Type getOptimisticType(final Optimistic node) {
assert compiler.useOptimisticTypes();
final int programPoint = node.getProgramPoint();
final Type validType = compiler.getInvalidatedProgramPointType(programPoint);
if (validType != null) {
return validType;
}
final Type mostOptimisticType = node.getMostOptimisticType();
final Type evaluatedType = getEvaluatedType(node);
if (evaluatedType != null) {
if (evaluatedType.widerThan(mostOptimisticType)) {
final Type newValidType =
evaluatedType.isObject() || evaluatedType.isBoolean() ? Type.OBJECT : evaluatedType;
// Update invalidatedProgramPoints so we don't re-evaluate the expression next time. This is
// a heuristic
// as we're doing a tradeoff. Re-evaluating expressions on each recompile takes time, but it
// might
// notice a widening in the type of the expression and thus prevent an unnecessary
// deoptimization later.
// We'll presume though that the types of expressions are mostly stable, so if we evaluated
// it in one
// compilation, we'll keep to that and risk a low-probability deoptimization if its type
// gets widened
// in the future.
compiler.addInvalidatedProgramPoint(node.getProgramPoint(), newValidType);
}
return evaluatedType;
}
return mostOptimisticType;
}
private static Type computeElementType(final Expression[] value) {
Type widestElementType = Type.INT;
for (final Expression elem : value) {
if (elem == null) {
widestElementType =
widestElementType.widest(Type.OBJECT); // no way to represent undefined as number
break;
}
final Type type = elem.getType().isUnknown() ? Type.OBJECT : elem.getType();
if (type.isBoolean()) {
// TODO fix this with explicit boolean types
widestElementType = widestElementType.widest(Type.OBJECT);
break;
}
widestElementType = widestElementType.widest(type);
if (widestElementType.isObject()) {
break;
}
}
return widestElementType;
}