1 //===-- X86ISelLowering.h - X86 DAG Lowering Interface ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the interfaces that X86 uses to lower LLVM code into a
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_LIB_TARGET_X86_X86ISELLOWERING_H
16 #define LLVM_LIB_TARGET_X86_X86ISELLOWERING_H
18 #include "llvm/CodeGen/CallingConvLower.h"
19 #include "llvm/CodeGen/SelectionDAG.h"
20 #include "llvm/Target/TargetLowering.h"
21 #include "llvm/Target/TargetOptions.h"
25 class X86TargetMachine;
28 // X86 Specific DAG Nodes
29 enum NodeType : unsigned {
30 // Start the numbering where the builtin ops leave off.
31 FIRST_NUMBER = ISD::BUILTIN_OP_END,
38 /// Double shift instructions. These correspond to
39 /// X86::SHLDxx and X86::SHRDxx instructions.
43 /// Bitwise logical AND of floating point values. This corresponds
44 /// to X86::ANDPS or X86::ANDPD.
47 /// Bitwise logical OR of floating point values. This corresponds
48 /// to X86::ORPS or X86::ORPD.
51 /// Bitwise logical XOR of floating point values. This corresponds
52 /// to X86::XORPS or X86::XORPD.
55 /// Bitwise logical ANDNOT of floating point values. This
56 /// corresponds to X86::ANDNPS or X86::ANDNPD.
59 /// These operations represent an abstract X86 call
60 /// instruction, which includes a bunch of information. In particular the
61 /// operands of these node are:
63 /// #0 - The incoming token chain
65 /// #2 - The number of arg bytes the caller pushes on the stack.
66 /// #3 - The number of arg bytes the callee pops off the stack.
67 /// #4 - The value to pass in AL/AX/EAX (optional)
68 /// #5 - The value to pass in DL/DX/EDX (optional)
70 /// The result values of these nodes are:
72 /// #0 - The outgoing token chain
73 /// #1 - The first register result value (optional)
74 /// #2 - The second register result value (optional)
78 /// This operation implements the lowering for readcyclecounter
81 /// X86 Read Time-Stamp Counter and Processor ID.
84 /// X86 Read Performance Monitoring Counters.
87 /// X86 compare and logical compare instructions.
90 /// X86 bit-test instructions.
93 /// X86 SetCC. Operand 0 is condition code, and operand 1 is the EFLAGS
94 /// operand, usually produced by a CMP instruction.
100 // Same as SETCC except it's materialized with a sbb and the value is all
101 // one's or all zero's.
102 SETCC_CARRY, // R = carry_bit ? ~0 : 0
104 /// X86 FP SETCC, implemented with CMP{cc}SS/CMP{cc}SD.
105 /// Operands are two FP values to compare; result is a mask of
106 /// 0s or 1s. Generally DTRT for C/C++ with NaNs.
109 /// X86 MOVMSK{pd|ps}, extracts sign bits of two or four FP values,
110 /// result in an integer GPR. Needs masking for scalar result.
113 /// X86 conditional moves. Operand 0 and operand 1 are the two values
114 /// to select from. Operand 2 is the condition code, and operand 3 is the
115 /// flag operand produced by a CMP or TEST instruction. It also writes a
119 /// X86 conditional branches. Operand 0 is the chain operand, operand 1
120 /// is the block to branch if condition is true, operand 2 is the
121 /// condition code, and operand 3 is the flag operand produced by a CMP
122 /// or TEST instruction.
125 /// Return with a flag operand. Operand 0 is the chain operand, operand
126 /// 1 is the number of bytes of stack to pop.
129 /// Repeat fill, corresponds to X86::REP_STOSx.
132 /// Repeat move, corresponds to X86::REP_MOVSx.
135 /// On Darwin, this node represents the result of the popl
136 /// at function entry, used for PIC code.
139 /// A wrapper node for TargetConstantPool,
140 /// TargetExternalSymbol, and TargetGlobalAddress.
143 /// Special wrapper used under X86-64 PIC mode for RIP
144 /// relative displacements.
147 /// Copies a 64-bit value from the low word of an XMM vector
148 /// to an MMX vector. If you think this is too close to the previous
149 /// mnemonic, so do I; blame Intel.
152 /// Copies a 32-bit value from the low word of a MMX
156 /// Copies a GPR into the low 32-bit word of a MMX vector
157 /// and zero out the high word.
160 /// Extract an 8-bit value from a vector and zero extend it to
161 /// i32, corresponds to X86::PEXTRB.
164 /// Extract a 16-bit value from a vector and zero extend it to
165 /// i32, corresponds to X86::PEXTRW.
