1//===-- X86ISelLowering.h - X86 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 X86 uses to lower LLVM code into a
11// selection DAG.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef X86ISELLOWERING_H
16#define X86ISELLOWERING_H
17
18#include "X86MachineFunctionInfo.h"
19#include "X86RegisterInfo.h"
20#include "X86Subtarget.h"
21#include "llvm/CodeGen/CallingConvLower.h"
22#include "llvm/CodeGen/FastISel.h"
23#include "llvm/CodeGen/SelectionDAG.h"
24#include "llvm/Target/TargetLowering.h"
25#include "llvm/Target/TargetOptions.h"
26
27namespace llvm {
28  namespace X86ISD {
29    // X86 Specific DAG Nodes
30    enum NodeType {
31      // Start the numbering where the builtin ops leave off.
32      FIRST_NUMBER = ISD::BUILTIN_OP_END,
33
34      /// BSF - Bit scan forward.
35      /// BSR - Bit scan reverse.
36      BSF,
37      BSR,
38
39      /// SHLD, SHRD - Double shift instructions. These correspond to
40      /// X86::SHLDxx and X86::SHRDxx instructions.
41      SHLD,
42      SHRD,
43
44      /// FAND - Bitwise logical AND of floating point values. This corresponds
45      /// to X86::ANDPS or X86::ANDPD.
46      FAND,
47
48      /// FOR - Bitwise logical OR of floating point values. This corresponds
49      /// to X86::ORPS or X86::ORPD.
50      FOR,
51
52      /// FXOR - Bitwise logical XOR of floating point values. This corresponds
53      /// to X86::XORPS or X86::XORPD.
54      FXOR,
55
56      /// FAND - Bitwise logical ANDNOT of floating point values. This
57      /// corresponds to X86::ANDNPS or X86::ANDNPD.
58      FANDN,
59
60      /// FSRL - Bitwise logical right shift of floating point values. These
61      /// corresponds to X86::PSRLDQ.
62      FSRL,
63
64      /// CALL - These operations represent an abstract X86 call
65      /// instruction, which includes a bunch of information.  In particular the
66      /// operands of these node are:
67      ///
68      ///     #0 - The incoming token chain
69      ///     #1 - The callee
70      ///     #2 - The number of arg bytes the caller pushes on the stack.
71      ///     #3 - The number of arg bytes the callee pops off the stack.
72      ///     #4 - The value to pass in AL/AX/EAX (optional)
73      ///     #5 - The value to pass in DL/DX/EDX (optional)
74      ///
75      /// The result values of these nodes are:
76      ///
77      ///     #0 - The outgoing token chain
78      ///     #1 - The first register result value (optional)
79      ///     #2 - The second register result value (optional)
80      ///
81      CALL,
82
83      /// RDTSC_DAG - This operation implements the lowering for
84      /// readcyclecounter
85      RDTSC_DAG,
86
87      /// X86 compare and logical compare instructions.
88      CMP, COMI, UCOMI,
89
90      /// X86 bit-test instructions.
91      BT,
92
93      /// X86 SetCC. Operand 0 is condition code, and operand 1 is the EFLAGS
94      /// operand, usually produced by a CMP instruction.
95      SETCC,
96
97      // Same as SETCC except it's materialized with a sbb and the value is all
98      // one's or all zero's.
99      SETCC_CARRY,  // R = carry_bit ? ~0 : 0
100
101      /// X86 FP SETCC, implemented with CMP{cc}SS/CMP{cc}SD.
102      /// Operands are two FP values to compare; result is a mask of
103      /// 0s or 1s.  Generally DTRT for C/C++ with NaNs.
104      FSETCCss, FSETCCsd,
105
106      /// X86 MOVMSK{pd|ps}, extracts sign bits of two or four FP values,
107      /// result in an integer GPR.  Needs masking for scalar result.
108      FGETSIGNx86,
109
110      /// X86 conditional moves. Operand 0 and operand 1 are the two values
111      /// to select from. Operand 2 is the condition code, and operand 3 is the
112      /// flag operand produced by a CMP or TEST instruction. It also writes a
113      /// flag result.
114      CMOV,
115
116      /// X86 conditional branches. Operand 0 is the chain operand, operand 1
117      /// is the block to branch if condition is true, operand 2 is the
118      /// condition code, and operand 3 is the flag operand produced by a CMP
119      /// or TEST instruction.
120      BRCOND,
121
122      /// Return with a flag operand. Operand 0 is the chain operand, operand
123      /// 1 is the number of bytes of stack to pop.
124      RET_FLAG,
125
126      /// REP_STOS - Repeat fill, corresponds to X86::REP_STOSx.
127      REP_STOS,
128
129      /// REP_MOVS - Repeat move, corresponds to X86::REP_MOVSx.
130      REP_MOVS,
131
132      /// GlobalBaseReg - On Darwin, this node represents the result of the popl
133      /// at function entry, used for PIC code.
134      GlobalBaseReg,
135
136      /// Wrapper - A wrapper node for TargetConstantPool,
137      /// TargetExternalSymbol, and TargetGlobalAddress.
138      Wrapper,
139
140      /// WrapperRIP - Special wrapper used under X86-64 PIC mode for RIP
141      /// relative displacements.
142      WrapperRIP,
143
144      /// MOVDQ2Q - Copies a 64-bit value from the low word of an XMM vector
145      /// to an MMX vector.  If you think this is too close to the previous
146      /// mnemonic, so do I; blame Intel.
