Re: [Chicken-hackers] [PATCH] Mostly fix #1604

[megane]

address@hidden writes:

>> > Shouldn't the types.db specialization for scheme#= be applied
>> > here? Or can't it figure out the ffixnum types of the arguments?
>> > Even though it is slightly dangerous, the scrutinizer _could_ assume
>> > arguments to numerical primitives are fixnums in fixnum mode...
>>
>> That's right, the scrutinizer can't figure out the types. The type of n
>> for the first scheme#= call is *. The call enforces the type to number.
>> So the second scheme#= is called with (number fixnum). There's no
>> specialization for that either.
>>
>> Wouldn't that kind of assuming lead to hard to debug bugs?
>
> Yes, that danger is indeed not to be ignored.
>
>>
>> If the scrutinizer could infer types for functions then I think that
>> would be fine. You'd get a warning somewhere.
>
> Interprocedural flow-analysis is hard, we shouldn't underestimate
> this. What happens when we declare a type for a toplevel function?

If you're thinking about reassigning globals, how about making
-fixnum-arithmetic imply -local? If globals cannot be re-defined then
the types are always correct.

If fixnum-arithmetic is wanted for speed then -local is wanted anyway,
not to mention global inlining.


>
>
> felix