Re: [PATCH] Use -mskip-rax-setup if supported

[Andi Kleen]

On Thu, Apr 16, 2015 at 02:23:44PM -0700, H.J. Lu wrote:
> GCC 5 added a compiler option, -mskip-rax-setup, for x86-64.  It skips
> setting up the RAX register when SSE is disabled and there are no
> variable arguments passed in vector registers.  Since kernel doesn't
> pass vector registers to functions with variable arguments, this option
> can be used to optimize the x86-64 kernel.  For kernel 3.17:
> 
>     text   data    bss    dec      hex   filename
> 11455921 2204048 5853184 19513153 129bf41 vmlinux #with -mskip-rax-setup
> 11480079 2204048 5853184 19537311 12a1d9f vmlinux

Patch looks good to me.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

-Andi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/