1 files changed, 97 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_ops/apple/RewriteUnaryMinusOperatorFloat.cpp b/gfx/angle/checkout/src/compiler/translator/tree_ops/apple/RewriteUnaryMinusOperatorFloat.cpp
new file mode 100644
index 0000000000..4aa8a28203
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_ops/apple/RewriteUnaryMinusOperatorFloat.cpp
@@ -0,0 +1,97 @@
+//
+// Copyright 2016 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/tree_ops/apple/RewriteUnaryMinusOperatorFloat.h"
+
+#include "compiler/translator/tree_util/IntermNode_util.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class Traverser : public TIntermTraverser
+{
+  public:
+    [[nodiscard]] static bool Apply(TCompiler *compiler, TIntermNode *root);
+
+  private:
+    Traverser();
+    bool visitUnary(Visit visit, TIntermUnary *node) override;
+    void nextIteration();
+
+    bool mFound = false;
+};
+
+// static
+bool Traverser::Apply(TCompiler *compiler, TIntermNode *root)
+{
+    Traverser traverser;
+    do
+    {
+        traverser.nextIteration();
+        root->traverse(&traverser);
+        if (traverser.mFound)
+        {
+            if (!traverser.updateTree(compiler, root))
+            {
+                return false;
+            }
+        }
+    } while (traverser.mFound);
+
+    return true;
+}
+
+Traverser::Traverser() : TIntermTraverser(true, false, false) {}
+
+void Traverser::nextIteration()
+{
+    mFound = false;
+}
+
+bool Traverser::visitUnary(Visit visit, TIntermUnary *node)
+{
+    if (mFound)
+    {
+        return false;
+    }
+
+    // Detect if the current operator is unary minus operator.
+    if (node->getOp() != EOpNegative)
+    {
+        return true;
+    }
+
+    // Detect if the current operand is a float variable.
+    TIntermTyped *fValue = node->getOperand();
+    if (!fValue->getType().isScalarFloat())
+    {
+        return true;
+    }
+
+    // 0.0 - float
+    TIntermTyped *zero = CreateZeroNode(fValue->getType());
+    zero->setLine(fValue->getLine());
+    TIntermBinary *sub = new TIntermBinary(EOpSub, zero, fValue);
+    sub->setLine(fValue->getLine());
+
+    queueReplacement(sub, OriginalNode::IS_DROPPED);
+
+    mFound = true;
+    return false;
+}
+
+}  // anonymous namespace
+
+bool RewriteUnaryMinusOperatorFloat(TCompiler *compiler, TIntermNode *root)
+{
+    return Traverser::Apply(compiler, root);
+}
+
+}  // namespace sh