Revision 3a55fb0d9fe8e2f4594329edd58c5fd6f35a99dd authored by Kirill Smelkov on 02 November 2012, 11:41:01 UTC, committed by Linus Torvalds on 16 January 2013, 20:42:57 UTC
In commit 281dc5c5ec0f ("Give up on pushing CC_OPTIMIZE_FOR_SIZE") we
already changed the actual default value, but the help-text still
suggested 'y'. Fix the help text too, for all the same reasons.
Sadly, -Os keeps on generating some very suboptimal code for certain
cases, to the point where any I$ miss upside is swamped by the downside.
The main ones are:
- using "rep movsb" for memcpy, even on CPU's where that is
horrendously bad for performance.
- not honoring branch prediction information, so any I$ footprint you
win from smaller code, you lose from less code density in the I$.
- using divide instructions when that is very expensive.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent fbfc23e
.gitignore
#
# Generated files
#
gen_init_cpio
initramfs_data.cpio
initramfs_data.cpio.gz
initramfs_data.cpio.bz2
initramfs_data.cpio.lzma
initramfs_list
include
Computing file changes ...
