llvm-6502/lib/Target/AArch64/AArch64ISelLowering.h
Matthias Braun 66b12088cb AArch64: Implement conditional compare sequence matching.
This is a new iteration of the reverted r238793 /
http://reviews.llvm.org/D8232 which wrongly assumed that any and/or
trees can be represented by conditional compare sequences, however there
are some restrictions to that. This version fixes this and adds comments
that explain exactly what types of and/or trees can actually be
implemented as conditional compare sequences.

Related to http://llvm.org/PR20927, rdar://18326194

Differential Revision: http://reviews.llvm.org/D10579

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242436 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 20:02:37 +00:00

536 lines
19 KiB
C++

//==-- AArch64ISelLowering.h - AArch64 DAG Lowering Interface ----*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that AArch64 uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_AARCH64_AARCH64ISELLOWERING_H
#define LLVM_LIB_TARGET_AARCH64_AARCH64ISELLOWERING_H
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Instruction.h"
#include "llvm/Target/TargetLowering.h"
namespace llvm {
namespace AArch64ISD {
enum NodeType : unsigned {
FIRST_NUMBER = ISD::BUILTIN_OP_END,
WrapperLarge, // 4-instruction MOVZ/MOVK sequence for 64-bit addresses.
CALL, // Function call.
// Produces the full sequence of instructions for getting the thread pointer
// offset of a variable into X0, using the TLSDesc model.
TLSDESC_CALLSEQ,
ADRP, // Page address of a TargetGlobalAddress operand.
ADDlow, // Add the low 12 bits of a TargetGlobalAddress operand.
LOADgot, // Load from automatically generated descriptor (e.g. Global
// Offset Table, TLS record).
RET_FLAG, // Return with a flag operand. Operand 0 is the chain operand.
BRCOND, // Conditional branch instruction; "b.cond".
CSEL,
FCSEL, // Conditional move instruction.
CSINV, // Conditional select invert.
CSNEG, // Conditional select negate.
CSINC, // Conditional select increment.
// Pointer to the thread's local storage area. Materialised from TPIDR_EL0 on
// ELF.
THREAD_POINTER,
ADC,
SBC, // adc, sbc instructions
// Arithmetic instructions which write flags.
ADDS,
SUBS,
ADCS,
SBCS,
ANDS,
// Conditional compares. Operands: left,right,falsecc,cc,flags
CCMP,
CCMN,
FCCMP,
// Floating point comparison
FCMP,
// Floating point max and min instructions.
FMAX,
FMIN,
// Scalar extract
EXTR,
// Scalar-to-vector duplication
DUP,
DUPLANE8,
DUPLANE16,
DUPLANE32,
DUPLANE64,
// Vector immedate moves
MOVI,
MOVIshift,
MOVIedit,
MOVImsl,
FMOV,
MVNIshift,
MVNImsl,
// Vector immediate ops
BICi,
ORRi,
// Vector bit select: similar to ISD::VSELECT but not all bits within an
// element must be identical.
BSL,
// Vector arithmetic negation
NEG,
// Vector shuffles
ZIP1,
ZIP2,
UZP1,
UZP2,
TRN1,
TRN2,
REV16,
REV32,
REV64,
EXT,
// Vector shift by scalar
VSHL,
VLSHR,
VASHR,
// Vector shift by scalar (again)
SQSHL_I,
UQSHL_I,
SQSHLU_I,
SRSHR_I,
URSHR_I,
// Vector comparisons
CMEQ,
CMGE,
CMGT,
CMHI,
CMHS,
FCMEQ,
FCMGE,
FCMGT,
// Vector zero comparisons
CMEQz,
CMGEz,
CMGTz,
CMLEz,
CMLTz,
FCMEQz,
FCMGEz,
FCMGTz,
FCMLEz,
FCMLTz,
// Vector across-lanes addition
// Only the lower result lane is defined.
SADDV,
UADDV,
// Vector across-lanes min/max
// Only the lower result lane is defined.
SMINV,
UMINV,
SMAXV,
UMAXV,
// Vector bitwise negation
NOT,
// Vector bitwise selection
BIT,
// Compare-and-branch
CBZ,
CBNZ,
TBZ,
TBNZ,
// Tail calls
TC_RETURN,
// Custom prefetch handling
PREFETCH,
// {s|u}int to FP within a FP register.
SITOF,
UITOF,
/// Natural vector cast. ISD::BITCAST is not natural in the big-endian
/// world w.r.t vectors; which causes additional REV instructions to be
/// generated to compensate for the byte-swapping. But sometimes we do
/// need to re-interpret the data in SIMD vector registers in big-endian
/// mode without emitting such REV instructions.
NVCAST,
SMULL,
UMULL,
// NEON Load/Store with post-increment base updates
LD2post = ISD::FIRST_TARGET_MEMORY_OPCODE,
LD3post,
LD4post,
ST2post,
ST3post,
ST4post,
LD1x2post,
LD1x3post,
LD1x4post,
ST1x2post,
ST1x3post,
ST1x4post,
LD1DUPpost,
LD2DUPpost,
LD3DUPpost,
LD4DUPpost,
LD1LANEpost,
LD2LANEpost,
LD3LANEpost,
LD4LANEpost,
ST2LANEpost,
ST3LANEpost,
ST4LANEpost
};
} // end namespace AArch64ISD
class AArch64Subtarget;
class AArch64TargetMachine;
class AArch64TargetLowering : public TargetLowering {
bool RequireStrictAlign;
public:
explicit AArch64TargetLowering(const TargetMachine &TM,
const AArch64Subtarget &STI);
/// Selects the correct CCAssignFn for a given CallingConvention value.
CCAssignFn *CCAssignFnForCall(CallingConv::ID CC, bool IsVarArg) const;
/// computeKnownBitsForTargetNode - Determine which of the bits specified in
/// Mask are known to be either zero or one and return them in the
/// KnownZero/KnownOne bitsets.
void computeKnownBitsForTargetNode(const SDValue Op, APInt &KnownZero,
