https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109944
--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
> I think we can go and for a generic V16QImode CTOR and SSE2 create two
> V8HImode vectors using pinsrw, for the first from zero-extended QImode
> values of the even elements and for the second from zero-extended and
> left-shifted values of the odd elements and then IOR the two vectors.
Or the backend can recognize as as a HImode(b,c) broadcast + HImode(d,e)
vec_set(the middle end can recognize it as VEC_DUPLICATE_EXPR +
.VEC_SET/BIT_INSERT_EXPR when available?)
void foo1(short* a, char *m)
{
char d = *m;
char e = m[2];
short b = d | e << 8;
a[0] = b;
a[1] = b;
a[2] = b;
a[3] = b;
a[4] = b;
a[5] = b;
a[6] = b;
a[7] = b;
}
foo1:
movsbw 2(%rsi), %ax
movsbw (%rsi), %dx
sall $8, %eax
orl %edx, %eax
movd %eax, %xmm0
punpcklwd %xmm0, %xmm0
pshufd $0, %xmm0, %xmm0
movups %xmm0, (%rdi)
ret
