ARMISelLowering.h revision 44d23825d61d530b8d562329ec8fc2d4f843bb8d
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 "ARMSubtarget.h"
19#include "llvm/Target/TargetLowering.h"
20#include "llvm/Target/TargetRegisterInfo.h"
21#include "llvm/CodeGen/FastISel.h"
22#include "llvm/CodeGen/SelectionDAG.h"
23#include "llvm/CodeGen/CallingConvLower.h"
24#include <vector>
25
26namespace llvm {
27  class ARMConstantPoolValue;
28
29  namespace ARMISD {
30    // ARM Specific DAG Nodes
31    enum NodeType {
32      // Start the numbering where the builtin ops and target ops leave off.
33      FIRST_NUMBER = ISD::BUILTIN_OP_END,
34
35      Wrapper,      // Wrapper - A wrapper node for TargetConstantPool,
36                    // TargetExternalSymbol, and TargetGlobalAddress.
37      WrapperDYN,   // WrapperDYN - A wrapper node for TargetGlobalAddress in
38                    // DYN mode.
39      WrapperPIC,   // WrapperPIC - A wrapper node for TargetGlobalAddress in
40                    // PIC mode.
41      WrapperJT,    // WrapperJT - A wrapper node for TargetJumpTable
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
52      PIC_ADD,      // Add with a PC operand and a PIC label.
53
54      CMP,          // ARM compare instructions.
55      CMPZ,         // ARM compare that sets only Z flag.
56      CMPFP,        // ARM VFP compare instruction, sets FPSCR.
57      CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
58      FMSTAT,       // ARM fmstat instruction.
59      CMOV,         // ARM conditional move instructions.
60
61      BCC_i64,
62
63      RBIT,         // ARM bitreverse instruction
64
65      FTOSI,        // FP to sint within a FP register.
66      FTOUI,        // FP to uint within a FP register.
67      SITOF,        // sint to FP within a FP register.
68      UITOF,        // uint to FP within a FP register.
69
70      SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
71      SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
72      RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
73
74      ADDC,         // Add with carry
75      ADDE,         // Add using carry
76      SUBC,         // Sub with carry
77      SUBE,         // Sub using carry
78
79      VMOVRRD,      // double to two gprs.
80      VMOVDRR,      // Two gprs to double.
81
82      EH_SJLJ_SETJMP,         // SjLj exception handling setjmp.
83      EH_SJLJ_LONGJMP,        // SjLj exception handling longjmp.
84
85      TC_RETURN,    // Tail call return pseudo.
86
87      THREAD_POINTER,
88
89      DYN_ALLOC,    // Dynamic allocation on the stack.
90
91      MEMBARRIER,   // Memory barrier (DMB)
92      MEMBARRIER_MCR, // Memory barrier (MCR)
93
94      PRELOAD,      // Preload
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      VSHLLs,       // ...left long (signed)
113      VSHLLu,       // ...left long (unsigned)
114      VSHLLi,       // ...left long (with maximum shift count)
115      VSHRN,        // ...right narrow
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      // 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      // Floating-point max and min:
178      FMAX,
179      FMIN,
180
181      // Bit-field insert
182      BFI,
183
184      // Vector OR with immediate
185      VORRIMM,
186      // Vector AND with NOT of immediate
187      VBICIMM,
188
189      // Vector bitwise select
190      VBSL,
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      // 64-bit atomic ops (value split into two registers)
219      ATOMADD64_DAG,
220      ATOMSUB64_DAG,
221      ATOMOR64_DAG,
222      ATOMXOR64_DAG,
223      ATOMAND64_DAG,
224      ATOMNAND64_DAG,
225      ATOMSWAP64_DAG,
226      ATOMCMPXCHG64_DAG
227    };
228  }
229
230  /// Define some predicates that are used for node matching.
