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Native code peephole optimisation for commutative instructions

This commit is contained in:
drmortalwombat 2021-09-20 13:02:38 +02:00
parent d3d20bee26
commit 78886f11f7
2 changed files with 17 additions and 1 deletions
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17
oscar64/NativeCodeGenerator.cpp
View File

@ -71,7 +71,7 @@ bool NativeCodeInstruction::IsUsedResultInstructions(NumberSet& requiredTemps)
mLive |= LIVE_CPU_REG_Z;
if (requiredTemps[CPU_REG_C])
mLive |= LIVE_CPU_REG_C;
if (mMode == ASMIM_ZERO_PAGE)
if (mMode == ASMIM_ZERO_PAGE && requiredTemps[mAddress])
mLive |= LIVE_MEM;
if (mType == ASMIT_JSR)
@ -446,6 +446,11 @@ bool NativeCodeInstruction::ChangesAddress(void) const
return false;
}
bool NativeCodeInstruction::IsCommutative(void) const
{
return mType == ASMIT_ADC || mType == ASMIT_AND || mType == ASMIT_ORA || mType == ASMIT_EOR;
}
bool NativeCodeInstruction::SameEffectiveAddress(const NativeCodeInstruction& ins) const
{
@ -4080,6 +4085,16 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(void)
mIns[i + 2].mType = ASMIT_STA;
progress = true;
}
else if (mIns[i + 0].mType == ASMIT_STA && mIns[i + 0].mMode == ASMIM_ZERO_PAGE &&
mIns[i + 1].mType == ASMIT_LDA && mIns[i + 1].mMode != ASMIM_ZERO_PAGE &&
mIns[i + 2].mMode == ASMIM_ZERO_PAGE && mIns[i + 0].mAddress == mIns[i + 2].mAddress &&
mIns[i + 2].IsCommutative() && HasAsmInstructionMode(mIns[i + 2].mType, mIns[i + 1].mMode) &&
(mIns[i + 2].mLive & LIVE_MEM) == 0)
{
mIns[i + 1].mType = mIns[i + 2].mType;
mIns[i + 0].mType = ASMIT_NOP;
mIns[i + 2].mType = ASMIT_NOP;
}
}
if (i + 3 < mIns.Size())

1
oscar64/NativeCodeGenerator.h
View File

@ -47,6 +47,7 @@ public:
bool LoadsAccu(void) const;
bool ChangesAddress(void) const;
bool SameEffectiveAddress(const NativeCodeInstruction& ins) const;
bool IsCommutative(void) const;
};
class NativeCodeBasicBlock