[Bug middle-end/102877] missed optimization: memcpy produces lots more asm than otherwise

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102877

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |fixed-but-no-testcase,
                   |                            |needs-bisection

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
`-DWITH_MEMCPY -O2` case is fixed on the trunk (for both aarch64 and x86_64
similarlly):
```
gc_to_num(GLOBCNT):
.LFB0:
        .cfi_startproc
        movq    %rdi, %rax
        salq    $16, %rax
        bswap   %rax
        ret
```

I don't know what fixed it either.

-UWITH_MEMCPY -O2 gives:
```
        movl    %edi, %eax
        shrq    $32, %rdi
        salq    $48, %rdi
        salq    $16, %rax
        orq     %rdi, %rax
        bswap   %rax
```