1 /*
2  * Copyright © 2010 Intel Corporation
3  *
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5  * copy of this software and associated documentation files (the "Software"),
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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
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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_visitor.h"
36 #include "ir_rvalue_visitor.h"
37 #include "ir_expression_flattening.h"
38 #include "glsl_types.h"
39 
40 class ir_expression_flattening_visitor : public ir_rvalue_visitor {
41 public:
ir_expression_flattening_visitor(bool (* predicate)(ir_instruction * ir))42    ir_expression_flattening_visitor(bool (*predicate)(ir_instruction *ir))
43    {
44       this->predicate = predicate;
45    }
46 
~ir_expression_flattening_visitor()47    virtual ~ir_expression_flattening_visitor()
48    {
49       /* empty */
50    }
51 
52    void handle_rvalue(ir_rvalue **rvalue);
53    bool (*predicate)(ir_instruction *ir);
54 };
55 
56 void
do_expression_flattening(exec_list * instructions,bool (* predicate)(ir_instruction * ir))57 do_expression_flattening(exec_list *instructions,
58 			 bool (*predicate)(ir_instruction *ir))
59 {
60    ir_expression_flattening_visitor v(predicate);
61 
62    foreach_iter(exec_list_iterator, iter, *instructions) {
63       ir_instruction *ir = (ir_instruction *)iter.get();
64 
65       ir->accept(&v);
66    }
67 }
68 
69 void
handle_rvalue(ir_rvalue ** rvalue)70 ir_expression_flattening_visitor::handle_rvalue(ir_rvalue **rvalue)
71 {
72    ir_variable *var;
73    ir_assignment *assign;
74    ir_rvalue *ir = *rvalue;
75 
76    if (!ir || !this->predicate(ir))
77       return;
78 
79    void *ctx = ralloc_parent(ir);
80 
81    var = new(ctx) ir_variable(ir->type, "flattening_tmp", ir_var_temporary);
82    base_ir->insert_before(var);
83 
84    assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(var),
85 				   ir,
86 				   NULL);
87    base_ir->insert_before(assign);
88 
89    *rvalue = new(ctx) ir_dereference_variable(var);
90 }
91