168 /// Insert any element of a 4 x float vector into any element
169 /// of a destination 4 x floatvector.
172 /// Insert the lower 8-bits of a 32-bit value to a vector,
173 /// corresponds to X86::PINSRB.
176 /// Insert the lower 16-bits of a 32-bit value to a vector,
177 /// corresponds to X86::PINSRW.
180 /// Shuffle 16 8-bit values within a vector.
183 /// Compute Sum of Absolute Differences.
185 /// Compute Double Block Packed Sum-Absolute-Differences
188 /// Bitwise Logical AND NOT of Packed FP values.
191 /// Copy integer sign.
194 /// Blend where the selector is an immediate.
197 /// Blend where the condition has been shrunk.
198 /// This is used to emphasize that the condition mask is
199 /// no more valid for generic VSELECT optimizations.
202 /// Combined add and sub on an FP vector.
205 // FP vector ops with rounding mode.
214 // FP vector get exponent
218 // Integer add/sub with unsigned saturation.
221 // Integer add/sub with signed saturation.
224 // Unsigned Integer average
226 /// Integer horizontal add.
229 /// Integer horizontal sub.
232 /// Floating point horizontal add.
235 /// Floating point horizontal sub.
238 // Integer absolute value
241 /// Floating point max and min.
244 /// Commutative FMIN and FMAX.
247 /// Floating point reciprocal-sqrt and reciprocal approximation.
248 /// Note that these typically require refinement
249 /// in order to obtain suitable precision.
252 // Thread Local Storage.
255 // Thread Local Storage. A call to get the start address
256 // of the TLS block for the current module.
259 // Thread Local Storage. When calling to an OS provided
260 // thunk at the address from an earlier relocation.
263 // Exception Handling helpers.
268 // SjLj exception handling setjmp.
271 // SjLj exception handling longjmp.
274 /// Tail call return. See X86TargetLowering::LowerCall for
275 /// the list of operands.
278 // Vector move to low scalar and zero higher vector elements.
281 // Vector integer zero-extend.
284 // Vector integer signed-extend.
287 // Vector integer truncate.
289 // Vector integer truncate with unsigned/signed saturation.
298 // Vector signed/unsigned integer to double.
301 // 128-bit vector logical left / right shift
304 // Vector shift elements
307 // Vector shift elements by immediate
310 // Vector packed double/float comparison.
313 // Vector integer comparisons.
315 // Vector integer comparisons, the result is in a mask vector.
318 /// Vector comparison generating mask bits for fp and
319 /// integer signed and unsigned data types.
322 // Vector comparison with rounding mode for FP values
325 // Arithmetic operations with FLAGS results.
326 ADD, SUB, ADC, SBB, SMUL,
327 INC, DEC, OR, XOR, AND,
329 BEXTR, // Bit field extract
331 UMUL, // LOW, HI, FLAGS = umul LHS, RHS
333 // 8-bit SMUL/UMUL - AX, FLAGS = smul8/umul8 AL, RHS
336 // 8-bit divrem that zero-extend the high result (AH).
340 // X86-specific multiply by immediate.
343 // Vector bitwise comparisons.
346 // Vector packed fp sign bitwise comparisons.
349 // Vector "test" in AVX-512, the result is in a mask vector.
353 // OR/AND test for masks
357 // Several flavors of instructions with vector shuffle behaviors.
362 // AVX512 inter-lane alignr
368 //Shuffle Packed Values at 128-bit granularity
389 //Fix Up Special Packed Float32/64 values
391 //Range Restriction Calculation For Packed Pairs of Float32/64 values
393 // Reduce - Perform Reduction Transformation on scalar\packed FP
395 // RndScale - Round FP Values To Include A Given Number Of Fraction Bits
397 // Broadcast scalar to vector
399 // Broadcast subvector to vector
401 // Insert/Extract vector element
405 /// SSE4A Extraction and Insertion.
408 // Vector multiply packed unsigned doubleword integers
410 // Vector multiply packed signed doubleword integers
412 // Vector Multiply Packed UnsignedIntegers with Round and Scale
414 // Multiply and Add Packed Integers
415 VPMADDUBSW, VPMADDWD,
423 // FMA with rounding mode
431 // Compress and expand
435 //Convert Unsigned/Integer to Scalar Floating-Point Value
440 // Vector float/double to signed/unsigned integer.
441 FP_TO_SINT_RND, FP_TO_UINT_RND,
442 // Save xmm argument registers to the stack, according to %al. An operator
443 // is needed so that this can be expanded with control flow.
444 VASTART_SAVE_XMM_REGS,
446 // Windows's _chkstk call to do stack probing.
449 // For allocating variable amounts of stack space when using
450 // segmented stacks. Check if the current stacklet has enough space, and
451 // falls back to heap allocation if not.
