Fix the build on GCC 4.x after 812e8f2a1

The ancient GCC 4.x doesn't understand the "optimize" attribute until 4.4.
Fix the build on platforms with GCC 4.x < 4.4 by limiting the DONT_VECTORIZE
definition to GCC 5 and greater.

Noticed and patch proposed by Warner Losh <imp@FreeBSD.org>.

diff --git a/lib/common/compiler.h b/lib/common/compiler.h
index 87bf51ae8c896c1af9411d214a2e2c9a9e04f07a..d18179582259a36a9774f0eae6194d400d2c7edc 100644 (file)
--- a/lib/common/compiler.h
+++ b/lib/common/compiler.h
@@ -128,7 +128,7 @@
 }
 
 /* vectorization */
-#if !defined(__clang__) && defined(__GNUC__)
+#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 5
 #  define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
 #else
 #  define DONT_VECTORIZE