This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] Fix optimization regression in constant folder


> But if that is the only justifieable property of sizetype, why not use a 
> type which naturally has this property, like some unsigned type?

Because there exist signed types that have that property too.

But I'm having trouble understanding what you're trying to do here.
Clearly we need the TYPE_IS_SIZETYPE flag and clearly the type must
be unique (for validity purposes, if nothing else).  So what we're talking
about is how we interpret the TYPE_IS_SIZETYPE flag.  I don't understand
why it has to be interpreted in terms of some *other* flags (ones that
are used for non-internal types).

> Depends on if you agree to the above or not.  If you agree (and you seem 
> to) that the important thing is wrapping overflow, I'm also going to say 
> that sizetype should not be allowed to be a signed type.

I *really* have a problem with purposely putting a negative value into an
unsigned type.  I think it's bad software engineering and completely
unnecessary.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]