It seems *sometimes* with aggressive optimizations the combination
`psub(padd(a, b), b)` trick to force rounding is compiled away. Here
we replace with inline assembly to prevent this (I tried `volatile`,
but that leads to additional loads from memory).
Also fixed an edge case for large inputs `a` where adding `b` bumps
the value up a power of two and ends up rounding away more than
just the fractional part. If we are over `2^digits` then just return
the input. This edge case was missed in the test since the test was
comparing approximate equality, which was still satisfied. Adding
a strict equality option catches it.
In SSE, by adding/subtracting 2^MantissaBits, we force rounding according to the
current rounding mode.
For NEON, we use the provided intrinsics for rint/floor/ceil if
available (armv8).
Related to #1969.
Since `numeric_limits<half>::max_exponent` is a static inline constant,
it cannot be directly passed by reference. This triggers a linker error
in recent versions of `g++-powerpc64le`.
Changing `half` to take inputs by value fixes this. Wrapping
`max_exponent` with `int(...)` to make an addressable integer also fixes this
and may help with other custom `Scalar` types down-the-road.
Also eliminated some compile warnings for powerpc.
With !406, we accidentally broke arm 32-bit NEON builds, since
`vsqrt_f32` is only available for 64-bit.
Here we add back the `rsqrt` implementation for 32-bit, relying
on a `prsqrt` implementation with better handling of edge cases.
Note that several of the 32-bit NEON packet tests are currently
failing - either due to denormal handling (NEON versions flush
to zero, but scalar paths don't) or due to accuracy (e.g. sin/cos).
The original will saturate if the input does not fit into an integer
type. Here we fix this, returning the input if it doesn't have
enough precision to have a fractional part.
Also added `pceil` for NEON.
Fixes#1969.
1.Only computing about half of the factors and use complex conjugate symmetry for the rest instead of all to save time.
2.All twiddles are calculated in double because that gives the maximum achievable precision when doing float transforms.
3.Reducing all angles to the range 0<angle<pi/4 which gives even more precision.
The `std::result_of` meta struct is deprecated in C++17 and removed
in C++20. It was still slipping through due to a faulty definition of
`EIGEN_HAS_STD_RESULT_OF`.
Added a new macro `EIGEN_HAS_STD_INVOKE_RESULT` and
`Eigen::internal::invoke_result` implementation with fallback for
pre C++17.
Replaces the `result_of` definition with one based on `std::invoke_result`
for C++17 and higher.
For completeness, added nullary op support for c++03.
Fixes#1850.
CMake complains that the package name does not match when the case
differs, e.g.:
```
CMake Warning (dev) at /usr/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:273 (message):
The package name passed to `find_package_handle_standard_args` (UMFPACK)
does not match the name of the calling package (Umfpack). This can lead to
problems in calling code that expects `find_package` result variables
(e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
cmake/FindUmfpack.cmake:50 (find_package_handle_standard_args)
bench/spbench/CMakeLists.txt:24 (find_package)
This warning is for project developers. Use -Wno-dev to suppress it.
```
Here we rename the libraries to match their true cases.
Added `EIGEN_HAS_STD_HASH` macro, checking for C++11 support and not
running on GPU.
`std::hash<float>` is not a device function, so cannot be used by
`std::hash<bfloat16>`. Removed `EIGEN_DEVICE_FUNC` and only
define if `EIGEN_HAS_STD_HASH`. Same for `half`.
Added `EIGEN_CUDA_HAS_FP16_ARITHMETIC` to improve readability,
eliminate warnings about `EIGEN_CUDA_ARCH` not being defined.
Replaced a couple C-style casts with `reinterpret_cast` for aligned
loading of `half*` to `half2*`. This eliminates `-Wcast-align`
warnings in clang. Although not ideal due to potential type aliasing,
this is how CUDA handles these conversions internally.
