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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 ARMISELLOWERING_H
16 #define 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 {
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       tCALL,        // Thumb function call.
47       BRCOND,       // Conditional branch.
48       BR_JT,        // Jumptable branch.
49       BR2_JT,       // Jumptable branch (2 level - jumptable entry is a jump).
50       RET_FLAG,     // Return with a flag operand.
51       INTRET_FLAG,  // Interrupt return with an LR-offset and a flag operand.
52 
53       PIC_ADD,      // Add with a PC operand and a PIC label.
54 
55       CMP,          // ARM compare instructions.
56       CMN,          // ARM CMN instructions.
57       CMPZ,         // ARM compare that sets only Z flag.
58       CMPFP,        // ARM VFP compare instruction, sets FPSCR.
59       CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
60       FMSTAT,       // ARM fmstat instruction.
61 
62       CMOV,         // ARM conditional move instructions.
63 
64       BCC_i64,
65 
66       RBIT,         // ARM bitreverse instruction
67 
68       FTOSI,        // FP to sint within a FP register.
69       FTOUI,        // FP to uint within a FP register.
70       SITOF,        // sint to FP within a FP register.
71       UITOF,        // uint to FP within a FP register.
72 
73       SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
74       SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
75       RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
76 
77       ADDC,         // Add with carry
78       ADDE,         // Add using carry
79       SUBC,         // Sub with carry
80       SUBE,         // Sub using carry
81 
82       VMOVRRD,      // double to two gprs.
83       VMOVDRR,      // Two gprs to double.
84 
85       EH_SJLJ_SETJMP,         // SjLj exception handling setjmp.
86       EH_SJLJ_LONGJMP,        // SjLj exception handling longjmp.
87 
88       TC_RETURN,    // Tail call return pseudo.
89 
90       THREAD_POINTER,
91 
92       DYN_ALLOC,    // Dynamic allocation on the stack.
93 
94       MEMBARRIER_MCR, // Memory barrier (MCR)
95 
96       PRELOAD,      // Preload
97 
98       WIN__CHKSTK,  // Windows' __chkstk call to do stack probing.
99 
100       VCEQ,         // Vector compare equal.
101       VCEQZ,        // Vector compare equal to zero.
102       VCGE,         // Vector compare greater than or equal.
103       VCGEZ,        // Vector compare greater than or equal to zero.
104       VCLEZ,        // Vector compare less than or equal to zero.
105       VCGEU,        // Vector compare unsigned greater than or equal.
106       VCGT,         // Vector compare greater than.
107       VCGTZ,        // Vector compare greater than zero.
108       VCLTZ,        // Vector compare less than zero.
109       VCGTU,        // Vector compare unsigned greater than.
110       VTST,         // Vector test bits.
111 
112       // Vector shift by immediate:
113       VSHL,         // ...left
114       VSHRs,        // ...right (signed)
115       VSHRu,        // ...right (unsigned)
116 
117       // Vector rounding shift by immediate:
118       VRSHRs,       // ...right (signed)
119       VRSHRu,       // ...right (unsigned)
120       VRSHRN,       // ...right narrow
121 
122       // Vector saturating shift by immediate:
123       VQSHLs,       // ...left (signed)
124       VQSHLu,       // ...left (unsigned)
125       VQSHLsu,      // ...left (signed to unsigned)
126       VQSHRNs,      // ...right narrow (signed)
127       VQSHRNu,      // ...right narrow (unsigned)
128       VQSHRNsu,     // ...right narrow (signed to unsigned)
129 
130       // Vector saturating rounding shift by immediate:
131       VQRSHRNs,     // ...right narrow (signed)
132       VQRSHRNu,     // ...right narrow (unsigned)
133       VQRSHRNsu,    // ...right narrow (signed to unsigned)
134 
135       // Vector shift and insert:
136       VSLI,         // ...left
137       VSRI,         // ...right
138 
139       // Vector get lane (VMOV scalar to ARM core register)
140       // (These are used for 8- and 16-bit element types only.)
