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 ir_mod_to_floor.cpp
26 *
27 * Breaks an ir_unop_mod expression down to (op1 * fract(op0 / op1))
28 *
29 * Many GPUs don't have a MOD instruction (945 and 965 included), and
30 * if we have to break it down like this anyway, it gives an
31 * opportunity to do things like constant fold the (1.0 / op1) easily.
32 */
33
34 #include "ir.h"
35
36 class ir_mod_to_fract_visitor : public ir_hierarchical_visitor {
37 public:
ir_mod_to_fract_visitor()38 ir_mod_to_fract_visitor()
39 {
40 this->made_progress = false;
41 }
42
43 ir_visitor_status visit_leave(ir_expression *);
44
45 bool made_progress;
46 };
47
48 bool
do_mod_to_fract(exec_list * instructions)49 do_mod_to_fract(exec_list *instructions)
50 {
51 ir_mod_to_fract_visitor v;
52
53 visit_list_elements(&v, instructions);
54 return v.made_progress;
55 }
56
57 ir_visitor_status
visit_leave(ir_expression * ir)58 ir_mod_to_fract_visitor::visit_leave(ir_expression *ir)
59 {
60 if (ir->operation != ir_binop_mod)
61 return visit_continue;
62
63 ir_variable *temp = new(ir) ir_variable(ir->operands[1]->type, "mod_b",
64 ir_var_temporary);
65 this->base_ir->insert_before(temp);
66
67 ir_assignment *assign;
68 ir_rvalue *expr;
69
70 assign = new(ir) ir_assignment(new(ir) ir_dereference_variable(temp),
71 ir->operands[1], NULL);
72 this->base_ir->insert_before(assign);
73
74 expr = new(ir) ir_expression(ir_binop_div,
75 ir->operands[0]->type,
76 ir->operands[0],
77 new(ir) ir_dereference_variable(temp));
78
79 expr = new(ir) ir_expression(ir_unop_fract,
80 ir->operands[0]->type,
81 expr,
82 NULL);
83
84 ir->operation = ir_binop_mul;
85 ir->operands[0] = new(ir) ir_dereference_variable(temp);
86 ir->operands[1] = expr;
87 this->made_progress = true;
88
89 return visit_continue;
90 }
91