libavcodec/ppc/mpegvideo_altivec.c

   1 /*
   2  * Copyright (c) 2002 Dieter Shirley
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21 #include "../dsputil.h"
  22 #include "../mpegvideo.h"
  23
  24 #include "gcc_fixes.h"
  25
  26 #include "dsputil_altivec.h"
  27
  28 // Swaps two variables (used for altivec registers)
  29 #define SWAP(a,b) \
  30 do { \
  31     __typeof__(a) swap_temp=a; \
  32     a=b; \
  33     b=swap_temp; \
  34 } while (0)
  35
  36 // transposes a matrix consisting of four vectors with four elements each
  37 #define TRANSPOSE4(a,b,c,d) \
  38 do { \
  39   __typeof__(a) _trans_ach = vec_mergeh(a, c); \
  40   __typeof__(a) _trans_acl = vec_mergel(a, c); \
  41   __typeof__(a) _trans_bdh = vec_mergeh(b, d); \
  42   __typeof__(a) _trans_bdl = vec_mergel(b, d); \
  43  \
  44   a = vec_mergeh(_trans_ach, _trans_bdh); \
  45   b = vec_mergel(_trans_ach, _trans_bdh); \
  46   c = vec_mergeh(_trans_acl, _trans_bdl); \
  47   d = vec_mergel(_trans_acl, _trans_bdl); \
  48 } while (0)
  49
  50 #define TRANSPOSE8(a,b,c,d,e,f,g,h) \
  51 do { \
  52     __typeof__(a)  _A1, _B1, _C1, _D1, _E1, _F1, _G1, _H1; \
  53     __typeof__(a)  _A2, _B2, _C2, _D2, _E2, _F2, _G2, _H2; \
  54  \
  55     _A1 = vec_mergeh (a, e); \
  56     _B1 = vec_mergel (a, e); \
  57     _C1 = vec_mergeh (b, f); \
  58     _D1 = vec_mergel (b, f); \
  59     _E1 = vec_mergeh (c, g); \
  60     _F1 = vec_mergel (c, g); \
  61     _G1 = vec_mergeh (d, h); \
  62     _H1 = vec_mergel (d, h); \
  63  \
  64     _A2 = vec_mergeh (_A1, _E1); \
  65     _B2 = vec_mergel (_A1, _E1); \
  66     _C2 = vec_mergeh (_B1, _F1); \
  67     _D2 = vec_mergel (_B1, _F1); \
  68     _E2 = vec_mergeh (_C1, _G1); \
  69     _F2 = vec_mergel (_C1, _G1); \
  70     _G2 = vec_mergeh (_D1, _H1); \
  71     _H2 = vec_mergel (_D1, _H1); \
  72  \
  73     a = vec_mergeh (_A2, _E2); \
  74     b = vec_mergel (_A2, _E2); \
  75     c = vec_mergeh (_B2, _F2); \
  76     d = vec_mergel (_B2, _F2); \
  77     e = vec_mergeh (_C2, _G2); \
  78     f = vec_mergel (_C2, _G2); \
  79     g = vec_mergeh (_D2, _H2); \
  80     h = vec_mergel (_D2, _H2); \
  81 } while (0)
  82
  83
  84 // Loads a four-byte value (int or float) from the target address
  85 // into every element in the target vector.  Only works if the
  86 // target address is four-byte aligned (which should be always).
  87 #define LOAD4(vec, address) \
  88 { \
  89     __typeof__(vec)* _load_addr = (__typeof__(vec)*)(address); \
  90     vector unsigned char _perm_vec = vec_lvsl(0,(address)); \
  91     vec = vec_ld(0, _load_addr); \
  92     vec = vec_perm(vec, vec, _perm_vec); \
  93     vec = vec_splat(vec, 0); \
  94 }
  95
  96
  97 #ifdef CONFIG_DARWIN
  98 #define FOUROF(a) (a)
  99 #else
 100 // slower, for dumb non-apple GCC
 101 #define FOUROF(a) {a,a,a,a}
 102 #endif
 103 int dct_quantize_altivec(MpegEncContext* s,
 104                         DCTELEM* data, int n,
 105                         int qscale, int* overflow)
 106 {
 107     int lastNonZero;
 108     vector float row0, row1, row2, row3, row4, row5, row6, row7;
 109     vector float alt0, alt1, alt2, alt3, alt4, alt5, alt6, alt7;
 110     const_vector float zero = (const_vector float)FOUROF(0.);
 111     // used after quantise step
 112     int oldBaseValue = 0;
 113
 114     // Load the data into the row/alt vectors
 115     {
 116         vector signed short data0, data1, data2, data3, data4, data5, data6, data7;
 117
 118         data0 = vec_ld(0, data);
 119         data1 = vec_ld(16, data);
 120         data2 = vec_ld(32, data);
 121         data3 = vec_ld(48, data);
 122         data4 = vec_ld(64, data);
 123         data5 = vec_ld(80, data);
 124         data6 = vec_ld(96, data);
 125         data7 = vec_ld(112, data);
 126
 127         // Transpose the data before we start
 128         TRANSPOSE8(data0, data1, data2, data3, data4, data5, data6, data7);
 129
 130         // load the data into floating point vectors.  We load
 131         // the high half of each row into the main row vectors
 132         // and the low half into the alt vectors.
