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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] qemu vs gcc4
Date: Mon, 23 Oct 2006 18:58:29 +0100
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To: qemu-devel@nongnu.org

On Monday 23 October 2006 18:41, K. Richard Pixley wrote:
> Martin Guy wrote:
> >> Now, gcc4 can produce code with several return instructions (with no
> >> option to turn that of, as far as I understand). You cannot cut them
> >> out,
> >> and therefore you cannot chain the simple functions.
> >
> > ...unless you also map return instructions within the generated
> > functions into branches to the soon-to-be-dropped final "return"? Not
> > that I know anything about qemu internals mind u...
>
> Seems to me one could also map them into jumps to a null function.

That doesn't work because you need to free the stack frame.

> Although, all told, it would seem to me that what might be called for
> here is a new gcc target.  A gcc target specifically for generating qemu
> code.  That would just simply generate whatever qemu wanted for function
> postamble.

Better to just teach qemu how to generate code.
In fact I've already done most of the infrastructure (and a fair amount of the 
legwork) for this. The only major missing function is code to do softmmu 
load/store ops.
https://nowt.dyndns.org/

Paul