Add CUDA complex sqrt.

This is to support scalar `sqrt` of complex numbers `std::complex<T>` on
device, requested by Tensorflow folks.

Technically `std::complex` is not supported by NVCC on device
(though it is by clang), so the default `sqrt(std::complex<T>)` function only
works on the host. Here we create an overload to add back the
functionality.

Also modified the CMake file to add `--relaxed-constexpr` (or
equivalent) flag for NVCC to allow calling constexpr functions from
device functions, and added support for specifying compute architecture for
NVCC (was already available for clang).
This commit is contained in:
Antonio Sanchez 2020-12-22 22:49:06 -08:00
parent fdf2ee62c5
commit 070d303d56
7 changed files with 217 additions and 28 deletions

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@ -323,6 +323,27 @@ struct abs2_retval
typedef typename NumTraits<Scalar>::Real type;
};
/****************************************************************************
* Implementation of sqrt *
****************************************************************************/
template<typename Scalar>
struct sqrt_impl
{
EIGEN_DEVICE_FUNC
static EIGEN_ALWAYS_INLINE Scalar run(const Scalar& x)
{
EIGEN_USING_STD(sqrt);
return sqrt(x);
}
};
template<typename Scalar>
struct sqrt_retval
{
typedef Scalar type;
};
/****************************************************************************
* Implementation of norm1 *
****************************************************************************/
@ -1368,12 +1389,11 @@ inline int log2(int x)
*
* It's usage is justified in performance critical functions, like norm/normalize.
*/
template<typename T>
EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
T sqrt(const T &x)
template<typename Scalar>
EIGEN_DEVICE_FUNC
EIGEN_ALWAYS_INLINE EIGEN_MATHFUNC_RETVAL(sqrt, Scalar) sqrt(const Scalar& x)
{
EIGEN_USING_STD(sqrt);
return sqrt(x);
return EIGEN_MATHFUNC_IMPL(sqrt, Scalar)::run(x);
}
// Boolean specialization, avoids implicit float to bool conversion (-Wimplicit-conversion-floating-point-to-bool).

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@ -12,12 +12,12 @@
// clang-format off
#if defined(EIGEN_CUDACC) && defined(EIGEN_GPU_COMPILE_PHASE)
namespace Eigen {
namespace internal {
#if defined(EIGEN_CUDACC) && defined(EIGEN_USE_GPU)
// Many std::complex methods such as operator+, operator-, operator* and
// operator/ are not constexpr. Due to this, clang does not treat them as device
// functions and thus Eigen functors making use of these operators fail to
@ -94,10 +94,53 @@ template<typename T> struct scalar_quotient_op<const std::complex<T>, const std:
template<typename T> struct scalar_quotient_op<std::complex<T>, std::complex<T> > : scalar_quotient_op<const std::complex<T>, const std::complex<T> > {};
template<typename T>
struct sqrt_impl<std::complex<T>> {
static EIGEN_DEVICE_FUNC std::complex<T> run(const std::complex<T>& z) {
// Computes the principal sqrt of the input.
//
// For a complex square root of the number x + i*y. We want to find real
// numbers u and v such that
// (u + i*v)^2 = x + i*y <=>
// u^2 - v^2 + i*2*u*v = x + i*v.
// By equating the real and imaginary parts we get:
// u^2 - v^2 = x
// 2*u*v = y.
//
// For x >= 0, this has the numerically stable solution
// u = sqrt(0.5 * (x + sqrt(x^2 + y^2)))
// v = y / (2 * u)
// and for x < 0,
// v = sign(y) * sqrt(0.5 * (-x + sqrt(x^2 + y^2)))
// u = y / (2 * v)
//
// Letting w = sqrt(0.5 * (|x| + |z|)),
// if x == 0: u = w, v = sign(y) * w
// if x > 0: u = w, v = y / (2 * w)
// if x < 0: u = |y| / (2 * w), v = sign(y) * w
const T x = numext::real(z);
const T y = numext::imag(z);
const T zero = T(0);
const T cst_half = T(0.5);
// Special case of isinf(y)
if ((numext::isinf)(y)) {
const T inf = std::numeric_limits<T>::infinity();
return std::complex<T>(inf, y);
}
T w = numext::sqrt(cst_half * (numext::abs(x) + numext::abs(z)));
return
x == zero ? std::complex<T>(w, y < zero ? -w : w)
: x > zero ? std::complex<T>(w, y / (2 * w))
: std::complex<T>(numext::abs(y) / (2 * w), y < zero ? -w : w );
}
};
} // namespace internal
} // namespace Eigen
#endif
} // end namespace internal
} // end namespace Eigen
#endif // EIGEN_COMPLEX_CUDA_H
#endif // EIGEN_COMPLEX_CUDA_H

