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_texture_projection.cpp
26 *
27 * IR lower pass to perform the division of texture coordinates by the texture
28 * projector if present.
29 *
30 * Many GPUs have a texture sampling opcode that takes the projector
31 * and does the divide internally, thus the presence of the projector
32 * in the IR. For GPUs that don't, this saves the driver needing the
33 * logic for handling the divide.
34 *
35 * \author Eric Anholt <eric@anholt.net>
36 */
37
38 #include "ir.h"
39
40 class lower_texture_projection_visitor : public ir_hierarchical_visitor {
41 public:
lower_texture_projection_visitor()42 lower_texture_projection_visitor()
43 {
44 progress = false;
45 }
46
47 ir_visitor_status visit_leave(ir_texture *ir);
48
49 bool progress;
50 };
51
52 ir_visitor_status
visit_leave(ir_texture * ir)53 lower_texture_projection_visitor::visit_leave(ir_texture *ir)
54 {
55 if (!ir->projector)
56 return visit_continue;
57
58 void *mem_ctx = ralloc_parent(ir);
59
60 ir_variable *var = new(mem_ctx) ir_variable(ir->projector->type,
61 "projector", ir_var_auto);
62 base_ir->insert_before(var);
63 ir_dereference *deref = new(mem_ctx) ir_dereference_variable(var);
64 ir_expression *expr = new(mem_ctx) ir_expression(ir_unop_rcp,
65 ir->projector->type,
66 ir->projector,
67 NULL);
68 ir_assignment *assign = new(mem_ctx) ir_assignment(deref, expr, NULL);
69 base_ir->insert_before(assign);
70
71 deref = new(mem_ctx) ir_dereference_variable(var);
72 ir->coordinate = new(mem_ctx) ir_expression(ir_binop_mul,
73 ir->coordinate->type,
74 ir->coordinate,
75 deref);
76
77 if (ir->shadow_comparitor) {
78 deref = new(mem_ctx) ir_dereference_variable(var);
79 ir->shadow_comparitor = new(mem_ctx) ir_expression(ir_binop_mul,
80 ir->shadow_comparitor->type,
81 ir->shadow_comparitor,
82 deref);
83 }
84
85 ir->projector = NULL;
86
87 progress = true;
88 return visit_continue;
89 }
90
91 bool
do_lower_texture_projection(exec_list * instructions)92 do_lower_texture_projection(exec_list *instructions)
93 {
94 lower_texture_projection_visitor v;
95
96 visit_list_elements(&v, instructions);
97
98 return v.progress;
99 }
100