This avoids having to hardcode the names of devices that don't
support neon.
The devices that don't support neon don't run the armv7 variants
of iOS binaries at all - they would need to be built for the armv6
architecture. (Building for armv6 isn't supported at all in
modern iOS SDKs.)
Therefore we can simply use the __ARM_NEON__ built-in compiler
define to check if NEON code is allowed in the current build,
and have the WelsCPUFeatureDetect function return flags accordingly.
The only thing this disallows is doing an armv6 build which would
optionally enable neon code at runtime if run on an armv7 capable
device, but since Apple allows you to build the same binary for
armv7 separately in the same app bundle, and since armv6 building
isn't even possible in the current iOS SDKs, this isn't really a loss.
This is in contrast to the android builds where the armv7 baseline
does not include NEON.
This avoids the risk of namespace collisions for named semaphores
(where the names are global for the whole machine), on platforms
where we strictly don't need to use the named semaphores.
This unifies the event creation interface, even if the event
name itself is unused on windows, allowing use the exact same
code to initialize events regardless of the actual platform.
Some ifdefs still remain in the event initialization code, since
some events are only used on windows.
The new iOS configuration file welsenc_ios.cfg was committed with
dos newlines originally, while welsenc.cfg was accidentally changed
to dos newlines in f5cd56ea74.
There is no point in doing a timed wait here - there's no work
that we can do if the wait timed out, and sleeping for 1 ms
inbetween doesn't help, it only adds potential extra latency
to reacting to threads that need more work to do.
Typedeffing WELS_EVENT as sem_t* makes the typedef behave similarly
to the windows version (typedeffed as HANDLE), unifying the code
that allocates and uses these event objects (getting rid of
most of the need for separate codepaths and ifdefs).
The caller of the function should not need to know exactly which
implementation of it is being used.
For the variants that don't support detecting the number of cores,
the pNumberOfLogicProcessors parameter can be left untouched
and the caller will use a higher level API for finding it out.
This simplifies all the calling code, and simplifies adding
more implementations of cpu feature detection.
This will make the normal C++ code not run on non-NEON devices at
all, making the runtime CPU feature detection pointless.
Adding -mfpu=neon to CFLAGS is not necessary, it's enough to
add it while building those individual .S files (via ASMFLAGS).
