D3D: Work around HLSL integer pow folding bug.
BUG=angleproject:851
Change-Id: I68a47b8343a29e42c0a69ca3f2a6cb5054d03782
Reviewed-on: https://chromium-review.googlesource.com/362775
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/ExpandIntegerPowExpressions.h b/src/compiler/translator/ExpandIntegerPowExpressions.h
new file mode 100644
index 0000000..8bc8c96
--- /dev/null
+++ b/src/compiler/translator/ExpandIntegerPowExpressions.h
@@ -0,0 +1,28 @@
+//
+// Copyright (c) 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.
+//
+// This mutating tree traversal works around a bug in the HLSL compiler optimizer with "pow" that
+// manifests under the following conditions:
+//
+// - If pow() has a literal exponent value
+// - ... and this value is integer or within 10e-6 of an integer
+// - ... and it is in {-4, -3, -2, 2, 3, 4, 5, 6, 7, 8}
+//
+// The workaround is to replace the pow with a series of multiplies.
+// See http://anglebug.com/851
+
+#ifndef COMPILER_TRANSLATOR_EXPANDINTEGERPOWEXPRESSIONS_H_
+#define COMPILER_TRANSLATOR_EXPANDINTEGERPOWEXPRESSIONS_H_
+
+class TIntermNode;
+
+namespace sh
+{
+
+void ExpandIntegerPowExpressions(TIntermNode *root, unsigned int *tempIndex);
+
+} // namespace sh
+
+#endif // COMPILER_TRANSLATOR_EXPANDINTEGERPOWEXPRESSIONS_H_