[XviD-devel] Proposed patch
pascal.massimino@free.fr
pascal.massimino at free.fr
Mon Nov 5 21:53:28 CET 2007
Hi everybody,
Quoting "carlo.bramix" <carlo.bramix at libero.it>:
> Hello,
> I must say that I didn't a speed test on the saturation of the quantizer with
> LUT.
> Actually, it looked nicer since previous code had to do an addition, two
> comparisons and two conditional jumps on a plain x86 (best case), while this
> one do everything, addition & clipping, with a single mov opcode.
> It could be better an "hybrid" fix with an #ifdef on DQUANT_SAT macro
> definition and preserve current solution too:
I must concur that a systematic table-access for 0.00001% of potentially
problematic cases sounds like overkill to me, as opposed to a simple
well-predicted test. What about using something like:
if (31U > (uint32)(quant-1)) {}
else { .. do something rare ... }
instead?
The rest looks very ok to me. Someone, care to commit?
skal
>
> #if 1 // to decide how to do so...
> static int __inline DQUANT_SAT(int quant)
> {
> if (quant > 31)
> quant = 31;
> else
> if (quant < 1)
> quant = 1;
> return quant;
> }
> #else
> static const int32_t dquant_table[4] = {
> -1, -2, 1, 2
> };
> #define DQUANT_SAT(_quant) dquant_saturate[(_quant) + 1]
> static const unsigned char dquant_saturate[] = {
> 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
> 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
> 23, 24, 25, 26, 27, 28, 29, 30, 31, 31, 31,
> };
> #endif
>
> because I admit that it also depends on the hardware platform: ARM and
> PowerPC versions will work better with previous code instead, otherwise they
> need to load address of dquant_saturate[] vector too.
> Or, more easily, you can just throw that idea of clipping...
> Even if there could be an hypothetical benefit, I don't think it will change
> the life of the users!
>
> Sincerely,
>
> Carlo Bramini.
>
> ---------- Initial Header -----------
>
> From : xvid-devel-bounces at xvid.org
> To : xvid-devel at xvid.org
> Cc :
> Date : Tue, 06 Nov 2007 02:31:57 +1030
> Subject : Re: [XviD-devel] Proposed patch
>
> > Hi Carlo
> >
> > Is the quantizer LUT really any good? Considering that the branches are
> > 100% predictable, I'd guess extra memory access is actually slowing it
> > down, as well as wasting memory. Unless you can show otherwise.
> >
> > The rest looks very good though.
> >
> > Radek
> >
> > carlo.bramix wrote:
> > > Hello,
> > > I would like to suggest the following patch.
> > > It doesn't apply "dangerous" changes, it should just simplify/improve
> some bits of code.
> > >
> > > Sincerely,
> > >
> > > Carlo Bramini
> > >
> > >
> > >
> > > Index: src/decoder.c
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/decoder.c,v
> > > retrieving revision 1.80
> > > diff -u -r1.80 decoder.c
> > > --- src/decoder.c 16 Apr 2007 19:01:28 -0000 1.80
> > > +++ src/decoder.c 5 Nov 2007 12:44:48 -0000
> > > @@ -234,6 +234,14 @@
> > > -1, -2, 1, 2
