https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94981
--- Comment #3 from Tony Reix <tony.reix at atos dot net> --- (In reply to Andreas Schwab from comment #1) > Converting a negative float to an unsigned integer is undefined. Yes, I do see some comments about this in older GCC bugs. Like: https://gcc.gnu.org/legacy-ml/gcc/2016-02/msg00373.html Moreover, I see that this option could help: -fsanitize=float-cast-overflow . However, I have 4 comments: - GCC on Fedora/x86_64 has made a choice (not forcing a 0 for negative values) that seems coherent. Why not makes the same choice everywhere in order to improve the portability? - GCC on Fedora/Power has made different choices for: (float, double, long double) vs (long double) against: (char, unsigned char, unsigned short, unsigned int). This looks incoherent. And the choice made for "long double" --> "unsigned long" looks like a true bug. - Since that was working differently with GCC v6.3 on AIX vs GCC v8 & 9 on AIX, that looks like a regression. - Defect https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84154 deals with the same kind of issue, appearing in GCC 7, I think. And it was accepted and fixed. However, it seems that only 1 patch out of 2 has been pushed.
