Files
clang-p2996/llvm/lib/MC/MCInstrDesc.cpp
Jay Foad 073401e59c [MC] Define and use MCInstrDesc implicit_uses and implicit_defs. NFC.
The new methods return a range for easier iteration. Use them everywhere
instead of getImplicitUses, getNumImplicitUses, getImplicitDefs and
getNumImplicitDefs. A future patch will remove the old methods.

In some use cases the new methods are less efficient because they always
have to scan the whole uses/defs array to count its length, but that
will be fixed in a future patch by storing the number of implicit
uses/defs explicitly in MCInstrDesc. At that point there will be no need
to 0-terminate the arrays.

Differential Revision: https://reviews.llvm.org/D142215
2023-01-23 14:44:58 +00:00

53 lines
1.9 KiB
C++

//===------ llvm/MC/MCInstrDesc.cpp- Instruction Descriptors --------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines methods on the MCOperandInfo and MCInstrDesc classes, which
// are used to describe target instructions and their operands.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCRegisterInfo.h"
using namespace llvm;
bool MCInstrDesc::mayAffectControlFlow(const MCInst &MI,
const MCRegisterInfo &RI) const {
if (isBranch() || isCall() || isReturn() || isIndirectBranch())
return true;
unsigned PC = RI.getProgramCounter();
if (PC == 0)
return false;
if (hasDefOfPhysReg(MI, PC, RI))
return true;
return false;
}
bool MCInstrDesc::hasImplicitDefOfPhysReg(unsigned Reg,
const MCRegisterInfo *MRI) const {
for (MCPhysReg ImpDef : implicit_defs())
if (ImpDef == Reg || (MRI && MRI->isSubRegister(Reg, ImpDef)))
return true;
return false;
}
bool MCInstrDesc::hasDefOfPhysReg(const MCInst &MI, unsigned Reg,
const MCRegisterInfo &RI) const {
for (int i = 0, e = NumDefs; i != e; ++i)
if (MI.getOperand(i).isReg() &&
RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
return true;
if (variadicOpsAreDefs())
for (int i = NumOperands - 1, e = MI.getNumOperands(); i != e; ++i)
if (MI.getOperand(i).isReg() &&
RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
return true;
return hasImplicitDefOfPhysReg(Reg, &RI);
}