Floating-point comparisons in the middle-end

[FX]

Hi Jakub,

>> 2.  All the functions are available as GCC type-generic built-ins (yeah!),
>> except there is no __builtin_ iseqsig
>> (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77928).  Is there a
>> fundamental problem with creating one, and could someone help there?
> 
> IMHO until that one is implemented you can just use
> tx = x, ty = y, tx>=ty && tx<=ty
> (in GENERIC just SAVE_EXPR<x> >= SAVE_EXPR<y> && SAVE_EXPR<x> <= SAVE_EXPR<y>

If it’s just that (optimization aside), I probably can create a C built-in. It would need to be:

1. defined in builtins.def
2. lowered in builtins.cc
3. type-checked in c-family/c-common.cc
4. documented in doc/extend.texi
5. tested in fp-test.cc
6. covered in the testsuite

Is that right?

Thanks,
FX


PS: I see that reclassify is not covered in fp-test.cc, is that file obsolete?