141       VGETLANEu,    // zero-extend vector extract element
142       VGETLANEs,    // sign-extend vector extract element
143 
144       // Vector move immediate and move negated immediate:
145       VMOVIMM,
146       VMVNIMM,
147 
148       // Vector move f32 immediate:
149       VMOVFPIMM,
150 
151       // Vector duplicate:
152       VDUP,
153       VDUPLANE,
154 
155       // Vector shuffles:
156       VEXT,         // extract
157       VREV64,       // reverse elements within 64-bit doublewords
158       VREV32,       // reverse elements within 32-bit words
159       VREV16,       // reverse elements within 16-bit halfwords
160       VZIP,         // zip (interleave)
161       VUZP,         // unzip (deinterleave)
162       VTRN,         // transpose
163       VTBL1,        // 1-register shuffle with mask
164       VTBL2,        // 2-register shuffle with mask
165 
166       // Vector multiply long:
167       VMULLs,       // ...signed
168       VMULLu,       // ...unsigned
169 
170       UMLAL,        // 64bit Unsigned Accumulate Multiply
171       SMLAL,        // 64bit Signed Accumulate Multiply
172 
173       // Operands of the standard BUILD_VECTOR node are not legalized, which
174       // is fine if BUILD_VECTORs are always lowered to shuffles or other
175       // operations, but for ARM some BUILD_VECTORs are legal as-is and their
176       // operands need to be legalized.  Define an ARM-specific version of
177       // BUILD_VECTOR for this purpose.
178       BUILD_VECTOR,
179 
180       // Floating-point max and min:
181       FMAX,
182       FMIN,
183       VMAXNM,
184       VMINNM,
185 
186       // Bit-field insert
187       BFI,
188 
189       // Vector OR with immediate
190       VORRIMM,
191       // Vector AND with NOT of immediate
192       VBICIMM,
193 
194       // Vector bitwise select
195       VBSL,
196 
197       // Vector load N-element structure to all lanes:
198       VLD2DUP = ISD::FIRST_TARGET_MEMORY_OPCODE,
199       VLD3DUP,
200       VLD4DUP,
201 
202       // NEON loads with post-increment base updates:
203       VLD1_UPD,
204       VLD2_UPD,
205       VLD3_UPD,
206       VLD4_UPD,
207       VLD2LN_UPD,
208       VLD3LN_UPD,
209       VLD4LN_UPD,
210       VLD2DUP_UPD,
211       VLD3DUP_UPD,
212       VLD4DUP_UPD,
213 
214       // NEON stores with post-increment base updates:
215       VST1_UPD,
216       VST2_UPD,
217       VST3_UPD,
218       VST4_UPD,
219       VST2LN_UPD,
220       VST3LN_UPD,
221       VST4LN_UPD
222     };
223   }
224 
225   /// Define some predicates that are used for node matching.
226   namespace ARM {
227     bool isBitFieldInvertedMask(unsigned v);
228   }
229 
230   //===--------------------------------------------------------------------===//
231   //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
232 
233   class ARMTargetLowering : public TargetLowering {
234   public:
235     explicit ARMTargetLowering(TargetMachine &TM);
236 
237     unsigned getJumpTableEncoding() const override;
238 
239     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
240 
241     /// ReplaceNodeResults - Replace the results of node with an illegal result
242     /// type with new values built out of custom code.
243     ///
244     void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
245                             SelectionDAG &DAG) const override;
246 
247     const char *getTargetNodeName(unsigned Opcode) const override;
248 
isSelectSupported(SelectSupportKind Kind)249     bool isSelectSupported(SelectSupportKind Kind) const override {
250       // ARM does not support scalar condition selects on vectors.
251       return (Kind != ScalarCondVectorVal);
252     }
253 
254     /// getSetCCResultType - Return the value type to use for ISD::SETCC.
255     EVT getSetCCResultType(LLVMContext &Context, EVT VT) const override;
256 
257     MachineBasicBlock *
258       EmitInstrWithCustomInserter(MachineInstr *MI,
259                                   MachineBasicBlock *MBB) const override;
260 
261     void AdjustInstrPostInstrSelection(MachineInstr *MI,
262                                        SDNode *Node) const override;
263 
264     SDValue PerformCMOVCombine(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     /// allowsUnalignedMemoryAccesses - 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 allowsUnalignedMemoryAccesses(EVT VT, unsigned AddrSpace,
273                                        bool *Fast) const override;
274 
275     EVT getOptimalMemOpType(uint64_t Size,
276                             unsigned DstAlign, unsigned SrcAlign,
277                             bool IsMemset, bool ZeroMemset,
278                             bool MemcpyStrSrc,
279                             MachineFunction &MF) const override;
280 
281     using TargetLowering::isZExtFree;
282     bool isZExtFree(SDValue Val, EVT VT2) const override;
283 
284     bool allowTruncateForTailCall(Type *Ty1, Type *Ty2) const override;
285 
286 
287     /// isLegalAddressingMode - Return true if the addressing mode represented
288     /// by AM is legal for this target, for a load/store of the specified type.
