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
24namespace 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
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
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
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.
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
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
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.
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
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