 133         row0 = vec_ctf(vec_unpackh(data0), 0);
 134         alt0 = vec_ctf(vec_unpackl(data0), 0);
 135         row1 = vec_ctf(vec_unpackh(data1), 0);
 136         alt1 = vec_ctf(vec_unpackl(data1), 0);
 137         row2 = vec_ctf(vec_unpackh(data2), 0);
 138         alt2 = vec_ctf(vec_unpackl(data2), 0);
 139         row3 = vec_ctf(vec_unpackh(data3), 0);
 140         alt3 = vec_ctf(vec_unpackl(data3), 0);
 141         row4 = vec_ctf(vec_unpackh(data4), 0);
 142         alt4 = vec_ctf(vec_unpackl(data4), 0);
 143         row5 = vec_ctf(vec_unpackh(data5), 0);
 144         alt5 = vec_ctf(vec_unpackl(data5), 0);
 145         row6 = vec_ctf(vec_unpackh(data6), 0);
 146         alt6 = vec_ctf(vec_unpackl(data6), 0);
 147         row7 = vec_ctf(vec_unpackh(data7), 0);
 148         alt7 = vec_ctf(vec_unpackl(data7), 0);
 149     }
 150
 151     // The following block could exist as a separate an altivec dct
 152                 // function.  However, if we put it inline, the DCT data can remain
 153                 // in the vector local variables, as floats, which we'll use during the
 154                 // quantize step...
 155     {
 156         const vector float vec_0_298631336 = (vector float)FOUROF(0.298631336f);
 157         const vector float vec_0_390180644 = (vector float)FOUROF(-0.390180644f);
 158         const vector float vec_0_541196100 = (vector float)FOUROF(0.541196100f);
 159         const vector float vec_0_765366865 = (vector float)FOUROF(0.765366865f);
 160         const vector float vec_0_899976223 = (vector float)FOUROF(-0.899976223f);
 161         const vector float vec_1_175875602 = (vector float)FOUROF(1.175875602f);
 162         const vector float vec_1_501321110 = (vector float)FOUROF(1.501321110f);
 163         const vector float vec_1_847759065 = (vector float)FOUROF(-1.847759065f);
 164         const vector float vec_1_961570560 = (vector float)FOUROF(-1.961570560f);
 165         const vector float vec_2_053119869 = (vector float)FOUROF(2.053119869f);
 166         const vector float vec_2_562915447 = (vector float)FOUROF(-2.562915447f);
 167         const vector float vec_3_072711026 = (vector float)FOUROF(3.072711026f);
 168
 169
 170         int whichPass, whichHalf;
 171
 172         for(whichPass = 1; whichPass<=2; whichPass++)
 173         {
 174             for(whichHalf = 1; whichHalf<=2; whichHalf++)
 175             {
 176                 vector float tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
 177                 vector float tmp10, tmp11, tmp12, tmp13;
 178                 vector float z1, z2, z3, z4, z5;
 179
 180                 tmp0 = vec_add(row0, row7); // tmp0 = dataptr[0] + dataptr[7];
 181                 tmp7 = vec_sub(row0, row7); // tmp7 = dataptr[0] - dataptr[7];
 182                 tmp3 = vec_add(row3, row4); // tmp3 = dataptr[3] + dataptr[4];
 183                 tmp4 = vec_sub(row3, row4); // tmp4 = dataptr[3] - dataptr[4];
 184                 tmp1 = vec_add(row1, row6); // tmp1 = dataptr[1] + dataptr[6];
 185                 tmp6 = vec_sub(row1, row6); // tmp6 = dataptr[1] - dataptr[6];
 186                 tmp2 = vec_add(row2, row5); // tmp2 = dataptr[2] + dataptr[5];
 187                 tmp5 = vec_sub(row2, row5); // tmp5 = dataptr[2] - dataptr[5];
 188
 189                 tmp10 = vec_add(tmp0, tmp3); // tmp10 = tmp0 + tmp3;
 190                 tmp13 = vec_sub(tmp0, tmp3); // tmp13 = tmp0 - tmp3;
 191                 tmp11 = vec_add(tmp1, tmp2); // tmp11 = tmp1 + tmp2;
 192                 tmp12 = vec_sub(tmp1, tmp2); // tmp12 = tmp1 - tmp2;
 193
 194
 195                 // dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
 196                 row0 = vec_add(tmp10, tmp11);
 197
 198                 // dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
 199                 row4 = vec_sub(tmp10, tmp11);
 200
 201
 202                 // z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
