Work around GCC bug in generating 64-bit population of SSE register

We know what code we want it to generate, so I just replaced the
_mm_set1_epi64x() with the code we want it to generate. Except that GCC
sees through and tries to "optimize" my code... so that asm() statement
makes it separate the two operations.

This generates optimal code for both 32- and 64-bit.  64-bit:
        vmovq   %rdi, %xmm0
        vpbroadcastq    %xmm0, %ymm0
32-bit:
        vmovq   8(%esp), %xmm0
        vpbroadcastq    %xmm0, %ymm0

See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80820 and
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87976

Change-Id: I42a48bd64ccc41aebf84fffd15664109b97fe42b
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

0 files changed, 0 insertions, 0 deletions