1 /*
2 * Copyright © 2013 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 #include "ir.h"
24 #include "ir_builder.h"
25 #include "ir_rvalue_visitor.h"
26 #include "ir_optimization.h"
27
28 using namespace ir_builder;
29
30 namespace {
31
32 class vector_insert_visitor : public ir_rvalue_visitor {
33 public:
vector_insert_visitor(bool lower_nonconstant_index)34 vector_insert_visitor(bool lower_nonconstant_index)
35 : progress(false), lower_nonconstant_index(lower_nonconstant_index),
36 remove_assignment(false)
37 {
38 factory.instructions = &factory_instructions;
39 }
40
~vector_insert_visitor()41 virtual ~vector_insert_visitor()
42 {
43 assert(factory_instructions.is_empty());
44 }
45
46 virtual void handle_rvalue(ir_rvalue **rv);
47 virtual ir_visitor_status visit_leave(ir_assignment *expr);
48
49 ir_factory factory;
50 exec_list factory_instructions;
51 bool progress;
52 bool lower_nonconstant_index;
53 bool remove_assignment;
54 };
55
56 } /* anonymous namespace */
57
58 void
handle_rvalue(ir_rvalue ** rv)59 vector_insert_visitor::handle_rvalue(ir_rvalue **rv)
60 {
61 if (*rv == NULL || (*rv)->ir_type != ir_type_expression)
62 return;
63
64 ir_expression *const expr = (ir_expression *) *rv;
65
66 if (likely(expr->operation != ir_triop_vector_insert))
67 return;
68
69 factory.mem_ctx = ralloc_parent(expr);
70
71 ir_constant *const idx =
72 expr->operands[2]->constant_expression_value(factory.mem_ctx);
73 if (idx != NULL) {
74 unsigned index = idx->value.u[0];
75
76 if (index >= expr->operands[0]->type->vector_elements) {
77 /* Section 5.11 (Out-of-Bounds Accesses) of the GLSL 4.60 spec says:
78 *
79 * In the subsections described above for array, vector, matrix and
80 * structure accesses, any out-of-bounds access produced undefined
81 * behavior.... Out-of-bounds writes may be discarded or overwrite
82 * other variables of the active program.
83 */
84 this->remove_assignment = true;
85 this->progress = true;
86 return;
87 }
88
89 /* Replace (vector_insert (vec) (scalar) (index)) with a dereference of
90 * a new temporary. The new temporary gets assigned as
91 *
92 * t = vec
93 * t.mask = scalar
94 *
95 * where mask is the component selected by index.
96 */
97 ir_variable *const temp =
98 factory.make_temp(expr->operands[0]->type, "vec_tmp");
99
100 const int mask = 1 << idx->value.i[0];
101
102 factory.emit(assign(temp, expr->operands[0]));
103 factory.emit(assign(temp, expr->operands[1], mask));
104
105 this->progress = true;
106 *rv = new(factory.mem_ctx) ir_dereference_variable(temp);
107 } else if (this->lower_nonconstant_index) {
108 /* Replace (vector_insert (vec) (scalar) (index)) with a dereference of
109 * a new temporary. The new temporary gets assigned as
110 *
111 * t = vec
112 * if (index == 0)
113 * t.x = scalar
114 * if (index == 1)
115 * t.y = scalar
116 * if (index == 2)
117 * t.z = scalar
118 * if (index == 3)
119 * t.w = scalar
120 */
121 ir_variable *const temp =
122 factory.make_temp(expr->operands[0]->type, "vec_tmp");
123
124 ir_variable *const src_temp =
125 factory.make_temp(expr->operands[1]->type, "src_temp");
126
127 factory.emit(assign(temp, expr->operands[0]));
128 factory.emit(assign(src_temp, expr->operands[1]));
129
130 assert(expr->operands[2]->type == glsl_type::int_type ||
131 expr->operands[2]->type == glsl_type::uint_type);
132
133 for (unsigned i = 0; i < expr->type->vector_elements; i++) {
134 ir_constant *const cmp_index =
135 ir_constant::zero(factory.mem_ctx, expr->operands[2]->type);
136 cmp_index->value.u[0] = i;
137
138 ir_variable *const cmp_result =
139 factory.make_temp(glsl_type::bool_type, "index_condition");
140
141 factory.emit(assign(cmp_result,
142 equal(expr->operands[2]->clone(factory.mem_ctx,
143 NULL),
144 cmp_index)));
145
146 factory.emit(if_tree(cmp_result,
147 assign(temp, src_temp, WRITEMASK_X << i)));
148 }
149
150 this->progress = true;
151 *rv = new(factory.mem_ctx) ir_dereference_variable(temp);
152 }
153
154 base_ir->insert_before(factory.instructions);
155 }
156
157 ir_visitor_status
visit_leave(ir_assignment * ir)158 vector_insert_visitor::visit_leave(ir_assignment *ir)
159 {
160 ir_rvalue_visitor::visit_leave(ir);
161
162 if (this->remove_assignment) {
163 ir->remove();
164 this->remove_assignment = false;
165 }
166
167 return visit_continue;
168 }
169
170 bool
lower_vector_insert(exec_list * instructions,bool lower_nonconstant_index)171 lower_vector_insert(exec_list *instructions, bool lower_nonconstant_index)
172 {
173 vector_insert_visitor v(lower_nonconstant_index);
174
175 visit_list_elements(&v, instructions);
176
177 return v.progress;
178 }
179