Make the error directives uniformly consistent with one another.
Remove surrounding quotes and trailing punctuation, and rephrase
some of the error messages and some of their associated comments
for either brevity or clarity.
The leading blank lines are apparently an artefact of an older source
control system. They are not required and they look like accidents,
because starting a source file with a blank line is not a regular habit
of software developers nowadays.
This is a cherry-pick of commit 37cc20add8fb5b83bb5299a26cd3b41e0f776017
from branch 'libpng18'.
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Following up on the previous commit by Martin Storsjö:
If the availability of ARM Neon is not only known at compile time,
but also expected by the compiler's target architecture, there should
be no further need for a run-time check. In fact, such a check would
be counter-productive.
ARM Neon is expected to be unconditionally available on ARM64.
Issue an #error if PNG_ARM_NEON_CHECK_SUPPORTED is defined on an
ARM64-based platform.
For the plain ARM platforms where ARM Neon checking is not yet
implemented, issue a slightly more descriptive #error, including
a suggested course of action.
implementation of the ARM NEON discovery function to be set at
build-time and provide sample implementations from the current code in the
contrib/arm-neon subdirectory. The __linux__ code has also been changed to
compile and link on Android by using /proc/cpuinfo, and the old linux code
is in contrib/arm-neon/linux-auxv.c. The new code avoids POSIX and Linux
dependencies apart from opening /proc/cpuinfo and is C90 compliant.
requirements of png_modifier are greater than that of png_store and as a
consequence compilation of pngvalid.c results in a warning about increased
alignment requirements because of the bare cast to (png_modifier*). The code
is safe, because the pointer is known to point to a stack allocated
png_modifier, but this change avoids the warning.
Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was
compiled without the CHECK option it defaulted to on, not off.
Check user callback behavior in pngunknown.c. Previous versions compiled
if SAVE_UNKNOWN was not available but did nothing since the callback
was never implemented.
Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes
pnglibconf.h, allowing more of the decisions to be made internally
(pngpriv.h) during the compile. Without this, symbol prefixing is broken
under certain circumstances on ARM platforms. Now only the API parts of
the optimizations ('check' vs 'api') are exposed in the public header files
except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
decision about whether or not to use the optimizations.
prefixing This adds an API to set optimization options externally,
providing an alternative and general solution for the non-portable
run-time tests used by the ARM Neon code. It also makes those tests
compile and link on Android.
The order of settings vs options in pnglibconf.h is reversed to allow
settings to depend on options and options can now set (or override) the
defaults for settings.
option:
--enable-arm-neon=always will stop the run-time checks. New checks
within arm/arm_init.c will cause the code not to be compiled unless
__ARM_NEON__ is set. This should make it fail safe (if someone asks
for it on then the build will fail if it can't be done.)
Fixed ALIGNED_MEMORY support.
