https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89229
--- Comment #16 from H.J. Lu <hjl.tools at gmail dot com> ---
[hjl@gnu-4 gcc]$ cat /tmp/y.c
/* { dg-do compile { target { ! ia32 } } } */
/* { dg-options "-O2 -march=skylake-avx512 -mprefer-vector-width=512" } */
extern float d;
void
foo1 (float x)
{
register float xmm16 __asm ("xmm16") = x;
asm volatile ("" : "+v" (xmm16));
d = xmm16;
}
/* { dg-final { scan-assembler-not "%zmm\[0-9\]+" } } */
[hjl@gnu-4 gcc]$ gcc -S -O2 -march=skylake-avx512 /tmp/y.c
-mprefer-vector-width=512
[hjl@gnu-4 gcc]$ cat y.s
.file "y.c"
.text
.p2align 4,,15
.globl foo1
.type foo1, @function
foo1:
.LFB0:
.cfi_startproc
vmovaps %zmm0, %zmm16
vmovss %xmm16, d(%rip)
ret
.cfi_endproc
.LFE0:
.size foo1, .-foo1
.ident "GCC: (GNU) 8.2.1 20190209 (Red Hat 8.2.1-8)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-4 gcc]$
