https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97352
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
So a simpler testcase is the following (but hinting at the possibly not generic
enough solution to split the load group):
double a[6], b[6];
void foo()
{
a[0] = b[0];
a[1] = b[1];
a[2] = b[2];
a[3] = b[3];
a[4] = b[4];
a[5] = b[5];
}
produces with SSE:
movapd b(%rip), %xmm0
movapd b+16(%rip), %xmm1
movapd b+32(%rip), %xmm2
movaps %xmm0, a(%rip)
movaps %xmm1, a+16(%rip)
movaps %xmm2, a+32(%rip)
and with AVX:
vmovsd b+32(%rip), %xmm0
vmovapd b(%rip), %ymm1
vmovsd %xmm0, a+32(%rip)
vmovsd b+40(%rip), %xmm0
vmovapd %ymm1, a(%rip)
vmovsd %xmm0, a+40(%rip)
while we'd like to see sth like
vmovapd b(%rip), %ymm1
vmovapd %ymm1, a(%rip)
movapd b+32(%rip), %xmm2
movaps %xmm2, a+32(%rip)