460 // Store FP status word into i16 register.
463 // Store contents of %ah into %eflags.
466 // Get a random integer and indicate whether it is valid in CF.
469 // Get a NIST SP800-90B & C compliant random integer and
470 // indicate whether it is valid in CF.
476 // Test if in transactional execution.
480 RSQRT28, RCP28, EXP2,
483 LCMPXCHG_DAG = ISD::FIRST_TARGET_MEMORY_OPCODE,
487 // Load, scalar_to_vector, and zero extend.
490 // Store FP control world into i16 memory.
493 /// This instruction implements FP_TO_SINT with the
494 /// integer destination in memory and a FP reg source. This corresponds
495 /// to the X86::FIST*m instructions and the rounding mode change stuff. It
496 /// has two inputs (token chain and address) and two outputs (int value
497 /// and token chain).
502 /// This instruction implements SINT_TO_FP with the
503 /// integer source in memory and FP reg result. This corresponds to the
504 /// X86::FILD*m instructions. It has three inputs (token chain, address,
505 /// and source type) and two outputs (FP value and token chain). FILD_FLAG
506 /// also produces a flag).
510 /// This instruction implements an extending load to FP stack slots.
511 /// This corresponds to the X86::FLD32m / X86::FLD64m. It takes a chain
512 /// operand, ptr to load from, and a ValueType node indicating the type
516 /// This instruction implements a truncating store to FP stack
517 /// slots. This corresponds to the X86::FST32m / X86::FST64m. It takes a
518 /// chain operand, value to store, address, and a ValueType to store it
522 /// This instruction grabs the address of the next argument
523 /// from a va_list. (reads and modifies the va_list in memory)
526 // WARNING: Do not add anything in the end unless you want the node to
527 // have memop! In fact, starting from ATOMADD64_DAG all opcodes will be
528 // thought as target memory ops!
532 /// Define some predicates that are used for node matching.
534 /// Return true if the specified
535 /// EXTRACT_SUBVECTOR operand specifies a vector extract that is
536 /// suitable for input to VEXTRACTF128, VEXTRACTI128 instructions.
537 bool isVEXTRACT128Index(SDNode *N);
539 /// Return true if the specified
540 /// INSERT_SUBVECTOR operand specifies a subvector insert that is
541 /// suitable for input to VINSERTF128, VINSERTI128 instructions.
542 bool isVINSERT128Index(SDNode *N);
544 /// Return true if the specified
545 /// EXTRACT_SUBVECTOR operand specifies a vector extract that is
546 /// suitable for input to VEXTRACTF64X4, VEXTRACTI64X4 instructions.
547 bool isVEXTRACT256Index(SDNode *N);
549 /// Return true if the specified
550 /// INSERT_SUBVECTOR operand specifies a subvector insert that is
551 /// suitable for input to VINSERTF64X4, VINSERTI64X4 instructions.
552 bool isVINSERT256Index(SDNode *N);
554 /// Return the appropriate
555 /// immediate to extract the specified EXTRACT_SUBVECTOR index
556 /// with VEXTRACTF128, VEXTRACTI128 instructions.
557 unsigned getExtractVEXTRACT128Immediate(SDNode *N);
559 /// Return the appropriate
560 /// immediate to insert at the specified INSERT_SUBVECTOR index
561 /// with VINSERTF128, VINSERT128 instructions.
562 unsigned getInsertVINSERT128Immediate(SDNode *N);
564 /// Return the appropriate
565 /// immediate to extract the specified EXTRACT_SUBVECTOR index
566 /// with VEXTRACTF64X4, VEXTRACTI64x4 instructions.
567 unsigned getExtractVEXTRACT256Immediate(SDNode *N);
569 /// Return the appropriate
570 /// immediate to insert at the specified INSERT_SUBVECTOR index
571 /// with VINSERTF64x4, VINSERTI64x4 instructions.
572 unsigned getInsertVINSERT256Immediate(SDNode *N);
574 /// Returns true if Elt is a constant zero or floating point constant +0.0.
575 bool isZeroNode(SDValue Elt);
577 /// Returns true of the given offset can be
578 /// fit into displacement field of the instruction.
579 bool isOffsetSuitableForCodeModel(int64_t Offset, CodeModel::Model M,
580 bool hasSymbolicDisplacement = true);
583 /// Determines whether the callee is required to pop its
584 /// own arguments. Callee pop is necessary to support tail calls.
