History log of /freebsd-12.1/lib/libc/string/strlen.c (Results 1 – 13 of 13)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: release/12.2.0, release/11.4.0, release/12.1.0, release/11.3.0, release/12.0.0, release/11.2.0
# b6f7731d 10-May-2018 Xin LI <[email protected]>

Remove "All rights reserved" from my files.

See r333391 for the rationale.

MFC after: 1 week


# d915a14e 25-Nov-2017 Pedro F. Giffuni <[email protected]>

libc: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
p

libc: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

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Revision tags: release/10.4.0, release/11.1.0, release/11.0.1, release/11.0.0, release/10.3.0, release/10.2.0, release/10.1.0, release/9.3.0, release/10.0.0, release/9.2.0, release/8.4.0, release/9.1.0, release/8.3.0, release/7.4.0, release/8.2.0, release/8.1.0
# 42ddb8f1 13-May-2010 Xin LI <[email protected]>

MFC r205099-205100,205108:

Two optimizations to MI strlen(3) inspired by David S. Miller's
blog posting [1].

- Use word-sized test for unaligned pointer before working
the hard way.

Memory

MFC r205099-205100,205108:

Two optimizations to MI strlen(3) inspired by David S. Miller's
blog posting [1].

- Use word-sized test for unaligned pointer before working
the hard way.

Memory page boundary is always integral multiple of a word
alignment boundary. Therefore, if we can access memory
referenced by pointer p, then (p & ~word mask) must be also
accessible.

- Better utilization of multi-issue processor's ability of
concurrency.

The previous implementation utilized a formular that must be
executed sequentially. However, the ~, & and - operations can
actually be caculated at the same time when the operand were
different and unrelated.

The original Hacker's Delight formular also offered consistent
performance regardless whether the input would contain
characters with their highest-bit set, as it catches real
nul characters only.

These two optimizations has shown further improvements over the
previous implementation on microbenchmarks on i386 and amd64 CPU
including Pentium 4, Core Duo 2 and i7.

[1] http://vger.kernel.org/~davem/cgi-bin/blog.cgi/2010/03/08#strlen_1

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Revision tags: release/7.3.0
# 87c88b26 13-Mar-2010 Xin LI <[email protected]>

Correct bugs fixed but not merged from my own tree.

Pointy hat to: delphij
MFC after: 1 month


# 51e48ff2 12-Mar-2010 Xin LI <[email protected]>

Follow up commit to reindent the code.

MFC after: 1 month


# dabae226 12-Mar-2010 Xin LI <[email protected]>

Two optimizations to MI strlen(3) inspired by David S. Miller's
blog posting [1].

- Use word-sized test for unaligned pointer before working
the hard way.

Memory page boundary is always inte

Two optimizations to MI strlen(3) inspired by David S. Miller's
blog posting [1].

- Use word-sized test for unaligned pointer before working
the hard way.

Memory page boundary is always integral multiple of a word
alignment boundary. Therefore, if we can access memory
referenced by pointer p, then (p & ~word mask) must be also
accessible.

- Better utilization of multi-issue processor's ability of
concurrency.

The previous implementation utilized a formular that must be
executed sequentially. However, the ~, & and - operations can
actually be caculated at the same time when the operand were
different and unrelated.

The original Hacker's Delight formular also offered consistent
performance regardless whether the input would contain
characters with their highest-bit set, as it catches real
nul characters only.

These two optimizations has shown further improvements over the
previous implementation on microbenchmarks on i386 and amd64 CPU
including Pentium 4, Core Duo 2 and i7.

[1] http://vger.kernel.org/~davem/cgi-bin/blog.cgi/2010/03/08#strlen_1

MFC after: 1 month

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Revision tags: release/8.0.0, release/7.2.0
# 481101b8 26-Jan-2009 Xin LI <[email protected]>

- Fix grammar. [1]
- Use the correct term 'long mode'. [2]
- style(9) for return value. [3]

Submitted by: Ben Kaduk <minimarmot gmail com> [1],
obrien [2], scf [3]


# 4c6a6021 25-Jan-2009 Xin LI <[email protected]>

Rewrite of MI strlen(3) in a way that can better utilize modern hardware by
reducing branches and doing word-sized operation.

The idea is taken from J.T. Conklin's x86_64 optimized version of strlen

Rewrite of MI strlen(3) in a way that can better utilize modern hardware by
reducing branches and doing word-sized operation.

The idea is taken from J.T. Conklin's x86_64 optimized version of strlen(3)
for NetBSD, and reimplemented in C by me.

Discussed on: -arch@

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Revision tags: release/7.1.0, release/6.4.0, release/7.0.0, release/6.3.0, release/6.2.0
# c879ae35 09-Jan-2007 Warner Losh <[email protected]>

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.


Revision tags: release/5.5.0, release/6.1.0, release/6.0.0, release/5.4.0, release/4.11.0, release/5.3.0, release/4.10.0, release/5.2.1, release/5.2.0, release/4.9.0, release/5.1.0, release/4.8.0, release/5.0.0, release/4.6.2
# 8fb3f3f6 21-Mar-2002 David E. O'Brien <[email protected]>

Remove 'register' keyword.


# de5fe5d5 07-Nov-2001 David E. O'Brien <[email protected]>

rcsid[]->__FBSDID


# 5864b79c 24-May-2001 David E. O'Brien <[email protected]>

Make the rcsid and FreeBSD IDs more sane in the wcs* and wmem* files.
Do the same for the non-wcs*/wmem* files while I'm here.


Revision tags: release/4.3.0, release/1.1.5.1_cvs
# 58f0484f 27-May-1994 Rodney W. Grimes <[email protected]>

BSD 4.4 Lite Lib Sources