147      MOVDQ2Q,
148
149      /// MMX_MOVD2W - Copies a 32-bit value from the low word of a MMX
150      /// vector to a GPR.
151      MMX_MOVD2W,
152
153      /// PEXTRB - Extract an 8-bit value from a vector and zero extend it to
154      /// i32, corresponds to X86::PEXTRB.
155      PEXTRB,
156
157      /// PEXTRW - Extract a 16-bit value from a vector and zero extend it to
158      /// i32, corresponds to X86::PEXTRW.
159      PEXTRW,
160
161      /// INSERTPS - Insert any element of a 4 x float vector into any element
162      /// of a destination 4 x floatvector.
163      INSERTPS,
164
165      /// PINSRB - Insert the lower 8-bits of a 32-bit value to a vector,
166      /// corresponds to X86::PINSRB.
167      PINSRB,
168
169      /// PINSRW - Insert the lower 16-bits of a 32-bit value to a vector,
170      /// corresponds to X86::PINSRW.
171      PINSRW, MMX_PINSRW,
172
173      /// PSHUFB - Shuffle 16 8-bit values within a vector.
174      PSHUFB,
175
176      /// ANDNP - Bitwise Logical AND NOT of Packed FP values.
177      ANDNP,
178
179      /// PSIGN - Copy integer sign.
180      PSIGN,
181
182      /// BLENDV - Blend where the selector is a register.
183      BLENDV,
184
185      /// BLENDI - Blend where the selector is an immediate.
186      BLENDI,
187
188      // SUBUS - Integer sub with unsigned saturation.
189      SUBUS,
190
191      /// HADD - Integer horizontal add.
192      HADD,
193
194      /// HSUB - Integer horizontal sub.
195      HSUB,
196
197      /// FHADD - Floating point horizontal add.
198      FHADD,
199
200      /// FHSUB - Floating point horizontal sub.
201      FHSUB,
202
203      /// UMAX, UMIN - Unsigned integer max and min.
204      UMAX, UMIN,
205
206      /// SMAX, SMIN - Signed integer max and min.
207      SMAX, SMIN,
208
209      /// FMAX, FMIN - Floating point max and min.
210      ///
211      FMAX, FMIN,
212
213      /// FMAXC, FMINC - Commutative FMIN and FMAX.
214      FMAXC, FMINC,
215
216      /// FRSQRT, FRCP - Floating point reciprocal-sqrt and reciprocal
217      /// approximation.  Note that these typically require refinement
218      /// in order to obtain suitable precision.
219      FRSQRT, FRCP,
220
221      // TLSADDR - Thread Local Storage.
222      TLSADDR,
223
224      // TLSBASEADDR - Thread Local Storage. A call to get the start address
225      // of the TLS block for the current module.
226      TLSBASEADDR,
227
228      // TLSCALL - Thread Local Storage.  When calling to an OS provided
229      // thunk at the address from an earlier relocation.
230      TLSCALL,
231
232      // EH_RETURN - Exception Handling helpers.
233      EH_RETURN,
234
235      // EH_SJLJ_SETJMP - SjLj exception handling setjmp.
236      EH_SJLJ_SETJMP,
237
238      // EH_SJLJ_LONGJMP - SjLj exception handling longjmp.
239      EH_SJLJ_LONGJMP,
240
241      /// TC_RETURN - Tail call return. See X86TargetLowering::LowerCall for
242      /// the list of operands.
243      TC_RETURN,
244
245      // VZEXT_MOVL - Vector move low and zero extend.
246      VZEXT_MOVL,
247
248      // VSEXT_MOVL - Vector move low and sign extend.
249      VSEXT_MOVL,
250
251      // VZEXT - Vector integer zero-extend.
252      VZEXT,
253
254      // VSEXT - Vector integer signed-extend.
255      VSEXT,
256
257      // VFPEXT - Vector FP extend.
258      VFPEXT,
259
260      // VFPROUND - Vector FP round.
261      VFPROUND,
262
263      // VSHL, VSRL - 128-bit vector logical left / right shift
264      VSHLDQ, VSRLDQ,
265
266      // VSHL, VSRL, VSRA - Vector shift elements
267      VSHL, VSRL, VSRA,
268
269      // VSHLI, VSRLI, VSRAI - Vector shift elements by immediate
270      VSHLI, VSRLI, VSRAI,
271
272      // CMPP - Vector packed double/float comparison.
273      CMPP,
274
275      // PCMP* - Vector integer comparisons.
276      PCMPEQ, PCMPGT,
277
278      // ADD, SUB, SMUL, etc. - Arithmetic operations with FLAGS results.
279      ADD, SUB, ADC, SBB, SMUL,
280      INC, DEC, OR, XOR, AND,
281
282      BLSI,   // BLSI - Extract lowest set isolated bit
283      BLSMSK, // BLSMSK - Get mask up to lowest set bit
284      BLSR,   // BLSR - Reset lowest set bit
285
286      UMUL, // LOW, HI, FLAGS = umul LHS, RHS
287
288      // MUL_IMM - X86 specific multiply by immediate.
