ARMISelLowering.h revision 763a75dbf719242e7f99c6447d20b9bffb75dfa2
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 "ARM.h"
19#include "ARMSubtarget.h"
20#include "llvm/Target/TargetLowering.h"
21#include "llvm/Target/TargetRegisterInfo.h"
22#include "llvm/CodeGen/FastISel.h"
23#include "llvm/CodeGen/SelectionDAG.h"
24#include "llvm/CodeGen/CallingConvLower.h"
25#include <vector>
26
27namespace llvm {
28  class ARMConstantPoolValue;
29
30  namespace ARMISD {
31    // ARM Specific DAG Nodes
32    enum NodeType {
33      // Start the numbering where the builtin ops and target ops leave off.
34      FIRST_NUMBER = ISD::BUILTIN_OP_END,
35
36      Wrapper,      // Wrapper - A wrapper node for TargetConstantPool,
37                    // TargetExternalSymbol, and TargetGlobalAddress.
38      WrapperDYN,   // WrapperDYN - A wrapper node for TargetGlobalAddress in
39                    // DYN mode.
40      WrapperPIC,   // WrapperPIC - A wrapper node for TargetGlobalAddress in
41                    // PIC mode.
42      WrapperJT,    // WrapperJT - A wrapper node for TargetJumpTable
43
44      // Add pseudo op to model memcpy for struct byval.
45      COPY_STRUCT_BYVAL,
46
47      CALL,         // Function call.
48      CALL_PRED,    // Function call that's predicable.
49      CALL_NOLINK,  // Function call with branch not branch-and-link.
50      tCALL,        // Thumb function call.
