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 lower_vec_index_to_swizzle.cpp
26 *
27 * Turns constant indexing into vector types to swizzles. This will
28 * let other swizzle-aware optimization passes catch these constructs,
29 * and codegen backends not have to worry about this case.
30 */
31
32 #include "ir.h"
33 #include "ir_visitor.h"
34 #include "ir_optimization.h"
35 #include "glsl_types.h"
36
37 /**
38 * Visitor class for replacing expressions with ir_constant values.
39 */
40
41 class ir_vec_index_to_swizzle_visitor : public ir_hierarchical_visitor {
42 public:
ir_vec_index_to_swizzle_visitor()43 ir_vec_index_to_swizzle_visitor()
44 {
45 progress = false;
46 }
47
48 ir_rvalue *convert_vec_index_to_swizzle(ir_rvalue *val);
49
50 virtual ir_visitor_status visit_enter(ir_expression *);
51 virtual ir_visitor_status visit_enter(ir_swizzle *);
52 virtual ir_visitor_status visit_enter(ir_assignment *);
53 virtual ir_visitor_status visit_enter(ir_return *);
54 virtual ir_visitor_status visit_enter(ir_call *);
55 virtual ir_visitor_status visit_enter(ir_if *);
56
57 bool progress;
58 };
59
60 ir_rvalue *
convert_vec_index_to_swizzle(ir_rvalue * ir)61 ir_vec_index_to_swizzle_visitor::convert_vec_index_to_swizzle(ir_rvalue *ir)
62 {
63 ir_dereference_array *deref = ir->as_dereference_array();
64 ir_constant *ir_constant;
65
66 if (!deref)
67 return ir;
68
69 if (deref->array->type->is_matrix() || deref->array->type->is_array())
70 return ir;
71
72 assert(deref->array_index->type->base_type == GLSL_TYPE_INT);
73 ir_constant = deref->array_index->constant_expression_value();
74 if (!ir_constant)
75 return ir;
76
77 void *ctx = hieralloc_parent(ir);
78 this->progress = true;
79 return new(ctx) ir_swizzle(deref->array,
80 ir_constant->value.i[0], 0, 0, 0, 1);
81 }
82
83 ir_visitor_status
visit_enter(ir_expression * ir)84 ir_vec_index_to_swizzle_visitor::visit_enter(ir_expression *ir)
85 {
86 unsigned int i;
87
88 for (i = 0; i < ir->get_num_operands(); i++) {
89 ir->operands[i] = convert_vec_index_to_swizzle(ir->operands[i]);
90 }
91
92 return visit_continue;
93 }
94
95 ir_visitor_status
visit_enter(ir_swizzle * ir)96 ir_vec_index_to_swizzle_visitor::visit_enter(ir_swizzle *ir)
97 {
98 /* Can't be hit from normal GLSL, since you can't swizzle a scalar (which
99 * the result of indexing a vector is. But maybe at some point we'll end up
100 * using swizzling of scalars for vector construction.
101 */
102 ir->val = convert_vec_index_to_swizzle(ir->val);
103
104 return visit_continue;
105 }
106
107 ir_visitor_status
visit_enter(ir_assignment * ir)108 ir_vec_index_to_swizzle_visitor::visit_enter(ir_assignment *ir)
109 {
110 ir->set_lhs(convert_vec_index_to_swizzle(ir->lhs));
111 ir->rhs = convert_vec_index_to_swizzle(ir->rhs);
112
113 return visit_continue;
114 }
115
116 ir_visitor_status
visit_enter(ir_call * ir)117 ir_vec_index_to_swizzle_visitor::visit_enter(ir_call *ir)
118 {
119 foreach_iter(exec_list_iterator, iter, *ir) {
120 ir_rvalue *param = (ir_rvalue *)iter.get();
121 ir_rvalue *new_param = convert_vec_index_to_swizzle(param);
122
123 if (new_param != param) {
124 param->replace_with(new_param);
125 }
126 }
127
128 return visit_continue;
129 }
130
131 ir_visitor_status
visit_enter(ir_return * ir)132 ir_vec_index_to_swizzle_visitor::visit_enter(ir_return *ir)
133 {
134 if (ir->value) {
135 ir->value = convert_vec_index_to_swizzle(ir->value);
136 }
137
138 return visit_continue;
139 }
140
141 ir_visitor_status
visit_enter(ir_if * ir)142 ir_vec_index_to_swizzle_visitor::visit_enter(ir_if *ir)
143 {
144 ir->condition = convert_vec_index_to_swizzle(ir->condition);
145
146 return visit_continue;
147 }
148
149 bool
do_vec_index_to_swizzle(exec_list * instructions)150 do_vec_index_to_swizzle(exec_list *instructions)
151 {
152 ir_vec_index_to_swizzle_visitor v;
153
154 v.run(instructions);
155
156 return v.progress;
157 }
158