This file contains hand-coded assembler implementations of the filter
functions for 32-bit Arm platforms. These are only used when the
compiler doesn't support neon intrinsics (added to GCC 4.3 in 2008) or
is exactly GCC 4.5.4 (released 2012), both of which are sufficiently
unlikely to be true that it's fair to say the assembler is no longer
used.
This commit deletes filter_neon.S and removes the now obsolete
preprocessor logic in pngpriv.h.
Signed-off-by: Bill Roberts <bill.roberts@arm.com>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
This fixes the bug https://github.com/pnggroup/libpng/issues/505
"libpng does not support PAC/BTI on aarch64 targets" which arises
because the build mechanisms (both cmake and configure) assemble
arm/filter_neon.S even though it ends up completely empty. The empty
file effectively poisons the so that the PAC/BTI support gets disabled.
The fix is minimal; it simply removes arm/filter_neon.S from the list of
sources included in the 64-bit ARM builds build. Note that this was
already done in cmake for MSVC - it's not clear whether this change was
a partial fix for the same issue.
This version of the fix ONLY affects aarch64 (arm64) builds; 32-bit ARM
systems can still invoke the assembler if required and, indeed, there
should be no change whatsover to those builds.
The assembler code could not be used on 64-bit systems in any case so
in practice there is no material change to 64-bit builds either.
TESTING: pull the changes then type "autoreconf" if using configure (not
required for cmake).
TESTS: cmake has not been tested because cross-builds with cmake
currently fail to find the zlib installation from the cmake system root
path. The following has been tested with configure cross builds:
armv7-linux-gnueabi [no neon support]
armv7a-linux-gnueabi [no neon support]
armv7a-hardfloat-linux-gnueabi [neon support not enabled]
armv7a-hardfloat-linux-gnueabi -mfpu=neon [uses intrinics]
armv7a-hardfloat-linux-gnueabi -mfpu=neon
-DPNG_ARM_NEON_IMPLEMENTATION=2 [uses assembler]
aarch64-linux-gnu [uses intrinsics]
aarch64-linux-gnu -DPNG_ARM_NEON_OPT=0 [neon support disabled]
Signed-off-by: John Bowler <jbowler@acm.org>
In the configure script, checking whether the LoongArch LSX intrinsics
are supported by the compiler was done unconditionally, regardless of
the targetted host platform. Compared to how we support the other SIMD
platforms and compilers, this is rather unconventional.
We are placing this check under the guard of its own platform, for the
time being. A full solution, in line with the rest of the configure.ac
patterns concering SIMD optimizations, is TODO.
We also do an overall cleanup in the SIMD section of configure.ac, and,
finally, we regenerate the configure script.
Declare AWK explicitly via the AC_ARG_VAR directive, in order to make
it "precious", and to include it in the list of influential variables
at the end of the configure help text.
Rephrase a few comments and config traces.
Finally, regenerate the configure script.
Move all Autoconf macro files (except for those that need to be in
the top-level directory) to their own subdirectory scripts/autoconf/
In this commit, we introduce a better way to organize the scripts dir,
and we make a better separation between the build scripts under the
libpng license vs. the build scripts that fall under other licenses.
Please see scripts/autoconf/README.md for more information.
Rename
--enable-png-tests/--disable-png-tests
--enable-png-tools/--disable-png-tools
to
--enable-tests/--disable-tests
--enable-tools/--disable-tools
respectively.
While the `PNG_` prefix is necessary in CMakeLists.txt, a corresponding
`--...-png-` option qualifier would be redundant in a configure script.
This PR adds two set of options to the configure script:
--enable-png-tests/--disable-png-tests
and
--enable-png-tools/--disable-png-tools
By using this feature, a user will be allowed to build only library if
needed, which will be useful on platforms not able to build the tools
and/or the tests.
This PR leaves the existing behaviour as default setting, by building
both the tools and the tests if the options are not used.
CMakeLists.txt already supports this feature with the options PNG_TESTS
and PNG_EXECUTABLES. After this commit, Autotools will provide the same
feature.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