51      BRCOND,       // Conditional branch.
52      BR_JT,        // Jumptable branch.
53      BR2_JT,       // Jumptable branch (2 level - jumptable entry is a jump).
54      RET_FLAG,     // Return with a flag operand.
55
56      PIC_ADD,      // Add with a PC operand and a PIC label.
57
58      CMP,          // ARM compare instructions.
59      CMPZ,         // ARM compare that sets only Z flag.
60      CMPFP,        // ARM VFP compare instruction, sets FPSCR.
61      CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
62      FMSTAT,       // ARM fmstat instruction.
63
64      CMOV,         // ARM conditional move instructions.
65      CAND,         // ARM conditional and instructions.
66      COR,          // ARM conditional or instructions.
67      CXOR,         // ARM conditional xor instructions.
68
69      BCC_i64,
70
71      RBIT,         // ARM bitreverse instruction
72
73      FTOSI,        // FP to sint within a FP register.
74      FTOUI,        // FP to uint within a FP register.
75      SITOF,        // sint to FP within a FP register.
76      UITOF,        // uint to FP within a FP register.
77
78      SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
79      SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
80      RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
81
82      ADDC,         // Add with carry
83      ADDE,         // Add using carry
84      SUBC,         // Sub with carry
85      SUBE,         // Sub using carry
86
87      VMOVRRD,      // double to two gprs.
88      VMOVDRR,      // Two gprs to double.
89
90      EH_SJLJ_SETJMP,         // SjLj exception handling setjmp.
91      EH_SJLJ_LONGJMP,        // SjLj exception handling longjmp.
92
93      TC_RETURN,    // Tail call return pseudo.
94
95      THREAD_POINTER,
96
97      DYN_ALLOC,    // Dynamic allocation on the stack.
98
99      MEMBARRIER,   // Memory barrier (DMB)
100      MEMBARRIER_MCR, // Memory barrier (MCR)
101
102      PRELOAD,      // Preload
103
104      VCEQ,         // Vector compare equal.
105      VCEQZ,        // Vector compare equal to zero.
106      VCGE,         // Vector compare greater than or equal.
107      VCGEZ,        // Vector compare greater than or equal to zero.
108      VCLEZ,        // Vector compare less than or equal to zero.
109      VCGEU,        // Vector compare unsigned greater than or equal.
110      VCGT,         // Vector compare greater than.
111      VCGTZ,        // Vector compare greater than zero.
112      VCLTZ,        // Vector compare less than zero.
113      VCGTU,        // Vector compare unsigned greater than.
114      VTST,         // Vector test bits.
115
116      // Vector shift by immediate:
117      VSHL,         // ...left
118      VSHRs,        // ...right (signed)
119      VSHRu,        // ...right (unsigned)
120      VSHLLs,       // ...left long (signed)
121      VSHLLu,       // ...left long (unsigned)
122      VSHLLi,       // ...left long (with maximum shift count)
123      VSHRN,        // ...right narrow
124
125      // Vector rounding shift by immediate:
126      VRSHRs,       // ...right (signed)
127      VRSHRu,       // ...right (unsigned)
128      VRSHRN,       // ...right narrow
129
130      // Vector saturating shift by immediate:
131      VQSHLs,       // ...left (signed)
132      VQSHLu,       // ...left (unsigned)
133      VQSHLsu,      // ...left (signed to unsigned)
134      VQSHRNs,      // ...right narrow (signed)
135      VQSHRNu,      // ...right narrow (unsigned)
136      VQSHRNsu,     // ...right narrow (signed to unsigned)
137
138      // Vector saturating rounding shift by immediate:
139      VQRSHRNs,     // ...right narrow (signed)
140      VQRSHRNu,     // ...right narrow (unsigned)
141      VQRSHRNsu,    // ...right narrow (signed to unsigned)
142
143      // Vector shift and insert:
144      VSLI,         // ...left
145      VSRI,         // ...right
146
147      // Vector get lane (VMOV scalar to ARM core register)
148      // (These are used for 8- and 16-bit element types only.)
149      VGETLANEu,    // zero-extend vector extract element
150      VGETLANEs,    // sign-extend vector extract element
151
152      // Vector move immediate and move negated immediate:
153      VMOVIMM,
154      VMVNIMM,
155
156      // Vector move f32 immediate:
157      VMOVFPIMM,
158
159      // Vector duplicate:
160      VDUP,
161      VDUPLANE,
162
163      // Vector shuffles:
164      VEXT,         // extract
165      VREV64,       // reverse elements within 64-bit doublewords
166      VREV32,       // reverse elements within 32-bit words
167      VREV16,       // reverse elements within 16-bit halfwords
168      VZIP,         // zip (interleave)
169      VUZP,         // unzip (deinterleave)
170      VTRN,         // transpose
171      VTBL1,        // 1-register shuffle with mask
172      VTBL2,        // 2-register shuffle with mask
173
174      // Vector multiply long:
175      VMULLs,       // ...signed
176      VMULLu,       // ...unsigned
177
178      // Operands of the standard BUILD_VECTOR node are not legalized, which
179      // is fine if BUILD_VECTORs are always lowered to shuffles or other
180      // operations, but for ARM some BUILD_VECTORs are legal as-is and their
181      // operands need to be legalized.  Define an ARM-specific version of
182      // BUILD_VECTOR for this purpose.
183      BUILD_VECTOR,
184
185      // Floating-point max and min:
186      FMAX,
187      FMIN,
188
189      // Bit-field insert
190      BFI,
191
192      // Vector OR with immediate
193      VORRIMM,
194      // Vector AND with NOT of immediate
195      VBICIMM,
196
197      // Vector bitwise select
198      VBSL,
199
200      // Vector load N-element structure to all lanes:
201      VLD2DUP = ISD::FIRST_TARGET_MEMORY_OPCODE,
202      VLD3DUP,
203      VLD4DUP,
204
205      // NEON loads with post-increment base updates:
206      VLD1_UPD,
207      VLD2_UPD,
208      VLD3_UPD,
209      VLD4_UPD,
210      VLD2LN_UPD,
211      VLD3LN_UPD,
212      VLD4LN_UPD,
213      VLD2DUP_UPD,
214      VLD3DUP_UPD,
215      VLD4DUP_UPD,
216
217      // NEON stores with post-increment base updates:
218      VST1_UPD,
219      VST2_UPD,
220      VST3_UPD,
221      VST4_UPD,
222      VST2LN_UPD,
223      VST3LN_UPD,
224      VST4LN_UPD,
225
226      // 64-bit atomic ops (value split into two registers)
227      ATOMADD64_DAG,
228      ATOMSUB64_DAG,
229      ATOMOR64_DAG,
230      ATOMXOR64_DAG,
231      ATOMAND64_DAG,
232      ATOMNAND64_DAG,
233      ATOMSWAP64_DAG,
234      ATOMCMPXCHG64_DAG
235    };
236  }
237
238  /// Define some predicates that are used for node matching.