231  namespace ARM {
232    bool isBitFieldInvertedMask(unsigned v);
233  }
234
235  //===--------------------------------------------------------------------===//
236  //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
237
238  class ARMTargetLowering : public TargetLowering {
239  public:
240    explicit ARMTargetLowering(TargetMachine &TM);
241
242    virtual unsigned getJumpTableEncoding(void) const;
243
244    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
245
246    /// ReplaceNodeResults - Replace the results of node with an illegal result
247    /// type with new values built out of custom code.
248    ///
249    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
250                                    SelectionDAG &DAG) const;
251
252    virtual const char *getTargetNodeName(unsigned Opcode) const;
253
254    /// getSetCCResultType - Return the value type to use for ISD::SETCC.
255    virtual EVT getSetCCResultType(EVT VT) const;
256
257    virtual MachineBasicBlock *
258      EmitInstrWithCustomInserter(MachineInstr *MI,
259                                  MachineBasicBlock *MBB) const;
260
261    virtual void
262    AdjustInstrPostInstrSelection(MachineInstr *MI, SDNode *Node) const;
263
264    SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const;
265    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
266
267    bool isDesirableToTransformToIntegerOp(unsigned Opc, EVT VT) const;
268
269    /// allowsUnalignedMemoryAccesses - Returns true if the target allows
270    /// unaligned memory accesses. of the specified type.
271    virtual bool allowsUnalignedMemoryAccesses(EVT VT) const;
272
273    virtual EVT getOptimalMemOpType(uint64_t Size,
274                                    unsigned DstAlign, unsigned SrcAlign,
275                                    bool IsZeroVal,
276                                    bool MemcpyStrSrc,
277                                    MachineFunction &MF) const;
278
279    /// isLegalAddressingMode - Return true if the addressing mode represented
280    /// by AM is legal for this target, for a load/store of the specified type.
281    virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty)const;
282    bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
283
284    /// isLegalICmpImmediate - Return true if the specified immediate is legal
285    /// icmp immediate, that is the target has icmp instructions which can
286    /// compare a register against the immediate without having to materialize
287    /// the immediate into a register.
288    virtual bool isLegalICmpImmediate(int64_t Imm) const;
289
290    /// isLegalAddImmediate - Return true if the specified immediate is legal
291    /// add immediate, that is the target has add instructions which can
292    /// add a register and the immediate without having to materialize
293    /// the immediate into a register.
294    virtual bool isLegalAddImmediate(int64_t Imm) const;
295
296    /// getPreIndexedAddressParts - returns true by value, base pointer and
297    /// offset pointer and addressing mode by reference if the node's address
298    /// can be legally represented as pre-indexed load / store address.
299    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
300                                           SDValue &Offset,
301                                           ISD::MemIndexedMode &AM,
302                                           SelectionDAG &DAG) const;
303
304    /// getPostIndexedAddressParts - returns true by value, base pointer and
305    /// offset pointer and addressing mode by reference if this node can be
306    /// combined with a load / store to form a post-indexed load / store.
307    virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
308                                            SDValue &Base, SDValue &Offset,
309                                            ISD::MemIndexedMode &AM,
310                                            SelectionDAG &DAG) const;
311
312    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
313                                                const APInt &Mask,
314                                                APInt &KnownZero,
315                                                APInt &KnownOne,
316                                                const SelectionDAG &DAG,
317                                                unsigned Depth) const;
318
319
320    virtual bool ExpandInlineAsm(CallInst *CI) const;
321
322    ConstraintType getConstraintType(const std::string &Constraint) const;
323
324    /// Examine constraint string and operand type and determine a weight value.
325    /// The operand object must already have been set up with the operand type.
326    ConstraintWeight getSingleConstraintMatchWeight(
327      AsmOperandInfo &info, const char *constraint) const;
328
329    std::pair<unsigned, const TargetRegisterClass*>
330      getRegForInlineAsmConstraint(const std::string &Constraint,
331                                   EVT VT) const;
332
333    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
334    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
335    /// true it means one of the asm constraint of the inline asm instruction
336    /// being processed is 'm'.
