[Bug rtl-optimization/47477] [4.6/4.7/4.8/4.9 regression] Sub-optimal mov at end of method

[tony.poppleton at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47477



--- Comment #13 from Tony Poppleton <tony.poppleton at gmail dot com> 
2013-04-10 01:44:18 UTC ---

The test case appears to be fixed in GCC 4.8.0, compiling with just -S and -O3,

the asm

output is now a much simpler:



        .file   "test.c"

        .text

        .p2align 4,,15

        .globl  add

        .type   add, @function

add:

.LFB0:

        .cfi_startproc

        andq    $-2, %rsi

        leaq    (%rdi,%rsi), %rax

        ret

        .cfi_endproc

.LFE0:

        .size   add, .-add

        .ident  "GCC: (GNU) 4.8.0 20130316 (Red Hat 4.8.0-0.17)"

        .section        .note.GNU-stack,"",@progbits



I don't know if other test cases would reproduce the original bug however.