src/mesa/drivers/dri/r300/compiler/radeon_program_pair.c

   1 /*
   2  * Copyright (C) 2008-2009 Nicolai Haehnle.
   3  *
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining
   7  * a copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sublicense, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial
  16  * portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  21  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  22  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  */
  27
  28 #include "radeon_program_pair.h"
  29
  30
  31 /**
  32  * Return the source slot where we installed the given register access,
  33  * or -1 if no slot was free anymore.
  34  */
  35 int rc_pair_alloc_source(struct rc_pair_instruction *pair,
  36         unsigned int rgb, unsigned int alpha,
  37         rc_register_file file, unsigned int index)
  38 {
  39         int candidate = -1;
  40         int candidate_quality = -1;
  41         int i;
  42
  43         if ((!rgb && !alpha) || file == RC_FILE_NONE)
  44                 return 0;
  45
  46         for(i = 0; i < 3; ++i) {
  47                 int q = 0;
  48                 if (rgb) {
  49                         if (pair->RGB.Src[i].Used) {
  50                                 if (pair->RGB.Src[i].File != file ||
  51                                     pair->RGB.Src[i].Index != index)
  52                                         continue;
  53                                 q++;
  54                         }
  55                 }
  56                 if (alpha) {
  57                         if (pair->Alpha.Src[i].Used) {
  58                                 if (pair->Alpha.Src[i].File != file ||
  59                                     pair->Alpha.Src[i].Index != index)
  60                                         continue;
  61                                 q++;
  62                         }
  63                 }
  64                 if (q > candidate_quality) {
  65                         candidate_quality = q;
  66                         candidate = i;
  67                 }
  68         }
  69
  70         if (candidate >= 0) {
  71                 if (rgb) {
  72                         pair->RGB.Src[candidate].Used = 1;
  73                         pair->RGB.Src[candidate].File = file;
  74                         pair->RGB.Src[candidate].Index = index;
  75                 }
  76                 if (alpha) {
  77                         pair->Alpha.Src[candidate].Used = 1;
  78                         pair->Alpha.Src[candidate].File = file;
  79                         pair->Alpha.Src[candidate].Index = index;
  80                 }
  81         }
  82
  83         return candidate;
  84 }