The generic implementation of fetestexceptflag does:
int
fetestexceptflag (const fexcept_t *flagp, int excepts)
{
/* Most versions of fegetexceptflag store exceptions in a form such
that this works. */
return *flagp & excepts & FE_ALL_EXCEPT;
}
In the case where FE_ALL_EXCEPT is nonzero but exceptions may not be
supported at runtime, this only works if fegetexceptflag cleared all
the bits of FE_ALL_EXCEPT in *flagp; otherwise it accesses
uninitialized data. This showed up as a failure of
math/test-fetestexceptflag for MIPS o32 soft-float. This patch makes
the fallback fegetexceptflag store 0 (fexcept_t is an integer type
everywhere) so that this works. (No bug report in Bugzilla because
this wasn't user-visible - at least, without using tools to detect
uninitialized memory use at runtime - without fetestexceptflag, which
is new in 2.25.)
Tested for MIPS o32 soft-float.
* math/fgetexcptflg.c (__fegetexceptflag): Store 0 in fexcept_t
object.
Joseph Myers
Allan McRae
Thomas Schwinge
Paul Eggert
Ulrich Drepper
Jakub Jelinek