libvpx: Pull from upstream

source/libvpx/test/register_state_check.h

Index: source/libvpx/test/register_state_check.h
===================================================================
--- source/libvpx/test/register_state_check.h	(revision 0)
+++ source/libvpx/test/register_state_check.h	(revision 0)
@@ -0,0 +1,95 @@
+/*
+ *  Copyright (c) 2012 The WebM 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 in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef LIBVPX_TEST_REGISTER_STATE_CHECK_H_
+#define LIBVPX_TEST_REGISTER_STATE_CHECK_H_
+
+#ifdef _WIN64
+
+#define _WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <winnt.h>
+
+#include "third_party/googletest/src/include/gtest/gtest.h"
+
+namespace testing {
+namespace internal {
+
+inline bool operator==(const M128A& lhs, const M128A& rhs) {
+  return (lhs.Low == rhs.Low && lhs.High == rhs.High);
+}
+
+}  // namespace internal
+}  // namespace testing
+
+namespace libvpx_test {
+
+// Compares the state of xmm[6-15] at construction with their state at
+// destruction. These registers should be preserved by the callee on
+// Windows x64.
+// Usage:
+// {
+//   RegisterStateCheck reg_check;
+//   FunctionToVerify();
+// }
+class RegisterStateCheck {
+ public:
+  RegisterStateCheck() { initialized_ = StoreRegisters(&pre_context_); }
+  ~RegisterStateCheck() { EXPECT_TRUE(Check()); }
+
+ private:
+  static bool StoreRegisters(CONTEXT* const context) {
+    const HANDLE this_thread = GetCurrentThread();
+    EXPECT_TRUE(this_thread != NULL);
+    context->ContextFlags = CONTEXT_FLOATING_POINT;
+    const bool context_saved = GetThreadContext(this_thread, context) == TRUE;
+    EXPECT_TRUE(context_saved) << "GetLastError: " << GetLastError();
+    return context_saved;
+  }
+
+  // Compares the register state. Returns true if the states match.
+  bool Check() const {
+    if (!initialized_) return false;
+    CONTEXT post_context;
+    if (!StoreRegisters(&post_context)) return false;
+
+    const M128A* xmm_pre = &pre_context_.Xmm6;
+    const M128A* xmm_post = &post_context.Xmm6;
+    for (int i = 6; i <= 15; ++i) {
+      EXPECT_EQ(*xmm_pre, *xmm_post) << "xmm" << i << " has been modified!";
+      ++xmm_pre;
+      ++xmm_post;
+    }
+    return !testing::Test::HasNonfatalFailure();
+  }
+
+  bool initialized_;
+  CONTEXT pre_context_;
+};
+
+#define REGISTER_STATE_CHECK(statement) do { \
+  libvpx_test::RegisterStateCheck reg_check; \
+  statement;                               \
+} while (false)
+
+}  // namespace libvpx_test
+
+#else  // !_WIN64
+
+namespace libvpx_test {
+
+class RegisterStateCheck {};
+#define REGISTER_STATE_CHECK(statement) statement
+
+}  // namespace libvpx_test
+
+#endif  // _WIN64
+
+#endif  // LIBVPX_TEST_REGISTER_STATE_CHECK_H_