585 bool isCalleePop(CallingConv::ID CallingConv,
586 bool is64Bit, bool IsVarArg, bool TailCallOpt);
588 /// AVX512 static rounding constants. These need to match the values in
590 enum STATIC_ROUNDING {
599 //===--------------------------------------------------------------------===//
600 // X86 Implementation of the TargetLowering interface
601 class X86TargetLowering final : public TargetLowering {
603 explicit X86TargetLowering(const X86TargetMachine &TM,
604 const X86Subtarget &STI);
606 unsigned getJumpTableEncoding() const override;
607 bool useSoftFloat() const override;
609 MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override {
614 LowerCustomJumpTableEntry(const MachineJumpTableInfo *MJTI,
615 const MachineBasicBlock *MBB, unsigned uid,
616 MCContext &Ctx) const override;
618 /// Returns relocation base for the given PIC jumptable.
619 SDValue getPICJumpTableRelocBase(SDValue Table,
620 SelectionDAG &DAG) const override;
622 getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
623 unsigned JTI, MCContext &Ctx) const override;
625 /// Return the desired alignment for ByVal aggregate
626 /// function arguments in the caller parameter area. For X86, aggregates
627 /// that contains are placed at 16-byte boundaries while the rest are at
628 /// 4-byte boundaries.
629 unsigned getByValTypeAlignment(Type *Ty,
630 const DataLayout &DL) const override;
632 /// Returns the target specific optimal type for load
633 /// and store operations as a result of memset, memcpy, and memmove
634 /// lowering. If DstAlign is zero that means it's safe to destination
635 /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
636 /// means there isn't a need to check it against alignment requirement,
637 /// probably because the source does not need to be loaded. If 'IsMemset' is
638 /// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
639 /// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
640 /// source is constant so it does not need to be loaded.
641 /// It returns EVT::Other if the type should be determined using generic
642 /// target-independent logic.
643 EVT getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
644 bool IsMemset, bool ZeroMemset, bool MemcpyStrSrc,
645 MachineFunction &MF) const override;
647 /// Returns true if it's safe to use load / store of the
648 /// specified type to expand memcpy / memset inline. This is mostly true
649 /// for all types except for some special cases. For example, on X86
650 /// targets without SSE2 f64 load / store are done with fldl / fstpl which
651 /// also does type conversion. Note the specified type doesn't have to be
652 /// legal as the hook is used before type legalization.
653 bool isSafeMemOpType(MVT VT) const override;
655 /// Returns true if the target allows unaligned memory accesses of the
656 /// specified type. Returns whether it is "fast" in the last argument.
657 bool allowsMisalignedMemoryAccesses(EVT VT, unsigned AS, unsigned Align,
658 bool *Fast) const override;
660 /// Provide custom lowering hooks for some operations.
662 SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
664 /// Replace the results of node with an illegal result
665 /// type with new values built out of custom code.
667 void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
668 SelectionDAG &DAG) const override;
671 SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
673 /// Return true if the target has native support for
674 /// the specified value type and it is 'desirable' to use the type for the
675 /// given node type. e.g. On x86 i16 is legal, but undesirable since i16
676 /// instruction encodings are longer and some i16 instructions are slow.
677 bool isTypeDesirableForOp(unsigned Opc, EVT VT) const override;
679 /// Return true if the target has native support for the
680 /// specified value type and it is 'desirable' to use the type. e.g. On x86
681 /// i16 is legal, but undesirable since i16 instruction encodings are longer
682 /// and some i16 instructions are slow.
683 bool IsDesirableToPromoteOp(SDValue Op, EVT &PVT) const override;
686 EmitInstrWithCustomInserter(MachineInstr *MI,
687 MachineBasicBlock *MBB) const override;
690 /// This method returns the name of a target specific DAG node.
691 const char *getTargetNodeName(unsigned Opcode) const override;
693 bool isCheapToSpeculateCttz() const override;
695 bool isCheapToSpeculateCtlz() const override;
697 /// Return the value type to use for ISD::SETCC.
698 EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
699 EVT VT) const override;
701 /// Determine which of the bits specified in Mask are known to be either
702 /// zero or one and return them in the KnownZero/KnownOne bitsets.
703 void computeKnownBitsForTargetNode(const SDValue Op,
706 const SelectionDAG &DAG,
707 unsigned Depth = 0) const override;
709 /// Determine the number of bits in the operation that are sign bits.
710 unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
711 const SelectionDAG &DAG,
712 unsigned Depth) const override;
714 bool isGAPlusOffset(SDNode *N, const GlobalValue* &GA,
715 int64_t &Offset) const override;
717 SDValue getReturnAddressFrameIndex(SelectionDAG &DAG) const;
719 bool ExpandInlineAsm(CallInst *CI) const override;
721 ConstraintType getConstraintType(StringRef Constraint) const override;
723 /// Examine constraint string and operand type and determine a weight value.
