Runtime CPU detection for unit tests

Filter out tests that require SIMD extensions if the host doesn't
support them.

Change-Id: Ifac4b73e98e64f9f1b082cc0ffbf5c2faffb0834

test/test_libvpx.cc

@@ -7,8 +7,38 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+#include <string>
+#include "vpx_config.h"
+#if ARCH_X86 || ARCH_X86_64
+#include "vpx_ports/x86.h"
+#endif
 #include "third_party/googletest/src/include/gtest/gtest.h"
+
+static void append_gtest_filter(const char *str)
+{
+  std::string filter = ::testing::FLAGS_gtest_filter;
+  filter += str;
+  ::testing::FLAGS_gtest_filter = filter;
+}
+
 int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);
+
+#if ARCH_X86 || ARCH_X86_64
+  int simd_caps = x86_simd_caps();
+  if(!(simd_caps & HAS_MMX))
+    append_gtest_filter(":-MMX/*");
+  if(!(simd_caps & HAS_SSE))
+    append_gtest_filter(":-SSE/*");
+  if(!(simd_caps & HAS_SSE2))
+    append_gtest_filter(":-SSE2/*");
+  if(!(simd_caps & HAS_SSE3))
+    append_gtest_filter(":-SSE3/*");
+  if(!(simd_caps & HAS_SSSE3))
+    append_gtest_filter(":-SSSE3/*");
+  if(!(simd_caps & HAS_SSE4_1))
+    append_gtest_filter(":-SSE4_1/*");
+#endif
+
   return RUN_ALL_TESTS();
 }