text: // Copyright 2014 Google Inc. All Rights Reserved.
  //
  // Use of this source code is governed by a BSD-style license
  // that can be found in the COPYING file in the root of the source
  // tree. An additional intellectual property rights grant can be found
  // in the file PATENTS. All contributing project authors may
  // be found in the AUTHORS file in the root of the source tree.
  // -----------------------------------------------------------------------------
  //
  // MIPS version of rescaling functions
  //
  // Author(s): Djordje Pesut (djordje.pesut@imgtec.com)
  
  #include "src/dsp/dsp.h"
  
  #if defined(WEBP_USE_MIPS_DSP_R2) && !defined(WEBP_REDUCE_SIZE)
  
  #include <assert.h>
  #include "src/utils/rescaler_utils.h"
  
  #define ROUNDER (WEBP_RESCALER_ONE >> 1)
  #define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
  #define MULT_FIX_FLOOR(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
  
  //------------------------------------------------------------------------------
  // Row export
  
  #if 0  // disabled for now. TODO(skal): make match the C-code
  static void ExportRowShrink_MIPSdspR2(WebPRescaler* const wrk) {
    int i;
    const int x_out_max = wrk->dst_width * wrk->num_channels;
    uint8_t* dst = wrk->dst;
    rescaler_t* irow = wrk->irow;
    const rescaler_t* frow = wrk->frow;
    const int yscale = wrk->fy_scale * (-wrk->y_accum);
    int temp0, temp1, temp2, temp3, temp4, temp5, loop_end;
    const int temp7 = (int)wrk->fxy_scale;
    const int temp6 = (x_out_max & ~0x3) << 2;
    assert(!WebPRescalerOutputDone(wrk));
    assert(wrk->y_accum <= 0);
    assert(!wrk->y_expand);
    assert(wrk->fxy_scale != 0);
    if (yscale) {
      if (x_out_max >= 4) {
        int temp8, temp9, temp10, temp11;
        __asm__ volatile (
          "li       %[temp3],    0x10000                    \n\t"
          "li       %[temp4],    0x8000                     \n\t"
          "addu     %[loop_end], %[frow],     %[temp6]      \n\t"
        "1:                                                 \n\t"
          "lw       %[temp0],    0(%[frow])                 \n\t"
          "lw       %[temp1],    4(%[frow])                 \n\t"
          "lw       %[temp2],    8(%[frow])                 \n\t"
          "lw       %[temp5],    12(%[frow])                \n\t"
          "mult     $ac0,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac0,        %[temp0],    %[yscale]     \n\t"
          "mult     $ac1,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac1,        %[temp1],    %[yscale]     \n\t"
          "mult     $ac2,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac2,        %[temp2],    %[yscale]     \n\t"
          "mult     $ac3,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac3,        %[temp5],    %[yscale]     \n\t"
          "addiu    %[frow],     %[frow],     16            \n\t"
          "mfhi     %[temp0],    $ac0                       \n\t"
          "mfhi     %[temp1],    $ac1                       \n\t"
          "mfhi     %[temp2],    $ac2                       \n\t"
          "mfhi     %[temp5],    $ac3                       \n\t"
          "lw       %[temp8],    0(%[irow])                 \n\t"
          "lw       %[temp9],    4(%[irow])                 \n\t"
          "lw       %[temp10],   8(%[irow])                 \n\t"
          "lw       %[temp11],   12(%[irow])                \n\t"
          "addiu    %[dst],      %[dst],      4             \n\t"
          "addiu    %[irow],     %[irow],     16            \n\t"
          "subu     %[temp8],    %[temp8],    %[temp0]      \n\t"
          "subu     %[temp9],    %[temp9],    %[temp1]      \n\t"
          "subu     %[temp10],   %[temp10],   %[temp2]      \n\t"
          "subu     %[temp11],   %[temp11],   %[temp5]      \n\t"
          "mult     $ac0,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac0,        %[temp8],    %[temp7]      \n\t"
          "mult     $ac1,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac1,        %[temp9],    %[temp7]      \n\t"
          "mult     $ac2,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac2,        %[temp10],   %[temp7]      \n\t"
          "mult     $ac3,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac3,        %[temp11],   %[temp7]      \n\t"
          "mfhi     %[temp8],    $ac0                       \n\t"
