root/python_bindings/numpy/dtype.cpp

DEFINITIONS

1. get
2. get_int_dtype
3. get_float_dtype
4. get_complex_dtype
5. get
6. get
7. convert
8. get_itemsize
9. equivalent
10. get_pytype
11. convertible
12. convert
13. declare
14. register_scalar_converters

// Copyright Jim Bosch 2010-2012.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)
#ifdef _MSC_VER
#include <boost/cstdint.hpp>
#endif
#define HALIDE_NUMPY_INTERNAL
#include "internal.hpp"

#define DTYPE_FROM_CODE(code) \
    dtype(python::detail::new_reference(reinterpret_cast<PyObject *>(PyArray_DescrFromType(code))))

#define BUILTIN_INT_DTYPE(bits)                                        \
    template <>                                                        \
    struct builtin_int_dtype<bits, false> {                            \
        static dtype get() { return DTYPE_FROM_CODE(NPY_INT##bits); }  \
    };                                                                 \
    template <>                                                        \
    struct builtin_int_dtype<bits, true> {                             \
        static dtype get() { return DTYPE_FROM_CODE(NPY_UINT##bits); } \
    };                                                                 \
    template dtype get_int_dtype<bits, false>();                       \
    template dtype get_int_dtype<bits, true>()

#define BUILTIN_FLOAT_DTYPE(bits)                                       \
    template <>                                                         \
    struct builtin_float_dtype<bits> {                                  \
        static dtype get() { return DTYPE_FROM_CODE(NPY_FLOAT##bits); } \
    };                                                                  \
    template dtype get_float_dtype<bits>()

#define BUILTIN_COMPLEX_DTYPE(bits)                                       \
    template <>                                                           \
    struct builtin_complex_dtype<bits> {                                  \
        static dtype get() { return DTYPE_FROM_CODE(NPY_COMPLEX##bits); } \
    };                                                                    \
    template dtype get_complex_dtype<bits>()

namespace boost {
namespace python {
namespace converter {
NUMPY_OBJECT_MANAGER_TRAITS_IMPL(PyArrayDescr_Type, Halide::numpy::dtype)
}
}
}  // namespace boost::python::converter

namespace Halide {
namespace numpy {

namespace detail {

dtype builtin_dtype<bool, true>::get() { return DTYPE_FROM_CODE(NPY_BOOL); }

template <int bits, bool isUnsigned>
struct builtin_int_dtype;
template <int bits>
struct builtin_float_dtype;
template <int bits>
struct builtin_complex_dtype;

template <int bits, bool isUnsigned>
dtype get_int_dtype() {
    return builtin_int_dtype<bits, isUnsigned>::get();
}
template <int bits>
dtype get_float_dtype() { return builtin_float_dtype<bits>::get(); }
template <int bits>
dtype get_complex_dtype() { return builtin_complex_dtype<bits>::get(); }

BUILTIN_INT_DTYPE(8);
BUILTIN_INT_DTYPE(16);
BUILTIN_INT_DTYPE(32);
BUILTIN_INT_DTYPE(64);
BUILTIN_FLOAT_DTYPE(16);
BUILTIN_FLOAT_DTYPE(32);
BUILTIN_FLOAT_DTYPE(64);
BUILTIN_COMPLEX_DTYPE(64);
BUILTIN_COMPLEX_DTYPE(128);
#if NPY_BITSOF_LONGDOUBLE > NPY_BITSOF_DOUBLE
template <>
struct builtin_float_dtype<NPY_BITSOF_LONGDOUBLE> {
    static dtype get() { return DTYPE_FROM_CODE(NPY_LONGDOUBLE); }
};
template dtype get_float_dtype<NPY_BITSOF_LONGDOUBLE>();
template <>
struct builtin_complex_dtype<2 * NPY_BITSOF_LONGDOUBLE> {
    static dtype get() { return DTYPE_FROM_CODE(NPY_CLONGDOUBLE); }
};
template dtype get_complex_dtype<2 * NPY_BITSOF_LONGDOUBLE>();
#endif