APInt &KnownOne, const SelectionDAG &DAG,
unsigned Depth = 0) const override;
MVT getScalarShiftAmountTy(const DataLayout &DL, EVT) const override;
/// allowsMisalignedMemoryAccesses - Returns true if the target allows
/// unaligned memory accesses of the specified type.
bool allowsMisalignedMemoryAccesses(EVT VT, unsigned AddrSpace = 0,
unsigned Align = 1,
bool *Fast = nullptr) const override {
if (RequireStrictAlign)
return false;
// FIXME: True for Cyclone, but not necessary others.
if (Fast)
*Fast = true;
return true;
}
/// LowerOperation - Provide custom lowering hooks for some operations.
SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
const char *getTargetNodeName(unsigned Opcode) const override;
SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
/// getFunctionAlignment - Return the Log2 alignment of this function.
unsigned getFunctionAlignment(const Function *F) const;
/// Returns true if a cast between SrcAS and DestAS is a noop.
bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override {
// Addrspacecasts are always noops.
return true;
}
/// createFastISel - This method returns a target specific FastISel object,
/// or null if the target does not support "fast" ISel.
FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo) const override;
bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
/// isShuffleMaskLegal - Return true if the given shuffle mask can be
/// codegen'd directly, or if it should be stack expanded.
bool isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const override;
/// getSetCCResultType - Return the ISD::SETCC ValueType
EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
EVT VT) const override;
SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
MachineBasicBlock *EmitF128CSEL(MachineInstr *MI,
MachineBasicBlock *BB) const;
MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *MBB) const override;
bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
unsigned Intrinsic) const override;
bool isTruncateFree(Type *Ty1, Type *Ty2) const override;
bool isTruncateFree(EVT VT1, EVT VT2) const override;
bool isProfitableToHoist(Instruction *I) const override;
bool isZExtFree(Type *Ty1, Type *Ty2) const override;
bool isZExtFree(EVT VT1, EVT VT2) const override;
bool isZExtFree(SDValue Val, EVT VT2) const override;
bool hasPairedLoad(Type *LoadedType,
unsigned &RequiredAligment) const override;
bool hasPairedLoad(EVT LoadedType, unsigned &RequiredAligment) const override;
unsigned getMaxSupportedInterleaveFactor() const override { return 4; }
bool lowerInterleavedLoad(LoadInst *LI,
ArrayRef<ShuffleVectorInst *> Shuffles,
ArrayRef<unsigned> Indices,
unsigned Factor) const override;
bool lowerInterleavedStore(StoreInst *SI, ShuffleVectorInst *SVI,
unsigned Factor) const override;
bool isLegalAddImmediate(int64_t) const override;
bool isLegalICmpImmediate(int64_t) const override;
EVT getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
bool IsMemset, bool ZeroMemset, bool MemcpyStrSrc,
MachineFunction &MF) const override;
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
unsigned AS) const override;
/// \brief Return the cost of the scaling factor used in the addressing
/// mode represented by AM for this target, for a load/store
/// of the specified type.
/// If the AM is supported, the return value must be >= 0.
/// If the AM is not supported, it returns a negative value.
int getScalingFactorCost(const DataLayout &DL, const AddrMode &AM, Type *Ty,
unsigned AS) const override;
/// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
/// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
/// expanded to FMAs when this method returns true, otherwise fmuladd is
/// expanded to fmul + fadd.
bool isFMAFasterThanFMulAndFAdd(EVT VT) const override;
const MCPhysReg *getScratchRegisters(CallingConv::ID CC) const override;
/// \brief Returns false if N is a bit extraction pattern of (X >> C) & Mask.
bool isDesirableToCommuteWithShift(const SDNode *N) const override;
/// \brief Returns true if it is beneficial to convert a load of a constant
/// to just the constant itself.
bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
Type *Ty) const override;
bool hasLoadLinkedStoreConditional() const override;
Value *emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
AtomicOrdering Ord) const override;
Value *emitStoreConditional(IRBuilder<> &Builder, Value *Val,
Value *Addr, AtomicOrdering Ord) const override;
bool shouldExpandAtomicLoadInIR(LoadInst *LI) const override;
bool shouldExpandAtomicStoreInIR(StoreInst *SI) const override;
TargetLoweringBase::AtomicRMWExpansionKind
shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
bool useLoadStackGuardNode() const override;
TargetLoweringBase::LegalizeTypeAction
getPreferredVectorAction(EVT VT) const override;
private:
bool isExtFreeImpl(const Instruction *Ext) const override;
/// Subtarget - Keep a pointer to the AArch64Subtarget around so that we can