 203                 z1 = vec_madd(vec_add(tmp12, tmp13), vec_0_541196100, (vector float)zero);
 204
 205                 // dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
 206                 //                 CONST_BITS-PASS1_BITS);
 207                 row2 = vec_madd(tmp13, vec_0_765366865, z1);
 208
 209                 // dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
 210                 //                 CONST_BITS-PASS1_BITS);
 211                 row6 = vec_madd(tmp12, vec_1_847759065, z1);
 212
 213                 z1 = vec_add(tmp4, tmp7); // z1 = tmp4 + tmp7;
 214                 z2 = vec_add(tmp5, tmp6); // z2 = tmp5 + tmp6;
 215                 z3 = vec_add(tmp4, tmp6); // z3 = tmp4 + tmp6;
 216                 z4 = vec_add(tmp5, tmp7); // z4 = tmp5 + tmp7;
 217
 218                 // z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
 219                 z5 = vec_madd(vec_add(z3, z4), vec_1_175875602, (vector float)zero);
 220
 221                 // z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
 222                 z3 = vec_madd(z3, vec_1_961570560, z5);
 223
 224                 // z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
 225                 z4 = vec_madd(z4, vec_0_390180644, z5);
 226
 227                 // The following adds are rolled into the multiplies above
 228                 // z3 = vec_add(z3, z5);  // z3 += z5;
 229                 // z4 = vec_add(z4, z5);  // z4 += z5;
 230
 231                 // z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
 232                 // Wow!  It's actually more effecient to roll this multiply
 233                 // into the adds below, even thought the multiply gets done twice!
 234                 // z2 = vec_madd(z2, vec_2_562915447, (vector float)zero);
 235
 236                 // z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
 237                 // Same with this one...
 238                 // z1 = vec_madd(z1, vec_0_899976223, (vector float)zero);
 239
 240                 // tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
 241                 // dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
 242                 row7 = vec_madd(tmp4, vec_0_298631336, vec_madd(z1, vec_0_899976223, z3));
 243
 244                 // tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
 245                 // dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
 246                 row5 = vec_madd(tmp5, vec_2_053119869, vec_madd(z2, vec_2_562915447, z4));
 247
 248                 // tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
 249                 // dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
 250                 row3 = vec_madd(tmp6, vec_3_072711026, vec_madd(z2, vec_2_562915447, z3));
 251
 252                 // tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
 253                 // dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
 254                 row1 = vec_madd(z1, vec_0_899976223, vec_madd(tmp7, vec_1_501321110, z4));
 255
 256                 // Swap the row values with the alts.  If this is the first half,
 257                 // this sets up the low values to be acted on in the second half.
 258                 // If this is the second half, it puts the high values back in
 259                 // the row values where they are expected to be when we're done.
 260                 SWAP(row0, alt0);
 261                 SWAP(row1, alt1);
 262                 SWAP(row2, alt2);
 263                 SWAP(row3, alt3);
 264                 SWAP(row4, alt4);
 265                 SWAP(row5, alt5);
 266                 SWAP(row6, alt6);
 267                 SWAP(row7, alt7);
 268             }
 269
 270             if (whichPass == 1)
 271             {
 272                 // transpose the data for the second pass
 273
 274                 // First, block transpose the upper right with lower left.
