These are translated from [monocypher](https://monocypher.org/) which
has fairly competitive performance while remaining quite simple.
Initial performance comparision:
Zig:
Poly1305: 1423 MiB/s
X25519: 8671 exchanges per second
Monocypher:
Poly1305: 1567 MiB/s
X25519: 10539 exchanges per second
There is room for improvement and no real effort has been made at all in
optimization beyond a direct translation.
* add std.event.RwLock and std.event.RwLocked
* std.debug.warn does its printing locked
* add std.Mutex, however it's currently implemented as a spinlock
* rename std.event.Group.cancelAll to std.event.Group.deinit and change
the docs and assumptions.
* add std.HashMap.clone
* introduce std.atomic.Int
* add src-self-hosted/test.zig which is tested by the main test suite
- it fully utilizes the multithreaded async/await event loop so the
tests should Go Fast
* `stage2/bin/zig build-obj test.zig` is able to spit out an error if 2 exported
functions collide
* ability for `zig test` to accept `--object` and `--assembly`
arguments
* std.build: TestStep supports addLibPath and addObjectFile
Git was called in the build directory and not the source directory.
This works fine when the build directory resides within the source
repository, but doesn't work for out-of-source builds. Example:
```
~/zigbuild$ cmake ../zig
fatal: not a git repository (or any of the parent directories): .git
Configuring zig version 0.2.0+
```
Use Git's `-C <path>` flag to always point to the source directory so
that it doesn't matter where the build directory lives.
Add support for half-precision floating point operations.
Introduce `__extendhfsf2` and `__truncsfhf2` in std/special/compiler_rt.
Add `__gnu_h2f_ieee` and `__gnu_f2h_ieee` as aliases that are used in
Windows builds.
The logic in std/special/compiler_rt/extendXfYf2.zig has been reworked
and can now operate on 16 bits floating point types.
`extendXfYf2()` and `truncXfYf2()` are marked `inline` to work around
a not entirely understood stack alignment issue on Windows when calling
the f16 versions of the builtins.
closes#1122
when the integer part does not fit in the destination integer type
* Also fix incorrect safety triggered for integer casting an
`i32` to a `u7`. closes#1138
* adds compiler-rt function: `__floatuntidf`
A few notes on the implementation:
- Any unsigned power of two integer type less than 64 bits in size is supported
as a Limb type.
- The algorithms used are kept simple for the moment. More complicated
algorithms are generally only more useful as integer sizes increase a
lot and I don't expect our current usage to be used for this purpose
just yet.
- All branches (practically) have been covered by tests.
See 986a2b3243/bench
for rough performance comparison numbers.
Closes#364.