https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123987
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to lukewang from comment #3) > https://man7.org/linux/man-pages/man3/finite.3.html > The isinf(), isinff(), and isinfl() functions return 1 if x is > positive infinity, -1 if x is negative infinity, and 0 otherwise. > > Why is this behavior inconsistent with that in the Linux manual? It's consistent with C99 requirements. Possibly POSIX requires the negative return value, but I didn't check.
