work around ICE in gcc 4.4.x

configure.ac

@@ -53,19 +53,16 @@ case $CCTYPE in
     GCCVERSION="`$CC -dumpversion 2>&1`"
     echo "Using gcc version $GCCVERSION"
     AC_SUBST(GCCVERSION)
-    case $system in
-      Darwin-*)
-        ;;
-      *)
-        CCFLAGS="$CCFLAGS -ffunction-sections -fdata-sections"
-        ;;
-    esac
     changequote(,)
-    gcc43=`echo $GCCVERSION | grep -c '4\.[3456789]'`
+    gcc43=`echo $GCCVERSION | grep -c '^4\.[3456789]'`
+    gcc44=`echo $GCCVERSION | grep -c '^4\.4'`
     changequote([,])
     if test $gcc43 -gt 0; then
       CCFLAGS="$CCFLAGS -march=native"
     fi
+    if test $gcc44 -gt 0; then
+      CCFLAGS="$CCFLAGS -fno-tree-fre"
+    fi
     ;;
   icc)
     CCFLAGS="-O3 -xHOST -std=c99 -ip -Wbrief -Wall -vec-report0 -openmp-report0 -wd383,981,1419,1572"