289     bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const override;
290     bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
291 
292     /// isLegalICmpImmediate - Return true if the specified immediate is legal
293     /// icmp immediate, that is the target has icmp instructions which can
294     /// compare a register against the immediate without having to materialize
295     /// the immediate into a register.
296     bool isLegalICmpImmediate(int64_t Imm) const override;
297 
298     /// isLegalAddImmediate - Return true if the specified immediate is legal
299     /// add immediate, that is the target has add instructions which can
300     /// add a register and the immediate without having to materialize
301     /// the immediate into a register.
302     bool isLegalAddImmediate(int64_t Imm) const override;
303 
304     /// getPreIndexedAddressParts - returns true by value, base pointer and
305     /// offset pointer and addressing mode by reference if the node's address
306     /// can be legally represented as pre-indexed load / store address.
307     bool getPreIndexedAddressParts(SDNode *N, SDValue &Base, SDValue &Offset,
308                                    ISD::MemIndexedMode &AM,
309                                    SelectionDAG &DAG) const override;
310 
311     /// getPostIndexedAddressParts - returns true by value, base pointer and
312     /// offset pointer and addressing mode by reference if this node can be
313     /// combined with a load / store to form a post-indexed load / store.
314     bool getPostIndexedAddressParts(SDNode *N, SDNode *Op, SDValue &Base,
315                                     SDValue &Offset, ISD::MemIndexedMode &AM,
316                                     SelectionDAG &DAG) const override;
317 
318     void computeKnownBitsForTargetNode(const SDValue Op, APInt &KnownZero,
319                                        APInt &KnownOne,
320                                        const SelectionDAG &DAG,
321                                        unsigned Depth) const override;
322 
323 
324     bool ExpandInlineAsm(CallInst *CI) const override;
325 
326     ConstraintType
327       getConstraintType(const std::string &Constraint) const override;
328 
329     /// Examine constraint string and operand type and determine a weight value.
330     /// The operand object must already have been set up with the operand type.
331     ConstraintWeight getSingleConstraintMatchWeight(
332       AsmOperandInfo &info, const char *constraint) const override;
333 
334     std::pair<unsigned, const TargetRegisterClass*>
335       getRegForInlineAsmConstraint(const std::string &Constraint,
336                                    MVT VT) const override;
337 
338     /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
339     /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
340     /// true it means one of the asm constraint of the inline asm instruction
341     /// being processed is 'm'.
342     void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
343                                       std::vector<SDValue> &Ops,
344                                       SelectionDAG &DAG) const override;
345 
getSubtarget()346     const ARMSubtarget* getSubtarget() const {
347       return Subtarget;
348     }
349 
350     /// getRegClassFor - Return the register class that should be used for the
351     /// specified value type.
352     const TargetRegisterClass *getRegClassFor(MVT VT) const override;
353 
354     /// getMaximalGlobalOffset - Returns the maximal possible offset which can
355     /// be used for loads / stores from the global.
356     unsigned getMaximalGlobalOffset() const override;
357 
358     /// Returns true if a cast between SrcAS and DestAS is a noop.
isNoopAddrSpaceCast(unsigned SrcAS,unsigned DestAS)359     bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override {
360       // Addrspacecasts are always noops.
361       return true;
362     }
363 
364     /// createFastISel - This method returns a target specific FastISel object,
365     /// or null if the target does not support "fast" ISel.
366     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
367                              const TargetLibraryInfo *libInfo) const override;
368 
369     Sched::Preference getSchedulingPreference(SDNode *N) const override;
370 
371     bool
372     isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const override;
373     bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
374 
375     /// isFPImmLegal - Returns true if the target can instruction select the
376     /// specified FP immediate natively. If false, the legalizer will
377     /// materialize the FP immediate as a load from a constant pool.
378     bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
379 
380     bool getTgtMemIntrinsic(IntrinsicInfo &Info,
381                             const CallInst &I,
382                             unsigned Intrinsic) const override;
383 
384     /// \brief Returns true if it is beneficial to convert a load of a constant
385     /// to just the constant itself.
