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 breaking down matrix operations, where it's easier to
31 * create a temporary and work on each of its vector components individually.
32 */
33
34#include "ir.h"
35#include "ir_rvalue_visitor.h"
36#include "ir_expression_flattening.h"
37
38class ir_expression_flattening_visitor : public ir_rvalue_visitor {
39public:
40   ir_expression_flattening_visitor(bool (*predicate)(ir_instruction *ir))
41   {
42      this->predicate = predicate;
43   }
44
45   virtual ~ir_expression_flattening_visitor()
46   {
47      /* empty */
48   }
49
50   void handle_rvalue(ir_rvalue **rvalue);
51   bool (*predicate)(ir_instruction *ir);
52};
53
54void
55do_expression_flattening(exec_list *instructions,
56			 bool (*predicate)(ir_instruction *ir))
57{
58   ir_expression_flattening_visitor v(predicate);
59
60   foreach_in_list(ir_instruction, ir, instructions) {
61      ir->accept(&v);
62   }
63}
64
65void
66ir_expression_flattening_visitor::handle_rvalue(ir_rvalue **rvalue)
67{
68   ir_variable *var;
69   ir_assignment *assign;
70   ir_rvalue *ir = *rvalue;
71
72   if (!ir || !this->predicate(ir))
73      return;
74
75   void *ctx = ralloc_parent(ir);
76
77   var = new(ctx) ir_variable(ir->type, "flattening_tmp", ir_var_temporary);
78   base_ir->insert_before(var);
79
80   assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(var),
81				   ir,
82				   NULL);
83   base_ir->insert_before(assign);
84
85   *rvalue = new(ctx) ir_dereference_variable(var);
86}
87