[Mesa-dev] [PATCH V3] mesa: add SSE optimisation for glDrawElements

[Timothy Arceri]

On Sun, 2014-10-26 at 11:16 +0000, Bruno Jimenez wrote:
> On Sun, 2014-10-26 at 10:47 +1100, Timothy Arceri wrote:
> > Makes use of SSE to speed up compute of min and max elements
> > 
> > Callgrind cpu usage results from pts benchmarks:
> > 
> > Openarena 0.8.8: 3.67% -> 1.03%
> > UrbanTerror: 2.36% -> 0.81%
> > 
> > Signed-off-by: Timothy Arceri <t_arceri at yahoo.com.au>
> > ---
> >  src/mesa/Android.libmesa_dricore.mk |  3 +-
> >  src/mesa/Makefile.am                |  3 +-
> >  src/mesa/main/sse_minmax.c          | 92 +++++++++++++++++++++++++++++++++++++
> >  src/mesa/main/sse_minmax.h          | 30 ++++++++++++
> >  src/mesa/vbo/vbo_exec_array.c       | 14 ++++--
> >  5 files changed, 137 insertions(+), 5 deletions(-)
> >  create mode 100644 src/mesa/main/sse_minmax.c
> >  create mode 100644 src/mesa/main/sse_minmax.h
> > 
> > Thanks again to everyone for the feedback.
> > 
> > V3:
> > 
> > - Removed sse_minmax.c from Makefile.sources
> > - handle the first few values without SSE until the pointer is aligned
> >  and use _mm_load_si128 rather than _mm_loadu_si128
> > - guard the call to the SSE code better at build time
> > 
> > diff --git a/src/mesa/Android.libmesa_dricore.mk b/src/mesa/Android.libmesa_dricore.mk
> > index 1e6d948..52d626f 100644
> > --- a/src/mesa/Android.libmesa_dricore.mk
> > +++ b/src/mesa/Android.libmesa_dricore.mk
> > @@ -51,7 +51,8 @@ endif # MESA_ENABLE_ASM
> >  
> >  ifeq ($(ARCH_X86_HAVE_SSE4_1),true)
> >  LOCAL_SRC_FILES += \
> > -	$(SRCDIR)main/streaming-load-memcpy.c
> > +	$(SRCDIR)main/streaming-load-memcpy.c \
> > +	$(SRCDIR)main/sse_minmax.c
> >  LOCAL_CFLAGS := -msse4.1
> >  endif
> >  
> > diff --git a/src/mesa/Makefile.am b/src/mesa/Makefile.am
> > index e71bccb..932db4f 100644
> > --- a/src/mesa/Makefile.am
> > +++ b/src/mesa/Makefile.am
> > @@ -151,7 +151,8 @@ libmesagallium_la_LIBADD = \
> >  	$(ARCH_LIBS)
> >  
> >  libmesa_sse41_la_SOURCES = \
> > -	main/streaming-load-memcpy.c
> > +	main/streaming-load-memcpy.c \
> > +	main/sse_minmax.c
> >  libmesa_sse41_la_CFLAGS = $(AM_CFLAGS) -msse4.1
> >  
> >  pkgconfigdir = $(libdir)/pkgconfig
> > diff --git a/src/mesa/main/sse_minmax.c b/src/mesa/main/sse_minmax.c
> > new file mode 100644
> > index 0000000..8f05982
> > --- /dev/null
> > +++ b/src/mesa/main/sse_minmax.c
> > @@ -0,0 +1,92 @@
> > +/*
> > + * Copyright © 2014 Timothy Arceri
> > + *
> > + * Permission is hereby granted, free of charge, to any person obtaining a
> > + * copy of this software and associated documentation files (the "Software"),
> > + * to deal in the Software without restriction, including without limitation
> > + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> > + * and/or sell copies of the Software, and to permit persons to whom the
> > + * Software is furnished to do so, subject to the following conditions:
> > + *
> > + * The above copyright notice and this permission notice (including the next
> > + * paragraph) shall be included in all copies or substantial portions of the
> > + * Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> > + * IN THE SOFTWARE.
> > + *
> > + * Author:
> > + *    Timothy Arceri <t_arceri at yahoo.com.au>
> > + *
> > + */
> > +
> > +#ifdef __SSE4_1__
> > +#include "main/sse_minmax.h"
> > +#include <smmintrin.h>
> > +#include <stdint.h>
> > +
> > +void
> > +_mesa_uint_array_min_max(const unsigned *ui_indices, unsigned *min_index,
> > +                         unsigned *max_index, const unsigned count)
> > +{
> > +   unsigned max_ui = 0;
> > +   unsigned min_ui = ~0U;
> > +   unsigned i = 0;
> > +
> > +   /* handle the first few values without SSE until the pointer is aligned */
> > +   while (((uintptr_t)ui_indices & 15) && (i < count)) {
> > +      if (ui_indices[i] > max_ui)
> > +         max_ui = ui_indices[i];
> > +      if (ui_indices[i] < min_ui)
> > +         min_ui = ui_indices[i];
> > +
> > +      i++;
> > +      ui_indices++;
> > +   }
> 
> Hi,
> 
> I think that this is wrong. If you advance the pointer and the index you
> will be jumping over some values. Maybe what you wanted was something
> like:
> 
> if (*ui_indices > max_ui)
>     max_ui = *ui_indices;
> if (*ui_indices < min_ui)
>     min_ui = *ui_indices;
> 

Yeah thanks. I think I've messed things up big time by advancing the
pointer, as well as what you have pointed out I think I need to also
recalculate the count in the code that follows.

It was working in my testing as the values so far have just happened to
be aligned.

> - Bruno