581     ///
582     /// ARM supports both fused and unfused multiply-add operations; we already
583     /// lower a pair of fmul and fadd to the latter so it's not clear that there
584     /// would be a gain or that the gain would be worthwhile enough to risk
585     /// correctness bugs.
isFMAFasterThanFMulAndFAdd(EVT VT)586     bool isFMAFasterThanFMulAndFAdd(EVT VT) const override { return false; }
587 
588     SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
589 
590     SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
591                             CallingConv::ID CallConv, bool isVarArg,
592                             const SmallVectorImpl<ISD::InputArg> &Ins,
593                             const SDLoc &dl, SelectionDAG &DAG,
594                             SmallVectorImpl<SDValue> &InVals, bool isThisReturn,
595                             SDValue ThisVal) const;
596 
supportSplitCSR(MachineFunction * MF)597     bool supportSplitCSR(MachineFunction *MF) const override {
598       return MF->getFunction()->getCallingConv() == CallingConv::CXX_FAST_TLS &&
599           MF->getFunction()->hasFnAttribute(Attribute::NoUnwind);
600     }
601     void initializeSplitCSR(MachineBasicBlock *Entry) const override;
602     void insertCopiesSplitCSR(
603       MachineBasicBlock *Entry,
604       const SmallVectorImpl<MachineBasicBlock *> &Exits) const override;
605 
606     SDValue
607     LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
608                          const SmallVectorImpl<ISD::InputArg> &Ins,
609                          const SDLoc &dl, SelectionDAG &DAG,
610                          SmallVectorImpl<SDValue> &InVals) const override;
611 
612     int StoreByValRegs(CCState &CCInfo, SelectionDAG &DAG, const SDLoc &dl,
613                        SDValue &Chain, const Value *OrigArg,
614                        unsigned InRegsParamRecordIdx, int ArgOffset,
615                        unsigned ArgSize) const;
616 
617     void VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
618                               const SDLoc &dl, SDValue &Chain,
619                               unsigned ArgOffset, unsigned TotalArgRegsSaveSize,
620                               bool ForceMutable = false) const;
621 
622     SDValue
623       LowerCall(TargetLowering::CallLoweringInfo &CLI,
624                 SmallVectorImpl<SDValue> &InVals) const override;
625 
626     /// HandleByVal - Target-specific cleanup for ByVal support.
627     void HandleByVal(CCState *, unsigned &, unsigned) const override;
628 
629     /// IsEligibleForTailCallOptimization - Check whether the call is eligible
630     /// for tail call optimization. Targets which want to do tail call
631     /// optimization should implement this function.
632     bool IsEligibleForTailCallOptimization(SDValue Callee,
633                                            CallingConv::ID CalleeCC,
634                                            bool isVarArg,
635                                            bool isCalleeStructRet,
636                                            bool isCallerStructRet,
637                                     const SmallVectorImpl<ISD::OutputArg> &Outs,
638                                     const SmallVectorImpl<SDValue> &OutVals,
639                                     const SmallVectorImpl<ISD::InputArg> &Ins,
640                                            SelectionDAG& DAG) const;
641 
642     bool CanLowerReturn(CallingConv::ID CallConv,
643                         MachineFunction &MF, bool isVarArg,
644                         const SmallVectorImpl<ISD::OutputArg> &Outs,
645                         LLVMContext &Context) const override;
646 
647     SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
648                         const SmallVectorImpl<ISD::OutputArg> &Outs,
649                         const SmallVectorImpl<SDValue> &OutVals,
650                         const SDLoc &dl, SelectionDAG &DAG) const override;
651 
652     bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const override;
653 
654     bool mayBeEmittedAsTailCall(CallInst *CI) const override;
655 
656     SDValue getCMOV(const SDLoc &dl, EVT VT, SDValue FalseVal, SDValue TrueVal,
657                     SDValue ARMcc, SDValue CCR, SDValue Cmp,
658                     SelectionDAG &DAG) const;
659     SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
660                       SDValue &ARMcc, SelectionDAG &DAG, const SDLoc &dl) const;
661     SDValue getVFPCmp(SDValue LHS, SDValue RHS, SelectionDAG &DAG,
662                       const SDLoc &dl) const;
663     SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
664 
665     SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
666 
667     void SetupEntryBlockForSjLj(MachineInstr &MI, MachineBasicBlock *MBB,
668                                 MachineBasicBlock *DispatchBB, int FI) const;
669 
670     void EmitSjLjDispatchBlock(MachineInstr &MI, MachineBasicBlock *MBB) const;
671 
672     bool RemapAddSubWithFlags(MachineInstr &MI, MachineBasicBlock *BB) const;
673 
674     MachineBasicBlock *EmitStructByval(MachineInstr &MI,
675                                        MachineBasicBlock *MBB) const;
676 
677     MachineBasicBlock *EmitLowered__chkstk(MachineInstr &MI,
678                                            MachineBasicBlock *MBB) const;
679     MachineBasicBlock *EmitLowered__dbzchk(MachineInstr &MI,
680                                            MachineBasicBlock *MBB) const;
681   };
682 
683   enum NEONModImmType {
684     VMOVModImm,
685     VMVNModImm,
686     OtherModImm
687   };
688 
689   namespace ARM {
690     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
691                              const TargetLibraryInfo *libInfo);
692   }
693 }
694 
695 #endif  // ARMISELLOWERING_H
696