https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101956
Bug ID: 101956
Summary: Miss vectorization from v4hi to v4df
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: crazylht at gmail dot com
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-*-* i?86-*-*
void
foo (double* p, short* q)
{
p[0] = q[0];
p[1] = q[1];
p[2] = q[2];
p[3] = q[3];
}
clang generates
vpmovsxwd xmm0, qword ptr [rsi]
vcvtdq2pd ymm0, xmm0
vmovups ymmword ptr [rdi], ymm0
vzeroupper
gcc generates
foo(double*, short*):
movswl (%rsi), %eax
vxorps %xmm0, %xmm0, %xmm0
vcvtsi2sdl %eax, %xmm0, %xmm1
movswl 2(%rsi), %eax
vcvtsi2sdl %eax, %xmm0, %xmm2
movswl 4(%rsi), %eax
vmovsd %xmm2, %xmm2, %xmm3
vcvtsi2sdl %eax, %xmm0, %xmm2
movswl 6(%rsi), %eax
vcvtsi2sdl %eax, %xmm0, %xmm0
vunpcklpd %xmm0, %xmm2, %xmm2
vunpcklpd %xmm3, %xmm1, %xmm0
vinsertf128 $0x1, %xmm2, %ymm0, %ymm0
vmovupd %ymm0, (%rdi)
vzeroupper
ret
