Re: PATCH: PR target/24419: ix86 prologue clobbers memory when it shouldn't

[Richard Henderson <rth at redhat dot com>]

On Tue, Oct 18, 2005 at 08:57:14PM -0700, H. J. Lu wrote:
> clobber_memory == false is when we call pro_epilogue_adjust_stack
> after registers have been saved on stack:
...
>     pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,
> 			       GEN_INT (-allocate), -1, !using_mov);
> 
> Is there anything wrong?

Yes.  I'll say this one more time, loudly:

            USING MOVE OR PUSH HAS NOTHING TO DO WITH WHETHER
                         THE CLOBBER IS NEEDED

It has everything to do with whether a frame pointer is used,
and blocking memory references from crossing the allocation
boundary.

I've yet to even hear you *pretend* to defend the correctness
of the changes in your patch.  You have no idea why you're doing
what you're doing, do you?  You've simply got "clobber bad"
running through your head and you're blindly attacking everything
containing "clobber".

Do not, as you are wont to do, re-post 15 more versions with
"fixed typos" until you address the core problems.  Preferably
by listening to me instead of ignoring me.


r~