Re: ARM EABI port: minimum CPU choice
On Mon, 2006-06-12 at 23:54 +0200, Martin Guy wrote:
> > It will use mov pc, lr.
> >
> > There are at least three places that need fixing:
> > - Function returns
> > - Indirect calls
> > - Assembly code in libgcc.
> >
> > glibc would also need auditing for problematic assembly code.
>
> Is there any reason not to make ldm the default for armv4 and above,
> since it seems to win most, among the various options?
Two reasons: because it requires the return address to be on the stack
(which often requires adding another instruction to get it there), and
because LDM is quite a slow instruction on Intel CPUs. That said, in
the specific case of Debian it's possible that these disadvantages are
outweighed by the compatibility benefits.
p.
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