> > > };
> > >
> > > +#define DQUANT_SAT(_quant) dquant_saturate[(_quant) + 1]
> > > +
> > > +static const unsigned char dquant_saturate[] = {
> > > + 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
> > > + 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
> > > + 23, 24, 25, 26, 27, 28, 29, 30, 31, 31, 31,
> > > +};
> > > +
> > > /* decode an intra macroblock */
> > > static void
> > > decoder_mbintra(DECODER * dec,
> > > @@ -765,11 +773,7 @@
> > >
> > > if (mb->mode == MODE_INTRA_Q) {
> > > quant += dquant_table[BitstreamGetBits(bs, 2)];
> > > - if (quant > 31) {
> > > - quant = 31;
> > > - } else if (quant < 1) {
> > > - quant = 1;
> > > - }
> > > + quant = DQUANT_SAT(quant);
> > > }
> > > mb->quant = quant;
> > > mb->mvs[0].x = mb->mvs[0].y =
> > > @@ -1009,12 +1013,7 @@
> > > if (mb->mode == MODE_INTER_Q || mb->mode == MODE_INTRA_Q) {
> > > int dquant = dquant_table[BitstreamGetBits(bs, 2)];
> > > DPRINTF(XVID_DEBUG_MB, "dquant %i\n", dquant);
> > > - quant += dquant;
> > > - if (quant > 31) {
> > > - quant = 31;
> > > - } else if (quant < 1) {
> > > - quant = 1;
> > > - }
> > > + quant = DQUANT_SAT(quant+dquant);
> > > DPRINTF(XVID_DEBUG_MB, "quant %i\n", quant);
> > > }
> > > mb->quant = quant;
> > > @@ -1420,11 +1419,7 @@
> > > mb->cbp = 0;
> > >
> > > if (mb->mode && mb->cbp) {
> > > - quant += get_dbquant(bs);
> > > - if (quant > 31)
> > > - quant = 31;
> > > - else if (quant < 1)
> > > - quant = 1;
> > > + quant = DQUANT_SAT(quant + get_dbquant(bs));
> > > }
> > > mb->quant = quant;
> > >
> > > Index: src/image/x86_asm/colorspace_mmx.inc
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/image/x86_asm/colorspace_mmx.inc,v
> > > retrieving revision 1.4
> > > diff -u -r1.4 colorspace_mmx.inc
> > > --- src/image/x86_asm/colorspace_mmx.inc 29 Aug 2004 10:02:38 -0000 1.4
> > > +++ src/image/x86_asm/colorspace_mmx.inc 5 Nov 2007 12:44:49 -0000
> > > @@ -106,8 +106,7 @@
> > > sub ebx, edx
> > > mov [x_dif], ebx ; x_dif = -BYTES*fixed_width - x_stride
> > >
> > > - mov eax, ebp
> > > - sub eax, 1
> > > + lea eax, [ebp-1]
> > > push edx
> > > mul edx
> > > pop edx
> > > Index: src/image/x86_asm/colorspace_yuv_mmx.asm
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/image/x86_asm/colorspace_yuv_mmx.asm,v
> > > retrieving revision 1.6
> > > diff -u -r1.6 colorspace_yuv_mmx.asm
> > > --- src/image/x86_asm/colorspace_yuv_mmx.asm 30 Oct 2006 10:52:00
> -0000 1.6
> > > +++ src/image/x86_asm/colorspace_yuv_mmx.asm 5 Nov 2007 12:44:51 -0000
> > > @@ -47,6 +47,14 @@
> > > ; Helper macros
> > >
> ;=============================================================================
> > >
> > > +%macro _MOVQ 3
> > > +%if %1 == 1
> > > + movntq %2, %3 ; xmm
> > > +%else
> > > + movq %2, %3 ; plain mmx
> > > +%endif
> > > +%endmacro
> > > +
> > >
>
;------------------------------------------------------------------------------
> > > ; PLANE_COPY ( DST, DST_STRIDE, SRC, SRC_STRIDE, WIDTH, HEIGHT, OPT )