          "mfhi     %[temp9],    $ac1                       \n\t"
          "mfhi     %[temp10],   $ac2                       \n\t"
          "mfhi     %[temp11],   $ac3                       \n\t"
          "sw       %[temp0],    -16(%[irow])               \n\t"
          "sw       %[temp1],    -12(%[irow])               \n\t"
          "sw       %[temp2],    -8(%[irow])                \n\t"
          "sw       %[temp5],    -4(%[irow])                \n\t"
          "sb       %[temp8],    -4(%[dst])                 \n\t"
          "sb       %[temp9],    -3(%[dst])                 \n\t"
          "sb       %[temp10],   -2(%[dst])                 \n\t"
          "sb       %[temp11],   -1(%[dst])                 \n\t"
          "bne      %[frow],     %[loop_end], 1b            \n\t"
          : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp3]"=&r"(temp3),
            [temp4]"=&r"(temp4), [temp5]"=&r"(temp5), [frow]"+r"(frow),
            [irow]"+r"(irow), [dst]"+r"(dst), [loop_end]"=&r"(loop_end),
            [temp8]"=&r"(temp8), [temp9]"=&r"(temp9), [temp10]"=&r"(temp10),
            [temp11]"=&r"(temp11), [temp2]"=&r"(temp2)
          : [temp7]"r"(temp7), [yscale]"r"(yscale), [temp6]"r"(temp6)
          : "memory", "hi", "lo", "$ac1hi", "$ac1lo",
            "$ac2hi", "$ac2lo", "$ac3hi", "$ac3lo"
        );
      }
      for (i = 0; i < (x_out_max & 0x3); ++i) {
        const uint32_t frac = (uint32_t)MULT_FIX_FLOOR(*frow++, yscale);
        const int v = (int)MULT_FIX(*irow - frac, wrk->fxy_scale);
        *dst++ = (v > 255) ? 255u : (uint8_t)v;
        *irow++ = frac;   // new fractional start
      }
    } else {
      if (x_out_max >= 4) {
        __asm__ volatile (
          "li       %[temp3],    0x10000                    \n\t"
          "li       %[temp4],    0x8000                     \n\t"
          "addu     %[loop_end], %[irow],     %[temp6]      \n\t"
        "1:                                                 \n\t"
          "lw       %[temp0],    0(%[irow])                 \n\t"
          "lw       %[temp1],    4(%[irow])                 \n\t"
          "lw       %[temp2],    8(%[irow])                 \n\t"
          "lw       %[temp5],    12(%[irow])                \n\t"
          "addiu    %[dst],      %[dst],      4             \n\t"
          "addiu    %[irow],     %[irow],     16            \n\t"
          "mult     $ac0,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac0,        %[temp0],    %[temp7]      \n\t"
          "mult     $ac1,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac1,        %[temp1],    %[temp7]      \n\t"
          "mult     $ac2,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac2,        %[temp2],    %[temp7]      \n\t"
          "mult     $ac3,        %[temp3],    %[temp4]      \n\t"
          "maddu    $ac3,        %[temp5],    %[temp7]      \n\t"
          "mfhi     %[temp0],    $ac0                       \n\t"
          "mfhi     %[temp1],    $ac1                       \n\t"
          "mfhi     %[temp2],    $ac2                       \n\t"
          "mfhi     %[temp5],    $ac3                       \n\t"
          "sw       $zero,       -16(%[irow])               \n\t"
          "sw       $zero,       -12(%[irow])               \n\t"
          "sw       $zero,       -8(%[irow])                \n\t"
          "sw       $zero,       -4(%[irow])                \n\t"
          "sb       %[temp0],    -4(%[dst])                 \n\t"
          "sb       %[temp1],    -3(%[dst])                 \n\t"
          "sb       %[temp2],    -2(%[dst])                 \n\t"
          "sb       %[temp5],    -1(%[dst])                 \n\t"
          "bne      %[irow],     %[loop_end], 1b            \n\t"
          : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp3]"=&r"(temp3),
            [temp4]"=&r"(temp4), [temp5]"=&r"(temp5), [irow]"+r"(irow),
            [dst]"+r"(dst), [loop_end]"=&r"(loop_end), [temp2]"=&r"(temp2)
          : [temp7]"r"(temp7), [temp6]"r"(temp6)
          : "memory", "hi", "lo", "$ac1hi", "$ac1lo",
            "$ac2hi", "$ac2lo", "$ac3hi", "$ac3lo"
        );
      }
      for (i = 0; i < (x_out_max & 0x3); ++i) {
        const int v = (int)MULT_FIX_FLOOR(*irow, wrk->fxy_scale);
        *dst++ = (v > 255) ? 255u : (uint8_t)v;
        *irow++ = 0;
      }
    }
  }
  #endif  // 0
  
