https://bugs.gentoo.org/849722
https://github.com/InBetweenNames/gentooLTO/issues/846
https://github.com/vaeth/portage-bashrc-mv/issues/11
--- a/gcc/gcc/configure
+++ b/gcc/gcc/configure
@@ -5389,7 +5388,0 @@
-# Remove the -O2: for historical reasons, unless bootstrapping we prefer
-# optimizations to be activated explicitly by the toplevel.
-case "$CC" in
-  */prev-gcc/xgcc*) ;;
-  *) CFLAGS=`echo "$CFLAGS " | sed -e "s/-Ofast[ 	]//" -e "s/-O[gs][ 	]//" -e "s/-O[0-9]*[ 	]//" `
-     CXXFLAGS=`echo "$CXXFLAGS " | sed -e "s/-Ofast[ 	]//" -e "s/-O[gs][ 	]//" -e "s/-O[0-9]*[ 	]//" ` ;;
-esac
--- a/gcc/gcc/configure.ac
+++ b/gcc/gcc/configure.ac
@@ -443,7 +442,0 @@
-# Remove the -O2: for historical reasons, unless bootstrapping we prefer
-# optimizations to be activated explicitly by the toplevel.
-case "$CC" in
-  */prev-gcc/xgcc*) ;;
-  *) CFLAGS=`echo "$CFLAGS " | sed -e "s/-Ofast[[ 	]]//" -e "s/-O[[gs]][[ 	]]//" -e "s/-O[[0-9]]*[[ 	]]//" `
-     CXXFLAGS=`echo "$CXXFLAGS " | sed -e "s/-Ofast[[ 	]]//" -e "s/-O[[gs]][[ 	]]//" -e "s/-O[[0-9]]*[[ 	]]//" ` ;;
-esac