$NetBSD: patch-configure,v 1.4 2014/05/30 11:34:51 joerg Exp $

--- configure.orig	2014-05-28 20:18:38.000000000 +0000
+++ configure
@@ -78,14 +78,18 @@ build_config()
 		[ "$amd64" = "true" ] && echo "ARCH_X86_64=1" && echo "CFLAGS+=-DARCH_X86_64"
 		[ "$arch" != "" ] && echo "TARGETARCH=-march=$arch"
 		[ "$cpu" != "" ] && echo "TARGETCPU=-mcpu=$cpu"
-		if [ "$optimisations" = "true" ]
-		then
-			echo "OPTIMISATIONS=-O2 -pipe"
-			# Since gcc 4.6, this optimization enabled with -O1 causes filter_line_sse2 to crash.
-			echo "OPTIMISATIONS+=-fno-tree-dominator-opts"
-			# Since gcc 4.6, this optimization enabled with -O2 causes filter_line_sse2 to crash.
-			echo "OPTIMISATIONS+=-fno-tree-pre"
-		fi
+		case $(${CC} --version 2> /dev/null) in
+		gcc*)
+			if [ "$optimisations" = "true" ]
+			then
+				echo "OPTIMISATIONS=-O2 -pipe"
+				# Since gcc 4.6, this optimization enabled with -O1 causes filter_line_sse2 to crash.
+				echo "OPTIMISATIONS+=-fno-tree-dominator-opts"
+				# Since gcc 4.6, this optimization enabled with -O2 causes filter_line_sse2 to crash.
+				echo "OPTIMISATIONS+=-fno-tree-pre"
+			fi
+			;;
+		esac
 
 		echo "CFLAGS+=-Wall -DPIC \$(TARGETARCH) \$(TARGETCPU) \$(OPTIMISATIONS) \$(MMX_FLAGS) \$(SSE_FLAGS) \$(SSE2_FLAGS) \$(DEBUG_FLAGS) \$(LARGE_FILE)"