build: fix build with -mno-ssse3

Avoid the following error with -mno-ssse3:
 inlining failed in call to 'always_inline' '_mm_shuffle_epi8':
 target specific option mismatch

* configure.ac: Ensure we use ssse3 specific code when
checking whether to enable the pclmul cksum implementation.

diff --git a/configure.ac b/configure.ac
index 2b2f9468d5d8a777ac338729886523249ae1c738..664d25ec6a089a6d6c760f5083cb401a47f33d81 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -578,6 +578,7 @@ AC_COMPILE_IFELSE(
     {
       __m128i a, b;
       a = _mm_clmulepi64_si128 (a, b, 0x00);
+      a = _mm_shuffle_epi8 (a, b);
       return 1;
     }
   ]])