bool IRBuilder::constrainLocal(uint32_t locId, SSATmp* typeSrc,
TypeConstraint tc,
const std::string& why) {
if (!shouldConstrainGuards()) return false;
always_assert(IMPLIES(tc.innerCat > DataTypeGeneric,
tc.category >= DataTypeCountness));
ITRACE(1, "constrainLocal({}, {}, {}, {})\n",
locId, typeSrc ? typeSrc->inst()->toString() : "null", tc, why);
Indent _i;
if (!typeSrc) return false;
if (!typeSrc->isA(Type::FramePtr)) {
return constrainValue(typeSrc, tc);
}
// When typeSrc is a FramePtr, that means we loaded the value the local had
// coming into the trace. Trace through the FramePtr chain, looking for a
// guard for this local id. If we find it, constrain the guard. If we don't
// find it, there wasn't a guard for this local so there's nothing to
// constrain.
auto guard = guardForLocal(locId, typeSrc);
while (guard) {
if (guard->is(AssertLoc)) {
// If the refined type of the local satisfies the constraint we're
// trying to apply, we can stop here. This can happen if we assert a
// more general type than what we already know. Otherwise we need to
// keep tracing back to the guard.
if (typeFitsConstraint(guard->typeParam(), tc)) return false;
guard = guardForLocal(locId, guard->src(0));
} else {
assert(guard->is(GuardLoc, CheckLoc));
ITRACE(2, "found guard to constrain\n");
return constrainGuard(guard, tc);
}
}
ITRACE(2, "no guard to constrain\n");
return false;
}
void TraceBuilder::constrainLocal(uint32_t locId, SSATmp* valSrc,
TypeConstraint tc,
const std::string& why) {
if (!shouldConstrainGuards()) return;
FTRACE(1, "constrainLocal({}, {}, {}, {})\n",
locId, valSrc ? valSrc->inst()->toString() : "null", tc, why);
if (!valSrc) return;
if (!valSrc->isA(Type::FramePtr)) {
constrainValue(valSrc, tc);
return;
}
// When valSrc is a FramePtr, that means we loaded the value the local had
// coming into the trace. Trace through the FramePtr chain, looking for a
// guard for this local id. If we find it, constrain the guard. If we don't
// find it, there wasn't a guard for this local so there's nothing to
// constrain.
auto guard = guardForLocal(locId, valSrc);
while (guard) {
if (guard->is(AssertLoc)) {
// If the refined the type of the local satisfies the constraint we're
// trying to apply, we can stop here. This can happen if we assert a
// more general type than what we already know. Otherwise we need to
// keep tracing back to the guard.
if (typeFitsConstraint(guard->typeParam(), tc.category)) return;
guard = guardForLocal(locId, guard->src(0));
} else {
assert(guard->is(GuardLoc, AssertLoc));
FTRACE(2, " - found guard to constrain\n");
constrainGuard(guard, tc);
return;
}
}
FTRACE(2, " - no guard to constrain\n");
}