}  // namespace detail

python::detail::new_reference dtype::convert(python::object const &arg, bool align) {
    PyArray_Descr *obj = NULL;
    if (align) {
        if (PyArray_DescrAlignConverter(arg.ptr(), &obj) < 0)
            python::throw_error_already_set();
    } else {
        if (PyArray_DescrConverter(arg.ptr(), &obj) < 0)
            python::throw_error_already_set();
    }
    return python::detail::new_reference(reinterpret_cast<PyObject *>(obj));
}

int dtype::get_itemsize() const { return reinterpret_cast<PyArray_Descr *>(ptr())->elsize; }

bool equivalent(dtype const &a, dtype const &b) {
// On Windows x64, the behaviour described on
// http://docs.scipy.org/doc/numpy/reference/c-api.array.html for
// PyArray_EquivTypes unfortunately does not extend as expected:
// "For example, on 32-bit platforms, NPY_LONG and NPY_INT are equivalent".
// This should also hold for 64-bit platforms (and does on Linux), but not
// on Windows. Implement an alternative:
#ifdef _MSC_VER
    if (sizeof(long) == sizeof(int) &&
        // Manually take care of the type equivalence.
        ((a == dtype::get_builtin<long>() || a == dtype::get_builtin<int>()) &&
             (b == dtype::get_builtin<long>() || b == dtype::get_builtin<int>()) ||
         (a == dtype::get_builtin<unsigned int>() || a == dtype::get_builtin<unsigned long>()) &&
             (b == dtype::get_builtin<unsigned int>() || b == dtype::get_builtin<unsigned long>()))) {
        return true;
    } else {
        return PyArray_EquivTypes(
            reinterpret_cast<PyArray_Descr *>(a.ptr()),
            reinterpret_cast<PyArray_Descr *>(b.ptr()));
    }
#else
    return PyArray_EquivTypes(
        reinterpret_cast<PyArray_Descr *>(a.ptr()),
        reinterpret_cast<PyArray_Descr *>(b.ptr()));
#endif
}

namespace {

namespace pyconv = boost::python::converter;

template <typename T>
class array_scalar_converter {
public:
    static PyTypeObject const *get_pytype() {
        // This implementation depends on the fact that get_builtin returns pointers to objects
        // NumPy has declared statically, and that the typeobj member also refers to a static
        // object.  That means we don't need to do any reference counting.
        // In fact, I'm somewhat concerned that increasing the reference count of any of these
        // might cause leaks, because I don't think Boost.Python ever decrements it, but it's
        // probably a moot point if everything is actually static.
        return reinterpret_cast<PyArray_Descr *>(dtype::get_builtin<T>().ptr())->typeobj;
    }

    static void *convertible(PyObject *obj) {
        if (obj->ob_type == get_pytype()) {
            return obj;
        } else {
            dtype dt(python::detail::borrowed_reference(obj->ob_type));
            if (equivalent(dt, dtype::get_builtin<T>())) {
                return obj;
            }
        }
        return 0;
    }

    static void convert(PyObject *obj, pyconv::rvalue_from_python_stage1_data *data) {
        void *storage = reinterpret_cast<pyconv::rvalue_from_python_storage<T> *>(data)->storage.bytes;
        // We assume std::complex is a "standard layout" here and elsewhere; not guaranteed by
        // C++03 standard, but true in every known implementation (and guaranteed by C++11).
        PyArray_ScalarAsCtype(obj, reinterpret_cast<T *>(storage));
        data->convertible = storage;
    }

    static void declare() {
        pyconv::registry::push_back(
            &convertible, &convert, python::type_id<T>()
#ifndef BOOST_PYTHON_NO_PY_SIGNATURES
                                        ,
            &get_pytype
#endif
            );
    }
};

}  // anonymous

void dtype::register_scalar_converters() {
    array_scalar_converter<bool>::declare();
    array_scalar_converter<npy_uint8>::declare();
    array_scalar_converter<npy_int8>::declare();
    array_scalar_converter<npy_uint16>::declare();
    array_scalar_converter<npy_int16>::declare();
    array_scalar_converter<npy_uint32>::declare();
    array_scalar_converter<npy_int32>::declare();
#ifdef _MSC_VER
    // Since the npy_(u)int32 types are defined as long types and treated
    // as being different from the int32 types, these converters must be declared
    // explicitely.
    array_scalar_converter<boost::uint32_t>::declare();
    array_scalar_converter<boost::int32_t>::declare();
#endif
    array_scalar_converter<npy_uint64>::declare();
    array_scalar_converter<npy_int64>::declare();
    array_scalar_converter<float>::declare();
    array_scalar_converter<double>::declare();
    array_scalar_converter<std::complex<float>>::declare();
    array_scalar_converter<std::complex<double>>::declare();
#if NPY_BITSOF_LONGDOUBLE > NPY_BITSOF_DOUBLE
    array_scalar_converter<long double>::declare();
    array_scalar_converter<std::complex<long double>>::declare();
#endif
}

}  // namespace Halide::numpy
}  // namespace Halide