blob: 47f0afca6a6fc133e74f755bdf80ee9812e62d16 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
//
// Copyright (c) 2002-2013 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// UnfoldShortCircuit is an AST traverser to output short-circuiting operators as if-else statements.
// The results are assigned to s# temporaries, which are used by the main translator instead of
// the original expression.
//
#include "compiler/UnfoldShortCircuit.h"
#include "compiler/InfoSink.h"
#include "compiler/OutputHLSL.h"
namespace sh
{
UnfoldShortCircuit::UnfoldShortCircuit(TParseContext &context, OutputHLSL *outputHLSL) : mContext(context), mOutputHLSL(outputHLSL)
{
mTemporaryIndex = 0;
}
void UnfoldShortCircuit::traverse(TIntermNode *node)
{
int rewindIndex = mTemporaryIndex;
node->traverse(this);
mTemporaryIndex = rewindIndex;
}
bool UnfoldShortCircuit::visitBinary(Visit visit, TIntermBinary *node)
{
TInfoSinkBase &out = mOutputHLSL->getBodyStream();
switch (node->getOp())
{
case EOpLogicalOr:
// "x || y" is equivalent to "x ? true : y", which unfolds to "bool s; if(x) s = true; else s = y;",
// and then further simplifies down to "bool s = x; if(!s) s = y;".
{
int i = mTemporaryIndex;
out << "bool s" << i << ";\n";
out << "{\n";
mTemporaryIndex = i + 1;
node->getLeft()->traverse(this);
out << "s" << i << " = ";
mTemporaryIndex = i + 1;
node->getLeft()->traverse(mOutputHLSL);
out << ";\n";
out << "if(!s" << i << ")\n"
"{\n";
mTemporaryIndex = i + 1;
node->getRight()->traverse(this);
out << " s" << i << " = ";
mTemporaryIndex = i + 1;
node->getRight()->traverse(mOutputHLSL);
out << ";\n"
"}\n";
out << "}\n";
mTemporaryIndex = i + 1;
}
return false;
case EOpLogicalAnd:
// "x && y" is equivalent to "x ? y : false", which unfolds to "bool s; if(x) s = y; else s = false;",
// and then further simplifies down to "bool s = x; if(s) s = y;".
{
int i = mTemporaryIndex;
out << "bool s" << i << ";\n";
out << "{\n";
mTemporaryIndex = i + 1;
node->getLeft()->traverse(this);
out << "s" << i << " = ";
mTemporaryIndex = i + 1;
node->getLeft()->traverse(mOutputHLSL);
out << ";\n";
out << "if(s" << i << ")\n"
"{\n";
mTemporaryIndex = i + 1;
node->getRight()->traverse(this);
out << " s" << i << " = ";
mTemporaryIndex = i + 1;
node->getRight()->traverse(mOutputHLSL);
out << ";\n"
"}\n";
out << "}\n";
mTemporaryIndex = i + 1;
}
return false;
default:
return true;
}
}
bool UnfoldShortCircuit::visitSelection(Visit visit, TIntermSelection *node)
{
TInfoSinkBase &out = mOutputHLSL->getBodyStream();
// Unfold "b ? x : y" into "type s; if(b) s = x; else s = y;"
if (node->usesTernaryOperator())
{
int i = mTemporaryIndex;
out << mOutputHLSL->typeString(node->getType()) << " s" << i << ";\n";
out << "{\n";
mTemporaryIndex = i + 1;
node->getCondition()->traverse(this);
out << "if(";
mTemporaryIndex = i + 1;
node->getCondition()->traverse(mOutputHLSL);
out << ")\n"
"{\n";
mTemporaryIndex = i + 1;
node->getTrueBlock()->traverse(this);
out << " s" << i << " = ";
mTemporaryIndex = i + 1;
node->getTrueBlock()->traverse(mOutputHLSL);
out << ";\n"
"}\n"
"else\n"
"{\n";
mTemporaryIndex = i + 1;
node->getFalseBlock()->traverse(this);
out << " s" << i << " = ";
mTemporaryIndex = i + 1;
node->getFalseBlock()->traverse(mOutputHLSL);
out << ";\n"
"}\n";
out << "}\n";
mTemporaryIndex = i + 1;
}
return false;
}
bool UnfoldShortCircuit::visitLoop(Visit visit, TIntermLoop *node)
{
int rewindIndex = mTemporaryIndex;
if (node->getInit())
{
node->getInit()->traverse(this);
}
if (node->getCondition())
{
node->getCondition()->traverse(this);
}
if (node->getExpression())
{
node->getExpression()->traverse(this);
}
mTemporaryIndex = rewindIndex;
return false;
}
int UnfoldShortCircuit::getNextTemporaryIndex()
{
return mTemporaryIndex++;
}
}
|