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@ -703,8 +703,8 @@ Packet psqrt_complex(const Packet& a) {
// u = sqrt(0.5 * (x + sqrt(x^2 + y^2)))
// v = 0.5 * (y / u)
// and for x < 0,
// v = sign(y) * sqrt(0.5 * (x + sqrt(x^2 + y^2)))
// u = |0.5 * (y / v)|
// v = sign(y) * sqrt(0.5 * (-x + sqrt(x^2 + y^2)))
// u = 0.5 * (y / v)
//
// To avoid unnecessary over- and underflow, we compute sqrt(x^2 + y^2) as
// l = max(|x|, |y|) * sqrt(1 + (min(|x|, |y|) / max(|x|, |y|))^2) ,

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@ -395,6 +395,12 @@ find_package(CUDA 5.0)
if(CUDA_FOUND)
set(CUDA_PROPAGATE_HOST_FLAGS OFF)
set(EIGEN_CUDA_RELAXED_CONSTEXPR "--expt-relaxed-constexpr")
if (${CUDA_VERSION} STREQUAL "7.0")
set(EIGEN_CUDA_RELAXED_CONSTEXPR "--relaxed-constexpr")
endif()
if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
set(CUDA_NVCC_FLAGS "-ccbin ${CMAKE_C_COMPILER}" CACHE STRING "nvcc flags" FORCE)
endif()
@ -404,7 +410,12 @@ if(CUDA_FOUND)
foreach(GPU IN LISTS EIGEN_CUDA_COMPUTE_ARCH)
string(APPEND CMAKE_CXX_FLAGS " --cuda-gpu-arch=sm_${GPU}")
endforeach()
else()
foreach(GPU IN LISTS EIGEN_CUDA_COMPUTE_ARCH)
string(APPEND CUDA_NVCC_FLAGS " -gencode arch=compute_${GPU},code=sm_${GPU}")
endforeach()
endif()
string(APPEND CUDA_NVCC_FLAGS " ${EIGEN_CUDA_RELAXED_CONSTEXPR}")
set(EIGEN_ADD_TEST_FILENAME_EXTENSION "cu")
ei_add_test(gpu_basic)

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@ -14,7 +14,6 @@
#endif
#define EIGEN_TEST_NO_LONGDOUBLE
#define EIGEN_TEST_NO_COMPLEX
#define EIGEN_DEFAULT_DENSE_INDEX_TYPE int
#include "main.h"
@ -54,6 +53,59 @@ struct coeff_wise {
}
};
template<typename T>
struct complex_sqrt {
EIGEN_DEVICE_FUNC
void operator()(int i, const typename T::Scalar* in, typename T::Scalar* out) const
{
using namespace Eigen;
typedef typename T::Scalar ComplexType;
typedef typename T::Scalar::value_type ValueType;
const int num_special_inputs = 18;
if (i == 0) {
const ValueType nan = std::numeric_limits<ValueType>::quiet_NaN();
typedef Eigen::Vector<ComplexType, num_special_inputs> SpecialInputs;
SpecialInputs special_in;
special_in.setZero();
int idx = 0;
special_in[idx++] = ComplexType(0, 0);
special_in[idx++] = ComplexType(-0, 0);
special_in[idx++] = ComplexType(0, -0);
special_in[idx++] = ComplexType(-0, -0);
// GCC's fallback sqrt implementation fails for inf inputs.
// It is called when _GLIBCXX_USE_C99_COMPLEX is false or if
// clang includes the GCC header (which temporarily disables
// _GLIBCXX_USE_C99_COMPLEX)
#if !defined(_GLIBCXX_COMPLEX) || \
(_GLIBCXX_USE_C99_COMPLEX && !defined(__CLANG_CUDA_WRAPPERS_COMPLEX))
const ValueType inf = std::numeric_limits<ValueType>::infinity();
special_in[idx++] = ComplexType(1.0, inf);
special_in[idx++] = ComplexType(nan, inf);
special_in[idx++] = ComplexType(1.0, -inf);
special_in[idx++] = ComplexType(nan, -inf);
special_in[idx++] = ComplexType(-inf, 1.0);
special_in[idx++] = ComplexType(inf, 1.0);
special_in[idx++] = ComplexType(-inf, -1.0);
special_in[idx++] = ComplexType(inf, -1.0);
special_in[idx++] = ComplexType(-inf, nan);
special_in[idx++] = ComplexType(inf, nan);
#endif
special_in[idx++] = ComplexType(1.0, nan);
special_in[idx++] = ComplexType(nan, 1.0);
special_in[idx++] = ComplexType(nan, -1.0);
special_in[idx++] = ComplexType(nan, nan);
Map<SpecialInputs> special_out(out);
special_out = special_in.cwiseSqrt();
}
T x1(in + i);
Map<T> res(out + num_special_inputs + i*T::MaxSizeAtCompileTime);
res = x1.cwiseSqrt();
}
};
template<typename T>
struct replicate {
EIGEN_DEVICE_FUNC
@ -161,17 +213,58 @@ struct matrix_inverse {
}
};
template<typename Type1, typename Type2>
bool verifyIsApproxWithInfsNans(const Type1& a, const Type2& b, typename Type1::Scalar* = 0) // Enabled for Eigen's type only
{
if (a.rows() != b.rows()) {
return false;
}
if (a.cols() != b.cols()) {
return false;
}
for (Index r = 0; r < a.rows(); ++r) {
for (Index c = 0; c < a.cols(); ++c) {
if (a(r, c) != b(r, c)
&& !((numext::isnan)(a(r, c)) && (numext::isnan)(b(r, c)))
&& !test_isApprox(a(r, c), b(r, c))) {
return false;
}
}
}
return true;
}
template<typename Kernel, typename Input, typename Output>
void test_with_infs_nans(const Kernel& ker, int n, const Input& in, Output& out)
{
Output out_ref, out_gpu;
#if !defined(EIGEN_GPU_COMPILE_PHASE)
out_ref = out_gpu = out;
#else
EIGEN_UNUSED_VARIABLE(in);
EIGEN_UNUSED_VARIABLE(out);
#endif
run_on_cpu (ker, n, in, out_ref);
run_on_gpu(ker, n, in, out_gpu);
#if !defined(EIGEN_GPU_COMPILE_PHASE)
verifyIsApproxWithInfsNans(out_ref, out_gpu);
#endif
}
EIGEN_DECLARE_TEST(gpu_basic)
{
ei_test_init_gpu();
int nthreads = 100;
Eigen::VectorXf in, out;
Eigen::VectorXcf cfin, cfout;
#if !defined(__CUDA_ARCH__) && !defined(__HIP_DEVICE_COMPILE__)
#if !defined(EIGEN_GPU_COMPILE_PHASE)
int data_size = nthreads * 512;
in.setRandom(data_size);
out.setRandom(data_size);
out.setConstant(data_size, -1);
cfin.setRandom(data_size);
cfout.setConstant(data_size, -1);
#endif
CALL_SUBTEST( run_and_compare_to_gpu(coeff_wise<Vector3f>(), nthreads, in, out) );
@ -204,6 +297,8 @@ EIGEN_DECLARE_TEST(gpu_basic)
CALL_SUBTEST( run_and_compare_to_gpu(eigenvalues_direct<Matrix3f>(), nthreads, in, out) );
CALL_SUBTEST( run_and_compare_to_gpu(eigenvalues_direct<Matrix2f>(), nthreads, in, out) );
CALL_SUBTEST( test_with_infs_nans(complex_sqrt<Vector3cf>(), nthreads, cfin, cfout) );
#if defined(__NVCC__)
// FIXME
// These subtests compiles only with nvcc and fail with HIPCC and clang-cuda

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@ -68,8 +68,20 @@ void run_on_gpu(const Kernel& ker, int n, const Input& in, Output& out)
#else
run_on_gpu_meta_kernel<<<Grids,Blocks>>>(ker, n, d_in, d_out);
#endif
// Pre-launch errors.
gpuError_t err = gpuGetLastError();
if (err != gpuSuccess) {
printf("%s: %s\n", gpuGetErrorName(err), gpuGetErrorString(err));
gpu_assert(false);
}
// Kernel execution errors.
err = gpuDeviceSynchronize();
if (err != gpuSuccess) {
printf("%s: %s\n", gpuGetErrorName(err), gpuGetErrorString(err));
gpu_assert(false);
}
gpuDeviceSynchronize();
// check inputs have not been modified
gpuMemcpy(const_cast<typename Input::Scalar*>(in.data()), d_in, in_bytes, gpuMemcpyDeviceToHost);
@ -85,7 +97,7 @@ void run_and_compare_to_gpu(const Kernel& ker, int n, const Input& in, Output& o
{
Input in_ref, in_gpu;
Output out_ref, out_gpu;
#if !defined(__CUDA_ARCH__) && !defined(__HIP_DEVICE_COMPILE__)
#if !defined(EIGEN_GPU_COMPILE_PHASE)
in_ref = in_gpu = in;
out_ref = out_gpu = out;
#else
@ -94,7 +106,7 @@ void run_and_compare_to_gpu(const Kernel& ker, int n, const Input& in, Output& o
#endif
run_on_cpu (ker, n, in_ref, out_ref);
run_on_gpu(ker, n, in_gpu, out_gpu);
#if !defined(__CUDA_ARCH__) && !defined(__HIP_DEVICE_COMPILE__)
#if !defined(EIGEN_GPU_COMPILE_PHASE)
VERIFY_IS_APPROX(in_ref, in_gpu);
VERIFY_IS_APPROX(out_ref, out_gpu);
#endif
@ -102,14 +114,16 @@ void run_and_compare_to_gpu(const Kernel& ker, int n, const Input& in, Output& o
struct compile_time_device_info {
EIGEN_DEVICE_FUNC
void operator()(int /*i*/, const int* /*in*/, int* info) const
void operator()(int i, const int* /*in*/, int* info) const
{
#if defined(__CUDA_ARCH__)
info[0] = int(__CUDA_ARCH__ +0);
#endif
#if defined(EIGEN_HIP_DEVICE_COMPILE)
info[1] = int(EIGEN_HIP_DEVICE_COMPILE +0);
#endif
if (i == 0) {
#if defined(__CUDA_ARCH__)
info[0] = int(__CUDA_ARCH__ +0);
#endif
#if defined(EIGEN_HIP_DEVICE_COMPILE)
info[1] = int(EIGEN_HIP_DEVICE_COMPILE +0);
#endif
}
}
};

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@ -16,7 +16,7 @@
// for some reason gets sent to the gcc/host compiler instead of the gpu/nvcc/hipcc compiler
// When compiling such files, gcc will end up trying to pick up the CUDA headers by
// default (see the code within "unsupported/Eigen/CXX11/Tensor" that is guarded by EIGEN_USE_GPU)
// This will obsviously not work when trying to compile tensorflow on a system with no CUDA
// This will obviously not work when trying to compile tensorflow on a system with no CUDA
// To work around this issue for HIP systems (and leave the default behaviour intact), the
// HIP tensorflow build defines EIGEN_USE_HIP when compiling all source files, and
// "unsupported/Eigen/CXX11/Tensor" has been updated to use HIP header when EIGEN_USE_HIP is
@ -30,6 +30,9 @@
#define gpuSuccess hipSuccess
#define gpuErrorNotReady hipErrorNotReady
#define gpuGetDeviceCount hipGetDeviceCount
#define gpuGetLastError hipGetLastError
#define gpuPeekAtLastError hipPeekAtLastError
#define gpuGetErrorName hipGetErrorName
#define gpuGetErrorString hipGetErrorString
#define gpuGetDeviceProperties hipGetDeviceProperties
#define gpuStreamDefault hipStreamDefault
@ -57,6 +60,9 @@
#define gpuSuccess cudaSuccess
#define gpuErrorNotReady cudaErrorNotReady
#define gpuGetDeviceCount cudaGetDeviceCount
#define gpuGetLastError cudaGetLastError
#define gpuPeekAtLastError cudaPeekAtLastError
#define gpuGetErrorName cudaGetErrorName
#define gpuGetErrorString cudaGetErrorString
#define gpuGetDeviceProperties cudaGetDeviceProperties
#define gpuStreamDefault cudaStreamDefault