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

[Ramiro Polla]

Hi Gyan,

On Sat, Mar 29, 2025 at 6:11 AM Gyan Doshi <ffmpeg at gyani.pro> wrote:
> 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:
> >>>> 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.

Did you not try to use GNU make's flie function?

https://www.gnu.org/software/make/manual/html_node/File-Function.html

Ramiro