https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123870
--- Comment #11 from Ilya Kurdyukov <jpegqs at gmail dot com> ---
I tried gcc-16, ICE (validate_change_or_fail) disappeared.
> gcc version 16.0.0 20251214 (experimental)
> [trunk r16-6108-g427ddf95eef] (Debian 16-20251214-1)
There are still some places that give incorrect results.
I have the following code:
if (condition == true) {
#if RVV_PATH1
RVV code here
#else
scalar code here
#endif
} else {
// exit(1);
#if RVV_PATH2
RVV code here
#else
scalar code here
#endif
}
condition == true, RVV_PATH1 = 1, RVV_PATH2 = 1 -> result has artifacts
condition == true, RVV_PATH1 = 1, RVV_PATH2 = 0 -> result looks correct
This means that the RVV code for the "condition == false" path breaks the RVV
code for the "condition == true" path, even if it isn't executed during run.
When I uncomment the line with exit(1), the result looks correct but is
slightly different (file hash differs from build with RVV_PATH2 = 0).
After compilation, three runs are made, and all the results is the same (same
file hash), there is no randomness at runtime: same input = same output.
This is image processing using floating point calculations, fused multiply-add
and the order in which floating point sums are calculated - may slightly change
the result, but will not create visible artifacts.
