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From: "liuhongt at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/92080] Missed CSE of _mm512_set1_epi8(c) with
 _mm256_set1_epi8(c)
Date: Thu, 21 Mar 2024 07:13:59 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D92080

Hongtao Liu <liuhongt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |liuhongt at gcc dot gnu.org

--- Comment #7 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
Another simple case is=20

typedef int v4si __attribute__((vector_size(16)));
typedef short v8hi __attribute__((vector_size(16)));

v8hi a;
v4si b;
void
foo ()
{
   b =3D __extension__(v4si){0, 0, 0, 0};
   a =3D __extension__(v8hi){0, 0, 0, 0, 0, 0, 0, 0};
}

GCC generates 2 pxor

foo():
        vpxor   xmm0, xmm0, xmm0
        vmovdqa XMMWORD PTR b[rip], xmm0
        vpxor   xmm0, xmm0, xmm0
        vmovdqa XMMWORD PTR a[rip], xmm0
        ret=