ARMISelLowering.h revision d966817f3cb87897cbec29c967b974924fe939ba
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      WrapperJT,    // WrapperJT - A wrapper node for TargetJumpTable
38
39      CALL,         // Function call.
40      CALL_PRED,    // Function call that's predicable.
41      CALL_NOLINK,  // Function call with branch not branch-and-link.
42      tCALL,        // Thumb function call.
43      BRCOND,       // Conditional branch.
44      BR_JT,        // Jumptable branch.
45      BR2_JT,       // Jumptable branch (2 level - jumptable entry is a jump).
46      RET_FLAG,     // Return with a flag operand.
47
48      PIC_ADD,      // Add with a PC operand and a PIC label.
49
50      CMP,          // ARM compare instructions.
51      CMPZ,         // ARM compare that sets only Z flag.
52      CMPFP,        // ARM VFP compare instruction, sets FPSCR.
53      CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
54      FMSTAT,       // ARM fmstat instruction.
55      CMOV,         // ARM conditional move instructions.
56      CNEG,         // ARM conditional negate instructions.
57
58      BCC_i64,
59
60      RBIT,         // ARM bitreverse instruction
61
62      FTOSI,        // FP to sint within a FP register.
63      FTOUI,        // FP to uint within a FP register.
64      SITOF,        // sint to FP within a FP register.
65      UITOF,        // uint to FP within a FP register.
66
67      SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
68      SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
69      RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
70
71      VMOVRRD,      // double to two gprs.
72      VMOVDRR,      // Two gprs to double.
73
74      EH_SJLJ_SETJMP,         // SjLj exception handling setjmp.
75      EH_SJLJ_LONGJMP,        // SjLj exception handling longjmp.
76      EH_SJLJ_DISPATCHSETUP,  // SjLj exception handling dispatch setup.
77
78      TC_RETURN,    // Tail call return pseudo.
79
80      THREAD_POINTER,
81
82      DYN_ALLOC,    // Dynamic allocation on the stack.
83
84      MEMBARRIER,   // Memory barrier (DMB)
85      MEMBARRIER_MCR, // Memory barrier (MCR)
86
87      PRELOAD,      // Preload
88
89      VCEQ,         // Vector compare equal.
90      VCGE,         // Vector compare greater than or equal.
91      VCGEU,        // Vector compare unsigned greater than or equal.
92      VCGT,         // Vector compare greater than.
93      VCGTU,        // Vector compare unsigned greater than.
94      VTST,         // Vector test bits.
95
96      // Vector shift by immediate:
97      VSHL,         // ...left
98      VSHRs,        // ...right (signed)
99      VSHRu,        // ...right (unsigned)
100      VSHLLs,       // ...left long (signed)
101      VSHLLu,       // ...left long (unsigned)
102      VSHLLi,       // ...left long (with maximum shift count)
103      VSHRN,        // ...right narrow
104
105      // Vector rounding shift by immediate:
106      VRSHRs,       // ...right (signed)
107      VRSHRu,       // ...right (unsigned)
108      VRSHRN,       // ...right narrow
109
110      // Vector saturating shift by immediate:
111      VQSHLs,       // ...left (signed)
112      VQSHLu,       // ...left (unsigned)
113      VQSHLsu,      // ...left (signed to unsigned)
114      VQSHRNs,      // ...right narrow (signed)
115      VQSHRNu,      // ...right narrow (unsigned)
116      VQSHRNsu,     // ...right narrow (signed to unsigned)
117
118      // Vector saturating rounding shift by immediate:
119      VQRSHRNs,     // ...right narrow (signed)
120      VQRSHRNu,     // ...right narrow (unsigned)
121      VQRSHRNsu,    // ...right narrow (signed to unsigned)
122
123      // Vector shift and insert:
124      VSLI,         // ...left
125      VSRI,         // ...right
126
127      // Vector get lane (VMOV scalar to ARM core register)
128      // (These are used for 8- and 16-bit element types only.)
