The following commit breaks Eigen for ROCm (and probably CUDA too) with the following error
e265f7ed8e
```
Building HIPCC object test/CMakeFiles/gpu_basic.dir/gpu_basic_generated_gpu_basic.cu.o
In file included from /home/rocm-user/eigen/test/gpu_basic.cu:20:
In file included from /home/rocm-user/eigen/test/main.h:355:
In file included from /home/rocm-user/eigen/Eigen/QR:11:
In file included from /home/rocm-user/eigen/Eigen/Core:169:
/home/rocm-user/eigen/Eigen/src/Core/arch/Default/Half.h:825:76: error: use of undeclared identifier 'numext'; did you mean 'Eigen::numext'?
return Eigen::half_impl::raw_uint16_to_half(__ldg(reinterpret_cast<const numext::uint16_t*>(ptr)));
^~~~~~
Eigen::numext
/home/rocm-user/eigen/Eigen/src/Core/MathFunctions.h:968:11: note: 'Eigen::numext' declared here
namespace numext {
^
1 error generated when compiling for gfx900.
CMake Error at gpu_basic_generated_gpu_basic.cu.o.cmake:192 (message):
Error generating file
/home/rocm-user/eigen/build/test/CMakeFiles/gpu_basic.dir//./gpu_basic_generated_gpu_basic.cu.o
test/CMakeFiles/gpu_basic.dir/build.make:63: recipe for target 'test/CMakeFiles/gpu_basic.dir/gpu_basic_generated_gpu_basic.cu.o' failed
make[3]: *** [test/CMakeFiles/gpu_basic.dir/gpu_basic_generated_gpu_basic.cu.o] Error 1
CMakeFiles/Makefile2:16611: recipe for target 'test/CMakeFiles/gpu_basic.dir/all' failed
make[2]: *** [test/CMakeFiles/gpu_basic.dir/all] Error 2
CMakeFiles/Makefile2:16618: recipe for target 'test/CMakeFiles/gpu_basic.dir/rule' failed
make[1]: *** [test/CMakeFiles/gpu_basic.dir/rule] Error 2
Makefile:5401: recipe for target 'gpu_basic' failed
make: *** [gpu_basic] Error 2
```
The fix is in this commit is trivial. Please review and merge
Armv8.2-a provides a native half-precision floating point (__fp16 aka.
float16_t). This patch introduces
* __fp16 as underlying type of Eigen::half if this type is available
* the packet types Packet4hf and Packet8hf representing float16x4_t and
float16x8_t respectively
* packet-math for the above packets with corresponding scalar type Eigen::half
The packet-math functionality has been implemented by Ashutosh Sharma
<ashutosh.sharma@amperecomputing.com>.
This closes#1940.
The following commit causes regressions in the ROCm/HIP support for Eigen
e55182ac09
I suspect the same breakages occur on the CUDA side too.
The above commit puts the EIGEN_CONSTEXPR attribute on `half_base` constructor. `half_base` is derived from `__half_raw`.
When compiling with GPU support, the definition of `__half_raw` gets picked up from the GPU Compiler specific header files (`hip_fp16.h`, `cuda_fp16.h`). Properly supporting the above commit would require adding the `constexpr` attribute to the `__half_raw` constructor (and other `*half*` routines) in those header files. While that is something we can explore in the future, for now we need to undo the above commit when compiling with GPU support, which is what this commit does.
This commit also reverts a small change in the `raw_uint16_to_half` routine made by the above commit. Similar to the case above, that change was leading to compile errors due to the fact that `__half_raw` has a different definition when compiling with DPU support.
CastXML simulates the preprocessors of other compilers, but actually
parses the translation unit with an internal Clang compiler.
Use the same `vld1q_u64` workaround that we do for Clang.
Fixes: #1979
The NEON implementation mimics the SSE implementation, but didn't mention the caveat that due to the unsigned of signed integer conversions, not all values in the original floating point represented are supported.
If we have explicit conversion operators available (C++11) we define
explicit casts from bfloat16 to other types. If not (C++03), we don't
define conversion operators but rely on implicit conversion chains from
bfloat16 over float to other types.
