SSATmp* IRInstruction::previousStkPtr() const {
assert(modifiesStack());
assert(MInstrEffects::supported(this));
auto base = src(minstrBaseIdx(this));
assert(base->inst()->is(LdStackAddr));
return base->inst()->src(0);
}
void MInstrEffects::get(const IRInstruction* inst,
const FrameStateMgr& frame,
LocalStateHook& hook) {
// If the base for this instruction is a local address, the helper call might
// have side effects on the local's value
auto const base = inst->src(minstrBaseIdx(inst->op()));
auto const locInstr = base->inst();
// Right now we require that the address of any affected local is the
// immediate source of the base tmp. This isn't actually specified in the ir
// spec right now but will intend to make it more general soon.
if (locInstr->op() != LdLocAddr) return;
auto const locId = locInstr->extra<LdLocAddr>()->locId;
auto const baseType = frame.localType(locId);
MInstrEffects effects(inst->op(), baseType.ptr(Ptr::Frame));
if (effects.baseTypeChanged || effects.baseValChanged) {
auto const ty = effects.baseType.derefIfPtr();
if (ty.isBoxed()) {
hook.setLocalType(locId, Type::BoxedInitCell);
hook.setBoxedLocalPrediction(locId, ty);
} else {
hook.setLocalType(locId, ty);
}
}
}
