[Bug target/44551] [missed optimization] AVX vextractf128 after vinsertf128

[hjl dot tools at gmail dot com]

------- Comment #10 from hjl dot tools at gmail dot com  2010-06-28 19:17 
-------
Here is a small testcase:

[...@gnu-6 44551]$ cat c.s
        .file   "c.c"
        .text
        .p2align 4,,15
.globl foo
        .type   foo, @function
foo:
.LFB798:
        .cfi_startproc
        pushq   %rbp
        .cfi_def_cfa_offset 16
        vinsertf128     $0x1, %xmm1, %ymm0, %ymm0
        movq    %rsp, %rbp
        .cfi_offset 6, -16
        .cfi_def_cfa_register 6
        vextractf128    $0x1, %ymm0, %xmm0
        leave
        .cfi_def_cfa 7, 8
        ret
        .cfi_endproc
.LFE798:
        .size   foo, .-foo
        .ident  "GCC: (GNU) 4.6.0 20100625 (experimental)"
        .section        .note.GNU-stack,"",@progbits
[...@gnu-6 44551]$ 

The optimize code is

        vmovaps   %xmm1, %xmm0
        ret         


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44551