1 files changed, 117 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/RewriteUnaryMinusOperatorInt.cpp b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/RewriteUnaryMinusOperatorInt.cpp
new file mode 100644
index 0000000000..5d8cdb657d
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/RewriteUnaryMinusOperatorInt.cpp
@@ -0,0 +1,117 @@
+//
+// 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.
+//
+// Implementation of evaluating unary integer variable bug workaround.
+// See header for more info.
+
+#include "compiler/translator/tree_ops/d3d/RewriteUnaryMinusOperatorInt.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;
+    }
+
+    // Decide if the current unary operator is unary minus.
+    if (node->getOp() != EOpNegative)
+    {
+        return true;
+    }
+
+    // Decide if the current operand is an integer variable.
+    TIntermTyped *opr = node->getOperand();
+    if (!opr->getType().isScalarInt())
+    {
+        return true;
+    }
+
+    // Potential problem case detected, apply workaround: -(int) -> ~(int) + 1.
+    // ~(int)
+    TIntermUnary *bitwiseNot = new TIntermUnary(EOpBitwiseNot, opr, nullptr);
+    bitwiseNot->setLine(opr->getLine());
+
+    // Constant 1 (or 1u)
+    TConstantUnion *one = new TConstantUnion();
+    if (opr->getType().getBasicType() == EbtInt)
+    {
+        one->setIConst(1);
+    }
+    else
+    {
+        one->setUConst(1u);
+    }
+    TType *oneType = new TType(opr->getType());
+    oneType->setQualifier(EvqConst);
+
+    TIntermConstantUnion *oneNode = new TIntermConstantUnion(one, *oneType);
+    oneNode->setLine(opr->getLine());
+
+    // ~(int) + 1
+    TIntermBinary *add = new TIntermBinary(EOpAdd, bitwiseNot, oneNode);
+    add->setLine(opr->getLine());
+
+    queueReplacement(add, OriginalNode::IS_DROPPED);
+
+    mFound = true;
+    return false;
+}
+
+}  // anonymous namespace
+
+bool RewriteUnaryMinusOperatorInt(TCompiler *compiler, TIntermNode *root)
+{
+    return Traverser::Apply(compiler, root);
+}
+
+}  // namespace sh