Especially as the ABI states that the write of the backlink
and the stack pointer update _have_ to be done in one insn.
That's on allocation. Deallocation isn't so critical. You just need
to
ensure the backchain is written before updating sp.
Yes, but your example generated code showed all
On Tue, Sep 13, 2005 at 11:28:07AM +0200, Segher Boessenkool wrote:
> Especially as the ABI states that the write of the backlink
> and the stack pointer update _have_ to be done in one insn.
That's on allocation. Deallocation isn't so critical. You just need to
ensure the backchain is written b
On 10 sep 2005, at 02:03, Richard Henderson wrote:
On Sat, Sep 10, 2005 at 01:00:04AM +0930, Alan Modra wrote:
2) Next, I defined parallels to keep things together. Like the
following, with another for DImode.
This seems most reasonable to me.
Especially as the ABI states that the write o
On Sat, Sep 10, 2005 at 12:57:49PM +0930, Alan Modra wrote:
> Also stack deallocation when finished with alloca memory.
Ah.
> For some reason 4.0/4.1 doesn't combine this deallocation with
> stack adjustment in the epilogue, a regression from 3.4.
Yeah, I've been meaning to write a pass that goe
On Fri, Sep 09, 2005 at 05:03:48PM -0700, Richard Henderson wrote:
> On Sat, Sep 10, 2005 at 01:00:04AM +0930, Alan Modra wrote:
> > 2) Next, I defined parallels to keep things together. Like the
> > following, with another for DImode.
>
> This seems most reasonable to me.
>
> > This works, but
On Sat, Sep 10, 2005 at 01:00:04AM +0930, Alan Modra wrote:
> 2) Next, I defined parallels to keep things together. Like the
> following, with another for DImode.
This seems most reasonable to me.
> This works, but doesn't give ideal power4/5 insn grouping, with (I
> think) one too many nops bei
PR23774 shows a situation where powerpc-linux (and other rs6000 targets)
break an ABI requirement that 0(r1) always holds a pointer to the
previous stack frame, except for the topmost frame. This particular
case concerns dynamic stack (eg. alloca) deallocation. The other case
where this happens i
