powerpc64: Add POWER8 strnlen
commit18b6e2c86ce03c9be8ee0a53840fe5d533de22b3
authorWainer dos Santos Moschetta <wainersm@linux.vnet.ibm.com>
Wed, 5 Apr 2017 13:24:24 +0000 (5 10:24 -0300)
committerTulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
Wed, 5 Apr 2017 13:26:58 +0000 (5 10:26 -0300)
tree1e58ed4cc0d2886d01223510f11ccf2889a719dd
parentb2b1ea8b777c2f1362d41ee34089104f535e9903
powerpc64: Add POWER8 strnlen

Added strnlen POWER8 otimized for long strings. It delivers
same performance as POWER7 implementation for short strings.

This takes advantage of reasonably performing unaligned loads
and bit permutes to check the first 1-16 bytes until
quadword aligned, then checks in 64 bytes strides until unsafe,
then 16 bytes, truncating the count if need be.

Likewise, the POWER7 code is recycled for less than 32 bytes strings.

Tested on ppc64 and ppc64le.

* sysdeps/powerpc/powerpc64/multiarch/Makefile
(sysdep_routines): Add strnlen-power8.
* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
(strnlen): Add __strnlen_power8 to list of strnlen functions.
* sysdeps/powerpc/powerpc64/multiarch/strnlen-power8.S:
New file.
* sysdeps/powerpc/powerpc64/multiarch/strnlen.c
(__strnlen): Add __strnlen_power8 to ifunc list.
* sysdeps/powerpc/powerpc64/power8/strnlen.S: New file.
ChangeLog
sysdeps/powerpc/powerpc64/multiarch/Makefile
sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
sysdeps/powerpc/powerpc64/multiarch/strnlen-power8.S [copied from sysdeps/powerpc/powerpc64/multiarch/strnlen.c with 53% similarity]
sysdeps/powerpc/powerpc64/multiarch/strnlen.c
sysdeps/powerpc/powerpc64/power8/strnlen.S [new file with mode: 0644]