constant_propagation_pass: Combine zero-extension folding code into its own function

Separates the behavior from the actual switch statement and gets rid of
duplication, now that we can use the general GetImmediateAsU64()
function.
This commit is contained in:
Lioncash 2018-10-05 17:45:33 -04:00 committed by MerryMage
parent 4c6a9535ca
commit 2274214ff0

View file

@ -113,6 +113,15 @@ void FoldOR(IR::Inst& inst, bool is_32_bit) {
inst.ReplaceUsesWith(lhs); inst.ReplaceUsesWith(lhs);
} }
} }
void FoldZeroExtendXToWord(IR::Inst& inst) {
if (!inst.AreAllArgsImmediates()) {
return;
}
const u64 value = inst.GetArg(0).GetImmediateAsU64();
inst.ReplaceUsesWith(IR::Value{static_cast<u32>(value)});
}
} // Anonymous namespace } // Anonymous namespace
void ConstantPropagation(IR::Block& block) { void ConstantPropagation(IR::Block& block) {
@ -154,24 +163,10 @@ void ConstantPropagation(IR::Block& block) {
case IR::Opcode::Not64: case IR::Opcode::Not64:
FoldNOT(inst, opcode == IR::Opcode::Not32); FoldNOT(inst, opcode == IR::Opcode::Not32);
break; break;
case IR::Opcode::ZeroExtendByteToWord: { case IR::Opcode::ZeroExtendByteToWord:
if (!inst.AreAllArgsImmediates()) case IR::Opcode::ZeroExtendHalfToWord:
break; FoldZeroExtendXToWord(inst);
u8 byte = inst.GetArg(0).GetU8();
u32 value = static_cast<u32>(byte);
inst.ReplaceUsesWith(IR::Value{value});
break; break;
}
case IR::Opcode::ZeroExtendHalfToWord: {
if (!inst.AreAllArgsImmediates())
break;
u16 half = inst.GetArg(0).GetU16();
u32 value = static_cast<u32>(half);
inst.ReplaceUsesWith(IR::Value{value});
break;
}
default: default:
break; break;
} }