289      MUL_IMM,
290
291      // PTEST - Vector bitwise comparisons
292      PTEST,
293
294      // TESTP - Vector packed fp sign bitwise comparisons
295      TESTP,
296
297      // OR/AND test for masks
298      KORTEST,
299      KTEST,
300
301      // Several flavors of instructions with vector shuffle behaviors.
302      PALIGNR,
303      PSHUFD,
304      PSHUFHW,
305      PSHUFLW,
306      SHUFP,
307      MOVDDUP,
308      MOVSHDUP,
309      MOVSLDUP,
310      MOVLHPS,
311      MOVLHPD,
312      MOVHLPS,
313      MOVLPS,
314      MOVLPD,
315      MOVSD,
316      MOVSS,
317      UNPCKL,
318      UNPCKH,
319      VPERMILP,
320      VPERMV,
321      VPERMI,
322      VPERM2X128,
323      VBROADCAST,
324      // masked broadcast
325      VBROADCASTM,
326
327      // PMULUDQ - Vector multiply packed unsigned doubleword integers
328      PMULUDQ,
329
330      // FMA nodes
331      FMADD,
332      FNMADD,
333      FMSUB,
334      FNMSUB,
335      FMADDSUB,
336      FMSUBADD,
337
338      // VASTART_SAVE_XMM_REGS - Save xmm argument registers to the stack,
339      // according to %al. An operator is needed so that this can be expanded
340      // with control flow.
341      VASTART_SAVE_XMM_REGS,
342
343      // WIN_ALLOCA - Windows's _chkstk call to do stack probing.
344      WIN_ALLOCA,
345
346      // SEG_ALLOCA - For allocating variable amounts of stack space when using
347      // segmented stacks. Check if the current stacklet has enough space, and
348      // falls back to heap allocation if not.
349      SEG_ALLOCA,
350
351      // WIN_FTOL - Windows's _ftol2 runtime routine to do fptoui.
352      WIN_FTOL,
353
354      // Memory barrier
355      MEMBARRIER,
356      MFENCE,
357      SFENCE,
358      LFENCE,
359
360      // FNSTSW16r - Store FP status word into i16 register.
361      FNSTSW16r,
362
363      // SAHF - Store contents of %ah into %eflags.
364      SAHF,
365
366      // RDRAND - Get a random integer and indicate whether it is valid in CF.
367      RDRAND,
368
369      // RDSEED - Get a NIST SP800-90B & C compliant random integer and
370      // indicate whether it is valid in CF.
371      RDSEED,
372
373      // PCMP*STRI
374      PCMPISTRI,
375      PCMPESTRI,
376
377      // XTEST - Test if in transactional execution.
378      XTEST,
379
380      // ATOMADD64_DAG, ATOMSUB64_DAG, ATOMOR64_DAG, ATOMAND64_DAG,
381      // ATOMXOR64_DAG, ATOMNAND64_DAG, ATOMSWAP64_DAG -
382      // Atomic 64-bit binary operations.
383      ATOMADD64_DAG = ISD::FIRST_TARGET_MEMORY_OPCODE,
384      ATOMSUB64_DAG,
385      ATOMOR64_DAG,
386      ATOMXOR64_DAG,
387      ATOMAND64_DAG,
388      ATOMNAND64_DAG,
389      ATOMMAX64_DAG,
390      ATOMMIN64_DAG,
391      ATOMUMAX64_DAG,
392      ATOMUMIN64_DAG,
393      ATOMSWAP64_DAG,
394
395      // LCMPXCHG_DAG, LCMPXCHG8_DAG, LCMPXCHG16_DAG - Compare and swap.
396      LCMPXCHG_DAG,
397      LCMPXCHG8_DAG,
398      LCMPXCHG16_DAG,
399
400      // VZEXT_LOAD - Load, scalar_to_vector, and zero extend.
401      VZEXT_LOAD,
402
403      // FNSTCW16m - Store FP control world into i16 memory.
404      FNSTCW16m,
405
406      /// FP_TO_INT*_IN_MEM - This instruction implements FP_TO_SINT with the
407      /// integer destination in memory and a FP reg source.  This corresponds
408      /// to the X86::FIST*m instructions and the rounding mode change stuff. It
409      /// has two inputs (token chain and address) and two outputs (int value
410      /// and token chain).
411      FP_TO_INT16_IN_MEM,
412      FP_TO_INT32_IN_MEM,
413      FP_TO_INT64_IN_MEM,
414
415      /// FILD, FILD_FLAG - This instruction implements SINT_TO_FP with the
416      /// integer source in memory and FP reg result.  This corresponds to the
417      /// X86::FILD*m instructions. It has three inputs (token chain, address,
418      /// and source type) and two outputs (FP value and token chain). FILD_FLAG
419      /// also produces a flag).
420      FILD,
421      FILD_FLAG,
422
423      /// FLD - This instruction implements an extending load to FP stack slots.
424      /// This corresponds to the X86::FLD32m / X86::FLD64m. It takes a chain
425      /// operand, ptr to load from, and a ValueType node indicating the type
426      /// to load to.
427      FLD,
428
429      /// FST - This instruction implements a truncating store to FP stack
430      /// slots. This corresponds to the X86::FST32m / X86::FST64m. It takes a
431      /// chain operand, value to store, address, and a ValueType to store it
432      /// as.
433      FST,
434
435      /// VAARG_64 - This instruction grabs the address of the next argument
436      /// from a va_list. (reads and modifies the va_list in memory)
437      VAARG_64
438
439      // WARNING: Do not add anything in the end unless you want the node to
440      // have memop! In fact, starting from ATOMADD64_DAG all opcodes will be
441      // thought as target memory ops!
