https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95921
--- Comment #1 from Rich Felker <bugdal at aerifal dot cx> ---
I wonder if the fact that GCC thinks the output of the insn is already double
suggests other similar bugs in the m68k backend, though... If extended
precision were working correctly, I'd think it would at least expect the result
to have extended precision and be trying to drop the excess precision
separately. But it's not; it's just returning. Here's my test case:
double my_sqrt(double x)
{
return __builtin_sqrt(x);
}
with -O2 -std=c11 -fno-math-errno -fomit-frame-pointer
The last 2 options are non-critical (GCC still uses the inline insn even with
-fmath-errno and branches only for the exceptional case) but clean up the
output so it's more clear what's going on.
