ARMISelLowering.h revision 4d3f3294535a3b622c715f2d9675d4f3e86c3378
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      EH_SJLJ_DISPATCHSETUP,  // SjLj exception handling dispatch setup.
85
86      TC_RETURN,    // Tail call return pseudo.
87
88      THREAD_POINTER,
89
90      DYN_ALLOC,    // Dynamic allocation on the stack.
91
92      MEMBARRIER,   // Memory barrier (DMB)
93      MEMBARRIER_MCR, // Memory barrier (MCR)
94
95      PRELOAD,      // Preload
96
97      VCEQ,         // Vector compare equal.
98      VCEQZ,        // Vector compare equal to zero.
99      VCGE,         // Vector compare greater than or equal.
100      VCGEZ,        // Vector compare greater than or equal to zero.
101      VCLEZ,        // Vector compare less than or equal to zero.
102      VCGEU,        // Vector compare unsigned greater than or equal.
103      VCGT,         // Vector compare greater than.
104      VCGTZ,        // Vector compare greater than zero.
105      VCLTZ,        // Vector compare less than zero.
106      VCGTU,        // Vector compare unsigned greater than.
107      VTST,         // Vector test bits.
108
109      // Vector shift by immediate:
110      VSHL,         // ...left
111      VSHRs,        // ...right (signed)
112      VSHRu,        // ...right (unsigned)
113      VSHLLs,       // ...left long (signed)
114      VSHLLu,       // ...left long (unsigned)
115      VSHLLi,       // ...left long (with maximum shift count)
116      VSHRN,        // ...right narrow
117
118      // Vector rounding shift by immediate:
119      VRSHRs,       // ...right (signed)
120      VRSHRu,       // ...right (unsigned)
121      VRSHRN,       // ...right narrow
122
123      // Vector saturating shift by immediate:
124      VQSHLs,       // ...left (signed)
125      VQSHLu,       // ...left (unsigned)
126      VQSHLsu,      // ...left (signed to unsigned)
127      VQSHRNs,      // ...right narrow (signed)
128      VQSHRNu,      // ...right narrow (unsigned)
129      VQSHRNsu,     // ...right narrow (signed to unsigned)
130
131      // Vector saturating rounding shift by immediate:
132      VQRSHRNs,     // ...right narrow (signed)
133      VQRSHRNu,     // ...right narrow (unsigned)
134      VQRSHRNsu,    // ...right narrow (signed to unsigned)
135
136      // Vector shift and insert:
137      VSLI,         // ...left
138      VSRI,         // ...right
139
140      // Vector get lane (VMOV scalar to ARM core register)
141      // (These are used for 8- and 16-bit element types only.)
142      VGETLANEu,    // zero-extend vector extract element
143      VGETLANEs,    // sign-extend vector extract element
144
145      // Vector move immediate and move negated immediate:
146      VMOVIMM,
147      VMVNIMM,
148
149      // Vector duplicate:
150      VDUP,
151      VDUPLANE,
152
153      // Vector shuffles:
154      VEXT,         // extract
155      VREV64,       // reverse elements within 64-bit doublewords
156      VREV32,       // reverse elements within 32-bit words
157      VREV16,       // reverse elements within 16-bit halfwords
158      VZIP,         // zip (interleave)
159      VUZP,         // unzip (deinterleave)
160      VTRN,         // transpose
161      VTBL1,        // 1-register shuffle with mask
162      VTBL2,        // 2-register shuffle with mask
163
164      // Vector multiply long:
165      VMULLs,       // ...signed
166      VMULLu,       // ...unsigned
167
168      // Operands of the standard BUILD_VECTOR node are not legalized, which
169      // is fine if BUILD_VECTORs are always lowered to shuffles or other
170      // operations, but for ARM some BUILD_VECTORs are legal as-is and their
171      // operands need to be legalized.  Define an ARM-specific version of
172      // BUILD_VECTOR for this purpose.
