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
35class ir_swizzle_swizzle_visitor : public ir_hierarchical_visitor {
36public:
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
47ir_visitor_status
48ir_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 */
85bool
86do_swizzle_swizzle(exec_list *instructions)
87{
88   ir_swizzle_swizzle_visitor v;
89
90   v.run(instructions);
91
92   return v.progress;
93}
94