337    virtual void LowerAsmOperandForConstraint(SDValue Op,
338                                              std::string &Constraint,
339                                              std::vector<SDValue> &Ops,
340                                              SelectionDAG &DAG) const;
341
342    const ARMSubtarget* getSubtarget() const {
343      return Subtarget;
344    }
345
346    /// getRegClassFor - Return the register class that should be used for the
347    /// specified value type.
348    virtual const TargetRegisterClass *getRegClassFor(EVT VT) const;
349
350    /// getMaximalGlobalOffset - Returns the maximal possible offset which can
351    /// be used for loads / stores from the global.
352    virtual unsigned getMaximalGlobalOffset() const;
353
354    /// createFastISel - This method returns a target specific FastISel object,
355    /// or null if the target does not support "fast" ISel.
356    virtual FastISel *createFastISel(FunctionLoweringInfo &funcInfo) const;
357
358    Sched::Preference getSchedulingPreference(SDNode *N) const;
359
360    bool isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const;
361    bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
362
363    /// isFPImmLegal - Returns true if the target can instruction select the
364    /// specified FP immediate natively. If false, the legalizer will
365    /// materialize the FP immediate as a load from a constant pool.
366    virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const;
367
368    virtual bool getTgtMemIntrinsic(IntrinsicInfo &Info,
369                                    const CallInst &I,
370                                    unsigned Intrinsic) const;
371  protected:
372    std::pair<const TargetRegisterClass*, uint8_t>
373    findRepresentativeClass(EVT VT) const;
374
375  private:
376    /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
377    /// make the right decision when generating code for different targets.
378    const ARMSubtarget *Subtarget;
379
380    const TargetRegisterInfo *RegInfo;
381
382    const InstrItineraryData *Itins;
383
384    /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
385    ///
386    unsigned ARMPCLabelIndex;
387
388    void addTypeForNEON(EVT VT, EVT PromotedLdStVT, EVT PromotedBitwiseVT);
389    void addDRTypeForNEON(EVT VT);
390    void addQRTypeForNEON(EVT VT);
391
392    typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
393    void PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
394                          SDValue Chain, SDValue &Arg,
395                          RegsToPassVector &RegsToPass,
396                          CCValAssign &VA, CCValAssign &NextVA,
397                          SDValue &StackPtr,
398                          SmallVector<SDValue, 8> &MemOpChains,
399                          ISD::ArgFlagsTy Flags) const;
400    SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
401                                 SDValue &Root, SelectionDAG &DAG,
402                                 DebugLoc dl) const;
403
404    CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
405                                  bool isVarArg) const;
406    SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
407                             DebugLoc dl, SelectionDAG &DAG,
408                             const CCValAssign &VA,
409                             ISD::ArgFlagsTy Flags) const;
410    SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
411    SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
412    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
413                                    const ARMSubtarget *Subtarget) const;
414    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
415    SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
416    SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
417    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
418    SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
419                                            SelectionDAG &DAG) const;
420    SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
421                                   SelectionDAG &DAG) const;
422    SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
423    SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
424    SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
425    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
426    SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
427    SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
428    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
429    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
430    SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
431    SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
432    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
433    SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
434                              const ARMSubtarget *ST) const;
435
436    SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
437
438    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
439                            CallingConv::ID CallConv, bool isVarArg,
440                            const SmallVectorImpl<ISD::InputArg> &Ins,
441                            DebugLoc dl, SelectionDAG &DAG,
442                            SmallVectorImpl<SDValue> &InVals) const;
443
444    virtual SDValue
445      LowerFormalArguments(SDValue Chain,
446                           CallingConv::ID CallConv, bool isVarArg,
447                           const SmallVectorImpl<ISD::InputArg> &Ins,
448                           DebugLoc dl, SelectionDAG &DAG,
449                           SmallVectorImpl<SDValue> &InVals) const;
450
451    void VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
452                              DebugLoc dl, SDValue &Chain, unsigned ArgOffset)
453      const;
454
455    void computeRegArea(CCState &CCInfo, MachineFunction &MF,
456                        unsigned &VARegSize, unsigned &VARegSaveSize) const;
457
458    virtual SDValue
459      LowerCall(SDValue Chain, SDValue Callee,
460                CallingConv::ID CallConv, bool isVarArg,
461                bool &isTailCall,
462                const SmallVectorImpl<ISD::OutputArg> &Outs,
463                const SmallVectorImpl<SDValue> &OutVals,
464                const SmallVectorImpl<ISD::InputArg> &Ins,
465                DebugLoc dl, SelectionDAG &DAG,
466                SmallVectorImpl<SDValue> &InVals) const;
467
468    /// HandleByVal - Target-specific cleanup for ByVal support.