442    };
443  }
444
445  /// Define some predicates that are used for node matching.
446  namespace X86 {
447    /// isVEXTRACT128Index - Return true if the specified
448    /// EXTRACT_SUBVECTOR operand specifies a vector extract that is
449    /// suitable for input to VEXTRACTF128, VEXTRACTI128 instructions.
450    bool isVEXTRACT128Index(SDNode *N);
451
452    /// isVINSERT128Index - Return true if the specified
453    /// INSERT_SUBVECTOR operand specifies a subvector insert that is
454    /// suitable for input to VINSERTF128, VINSERTI128 instructions.
455    bool isVINSERT128Index(SDNode *N);
456
457    /// isVEXTRACT256Index - Return true if the specified
458    /// EXTRACT_SUBVECTOR operand specifies a vector extract that is
459    /// suitable for input to VEXTRACTF64X4, VEXTRACTI64X4 instructions.
460    bool isVEXTRACT256Index(SDNode *N);
461
462    /// isVINSERT256Index - Return true if the specified
463    /// INSERT_SUBVECTOR operand specifies a subvector insert that is
464    /// suitable for input to VINSERTF64X4, VINSERTI64X4 instructions.
465    bool isVINSERT256Index(SDNode *N);
466
467    /// getExtractVEXTRACT128Immediate - Return the appropriate
468    /// immediate to extract the specified EXTRACT_SUBVECTOR index
469    /// with VEXTRACTF128, VEXTRACTI128 instructions.
470    unsigned getExtractVEXTRACT128Immediate(SDNode *N);
471
472    /// getInsertVINSERT128Immediate - Return the appropriate
473    /// immediate to insert at the specified INSERT_SUBVECTOR index
474    /// with VINSERTF128, VINSERT128 instructions.
475    unsigned getInsertVINSERT128Immediate(SDNode *N);
476
477    /// getExtractVEXTRACT256Immediate - Return the appropriate
478    /// immediate to extract the specified EXTRACT_SUBVECTOR index
479    /// with VEXTRACTF64X4, VEXTRACTI64x4 instructions.
480    unsigned getExtractVEXTRACT256Immediate(SDNode *N);
481
482    /// getInsertVINSERT256Immediate - Return the appropriate
483    /// immediate to insert at the specified INSERT_SUBVECTOR index
484    /// with VINSERTF64x4, VINSERTI64x4 instructions.
485    unsigned getInsertVINSERT256Immediate(SDNode *N);
486
487    /// isZeroNode - Returns true if Elt is a constant zero or a floating point
488    /// constant +0.0.
489    bool isZeroNode(SDValue Elt);
490
491    /// isOffsetSuitableForCodeModel - Returns true of the given offset can be
492    /// fit into displacement field of the instruction.
493    bool isOffsetSuitableForCodeModel(int64_t Offset, CodeModel::Model M,
494                                      bool hasSymbolicDisplacement = true);
495
496
497    /// isCalleePop - Determines whether the callee is required to pop its
498    /// own arguments. Callee pop is necessary to support tail calls.
499    bool isCalleePop(CallingConv::ID CallingConv,
500                     bool is64Bit, bool IsVarArg, bool TailCallOpt);
501  }
502
503  //===--------------------------------------------------------------------===//
504  //  X86TargetLowering - X86 Implementation of the TargetLowering interface
505  class X86TargetLowering : public TargetLowering {
506  public:
507    explicit X86TargetLowering(X86TargetMachine &TM);
508
509    virtual unsigned getJumpTableEncoding() const;
510
511    virtual MVT getScalarShiftAmountTy(EVT LHSTy) const { return MVT::i8; }
512
513    virtual const MCExpr *
514    LowerCustomJumpTableEntry(const MachineJumpTableInfo *MJTI,
515                              const MachineBasicBlock *MBB, unsigned uid,
516                              MCContext &Ctx) const;
517
518    /// getPICJumpTableRelocaBase - Returns relocation base for the given PIC
519    /// jumptable.
520    virtual SDValue getPICJumpTableRelocBase(SDValue Table,
521                                             SelectionDAG &DAG) const;
522    virtual const MCExpr *
523    getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
524                                 unsigned JTI, MCContext &Ctx) const;
525
526    /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
527    /// function arguments in the caller parameter area. For X86, aggregates
528    /// that contains are placed at 16-byte boundaries while the rest are at
529    /// 4-byte boundaries.
530    virtual unsigned getByValTypeAlignment(Type *Ty) const;
531
532    /// getOptimalMemOpType - Returns the target specific optimal type for load
533    /// and store operations as a result of memset, memcpy, and memmove
534    /// lowering. If DstAlign is zero that means it's safe to destination
535    /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
536    /// means there isn't a need to check it against alignment requirement,
537    /// probably because the source does not need to be loaded. If 'IsMemset' is
538    /// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
539    /// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
540    /// source is constant so it does not need to be loaded.
541    /// It returns EVT::Other if the type should be determined using generic
542    /// target-independent logic.