  static void ExportRowExpand_MIPSdspR2(WebPRescaler* const wrk) {
    int i;
    uint8_t* dst = wrk->dst;
    rescaler_t* irow = wrk->irow;
    const int x_out_max = wrk->dst_width * wrk->num_channels;
    const rescaler_t* frow = wrk->frow;
    int temp0, temp1, temp2, temp3, temp4, temp5, loop_end;
    const int temp6 = (x_out_max & ~0x3) << 2;
    const int temp7 = (int)wrk->fy_scale;
    assert(!WebPRescalerOutputDone(wrk));
    assert(wrk->y_accum <= 0);
    assert(wrk->y_expand);
    assert(wrk->y_sub != 0);
    if (wrk->y_accum == 0) {
      if (x_out_max >= 4) {
        __asm__ volatile (
          "li       %[temp4],    0x10000                    \n\t"
          "li       %[temp5],    0x8000                     \n\t"
          "addu     %[loop_end], %[frow],     %[temp6]      \n\t"
        "1:                                                 \n\t"
          "lw       %[temp0],    0(%[frow])                 \n\t"
          "lw       %[temp1],    4(%[frow])                 \n\t"
          "lw       %[temp2],    8(%[frow])                 \n\t"
          "lw       %[temp3],    12(%[frow])                \n\t"
          "addiu    %[dst],      %[dst],      4             \n\t"
          "addiu    %[frow],     %[frow],     16            \n\t"
          "mult     $ac0,        %[temp4],    %[temp5]      \n\t"
          "maddu    $ac0,        %[temp0],    %[temp7]      \n\t"
          "mult     $ac1,        %[temp4],    %[temp5]      \n\t"
          "maddu    $ac1,        %[temp1],    %[temp7]      \n\t"
          "mult     $ac2,        %[temp4],    %[temp5]      \n\t"
          "maddu    $ac2,        %[temp2],    %[temp7]      \n\t"
          "mult     $ac3,        %[temp4],    %[temp5]      \n\t"
          "maddu    $ac3,        %[temp3],    %[temp7]      \n\t"
          "mfhi     %[temp0],    $ac0                       \n\t"
          "mfhi     %[temp1],    $ac1                       \n\t"
          "mfhi     %[temp2],    $ac2                       \n\t"
          "mfhi     %[temp3],    $ac3                       \n\t"
          "sb       %[temp0],    -4(%[dst])                 \n\t"
          "sb       %[temp1],    -3(%[dst])                 \n\t"
          "sb       %[temp2],    -2(%[dst])                 \n\t"
          "sb       %[temp3],    -1(%[dst])                 \n\t"
          "bne      %[frow],     %[loop_end], 1b            \n\t"
          : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp3]"=&r"(temp3),
            [temp4]"=&r"(temp4), [temp5]"=&r"(temp5), [frow]"+r"(frow),
            [dst]"+r"(dst), [loop_end]"=&r"(loop_end), [temp2]"=&r"(temp2)
          : [temp7]"r"(temp7), [temp6]"r"(temp6)
          : "memory", "hi", "lo", "$ac1hi", "$ac1lo",
            "$ac2hi", "$ac2lo", "$ac3hi", "$ac3lo"
        );
      }
      for (i = 0; i < (x_out_max & 0x3); ++i) {
        const uint32_t J = *frow++;
        const int v = (int)MULT_FIX(J, wrk->fy_scale);
        *dst++ = (v > 255) ? 255u : (uint8_t)v;
      }
    } else {
      const uint32_t B = WEBP_RESCALER_FRAC(-wrk->y_accum, wrk->y_sub);
      const uint32_t A = (uint32_t)(WEBP_RESCALER_ONE - B);
      if (x_out_max >= 4) {
        int temp8, temp9, temp10, temp11;
        __asm__ volatile (
          "li       %[temp8],    0x10000                    \n\t"
          "li       %[temp9],    0x8000                     \n\t"
          "addu     %[loop_end], %[frow],     %[temp6]      \n\t"
        "1:                                                 \n\t"
          "lw       %[temp0],    0(%[frow])                 \n\t"
          "lw       %[temp1],    4(%[frow])                 \n\t"
          "lw       %[temp2],    8(%[frow])                 \n\t"
          "lw       %[temp3],    12(%[frow])                \n\t"
          "lw       %[temp4],    0(%[irow])                 \n\t"
          "lw       %[temp5],    4(%[irow])                 \n\t"
