lib/MC/MCInstrDesc.cpp

   1 //===------ llvm/MC/MCInstrDesc.cpp- Instruction Descriptors --------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines methods on the MCOperandInfo and MCInstrDesc classes, which
  10 // are used to describe target instructions and their operands.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/MC/MCInstrDesc.h"
  15 #include "llvm/MC/MCInst.h"
  16 #include "llvm/MC/MCRegisterInfo.h"
  17 #include "llvm/MC/MCSubtargetInfo.h"
  18
  19 using namespace llvm;
  20
  21 bool MCInstrDesc::getDeprecatedInfo(MCInst &MI, const MCSubtargetInfo &STI,
  22                                     std::string &Info) const {
  23   if (ComplexDeprecationInfo)
  24     return ComplexDeprecationInfo(MI, STI, Info);
  25   if (DeprecatedFeature != -1 && STI.getFeatureBits()[DeprecatedFeature]) {
  26     // FIXME: it would be nice to include the subtarget feature here.
  27     Info = "deprecated";
  28     return true;
  29   }
  30   return false;
  31 }
  32 bool MCInstrDesc::mayAffectControlFlow(const MCInst &MI,
  33                                        const MCRegisterInfo &RI) const {
  34   if (isBranch() || isCall() || isReturn() || isIndirectBranch())
  35     return true;
  36   unsigned PC = RI.getProgramCounter();
  37   if (PC == 0)
  38     return false;
  39   if (hasDefOfPhysReg(MI, PC, RI))
  40     return true;
  41   return false;
  42 }
  43
  44 bool MCInstrDesc::hasImplicitDefOfPhysReg(unsigned Reg,
  45                                           const MCRegisterInfo *MRI) const {
  46   if (const MCPhysReg *ImpDefs = ImplicitDefs)
  47     for (; *ImpDefs; ++ImpDefs)
  48       if (*ImpDefs == Reg || (MRI && MRI->isSubRegister(Reg, *ImpDefs)))
  49         return true;
  50   return false;
  51 }
  52
  53 bool MCInstrDesc::hasDefOfPhysReg(const MCInst &MI, unsigned Reg,
  54                                   const MCRegisterInfo &RI) const {
  55   for (int i = 0, e = NumDefs; i != e; ++i)
  56     if (MI.getOperand(i).isReg() &&
  57         RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
  58       return true;
  59   if (variadicOpsAreDefs())
  60     for (int i = NumOperands - 1, e = MI.getNumOperands(); i != e; ++i)
  61       if (MI.getOperand(i).isReg() &&
  62           RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
  63         return true;
  64   return hasImplicitDefOfPhysReg(Reg, &RI);
  65 }