[FFmpeg-devel] [PATCH 1/2] ffbuild: compose linker response files in a loop

[Gyan Doshi]

On 2025-03-27 10:03 am, Gyan Doshi wrote:
>
>
> On 2025-03-26 11:37 pm, Andreas Rheinhardt wrote:
>> Gyan Doshi:
>>>
>>> On 2025-03-25 05:11 pm, Ramiro Polla wrote:
>>>> Hi,
>>>>
>>>> On Sat, Mar 22, 2025 at 5:33 AM Gyan Doshi <ffmpeg at gyani.pro> wrote:
>>>>> On 2025-03-22 03:29 am, Martin Storsjö wrote:
>>>>>> On Fri, 21 Mar 2025, Gyan Doshi wrote:
>>>>>>> ffbuild/library.mak | 7 +++++--
>>>>>>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>>>>>>
>>>>>>> diff --git a/ffbuild/library.mak b/ffbuild/library.mak
>>>>>>> index 7e1871b74c..15302852ec 100644
>>>>>>> --- a/ffbuild/library.mak
>>>>>>> +++ b/ffbuild/library.mak
>>>>>>> @@ -36,7 +36,8 @@ endif
>>>>>>> $(SUBDIR)$(LIBNAME): $(OBJS) $(STLIBOBJS)
>>>>>>>       $(RM) $@
>>>>>>> ifeq ($(AR_OBJS),true)
>>>>>>> -    $(Q)echo $^ > $@.objs
>>>>>>> +    -$(RM) $@.objs
>>>>>>> +    $(Q)$(foreach ARG,$^,echo -n "$(ARG) " >> $@.objs;)
>>>>>> Does this instance even work, it looks broken, like it is missing
>>>>>> something?
>>>>> Tested both static and shared building. All working with no 
>>>>> noticeable
>>>>> speed difference although I didn't formally bench.
>>>> It's generally a good idea to check for and report the speed
>>>> differences. Even if just for the sake of curiosity.
>>> So, with this configure:
>>>
>>>    --disable-doc --disable-w32threads --enable-pthreads --disable-
>>> autodetect --cc="ccache gcc" --enable-static --enable-shared --extra-
>>> ldflags="-static" --enable-gpl --enable-version3
>>>
>>> I ran one priming run + 5 repeat runs of    `time make -j4`.
>>>
>>> Before, real ranged from 2m10.188s to 2m12.154s
>>> After, real ranged from 2m12.486s to 2m13.405s
>>>
>>> I also ran one priming run + 5 repeat runs of    `time make -j4
>>> libavcodec/libavcodec.a libavcodec/avcodec.dll`.
>>>
>>> Before, real ranged from 1m34.232s to 1m42.721s
>>> After, real ranged from 1m32.360s to 1m39.484s
>>>
>> I presume this command compiled the whole of FFmpeg/libavcodec, i.e. it
>> did not just link, didn't it?
>
> Its deps, are *.o in lavu, lswr, lavc, but after the priming run, all 
> the cc steps would be cache hits,
> so the bulk of the fresh executions are the linking steps.

Plan to push tomorrow.

Regards,
Gyan