https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64909
H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2015-02-02 Ever confirmed|0 |1 --- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> --- Today's mainline generates: movzwl a+16(%rip), %eax pxor %xmm1, %xmm1 movdqa a(%rip), %xmm0 movdqa %xmm0, %xmm2 movl %eax, b+32(%rip) movzwl a+18(%rip), %eax punpcklwd %xmm1, %xmm2 punpckhwd %xmm1, %xmm0 movl %eax, b+36(%rip) movzwl a+20(%rip), %eax movaps %xmm2, b(%rip) movaps %xmm0, b+16(%rip) movl %eax, b+40(%rip) movzwl a+22(%rip), %eax movl %eax, b+44(%rip) ret at -O3.