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Re: [PING] 3 patches waiting for approval/review


On 10/10/13 18:41, Jeff Law wrote:
> On 10/10/13 04:00, Andreas Krebbel wrote:
>> On 09/10/13 21:46, Jeff Law wrote:
>>> On 08/21/13 03:21, Andreas Krebbel wrote:
>>>> [RFC] Allow functions calling mcount before prologue to be leaf functions
>>>> http://gcc.gnu.org/ml/gcc-patches/2013-04/msg00993.html
>>> I don't think this is necessarily correct for all targets.  ISTM the
>>> ability to consider a function calling mcount as a leaf needs to be a
>>> property of the target.
>>
>> We have already "profile_before_prologue" as a target property. Shouldn't this be enough to decide
>> upon this? When a function calls mcount before the prologue it shouldn't matter whether the function
>> is leaf or not.
> I don't think so, I think it'd break the PA's 32 bit ABI, maybe the 64 
> bit ABI as well.  It's the caller's responsibility to build a mini stack 
> frame if the function makes any calls.  If the code in the prologue 
> expander uses "leafness" to make the decision about whether or not to 
> allocate the mini frame, then it'd do the wrong thing here.
> 
> I'm just using that as an example, there may be others.  Hence my 
> recommendation this become a target hook with the default off so that 
> ports can be appropriately audited.

Ok. What I seem to have missed is that "profile_before_prologue" only refers to the profiling code
emitted by the FUNCTION_PROFILER macro.  Profiling code emitted by PROFILE_HOOK comes after the
prologue even if "profile_before_prologue" is true.

-Andreas-

> 
> Jeff
> 


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