> On May 11, 2015, at 6:16 PM, Thiago Farina <tfrans...@gmail.com> wrote:
>
> Hi,
>
> Clang 3.7 generated the following code:
>
> $ clang -S -O0 -fno-unwind-tables -fno-asynchronous-unwind-tables
> add.c -o add_att_x64.s
>
> add:
> pushq %rbp
> movq %rsp, %rbp
> movl %edi, -4(%rbp)
> movl %esi, -8(%rbp)
> movl -4(%rbp), %esi
> addl -8(%rbp), %esi
> movl %esi, %eax
> popq %rbp
> retq
>
> While gcc 4.8 generated the following:
>
> $ gcc -S -O0 -fno-unwind-tables -fno-asynchronous-unwind-tables add.c
> -o add_att_x64.s
>
> add:
> pushq %rbp
> movq %rsp, %rbp
> movl %edi, -4(%rbp)
> movl %esi, -8(%rbp)
> movl -8(%rbp), %eax
> movl -4(%rbp), %edx
> addl %edx, %eax
> popq %rbp
> ret
>
> $ cat add.c
> int add(int a, int b) {
> return a + b;
> }
>
> Is the clang version better?
Neither is better or worse due to this is at -O0.
Thanks,
Andrew
>
> --
> Thiago Farina
