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 282873)
+++ source/libvpx/test/register_state_check.h	(working copy)
@@ -13,7 +13,21 @@
 
 #include "third_party/googletest/src/include/gtest/gtest.h"
 #include "./vpx_config.h"
+#include "vpx/vpx_integer.h"
 
+// ASM_REGISTER_STATE_CHECK(asm_function)
+//   Minimally validates the environment pre & post function execution. This
+//   variant should be used with assembly functions which are not expected to
+//   fully restore the system state. See platform implementations of
+//   RegisterStateCheck for details.
+//
+// API_REGISTER_STATE_CHECK(api_function)
+//   Performs all the checks done by ASM_REGISTER_STATE_CHECK() and any
+//   additional checks to ensure the environment is in a consistent state pre &
+//   post function execution. This variant should be used with API functions.
+//   See platform implementations of RegisterStateCheckXXX for details.
+//
+
 #if defined(_WIN64)
 
 #define _WIN32_LEAN_AND_MEAN
@@ -35,11 +49,6 @@
 // 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_); }
@@ -75,9 +84,9 @@
   CONTEXT pre_context_;
 };
 
-#define REGISTER_STATE_CHECK(statement) do { \
-  libvpx_test::RegisterStateCheck reg_check; \
-  statement;                               \
+#define ASM_REGISTER_STATE_CHECK(statement) do {  \
+  libvpx_test::RegisterStateCheck reg_check;      \
+  statement;                                      \
 } while (false)
 
 }  // namespace libvpx_test
@@ -85,8 +94,6 @@
 #elif defined(CONFIG_SHARED) && defined(HAVE_NEON_ASM) && defined(CONFIG_VP9) \
       && !CONFIG_SHARED && HAVE_NEON_ASM && CONFIG_VP9
 
-#include "vpx/vpx_integer.h"
-
 extern "C" {
 // Save the d8-d15 registers into store.
 void vp9_push_neon(int64_t *store);
@@ -97,11 +104,6 @@
 // Compares the state of d8-d15 at construction with their state at
 // destruction. These registers should be preserved by the callee on
 // arm platform.
-// Usage:
-// {
-//   RegisterStateCheck reg_check;
-//   FunctionToVerify();
-// }
 class RegisterStateCheck {
  public:
   RegisterStateCheck() { initialized_ = StoreRegisters(pre_store_); }
@@ -129,9 +131,9 @@
   int64_t pre_store_[8];
 };
 
-#define REGISTER_STATE_CHECK(statement) do { \
-  libvpx_test::RegisterStateCheck reg_check; \
-  statement;                               \
+#define ASM_REGISTER_STATE_CHECK(statement) do {  \
+  libvpx_test::RegisterStateCheck reg_check;      \
+  statement;                                      \
 } while (false)
 
 }  // namespace libvpx_test
@@ -141,10 +143,54 @@
 namespace libvpx_test {
 
 class RegisterStateCheck {};
-#define REGISTER_STATE_CHECK(statement) statement
+#define ASM_REGISTER_STATE_CHECK(statement) statement
 
 }  // namespace libvpx_test
 
 #endif  // _WIN64
 
+#if ARCH_X86 || ARCH_X86_64
+#if defined(__GNUC__)
+
+namespace libvpx_test {
+
+// Checks the FPU tag word pre/post execution to ensure emms has been called.
+class RegisterStateCheckMMX {
+ public:
+  RegisterStateCheckMMX() {
+    __asm__ volatile("fstenv %0" : "=rm"(pre_fpu_env_));
+  }
+  ~RegisterStateCheckMMX() { EXPECT_TRUE(Check()); }
+
+ private:
+  // Checks the FPU tag word pre/post execution, returning false if not cleared
+  // to 0xffff.
+  bool Check() const {
+    EXPECT_EQ(0xffff, pre_fpu_env_[4])
+        << "FPU was in an inconsistent state prior to call";
+
+    uint16_t post_fpu_env[14];
+    __asm__ volatile("fstenv %0" : "=rm"(post_fpu_env));
+    EXPECT_EQ(0xffff, post_fpu_env[4])
+        << "FPU was left in an inconsistent state after call";
+    return !testing::Test::HasNonfatalFailure();
+  }
+
+  uint16_t pre_fpu_env_[14];
+};
+
+#define API_REGISTER_STATE_CHECK(statement) do {  \
+  libvpx_test::RegisterStateCheckMMX reg_check;   \
+  ASM_REGISTER_STATE_CHECK(statement);            \
+} while (false)
+
+}  // namespace libvpx_test
+
+#endif  // __GNUC__
+#endif  // ARCH_X86 || ARCH_X86_64
+
+#ifndef API_REGISTER_STATE_CHECK
+#define API_REGISTER_STATE_CHECK ASM_REGISTER_STATE_CHECK
+#endif
+
 #endif  // TEST_REGISTER_STATE_CHECK_H_