543    virtual EVT
544    getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
545                        bool IsMemset, bool ZeroMemset, bool MemcpyStrSrc,
546                        MachineFunction &MF) const;
547
548    /// isSafeMemOpType - Returns true if it's safe to use load / store of the
549    /// specified type to expand memcpy / memset inline. This is mostly true
550    /// for all types except for some special cases. For example, on X86
551    /// targets without SSE2 f64 load / store are done with fldl / fstpl which
552    /// also does type conversion. Note the specified type doesn't have to be
553    /// legal as the hook is used before type legalization.
554    virtual bool isSafeMemOpType(MVT VT) const;
555
556    /// allowsUnalignedMemoryAccesses - Returns true if the target allows
557    /// unaligned memory accesses. of the specified type. Returns whether it
558    /// is "fast" by reference in the second argument.
559    virtual bool allowsUnalignedMemoryAccesses(EVT VT, bool *Fast) const;
560
561    /// LowerOperation - Provide custom lowering hooks for some operations.
562    ///
563    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
564
565    /// ReplaceNodeResults - Replace the results of node with an illegal result
566    /// type with new values built out of custom code.
567    ///
568    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
569                                    SelectionDAG &DAG) const;
570
571
572    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
573
574    /// isTypeDesirableForOp - Return true if the target has native support for
575    /// the specified value type and it is 'desirable' to use the type for the
576    /// given node type. e.g. On x86 i16 is legal, but undesirable since i16
577    /// instruction encodings are longer and some i16 instructions are slow.
578    virtual bool isTypeDesirableForOp(unsigned Opc, EVT VT) const;
579
580    /// isTypeDesirable - Return true if the target has native support for the
581    /// specified value type and it is 'desirable' to use the type. e.g. On x86
582    /// i16 is legal, but undesirable since i16 instruction encodings are longer
583    /// and some i16 instructions are slow.
584    virtual bool IsDesirableToPromoteOp(SDValue Op, EVT &PVT) const;
585
586    virtual MachineBasicBlock *
587      EmitInstrWithCustomInserter(MachineInstr *MI,
588                                  MachineBasicBlock *MBB) const;
589
590
591    /// getTargetNodeName - This method returns the name of a target specific
592    /// DAG node.
593    virtual const char *getTargetNodeName(unsigned Opcode) const;
594
595    /// getSetCCResultType - Return the value type to use for ISD::SETCC.
596    virtual EVT getSetCCResultType(LLVMContext &Context, EVT VT) const;
597
598    /// computeMaskedBitsForTargetNode - Determine which of the bits specified
599    /// in Mask are known to be either zero or one and return them in the
600    /// KnownZero/KnownOne bitsets.
601    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
602                                                APInt &KnownZero,
603                                                APInt &KnownOne,
604                                                const SelectionDAG &DAG,
605                                                unsigned Depth = 0) const;
606
607    // ComputeNumSignBitsForTargetNode - Determine the number of bits in the
608    // operation that are sign bits.
609    virtual unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
610                                                     unsigned Depth) const;
611
612    virtual bool
613    isGAPlusOffset(SDNode *N, const GlobalValue* &GA, int64_t &Offset) const;
614
615    SDValue getReturnAddressFrameIndex(SelectionDAG &DAG) const;
616
617    virtual bool ExpandInlineAsm(CallInst *CI) const;
618
619    ConstraintType getConstraintType(const std::string &Constraint) const;
620
621    /// Examine constraint string and operand type and determine a weight value.
622    /// The operand object must already have been set up with the operand type.
623    virtual ConstraintWeight getSingleConstraintMatchWeight(
624      AsmOperandInfo &info, const char *constraint) const;
625
626    virtual const char *LowerXConstraint(EVT ConstraintVT) const;
627
628    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
629    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
630    /// true it means one of the asm constraint of the inline asm instruction
631    /// being processed is 'm'.
632    virtual void LowerAsmOperandForConstraint(SDValue Op,
633                                              std::string &Constraint,
634                                              std::vector<SDValue> &Ops,
635                                              SelectionDAG &DAG) const;
636
637    /// getRegForInlineAsmConstraint - Given a physical register constraint
638    /// (e.g. {edx}), return the register number and the register class for the
639    /// register.  This should only be used for C_Register constraints.  On
640    /// error, this returns a register number of 0.
641    std::pair<unsigned, const TargetRegisterClass*>
642      getRegForInlineAsmConstraint(const std::string &Constraint,
643                                   MVT VT) const;
644
645    /// isLegalAddressingMode - Return true if the addressing mode represented
646    /// by AM is legal for this target, for a load/store of the specified type.
647    virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty)const;
648
649    /// isLegalICmpImmediate - Return true if the specified immediate is legal
650    /// icmp immediate, that is the target has icmp instructions which can
651    /// compare a register against the immediate without having to materialize
652    /// the immediate into a register.
653    virtual bool isLegalICmpImmediate(int64_t Imm) const;
654
655    /// isLegalAddImmediate - Return true if the specified immediate is legal
656    /// add immediate, that is the target has add instructions which can
657    /// add a register and the immediate without having to materialize
658    /// the immediate into a register.
659    virtual bool isLegalAddImmediate(int64_t Imm) const;
660
661    /// isTruncateFree - Return true if it's free to truncate a value of
662    /// type Ty1 to type Ty2. e.g. On x86 it's free to truncate a i32 value in
663    /// register EAX to i16 by referencing its sub-register AX.