724 /// The operand object must already have been set up with the operand type.
726 getSingleConstraintMatchWeight(AsmOperandInfo &info,
727 const char *constraint) const override;
729 const char *LowerXConstraint(EVT ConstraintVT) const override;
731 /// Lower the specified operand into the Ops vector. If it is invalid, don't
732 /// add anything to Ops. If hasMemory is true it means one of the asm
733 /// constraint of the inline asm instruction being processed is 'm'.
734 void LowerAsmOperandForConstraint(SDValue Op,
735 std::string &Constraint,
736 std::vector<SDValue> &Ops,
737 SelectionDAG &DAG) const override;
740 getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
741 if (ConstraintCode == "i")
742 return InlineAsm::Constraint_i;
743 else if (ConstraintCode == "o")
744 return InlineAsm::Constraint_o;
745 else if (ConstraintCode == "v")
746 return InlineAsm::Constraint_v;
747 else if (ConstraintCode == "X")
748 return InlineAsm::Constraint_X;
749 return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
752 /// Given a physical register constraint
753 /// (e.g. {edx}), return the register number and the register class for the
754 /// register. This should only be used for C_Register constraints. On
755 /// error, this returns a register number of 0.
756 std::pair<unsigned, const TargetRegisterClass *>
757 getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
758 StringRef Constraint, MVT VT) const override;
760 /// Return true if the addressing mode represented
761 /// by AM is legal for this target, for a load/store of the specified type.
762 bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM,
763 Type *Ty, unsigned AS) const override;
765 /// Return true if the specified immediate is legal
766 /// icmp immediate, that is the target has icmp instructions which can
767 /// compare a register against the immediate without having to materialize
768 /// the immediate into a register.
769 bool isLegalICmpImmediate(int64_t Imm) const override;
771 /// Return true if the specified immediate is legal
772 /// add immediate, that is the target has add instructions which can
773 /// add a register and the immediate without having to materialize
774 /// the immediate into a register.
775 bool isLegalAddImmediate(int64_t Imm) const override;
777 /// \brief Return the cost of the scaling factor used in the addressing
778 /// mode represented by AM for this target, for a load/store
779 /// of the specified type.
780 /// If the AM is supported, the return value must be >= 0.
781 /// If the AM is not supported, it returns a negative value.
782 int getScalingFactorCost(const DataLayout &DL, const AddrMode &AM, Type *Ty,
783 unsigned AS) const override;
785 bool isVectorShiftByScalarCheap(Type *Ty) const override;
787 /// Return true if it's free to truncate a value of
788 /// type Ty1 to type Ty2. e.g. On x86 it's free to truncate a i32 value in
789 /// register EAX to i16 by referencing its sub-register AX.
790 bool isTruncateFree(Type *Ty1, Type *Ty2) const override;
791 bool isTruncateFree(EVT VT1, EVT VT2) const override;
793 bool allowTruncateForTailCall(Type *Ty1, Type *Ty2) const override;
795 /// Return true if any actual instruction that defines a
796 /// value of type Ty1 implicit zero-extends the value to Ty2 in the result
797 /// register. This does not necessarily include registers defined in
798 /// unknown ways, such as incoming arguments, or copies from unknown
799 /// virtual registers. Also, if isTruncateFree(Ty2, Ty1) is true, this
800 /// does not necessarily apply to truncate instructions. e.g. on x86-64,
801 /// all instructions that define 32-bit values implicit zero-extend the
802 /// result out to 64 bits.
803 bool isZExtFree(Type *Ty1, Type *Ty2) const override;
804 bool isZExtFree(EVT VT1, EVT VT2) const override;
805 bool isZExtFree(SDValue Val, EVT VT2) const override;
807 /// Return true if folding a vector load into ExtVal (a sign, zero, or any
808 /// extend node) is profitable.
809 bool isVectorLoadExtDesirable(SDValue) const override;
811 /// Return true if an FMA operation is faster than a pair of fmul and fadd
812 /// instructions. fmuladd intrinsics will be expanded to FMAs when this
813 /// method returns true, otherwise fmuladd is expanded to fmul + fadd.
814 bool isFMAFasterThanFMulAndFAdd(EVT VT) const override;
816 /// Return true if it's profitable to narrow
817 /// operations of type VT1 to VT2. e.g. on x86, it's profitable to narrow
818 /// from i32 to i8 but not from i32 to i16.
819 bool isNarrowingProfitable(EVT VT1, EVT VT2) const override;
821 /// Returns true if the target can instruction select the
822 /// specified FP immediate natively. If false, the legalizer will
823 /// materialize the FP immediate as a load from a constant pool.