129      VGETLANEu,    // zero-extend vector extract element
130      VGETLANEs,    // sign-extend vector extract element
131
132      // Vector move immediate and move negated immediate:
133      VMOVIMM,
134      VMVNIMM,
135
136      // Vector duplicate:
137      VDUP,
138      VDUPLANE,
139
140      // Vector shuffles:
141      VEXT,         // extract
142      VREV64,       // reverse elements within 64-bit doublewords
143      VREV32,       // reverse elements within 32-bit words
144      VREV16,       // reverse elements within 16-bit halfwords
145      VZIP,         // zip (interleave)
146      VUZP,         // unzip (deinterleave)
147      VTRN,         // transpose
148
149      // Vector multiply long:
150      VMULLs,       // ...signed
151      VMULLu,       // ...unsigned
152
153      // Operands of the standard BUILD_VECTOR node are not legalized, which
154      // is fine if BUILD_VECTORs are always lowered to shuffles or other
155      // operations, but for ARM some BUILD_VECTORs are legal as-is and their
156      // operands need to be legalized.  Define an ARM-specific version of
157      // BUILD_VECTOR for this purpose.
158      BUILD_VECTOR,
159
160      // Floating-point max and min:
161      FMAX,
162      FMIN,
163
164      // Bit-field insert
165      BFI,
166
167      // Vector OR with immediate
168      VORRIMM
169    };
170  }
171
172  /// Define some predicates that are used for node matching.
173  namespace ARM {
174    /// getVFPf32Imm / getVFPf64Imm - If the given fp immediate can be
175    /// materialized with a VMOV.f32 / VMOV.f64 (i.e. fconsts / fconstd)
176    /// instruction, returns its 8-bit integer representation. Otherwise,
177    /// returns -1.
178    int getVFPf32Imm(const APFloat &FPImm);
179    int getVFPf64Imm(const APFloat &FPImm);
180    bool isBitFieldInvertedMask(unsigned v);
181  }
182
183  //===--------------------------------------------------------------------===//
184  //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
185
186  class ARMTargetLowering : public TargetLowering {
187  public:
188    explicit ARMTargetLowering(TargetMachine &TM);
189
190    virtual unsigned getJumpTableEncoding(void) const;
191
192    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
193
194    /// ReplaceNodeResults - Replace the results of node with an illegal result
195    /// type with new values built out of custom code.
196    ///
197    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
198                                    SelectionDAG &DAG) const;
199
200    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
201
202    virtual const char *getTargetNodeName(unsigned Opcode) const;
203
204    virtual MachineBasicBlock *
205      EmitInstrWithCustomInserter(MachineInstr *MI,
206                                  MachineBasicBlock *MBB) const;
207
208    /// allowsUnalignedMemoryAccesses - Returns true if the target allows
209    /// unaligned memory accesses. of the specified type.
210    /// FIXME: Add getOptimalMemOpType to implement memcpy with NEON?
211    virtual bool allowsUnalignedMemoryAccesses(EVT VT) const;
212
213    /// isLegalAddressingMode - Return true if the addressing mode represented
214    /// by AM is legal for this target, for a load/store of the specified type.
215    virtual bool isLegalAddressingMode(const AddrMode &AM, const Type *Ty)const;
216    bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
217
218    /// isLegalICmpImmediate - Return true if the specified immediate is legal
219    /// icmp immediate, that is the target has icmp instructions which can
220    /// compare a register against the immediate without having to materialize
221    /// the immediate into a register.
222    virtual bool isLegalICmpImmediate(int64_t Imm) const;
223
224    /// getPreIndexedAddressParts - returns true by value, base pointer and
225    /// offset pointer and addressing mode by reference if the node's address
226    /// can be legally represented as pre-indexed load / store address.
