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
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .gitignore | -rw-r--r-- | 1.1 KB |
| .mailmap | -rw-r--r-- | 4.4 KB |
| COPYING | -rw-r--r-- | 18.3 KB |
| CREDITS | -rw-r--r-- | 92.8 KB |
| Kbuild | -rw-r--r-- | 2.5 KB |
| Kconfig | -rw-r--r-- | 252 bytes |
| MAINTAINERS | -rw-r--r-- | 234.2 KB |
| Makefile | -rw-r--r-- | 46.9 KB |
| README | -rw-r--r-- | 18.3 KB |
| REPORTING-BUGS | -rw-r--r-- | 3.3 KB |
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