469    virtual void HandleByVal(CCState *, unsigned &) const;
470
471    /// IsEligibleForTailCallOptimization - Check whether the call is eligible
472    /// for tail call optimization. Targets which want to do tail call
473    /// optimization should implement this function.
474    bool IsEligibleForTailCallOptimization(SDValue Callee,
475                                           CallingConv::ID CalleeCC,
476                                           bool isVarArg,
477                                           bool isCalleeStructRet,
478                                           bool isCallerStructRet,
479                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
480                                    const SmallVectorImpl<SDValue> &OutVals,
481                                    const SmallVectorImpl<ISD::InputArg> &Ins,
482                                           SelectionDAG& DAG) const;
483    virtual SDValue
484      LowerReturn(SDValue Chain,
485                  CallingConv::ID CallConv, bool isVarArg,
486                  const SmallVectorImpl<ISD::OutputArg> &Outs,
487                  const SmallVectorImpl<SDValue> &OutVals,
488                  DebugLoc dl, SelectionDAG &DAG) const;
489
490    virtual bool isUsedByReturnOnly(SDNode *N) const;
491
492    virtual bool mayBeEmittedAsTailCall(CallInst *CI) const;
493
494    SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
495                      SDValue &ARMcc, SelectionDAG &DAG, DebugLoc dl) const;
496    SDValue getVFPCmp(SDValue LHS, SDValue RHS,
497                      SelectionDAG &DAG, DebugLoc dl) const;
498    SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
499
500    SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
501
502    MachineBasicBlock *EmitAtomicCmpSwap(MachineInstr *MI,
503                                         MachineBasicBlock *BB,
504                                         unsigned Size) const;
505    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
506                                        MachineBasicBlock *BB,
507                                        unsigned Size,
508                                        unsigned BinOpcode) const;
509    MachineBasicBlock *EmitAtomicBinary64(MachineInstr *MI,
510                                          MachineBasicBlock *BB,
511                                          unsigned Op1,
512                                          unsigned Op2,
513                                          bool NeedsCarry = false,
514                                          bool IsCmpxchg = false) const;
515    MachineBasicBlock * EmitAtomicBinaryMinMax(MachineInstr *MI,
516                                               MachineBasicBlock *BB,
517                                               unsigned Size,
518                                               bool signExtend,
519                                               ARMCC::CondCodes Cond) const;
520
521    void SetupEntryBlockForSjLj(MachineInstr *MI,
522                                MachineBasicBlock *MBB,
523                                MachineBasicBlock *DispatchBB, int FI) const;
524
525    MachineBasicBlock *EmitSjLjDispatchBlock(MachineInstr *MI,
526                                             MachineBasicBlock *MBB) const;
527
528    bool RemapAddSubWithFlags(MachineInstr *MI, MachineBasicBlock *BB) const;
529  };
530
531  enum NEONModImmType {
532    VMOVModImm,
533    VMVNModImm,
534    OtherModImm
535  };
536
537
538  namespace ARM {
539    FastISel *createFastISel(FunctionLoweringInfo &funcInfo);
540  }
541}
542
543#endif  // ARMISELLOWERING_H
544