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Re: [PATCH i386]: Enable push/pop in pro/epilogue for modern CPUs
On Thu, Dec 20, 2012 at 4:13 AM, Melik-adamyan, Areg
<areg.melik-adamyan@intel.com> wrote:
> We checked, no significant gains or losses.
>
> -----Original Message-----
> From: H.J. Lu [mailto:hjl.tools@gmail.com]
> Sent: Friday, December 14, 2012 1:03 AM
> To: Jan Hubicka
> Cc: Jakub Jelinek; Xinliang David Li; GCC Patches; Teresa Johnson; Melik-adamyan, Areg
> Subject: Re: [PATCH i386]: Enable push/pop in pro/epilogue for modern CPUs
>
> On Thu, Dec 13, 2012 at 12:40 PM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> > Here we speak about memcpy/memset only. I never got around to
>>> > modernize strlen and friends, unfortunately...
>>> >
>>> > memcmp and friends are different beats. They realy need some TLC...
>>>
>>> memcpy and memset in glibc are also extremely fast.
>>
>> The default strategy now is to inline only when the block is known to
>> be small (either constant or via profile feedback, we do not really
>> use the info on upper bound of size of the copied object that would be
>> useful but not readilly available at expansion time).
>>
>> You can try the test_stringop script I attached and send me the
>> results. For
>
> Areg, can you give it a try? Thanks.
>
Hi Areg,
Did you mean inlined memcpy/memset are as fast as
the ones in libc.so on both ia32 and Intel64?
Please keep in mind that memcpy/memset in libc.a
may not be optimized. You must not use -static for
linking.
--
H.J.