Hello,
as mentioned here
https://bugs.gentoo.org/show_bug.cgi?id=433497
there are unrecognized command line options when building aufs3 on PPC:
make -j2 CC=powerpc-unknown-linux-gnu-gcc CONFIG_AUFS_FS=m KDIR=/usr/src/linux
-I/var/tmp/portage/sys-fs/aufs3-3_p20120813/work/aufs3-standalone/include -DCONFIG_AUFS_FS_MODULE -UCONFIG_AUFS -DCONFIG_AUFS_BRANCH_MAX_127 -DCONFIG_AUFS_SBILIST -DCONFIG_AUFS_RDU
make -C /usr/src/linux M=/var/tmp/portage/sys-fs/aufs3-3_p20120813/work/aufs3-standalone/fs/aufs EXTRA_CFLAGS="-I/var/tmp/portage/sys-fs/aufs3-3_p20120813/work/aufs3-standalone/include -DCONFIG_AUFS_FS_MODULE -UCONFIG_AUFS -DCONFIG_AUFS_BRANCH_MAX_127 -DCONFIG_AUFS_SBILIST -DCONFIG_AUFS_RDU" modules
make[1]: Entering directory `/usr/src/linux-3.2.1-gentoo-r2'
CC [M] /var/tmp/portage/sys-fs/aufs3-3_p20120813/work/aufs3-standalone/fs/aufs/module.o
CC [M] /var/tmp/portage/sys-fs/aufs3-3_p20120813/work/aufs3-standalone/fs/aufs/sbinfo.o
cc1: error: unrecognized command line option ‘-mno-red-zone’
cc1: error: invalid option for -mcmodel: 'kernel'
cc1: error: unrecognized command line option ‘-mcmodel=kernel’
cc1: error: unrecognized command line option ‘-maccumulate-outgoing-args’
cc1: error: unrecognized command line option ‘-mno-red-zone’
cc1: error: invalid option for -mcmodel: 'kernel'
cc1: error: unrecognized command line option ‘-mcmodel=kernel’
cc1: error: unrecognized command line option ‘-maccumulate-outgoing-args’