227    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
228                                           SDValue &Offset,
229                                           ISD::MemIndexedMode &AM,
230                                           SelectionDAG &DAG) const;
231
232    /// getPostIndexedAddressParts - returns true by value, base pointer and
233    /// offset pointer and addressing mode by reference if this node can be
234    /// combined with a load / store to form a post-indexed load / store.
235    virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
236                                            SDValue &Base, SDValue &Offset,
237                                            ISD::MemIndexedMode &AM,
238                                            SelectionDAG &DAG) const;
239
240    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
241                                                const APInt &Mask,
242                                                APInt &KnownZero,
243                                                APInt &KnownOne,
244                                                const SelectionDAG &DAG,
245                                                unsigned Depth) const;
246
247
248    ConstraintType getConstraintType(const std::string &Constraint) const;
249
250    /// Examine constraint string and operand type and determine a weight value.
251    /// The operand object must already have been set up with the operand type.
252    ConstraintWeight getSingleConstraintMatchWeight(
253      AsmOperandInfo &info, const char *constraint) const;
254
255    std::pair<unsigned, const TargetRegisterClass*>
256      getRegForInlineAsmConstraint(const std::string &Constraint,
257                                   EVT VT) const;
258    std::vector<unsigned>
259    getRegClassForInlineAsmConstraint(const std::string &Constraint,
260                                      EVT VT) const;
261
262    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
263    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
264    /// true it means one of the asm constraint of the inline asm instruction
265    /// being processed is 'm'.
266    virtual void LowerAsmOperandForConstraint(SDValue Op,
267                                              char ConstraintLetter,
268                                              std::vector<SDValue> &Ops,
269                                              SelectionDAG &DAG) const;
270
271    const ARMSubtarget* getSubtarget() const {
272      return Subtarget;
273    }
274
275    /// getRegClassFor - Return the register class that should be used for the
276    /// specified value type.
277    virtual TargetRegisterClass *getRegClassFor(EVT VT) const;
278
279    /// getFunctionAlignment - Return the Log2 alignment of this function.
280    virtual unsigned getFunctionAlignment(const Function *F) const;
281
282    /// getMaximalGlobalOffset - Returns the maximal possible offset which can
283    /// be used for loads / stores from the global.
284    virtual unsigned getMaximalGlobalOffset() const;
285
286    /// createFastISel - This method returns a target specific FastISel object,
287    /// or null if the target does not support "fast" ISel.
288    virtual FastISel *createFastISel(FunctionLoweringInfo &funcInfo) const;
289
290    Sched::Preference getSchedulingPreference(SDNode *N) const;
291
292    unsigned getRegPressureLimit(const TargetRegisterClass *RC,
293                                 MachineFunction &MF) const;
294
295    bool isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const;
296    bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
297
298    /// isFPImmLegal - Returns true if the target can instruction select the
299    /// specified FP immediate natively. If false, the legalizer will
300    /// materialize the FP immediate as a load from a constant pool.
301    virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const;
302
303    virtual bool getTgtMemIntrinsic(IntrinsicInfo &Info,
304                                    const CallInst &I,
305                                    unsigned Intrinsic) const;
306  protected:
307    std::pair<const TargetRegisterClass*, uint8_t>
308    findRepresentativeClass(EVT VT) const;
309
310  private:
311    /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
312    /// make the right decision when generating code for different targets.