 275                 SWAP(row4, alt0);
 276                 SWAP(row5, alt1);
 277                 SWAP(row6, alt2);
 278                 SWAP(row7, alt3);
 279
 280                 // Now, transpose each block of four
 281                 TRANSPOSE4(row0, row1, row2, row3);
 282                 TRANSPOSE4(row4, row5, row6, row7);
 283                 TRANSPOSE4(alt0, alt1, alt2, alt3);
 284                 TRANSPOSE4(alt4, alt5, alt6, alt7);
 285             }
 286         }
 287     }
 288
 289     // perform the quantise step, using the floating point data
 290     // still in the row/alt registers
 291     {
 292         const int* biasAddr;
 293         const vector signed int* qmat;
 294         vector float bias, negBias;
 295
 296         if (s->mb_intra)
 297         {
 298             vector signed int baseVector;
 299
 300             // We must cache element 0 in the intra case
 301             // (it needs special handling).
 302             baseVector = vec_cts(vec_splat(row0, 0), 0);
 303             vec_ste(baseVector, 0, &oldBaseValue);
 304
 305             qmat = (vector signed int*)s->q_intra_matrix[qscale];
 306             biasAddr = &(s->intra_quant_bias);
 307         }
 308         else
 309         {
 310             qmat = (vector signed int*)s->q_inter_matrix[qscale];
 311             biasAddr = &(s->inter_quant_bias);
 312         }
 313
 314         // Load the bias vector (We add 0.5 to the bias so that we're
 315                                 // rounding when we convert to int, instead of flooring.)
 316         {
 317             vector signed int biasInt;
 318             const vector float negOneFloat = (vector float)FOUROF(-1.0f);
 319             LOAD4(biasInt, biasAddr);
 320             bias = vec_ctf(biasInt, QUANT_BIAS_SHIFT);
 321             negBias = vec_madd(bias, negOneFloat, zero);
 322         }
 323
 324         {
 325             vector float q0, q1, q2, q3, q4, q5, q6, q7;
 326
 327             q0 = vec_ctf(qmat[0], QMAT_SHIFT);
 328             q1 = vec_ctf(qmat[2], QMAT_SHIFT);
 329             q2 = vec_ctf(qmat[4], QMAT_SHIFT);
 330             q3 = vec_ctf(qmat[6], QMAT_SHIFT);
 331             q4 = vec_ctf(qmat[8], QMAT_SHIFT);
 332             q5 = vec_ctf(qmat[10], QMAT_SHIFT);
 333             q6 = vec_ctf(qmat[12], QMAT_SHIFT);
 334             q7 = vec_ctf(qmat[14], QMAT_SHIFT);
 335
 336             row0 = vec_sel(vec_madd(row0, q0, negBias), vec_madd(row0, q0, bias),
 337                     vec_cmpgt(row0, zero));
 338             row1 = vec_sel(vec_madd(row1, q1, negBias), vec_madd(row1, q1, bias),
 339                     vec_cmpgt(row1, zero));
 340             row2 = vec_sel(vec_madd(row2, q2, negBias), vec_madd(row2, q2, bias),
 341                     vec_cmpgt(row2, zero));
 342             row3 = vec_sel(vec_madd(row3, q3, negBias), vec_madd(row3, q3, bias),
 343                     vec_cmpgt(row3, zero));
 344             row4 = vec_sel(vec_madd(row4, q4, negBias), vec_madd(row4, q4, bias),
 345                     vec_cmpgt(row4, zero));
 346             row5 = vec_sel(vec_madd(row5, q5, negBias), vec_madd(row5, q5, bias),
 347                     vec_cmpgt(row5, zero));
 348             row6 = vec_sel(vec_madd(row6, q6, negBias), vec_madd(row6, q6, bias),
 349                     vec_cmpgt(row6, zero));
 350             row7 = vec_sel(vec_madd(row7, q7, negBias), vec_madd(row7, q7, bias),
 351                     vec_cmpgt(row7, zero));
 352
 353             q0 = vec_ctf(qmat[1], QMAT_SHIFT);