386     bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
387                                            Type *Ty) const override;
388 
389     /// \brief Returns true if an argument of type Ty needs to be passed in a
390     /// contiguous block of registers in calling convention CallConv.
391     bool functionArgumentNeedsConsecutiveRegisters(
392         Type *Ty, CallingConv::ID CallConv, bool isVarArg) const override;
393 
394     Value *emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
395                           AtomicOrdering Ord) const override;
396     Value *emitStoreConditional(IRBuilder<> &Builder, Value *Val,
397                                 Value *Addr, AtomicOrdering Ord) const override;
398 
399     bool shouldExpandAtomicInIR(Instruction *Inst) const override;
400 
401   protected:
402     std::pair<const TargetRegisterClass*, uint8_t>
403     findRepresentativeClass(MVT VT) const override;
404 
405   private:
406     /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
407     /// make the right decision when generating code for different targets.
408     const ARMSubtarget *Subtarget;
409 
410     const TargetRegisterInfo *RegInfo;
411 
412     const InstrItineraryData *Itins;
413 
414     /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
415     ///
416     unsigned ARMPCLabelIndex;
417 
418     void addTypeForNEON(MVT VT, MVT PromotedLdStVT, MVT PromotedBitwiseVT);
419     void addDRTypeForNEON(MVT VT);
420     void addQRTypeForNEON(MVT VT);
421     std::pair<SDValue, SDValue> getARMXALUOOp(SDValue Op, SelectionDAG &DAG, SDValue &ARMcc) const;
422 
423     typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
424     void PassF64ArgInRegs(SDLoc dl, SelectionDAG &DAG,
425                           SDValue Chain, SDValue &Arg,
426                           RegsToPassVector &RegsToPass,
427                           CCValAssign &VA, CCValAssign &NextVA,
428                           SDValue &StackPtr,
429                           SmallVectorImpl<SDValue> &MemOpChains,
430                           ISD::ArgFlagsTy Flags) const;
431     SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
432                                  SDValue &Root, SelectionDAG &DAG,
433                                  SDLoc dl) const;
434 
435     CallingConv::ID getEffectiveCallingConv(CallingConv::ID CC,
436                                             bool isVarArg) const;
437     CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
438                                   bool isVarArg) const;
439     SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
440                              SDLoc dl, SelectionDAG &DAG,
441                              const CCValAssign &VA,
442                              ISD::ArgFlagsTy Flags) const;
443     SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
444     SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
445     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
446                                     const ARMSubtarget *Subtarget) const;
447     SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
448     SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
449     SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
450     SDValue LowerGlobalAddressWindows(SDValue Op, SelectionDAG &DAG) const;
451     SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
452     SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
453                                             SelectionDAG &DAG) const;
454     SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
455                                  SelectionDAG &DAG,
456                                  TLSModel::Model model) const;
457     SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
458     SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
459     SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) const;
460     SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
461     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
462     SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
463     SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
464     SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
465     SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
466     SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
467     SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
468     SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
469     SDValue LowerConstantFP(SDValue Op, SelectionDAG &DAG,
470                             const ARMSubtarget *ST) const;
471     SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
472                               const ARMSubtarget *ST) const;
473     SDValue LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const;
474     SDValue LowerDivRem(SDValue Op, SelectionDAG &DAG) const;
475     SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
476 
477     unsigned getRegisterByName(const char* RegName, EVT VT) const override;
478 
479     /// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
480     /// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
481     /// expanded to FMAs when this method returns true, otherwise fmuladd is
482     /// expanded to fmul + fadd.
483     ///
484     /// ARM supports both fused and unfused multiply-add operations; we already
485     /// lower a pair of fmul and fadd to the latter so it's not clear that there
486     /// would be a gain or that the gain would be worthwhile enough to risk
487     /// correctness bugs.