          "lw       %[temp10],   8(%[irow])                 \n\t"
          "lw       %[temp11],   12(%[irow])                \n\t"
          "addiu    %[dst],      %[dst],      4             \n\t"
          "mult     $ac0,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac0,        %[A],        %[temp0]      \n\t"
          "maddu    $ac0,        %[B],        %[temp4]      \n\t"
          "mult     $ac1,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac1,        %[A],        %[temp1]      \n\t"
          "maddu    $ac1,        %[B],        %[temp5]      \n\t"
          "mult     $ac2,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac2,        %[A],        %[temp2]      \n\t"
          "maddu    $ac2,        %[B],        %[temp10]     \n\t"
          "mult     $ac3,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac3,        %[A],        %[temp3]      \n\t"
          "maddu    $ac3,        %[B],        %[temp11]     \n\t"
          "addiu    %[frow],     %[frow],     16            \n\t"
          "addiu    %[irow],     %[irow],     16            \n\t"
          "mfhi     %[temp0],    $ac0                       \n\t"
          "mfhi     %[temp1],    $ac1                       \n\t"
          "mfhi     %[temp2],    $ac2                       \n\t"
          "mfhi     %[temp3],    $ac3                       \n\t"
          "mult     $ac0,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac0,        %[temp0],    %[temp7]      \n\t"
          "mult     $ac1,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac1,        %[temp1],    %[temp7]      \n\t"
          "mult     $ac2,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac2,        %[temp2],    %[temp7]      \n\t"
          "mult     $ac3,        %[temp8],    %[temp9]      \n\t"
          "maddu    $ac3,        %[temp3],    %[temp7]      \n\t"
          "mfhi     %[temp0],    $ac0                       \n\t"
          "mfhi     %[temp1],    $ac1                       \n\t"
          "mfhi     %[temp2],    $ac2                       \n\t"
          "mfhi     %[temp3],    $ac3                       \n\t"
          "sb       %[temp0],    -4(%[dst])                 \n\t"
          "sb       %[temp1],    -3(%[dst])                 \n\t"
          "sb       %[temp2],    -2(%[dst])                 \n\t"
          "sb       %[temp3],    -1(%[dst])                 \n\t"
          "bne      %[frow],     %[loop_end], 1b            \n\t"
          : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp3]"=&r"(temp3),
            [temp4]"=&r"(temp4), [temp5]"=&r"(temp5), [frow]"+r"(frow),
            [irow]"+r"(irow), [dst]"+r"(dst), [loop_end]"=&r"(loop_end),
            [temp8]"=&r"(temp8), [temp9]"=&r"(temp9), [temp10]"=&r"(temp10),
            [temp11]"=&r"(temp11), [temp2]"=&r"(temp2)
          : [temp7]"r"(temp7), [temp6]"r"(temp6), [A]"r"(A), [B]"r"(B)
          : "memory", "hi", "lo", "$ac1hi", "$ac1lo",
            "$ac2hi", "$ac2lo", "$ac3hi", "$ac3lo"
        );
      }
      for (i = 0; i < (x_out_max & 0x3); ++i) {
        const uint64_t I = (uint64_t)A * *frow++
                         + (uint64_t)B * *irow++;
        const uint32_t J = (uint32_t)((I + ROUNDER) >> WEBP_RESCALER_RFIX);
        const int v = (int)MULT_FIX(J, wrk->fy_scale);
        *dst++ = (v > 255) ? 255u : (uint8_t)v;
      }
    }
  }
  
  #undef MULT_FIX_FLOOR
  #undef MULT_FIX
  #undef ROUNDER
  
  //------------------------------------------------------------------------------
  // Entry point
  
  extern void WebPRescalerDspInitMIPSdspR2(void);
  
  WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitMIPSdspR2(void) {
    WebPRescalerExportRowExpand = ExportRowExpand_MIPSdspR2;
  //  WebPRescalerExportRowShrink = ExportRowShrink_MIPSdspR2;
  }
  
  #else  // !WEBP_USE_MIPS_DSP_R2
  
  WEBP_DSP_INIT_STUB(WebPRescalerDspInitMIPSdspR2)
  
  #endif  // WEBP_USE_MIPS_DSP_R2
  