Adding the term e*ln(2) is split into two step for no obvious reason.
This dates back to the original Cephes code from which the algorithm is adapted.
It appears that this was done in Cephes to prevent the compiler from reordering
the addition of the 3 terms in the approximation
log(1+x) ~= x - 0.5*x^2 + x^3*P(x)/Q(x)
which must be added in reverse order since |x| < (sqrt(2)-1).
This allows rewriting the code to just 2 pmadd and 1 padd instructions,
which on a Skylake processor speeds up the code by 5-7%.
The current impl corrupts the comparison masks when converting
from float back to bfloat16. The resulting masks are then
no longer all zeros or all ones, which breaks when used with
`pselect` (e.g. in `pmin<PropagateNumbers>`). This was
causing `packetmath_15` to fail on arm.
Introducing a simple `F32MaskToBf16Mask` corrects this (takes
the lower 16-bits for each float mask).
Prior to this fix, `TensorContractionGpu` and the `cxx11_tensor_of_float16_gpu`
test are broken, as well as several ops in Tensorflow. The gpu functions
`__shfl*` became ambiguous now that `Eigen::half` implicitly converts to float.
Here we add the required specializations.
`bit_cast` cannot be `constexpr`, so we need to remove `EIGEN_CONSTEXPR` from
`raw_half_as_uint16(...)`. This shouldn't affect anything else, since
it is only used in `a bit_cast<uint16_t,half>()` which is not itself
`constexpr`.
Fixes#2077.
This allows the `packetmath` tests to pass for AVX512 on skylake.
Made `half` and `bfloat16` consistent in terms of ops they support.
Note the `log` tests are currently disabled for `bfloat16` since
they fail due to poor precision (they were previously disabled for
`Packet8bf` via test function specialization -- I just removed that
specialization and disabled it in the generic test).
part of the class signature is lost due to a problem with forward
declarations. The problem is probably caused by doxygen bug #7689.
It is confirmed to be fixed in doxygen >= 1.8.19.
Allows exclusion of doc and related targets to help when using eigen via add_subdirectory().
Requested by:
https://gitlab.com/libeigen/eigen/-/issues/1842
Also required making EIGEN_TEST_BUILD_DOCUMENTATION a dependent option on EIGEN_BUILD_DOC. This ensures documentation targets are properly defined when EIGEN_TEST_BUILD_DOCUMENTATION is ON.
The `half_float` test was failing with `-mcpu=cortex-a55` (native `__fp16`) due
to a bad NaN bit-pattern comparison (in the case of casting a float to `__fp16`,
the signaling `NaN` is quieted). There was also an inconsistency between
`numeric_limits<half>::quiet_NaN()` and `NumTraits::quiet_NaN()`. Here we
correct the inconsistency and compare NaNs according to the IEEE 754
definition.
Also modified the `bfloat16_float` test to match.
Tested with `cortex-a53` and `cortex-a55`.
This fixes some gcc warnings such as:
```
Eigen/src/Core/GenericPacketMath.h:655:63: warning: implicit conversion turns floating-point number into bool: 'typename __gnu_cxx::__enable_if<__is_integer<bool>::__value, double>::__type' (aka 'double') to 'bool' [-Wimplicit-conversion-floating-point-to-bool]
Packet psqrt(const Packet& a) { EIGEN_USING_STD(sqrt); return sqrt(a); }
```
Details:
- Added `scalar_sqrt_op<bool>` (`-Wimplicit-conversion-floating-point-to-bool`).
- Added `scalar_square_op<bool>` and `scalar_cube_op<bool>`
specializations (`-Wint-in-bool-context`)
- Deprecated above specialized ops for bool.
- Modified `cxx11_tensor_block_eval` to specialize generator for
booleans (`-Wint-in-bool-context`) and to use `abs` instead of `square` to
avoid deprecated bool ops.
Minimal implementation of AVX `Eigen::half` ops to bring in line
with `bfloat16`. Allows `packetmath_13` to pass.
Also adjusted `bfloat16` packet traits to match the supported set
of ops (e.g. Bessel is not actually implemented).
