iwmmxt: Disallow if gcc version is < 4.8.

Later versions of gcc-4.7.x are capable of generating iwMMXt
instructions properly, but gcc-4.8 contains better support and other
fixes, including iwMMXt in conjunction with hardfp. The existing 4.5
requirement was based on attempts to have OLPC use a patched gcc to
build pixman. Let's just require gcc-4.8.

diff --git a/configure.ac b/configure.ac
index 5b9512c..daf4062 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -631,8 +631,8 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
 #ifndef __IWMMXT__
 #error "IWMMXT not enabled (with -march=iwmmxt)"
 #endif
-#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 5))
-#error "Need GCC >= 4.5 for IWMMXT intrinsics"
+#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8))
+#error "Need GCC >= 4.8 for IWMMXT intrinsics"
 #endif
 #include <mmintrin.h>
 int main () {