[PATCH 00/11] Improve generic string routines

[Richard Henderson <rth at twiddle dot net>]

The idea here was to improve hppa performance without going all
the way to hand-written assembly (at least for now) so that other
minor architectures could benefit.

The main improvement, IMO, is pulling out all of the scattered
"magic" byte tests to a new header, haszero.h.

I'll note that the comments regarding these tests are in fact out
of date -- they speak of a number 0x7efefeff which does not appear
(we use -0x01010101 or 0xfefefeff), and a test misfire which cannot
actually occur (presumably because we changed algorithms).

This header can then be easily overridden for a target to use a
cheaper zero-byte test, if one exists.  I've provided such for
both hppa and alpha.

I've tested this for hppa and alpha, both under qemu.  While I
cannot provide non-simulated numbers for benchmark improvements,
I'm confident that the real hardware ought to agree in magnitude.


r~



Richard Henderson (11):
  Improve generic strlen
  Improve generic strchr
  Improve generic memchr
  Improve generic strchrnul
  Improve generic strrchr
  Improve generic memrchr
  Improve generic strnlen
  Improve generic strcmp
  hppa: Add memcopy.h
  hppa: Add haszero.h and whichzero.h
  alpha: Add haszero.h and whichzero.h

 string/memchr.c               | 118 +++++++--------------------
 string/memrchr.c              | 180 +++++++-----------------------------------
 string/strchr.c               | 144 +++++----------------------------
 string/strchrnul.c            | 126 ++++-------------------------
 string/strcmp.c               | 100 +++++++++++++++++++++--
 string/strlen.c               |  80 ++++---------------
 string/strnlen.c              | 125 +++++------------------------
 string/strrchr.c              |  67 +++++++++++++---
 sysdeps/alpha/haszero.h       |  36 +++++++++
 sysdeps/alpha/whichzero.h     |  55 +++++++++++++
 sysdeps/generic/extractbyte.h |  34 ++++++++
 sysdeps/generic/haszero.h     |  42 ++++++++++
 sysdeps/generic/whichzero.h   |  67 ++++++++++++++++
 sysdeps/hppa/haszero.h        |  82 +++++++++++++++++++
 sysdeps/hppa/memcopy.h        |  44 +++++++++++
 sysdeps/hppa/whichzero.h      |  70 ++++++++++++++++
 16 files changed, 707 insertions(+), 663 deletions(-)
 create mode 100644 sysdeps/alpha/haszero.h
 create mode 100644 sysdeps/alpha/whichzero.h
 create mode 100644 sysdeps/generic/extractbyte.h
 create mode 100644 sysdeps/generic/haszero.h
 create mode 100644 sysdeps/generic/whichzero.h
 create mode 100644 sysdeps/hppa/haszero.h
 create mode 100644 sysdeps/hppa/memcopy.h
 create mode 100644 sysdeps/hppa/whichzero.h

-- 
2.9.3