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
24 /**
25 * \file lower_offset_array.cpp
26 *
27 * IR lower pass to decompose ir_texture ir_tg4 with an array of offsets
28 * into four ir_tg4s with a single ivec2 offset, select the .w component of each,
29 * and return those four values packed into a gvec4.
30 *
31 * \author Chris Forbes <chrisf@ijw.co.nz>
32 */
33
34 #include "compiler/glsl_types.h"
35 #include "ir.h"
36 #include "ir_builder.h"
37 #include "ir_optimization.h"
38 #include "ir_rvalue_visitor.h"
39
40 using namespace ir_builder;
41
42 class lower_offset_array_visitor : public ir_rvalue_visitor {
43 public:
lower_offset_array_visitor()44 lower_offset_array_visitor()
45 {
46 progress = false;
47 }
48
49 void handle_rvalue(ir_rvalue **rv);
50
51 bool progress;
52 };
53
54 void
handle_rvalue(ir_rvalue ** rv)55 lower_offset_array_visitor::handle_rvalue(ir_rvalue **rv)
56 {
57 if (*rv == NULL || (*rv)->ir_type != ir_type_texture)
58 return;
59
60 ir_texture *ir = (ir_texture *) *rv;
61 if (ir->op != ir_tg4 || !ir->offset || !ir->offset->type->is_array())
62 return;
63
64 void *mem_ctx = ralloc_parent(ir);
65
66 ir_variable *var =
67 new (mem_ctx) ir_variable(ir->type, "result", ir_var_temporary);
68 base_ir->insert_before(var);
69
70 for (int i = 0; i < 4; i++) {
71 ir_texture *tex = ir->clone(mem_ctx, NULL);
72 tex->offset = new (mem_ctx) ir_dereference_array(tex->offset,
73 new (mem_ctx) ir_constant(i));
74
75 base_ir->insert_before(assign(var, swizzle_w(tex), 1 << i));
76 }
77
78 *rv = new (mem_ctx) ir_dereference_variable(var);
79
80 progress = true;
81 }
82
83 bool
lower_offset_arrays(exec_list * instructions)84 lower_offset_arrays(exec_list *instructions)
85 {
86 lower_offset_array_visitor v;
87
88 visit_list_elements(&v, instructions);
89
90 return v.progress;
91 }
92