https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85048
--- Comment #12 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Hongtao.liu from comment #9)
> With the patch, we can generate optimized code expect for those 16 {u,}qq
> cases, since the ABI doesn't support 1024-bit vector.
Can't these be vectorized using partial vectors? GCC generates:
_Z9vcvtqq2psDv16_l:
vmovq 56(%rsp), %xmm0
vmovq 40(%rsp), %xmm1
vmovq 88(%rsp), %xmm2
vmovq 120(%rsp), %xmm3
vpinsrq $1, 64(%rsp), %xmm0, %xmm0
vpinsrq $1, 48(%rsp), %xmm1, %xmm1
vpinsrq $1, 96(%rsp), %xmm2, %xmm2
vpinsrq $1, 128(%rsp), %xmm3, %xmm3
vinserti128 $0x1, %xmm0, %ymm1, %ymm1
vcvtqq2psy 8(%rsp), %xmm0
vcvtqq2psy %ymm1, %xmm1
vinsertf128 $0x1, %xmm1, %ymm0, %ymm0
vmovq 72(%rsp), %xmm1
vpinsrq $1, 80(%rsp), %xmm1, %xmm1
vinserti128 $0x1, %xmm2, %ymm1, %ymm1
vmovq 104(%rsp), %xmm2
vcvtqq2psy %ymm1, %xmm1
vpinsrq $1, 112(%rsp), %xmm2, %xmm2
vinserti128 $0x1, %xmm3, %ymm2, %ymm2
vcvtqq2psy %ymm2, %xmm2
vinsertf128 $0x1, %xmm2, %ymm1, %ymm1
vinsertf64x4 $0x1, %ymm1, %zmm0, %zmm0
where clang manages to vectorize the function to:
vcvtqq2ps 16(%rbp), %ymm0
vcvtqq2ps 80(%rbp), %ymm1
vinsertf64x4 $1, %ymm1, %zmm0, %zmm0
