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RedundantFlagCalculationElimination: drop unneeded bools

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nonzero <==> not dummy

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
This commit is contained in:
Alyssa Rosenzweig committed 2024-09-07 10:59:05 -04:00
1 parent c350888d70
commit 249de7c758
1 file changed
+6 -21
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FEXCore/Source/Interface/IR/Passes/RedundantFlagCalculationElimination.cpp
+6 -21
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@@ -46,14 +46,10 @@ struct FlagInfo {
// eliminated.
bool CanEliminate;
// If true, the opcode can be replaced with Replacement if its flag writes can
// all be eliminated.
bool CanReplace;
// If set, the opcode can be replaced with Replacement if its flag writes can
// all be eliminated, or ReplacementNoWrite if its register write can be
// eliminated.
IROps Replacement;
// If true, the opcode can be replaced with ReplacementNoWrite if its register
// write is unused but its flags are still needed.
bool CanReplaceWrite;
IROps ReplacementNoWrite;
};
@@ -108,27 +104,21 @@ FlagInfo DeadFlagCalculationEliminination::Classify(IROp_Header* IROp) {
case OP_ANDWITHFLAGS:
return {
.Write = FLAG_NZCV,
.CanReplace = true,
.Replacement = OP_AND,
.CanReplaceWrite = true,
.ReplacementNoWrite = OP_TESTNZ,
};
case OP_ADDWITHFLAGS:
return {
.Write = FLAG_NZCV,
.CanReplace = true,
.Replacement = OP_ADD,
.CanReplaceWrite = true,
.ReplacementNoWrite = OP_ADDNZCV,
};
case OP_SUBWITHFLAGS:
return {
.Write = FLAG_NZCV,
.CanReplace = true,
.Replacement = OP_SUB,
.CanReplaceWrite = true,
.ReplacementNoWrite = OP_SUBNZCV,
};
@@ -136,9 +126,7 @@ FlagInfo DeadFlagCalculationEliminination::Classify(IROp_Header* IROp) {
return {
.Read = FLAG_C,
.Write = FLAG_NZCV,
.CanReplace = true,
.Replacement = OP_ADC,
.CanReplaceWrite = true,
.ReplacementNoWrite = OP_ADCNZCV,
};
@@ -146,7 +134,6 @@ FlagInfo DeadFlagCalculationEliminination::Classify(IROp_Header* IROp) {
return {
.Read = FLAG_C,
.Write = FLAG_NZCV,
.CanReplace = true,
.Replacement = OP_ADCZERO,
};
@@ -154,9 +141,7 @@ FlagInfo DeadFlagCalculationEliminination::Classify(IROp_Header* IROp) {
return {
.Read = FLAG_C,
.Write = FLAG_NZCV,
.CanReplace = true,
.Replacement = OP_SBB,
.CanReplaceWrite = true,
.ReplacementNoWrite = OP_SBBNZCV,
};
@@ -413,16 +398,16 @@ void DeadFlagCalculationEliminination::Run(IREmitter* IREmit) {
bool Eliminated = false;
if ((FlagsRead & Info.Write) == 0) {
if ((Info.CanEliminate || Info.CanReplace) && CodeNode->GetUses() == 0) {
if ((Info.CanEliminate || Info.Replacement) && CodeNode->GetUses() == 0) {
IREmit->Remove(CodeNode);
Eliminated = true;
} else if (Info.CanReplace) {
} else if (Info.Replacement) {
IROp->Op = Info.Replacement;
}
} else {
FlagsRead &= ~Info.Write;
if (Info.CanReplaceWrite && CodeNode->GetUses() == 0) {
if (Info.ReplacementNoWrite && CodeNode->GetUses() == 0) {
IROp->Op = Info.ReplacementNoWrite;
}
}