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comparison: gfx/angle/src/compiler/UnfoldShortCircuit.cpp
gfx/angle/src/compiler/UnfoldShortCircuit.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:3ae062bb5558 |
|---|---|
| 1 // | |
| 2 // Copyright (c) 2002-2013 The ANGLE Project Authors. All rights reserved. | |
| 3 // Use of this source code is governed by a BSD-style license that can be | |
| 4 // found in the LICENSE file. | |
| 5 // | |
| 6 // UnfoldShortCircuit is an AST traverser to output short-circuiting operators as if-else statements. | |
| 7 // The results are assigned to s# temporaries, which are used by the main translator instead of | |
| 8 // the original expression. | |
| 9 // | |
| 10 | |
| 11 #include "compiler/UnfoldShortCircuit.h" | |
| 12 | |
| 13 #include "compiler/InfoSink.h" | |
| 14 #include "compiler/OutputHLSL.h" | |
| 15 | |
| 16 namespace sh | |
| 17 { | |
| 18 UnfoldShortCircuit::UnfoldShortCircuit(TParseContext &context, OutputHLSL *outputHLSL) : mContext(context), mOutputHLSL(outputHLSL) | |
| 19 { | |
| 20 mTemporaryIndex = 0; | |
| 21 } | |
| 22 | |
| 23 void UnfoldShortCircuit::traverse(TIntermNode *node) | |
| 24 { | |
| 25 int rewindIndex = mTemporaryIndex; | |
| 26 node->traverse(this); | |
| 27 mTemporaryIndex = rewindIndex; | |
| 28 } | |
| 29 | |
| 30 bool UnfoldShortCircuit::visitBinary(Visit visit, TIntermBinary *node) | |
| 31 { | |
| 32 TInfoSinkBase &out = mOutputHLSL->getBodyStream(); | |
| 33 | |
| 34 switch (node->getOp()) | |
| 35 { | |
| 36 case EOpLogicalOr: | |
| 37 // "x || y" is equivalent to "x ? true : y", which unfolds to "bool s; if(x) s = true; else s = y;", | |
| 38 // and then further simplifies down to "bool s = x; if(!s) s = y;". | |
| 39 { | |
| 40 int i = mTemporaryIndex; | |
| 41 | |
| 42 out << "bool s" << i << ";\n"; | |
| 43 | |
| 44 out << "{\n"; | |
| 45 | |
| 46 mTemporaryIndex = i + 1; | |
| 47 node->getLeft()->traverse(this); | |
| 48 out << "s" << i << " = "; | |
| 49 mTemporaryIndex = i + 1; | |
| 50 node->getLeft()->traverse(mOutputHLSL); | |
| 51 out << ";\n"; | |
| 52 out << "if(!s" << i << ")\n" | |
| 53 "{\n"; | |
| 54 mTemporaryIndex = i + 1; | |
| 55 node->getRight()->traverse(this); | |
| 56 out << " s" << i << " = "; | |
| 57 mTemporaryIndex = i + 1; | |
| 58 node->getRight()->traverse(mOutputHLSL); | |
| 59 out << ";\n" | |
| 60 "}\n"; | |
| 61 | |
| 62 out << "}\n"; | |
| 63 | |
| 64 mTemporaryIndex = i + 1; | |
| 65 } | |
| 66 return false; | |
| 67 case EOpLogicalAnd: | |
| 68 // "x && y" is equivalent to "x ? y : false", which unfolds to "bool s; if(x) s = y; else s = false;", | |
| 69 // and then further simplifies down to "bool s = x; if(s) s = y;". | |
| 70 { | |
| 71 int i = mTemporaryIndex; | |
| 72 | |
| 73 out << "bool s" << i << ";\n"; | |
| 74 | |