664    virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const;
665    virtual bool isTruncateFree(EVT VT1, EVT VT2) const;
666
667    virtual bool allowTruncateForTailCall(Type *Ty1, Type *Ty2) const;
668
669    /// isZExtFree - Return true if any actual instruction that defines a
670    /// value of type Ty1 implicit zero-extends the value to Ty2 in the result
671    /// register. This does not necessarily include registers defined in
672    /// unknown ways, such as incoming arguments, or copies from unknown
673    /// virtual registers. Also, if isTruncateFree(Ty2, Ty1) is true, this
674    /// does not necessarily apply to truncate instructions. e.g. on x86-64,
675    /// all instructions that define 32-bit values implicit zero-extend the
676    /// result out to 64 bits.
677    virtual bool isZExtFree(Type *Ty1, Type *Ty2) const;
678    virtual bool isZExtFree(EVT VT1, EVT VT2) const;
679    virtual bool isZExtFree(SDValue Val, EVT VT2) const;
680
681    /// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
682    /// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
683    /// expanded to FMAs when this method returns true, otherwise fmuladd is
684    /// expanded to fmul + fadd.
685    virtual bool isFMAFasterThanFMulAndFAdd(EVT VT) const;
686
687    /// isNarrowingProfitable - Return true if it's profitable to narrow
688    /// operations of type VT1 to VT2. e.g. on x86, it's profitable to narrow
689    /// from i32 to i8 but not from i32 to i16.
690    virtual bool isNarrowingProfitable(EVT VT1, EVT VT2) const;
691
692    /// isFPImmLegal - Returns true if the target can instruction select the
693    /// specified FP immediate natively. If false, the legalizer will
694    /// materialize the FP immediate as a load from a constant pool.
695    virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const;
696
697    /// isShuffleMaskLegal - Targets can use this to indicate that they only
698    /// support *some* VECTOR_SHUFFLE operations, those with specific masks.
699    /// By default, if a target supports the VECTOR_SHUFFLE node, all mask
700    /// values are assumed to be legal.
701    virtual bool isShuffleMaskLegal(const SmallVectorImpl<int> &Mask,
702                                    EVT VT) const;
703
704    /// isVectorClearMaskLegal - Similar to isShuffleMaskLegal. This is
705    /// used by Targets can use this to indicate if there is a suitable
706    /// VECTOR_SHUFFLE that can be used to replace a VAND with a constant
707    /// pool entry.
708    virtual bool isVectorClearMaskLegal(const SmallVectorImpl<int> &Mask,
709                                        EVT VT) const;
710
711    /// ShouldShrinkFPConstant - If true, then instruction selection should
712    /// seek to shrink the FP constant of the specified type to a smaller type
713    /// in order to save space and / or reduce runtime.
714    virtual bool ShouldShrinkFPConstant(EVT VT) const {
715      // Don't shrink FP constpool if SSE2 is available since cvtss2sd is more
716      // expensive than a straight movsd. On the other hand, it's important to
717      // shrink long double fp constant since fldt is very slow.
718      return !X86ScalarSSEf64 || VT == MVT::f80;
719    }
720
721    const X86Subtarget* getSubtarget() const {
722      return Subtarget;
723    }
724
725    /// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is
726    /// computed in an SSE register, not on the X87 floating point stack.
727    bool isScalarFPTypeInSSEReg(EVT VT) const {
728      return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2
729      (VT == MVT::f32 && X86ScalarSSEf32);   // f32 is when SSE1
730    }
731
732    /// isTargetFTOL - Return true if the target uses the MSVC _ftol2 routine
733    /// for fptoui.
734    bool isTargetFTOL() const {
735      return Subtarget->isTargetWindows() && !Subtarget->is64Bit();
736    }
737
738    /// isIntegerTypeFTOL - Return true if the MSVC _ftol2 routine should be
739    /// used for fptoui to the given type.
740    bool isIntegerTypeFTOL(EVT VT) const {
741      return isTargetFTOL() && VT == MVT::i64;
742    }
743
744    /// createFastISel - This method returns a target specific FastISel object,
745    /// or null if the target does not support "fast" ISel.
746    virtual FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
747                                     const TargetLibraryInfo *libInfo) const;
748
749    /// getStackCookieLocation - Return true if the target stores stack
750    /// protector cookies at a fixed offset in some non-standard address
751    /// space, and populates the address space and offset as
752    /// appropriate.
753    virtual bool getStackCookieLocation(unsigned &AddressSpace, unsigned &Offset) const;
754
755    SDValue BuildFILD(SDValue Op, EVT SrcVT, SDValue Chain, SDValue StackSlot,
756                      SelectionDAG &DAG) const;
757
758    /// \brief Reset the operation actions based on target options.
759    virtual void resetOperationActions();
760
761  protected:
762    std::pair<const TargetRegisterClass*, uint8_t>
763    findRepresentativeClass(MVT VT) const;
764
765  private:
766    /// Subtarget - Keep a pointer to the X86Subtarget around so that we can
767    /// make the right decision when generating code for different targets.
768    const X86Subtarget *Subtarget;
769    const DataLayout *TD;
770
771    /// Used to store the TargetOptions so that we don't waste time resetting
772    /// the operation actions unless we have to.
773    TargetOptions TO;
774
775    /// X86ScalarSSEf32, X86ScalarSSEf64 - Select between SSE or x87
776    /// floating point ops.
777    /// When SSE is available, use it for f32 operations.
