[Bug middle-end/93806] Wrong optimization: instability of floating-point results with -funsafe-math-optimizations leads to nonsense

[vincent-gcc at vinc17 dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93806

--- Comment #39 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
So I wonder whether -fno-signed-zeros should be removed. It seems too
dangerous. The -ffinite-math-only option is fine because the programmer may be
able to prove that Inf and NaN never occur in his code (at least with
non-erroneous inputs). But zero is a value that is too common, and not having a
very rigorous specification for -fno-signed-zeros is bad.

Now, if the only issue with -fno-signed-zeros (assuming division by 0 does not
occur) concerns values with multiple representations, solving this more general
issue could be sufficient, though.