| 75 out << "{\n"; | |
| 76 | |
| 77 mTemporaryIndex = i + 1; | |
| 78 node->getLeft()->traverse(this); | |
| 79 out << "s" << i << " = "; | |
| 80 mTemporaryIndex = i + 1; | |
| 81 node->getLeft()->traverse(mOutputHLSL); | |
| 82 out << ";\n"; | |
| 83 out << "if(s" << i << ")\n" | |
| 84 "{\n"; | |
| 85 mTemporaryIndex = i + 1; | |
| 86 node->getRight()->traverse(this); | |
| 87 out << " s" << i << " = "; | |
| 88 mTemporaryIndex = i + 1; | |
| 89 node->getRight()->traverse(mOutputHLSL); | |
| 90 out << ";\n" | |
| 91 "}\n"; | |
| 92 | |
| 93 out << "}\n"; | |
| 94 | |
| 95 mTemporaryIndex = i + 1; | |
| 96 } | |
| 97 return false; | |
| 98 default: | |
| 99 return true; | |
| 100 } | |
| 101 } | |
| 102 | |
| 103 bool UnfoldShortCircuit::visitSelection(Visit visit, TIntermSelection *node) | |
| 104 { | |
| 105 TInfoSinkBase &out = mOutputHLSL->getBodyStream(); | |
| 106 | |
| 107 // Unfold "b ? x : y" into "type s; if(b) s = x; else s = y;" | |
| 108 if (node->usesTernaryOperator()) | |
| 109 { | |
| 110 int i = mTemporaryIndex; | |
| 111 | |
| 112 out << mOutputHLSL->typeString(node->getType()) << " s" << i << ";\n"; | |
| 113 | |
| 114 out << "{\n"; | |
| 115 | |
| 116 mTemporaryIndex = i + 1; | |
| 117 node->getCondition()->traverse(this); | |
| 118 out << "if("; | |
| 119 mTemporaryIndex = i + 1; | |
| 120 node->getCondition()->traverse(mOutputHLSL); | |
| 121 out << ")\n" | |
| 122 "{\n"; | |
| 123 mTemporaryIndex = i + 1; | |
| 124 node->getTrueBlock()->traverse(this); | |
| 125 out << " s" << i << " = "; | |
| 126 mTemporaryIndex = i + 1; | |
| 127 node->getTrueBlock()->traverse(mOutputHLSL); | |
| 128 out << ";\n" | |
| 129 "}\n" | |
| 130 "else\n" | |
| 131 "{\n"; | |
| 132 mTemporaryIndex = i + 1; | |
| 133 node->getFalseBlock()->traverse(this); | |
| 134 out << " s" << i << " = "; | |
| 135 mTemporaryIndex = i + 1; | |
| 136 node->getFalseBlock()->traverse(mOutputHLSL); | |
| 137 out << ";\n" | |
| 138 "}\n"; | |
| 139 | |
| 140 out << "}\n"; | |
| 141 | |
| 142 mTemporaryIndex = i + 1; | |
| 143 } | |
| 144 | |
| 145 return false; | |
| 146 } | |
| 147 | |
| 148 bool UnfoldShortCircuit::visitLoop(Visit visit, TIntermLoop *node) | |
| 149 { | |
| 150 int rewindIndex = mTemporaryIndex; | |
| 151 | |
| 152 if (node->getInit()) | |
| 153 { | |
| 154 node->getInit()->traverse(this); | |
| 155 } | |
| 156 | |
| 157 if (node->getCondition()) | |
| 158 { | |
| 159 node->getCondition()->traverse(this); | |
| 160 } | |
| 161 | |
| 162 if (node->getExpression()) | |
| 163 { | |
| 164 node->getExpression()->traverse(this); | |
| 165 } | |
| 166 | |
| 167 mTemporaryIndex = rewindIndex; | |
| 168 | |
| 169 return false; | |
| 170 } | |
| 171 | |
| 172 int UnfoldShortCircuit::getNextTemporaryIndex() | |
| 173 { | |
| 174 return mTemporaryIndex++; | |
| 175 } | |
| 176 } |