173      BUILD_VECTOR,
174
175      // Floating-point max and min:
176      FMAX,
177      FMIN,
178
179      // Bit-field insert
180      BFI,
181
182      // Vector OR with immediate
183      VORRIMM,
184      // Vector AND with NOT of immediate
185      VBICIMM,
186
187      // Vector bitwise select
188      VBSL,
189
190      // Vector load N-element structure to all lanes:
191      VLD2DUP = ISD::FIRST_TARGET_MEMORY_OPCODE,
192      VLD3DUP,
193      VLD4DUP,
194
195      // NEON loads with post-increment base updates:
196      VLD1_UPD,
197      VLD2_UPD,
198      VLD3_UPD,
199      VLD4_UPD,
200      VLD2LN_UPD,
201      VLD3LN_UPD,
202      VLD4LN_UPD,
203      VLD2DUP_UPD,
204      VLD3DUP_UPD,
205      VLD4DUP_UPD,
206
207      // NEON stores with post-increment base updates:
208      VST1_UPD,
209      VST2_UPD,
210      VST3_UPD,
211      VST4_UPD,
212      VST2LN_UPD,
213      VST3LN_UPD,
214      VST4LN_UPD,
215
216      // 64-bit atomic ops (value split into two registers)
217      ATOMADD64_DAG,
218      ATOMSUB64_DAG,
219      ATOMOR64_DAG,
220      ATOMXOR64_DAG,
221      ATOMAND64_DAG,
222      ATOMNAND64_DAG,
223      ATOMSWAP64_DAG,
224      ATOMCMPXCHG64_DAG
225    };
226  }
227
228  /// Define some predicates that are used for node matching.
229  namespace ARM {
230    /// getVFPf32Imm / getVFPf64Imm - If the given fp immediate can be
231    /// materialized with a VMOV.f32 / VMOV.f64 (i.e. fconsts / fconstd)
232    /// instruction, returns its 8-bit integer representation. Otherwise,
233    /// returns -1.
234    int getVFPf32Imm(const APFloat &FPImm);
235    int getVFPf64Imm(const APFloat &FPImm);
236    bool isBitFieldInvertedMask(unsigned v);
237  }
238
239  //===--------------------------------------------------------------------===//
240  //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
241
242  class ARMTargetLowering : public TargetLowering {
243  public:
244    explicit ARMTargetLowering(TargetMachine &TM);
245
246    virtual unsigned getJumpTableEncoding(void) const;
247
248    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
249
250    /// ReplaceNodeResults - Replace the results of node with an illegal result
251    /// type with new values built out of custom code.
252    ///
253    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
254                                    SelectionDAG &DAG) const;
255
256    virtual const char *getTargetNodeName(unsigned Opcode) const;
257
258    virtual MachineBasicBlock *
259      EmitInstrWithCustomInserter(MachineInstr *MI,
260                                  MachineBasicBlock *MBB) const;
261
262    virtual void
263    AdjustInstrPostInstrSelection(MachineInstr *MI, SDNode *Node) const;
264
265    SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const;
266    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
267
268    bool isDesirableToTransformToIntegerOp(unsigned Opc, EVT VT) const;
269
270    /// allowsUnalignedMemoryAccesses - Returns true if the target allows
271    /// unaligned memory accesses. of the specified type.
272    /// FIXME: Add getOptimalMemOpType to implement memcpy with NEON?
273    virtual bool allowsUnalignedMemoryAccesses(EVT VT) const;
274
275    /// isLegalAddressingMode - Return true if the addressing mode represented
276    /// by AM is legal for this target, for a load/store of the specified type.
277    virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty)const;
278    bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
279
280    /// isLegalICmpImmediate - Return true if the specified immediate is legal
281    /// icmp immediate, that is the target has icmp instructions which can
282    /// compare a register against the immediate without having to materialize
283    /// the immediate into a register.
284    virtual bool isLegalICmpImmediate(int64_t Imm) const;
285
286    /// isLegalAddImmediate - Return true if the specified immediate is legal
287    /// add immediate, that is the target has add instructions which can
288    /// add a register and the immediate without having to materialize
289    /// the immediate into a register.
290    virtual bool isLegalAddImmediate(int64_t Imm) const;
291
292    /// getPreIndexedAddressParts - returns true by value, base pointer and
293    /// offset pointer and addressing mode by reference if the node's address
294    /// can be legally represented as pre-indexed load / store address.
295    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
296                                           SDValue &Offset,
297                                           ISD::MemIndexedMode &AM,
298                                           SelectionDAG &DAG) const;
299
300    /// getPostIndexedAddressParts - returns true by value, base pointer and
301    /// offset pointer and addressing mode by reference if this node can be
302    /// combined with a load / store to form a post-indexed load / store.