313    const ARMSubtarget *Subtarget;
314
315    const TargetRegisterInfo *RegInfo;
316
317    const InstrItineraryData *Itins;
318
319    /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
320    ///
321    unsigned ARMPCLabelIndex;
322
323    void addTypeForNEON(EVT VT, EVT PromotedLdStVT, EVT PromotedBitwiseVT);
324    void addDRTypeForNEON(EVT VT);
325    void addQRTypeForNEON(EVT VT);
326
327    typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
328    void PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
329                          SDValue Chain, SDValue &Arg,
330                          RegsToPassVector &RegsToPass,
331                          CCValAssign &VA, CCValAssign &NextVA,
332                          SDValue &StackPtr,
333                          SmallVector<SDValue, 8> &MemOpChains,
334                          ISD::ArgFlagsTy Flags) const;
335    SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
336                                 SDValue &Root, SelectionDAG &DAG,
337                                 DebugLoc dl) const;
338
339    CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
340                                  bool isVarArg) const;
341    SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
342                             DebugLoc dl, SelectionDAG &DAG,
343                             const CCValAssign &VA,
344                             ISD::ArgFlagsTy Flags) const;
345    SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
346    SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
347    SDValue LowerEH_SJLJ_DISPATCHSETUP(SDValue Op, SelectionDAG &DAG) const;
348    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
349                                    const ARMSubtarget *Subtarget) const;
350    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
351    SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
352    SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
353    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
354    SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
355                                            SelectionDAG &DAG) const;
356    SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
357                                   SelectionDAG &DAG) const;
358    SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
359    SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
360    SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
361    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
362    SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
363    SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
364    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
365    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
366    SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
367    SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
368    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
369
370    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
371                            CallingConv::ID CallConv, bool isVarArg,
372                            const SmallVectorImpl<ISD::InputArg> &Ins,
373                            DebugLoc dl, SelectionDAG &DAG,
374                            SmallVectorImpl<SDValue> &InVals) const;
375
376    virtual SDValue
377      LowerFormalArguments(SDValue Chain,
378                           CallingConv::ID CallConv, bool isVarArg,
379                           const SmallVectorImpl<ISD::InputArg> &Ins,
380                           DebugLoc dl, SelectionDAG &DAG,
381                           SmallVectorImpl<SDValue> &InVals) const;
382
383    virtual SDValue
384      LowerCall(SDValue Chain, SDValue Callee,
385                CallingConv::ID CallConv, bool isVarArg,
386                bool &isTailCall,
387                const SmallVectorImpl<ISD::OutputArg> &Outs,
388                const SmallVectorImpl<SDValue> &OutVals,
389                const SmallVectorImpl<ISD::InputArg> &Ins,
390                DebugLoc dl, SelectionDAG &DAG,
391                SmallVectorImpl<SDValue> &InVals) const;
392
393    /// IsEligibleForTailCallOptimization - Check whether the call is eligible
394    /// for tail call optimization. Targets which want to do tail call
395    /// optimization should implement this function.
396    bool IsEligibleForTailCallOptimization(SDValue Callee,
397                                           CallingConv::ID CalleeCC,
398                                           bool isVarArg,
399                                           bool isCalleeStructRet,
400                                           bool isCallerStructRet,
401                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
402                                    const SmallVectorImpl<SDValue> &OutVals,
403                                    const SmallVectorImpl<ISD::InputArg> &Ins,
404                                           SelectionDAG& DAG) const;
405    virtual SDValue
406      LowerReturn(SDValue Chain,
407                  CallingConv::ID CallConv, bool isVarArg,
408                  const SmallVectorImpl<ISD::OutputArg> &Outs,
409                  const SmallVectorImpl<SDValue> &OutVals,
410                  DebugLoc dl, SelectionDAG &DAG) const;
411
412    SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
413                      SDValue &ARMcc, SelectionDAG &DAG, DebugLoc dl) const;
414    SDValue getVFPCmp(SDValue LHS, SDValue RHS,
415                      SelectionDAG &DAG, DebugLoc dl) const;
416
417    SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
418
419    MachineBasicBlock *EmitAtomicCmpSwap(MachineInstr *MI,
420                                         MachineBasicBlock *BB,
421                                         unsigned Size) const;
422    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
423                                        MachineBasicBlock *BB,
424                                        unsigned Size,
425                                        unsigned BinOpcode) const;
426
427  };
428
429  namespace ARM {
430    FastISel *createFastISel(FunctionLoweringInfo &funcInfo);
431  }
432}
433
434#endif  // ARMISELLOWERING_H
435