824 bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
826 /// Targets can use this to indicate that they only support *some*
827 /// VECTOR_SHUFFLE operations, those with specific masks. By default, if a
828 /// target supports the VECTOR_SHUFFLE node, all mask values are assumed to
830 bool isShuffleMaskLegal(const SmallVectorImpl<int> &Mask,
831 EVT VT) const override;
833 /// Similar to isShuffleMaskLegal. This is used by Targets can use this to
834 /// indicate if there is a suitable VECTOR_SHUFFLE that can be used to
835 /// replace a VAND with a constant pool entry.
836 bool isVectorClearMaskLegal(const SmallVectorImpl<int> &Mask,
837 EVT VT) const override;
839 /// If true, then instruction selection should
840 /// seek to shrink the FP constant of the specified type to a smaller type
841 /// in order to save space and / or reduce runtime.
842 bool ShouldShrinkFPConstant(EVT VT) const override {
843 // Don't shrink FP constpool if SSE2 is available since cvtss2sd is more
844 // expensive than a straight movsd. On the other hand, it's important to
845 // shrink long double fp constant since fldt is very slow.
846 return !X86ScalarSSEf64 || VT == MVT::f80;
849 /// Return true if we believe it is correct and profitable to reduce the
850 /// load node to a smaller type.
851 bool shouldReduceLoadWidth(SDNode *Load, ISD::LoadExtType ExtTy,
852 EVT NewVT) const override;
854 /// Return true if the specified scalar FP type is computed in an SSE
855 /// register, not on the X87 floating point stack.
856 bool isScalarFPTypeInSSEReg(EVT VT) const {
857 return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2
858 (VT == MVT::f32 && X86ScalarSSEf32); // f32 is when SSE1
861 /// \brief Returns true if it is beneficial to convert a load of a constant
862 /// to just the constant itself.
863 bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
864 Type *Ty) const override;
866 /// Return true if EXTRACT_SUBVECTOR is cheap for this result type
868 bool isExtractSubvectorCheap(EVT ResVT, unsigned Index) const override;
870 /// Intel processors have a unified instruction and data cache
871 const char * getClearCacheBuiltinName() const override {
872 return nullptr; // nothing to do, move along.
875 unsigned getRegisterByName(const char* RegName, EVT VT,
876 SelectionDAG &DAG) const override;
878 /// This method returns a target specific FastISel object,
879 /// or null if the target does not support "fast" ISel.
880 FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
881 const TargetLibraryInfo *libInfo) const override;
883 /// Return true if the target stores stack protector cookies at a fixed
884 /// offset in some non-standard address space, and populates the address
885 /// space and offset as appropriate.
886 bool getStackCookieLocation(unsigned &AddressSpace,
887 unsigned &Offset) const override;
889 SDValue BuildFILD(SDValue Op, EVT SrcVT, SDValue Chain, SDValue StackSlot,
890 SelectionDAG &DAG) const;
892 bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override;
894 bool useLoadStackGuardNode() const override;
895 /// \brief Customize the preferred legalization strategy for certain types.
896 LegalizeTypeAction getPreferredVectorAction(EVT VT) const override;
898 bool isIntDivCheap(EVT VT, AttributeSet Attr) const override;
901 std::pair<const TargetRegisterClass *, uint8_t>
902 findRepresentativeClass(const TargetRegisterInfo *TRI,
903 MVT VT) const override;
906 /// Keep a pointer to the X86Subtarget around so that we can
907 /// make the right decision when generating code for different targets.
908 const X86Subtarget *Subtarget;
909 const DataLayout *TD;
911 /// Select between SSE or x87 floating point ops.
912 /// When SSE is available, use it for f32 operations.
913 /// When SSE2 is available, use it for f64 operations.
914 bool X86ScalarSSEf32;
915 bool X86ScalarSSEf64;
917 /// A list of legal FP immediates.
918 std::vector<APFloat> LegalFPImmediates;
920 /// Indicate that this x86 target can instruction
921 /// select the specified FP immediate natively.
922 void addLegalFPImmediate(const APFloat& Imm) {
923 LegalFPImmediates.push_back(Imm);
926 SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
927 CallingConv::ID CallConv, bool isVarArg,
928 const SmallVectorImpl<ISD::InputArg> &Ins,
929 SDLoc dl, SelectionDAG &DAG,
930 SmallVectorImpl<SDValue> &InVals) const;
931 SDValue LowerMemArgument(SDValue Chain,
932 CallingConv::ID CallConv,
933 const SmallVectorImpl<ISD::InputArg> &ArgInfo,
934 SDLoc dl, SelectionDAG &DAG,
935 const CCValAssign &VA, MachineFrameInfo *MFI,
937 SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
938 SDLoc dl, SelectionDAG &DAG,
939 const CCValAssign &VA,
940 ISD::ArgFlagsTy Flags) const;
942 // Call lowering helpers.
