Add configure-time checking for the SSE and AVX features on Windows

Modify configure.exe to run some configure-time tests and check if
the SSE and AVX compiler features are supported.

The tests themselves required a bit of changes to compile with
MSVC. The include in sse4_2.cpp was wrong. And for whatever reason, it
didn't like the volatile variables, which GCC, Clang and ICC have been
happy with. This should produce no effect in compilation, though: even
dead code must be syntactically correct. We're not running the output.

Change-Id: Ibe5d0904a378a7efed853c7215f88a2ddcefb1b3
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/config.tests/common/avx/avx.cpp b/config.tests/common/avx/avx.cpp
index bc5be65e65..9d849a79db 100644
--- a/config.tests/common/avx/avx.cpp
+++ b/config.tests/common/avx/avx.cpp
@@ -43,9 +43,9 @@
 
 int main(int, char**)
 {
-    volatile __m256d a = _mm256_setzero_pd();
-    volatile __m256d b = _mm256_set1_pd(42.42);
-    volatile __m256d result = _mm256_add_pd(a, b);
+    __m256d a = _mm256_setzero_pd();
+    __m256d b = _mm256_set1_pd(42.42);
+    __m256d result = _mm256_add_pd(a, b);
     (void)result;
     return 0;
 }