https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88828
H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |crazylht at gmail dot com, | |xuepeng.guo at intel dot com --- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> --- Another testcase: [hjl@gnu-cfl-1 pr88828]$ cat y.i typedef double __v2df __attribute__ ((__vector_size__ (16))); typedef double __m128d __attribute__ ((__vector_size__ (16), __may_alias__)); __m128d _mm_add_sd (__m128d x, __m128d y) { __m128d z = __extension__ (__m128d)(__v2df) { (((__v2df) x)[0] + ((__v2df) y)[0]), ((__v2df) x)[1] }; return z; } [hjl@gnu-cfl-1 pr88828]$ gcc -S -O2 y.i [hjl@gnu-cfl-1 pr88828]$ cat y.s .file "y.i" .text .p2align 4,,15 .globl _mm_add_sd .type _mm_add_sd, @function _mm_add_sd: .LFB0: .cfi_startproc movapd %xmm0, %xmm2 addsd %xmm1, %xmm2 movsd %xmm2, %xmm0 ret .cfi_endproc .LFE0: .size _mm_add_sd, .-_mm_add_sd .ident "GCC: (GNU) 8.2.1 20190109 (Red Hat 8.2.1-7)" .section .note.GNU-stack,"",@progbits [hjl@gnu-cfl-1 pr88828]$ I am expecting addsd %xmm1, %xmm0 retq