glibc/ports
Chris Metcalf cd84016efe Optimize tile (mostly tilegx) memcpy and memmove performance.
- Override <memcopy.h> so we use full 8-byte word copies on tilegx32
  for memmove, then use op_t in memcpy instead of the previous
  locally-defined word_t just to avoid proliferating identical types.
- Fix bug in memcpy prefetch that caused us to never prefetch past
  the first cache line.
- Optimize misaligned memcpy by inlining _wordcopy_fwd_dest_aligned
  instead of just doing a dumb word-at-a-time copy.
- Make memcpy safe for forward copies by doing all the loads from
  a given cache line prior to doing a wh64 (cache line zero-fill)
  on the destination.  Remove now-redundant src == dst check.
- Copy and optimize the generic wordcopy.c routines to use the tile
  "double align" instruction instead of the MERGE macro; to avoid
  offset addressing mode (which tile doesn't have) by rewriting the
  pointer math to load and store with a zero index; and to use
  post-increment addresses in the inner loops to improve scheduling.
2012-11-06 09:24:19 -05:00
..
sysdeps Optimize tile (mostly tilegx) memcpy and memmove performance. 2012-11-06 09:24:19 -05:00
ChangeLog
ChangeLog.aix
ChangeLog.alpha
ChangeLog.am33
ChangeLog.arm
ChangeLog.cris
ChangeLog.hppa
ChangeLog.ia64
ChangeLog.linux-generic
ChangeLog.m68k
ChangeLog.mips
ChangeLog.powerpc
ChangeLog.tile Optimize tile (mostly tilegx) memcpy and memmove performance. 2012-11-06 09:24:19 -05:00
README

This is the glibc ports repository, an add-on for the GNU C Library (glibc).
It contains code that is not maintained in the official glibc source tree.

This includes working ports to GNU/Linux on some machine architectures that
are not maintained in the official glibc source tree.  It also includes
some code once used by old libc ports now defunct, which has been abandoned
but may be useful for some future porter to examine.  It may also include
some optimized functions tailored for specific CPU implementations of an
architecture, to be selected using --with-cpu.

The ports repository is cooperatively maintained by volunteers on the
<libc-ports@sourceware.org> mailing list, and housed in a separate
ports git repository.  See
http://www.gnu.org/software/libc/download.html for details on using
git.  To report a bug in code housed in the ports repository, please
go to http://sources.redhat.com/bugzilla/ and file a bug report under
the glibc "ports" component.

An add-on for an individual port can be made from just the sysdeps/
subdirectories containing the port's code.  You may want to include a
README and Banner of your own talking about your port's code in particular,
rather than the generic ones here.

The real source code for any ports is found in the sysdeps/ subdirectories.
These should be exactly what would go into the main libc source tree if you
were to incorporate it directly.  The only exceptions are the files
sysdeps/*/preconfigure and sysdeps/*/preconfigure.in; these are fragments
used by this add-on's configure fragment.  The purpose of these is to set
$base_machine et al when the main libc configure's defaults are not right
for some machine.  Everything else can and should be done from a normal
sysdeps/.../configure fragment that is used only when the configuration
selects that sysdeps subdirectory.  Each port that requires some special
treatment before the sysdeps directory list is calculated, should add a
sysdeps/CPU/preconfigure file; this can either be written by hand or
generated by Autoconf from sysdeps/CPU/preconfigure.in, and follow the
rules for glibc add-on configure fragments.  No preconfigure file should do
anything on an unrelated configuration, so that disparate ports can be put
into a single add-on without interfering with each other.  Files that
would go in scripts/data/ for libc go in data/ in ports.

Like all glibc add-ons, this must be used by specifying the directory in
the --enable-add-ons option when running glibc's configure script.

The GNU C Library is free software.  See the file COPYING.LIB in the
libc repository for copying conditions, and LICENSES for notices about
a few contributions that require these additional notices to be
distributed.  License copyright years may be listed using range
notation, e.g., 2000-2011, indicating that every year in the range,
inclusive, is a copyrightable year that would otherwise be listed
individually.