> > > ; DST dst buffer
> > > @@ -100,25 +108,14 @@
> > > movq mm7, [esi + 48]
> > > movq mm0, [esi + 56]
> > >
> > > -%if OPT == 0 ; plain mmx
> > > - movq [edi ], mm1 ; write to y_out
> > > - movq [edi + 8], mm2
> > > - movq [edi + 16], mm3
> > > - movq [edi + 24], mm4
> > > - movq [edi + 32], mm5
> > > - movq [edi + 40], mm6
> > > - movq [edi + 48], mm7
> > > - movq [edi + 56], mm0
> > > -%else
> > > - movntq [edi ], mm1 ; write to y_out
> > > - movntq [edi + 8], mm2
> > > - movntq [edi + 16], mm3
> > > - movntq [edi + 24], mm4
> > > - movntq [edi + 32], mm5
> > > - movntq [edi + 40], mm6
> > > - movntq [edi + 48], mm7
> > > - movntq [edi + 56], mm0
> > > -%endif
> > > + _MOVQ OPT, [edi ], mm1 ; write to y_out
> > > + _MOVQ OPT, [edi + 8], mm2
> > > + _MOVQ OPT, [edi + 16], mm3
> > > + _MOVQ OPT, [edi + 24], mm4
> > > + _MOVQ OPT, [edi + 32], mm5
> > > + _MOVQ OPT, [edi + 40], mm6
> > > + _MOVQ OPT, [edi + 48], mm7
> > > + _MOVQ OPT, [edi + 56], mm0
> > >
> > > add esi, 64
> > > add edi, 64
> > > @@ -133,13 +130,9 @@
> > > %%loop16_pc:
> > > movq mm1, [esi]
> > > movq mm2, [esi + 8]
> > > -%if OPT == 0 ; plain mmx
> > > - movq [edi], mm1
> > > - movq [edi + 8], mm2
> > > -%else
> > > - movntq [edi], mm1
> > > - movntq [edi + 8], mm2
> > > -%endif
> > > + _MOVQ OPT, [edi], mm1
> > > + _MOVQ OPT, [edi + 8], mm2
> > >
> > > add esi, 16
> > > add edi, 16
> > > @@ -195,26 +188,14 @@
> > > jz %%loop16_start_pf
> > >
> > > %%loop64_pf:
> > > -
> > > -%if OPT == 0 ; plain mmx
> > > - movq [edi ], mm0 ; write to y_out
> > > - movq [edi + 8], mm0
> > > - movq [edi + 16], mm0
> > > - movq [edi + 24], mm0
> > > - movq [edi + 32], mm0
> > > - movq [edi + 40], mm0
> > > - movq [edi + 48], mm0
> > > - movq [edi + 56], mm0
> > > -%else
> > > - movntq [edi ], mm0 ; write to y_out
> > > - movntq [edi + 8], mm0
> > > - movntq [edi + 16], mm0
> > > - movntq [edi + 24], mm0
> > > - movntq [edi + 32], mm0
> > > - movntq [edi + 40], mm0
> > > - movntq [edi + 48], mm0
> > > - movntq [edi + 56], mm0
> > > -%endif
> > > + _MOVQ OPT, [edi ], mm0 ; write to y_out
> > > + _MOVQ OPT, [edi + 8], mm0
> > > + _MOVQ OPT, [edi + 16], mm0
> > > + _MOVQ OPT, [edi + 24], mm0
> > > + _MOVQ OPT, [edi + 32], mm0
> > > + _MOVQ OPT, [edi + 40], mm0
> > > + _MOVQ OPT, [edi + 48], mm0
> > > + _MOVQ OPT, [edi + 56], mm0
> > >
> > > add edi, 64
> > > loop %%loop64_pf
> > > @@ -225,13 +206,8 @@
> > > jz %%loop1_start_pf
> > >
> > > %%loop16_pf:
> > > -%if OPT == 0 ; plain mmx
> > > - movq [edi ], mm0
> > > - movq [edi + 8], mm0
> > > -%else
> > > - movntq [edi ], mm0
> > > - movntq [edi + 8], mm0
> > > -%endif
> > > + _MOVQ OPT, [edi ], mm0
> > > + _MOVQ OPT, [edi + 8], mm0
> > >
> > > add edi, 16
> > > loop %%loop16_pf
> > > Index: src/image/x86_asm/interpolate8x8_mmx.asm
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/image/x86_asm/interpolate8x8_mmx.asm,v
> > > retrieving revision 1.18
> > > diff -u -r1.18 interpolate8x8_mmx.asm
