xref: /freebsd-src/contrib/cortex-strings/README (revision 8c4282b370bd66908b45b6a223226a9fc2b69d57)

= Cortex-A String Routines =

This package contains optimised string routines including memcpy(), memset(),
strcpy(), strlen() for the ARM Cortex-A series of cores.

Various implementations of these routines are provided, including generic
implementations for ARMv7-A cores with/without Neon, Thumb2 implementations
and generic implementations for cores supporting AArch64.

== Getting started ==
First configure and then install libcortex-strings.so.  To make other
applications use this library, either add -lcortex-strings to the link
command or use LD_PRELOAD to load the library into existing applications.

Our intent is to get these routines into the common C libraries such
as GLIBC, Bionic, and Newlib.  Your system may already include them!

== Contents ==
 * src/  contains the routines themselves
 * tests/  contains the unit tests
 * reference/  contains reference copies of other ARM-focused
   implementations gathered from around the Internet
 * benchmarks/  contains various benchmarks, tools, and scripts used to
   check and report on the different implementations.

The src directory contains different variants organised by the
implementation they run on and optional features used.  For example:
  * src/thumb-2  contains generic non-NEON routines for AArch32 (with Thumb-2).
  * src/arm  contains tuned routines for Cortex-A class processors.
  * src/aarch64  contains generic routines for AArch64.
  * src/thumb  contains generic routines for armv6-M (with Thumb).

== Reference versions ==
reference/ contains versions collected from various popular Open
Source libraries.  These have been modified for use in benchmarking.
Please refer to the individual files for any licensing terms.

The routines were collected from the following releases:
 * EGLIBC 2.13
 * Newlib 1.19.0
 * Bionic android-2.3.5_r1

== Licensing ==
All Linaro-authored routines are under the modified BSD license:

Copyright (c) 2011, Linaro Limited
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the Linaro nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

All ARM-authored routines are under the modified BSD license:

Copyright (c) 2014 ARM Ltd
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the Linaro nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

All third party routines are under a GPL compatible license.

== Notes and Limitations ==
Some of the implementations have been collected from other
projects and have a variety of licenses and copyright holders.

== Style ==
Assembly code attempts to follow the GLIBC coding convetions.  They
are:
 * Copyright headers in C style comment blocks
 * Instructions indented with one tab
 * Operands indented with one tab
 * Text is wrapped at 70 characters
 * End of line comments are fine