SSATmp* TraceBuilder::preOptimizeStLoc(IRInstruction* inst) {
// Guard relaxation might change the current local type, so don't try to
// change to StLocNT until after relaxation happens.
if (!inReoptimize()) return nullptr;
auto locId = inst->extra<StLoc>()->locId;
auto const curType = localType(locId, DataTypeGeneric);
auto const newType = inst->src(1)->type();
assert(inst->typeParam() == Type::None);
/*
* There's no need to store the type if it's going to be the same
* KindOfFoo. We'll still have to store string types because we
* aren't specific about storing KindOfStaticString
* vs. KindOfString, and a Type::Null might mean KindOfUninit or
* KindOfNull.
*/
auto const bothBoxed = curType.isBoxed() && newType.isBoxed();
auto const sameUnboxed = [&] {
auto avoidable = { Type::Uninit,
Type::InitNull,
Type::Int,
Type::Dbl,
// No strings.
Type::Arr,
Type::Obj,
Type::Res };
for (auto& t : avoidable) {
if (curType.subtypeOf(t) && newType.subtypeOf(t)) return true;
}
return false;
};
if (bothBoxed || sameUnboxed()) {
inst->setOpcode(StLocNT);
}
return nullptr;
}
SSATmp* TraceBuilder::preOptimizeStLoc(IRInstruction* inst) {
// Guard relaxation might change the current local type, so don't try to
// change to StLocNT until after relaxation happens.
if (!inReoptimize()) return nullptr;
auto locId = inst->extra<StLoc>()->locId;
auto const curType = localType(locId, DataTypeGeneric);
auto const newType = inst->src(1)->type();
assert(inst->typeParam() == Type::None);
// There's no need to store the type if it's going to be the same
// KindOfFoo. We still have to store string types because we don't
// guard on KindOfStaticString vs. KindOfString.
auto const bothBoxed = curType.isBoxed() && newType.isBoxed();
auto const sameUnboxed =
curType.isSameKindOf(newType) && !curType.isString();
if (bothBoxed || sameUnboxed) {
inst->setOpcode(StLocNT);
}
return nullptr;
}
bool TraceBuilder::shouldConstrainGuards() const {
return RuntimeOption::EvalHHIRRelaxGuards &&
!inReoptimize();
}