/// make the right decision when generating code for different targets.
const AArch64Subtarget *Subtarget;
void addTypeForNEON(EVT VT, EVT PromotedBitwiseVT);
void addDRTypeForNEON(MVT VT);
void addQRTypeForNEON(MVT VT);
SDValue
LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL,
SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const override;
SDValue LowerCall(CallLoweringInfo & /*CLI*/,
SmallVectorImpl<SDValue> &InVals) const override;
SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL,
SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
bool isThisReturn, SDValue ThisVal) const;
bool isEligibleForTailCallOptimization(
SDValue Callee, CallingConv::ID CalleeCC, bool isVarArg,
bool isCalleeStructRet, bool isCallerStructRet,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG &DAG) const;
/// Finds the incoming stack arguments which overlap the given fixed stack
/// object and incorporates their load into the current chain. This prevents
/// an upcoming store from clobbering the stack argument before it's used.
SDValue addTokenForArgument(SDValue Chain, SelectionDAG &DAG,
MachineFrameInfo *MFI, int ClobberedFI) const;
bool DoesCalleeRestoreStack(CallingConv::ID CallCC, bool TailCallOpt) const;
bool IsTailCallConvention(CallingConv::ID CallCC) const;
void saveVarArgRegisters(CCState &CCInfo, SelectionDAG &DAG, SDLoc DL,
SDValue &Chain) const;
bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
LLVMContext &Context) const override;
SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals, SDLoc DL,
SelectionDAG &DAG) const override;
SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerDarwinGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerELFGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerELFTLSDescCallSeq(SDValue SymAddr, SDLoc DL,
SelectionDAG &DAG) const;
SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT_CC(ISD::CondCode CC, SDValue LHS, SDValue RHS,
SDValue TVal, SDValue FVal, SDLoc dl,
SelectionDAG &DAG) const;
SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerAAPCS_VASTART(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerDarwin_VASTART(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVACOPY(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerEXTRACT_SUBVECTOR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVectorSRA_SRL_SHL(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVSETCC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerCTPOP(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerF128Call(SDValue Op, SelectionDAG &DAG,
RTLIB::Libcall Call) const;
SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFP_ROUND(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVectorAND(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVectorOR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const;
SDValue BuildSDIVPow2(SDNode *N, const APInt &Divisor, SelectionDAG &DAG,
std::vector<SDNode *> *Created) const override;
bool combineRepeatedFPDivisors(unsigned NumUsers) const override;
ConstraintType getConstraintType(StringRef Constraint) const override;
unsigned getRegisterByName(const char* RegName, EVT VT,
SelectionDAG &DAG) const override;
/// Examine constraint string and operand type and determine a weight value.
/// The operand object must already have been set up with the operand type.
ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo &info,
const char *constraint) const override;
std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
StringRef Constraint, MVT VT) const override;
void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const override;
unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
if (ConstraintCode == "Q")
return InlineAsm::Constraint_Q;
// FIXME: clang has code for 'Ump', 'Utf', 'Usa', and 'Ush' but these are
// followed by llvm_unreachable so we'll leave them unimplemented in
// the backend for now.
return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
}
bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const override;
bool mayBeEmittedAsTailCall(CallInst *CI) const override;
bool getIndexedAddressParts(SDNode *Op, SDValue &Base, SDValue &Offset,
ISD::MemIndexedMode &AM, bool &IsInc,
SelectionDAG &DAG) const;
bool getPreIndexedAddressParts(SDNode *N, SDValue &Base, SDValue &Offset,
ISD::MemIndexedMode &AM,
SelectionDAG &DAG) const override;
bool getPostIndexedAddressParts(SDNode *N, SDNode *Op, SDValue &Base,
SDValue &Offset, ISD::MemIndexedMode &AM,
SelectionDAG &DAG) const override;
void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
SelectionDAG &DAG) const override;
bool functionArgumentNeedsConsecutiveRegisters(Type *Ty,
CallingConv::ID CallConv,
bool isVarArg) const override;
bool shouldNormalizeToSelectSequence(LLVMContext &, EVT) const override;
};
namespace AArch64 {
FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo);
} // end namespace AArch64
} // end namespace llvm
#endif