303    virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
304                                            SDValue &Base, SDValue &Offset,
305                                            ISD::MemIndexedMode &AM,
306                                            SelectionDAG &DAG) const;
307
308    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
309                                                const APInt &Mask,
310                                                APInt &KnownZero,
311                                                APInt &KnownOne,
312                                                const SelectionDAG &DAG,
313                                                unsigned Depth) const;
314
315
316    virtual bool ExpandInlineAsm(CallInst *CI) const;
317
318    ConstraintType getConstraintType(const std::string &Constraint) const;
319
320    /// Examine constraint string and operand type and determine a weight value.
321    /// The operand object must already have been set up with the operand type.
322    ConstraintWeight getSingleConstraintMatchWeight(
323      AsmOperandInfo &info, const char *constraint) const;
324
325    std::pair<unsigned, const TargetRegisterClass*>
326      getRegForInlineAsmConstraint(const std::string &Constraint,
327                                   EVT VT) const;
328
329    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
330    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
331    /// true it means one of the asm constraint of the inline asm instruction
332    /// being processed is 'm'.
333    virtual void LowerAsmOperandForConstraint(SDValue Op,
334                                              std::string &Constraint,
335                                              std::vector<SDValue> &Ops,
336                                              SelectionDAG &DAG) const;
337
338    const ARMSubtarget* getSubtarget() const {
339      return Subtarget;
340    }
341
342    /// getRegClassFor - Return the register class that should be used for the
343    /// specified value type.
344    virtual TargetRegisterClass *getRegClassFor(EVT VT) const;
345
346    /// getMaximalGlobalOffset - Returns the maximal possible offset which can
347    /// be used for loads / stores from the global.
348    virtual unsigned getMaximalGlobalOffset() const;
349
350    /// createFastISel - This method returns a target specific FastISel object,
351    /// or null if the target does not support "fast" ISel.
352    virtual FastISel *createFastISel(FunctionLoweringInfo &funcInfo) const;
353
354    Sched::Preference getSchedulingPreference(SDNode *N) const;
355
356    bool isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const;
357    bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
358
359    /// isFPImmLegal - Returns true if the target can instruction select the
360    /// specified FP immediate natively. If false, the legalizer will
361    /// materialize the FP immediate as a load from a constant pool.
362    virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const;
363
364    virtual bool getTgtMemIntrinsic(IntrinsicInfo &Info,
365                                    const CallInst &I,
366                                    unsigned Intrinsic) const;
367  protected:
368    std::pair<const TargetRegisterClass*, uint8_t>
369    findRepresentativeClass(EVT VT) const;
370
371  private:
372    /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
373    /// make the right decision when generating code for different targets.
374    const ARMSubtarget *Subtarget;
375
376    const TargetRegisterInfo *RegInfo;
377
378    const InstrItineraryData *Itins;
379
380    /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
381    ///
382    unsigned ARMPCLabelIndex;
383
384    void addTypeForNEON(EVT VT, EVT PromotedLdStVT, EVT PromotedBitwiseVT);
385    void addDRTypeForNEON(EVT VT);
386    void addQRTypeForNEON(EVT VT);
387
388    typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
389    void PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
390                          SDValue Chain, SDValue &Arg,
391                          RegsToPassVector &RegsToPass,
392                          CCValAssign &VA, CCValAssign &NextVA,
393                          SDValue &StackPtr,
394                          SmallVector<SDValue, 8> &MemOpChains,
395                          ISD::ArgFlagsTy Flags) const;
396    SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
397                                 SDValue &Root, SelectionDAG &DAG,
398                                 DebugLoc dl) const;
399
400    CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
401                                  bool isVarArg) const;
402    SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
403                             DebugLoc dl, SelectionDAG &DAG,
404                             const CCValAssign &VA,
405                             ISD::ArgFlagsTy Flags) const;
406    SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
407    SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
408    SDValue LowerEH_SJLJ_DISPATCHSETUP(SDValue Op, SelectionDAG &DAG) const;
409    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
410                                    const ARMSubtarget *Subtarget) const;
411    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
412    SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
413    SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
414    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
415    SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
416                                            SelectionDAG &DAG) const;
417    SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