239  namespace ARM {
240    bool isBitFieldInvertedMask(unsigned v);
241  }
242
243  //===--------------------------------------------------------------------===//
244  //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
245
246  class ARMTargetLowering : public TargetLowering {
247  public:
248    explicit ARMTargetLowering(TargetMachine &TM);
249
250    virtual unsigned getJumpTableEncoding(void) const;
251
252    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
253
254    /// ReplaceNodeResults - Replace the results of node with an illegal result
255    /// type with new values built out of custom code.
256    ///
257    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
258                                    SelectionDAG &DAG) const;
259
260    virtual const char *getTargetNodeName(unsigned Opcode) const;
261
262    /// getSetCCResultType - Return the value type to use for ISD::SETCC.
263    virtual EVT getSetCCResultType(EVT VT) const;
264
265    virtual MachineBasicBlock *
266      EmitInstrWithCustomInserter(MachineInstr *MI,
267                                  MachineBasicBlock *MBB) const;
268
269    virtual void
270    AdjustInstrPostInstrSelection(MachineInstr *MI, SDNode *Node) const;
271
272    SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const;
273    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
274
275    bool isDesirableToTransformToIntegerOp(unsigned Opc, EVT VT) const;
276
277    /// allowsUnalignedMemoryAccesses - Returns true if the target allows
278    /// unaligned memory accesses. of the specified type.
279    virtual bool allowsUnalignedMemoryAccesses(EVT VT) const;
280
281    virtual EVT getOptimalMemOpType(uint64_t Size,
282                                    unsigned DstAlign, unsigned SrcAlign,
283                                    bool IsZeroVal,
284                                    bool MemcpyStrSrc,
285                                    MachineFunction &MF) const;
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    virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty)const;
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    virtual bool isLegalICmpImmediate(int64_t Imm) const;
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    virtual bool isLegalAddImmediate(int64_t Imm) const;
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    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
308                                           SDValue &Offset,
309                                           ISD::MemIndexedMode &AM,
310                                           SelectionDAG &DAG) const;
311
312    /// getPostIndexedAddressParts - returns true by value, base pointer and
313    /// offset pointer and addressing mode by reference if this node can be
314    /// combined with a load / store to form a post-indexed load / store.
315    virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
316                                            SDValue &Base, SDValue &Offset,
317                                            ISD::MemIndexedMode &AM,
318                                            SelectionDAG &DAG) const;
319
320    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
321                                                APInt &KnownZero,
322                                                APInt &KnownOne,
323                                                const SelectionDAG &DAG,
324                                                unsigned Depth) const;
325
326
327    virtual bool ExpandInlineAsm(CallInst *CI) const;
328
329    ConstraintType getConstraintType(const std::string &Constraint) const;
330
331    /// Examine constraint string and operand type and determine a weight value.
332    /// The operand object must already have been set up with the operand type.
333    ConstraintWeight getSingleConstraintMatchWeight(
334      AsmOperandInfo &info, const char *constraint) const;
335
336    std::pair<unsigned, const TargetRegisterClass*>
337      getRegForInlineAsmConstraint(const std::string &Constraint,
338                                   EVT VT) const;
339
340    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
341    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
342    /// true it means one of the asm constraint of the inline asm instruction
343    /// being processed is 'm'.
