Making them trivially copyable allows using std::memcpy() without undefined
behaviors.
Only Matrix and Array with trivially copyable DenseStorage are marked as
trivially copyable with an additional type trait.
As described in http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0848r3.html
it requires extremely verbose SFINAE to make the special member functions of
fixed-size Matrix and Array trivial, unless C++20 concepts are available to
simplify the selection of trivial special member functions given template
parameters. Therefore only make this feature available to compilers that support
C++20 P0848R3.
Fix#1855.
The following preprocessor macros are added:
- EIGEN_COMP_CPE and EIGEN_COMP_CLANGCPE version number of the CRAY compiler if
Eigen is compiled with the Cray C++ compiler, 0 otherwise.
- EIGEN_COMP_FCC and EIGEN_COMP_CLANGFCC version number of the FCC compiler if
Eigen is compiled with the Fujitsu C++ compiler, 0 otherwise
- EIGEN_COMP_CLANGICC version number of the ICX compiler if Eigen is compiled
with the Intel oneAPI C++ compiler, 0 otherwise
All three compilers (Cray, Fujitsu, Intel) offer a traditional and a Clang-based
frontend. This is distinguished by the CLANG prefix.
Looks like we need to update the
`EIGEN_INHERIT_ASSIGNMENT_EQUAL_OPERATOR` for newer versions of MSVC as
well when compiling with NVCC. Fixes build issues for VS 2017.
CUDA 9 seems to require labelling defaulted constructors as
`EIGEN_DEVICE_FUNC`, despite giving warnings that such labels are
ignored. Without these labels, the `gpu_basic` test fails to
compile, with errors about calling `__host__` functions from
`__host__ __device__` functions.
GCC 4.8 doesn't seem to like the `g` register constraint, failing to
compile with "error: 'asm' operand requires impossible reload".
Tested `r` instead, and that seems to work, even with latest compilers.
Also fixed some minor macro issues to eliminate warnings on armv7.
Fixes#2315.
Details are scattered across #920, #1000, #1324, #2291.
Summary: some MSVC versions have a bug that requires omitting explicit
`operator=` definitions (leads to duplicate definition errors), and
some MSVC versions require adding explicit `operator=` definitions
(otherwise implicitly deleted errors). This mess tries to cover
all the cases encountered.
Fixes#2291.
Some CUDA/HIP constants fail on device with `constexpr` since they
internally rely on non-constexpr functions, e.g.
```
\#define CUDART_INF_F __int_as_float(0x7f800000)
```
This fails for cuda-clang (though passes with nvcc). These constants are
currently used by `device::numeric_limits`. For portability, we
need to remove `constexpr` from the affected functions.
For C++11 or higher, we should be able to rely on the `std::numeric_limits`
versions anyways, since the methods themselves are now `constexpr`, so
should be supported on device (clang/hipcc natively, nvcc with
`--expr-relaxed-constexpr`).
The Eigen unit-tests started failing on the HIP/ROCm platform, after the following commit
e7b8643d70
```
In file included from /home/rocm-user/eigen/test/main.h:360:
In file included from /home/rocm-user/eigen/Eigen/QR:11:
In file included from /home/rocm-user/eigen/Eigen/Core:162:
/home/rocm-user/eigen/Eigen/src/Core/util/Meta.h:300:17: error: constexpr function never produces a constant expression [-Winvalid-constexpr]
static float (max)() {
^
/home/rocm-user/eigen/Eigen/src/Core/util/Meta.h:304:12: note: non-constexpr function '__int_as_float' cannot be used in a constant expression
return HIPRT_MAX_NORMAL_F;
^
/home/rocm-user/eigen/Eigen/src/Core/arch/HIP/hcc/math_constants.h:14:28: note: expanded from macro 'HIPRT_MAX_NORMAL_F'
#define HIPRT_MAX_NORMAL_F __int_as_float(0x7f7fffff)
^
/opt/rocm/hip/include/hip/hcc_detail/device_functions.h:913:32: note: declared here
__device__ static inline float __int_as_float(int x) {
^
```
The problem seems to that some of the constants defined in the HIP `math_constants.h` have a call to `__int_as_float` routine which is not declared `constexpr` in the HIP runtime header file.
Working around this issue for now, be skipping the const_expr support (enabled via the above commit) on HIP
NVCC does not understand `__forceinline`, so we need to use `inline`
when compiling for GPU.
ICC specializes `std::complex` operators for `float` and `double`
by default, which cannot be used on device and conflict with Eigen's
workaround in CUDA/Complex.h. This can be prevented by defining
`_OVERRIDE_COMPLEX_SPECIALIZATION_` before including `<complex>`.
Added this define to the tests and to `Eigen/Core`, but this will
not work if the user includes `<complex>` before `<Eigen/Core>`.
ICC also seems to generate a duplicate `Map` symbol in
`PlainObjectBase`:
```
error: "Map" has already been declared in the current scope
static ConstMapType Map(const Scalar *data)
```
I tracked this down to `friend class Eigen::Map`. Putting the `friend`
statements at the bottom of the class seems to resolve this issue.
Fixes#2180