 354             q1 = vec_ctf(qmat[3], QMAT_SHIFT);
 355             q2 = vec_ctf(qmat[5], QMAT_SHIFT);
 356             q3 = vec_ctf(qmat[7], QMAT_SHIFT);
 357             q4 = vec_ctf(qmat[9], QMAT_SHIFT);
 358             q5 = vec_ctf(qmat[11], QMAT_SHIFT);
 359             q6 = vec_ctf(qmat[13], QMAT_SHIFT);
 360             q7 = vec_ctf(qmat[15], QMAT_SHIFT);
 361
 362             alt0 = vec_sel(vec_madd(alt0, q0, negBias), vec_madd(alt0, q0, bias),
 363                     vec_cmpgt(alt0, zero));
 364             alt1 = vec_sel(vec_madd(alt1, q1, negBias), vec_madd(alt1, q1, bias),
 365                     vec_cmpgt(alt1, zero));
 366             alt2 = vec_sel(vec_madd(alt2, q2, negBias), vec_madd(alt2, q2, bias),
 367                     vec_cmpgt(alt2, zero));
 368             alt3 = vec_sel(vec_madd(alt3, q3, negBias), vec_madd(alt3, q3, bias),
 369                     vec_cmpgt(alt3, zero));
 370             alt4 = vec_sel(vec_madd(alt4, q4, negBias), vec_madd(alt4, q4, bias),
 371                     vec_cmpgt(alt4, zero));
 372             alt5 = vec_sel(vec_madd(alt5, q5, negBias), vec_madd(alt5, q5, bias),
 373                     vec_cmpgt(alt5, zero));
 374             alt6 = vec_sel(vec_madd(alt6, q6, negBias), vec_madd(alt6, q6, bias),
 375                     vec_cmpgt(alt6, zero));
 376             alt7 = vec_sel(vec_madd(alt7, q7, negBias), vec_madd(alt7, q7, bias),
 377                     vec_cmpgt(alt7, zero));
 378         }
 379
 380
 381     }
 382
 383     // Store the data back into the original block
 384     {
 385         vector signed short data0, data1, data2, data3, data4, data5, data6, data7;
 386
 387         data0 = vec_pack(vec_cts(row0, 0), vec_cts(alt0, 0));
 388         data1 = vec_pack(vec_cts(row1, 0), vec_cts(alt1, 0));
 389         data2 = vec_pack(vec_cts(row2, 0), vec_cts(alt2, 0));
 390         data3 = vec_pack(vec_cts(row3, 0), vec_cts(alt3, 0));
 391         data4 = vec_pack(vec_cts(row4, 0), vec_cts(alt4, 0));
 392         data5 = vec_pack(vec_cts(row5, 0), vec_cts(alt5, 0));
 393         data6 = vec_pack(vec_cts(row6, 0), vec_cts(alt6, 0));
 394         data7 = vec_pack(vec_cts(row7, 0), vec_cts(alt7, 0));
 395
 396         {
 397             // Clamp for overflow
 398             vector signed int max_q_int, min_q_int;
 399             vector signed short max_q, min_q;
 400
 401             LOAD4(max_q_int, &(s->max_qcoeff));
 402             LOAD4(min_q_int, &(s->min_qcoeff));
 403
 404             max_q = vec_pack(max_q_int, max_q_int);
 405             min_q = vec_pack(min_q_int, min_q_int);
 406
 407             data0 = vec_max(vec_min(data0, max_q), min_q);
 408             data1 = vec_max(vec_min(data1, max_q), min_q);
 409             data2 = vec_max(vec_min(data2, max_q), min_q);
 410             data4 = vec_max(vec_min(data4, max_q), min_q);
 411             data5 = vec_max(vec_min(data5, max_q), min_q);
 412             data6 = vec_max(vec_min(data6, max_q), min_q);
 413             data7 = vec_max(vec_min(data7, max_q), min_q);
 414         }
 415
 416         {
 417         vector bool char zero_01, zero_23, zero_45, zero_67;
 418         vector signed char scanIndices_01, scanIndices_23, scanIndices_45, scanIndices_67;
 419         vector signed char negOne = vec_splat_s8(-1);
 420         vector signed char* scanPtr =
 421                 (vector signed char*)(s->intra_scantable.inverse);
 422         signed char lastNonZeroChar;
 423
 424         // Determine the largest non-zero index.