344    virtual void LowerAsmOperandForConstraint(SDValue Op,
345                                              std::string &Constraint,
346                                              std::vector<SDValue> &Ops,
347                                              SelectionDAG &DAG) const;
348
349    const ARMSubtarget* getSubtarget() const {
350      return Subtarget;
351    }
352
353    /// getRegClassFor - Return the register class that should be used for the
354    /// specified value type.
355    virtual const TargetRegisterClass *getRegClassFor(EVT VT) const;
356
357    /// getMaximalGlobalOffset - Returns the maximal possible offset which can
358    /// be used for loads / stores from the global.
359    virtual unsigned getMaximalGlobalOffset() const;
360
361    /// createFastISel - This method returns a target specific FastISel object,
362    /// or null if the target does not support "fast" ISel.
363    virtual FastISel *createFastISel(FunctionLoweringInfo &funcInfo) const;
364
365    Sched::Preference getSchedulingPreference(SDNode *N) const;
366
367    bool isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const;
368    bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
369
370    /// isFPImmLegal - Returns true if the target can instruction select the
371    /// specified FP immediate natively. If false, the legalizer will
372    /// materialize the FP immediate as a load from a constant pool.
373    virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const;
374
375    virtual bool getTgtMemIntrinsic(IntrinsicInfo &Info,
376                                    const CallInst &I,
377                                    unsigned Intrinsic) const;
378  protected:
379    std::pair<const TargetRegisterClass*, uint8_t>
380    findRepresentativeClass(EVT VT) const;
381
382  private:
383    /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
384    /// make the right decision when generating code for different targets.
385    const ARMSubtarget *Subtarget;
386
387    const TargetRegisterInfo *RegInfo;
388
389    const InstrItineraryData *Itins;
390
391    /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
392    ///
393    unsigned ARMPCLabelIndex;
394
395    void addTypeForNEON(EVT VT, EVT PromotedLdStVT, EVT PromotedBitwiseVT);
396    void addDRTypeForNEON(EVT VT);
397    void addQRTypeForNEON(EVT VT);
398
399    typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
400    void PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
401                          SDValue Chain, SDValue &Arg,
402                          RegsToPassVector &RegsToPass,
403                          CCValAssign &VA, CCValAssign &NextVA,
404                          SDValue &StackPtr,
405                          SmallVector<SDValue, 8> &MemOpChains,
406                          ISD::ArgFlagsTy Flags) const;
407    SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
408                                 SDValue &Root, SelectionDAG &DAG,
409                                 DebugLoc dl) const;
410
411    CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
412                                  bool isVarArg) const;
413    SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
414                             DebugLoc dl, SelectionDAG &DAG,
415                             const CCValAssign &VA,
416                             ISD::ArgFlagsTy Flags) const;
417    SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
418    SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
419    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
420                                    const ARMSubtarget *Subtarget) const;
421    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
422    SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
423    SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
424    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
425    SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
426                                            SelectionDAG &DAG) const;
427    SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
428                                 SelectionDAG &DAG,
429                                 TLSModel::Model model) const;
430    SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
431    SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
432    SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
433    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
434    SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
435    SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
436    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
437    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
438    SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
439    SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
440    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
441    SDValue LowerConstantFP(SDValue Op, SelectionDAG &DAG,
442                            const ARMSubtarget *ST) const;
443    SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
444                              const ARMSubtarget *ST) const;
445
446    SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
447
448    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
449                            CallingConv::ID CallConv, bool isVarArg,
450                            const SmallVectorImpl<ISD::InputArg> &Ins,
451                            DebugLoc dl, SelectionDAG &DAG,
452                            SmallVectorImpl<SDValue> &InVals) const;
453
454    virtual SDValue
455      LowerFormalArguments(SDValue Chain,
456                           CallingConv::ID CallConv, bool isVarArg,
457                           const SmallVectorImpl<ISD::InputArg> &Ins,
458                           DebugLoc dl, SelectionDAG &DAG,
459                           SmallVectorImpl<SDValue> &InVals) const;
460
461    void VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
462                              DebugLoc dl, SDValue &Chain, unsigned ArgOffset)
463      const;
464
465    void computeRegArea(CCState &CCInfo, MachineFunction &MF,
466                        unsigned &VARegSize, unsigned &VARegSaveSize) const;
467
468    virtual SDValue
469      LowerCall(TargetLowering::CallLoweringInfo &CLI,
470                SmallVectorImpl<SDValue> &InVals) const;
471
472    /// HandleByVal - Target-specific cleanup for ByVal support.
