1 files changed, 81 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/compiler/translator/UnfoldShortCircuitAST.cpp b/src/3rdparty/angle/src/compiler/translator/UnfoldShortCircuitAST.cpp
new file mode 100644
index 0000000000..29c4397d56
--- /dev/null
+++ b/src/3rdparty/angle/src/compiler/translator/UnfoldShortCircuitAST.cpp
@@ -0,0 +1,81 @@
+//
+// 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.
+//
+
+#include "compiler/translator/UnfoldShortCircuitAST.h"
+
+namespace
+{
+
+// "x || y" is equivalent to "x ? true : y".
+TIntermSelection *UnfoldOR(TIntermTyped *x, TIntermTyped *y)
+{
+    const TType boolType(EbtBool, EbpUndefined);
+    ConstantUnion *u = new ConstantUnion;
+    u->setBConst(true);
+    TIntermConstantUnion *trueNode = new TIntermConstantUnion(
+        u, TType(EbtBool, EbpUndefined, EvqConst, 1));
+    return new TIntermSelection(x, trueNode, y, boolType);
+}
+
+// "x && y" is equivalent to "x ? y : false".
+TIntermSelection *UnfoldAND(TIntermTyped *x, TIntermTyped *y)
+{
+    const TType boolType(EbtBool, EbpUndefined);
+    ConstantUnion *u = new ConstantUnion;
+    u->setBConst(false);
+    TIntermConstantUnion *falseNode = new TIntermConstantUnion(
+        u, TType(EbtBool, EbpUndefined, EvqConst, 1));
+    return new TIntermSelection(x, y, falseNode, boolType);
+}
+
+}  // namespace anonymous
+
+bool UnfoldShortCircuitAST::visitBinary(Visit visit, TIntermBinary *node)
+{
+    TIntermSelection *replacement = NULL;
+
+    switch (node->getOp())
+    {
+      case EOpLogicalOr:
+        replacement = UnfoldOR(node->getLeft(), node->getRight());
+        break;
+      case EOpLogicalAnd:
+        replacement = UnfoldAND(node->getLeft(), node->getRight());
+        break;
+      default:
+        break;
+    }
+    if (replacement)
+    {
+        replacements.push_back(
+            NodeUpdateEntry(getParentNode(), node, replacement));
+    }
+    return true;
+}
+
+void UnfoldShortCircuitAST::updateTree()
+{
+    for (size_t ii = 0; ii < replacements.size(); ++ii)
+    {
+        const NodeUpdateEntry& entry = replacements[ii];
+        ASSERT(entry.parent);
+        bool replaced = entry.parent->replaceChildNode(
+            entry.original, entry.replacement);
+        ASSERT(replaced);
+
+        // In AST traversing, a parent is visited before its children.
+        // After we replace a node, if an immediate child is to
+        // be replaced, we need to make sure we don't update the replaced
+	// node; instead, we update the replacement node.
+        for (size_t jj = ii + 1; jj < replacements.size(); ++jj)
+        {
+            NodeUpdateEntry& entry2 = replacements[jj];
+            if (entry2.parent == entry.original)
+                entry2.parent = entry.replacement;
+        }
+    }
+}
+