diff options
Diffstat (limited to 'src/3rdparty/angle/src/compiler/UnfoldShortCircuit.cpp')
-rw-r--r-- | src/3rdparty/angle/src/compiler/UnfoldShortCircuit.cpp | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/compiler/UnfoldShortCircuit.cpp b/src/3rdparty/angle/src/compiler/UnfoldShortCircuit.cpp new file mode 100644 index 0000000000..1782ebc90c --- /dev/null +++ b/src/3rdparty/angle/src/compiler/UnfoldShortCircuit.cpp @@ -0,0 +1,172 @@ +// +// Copyright (c) 2002-2012 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; + } + + 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"; + + 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"; + + 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++; +} +} |