[Bug middle-end/64225] -funsafe-math-optimizations generates call to pow where multiply instruction would do

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64225

--- Comment #4 from ktkachov at gcc dot gnu.org ---
Add -fno-math-errno removes the call to pow. We've seen similar issues before
with other math builtins. The problem is that the midend/frontend generates the
pow call without remembering that by doing so it should assume that the
multiplication cannot set errno