isFMAFasterThanFMulAndFAdd(EVT VT)488     bool isFMAFasterThanFMulAndFAdd(EVT VT) const override { return false; }
489 
490     SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
491 
492     SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
493                             CallingConv::ID CallConv, bool isVarArg,
494                             const SmallVectorImpl<ISD::InputArg> &Ins,
495                             SDLoc dl, SelectionDAG &DAG,
496                             SmallVectorImpl<SDValue> &InVals,
497                             bool isThisReturn, SDValue ThisVal) const;
498 
499     SDValue
500       LowerFormalArguments(SDValue Chain,
501                            CallingConv::ID CallConv, bool isVarArg,
502                            const SmallVectorImpl<ISD::InputArg> &Ins,
503                            SDLoc dl, SelectionDAG &DAG,
504                            SmallVectorImpl<SDValue> &InVals) const override;
505 
506     int StoreByValRegs(CCState &CCInfo, SelectionDAG &DAG,
507                        SDLoc dl, SDValue &Chain,
508                        const Value *OrigArg,
509                        unsigned InRegsParamRecordIdx,
510                        unsigned OffsetFromOrigArg,
511                        unsigned ArgOffset,
512                        unsigned ArgSize,
513                        bool ForceMutable,
514                        unsigned ByValStoreOffset,
515                        unsigned TotalArgRegsSaveSize) const;
516 
517     void VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
518                               SDLoc dl, SDValue &Chain,
519                               unsigned ArgOffset,
520                               unsigned TotalArgRegsSaveSize,
521                               bool ForceMutable = false) const;
522 
523     void computeRegArea(CCState &CCInfo, MachineFunction &MF,
524                         unsigned InRegsParamRecordIdx,
525                         unsigned ArgSize,
526                         unsigned &ArgRegsSize,
527                         unsigned &ArgRegsSaveSize) const;
528 
529     SDValue
530       LowerCall(TargetLowering::CallLoweringInfo &CLI,
531                 SmallVectorImpl<SDValue> &InVals) const override;
532 
533     /// HandleByVal - Target-specific cleanup for ByVal support.
534     void HandleByVal(CCState *, unsigned &, unsigned) const override;
535 
536     /// IsEligibleForTailCallOptimization - Check whether the call is eligible
537     /// for tail call optimization. Targets which want to do tail call
538     /// optimization should implement this function.
539     bool IsEligibleForTailCallOptimization(SDValue Callee,
540                                            CallingConv::ID CalleeCC,
541                                            bool isVarArg,
542                                            bool isCalleeStructRet,
543                                            bool isCallerStructRet,
544                                     const SmallVectorImpl<ISD::OutputArg> &Outs,
545                                     const SmallVectorImpl<SDValue> &OutVals,
546                                     const SmallVectorImpl<ISD::InputArg> &Ins,
547                                            SelectionDAG& DAG) const;
548 
549     bool CanLowerReturn(CallingConv::ID CallConv,
550                         MachineFunction &MF, bool isVarArg,
551                         const SmallVectorImpl<ISD::OutputArg> &Outs,
552                         LLVMContext &Context) const override;
553 
554     SDValue
555       LowerReturn(SDValue Chain,
556                   CallingConv::ID CallConv, bool isVarArg,
557                   const SmallVectorImpl<ISD::OutputArg> &Outs,
558                   const SmallVectorImpl<SDValue> &OutVals,
559                   SDLoc dl, SelectionDAG &DAG) const override;
560 
561     bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const override;
562 
563     bool mayBeEmittedAsTailCall(CallInst *CI) const override;
564 
565     SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
566                       SDValue &ARMcc, SelectionDAG &DAG, SDLoc dl) const;
567     SDValue getVFPCmp(SDValue LHS, SDValue RHS,
568                       SelectionDAG &DAG, SDLoc dl) const;
569     SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
570 
571     SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
572 
573     void SetupEntryBlockForSjLj(MachineInstr *MI,
574                                 MachineBasicBlock *MBB,
575                                 MachineBasicBlock *DispatchBB, int FI) const;
576 
577     MachineBasicBlock *EmitSjLjDispatchBlock(MachineInstr *MI,
578                                              MachineBasicBlock *MBB) const;
579 
580     bool RemapAddSubWithFlags(MachineInstr *MI, MachineBasicBlock *BB) const;
581 
582     MachineBasicBlock *EmitStructByval(MachineInstr *MI,
583                                        MachineBasicBlock *MBB) const;
584 
585     MachineBasicBlock *EmitLowered__chkstk(MachineInstr *MI,
586                                            MachineBasicBlock *MBB) const;
587   };
588 
589   enum NEONModImmType {
590     VMOVModImm,
591     VMVNModImm,
592     OtherModImm
593   };
594 
595   namespace ARM {
596     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
597                              const TargetLibraryInfo *libInfo);
598   }
599 }
600 
601 #endif  // ARMISELLOWERING_H
602