Re: [Qemu-devel] X86_64 (AMD64) build segfaults

[Paul Brook <paul@codesourcery.com>]

On Friday 22 April 2005 17:12, Jonas Maebe wrote:
> On 22 apr 2005, at 17:41, developer@isl-gbr.de wrote:
> > Hello Jonas, here is the output of the command you gave me for this
> > function, does this help ?
>
> It helps in the sense that it confirms my suspicion, although I don't
> know why it creates such convoluted code. Maybe in order to have as
> small code as possible with at the same time as many aligned jump
> targets as possible. It's definitely not trivial to parse this, and
> even less trivial to rewrite it so it is usable for qemu's purposes (in
> this particular case, the retq could be replaced by a jmp, but you
> can't count on there being 4 padding bytes after each ret).
>
> You (or someone else) will have to find a way to force gcc 4.0 to put
> one ret (or jump) at the very end of the code it generates. If that's
> not possible, it will be quite hard to support gcc 4.0 in qemu...

It's not possible to force gcc4 to put the "ret" at the end of the code.

Paul