418                                   SelectionDAG &DAG) const;
419    SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
420    SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
421    SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
422    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
423    SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
424    SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
425    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
426    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
427    SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
428    SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
429    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
430    SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
431                              const ARMSubtarget *ST) const;
432
433    SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
434
435    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
436                            CallingConv::ID CallConv, bool isVarArg,
437                            const SmallVectorImpl<ISD::InputArg> &Ins,
438                            DebugLoc dl, SelectionDAG &DAG,
439                            SmallVectorImpl<SDValue> &InVals) const;
440
441    virtual SDValue
442      LowerFormalArguments(SDValue Chain,
443                           CallingConv::ID CallConv, bool isVarArg,
444                           const SmallVectorImpl<ISD::InputArg> &Ins,
445                           DebugLoc dl, SelectionDAG &DAG,
446                           SmallVectorImpl<SDValue> &InVals) const;
447
448    void VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
449                              DebugLoc dl, SDValue &Chain, unsigned ArgOffset)
450      const;
451
452    void computeRegArea(CCState &CCInfo, MachineFunction &MF,
453                        unsigned &VARegSize, unsigned &VARegSaveSize) const;
454
455    virtual SDValue
456      LowerCall(SDValue Chain, SDValue Callee,
457                CallingConv::ID CallConv, bool isVarArg,
458                bool &isTailCall,
459                const SmallVectorImpl<ISD::OutputArg> &Outs,
460                const SmallVectorImpl<SDValue> &OutVals,
461                const SmallVectorImpl<ISD::InputArg> &Ins,
462                DebugLoc dl, SelectionDAG &DAG,
463                SmallVectorImpl<SDValue> &InVals) const;
464
465    /// HandleByVal - Target-specific cleanup for ByVal support.
466    virtual void HandleByVal(CCState *, unsigned &) const;
467
468    /// IsEligibleForTailCallOptimization - Check whether the call is eligible
469    /// for tail call optimization. Targets which want to do tail call
470    /// optimization should implement this function.
471    bool IsEligibleForTailCallOptimization(SDValue Callee,
472                                           CallingConv::ID CalleeCC,
473                                           bool isVarArg,
474                                           bool isCalleeStructRet,
475                                           bool isCallerStructRet,
476                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
477                                    const SmallVectorImpl<SDValue> &OutVals,
478                                    const SmallVectorImpl<ISD::InputArg> &Ins,
479                                           SelectionDAG& DAG) const;
480    virtual SDValue
481      LowerReturn(SDValue Chain,
482                  CallingConv::ID CallConv, bool isVarArg,
483                  const SmallVectorImpl<ISD::OutputArg> &Outs,
484                  const SmallVectorImpl<SDValue> &OutVals,
485                  DebugLoc dl, SelectionDAG &DAG) const;
486
487    virtual bool isUsedByReturnOnly(SDNode *N) const;
488
489    virtual bool mayBeEmittedAsTailCall(CallInst *CI) const;
490
491    SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
492                      SDValue &ARMcc, SelectionDAG &DAG, DebugLoc dl) const;
493    SDValue getVFPCmp(SDValue LHS, SDValue RHS,
494                      SelectionDAG &DAG, DebugLoc dl) const;
495    SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
496
497    SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
498
499    MachineBasicBlock *EmitAtomicCmpSwap(MachineInstr *MI,
500                                         MachineBasicBlock *BB,
501                                         unsigned Size) const;
502    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
503                                        MachineBasicBlock *BB,
504                                        unsigned Size,
505                                        unsigned BinOpcode) const;
506    MachineBasicBlock *EmitAtomicBinary64(MachineInstr *MI,
507                                          MachineBasicBlock *BB,
508                                          unsigned Op1,
509                                          unsigned Op2,
510                                          bool NeedsCarry = false,
511                                          bool IsCmpxchg = false) const;
512    MachineBasicBlock * EmitAtomicBinaryMinMax(MachineInstr *MI,
513                                               MachineBasicBlock *BB,
514                                               unsigned Size,
515                                               bool signExtend,
516                                               ARMCC::CondCodes Cond) const;
517
518    bool RemapAddSubWithFlags(MachineInstr *MI, MachineBasicBlock *BB) const;
519  };
520
521  enum NEONModImmType {
522    VMOVModImm,
523    VMVNModImm,
524    OtherModImm
525  };
526
527
528  namespace ARM {
529    FastISel *createFastISel(FunctionLoweringInfo &funcInfo);
530  }
531}
532
533#endif  // ARMISELLOWERING_H
534