luau-lang/luau
1
0
Fork 0
mirror of https://github.com/luau-lang/luau.git synced 2025-04-05 11:20:54 +01:00
Code Issues Projects Releases Packages Wiki Activity

Add optimization of a-0 and a+(-0)

Browse source 
This can sometimes be helpful after all.
This commit is contained in:
Arseny Kapoulkine 2024-11-27 10:01:29 +09:00
parent 301b06c152
commit d83ff5a8bd
1 changed files with 18 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
CodeGen/src/OptimizeConstProp.cpp
View file

@ -1194,8 +1194,25 @@ static void constPropInInst(ConstPropState& state, IrBuilder& build, IrFunction&
break;
case IrCmd::ADD_INT:
case IrCmd::SUB_INT:
state.substituteOrRecord(inst, index);
break;
case IrCmd::ADD_NUM:
case IrCmd::SUB_NUM:
if (FFlag::LuauCodeGenArithOpt)
{
if (std::optional<double> k = function.asDoubleOp(inst.b.kind == IrOpKind::Constant ? inst.b : state.tryGetValue(inst.b)))
{
// a + 0.0 and a - (-0.0) can't be folded since the behavior is different for negative zero
// however, a - 0.0 and a + (-0.0) can be folded into a
if (*k == 0.0 && bool(signbit(*k)) == (inst.cmd == IrCmd::ADD_NUM))
substitute(function, inst, inst.a);
else
state.substituteOrRecord(inst, index);
}
else
state.substituteOrRecord(inst, index);
}
else
state.substituteOrRecord(inst, index);
break;
case IrCmd::MUL_NUM: