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
`g_called` is not used in subtest 7, so was generating a
`-Wunneeded-internal-declaration` warnings. Here we silence
it by initializing the static variable.
The original fails with nvcc+msvc - there's a static order of initialization
issue leading to registered tests being cleared. The test then fails on
```
VERIFY(EigenTest::all().size()>0);
```
since `EigenTest` no longer contains any tests. The singleton pattern
fixes this.
Replace usage of `std::numeric_limits<...>::min/max_exponent` in
codebase where possible. Also replaced some other `numeric_limits`
usages in affected tests with the `NumTraits` equivalent.
The previous MR !443 failed for c++03 due to lack of `constexpr`.
Because of this, we need to keep around the `std::numeric_limits`
version in enum expressions until the switch to c++11.
Fixes#2148
Replace usage of `std::numeric_limits<...>::min/max_exponent` in
codebase. Also replaced some other `numeric_limits` usages in
affected tests with the `NumTraits` equivalent.
Fixes#2148
This is to resolve an issue for large inputs when +0.5 can
actually lead to +1 if the input doesn't have enough precision
to resolve the addition - leading to an off-by-one error.
See discussion on 9a663973.
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
The original swap approach leads to potential undefined behavior (reading
uninitialized memory) and results in unnecessary copying of data for static
storage.
Here we pass down the move assignment to the underlying storage. Static
storage does a one-way copy, dynamic storage does a swap.
Modified the tests to no longer read from the moved-from matrix/tensor,
since that can lead to UB. Added a test to ensure we do not access
uninitialized memory in a move.
Fixes: #2119
Both CUDA and HIP require trivial default constructors for types used
in shared memory. Otherwise failing with
```
error: initialization is not supported for __shared__ variables.
```
Currently, when compiling with HIP, Eigen::half is derived from the `__half_raw` struct that is defined within the hip_fp16.h header file. This is true for both the "host" compile phase and the "device" compile phase. This was causing a very hard to detect bug in the ROCm TensorFlow build.
In the ROCm Tensorflow build,
* files that do not contain ant GPU code get compiled via gcc, and
* files that contnain GPU code get compiled via hipcc.
In certain case, we have a function that is defined in a file that is compiled by hipcc, and is called in a file that is compiled by gcc. If such a function had Eigen::half has a "pass-by-value" argument, its value was getting corrupted, when received by the function.
The reason for this seems to be that for the gcc compile, Eigen::half is derived from a `__half_raw` struct that has `uint16_t` as the data-store, and for hipcc the `__half_raw` implementation uses `_Float16` as the data store. There is some ABI incompatibility between gcc / hipcc (which is essentially latest clang), which results in the Eigen::half value (which is correct at the call-site) getting randomly corrupted when passed to the function.
Changing the Eigen::half argument to be "pass by reference" seems to workaround the error.
In order to fix it such that we do not run into it again in TF, this commit changes the Eigne::half implementation to use the same `__half_raw` implementation as the non-GPU compile, during host compile phase of the hipcc compile.
The macro `__cplusplus` is not defined correctly in MSVC unless building
with the the `/Zc:__cplusplus` flag. Instead, it defines `_MSVC_LANG` to the
specified c++ standard version number.
Here we introduce `EIGEN_CPLUSPLUS` which will contain the c++ version
number both for MSVC and otherwise. This simplifies checks for supported
features.
Also replaced most instances of standard version checking via `__cplusplus`
with the existing `EIGEN_COMP_CXXVER` macro for better clarity.
Fixes: #2170
This is a new version of !423, which failed for MSVC.
Defined `EIGEN_OPTIMIZATION_BARRIER(X)` that uses inline assembly to
prevent operations involving `X` from crossing that barrier. Should
work on most `GNUC` compatible compilers (MSVC doesn't seem to need
this). This is a modified version adapted from what was used in
`psincos_float` and tested on more platforms
(see #1674, https://godbolt.org/z/73ezTG).
Modified `rint` to use the barrier to prevent the add/subtract rounding
trick from being optimized away.
Also fixed an edge case for large inputs that get bumped 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.
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.
