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| author | Will Schmidt <will_schmidt@vnet.ibm.com> | 2012-08-21 14:20:55 -0500 |
|---|---|---|
| committer | Ryan S. Arnold <rsa@linux.vnet.ibm.com> | 2012-08-21 14:20:55 -0500 |
| commit | 14a50c9d238a8d79d48193482ed9a2be52d1dc3d (patch) | |
| tree | 046c03b3bf03143c65e3f4eab969391df13e4dd1 /ChangeLog | |
| parent | 696da85994af013ae1e3e8ad3bb016793f9b2c5d (diff) | |
| download | glibc-14a50c9d238a8d79d48193482ed9a2be52d1dc3d.tar.gz glibc-14a50c9d238a8d79d48193482ed9a2be52d1dc3d.tar.xz glibc-14a50c9d238a8d79d48193482ed9a2be52d1dc3d.zip | |
[Powerpc] Tune/optimize powerpc{32,64}/power7/memchr.S.
Assorted tweaking, twisting and tuning to squeeze a few additional cycles out of the memchr code. Changes include bypassing the shift pairs (sld,srd) when they are not required, and unrolling the small_loop that handles short and trailing strings. Per scrollpipe data measuring aligned strings for 64-bit, these changes save between five and eight cycles (9-13% overall) for short strings (<32), Longer aligned strings see slight improvement of 1-3% due to bypassing the shifts and the instruction rearranging.
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 0c34ac30cf..12e5b4c2df 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2012-08-21 Will Schmidt <will_schmidt@vnet.ibm.com> + + * sysdeps/powerpc/powerpc64/power7/memchr.S: Unrolled short loop and + slight instruction rearrangements per scrollpipe analysis. + * sysdeps/powerpc/powerpc64/power7/memchr.S: Likewise. + 2012-08-20 Roland McGrath <roland@hack.frob.com> * manual/syslog.texi (syslog; vsyslog, closelog): |