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| author | Matt Turner <mattst88@gmail.com> | 2011-04-27 18:45:30 -0400 |
|---|---|---|
| committer | Matt Turner <mattst88@gmail.com> | 2011-08-03 23:38:03 -0400 |
| commit | b5db8e73ba366befdfa7ceaafa5a3587fff588fb (patch) | |
| tree | 3cf9cd12fd43fab399cb0322a2689d5ec47c1b50 /test/xi2/protocol-xiquerydevice.c | |
| parent | 08dfff92e8d0c2b1726634392c147f6634d1706d (diff) | |
make byte swapping macros less opaque to the optimizer
Text size reduction of ~33k (1.8%):
text data bss dec hex filename
1879739 72212 55328 2007279 1ea0ef hw/xfree86/Xorg.before
1845291 72212 55328 1972831 1e1a5f hw/xfree86/Xorg
On x86[-64], the number of bswap instructions goes up from 5 to 1006.
By defining lswapl as gcc's builtin bswap32, the number of bswap
instructions used goes up to 1025, but the text and binary sizes stay
the same. This tells me that either gcc is
- dumb, and unable to optimize away __builtin_bswap32 when it should
- smart, and able to optimize away the open-coded bswap
Either way, it doesn't matter much.
Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jeremy Huddleston <jeremyhu@apple.com>
Tested-by: Jeremy Huddleston <jeremyhu@apple.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Diffstat (limited to 'test/xi2/protocol-xiquerydevice.c')
0 files changed, 0 insertions, 0 deletions