https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87743
--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> --- (In reply to Andrew Pinski from comment #4) > Even for x86_64: > vmovdqa src(%rip), %xmm0 > vpmovsxdq %xmm0, %xmm1 > vpsrldq $8, %xmm0, %xmm0 > vpmovsxdq %xmm0, %xmm0 > vmovaps %xmm1, dst(%rip) > vmovaps %xmm0, 16+dst(%rip) > ret Only when AVX2 is disabled.