1 files changed, 83 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/compiler/translator/RemoveArrayLengthMethod.cpp b/src/3rdparty/angle/src/compiler/translator/RemoveArrayLengthMethod.cpp
new file mode 100644
index 0000000000..e9e6a17013
--- /dev/null
+++ b/src/3rdparty/angle/src/compiler/translator/RemoveArrayLengthMethod.cpp
@@ -0,0 +1,83 @@
+//
+// Copyright (c) 2017 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.
+//
+// RemoveArrayLengthMethod.cpp:
+//   Fold array length expressions, including cases where the "this" node has side effects.
+//   Example:
+//     int i = (a = b).length();
+//     int j = (func()).length();
+//   becomes:
+//     (a = b);
+//     int i = <constant array length>;
+//     func();
+//     int j = <constant array length>;
+//
+//   Must be run after SplitSequenceOperator, SimplifyLoopConditions and SeparateDeclarations steps
+//   have been done to expressions containing calls of the array length method.
+//
+//   Does nothing to length method calls done on runtime-sized arrays.
+
+#include "compiler/translator/RemoveArrayLengthMethod.h"
+
+#include "compiler/translator/IntermNode.h"
+#include "compiler/translator/IntermTraverse.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class RemoveArrayLengthTraverser : public TIntermTraverser
+{
+  public:
+    RemoveArrayLengthTraverser() : TIntermTraverser(true, false, false), mFoundArrayLength(false) {}
+
+    bool visitUnary(Visit visit, TIntermUnary *node) override;
+
+    void nextIteration() { mFoundArrayLength = false; }
+
+    bool foundArrayLength() const { return mFoundArrayLength; }
+
+  private:
+    bool mFoundArrayLength;
+};
+
+bool RemoveArrayLengthTraverser::visitUnary(Visit visit, TIntermUnary *node)
+{
+    // The only case where we leave array length() in place is for runtime-sized arrays.
+    if (node->getOp() == EOpArrayLength && !node->getOperand()->getType().isUnsizedArray())
+    {
+        mFoundArrayLength = true;
+        if (!node->getOperand()->hasSideEffects())
+        {
+            queueReplacement(node->fold(nullptr), OriginalNode::IS_DROPPED);
+            return false;
+        }
+        insertStatementInParentBlock(node->getOperand()->deepCopy());
+        TConstantUnion *constArray = new TConstantUnion[1];
+        constArray->setIConst(node->getOperand()->getOutermostArraySize());
+        queueReplacement(new TIntermConstantUnion(constArray, node->getType()),
+                         OriginalNode::IS_DROPPED);
+        return false;
+    }
+    return true;
+}
+
+}  // anonymous namespace
+
+void RemoveArrayLengthMethod(TIntermBlock *root)
+{
+    RemoveArrayLengthTraverser traverser;
+    do
+    {
+        traverser.nextIteration();
+        root->traverse(&traverser);
+        if (traverser.foundArrayLength())
+            traverser.updateTree();
+    } while (traverser.foundArrayLength());
+}
+
+}  // namespace sh