[Bug rtl-optimization/118623] [12/13/14/15 regression] Miscompile with -O2/3 and -O0/1 since r12-7751-g919fbffef07555

[liuhongt at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118623

--- Comment #17 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #15)
> Created attachment 60411 [details]
> gcc15-pr118623.patch
> 
> Untested patch which seems to work for me on the new testcases and
> i386.exp=bt*.c so far.

When there's a borrow, Carry flag is set. swap operands order to (compare:CCC
(const_int 0) (zero_extract ...)) looks like a good idea.