From: Andi Kleen <ak@suse.de>
To: Dave Jones <davej@redhat.com>
Subject: Re: [PATCH] [20/45] x86_64: Use 8 byte stack alignment when possible
Date: Sat, 22 Sep 2007 00:34:31 +0200
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References: <200709211044.901175000@suse.de> <20070921204502.2C61D14EFF@wotan.suse.de> <20070921211341.GC8127@redhat.com>
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On Friday 21 September 2007 23:13, Dave Jones wrote:
> On Fri, Sep 21, 2007 at 10:45:02PM +0200, Andi Kleen wrote:
>  > Kernel doesn't use SSE2, so it doesn't need 16 byte alignment. Also
>  > the stack can be already unaligned so letting the compiler align
>  > is useless. This may make some stack frames smaller.
>  > Only works with very recent gcc 4.3
>
> My gcc 4.1.2 from Fedora 7 (with who knows what backported)
> references this in its manpage. How was it broken before 4.3 ?

Try it. It is rejected by the compiler in 64bit mode.

-Andi
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