944 /// Check whether the call is eligible for tail call optimization. Targets
945 /// that want to do tail call optimization should implement this function.
946 bool IsEligibleForTailCallOptimization(SDValue Callee,
947 CallingConv::ID CalleeCC,
949 bool isCalleeStructRet,
950 bool isCallerStructRet,
952 const SmallVectorImpl<ISD::OutputArg> &Outs,
953 const SmallVectorImpl<SDValue> &OutVals,
954 const SmallVectorImpl<ISD::InputArg> &Ins,
955 SelectionDAG& DAG) const;
956 bool IsCalleePop(bool isVarArg, CallingConv::ID CallConv) const;
957 SDValue EmitTailCallLoadRetAddr(SelectionDAG &DAG, SDValue &OutRetAddr,
958 SDValue Chain, bool IsTailCall, bool Is64Bit,
959 int FPDiff, SDLoc dl) const;
961 unsigned GetAlignedArgumentStackSize(unsigned StackSize,
962 SelectionDAG &DAG) const;
964 std::pair<SDValue,SDValue> FP_TO_INTHelper(SDValue Op, SelectionDAG &DAG,
966 bool isReplace) const;
968 SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
969 SDValue LowerBUILD_VECTORvXi1(SDValue Op, SelectionDAG &DAG) const;
970 SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
971 SDValue LowerVSELECT(SDValue Op, SelectionDAG &DAG) const;
972 SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
973 SDValue ExtractBitFromMaskVector(SDValue Op, SelectionDAG &DAG) const;
974 SDValue InsertBitToMaskVector(SDValue Op, SelectionDAG &DAG) const;
976 SDValue LowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
977 SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
978 SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
979 SDValue LowerGlobalAddress(const GlobalValue *GV, SDLoc dl,
980 int64_t Offset, SelectionDAG &DAG) const;
981 SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
982 SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
983 SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
984 SDValue LowerSINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
985 SDValue LowerUINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
986 SDValue LowerUINT_TO_FP_i64(SDValue Op, SelectionDAG &DAG) const;
987 SDValue LowerUINT_TO_FP_i32(SDValue Op, SelectionDAG &DAG) const;
988 SDValue lowerUINT_TO_FP_vec(SDValue Op, SelectionDAG &DAG) const;
989 SDValue LowerTRUNCATE(SDValue Op, SelectionDAG &DAG) const;
990 SDValue LowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const;
991 SDValue LowerFP_TO_UINT(SDValue Op, SelectionDAG &DAG) const;
992 SDValue LowerToBT(SDValue And, ISD::CondCode CC,
993 SDLoc dl, SelectionDAG &DAG) const;
994 SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
995 SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
996 SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
997 SDValue LowerMEMSET(SDValue Op, SelectionDAG &DAG) const;
998 SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
999 SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
1000 SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
1001 SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG) const;
1002 SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
1003 SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
1004 SDValue LowerFRAME_TO_ARGS_OFFSET(SDValue Op, SelectionDAG &DAG) const;
1005 SDValue LowerEH_RETURN(SDValue Op, SelectionDAG &DAG) const;
1006 SDValue LowerCATCHRET(SDValue Op, SelectionDAG &DAG) const;
1007 SDValue lowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
1008 SDValue lowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
1009 SDValue LowerINIT_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
1010 SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
1011 SDValue LowerWin64_i128OP(SDValue Op, SelectionDAG &DAG) const;
1012 SDValue LowerGC_TRANSITION_START(SDValue Op, SelectionDAG &DAG) const;
1013 SDValue LowerGC_TRANSITION_END(SDValue Op, SelectionDAG &DAG) const;
1016 LowerFormalArguments(SDValue Chain,
1017 CallingConv::ID CallConv, bool isVarArg,
1018 const SmallVectorImpl<ISD::InputArg> &Ins,
1019 SDLoc dl, SelectionDAG &DAG,
1020 SmallVectorImpl<SDValue> &InVals) const override;
1021 SDValue LowerCall(CallLoweringInfo &CLI,
1022 SmallVectorImpl<SDValue> &InVals) const override;
1024 SDValue LowerReturn(SDValue Chain,
1025 CallingConv::ID CallConv, bool isVarArg,
1026 const SmallVectorImpl<ISD::OutputArg> &Outs,
1027 const SmallVectorImpl<SDValue> &OutVals,
1028 SDLoc dl, SelectionDAG &DAG) const override;
1030 bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const override;
1032 bool mayBeEmittedAsTailCall(CallInst *CI) const override;
1034 EVT getTypeForExtArgOrReturn(LLVMContext &Context, EVT VT,
1035 ISD::NodeType ExtendKind) const override;
1037 bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
1039 const SmallVectorImpl<ISD::OutputArg> &Outs,
1040 LLVMContext &Context) const override;
1042 const MCPhysReg *getScratchRegisters(CallingConv::ID CC) const override;
1044 bool shouldExpandAtomicLoadInIR(LoadInst *SI) const override;
1045 bool shouldExpandAtomicStoreInIR(StoreInst *SI) const override;
1046 TargetLoweringBase::AtomicRMWExpansionKind
1047 shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
1050 lowerIdempotentRMWIntoFencedLoad(AtomicRMWInst *AI) const override;
1052 bool needsCmpXchgNb(Type *MemType) const;
1054 /// Utility function to emit atomic-load-arith operations (and, or, xor,
1055 /// nand, max, min, umax, umin). It takes the corresponding instruction to
1056 /// expand, the associated machine basic block, and the associated X86
1057 /// opcodes for reg/reg.