 425         zero_01 = vec_pack(vec_cmpeq(data0, (vector signed short)zero),
 426                 vec_cmpeq(data1, (vector signed short)zero));
 427         zero_23 = vec_pack(vec_cmpeq(data2, (vector signed short)zero),
 428                 vec_cmpeq(data3, (vector signed short)zero));
 429         zero_45 = vec_pack(vec_cmpeq(data4, (vector signed short)zero),
 430                 vec_cmpeq(data5, (vector signed short)zero));
 431         zero_67 = vec_pack(vec_cmpeq(data6, (vector signed short)zero),
 432                 vec_cmpeq(data7, (vector signed short)zero));
 433
 434         // 64 biggest values
 435         scanIndices_01 = vec_sel(scanPtr[0], negOne, zero_01);
 436         scanIndices_23 = vec_sel(scanPtr[1], negOne, zero_23);
 437         scanIndices_45 = vec_sel(scanPtr[2], negOne, zero_45);
 438         scanIndices_67 = vec_sel(scanPtr[3], negOne, zero_67);
 439
 440         // 32 largest values
 441         scanIndices_01 = vec_max(scanIndices_01, scanIndices_23);
 442         scanIndices_45 = vec_max(scanIndices_45, scanIndices_67);
 443
 444         // 16 largest values
 445         scanIndices_01 = vec_max(scanIndices_01, scanIndices_45);
 446
 447         // 8 largest values
 448         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
 449                 vec_mergel(scanIndices_01, negOne));
 450
 451         // 4 largest values
 452         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
 453                 vec_mergel(scanIndices_01, negOne));
 454
 455         // 2 largest values
 456         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
 457                 vec_mergel(scanIndices_01, negOne));
 458
 459         // largest value
 460         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
 461                 vec_mergel(scanIndices_01, negOne));
 462
 463         scanIndices_01 = vec_splat(scanIndices_01, 0);
 464
 465
 466         vec_ste(scanIndices_01, 0, &lastNonZeroChar);
 467
 468         lastNonZero = lastNonZeroChar;
 469
 470         // While the data is still in vectors we check for the transpose IDCT permute
 471         // and handle it using the vector unit if we can.  This is the permute used
 472         // by the altivec idct, so it is common when using the altivec dct.
 473
 474         if ((lastNonZero > 0) && (s->dsp.idct_permutation_type == FF_TRANSPOSE_IDCT_PERM))
 475         {
 476             TRANSPOSE8(data0, data1, data2, data3, data4, data5, data6, data7);
 477         }
 478
 479         vec_st(data0, 0, data);
 480         vec_st(data1, 16, data);
 481         vec_st(data2, 32, data);
 482         vec_st(data3, 48, data);
 483         vec_st(data4, 64, data);
 484         vec_st(data5, 80, data);
 485         vec_st(data6, 96, data);
 486         vec_st(data7, 112, data);
 487         }
 488     }
 489
 490     // special handling of block[0]
 491     if (s->mb_intra)
 492     {
 493         if (!s->h263_aic)
 494         {
 495             if (n < 4)
 496                 oldBaseValue /= s->y_dc_scale;
 497             else
 498                 oldBaseValue /= s->c_dc_scale;
 499         }
 500
 501         // Divide by 8, rounding the result
 502         data[0] = (oldBaseValue + 4) >> 3;
 503     }
 504
 505     // We handled the tranpose permutation above and we don't
 506     // need to permute the "no" permutation case.
