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Re: Initial shrink-wrapping patch


On Thu, Oct 6, 2011 at 11:40 AM, Bernd Schmidt <bernds@codesourcery.com> wrote:
> 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?

X32 has 32bit software stack pointer and 64bit hardware stack
pointer.

> 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?
>

It should be covered by SP.

-- 
H.J.


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