* Attempt to fix tests on master
* Make all doctests use items from the real `std` rather than this
crate, it's just easier
* Handle debuginfo weirdness by flagging functions as `no_mangle` that
we're looking for instructions within.
* Handle double undescores in symbol names
After using MMX intrinsics the FPU must be
cleared by using _mm_empty() before interfacing
with any x87 code.
This commit makes the simd_test macro automatically do that
when one of the features enabled is "mmx".
This commit:
* renames `coresimd` to `core_arch` and `stdsimd` to `std_detect`
* `std_detect` does no longer depend on `core_arch` - it is a freestanding
`no_std` library that only depends on `core` - it is renamed to `std_detect`
* moves the top-level coresimd and stdsimd directories into the appropriate
crates/... directories - this simplifies creating crate.io releases of these crates
* moves the top-level `coresimd` and `stdsimd` sub-directories into their
corresponding crates in `crates/{core_arch, std_detect}`.
This intrinsic isn't actually specified by Intel, but it's something
gated with CPUID and can otherwise be a useful thing to have when
building primitives!
There exists an `AtomicU128` type in the standard library but it's only
exposed currently (and it's unstable) when a platform fully supports
128-bit atomics. The x86_64 architecture does not support it *unless*
the `cmpxchg16b` instruction is available, and it isn't always available!
This commit is also a proposal for how we can include support for
128-bit atomics in the standard library on relevant platforms. I'm
thinking that we'll expose this one low-level intrinsic in
`std::arch::x86_64`, and then if desired a crate on crates.io can build
`AtomicU128` from this API.
In any case this is all unstable regardless!
