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_noop_swizzle.cpp
26 *
27 * If a swizzle doesn't change the order or count of components, then
28 * remove the swizzle so that other optimization passes see the value
29 * behind it.
30 */
31
32 #include "ir.h"
33 #include "ir_visitor.h"
34 #include "ir_rvalue_visitor.h"
35 #include "compiler/glsl_types.h"
36
37 namespace {
38
39 class ir_noop_swizzle_visitor : public ir_rvalue_visitor {
40 public:
ir_noop_swizzle_visitor()41 ir_noop_swizzle_visitor()
42 {
43 this->progress = false;
44 }
45
46 void handle_rvalue(ir_rvalue **rvalue);
47 bool progress;
48 };
49
50 } /* unnamed namespace */
51
52 void
handle_rvalue(ir_rvalue ** rvalue)53 ir_noop_swizzle_visitor::handle_rvalue(ir_rvalue **rvalue)
54 {
55 if (!*rvalue)
56 return;
57
58 ir_swizzle *swiz = (*rvalue)->as_swizzle();
59 if (!swiz || swiz->type != swiz->val->type)
60 return;
61
62 int elems = swiz->val->type->vector_elements;
63 if (swiz->mask.x != 0)
64 return;
65 if (elems >= 2 && swiz->mask.y != 1)
66 return;
67 if (elems >= 3 && swiz->mask.z != 2)
68 return;
69 if (elems >= 4 && swiz->mask.w != 3)
70 return;
71
72 this->progress = true;
73 *rvalue = swiz->val;
74 }
75
76 bool
do_noop_swizzle(exec_list * instructions)77 do_noop_swizzle(exec_list *instructions)
78 {
79 ir_noop_swizzle_visitor v;
80 visit_list_elements(&v, instructions);
81
82 return v.progress;
83 }
84