https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54192
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rguenth at gcc dot gnu.org
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
flag_trapping_math also guards things like
/* Don't perform operation if it would raise a division
by zero exception. */
if (code == RDIV_EXPR
&& real_equal (&d2, &dconst0)
&& (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
return NULL_TREE;
so I guess it differs from -frounding-math also in a way that it doesn't
guard FENV access of the exception state (I'd say that is not implemented
at all, not even in the -frounding-math way) but it guards whether
the FENV state is set to trap? So its default should match the
execution environments default?
So IMHO we should simply document that -frounding-math is about
FENV access (including exception bits) and -fno-trapping-math is
about "exceptions" in the C++ sense (aka traps).
