[FFmpeg-devel] [PATCH]Simplify mlp_filter_channel_x86()
michaelni at gmx.at
Thu Feb 19 20:09:57 CET 2015
On Thu, Feb 19, 2015 at 05:13:19PM +0000, Carl Eugen Hoyos wrote:
> Hendrik Leppkes <h.leppkes <at> gmail.com> writes:
> > > Attached patch by Francisco Blas Izquierdo Riera
> > > fixes a compilation error in mlpdsp_init.c with
> > > -fstack-check and some gcc compilers (I reproduced
> > > the issue with gcc 4.7.3) by simplifying the code.
> > > I ran some benchmarks with a very large thd file,
> > > 'time' confirms the results of '-benchmark'.
> > Please benchmark ASM changes using STAR/STOP_TIMER
> > macros.
> It's 5400 without vs 5500 decicyles with the patch
> I (still) find it very hard to understand that
> testing a few bytes of input data has more
> meaning than running decoding several GBs
> several times.
> > Looking at the code, the change introduces one
> > extra instruction in x64, and is identical in x86,
> > so I don't really see how it can be faster?
> I am not claiming it is faster.
> Just that a slowdown is not reproducible.
something like this can possibly be used to fix build of the file
until someone rewrites it to yasm
diff --git a/libavcodec/x86/Makefile b/libavcodec/x86/Makefile
index 7c4f4cd..b96b2ea 100644
@@ -164,3 +164,5 @@ YASM-OBJS-$(CONFIG_VP9_DECODER) += x86/vp9intrapred.o \
YASM-OBJS-$(CONFIG_WEBP_DECODER) += x86/vp8dsp.o
+$(SUBDIR)x86/mlpdsp_init.o: CFLAGS := $(subst -fstack-check, -fno-stack-check, $(CFLAGS))
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
There will always be a question for which you do not know the correct answer.
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