https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79173
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org
--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 55271
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55271&action=edit
gcc14-pr79173-wip.patch
Untested WIP (with backend implementation for x86 only so far).
Still, need to add/tweak some peephole2s to make pr79173-{1,2,3,4}.c tests
clean
on both x86-64 and i?86, and then as can be seen in pr79173-5.c need to do some
tweaks so that it pattern recognizes also the pattern recognized
__builtin_{add,sub}_overflow instead of those being used directly.
C23 is standardizing __builtin_{add,sub,mul}_overflow under the
ckd_{add,sub,mul} names, so pattern recognizing it that way is definitely
desirable.
Oh, and maybe incrementally check what happens if one of the addends or
subtrahends are immediate.
