//==-- llvm/CodeGen/GlobalISel/Utils.h ---------------------------*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file This file declares the API of helper functions used throughout the
/// GlobalISel pipeline.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_GLOBALISEL_UTILS_H
#define LLVM_CODEGEN_GLOBALISEL_UTILS_H
#include "llvm/ADT/StringRef.h"
namespace llvm {
class MachineFunction;
class MachineInstr;
class MachineOperand;
class MachineOptimizationRemarkEmitter;
class MachineOptimizationRemarkMissed;
class MachineRegisterInfo;
class MCInstrDesc;
class RegisterBankInfo;
class TargetInstrInfo;
class TargetPassConfig;
class TargetRegisterInfo;
class TargetRegisterClass;
class Twine;
class ConstantFP;
class APFloat;
/// Try to constrain Reg to the specified register class. If this fails,
/// create a new virtual register in the correct class and insert a COPY before
/// \p InsertPt. The debug location of \p InsertPt is used for the new copy.
///
/// \return The virtual register constrained to the right register class.
unsigned constrainRegToClass(MachineRegisterInfo &MRI,
const TargetInstrInfo &TII,
const RegisterBankInfo &RBI,
MachineInstr &InsertPt, unsigned Reg,
const TargetRegisterClass &RegClass);
/// Try to constrain Reg so that it is usable by argument OpIdx of the
/// provided MCInstrDesc \p II. If this fails, create a new virtual
/// register in the correct class and insert a COPY before \p InsertPt.
/// This is equivalent to constrainRegToClass() with RegClass obtained from the
/// MCInstrDesc. The debug location of \p InsertPt is used for the new copy.
///
/// \return The virtual register constrained to the right register class.
unsigned constrainOperandRegClass(const MachineFunction &MF,
const TargetRegisterInfo &TRI,
MachineRegisterInfo &MRI,
const TargetInstrInfo &TII,
const RegisterBankInfo &RBI,
MachineInstr &InsertPt, const MCInstrDesc &II,
const MachineOperand &RegMO, unsigned OpIdx);
/// Mutate the newly-selected instruction \p I to constrain its (possibly
/// generic) virtual register operands to the instruction's register class.
/// This could involve inserting COPYs before (for uses) or after (for defs).
/// This requires the number of operands to match the instruction description.
/// \returns whether operand regclass constraining succeeded.
///
// FIXME: Not all instructions have the same number of operands. We should
// probably expose a constrain helper per operand and let the target selector
// constrain individual registers, like fast-isel.
bool constrainSelectedInstRegOperands(MachineInstr &I,
const TargetInstrInfo &TII,
const TargetRegisterInfo &TRI,
const RegisterBankInfo &RBI);
/// Check whether an instruction \p MI is dead: it only defines dead virtual
/// registers, and doesn't have other side effects.
bool isTriviallyDead(const MachineInstr &MI, const MachineRegisterInfo &MRI);
/// Report an ISel error as a missed optimization remark to the LLVMContext's
/// diagnostic stream. Set the FailedISel MachineFunction property.
void reportGISelFailure(MachineFunction &MF, const TargetPassConfig &TPC,
MachineOptimizationRemarkEmitter &MORE,
MachineOptimizationRemarkMissed &R);
void reportGISelFailure(MachineFunction &MF, const TargetPassConfig &TPC,
MachineOptimizationRemarkEmitter &MORE,
const char *PassName, StringRef Msg,
const MachineInstr &MI);
Optional<int64_t> getConstantVRegVal(unsigned VReg,
const MachineRegisterInfo &MRI);
const ConstantFP* getConstantFPVRegVal(unsigned VReg,
const MachineRegisterInfo &MRI);
/// See if Reg is defined by an single def instruction that is
/// Opcode. Also try to do trivial folding if it's a COPY with
/// same types. Returns null otherwise.
MachineInstr *getOpcodeDef(unsigned Opcode, unsigned Reg,
const MachineRegisterInfo &MRI);
/// Returns an APFloat from Val converted to the appropriate size.
APFloat getAPFloatFromSize(double Val, unsigned Size);
} // End namespace llvm.
#endif