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_expression_flattening.cpp
26 *
27 * Takes the leaves of expression trees and makes them dereferences of
28 * assignments of the leaves to temporaries, according to a predicate.
29 *
30 * This is used for automatic function inlining, where we want to take
31 * an expression containing a call and move the call out to its own
32 * assignment so that we can inline it at the appropriate place in the
33 * instruction stream.
34 */
35
36#include "ir.h"
37#include "ir_visitor.h"
38#include "ir_rvalue_visitor.h"
39#include "ir_expression_flattening.h"
40#include "glsl_types.h"
41
42class ir_expression_flattening_visitor : public ir_rvalue_visitor {
43public:
44   ir_expression_flattening_visitor(bool (*predicate)(ir_instruction *ir))
45   {
46      this->predicate = predicate;
47   }
48
49   virtual ~ir_expression_flattening_visitor()
50   {
51      /* empty */
52   }
53
54   void handle_rvalue(ir_rvalue **rvalue);
55   bool (*predicate)(ir_instruction *ir);
56};
57
58void
59do_expression_flattening(exec_list *instructions,
60			 bool (*predicate)(ir_instruction *ir))
61{
62   ir_expression_flattening_visitor v(predicate);
63
64   foreach_iter(exec_list_iterator, iter, *instructions) {
65      ir_instruction *ir = (ir_instruction *)iter.get();
66
67      ir->accept(&v);
68   }
69}
70
71void
72ir_expression_flattening_visitor::handle_rvalue(ir_rvalue **rvalue)
73{
74   ir_variable *var;
75   ir_assignment *assign;
76   ir_rvalue *ir = *rvalue;
77
78   if (!ir || !this->predicate(ir))
79      return;
80
81   void *ctx = hieralloc_parent(ir);
82
83   var = new(ctx) ir_variable(ir->type, "flattening_tmp", ir_var_temporary);
84   base_ir->insert_before(var);
85
86   assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(var),
87				   ir,
88				   NULL);
89   base_ir->insert_before(assign);
90
91   *rvalue = new(ctx) ir_dereference_variable(var);
92}
93