libavcodec/ppc/gmc_altivec.c

   1 /*
   2  * GMC (Global Motion Compensation)
   3  * AltiVec-enabled
   4  * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "../dsputil.h"
  22
  23 #include "gcc_fixes.h"
  24
  25 #include "dsputil_altivec.h"
  26
  27 /*
  28   altivec-enhanced gmc1. ATM this code assume stride is a multiple of 8,
  29   to preserve proper dst alignement.
  30 */
  31 #define GMC1_PERF_COND (h==8)
  32 void gmc1_altivec(uint8_t *dst /* align 8 */, uint8_t *src /* align1 */, int stride, int h, int x16, int y16, int rounder)
  33 {
  34 POWERPC_PERF_DECLARE(altivec_gmc1_num, GMC1_PERF_COND);
  35 #ifdef ALTIVEC_USE_REFERENCE_C_CODE
  36     const int A=(16-x16)*(16-y16);
  37     const int B=(   x16)*(16-y16);
  38     const int C=(16-x16)*(   y16);
  39     const int D=(   x16)*(   y16);
  40     int i;
  41
  42 POWERPC_PERF_START_COUNT(altivec_gmc1_num, GMC1_PERF_COND);
  43
  44     for(i=0; i<h; i++)
  45     {
  46         dst[0]= (A*src[0] + B*src[1] + C*src[stride+0] + D*src[stride+1] + rounder)>>8;
  47         dst[1]= (A*src[1] + B*src[2] + C*src[stride+1] + D*src[stride+2] + rounder)>>8;
  48         dst[2]= (A*src[2] + B*src[3] + C*src[stride+2] + D*src[stride+3] + rounder)>>8;
  49         dst[3]= (A*src[3] + B*src[4] + C*src[stride+3] + D*src[stride+4] + rounder)>>8;
  50         dst[4]= (A*src[4] + B*src[5] + C*src[stride+4] + D*src[stride+5] + rounder)>>8;
  51         dst[5]= (A*src[5] + B*src[6] + C*src[stride+5] + D*src[stride+6] + rounder)>>8;
  52         dst[6]= (A*src[6] + B*src[7] + C*src[stride+6] + D*src[stride+7] + rounder)>>8;
  53         dst[7]= (A*src[7] + B*src[8] + C*src[stride+7] + D*src[stride+8] + rounder)>>8;
  54         dst+= stride;
  55         src+= stride;
  56     }
  57
  58 POWERPC_PERF_STOP_COUNT(altivec_gmc1_num, GMC1_PERF_COND);
  59
  60 #else /* ALTIVEC_USE_REFERENCE_C_CODE */
  61     const unsigned short __attribute__ ((aligned(16))) rounder_a[8] =
  62       {rounder, rounder, rounder, rounder,
  63        rounder, rounder, rounder, rounder};
  64     const unsigned short __attribute__ ((aligned(16))) ABCD[8] =
  65       {
  66         (16-x16)*(16-y16), /* A */
  67         (   x16)*(16-y16), /* B */
  68         (16-x16)*(   y16), /* C */
  69         (   x16)*(   y16), /* D */
  70         0, 0, 0, 0         /* padding */
  71       };
  72     register const_vector unsigned char vczero = (const_vector unsigned char)vec_splat_u8(0);
  73     register const_vector unsigned short vcsr8 = (const_vector unsigned short)vec_splat_u16(8);
  74     register vector unsigned char dstv, dstv2, src_0, src_1, srcvA, srcvB, srcvC, srcvD;
  75     register vector unsigned short Av, Bv, Cv, Dv, rounderV, tempA, tempB, tempC, tempD;
  76     int i;
  77     unsigned long dst_odd = (unsigned long)dst & 0x0000000F;
  78     unsigned long src_really_odd = (unsigned long)src & 0x0000000F;
  79
  80
  81 POWERPC_PERF_START_COUNT(altivec_gmc1_num, GMC1_PERF_COND);
  82
  83     tempA = vec_ld(0, (unsigned short*)ABCD);
  84     Av = vec_splat(tempA, 0);
  85     Bv = vec_splat(tempA, 1);
  86     Cv = vec_splat(tempA, 2);
  87     Dv = vec_splat(tempA, 3);
  88
  89     rounderV = vec_ld(0, (unsigned short*)rounder_a);
  90
  91     // we'll be able to pick-up our 9 char elements
  92     // at src from those 32 bytes
  93     // we load the first batch here, as inside the loop
  94     // we can re-use 'src+stride' from one iteration
  95     // as the 'src' of the next.
