[Bug target/99621] [8/9/10/11 Regression] Wrong code with -m32 -O1 -fcaller-saves -fexpensive-optimizations since g:058e97ecf33ad0dfd926b3876a4bcf59ac9556ff

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99621

--- Comment #21 from Martin Liška <marxin at gcc dot gnu.org> ---
All right, I think it's a well-known problem called X87 FP unit.
The test-case is fixed with:

$ gcc pr99621-3.c -O2 -m32 && ./a.out
len 5167, expected bad
$ gcc pr99621-3.c -O2 -m32 -ffloat-store && ./a.out
len 4287, good
$ gcc pr99621-3.c -O2 -m32 -mfpmath=sse && ./a.out
len 4287, good