https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112449
--- Comment #9 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- To quote the C23 DIS, "This annex does not require the full support for signaling NaNs specified in IEC 60559. This annex uses the term NaN, unless explicitly qualified, to denote quiet NaNs.". Support for signaling NaNs is indicated by FE_SNANS_ALWAYS_SIGNAL in <fenv.h>, which glibc makes sure to define only if __SUPPORT_SNAN__ (which is defined by GCC if -fsignaling-nans). If -fsignaling-nans is not used, you should not expect consistency in whether a signaling NaN is handled differently from a quiet NaN (including whether optimizations might be applied that result in a signaling NaN result from an operation that can't produce such a result with IEEE signaling NaN semantics).