  96     src_0 = vec_ld(0, src);
  97     src_1 = vec_ld(16, src);
  98     srcvA = vec_perm(src_0, src_1, vec_lvsl(0, src));
  99
 100     if (src_really_odd != 0x0000000F)
 101     { // if src & 0xF == 0xF, then (src+1) is properly aligned on the second vector.
 102       srcvB = vec_perm(src_0, src_1, vec_lvsl(1, src));
 103     }
 104     else
 105     {
 106       srcvB = src_1;
 107     }
 108     srcvA = vec_mergeh(vczero, srcvA);
 109     srcvB = vec_mergeh(vczero, srcvB);
 110
 111     for(i=0; i<h; i++)
 112     {
 113       dst_odd = (unsigned long)dst & 0x0000000F;
 114       src_really_odd = (((unsigned long)src) + stride) & 0x0000000F;
 115
 116       dstv = vec_ld(0, dst);
 117
 118       // we we'll be able to pick-up our 9 char elements
 119       // at src + stride from those 32 bytes
 120       // then reuse the resulting 2 vectors srvcC and srcvD
 121       // as the next srcvA and srcvB
 122       src_0 = vec_ld(stride + 0, src);
 123       src_1 = vec_ld(stride + 16, src);
 124       srcvC = vec_perm(src_0, src_1, vec_lvsl(stride + 0, src));
 125
 126       if (src_really_odd != 0x0000000F)
 127       { // if src & 0xF == 0xF, then (src+1) is properly aligned on the second vector.
 128         srcvD = vec_perm(src_0, src_1, vec_lvsl(stride + 1, src));
 129       }
 130       else
 131       {
 132         srcvD = src_1;
 133       }
 134
 135       srcvC = vec_mergeh(vczero, srcvC);
 136       srcvD = vec_mergeh(vczero, srcvD);
 137
 138
 139       // OK, now we (finally) do the math :-)
 140       // those four instructions replaces 32 int muls & 32 int adds.
 141       // isn't AltiVec nice ?
 142       tempA = vec_mladd((vector unsigned short)srcvA, Av, rounderV);
 143       tempB = vec_mladd((vector unsigned short)srcvB, Bv, tempA);
 144       tempC = vec_mladd((vector unsigned short)srcvC, Cv, tempB);
 145       tempD = vec_mladd((vector unsigned short)srcvD, Dv, tempC);
 146
 147       srcvA = srcvC;
 148       srcvB = srcvD;
 149
 150       tempD = vec_sr(tempD, vcsr8);
 151
 152       dstv2 = vec_pack(tempD, (vector unsigned short)vczero);
 153
 154       if (dst_odd)
 155       {
 156         dstv2 = vec_perm(dstv, dstv2, vcprm(0,1,s0,s1));
 157       }
 158       else
 159       {
 160         dstv2 = vec_perm(dstv, dstv2, vcprm(s0,s1,2,3));
 161       }
 162
 163       vec_st(dstv2, 0, dst);
 164
 165       dst += stride;
 166       src += stride;
 167     }
 168
 169 POWERPC_PERF_STOP_COUNT(altivec_gmc1_num, GMC1_PERF_COND);
 170
 171 #endif /* ALTIVEC_USE_REFERENCE_C_CODE */
 172 }