The `half_float` test was failing with `-mcpu=cortex-a55` (native `__fp16`) due
to a bad NaN bit-pattern comparison (in the case of casting a float to `__fp16`,
the signaling `NaN` is quieted). There was also an inconsistency between
`numeric_limits<half>::quiet_NaN()` and `NumTraits::quiet_NaN()`. Here we
correct the inconsistency and compare NaNs according to the IEEE 754
definition.
Also modified the `bfloat16_float` test to match.
Tested with `cortex-a53` and `cortex-a55`.
The AVX half implementation is incomplete, causing the `packetmath_13` test
to fail. This disables the test.
Also refactored the existing AVX implementation to use `bit_cast`
instead of direct access to `.x`.
Missing inline breaks blas, since symbol generated in
`complex_single.cpp`, `complex_double.cpp`, `single.cpp`, `double.cpp`
Changed rest of inlines to `EIGEN_STRONG_INLINE`.
Both, Eigen::half and Eigen::Bfloat16 are implicitly convertible to
float and can hence be converted to bool via the conversion chain
Eigen::{half,bfloat16} -> float -> bool
We thus remove the explicit cast operator to bool.
Multiplication of column-major `DynamicSparseMatrix`es involves three
temporaries:
- two for transposing twice to sort the coefficients
(`ConservativeSparseSparseProduct.h`, L160-161)
- one for a final copy assignment (`SparseAssign.h`, L108)
The latter is avoided in an optimization for `SparseMatrix`.
Since `DynamicSparseMatrix` is deprecated in favor of `SparseMatrix`, it's not
worth the effort to optimize further, so I simply disabled counting
temporaries via a macro.
Note that due to the inclusion of `sparse_product.cpp`, the `sparse_extra`
tests actually re-run all the original `sparse_product` tests as well.
We may want to simply drop the `DynamicSparseMatrix` tests altogether, which
would eliminate the test duplication.
Related to #2048
The existing `TensorRandom.h` implementation makes the assumption that
`half` (`bfloat16`) has a `uint16_t` member `x` (`value`), which is not
always true. This currently fails on arm64, where `x` has type `__fp16`.
Added `bit_cast` specializations to allow casting to/from `uint16_t`
for both `half` and `bfloat16`. Also added tests in
`half_float`, `bfloat16_float`, and `cxx11_tensor_random` to catch
these errors in the future.
The `meta` test generates warnings with the latest version of clang due
to passing uninitialized variables as const reference arguments.
```
test/meta.cpp:102:45: error: variable 'f' is uninitialized when passed as a const reference argument here [-Werror,-Wuninitialized-const-reference]
VERIFY(( check_is_convertible(a.dot(b), f) ));
```
We don't actually use the variables, but initializing them eliminates the
new warning.
Fixes#2067.
Note that HTTPS must be used against the MathJax CDN when hosted on `eigen.tuxfamily.org` (which uses HTTPS) in order to avoid `Mixed Content`-errors from browsers. Using HTTPS for MathJax also works if the Eigen docs are hosted on plain HTTP.
When calling `internal::cast<S, std::complex<T>>(x)`, clang often
generates an implicit conversion warning due to an implicit cast
from type `S` to `T`. This currently affects the following tests:
- `basicstuff`
- `bfloat16_float`
- `cxx11_tensor_casts`
The implicit cast leads to widening/narrowing float conversions.
Widening warnings only seem to be generated by clang (`-Wdouble-promotion`).
To eliminate the warning, we explicitly cast the real-component first
from `S` to `T`. We also adjust tests to use `internal::cast` instead
of `static_cast` when a complex type may be involved.
The `OpenGLSupport` module contains mostly deprecated features, and the
test is highly GL context-dependent, relies on deprecated GLUT, and
requires a display. Until the module is updated to support modern
OpenGL and the test to use newer windowing frameworks (e.g. GLFW)
it's probably best to disable the test by default.
The test can be enabled with `cmake -DEIGEN_TEST_OPENGL=ON`.
See #2053 for more details.
