Unfortunately, MSVC only accepts __stdcall after the return type, while
gcc only accepts __attribute__((visibility("default"))) before the
return type. So we need a macro in each location.
Also, MSVC doesn't define __i386__; that's gcc specific. So instead use
'_WIN32 && !_WIN64' to detect 32-bit Windows.
Use 'volatile' for the CPU feature masks and dispatched function
pointers. We don't need memory barriers for them, so 'volatile' is good
enough to stop the compiler from inserting bogus reads/writes.
Move the x86 and ARM-specific code into their own directories to prevent
it from cluttering up the main library. This will make it a bit easier
to add new architecture-specific code.
But to avoid complicating things too much for people who aren't using
the provided Makefile, we still just compile all .c files for all
architectures (irrelevant ones end up #ifdef'ed out), and the headers
are included explicitly for each architecture so that an
architecture-specific include path isn't needed. So, now people just
need to compile both lib/*.c and lib/*/*.c instead of only lib/*.c.
Replace COMPILER_SUPPORTS_TARGET_INTRINSICS with macros for the
individual features, since COMPILER_SUPPORTS_TARGET_INTRINSICS was
x86-specific and would cause confusion when we try to use intrinsics in
'target' functions for other architectures.
I've decided to simplify and standardize the licensing status for the
library by using the MIT license instead of CC0 (a.k.a. "public
domain"). This eliminates the somewhat controversial 4(a) clause in
CC0, and, for this and other reasons, should (somewhat ironically) make
it easier for some people to use and contribute to the project.
Note: copyright will apply to new changes and to new versions of the
work as a whole. Of course, versions previously released as public
domain remain public domain where legally recognized.
* Bring in common headers and program code from xpack project
* Move program code to programs/
* Move library code to lib/
* GNU89 and MSVC2010 compatibility
* Other changes
