PowerPC : GCC2 optimises better than GCC4???

[Andrew Haley]

On 01/06/2010 09:59 AM, Mark Colby wrote:
>>>> Yabbut, how come RTL cse can handle it in x86_64, but PPC not?
>>>
>>> Probably because the RTL on x86_64 uses and's and ior's, but PPC uses
>>> set's of zero_extract's (insvsi).
>>
>> Aha!  Yes, that'll probably be it.  It should be easy to fix cse to
>> recognize those too.

> I'm not familiar with the gcc source yet, but just in case I get the
> time to look at this, could anyone give me a file/line ref to dive
> into and examine?

Would you believe cse.c?  :-)

I can't find the line without investigating further.

Andrew.

P.S.  This is a nontrivial task if you don't know gcc, but might be a
good place for a beginner to start.  OTOH, might be hard: no way to
know without digging.