778    /// When SSE2 is available, use it for f64 operations.
779    bool X86ScalarSSEf32;
780    bool X86ScalarSSEf64;
781
782    /// LegalFPImmediates - A list of legal fp immediates.
783    std::vector<APFloat> LegalFPImmediates;
784
785    /// addLegalFPImmediate - Indicate that this x86 target can instruction
786    /// select the specified FP immediate natively.
787    void addLegalFPImmediate(const APFloat& Imm) {
788      LegalFPImmediates.push_back(Imm);
789    }
790
791    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
792                            CallingConv::ID CallConv, bool isVarArg,
793                            const SmallVectorImpl<ISD::InputArg> &Ins,
794                            SDLoc dl, SelectionDAG &DAG,
795                            SmallVectorImpl<SDValue> &InVals) const;
796    SDValue LowerMemArgument(SDValue Chain,
797                             CallingConv::ID CallConv,
798                             const SmallVectorImpl<ISD::InputArg> &ArgInfo,
799                             SDLoc dl, SelectionDAG &DAG,
800                             const CCValAssign &VA,  MachineFrameInfo *MFI,
801                              unsigned i) const;
802    SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
803                             SDLoc dl, SelectionDAG &DAG,
804                             const CCValAssign &VA,
805                             ISD::ArgFlagsTy Flags) const;
806
807    // Call lowering helpers.
808
809    /// IsEligibleForTailCallOptimization - Check whether the call is eligible
810    /// for tail call optimization. Targets which want to do tail call
811    /// optimization should implement this function.
812    bool IsEligibleForTailCallOptimization(SDValue Callee,
813                                           CallingConv::ID CalleeCC,
814                                           bool isVarArg,
815                                           bool isCalleeStructRet,
816                                           bool isCallerStructRet,
817                                           Type *RetTy,
818                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
819                                    const SmallVectorImpl<SDValue> &OutVals,
820                                    const SmallVectorImpl<ISD::InputArg> &Ins,
821                                           SelectionDAG& DAG) const;
822    bool IsCalleePop(bool isVarArg, CallingConv::ID CallConv) const;
823    SDValue EmitTailCallLoadRetAddr(SelectionDAG &DAG, SDValue &OutRetAddr,
824                                SDValue Chain, bool IsTailCall, bool Is64Bit,
825                                int FPDiff, SDLoc dl) const;
826
827    unsigned GetAlignedArgumentStackSize(unsigned StackSize,
828                                         SelectionDAG &DAG) const;
829
830    std::pair<SDValue,SDValue> FP_TO_INTHelper(SDValue Op, SelectionDAG &DAG,
831                                               bool isSigned,
832                                               bool isReplace) const;
833
834    SDValue LowerAsSplatVectorLoad(SDValue SrcOp, EVT VT, SDLoc dl,
835                                   SelectionDAG &DAG) const;
836    SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
837    SDValue LowerBUILD_VECTORvXi1(SDValue Op, SelectionDAG &DAG) const;
838    SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
839    SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
840    SDValue LowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
841    SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
842    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
843    SDValue LowerGlobalAddress(const GlobalValue *GV, SDLoc dl,
844                               int64_t Offset, SelectionDAG &DAG) const;
845    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
846    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
847    SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
848    SDValue LowerShiftParts(SDValue Op, SelectionDAG &DAG) const;
849    SDValue LowerBITCAST(SDValue op, SelectionDAG &DAG) const;
850    SDValue LowerSINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
851    SDValue LowerUINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
852    SDValue LowerUINT_TO_FP_i64(SDValue Op, SelectionDAG &DAG) const;
853    SDValue LowerUINT_TO_FP_i32(SDValue Op, SelectionDAG &DAG) const;
854    SDValue lowerUINT_TO_FP_vec(SDValue Op, SelectionDAG &DAG) const;
855    SDValue LowerTRUNCATE(SDValue Op, SelectionDAG &DAG) const;
856    SDValue LowerZERO_EXTEND(SDValue Op, SelectionDAG &DAG) const;
857    SDValue LowerZERO_EXTEND_AVX512(SDValue Op, SelectionDAG &DAG) const;
858    SDValue LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG) const;
859    SDValue LowerSIGN_EXTEND_AVX512(SDValue Op, SelectionDAG &DAG) const;
860    SDValue LowerANY_EXTEND(SDValue Op, SelectionDAG &DAG) const;
861    SDValue LowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const;
862    SDValue LowerFP_TO_UINT(SDValue Op, SelectionDAG &DAG) const;
863    SDValue LowerFABS(SDValue Op, SelectionDAG &DAG) const;
864    SDValue LowerFNEG(SDValue Op, SelectionDAG &DAG) const;
865    SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
866    SDValue LowerToBT(SDValue And, ISD::CondCode CC,
867                      SDLoc dl, SelectionDAG &DAG) const;
868    SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
869    SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
870    SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
871    SDValue LowerMEMSET(SDValue Op, SelectionDAG &DAG) const;
872    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
873    SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
874    SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
