Re: [PATCH] [20/45] x86_64: Use 8 byte stack alignment when possible

Andi Kleen
2007-09-21T22:53:46Z

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