https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113576
--- Comment #36 from Richard Biener <rguenth at gcc dot gnu.org> ---
For example with AVX512VL and the following, using -O -fgimple -mavx512vl
we get simply
notl %esi
orl %esi, %edi
cmpb $15, %dil
je .L6
typedef long v4si __attribute__((vector_size(4*sizeof(long))));
typedef v4si v4sib __attribute__((vector_mask));
typedef _Bool sbool1 __attribute__((signed_bool_precision(1)));
void __GIMPLE (ssa) foo (v4sib v1, v4sib v2)
{
v4sib tem;
__BB(2):
tem_5 = ~v2_2(D);
tem_3 = v1_1(D) | tem_5;
tem_4 = _Literal (v4sib) { _Literal (sbool1) -1, _Literal (sbool1) -1,
_Literal (sbool1) -1, _Literal (sbool1) -1 };
if (tem_3 == tem_4)
goto __BB3;
else
goto __BB4;
__BB(3):
__builtin_abort ();
__BB(4):
return;
}
the question is whether that matches the semantics of GIMPLE (the padding
is inverted, too), whether it invokes undefined behavior (don't do it - it
seems for people using intrinsics that's what it is?) or whether we
should avoid affecting padding.
Note after the patch I proposed on the mailing list the constant mask is
now expanded with zero padding.
