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
>
>
> --
> H.J.
> From a759c1a4f6ffa408d49e1959449d6797769b951e Mon Sep 17 00:00:00 2001
> From: "H.J. Lu" <hjl.to...@gmail.com>
> Date: Wed, 17 Dec 2014 18:05:29 -0800
> Subject: [PATCH] Use -mskip-rax-setup if supported
>
> 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
>
> Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
Applied, thanks.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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