 507     if ((lastNonZero > 0) &&
 508         (s->dsp.idct_permutation_type != FF_TRANSPOSE_IDCT_PERM) &&
 509         (s->dsp.idct_permutation_type != FF_NO_IDCT_PERM))
 510     {
 511         ff_block_permute(data, s->dsp.idct_permutation,
 512                 s->intra_scantable.scantable, lastNonZero);
 513     }
 514
 515     return lastNonZero;
 516 }
 517 #undef FOUROF
 518
 519 /*
 520   AltiVec version of dct_unquantize_h263
 521   this code assumes `block' is 16 bytes-aligned
 522 */
 523 void dct_unquantize_h263_altivec(MpegEncContext *s,
 524                                  DCTELEM *block, int n, int qscale)
 525 {
 526 POWERPC_PERF_DECLARE(altivec_dct_unquantize_h263_num, 1);
 527     int i, level, qmul, qadd;
 528     int nCoeffs;
 529
 530     assert(s->block_last_index[n]>=0);
 531
 532 POWERPC_PERF_START_COUNT(altivec_dct_unquantize_h263_num, 1);
 533
 534     qadd = (qscale - 1) | 1;
 535     qmul = qscale << 1;
 536
 537     if (s->mb_intra) {
 538         if (!s->h263_aic) {
 539             if (n < 4)
 540                 block[0] = block[0] * s->y_dc_scale;
 541             else
 542                 block[0] = block[0] * s->c_dc_scale;
 543         }else
 544             qadd = 0;
 545         i = 1;
 546         nCoeffs= 63; //does not allways use zigzag table
 547     } else {
 548         i = 0;
 549         nCoeffs= s->intra_scantable.raster_end[ s->block_last_index[n] ];
 550     }
 551
 552 #ifdef ALTIVEC_USE_REFERENCE_C_CODE
 553     for(;i<=nCoeffs;i++) {
 554         level = block[i];
 555         if (level) {
 556             if (level < 0) {
 557                 level = level * qmul - qadd;
 558             } else {
 559                 level = level * qmul + qadd;
 560             }
 561             block[i] = level;
 562         }
 563     }
 564 #else /* ALTIVEC_USE_REFERENCE_C_CODE */
 565     {
 566       register const_vector signed short vczero = (const_vector signed short)vec_splat_s16(0);
 567       short __attribute__ ((aligned(16))) qmul8[] =
 568           {
 569             qmul, qmul, qmul, qmul,
 570             qmul, qmul, qmul, qmul
 571           };
 572       short __attribute__ ((aligned(16))) qadd8[] =
 573           {
 574             qadd, qadd, qadd, qadd,
 575             qadd, qadd, qadd, qadd
 576           };
 577       short __attribute__ ((aligned(16))) nqadd8[] =
 578           {
 579             -qadd, -qadd, -qadd, -qadd,
 580             -qadd, -qadd, -qadd, -qadd
 581           };
 582       register vector signed short blockv, qmulv, qaddv, nqaddv, temp1;
 583       register vector bool short blockv_null, blockv_neg;
 584       register short backup_0 = block[0];
 585       register int j = 0;
 586
 587       qmulv = vec_ld(0, qmul8);
 588       qaddv = vec_ld(0, qadd8);
 589       nqaddv = vec_ld(0, nqadd8);
 590
 591 #if 0 // block *is* 16 bytes-aligned, it seems.
 592       // first make sure block[j] is 16 bytes-aligned
 593       for(j = 0; (j <= nCoeffs) && ((((unsigned long)block) + (j << 1)) & 0x0000000F) ; j++) {
 594         level = block[j];
 595         if (level) {
 596           if (level < 0) {
 597                 level = level * qmul - qadd;
 598             } else {
 599                 level = level * qmul + qadd;
 600             }
 601             block[j] = level;
 602         }
 603       }
 604 #endif
 605
 606       // vectorize all the 16 bytes-aligned blocks
 607       // of 8 elements
 608       for(; (j + 7) <= nCoeffs ; j+=8)
 609       {
 610         blockv = vec_ld(j << 1, block);
 611         blockv_neg = vec_cmplt(blockv, vczero);
 612         blockv_null = vec_cmpeq(blockv, vczero);
 613         // choose between +qadd or -qadd as the third operand
 614         temp1 = vec_sel(qaddv, nqaddv, blockv_neg);
 615         // multiply & add (block{i,i+7} * qmul [+-] qadd)
 616         temp1 = vec_mladd(blockv, qmulv, temp1);
 617         // put 0 where block[{i,i+7} used to have 0
 618         blockv = vec_sel(temp1, blockv, blockv_null);
 619         vec_st(blockv, j << 1, block);
 620       }
 621
 622       // if nCoeffs isn't a multiple of 8, finish the job
 623       // using good old scalar units.
 624       // (we could do it using a truncated vector,
 625       // but I'm not sure it's worth the hassle)
 626       for(; j <= nCoeffs ; j++) {
 627         level = block[j];
 628         if (level) {
 629           if (level < 0) {
 630                 level = level * qmul - qadd;
 631             } else {
 632                 level = level * qmul + qadd;
 633             }
 634             block[j] = level;
 635         }
 636       }
 637
 638       if (i == 1)
 639       { // cheat. this avoid special-casing the first iteration
 640         block[0] = backup_0;
 641       }
 642     }
 643 #endif /* ALTIVEC_USE_REFERENCE_C_CODE */
 644
 645 POWERPC_PERF_STOP_COUNT(altivec_dct_unquantize_h263_num, nCoeffs == 63);
 646 }