Initial shrink-wrapping patch

[Bernd Schmidt]

On 10/06/11 20:27, H.J. Lu wrote:
> It also caused:
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50633
> 
> Don't you need to update ix86_expand_prologue?

In theory it should just work. It seems the x32 stuff has entertaining
properties :-( Haven't quite figured out how to build it yet, but:

-    subq    $136, %rsp
-    .cfi_def_cfa_offset 144
     movl    $0, %eax
     movl    %esp, %ecx
     addl    $60, %ecx
@@ -16,6 +14,8 @@ main:
     movl    %eax, (%edx)
     cmpl    $16, %eax
     jne    .L2
+    subq    $136, %rsp
+    .cfi_def_cfa_offset 144

So, this looks like we have both $esp and $rsp - i.e. not using
stack_pointer_rtx in all cases? Is there a way to avoid this?

BTW, one other thing that occurred to me - what about drap_reg? Does
that need to be added to the set of registers whose use requires a prologue?


Bernd