473    virtual void HandleByVal(CCState *, unsigned &) const;
474
475    /// IsEligibleForTailCallOptimization - Check whether the call is eligible
476    /// for tail call optimization. Targets which want to do tail call
477    /// optimization should implement this function.
478    bool IsEligibleForTailCallOptimization(SDValue Callee,
479                                           CallingConv::ID CalleeCC,
480                                           bool isVarArg,
481                                           bool isCalleeStructRet,
482                                           bool isCallerStructRet,
483                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
484                                    const SmallVectorImpl<SDValue> &OutVals,
485                                    const SmallVectorImpl<ISD::InputArg> &Ins,
486                                           SelectionDAG& DAG) const;
487    virtual SDValue
488      LowerReturn(SDValue Chain,
489                  CallingConv::ID CallConv, bool isVarArg,
490                  const SmallVectorImpl<ISD::OutputArg> &Outs,
491                  const SmallVectorImpl<SDValue> &OutVals,
492                  DebugLoc dl, SelectionDAG &DAG) const;
493
494    virtual bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const;
495
496    virtual bool mayBeEmittedAsTailCall(CallInst *CI) const;
497
498    SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
499                      SDValue &ARMcc, SelectionDAG &DAG, DebugLoc dl) const;
500    SDValue getVFPCmp(SDValue LHS, SDValue RHS,
501                      SelectionDAG &DAG, DebugLoc dl) const;
502    SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
503
504    SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
505
506    MachineBasicBlock *EmitAtomicCmpSwap(MachineInstr *MI,
507                                         MachineBasicBlock *BB,
508                                         unsigned Size) const;
509    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
510                                        MachineBasicBlock *BB,
511                                        unsigned Size,
512                                        unsigned BinOpcode) const;
513    MachineBasicBlock *EmitAtomicBinary64(MachineInstr *MI,
514                                          MachineBasicBlock *BB,
515                                          unsigned Op1,
516                                          unsigned Op2,
517                                          bool NeedsCarry = false,
518                                          bool IsCmpxchg = false) const;
519    MachineBasicBlock * EmitAtomicBinaryMinMax(MachineInstr *MI,
520                                               MachineBasicBlock *BB,
521                                               unsigned Size,
522                                               bool signExtend,
523                                               ARMCC::CondCodes Cond) const;
524
525    void SetupEntryBlockForSjLj(MachineInstr *MI,
526                                MachineBasicBlock *MBB,
527                                MachineBasicBlock *DispatchBB, int FI) const;
528
529    MachineBasicBlock *EmitSjLjDispatchBlock(MachineInstr *MI,
530                                             MachineBasicBlock *MBB) const;
531
532    bool RemapAddSubWithFlags(MachineInstr *MI, MachineBasicBlock *BB) const;
533  };
534
535  enum NEONModImmType {
536    VMOVModImm,
537    VMVNModImm,
538    OtherModImm
539  };
540
541
542  namespace ARM {
543    FastISel *createFastISel(FunctionLoweringInfo &funcInfo);
544  }
545}
546
547#endif  // ARMISELLOWERING_H
548