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//==-- 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_TARGET_AARCH64_ISELLOWERING_H
#define LLVM_TARGET_AARCH64_ISELLOWERING_H
#include "Utils/AArch64BaseInfo.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Target/TargetLowering.h"
namespace llvm {
namespace AArch64ISD {
enum NodeType {
// Start the numbering from where ISD NodeType finishes.
FIRST_NUMBER = ISD::BUILTIN_OP_END,
// This is a conditional branch which also notes the flag needed
// (eq/sgt/...). A64 puts this information on the branches rather than
// compares as LLVM does.
BR_CC,
// A node to be selected to an actual call operation: either BL or BLR in
// the absence of tail calls.
Call,
// Indicates a floating-point immediate which fits into the format required
// by the FMOV instructions. First (and only) operand is the 8-bit encoded
// value of that immediate.
FPMOV,
// Corresponds directly to an EXTR instruction. Operands are an LHS an RHS
// and an LSB.
EXTR,
// Wraps a load from the GOT, which should always be performed with a 64-bit
// load instruction. This prevents the DAG combiner folding a truncate to
// form a smaller memory access.
GOTLoad,
// Performs a bitfield insert. Arguments are: the value being inserted into;
// the value being inserted; least significant bit changed; width of the
// field.
BFI,
// Simply a convenient node inserted during ISelLowering to represent
// procedure return. Will almost certainly be selected to "RET".
Ret,
/// Extracts a field of contiguous bits from the source and sign extends
/// them into a single register. Arguments are: source; immr; imms. Note
/// these are pre-encoded since DAG matching can't cope with combining LSB
/// and Width into these values itself.
SBFX,
/// This is an A64-ification of the standard LLVM SELECT_CC operation. The
/// main difference is that it only has the values and an A64 condition,
/// which will be produced by a setcc instruction.
SELECT_CC,
/// This serves most of the functions of the LLVM SETCC instruction, for two
/// purposes. First, it prevents optimisations from fiddling with the
/// compare after we've moved the CondCode information onto the SELECT_CC or
/// BR_CC instructions. Second, it gives a legal instruction for the actual
/// comparison.
///
/// It keeps a record of the condition flags asked for because certain
/// instructions are only valid for a subset of condition codes.
SETCC,
// Designates a node which is a tail call: both a call and a return
// instruction as far as selction is concerned. It should be selected to an
// unconditional branch. Has the usual plethora of call operands, but: 1st
// is callee, 2nd is stack adjustment required immediately before branch.
TC_RETURN,
// Designates a call used to support the TLS descriptor ABI. The call itself
// will be indirect ("BLR xN") but a relocation-specifier (".tlsdesccall
// var") must be attached somehow during code generation. It takes two
// operands: the callee and the symbol to be relocated against.
TLSDESCCALL,
// Leaf node which will be lowered to an appropriate MRS to obtain the
// thread pointer: TPIDR_EL0.
THREAD_POINTER,
/// Extracts a field of contiguous bits from the source and zero extends
/// them into a single register. Arguments are: source; immr; imms. Note
/// these are pre-encoded since DAG matching can't cope with combining LSB
/// and Width into these values itself.
UBFX,
// Wraps an address which the ISelLowering phase has decided should be
// created using the small absolute memory model: i.e. adrp/add or
// adrp/mem-op. This exists to prevent bare TargetAddresses which may never
// get selected.
WrapperSmall
};
}
class AArch64Subtarget;
class AArch64TargetMachine;
class AArch64TargetLowering : public TargetLowering {
public:
explicit AArch64TargetLowering(AArch64TargetMachine &TM);
const char *getTargetNodeName(unsigned Opcode) const;
CCAssignFn *CCAssignFnForNode(CallingConv::ID CC) const;
SDValue LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue LowerReturn(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl, SelectionDAG &DAG) const;
SDValue LowerCall(CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const;
SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
CallingConv::ID CallConv, bool IsVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
void SaveVarArgRegisters(CCState &CCInfo, SelectionDAG &DAG,
DebugLoc DL, SDValue &Chain) const;
/// IsEligibleForTailCallOptimization - Check whether the call is eligible
/// for tail call optimization. Targets which want to do tail call
/// optimization should implement this function.
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;
EVT getSetCCResultType(EVT VT) const;
bool DoesCalleeRestoreStack(CallingConv::ID CallCC, bool TailCallOpt) const;
bool IsTailCallConvention(CallingConv::ID CallCC) const;
SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
bool isLegalICmpImmediate(int64_t Val) const;
SDValue getSelectableIntSetCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
SDValue &A64cc, SelectionDAG &DAG, DebugLoc &dl) const;
virtual MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *MBB) const;
MachineBasicBlock *
emitAtomicBinary(MachineInstr *MI, MachineBasicBlock *MBB,
unsigned Size, unsigned Opcode) const;
MachineBasicBlock *
emitAtomicBinaryMinMax(MachineInstr *MI, MachineBasicBlock *BB,
unsigned Size, unsigned CmpOp,
A64CC::CondCodes Cond) const;
MachineBasicBlock *
emitAtomicCmpSwap(MachineInstr *MI, MachineBasicBlock *BB,
unsigned Size) const;
MachineBasicBlock *
EmitF128CSEL(MachineInstr *MI, MachineBasicBlock *MBB) const;
SDValue LowerATOMIC_FENCE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerATOMIC_STORE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerF128ToCall(SDValue Op, SelectionDAG &DAG,
RTLIB::Libcall Call) 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, bool IsSigned) const;
SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerTLSDescCall(SDValue SymAddr, SDValue DescAddr, DebugLoc DL,
SelectionDAG &DAG) const;
SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG, bool IsSigned) const;
SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVACOPY(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
/// isFMAFasterThanMulAndAdd - Return true if an FMA operation is faster than
/// a pair of mul and add instructions. fmuladd intrinsics will be expanded to
/// FMAs when this method returns true (and FMAs are legal), otherwise fmuladd
/// is expanded to mul + add.
virtual bool isFMAFasterThanMulAndAdd(EVT) const { return true; }
ConstraintType getConstraintType(const std::string &Constraint) const;
ConstraintWeight getSingleConstraintMatchWeight(AsmOperandInfo &Info,
const char *Constraint) const;
void LowerAsmOperandForConstraint(SDValue Op,
std::string &Constraint,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const;
std::pair<unsigned, const TargetRegisterClass*>
getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const;
private:
const AArch64Subtarget *Subtarget;
const TargetRegisterInfo *RegInfo;
const InstrItineraryData *Itins;
};
} // namespace llvm
#endif // LLVM_TARGET_AARCH64_ISELLOWERING_H