src/glsl/opt_swizzle_swizzle.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file opt_swizzle_swizzle.cpp
  26  *
  27  * Eliminates the second swizzle in a swizzle chain.
  28  */
  29
  30 #include "ir.h"
  31 #include "ir_visitor.h"
  32 #include "ir_optimization.h"
  33 #include "glsl_types.h"
  34
  35 class ir_swizzle_swizzle_visitor : public ir_hierarchical_visitor {
  36 public:
  37    ir_swizzle_swizzle_visitor()
  38    {
  39       progress = false;
  40    }
  41
  42    virtual ir_visitor_status visit_enter(ir_swizzle *);
  43
  44    bool progress;
  45 };
  46
  47 ir_visitor_status
  48 ir_swizzle_swizzle_visitor::visit_enter(ir_swizzle *ir)
  49 {
  50    int mask2[4];
  51
  52    ir_swizzle *swiz2 = ir->val->as_swizzle();
  53    if (!swiz2)
  54       return visit_continue;
  55
  56    memset(&mask2, 0, sizeof(mask2));
  57    if (swiz2->mask.num_components >= 1)
  58       mask2[0] = swiz2->mask.x;
  59    if (swiz2->mask.num_components >= 2)
  60       mask2[1] = swiz2->mask.y;
  61    if (swiz2->mask.num_components >= 3)
  62       mask2[2] = swiz2->mask.z;
  63    if (swiz2->mask.num_components >= 4)
  64       mask2[3] = swiz2->mask.w;
  65
  66    if (ir->mask.num_components >= 1)
  67       ir->mask.x = mask2[ir->mask.x];
  68    if (ir->mask.num_components >= 2)
  69       ir->mask.y = mask2[ir->mask.y];
  70    if (ir->mask.num_components >= 3)
  71       ir->mask.z = mask2[ir->mask.z];
  72    if (ir->mask.num_components >= 4)
  73       ir->mask.w = mask2[ir->mask.w];
  74
  75    ir->val = swiz2->val;
  76
  77    this->progress = true;
  78
  79    return visit_continue;
  80 }
  81
  82 /**
  83  * Does a copy propagation pass on the code present in the instruction stream.
  84  */
  85 bool
  86 do_swizzle_swizzle(exec_list *instructions)
  87 {
  88    ir_swizzle_swizzle_visitor v;
  89
  90    v.run(instructions);
  91
  92    return v.progress;
  93 }