1058 MachineBasicBlock *EmitAtomicLoadArith(MachineInstr *MI,
1059 MachineBasicBlock *MBB) const;
1061 /// Utility function to emit atomic-load-arith operations (and, or, xor,
1062 /// nand, add, sub, swap) for 64-bit operands on 32-bit target.
1063 MachineBasicBlock *EmitAtomicLoadArith6432(MachineInstr *MI,
1064 MachineBasicBlock *MBB) const;
1066 // Utility function to emit the low-level va_arg code for X86-64.
1067 MachineBasicBlock *EmitVAARG64WithCustomInserter(
1069 MachineBasicBlock *MBB) const;
1071 /// Utility function to emit the xmm reg save portion of va_start.
1072 MachineBasicBlock *EmitVAStartSaveXMMRegsWithCustomInserter(
1073 MachineInstr *BInstr,
1074 MachineBasicBlock *BB) const;
1076 MachineBasicBlock *EmitLoweredSelect(MachineInstr *I,
1077 MachineBasicBlock *BB) const;
1079 MachineBasicBlock *EmitLoweredAtomicFP(MachineInstr *I,
1080 MachineBasicBlock *BB) const;
1082 MachineBasicBlock *EmitLoweredWinAlloca(MachineInstr *MI,
1083 MachineBasicBlock *BB) const;
1085 MachineBasicBlock *EmitLoweredSegAlloca(MachineInstr *MI,
1086 MachineBasicBlock *BB) const;
1088 MachineBasicBlock *EmitLoweredTLSCall(MachineInstr *MI,
1089 MachineBasicBlock *BB) const;
1091 MachineBasicBlock *emitLoweredTLSAddr(MachineInstr *MI,
1092 MachineBasicBlock *BB) const;
1094 MachineBasicBlock *emitEHSjLjSetJmp(MachineInstr *MI,
1095 MachineBasicBlock *MBB) const;
1097 MachineBasicBlock *emitEHSjLjLongJmp(MachineInstr *MI,
1098 MachineBasicBlock *MBB) const;
1100 MachineBasicBlock *emitFMA3Instr(MachineInstr *MI,
1101 MachineBasicBlock *MBB) const;
1103 /// Emit nodes that will be selected as "test Op0,Op0", or something
1104 /// equivalent, for use with the given x86 condition code.
1105 SDValue EmitTest(SDValue Op0, unsigned X86CC, SDLoc dl,
1106 SelectionDAG &DAG) const;
1108 /// Emit nodes that will be selected as "cmp Op0,Op1", or something
1109 /// equivalent, for use with the given x86 condition code.
1110 SDValue EmitCmp(SDValue Op0, SDValue Op1, unsigned X86CC, SDLoc dl,
1111 SelectionDAG &DAG) const;
1113 /// Convert a comparison if required by the subtarget.
1114 SDValue ConvertCmpIfNecessary(SDValue Cmp, SelectionDAG &DAG) const;
1116 /// Use rsqrt* to speed up sqrt calculations.
1117 SDValue getRsqrtEstimate(SDValue Operand, DAGCombinerInfo &DCI,
1118 unsigned &RefinementSteps,
1119 bool &UseOneConstNR) const override;
1121 /// Use rcp* to speed up fdiv calculations.
1122 SDValue getRecipEstimate(SDValue Operand, DAGCombinerInfo &DCI,
1123 unsigned &RefinementSteps) const override;
1125 /// Reassociate floating point divisions into multiply by reciprocal.
1126 unsigned combineRepeatedFPDivisors() const override;
1130 FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
1131 const TargetLibraryInfo *libInfo);
1135 #endif // X86ISELLOWERING_H