Added warning with supported OSes list for VSX check
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4a15c71..5d2a364 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -132,6 +132,8 @@
add_definitions(-DPNG_POWERPC_VSX_OPT=2)
elseif(${PNG_POWERPC_VSX} STREQUAL "check")
add_definitions(-DPNG_POWERPC_VSX_CHECK_SUPPORTED)
+ message(WARNING
+ " Please check contrib/powerpc/README file for the list of supported OSes.")
endif()
else()
add_definitions(-DPNG_POWERPC_VSX_OPT=0)
diff --git a/configure.ac b/configure.ac
index 73f7183..e19474e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -448,7 +448,9 @@
enable_powerpc_vsx=no;;
check)
AC_DEFINE([PNG_POWERPC_VSX_CHECK_SUPPORTED], [],
- [Check for POWERPC VSX support at run-time]);;
+ [Check for POWERPC VSX support at run-time])
+ AC_MSG_WARN([--enable-powerpc-vsx Please check contrib/powerpc/README file]
+ [for the list of supported OSes.]);;
api)
AC_DEFINE([PNG_POWERPC_VSX_API_SUPPORTED], [],
[Turn on POWERPC VSX optimizations at run-time]);;
diff --git a/contrib/powerpc-vsx/README b/contrib/powerpc-vsx/README
new file mode 100644
index 0000000..e566147
--- /dev/null
+++ b/contrib/powerpc-vsx/README
@@ -0,0 +1,81 @@
+OPERATING SYSTEM SPECIFIC POWERPC DETECTION
+--------------------------------------------
+
+Detection of the ability to execute POWERPC on processor requires
+operating system support. (The information is not available in user mode.)
+
+Currently only this feature is supported only for linux platform.
+
+HOW TO USE THIS
+---------------
+
+This directory contains C code fragments that can be included in powerpc/powerpc_init.c
+by setting the macro PNG_POWERPC_VSX_FILE to the file name in "" or <> at build
+time. This setting is not recorded in pnglibconf.h and can be changed simply by
+rebuilding arm/arm_init.o with the required macro definition.
+
+For any of this code to be used the POWERPC code must be enabled and run time
+checks must be supported. I.e.:
+
+#if PNG_POWERPC_VSX_OPT > 0
+#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED
+
+This is done in a 'configure' build by passing configure the argument:
+
+ --enable-powerpc-vsx=check
+
+FILE FORMAT
+-----------
+
+Each file documents its testing status as of the last time it was tested (which
+may have been a long time ago):
+
+STATUS: one of:
+ SUPPORTED: This indicates that the file is included in the regularly
+ performed test builds and bugs are fixed when discovered.
+ COMPILED: This indicates that the code did compile at least once. See the
+ more detailed description for the extent to which the result was
+ successful.
+ TESTED: This means the code was fully compiled into the libpng test programs
+ and these were run at least once.
+
+BUG REPORTS: an email address to which to send reports of problems
+
+The file is a fragment of C code. It should not define any 'extern' symbols;
+everything should be static. It must define the function:
+
+static int png_have_vsx(png_structp png_ptr);
+
+That function must return 1 if ARM NEON instructions are supported, 0 if not.
+It must not execute png_error unless it detects a bug. A png_error will prevent
+the reading of the PNG and in the future, writing too.
+
+BUG REPORTS
+-----------
+
+If you mail a bug report for any file that is not SUPPORTED there may only be
+limited response. Consider fixing it and sending a patch to fix the problem -
+this is more likely to result in action.
+
+CONTRIBUTIONS
+-------------
+
+You may send contributions of new implementations to
+png-mng-implement@sourceforge.net. Please write code in strict C90 C where
+possible. Obviously OS dependencies are to be expected. If you submit code you
+must have the authors permission and it must have a license that is acceptable
+to the current maintainer; in particular that license must permit modification
+and redistribution.
+
+Please try to make the contribution a single file and give the file a clear and
+unambiguous name that identifies the target OS. If multiple files really are
+required put them all in a sub-directory.
+
+You must also be prepared to handle bug reports from users of the code, either
+by joining the png-mng-implement mailing list or by providing an email for the
+"BUG REPORTS" entry or both. Please make sure that the header of the file
+contains the STATUS and BUG REPORTS fields as above.
+
+Please list the OS requirements as precisely as possible. Ideally you should
+also list the environment in which the code has been tested and certainly list
+any environments where you suspect it might not work.
diff --git a/contrib/powerpc-vsx/linux.c b/contrib/powerpc-vsx/linux.c
index f54f65f..8fc76e3 100644
--- a/contrib/powerpc-vsx/linux.c
+++ b/contrib/powerpc-vsx/linux.c
@@ -7,7 +7,7 @@
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
- * STATUS: COMPILED
+ * STATUS: TESTED
* BUG REPORTS: png-mng-implement@sourceforge.net
*
* png_have_vsx implemented for Linux by reading the widely available
diff --git a/contrib/powerpc-vsx/linux_aux.c b/contrib/powerpc-vsx/linux_aux.c
index 058bb02..d946d6c 100644
--- a/contrib/powerpc-vsx/linux_aux.c
+++ b/contrib/powerpc-vsx/linux_aux.c
@@ -7,7 +7,7 @@
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
- * STATUS: COMPILED
+ * STATUS: TESTED
* BUG REPORTS: png-mng-implement@sourceforge.net
*
* png_have_vsx implemented for Linux by using the auxiliary vector mechanism.