875    SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG) const;
876    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
877    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
878    SDValue LowerFRAME_TO_ARGS_OFFSET(SDValue Op, SelectionDAG &DAG) const;
879    SDValue LowerEH_RETURN(SDValue Op, SelectionDAG &DAG) const;
880    SDValue lowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
881    SDValue lowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
882    SDValue LowerINIT_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
883    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
884    SDValue LowerShift(SDValue Op, SelectionDAG &DAG) const;
885    SDValue LowerSDIV(SDValue Op, SelectionDAG &DAG) const;
886    SDValue LowerSIGN_EXTEND_INREG(SDValue Op, SelectionDAG &DAG) const;
887    SDValue LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const;
888
889    // Utility functions to help LowerVECTOR_SHUFFLE & LowerBUILD_VECTOR
890    SDValue LowerVectorBroadcast(SDValue Op, SelectionDAG &DAG) const;
891    SDValue NormalizeVectorShuffle(SDValue Op, SelectionDAG &DAG) const;
892    SDValue buildFromShuffleMostly(SDValue Op, SelectionDAG &DAG) const;
893
894    SDValue LowerVectorAllZeroTest(SDValue Op, SelectionDAG &DAG) const;
895
896    SDValue LowerVectorIntExtend(SDValue Op, SelectionDAG &DAG) const;
897
898    virtual SDValue
899      LowerFormalArguments(SDValue Chain,
900                           CallingConv::ID CallConv, bool isVarArg,
901                           const SmallVectorImpl<ISD::InputArg> &Ins,
902                           SDLoc dl, SelectionDAG &DAG,
903                           SmallVectorImpl<SDValue> &InVals) const;
904    virtual SDValue
905      LowerCall(CallLoweringInfo &CLI,
906                SmallVectorImpl<SDValue> &InVals) const;
907
908    virtual SDValue
909      LowerReturn(SDValue Chain,
910                  CallingConv::ID CallConv, bool isVarArg,
911                  const SmallVectorImpl<ISD::OutputArg> &Outs,
912                  const SmallVectorImpl<SDValue> &OutVals,
913                  SDLoc dl, SelectionDAG &DAG) const;
914
915    virtual bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const;
916
917    virtual bool mayBeEmittedAsTailCall(CallInst *CI) const;
918
919    virtual MVT
920    getTypeForExtArgOrReturn(MVT VT, ISD::NodeType ExtendKind) const;
921
922    virtual bool
923    CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
924                   bool isVarArg,
925                   const SmallVectorImpl<ISD::OutputArg> &Outs,
926                   LLVMContext &Context) const;
927
928    /// Utility function to emit atomic-load-arith operations (and, or, xor,
929    /// nand, max, min, umax, umin). It takes the corresponding instruction to
930    /// expand, the associated machine basic block, and the associated X86
931    /// opcodes for reg/reg.
932    MachineBasicBlock *EmitAtomicLoadArith(MachineInstr *MI,
933                                           MachineBasicBlock *MBB) const;
934
935    /// Utility function to emit atomic-load-arith operations (and, or, xor,
936    /// nand, add, sub, swap) for 64-bit operands on 32-bit target.
937    MachineBasicBlock *EmitAtomicLoadArith6432(MachineInstr *MI,
938                                               MachineBasicBlock *MBB) const;
939
940    // Utility function to emit the low-level va_arg code for X86-64.
941    MachineBasicBlock *EmitVAARG64WithCustomInserter(
942                       MachineInstr *MI,
943                       MachineBasicBlock *MBB) const;
944
945    /// Utility function to emit the xmm reg save portion of va_start.
946    MachineBasicBlock *EmitVAStartSaveXMMRegsWithCustomInserter(
947                                                   MachineInstr *BInstr,
948                                                   MachineBasicBlock *BB) const;
949
950    MachineBasicBlock *EmitLoweredSelect(MachineInstr *I,
951                                         MachineBasicBlock *BB) const;
952
953    MachineBasicBlock *EmitLoweredWinAlloca(MachineInstr *MI,
954                                              MachineBasicBlock *BB) const;
955
956    MachineBasicBlock *EmitLoweredSegAlloca(MachineInstr *MI,
957                                            MachineBasicBlock *BB,
958                                            bool Is64Bit) const;
959
960    MachineBasicBlock *EmitLoweredTLSCall(MachineInstr *MI,
961                                          MachineBasicBlock *BB) const;
962
963    MachineBasicBlock *emitLoweredTLSAddr(MachineInstr *MI,
964                                          MachineBasicBlock *BB) const;
965
966    MachineBasicBlock *emitEHSjLjSetJmp(MachineInstr *MI,
967                                        MachineBasicBlock *MBB) const;
968
969    MachineBasicBlock *emitEHSjLjLongJmp(MachineInstr *MI,
970                                         MachineBasicBlock *MBB) const;
971
972    /// Emit nodes that will be selected as "test Op0,Op0", or something
973    /// equivalent, for use with the given x86 condition code.
974    SDValue EmitTest(SDValue Op0, unsigned X86CC, SelectionDAG &DAG) const;
975
976    /// Emit nodes that will be selected as "cmp Op0,Op1", or something
977    /// equivalent, for use with the given x86 condition code.
978    SDValue EmitCmp(SDValue Op0, SDValue Op1, unsigned X86CC,
979                    SelectionDAG &DAG) const;
980
981    /// Convert a comparison if required by the subtarget.
982    SDValue ConvertCmpIfNecessary(SDValue Cmp, SelectionDAG &DAG) const;
983  };
984
985  namespace X86 {
986    FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
987                             const TargetLibraryInfo *libInfo);
988  }
989}
990
991#endif    // X86ISELLOWERING_H
992