> > > --- src/image/x86_asm/interpolate8x8_mmx.asm 13 Sep 2005 12:12:15
> -0000 1.18
> > > +++ src/image/x86_asm/interpolate8x8_mmx.asm 5 Nov 2007 12:44:53 -0000
> > > @@ -574,7 +574,6 @@
> > >
> > > mov eax, [esp + 4 + 24] ; height -> eax
> > > sub eax, 8
> > > - test eax, eax
> > >
> > > mov ecx, [esp + 4 + 4] ; dst -> edi
> > > mov eax, [esp + 4 + 8] ; src1 -> esi
> > > @@ -604,7 +603,6 @@
> > > .rounding1
> > > mov eax, [esp + 4 + 24] ; height -> eax
> > > sub eax, 8
> > > - test eax, eax
> > >
> > > mov ecx, [esp + 4 + 4] ; dst -> edi
> > > mov eax, [esp + 4 + 8] ; src1 -> esi
> > > @@ -1024,9 +1022,7 @@
> > > mov eax, [esp + 4 + 8] ; src -> esi
> > > mov edx, [esp + 4 + 12] ; stride -> edx
> > >
> > > - mov ebx, edx
> > > - shl ebx, 1
> > > - add ebx, edx
> > > + lea ebx, [edx+edx*2]
> > >
> > > pxor mm7, mm7
> > >
> > > Index: src/image/x86_asm/postprocessing_mmx.asm
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/image/x86_asm/postprocessing_mmx.asm,v
> > > retrieving revision 1.4
> > > diff -u -r1.4 postprocessing_mmx.asm
> > > --- src/image/x86_asm/postprocessing_mmx.asm 29 Aug 2004 10:02:38
> -0000 1.4
> > > +++ src/image/x86_asm/postprocessing_mmx.asm 5 Nov 2007 12:44:53 -0000
> > > @@ -115,7 +115,7 @@
> > > jl .xloop
> > >
> > > add edx, ecx ; dst += stride
> > > - sub edi, 1
> > > + dec edi
> > > jg .yloop
> > >
> > > pop edi
> > > Index: src/image/x86_asm/postprocessing_sse2.asm
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/image/x86_asm/postprocessing_sse2.asm,v
> > > retrieving revision 1.5
> > > diff -u -r1.5 postprocessing_sse2.asm
> > > --- src/image/x86_asm/postprocessing_sse2.asm 29 Aug 2004 10:02:38
> -0000 1.5
> > > +++ src/image/x86_asm/postprocessing_sse2.asm 5 Nov 2007 12:44:55 -0000
> > > @@ -130,7 +130,7 @@
> > > jl .xloop
> > >
> > > add edx, ecx ; dst += stride
> > > - sub edi, 1
> > > + dec edi
> > > jg .yloop
> > >
> > > add esp, 32
> > > Index: src/image/x86_asm/reduced_mmx.asm
> > > ===================================================================
> > > RCS file: /xvid/xvidcore/src/image/x86_asm/reduced_mmx.asm,v
> > > retrieving revision 1.6
> > > diff -u -r1.6 reduced_mmx.asm
> > > --- src/image/x86_asm/reduced_mmx.asm 29 Aug 2004 10:02:38 -0000 1.6
> > > +++ src/image/x86_asm/reduced_mmx.asm 5 Nov 2007 12:44:57 -0000
> > > @@ -758,7 +758,7 @@
> > > packuswb mm1, mm7
> > > movd [esi+eax*4], mm0
> > > movd [edi+eax*4], mm1
> > > - add eax,1
> > > + inc eax
> > > jl .Loop
> > >
> > > pop edi
> > >
> > > _______________________________________________
> > > XviD-devel mailing list
> > > XviD-devel at xvid.org
> > > http://list.xvid.org/mailman/listinfo/xvid-devel
> > >
> > >
> > _______________________________________________
> > XviD-devel mailing list
> > XviD-devel at xvid.org
> > http://list.xvid.org/mailman/listinfo/xvid-devel
> >
> _______________________________________________
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