Add versions of wcscpy, wcschr, wcsrchr for power6/power7.

Initially based on the versions found in wcsmbs/* ; these files have
been changed by hand unrolling, and adding some additional variables
to allow some read-ahead to occur, which then relieves some of the
wait-for-increment/wait-for-load/wait-for-compare-results pressure
that was slowing down every iteration through the while-loop.

For 64-bit Power7, These changes give an approx 20% throughput boost
for the wcschr and wcsrchr functions; and approx 40% boost for the
wcscpy function.  32-bit improvements appear to be slightly better
with ~ %30 and ~ %45 respectively.  Results for Power6 closely match
those for power7.

1 files changed, 5 insertions, 2 deletions

diff --git a/NEWS b/NEWS
index d37e5a5920..688dc434f6 100644
--- a/NEWS
+++ b/NEWS
@@ -10,8 +10,8 @@ Version 2.17
 * The following bugs are resolved with this release:
 
   6778, 6808, 9685, 11607, 13717, 13939, 14042, 14090, 14166, 14150, 14151,
-  14154, 14157, 14166, 14173, 14195, 14283, 14298, 14303, 14307, 14328, 14331,
-  14336, 14337, 14347, 14349
+  14154, 14157, 14166, 14173, 14195, 14252, 14283, 14298, 14303, 14307,
+  14328, 14331, 14336, 14337, 14347, 14349
 
 * Support for STT_GNU_IFUNC symbols added for s390 and s390x.
   Optimized versions of memcpy, memset, and memcmp added for System z10 and
@@ -31,6 +31,9 @@ Version 2.17
 * The minimum Linux kernel version that this version of the GNU C Library
   can be used with is 2.6.16.
 
+* Optimizations of string functions memchr, wcschr, wcscpy, and wcsrchr for
+  powerpc POWER7.  Implemented by Will Schmidt.
+
 
 Version 2.16