NPY_NO_EXPORT int
_IsAligned(PyArrayObject *ap)
{
unsigned int i, aligned = 1;
const unsigned int alignment = PyArray_DESCR(ap)->alignment;
/* The special casing for STRING and VOID types was removed
* in accordance with http://projects.scipy.org/numpy/ticket/1227
* It used to be that IsAligned always returned True for these
* types, which is indeed the case when they are created using
* PyArray_DescrConverter(), but not necessarily when using
* PyArray_DescrAlignConverter(). */
if (alignment == 1) {
return 1;
}
aligned = npy_is_aligned(PyArray_DATA(ap), alignment);
for (i = 0; i < PyArray_NDIM(ap); i++) {
#if NPY_RELAXED_STRIDES_CHECKING
if (PyArray_DIM(ap, i) > 1) {
/* if shape[i] == 1, the stride is never used */
aligned &= npy_is_aligned((void*)PyArray_STRIDES(ap)[i],
alignment);
}
else if (PyArray_DIM(ap, i) == 0) {
/* an array with zero elements is always aligned */
return 1;
}
#else /* not NPY_RELAXED_STRIDES_CHECKING */
aligned &= npy_is_aligned((void*)PyArray_STRIDES(ap)[i], alignment);
#endif /* not NPY_RELAXED_STRIDES_CHECKING */
}
return aligned != 0;
}
NPY_NO_EXPORT int
_IsAligned(PyArrayObject *ap)
{
unsigned int i;
npy_uintp aligned;
npy_uintp alignment = PyArray_DESCR(ap)->alignment;
/* alignment 1 types should have a efficient alignment for copy loops */
if (PyArray_ISFLEXIBLE(ap) || PyArray_ISSTRING(ap)) {
alignment = 16;
}
if (alignment == 1) {
return 1;
}
aligned = (npy_uintp)PyArray_DATA(ap);
for (i = 0; i < PyArray_NDIM(ap); i++) {
#if NPY_RELAXED_STRIDES_CHECKING
/* skip dim == 1 as it is not required to have stride 0 */
if (PyArray_DIM(ap, i) > 1) {
/* if shape[i] == 1, the stride is never used */
aligned |= (npy_uintp)PyArray_STRIDES(ap)[i];
}
else if (PyArray_DIM(ap, i) == 0) {
/* an array with zero elements is always aligned */
return 1;
}
#else /* not NPY_RELAXED_STRIDES_CHECKING */
aligned |= (npy_uintp)PyArray_STRIDES(ap)[i];
#endif /* not NPY_RELAXED_STRIDES_CHECKING */
}
return npy_is_aligned((void *)aligned, alignment);
}
/*
* Assigns the scalar value to every element of the destination raw array.
*
* Returns 0 on success, -1 on failure.
*/
NPY_NO_EXPORT int
raw_array_assign_scalar(int ndim, npy_intp *shape,
PyArray_Descr *dst_dtype, char *dst_data, npy_intp *dst_strides,
PyArray_Descr *src_dtype, char *src_data)
{
int idim;
npy_intp shape_it[NPY_MAXDIMS], dst_strides_it[NPY_MAXDIMS];
npy_intp coord[NPY_MAXDIMS];
PyArray_StridedUnaryOp *stransfer = NULL;
NpyAuxData *transferdata = NULL;
int aligned, needs_api = 0;
npy_intp src_itemsize = src_dtype->elsize;
NPY_BEGIN_THREADS_DEF;
/* Check alignment */
aligned = raw_array_is_aligned(ndim, dst_data, dst_strides,
dst_dtype->alignment);
if (!npy_is_aligned(src_data, src_dtype->alignment)) {
aligned = 0;
}
/* Use raw iteration with no heap allocation */
if (PyArray_PrepareOneRawArrayIter(
ndim, shape,
dst_data, dst_strides,
&ndim, shape_it,
&dst_data, dst_strides_it) < 0) {
return -1;
}
/* Get the function to do the casting */
if (PyArray_GetDTypeTransferFunction(aligned,
0, dst_strides_it[0],
src_dtype, dst_dtype,
0,
&stransfer, &transferdata,
&needs_api) != NPY_SUCCEED) {
return -1;
}
if (!needs_api) {
npy_intp nitems = 1, i;
for (i = 0; i < ndim; i++) {
nitems *= shape_it[i];
}
NPY_BEGIN_THREADS_THRESHOLDED(nitems);
}
NPY_RAW_ITER_START(idim, ndim, coord, shape_it) {
/* Process the innermost dimension */
stransfer(dst_data, dst_strides_it[0], src_data, 0,
shape_it[0], src_itemsize, transferdata);
} NPY_RAW_ITER_ONE_NEXT(idim, ndim, coord,
/* See array_assign.h for parameter documentation */
NPY_NO_EXPORT int
raw_array_is_aligned(int ndim, npy_intp *shape,
char *data, npy_intp *strides, int alignment)
{
/*
* The code below expects the following:
* * that alignment is a power of two, as required by the C standard.
* * that casting from pointer to uintp gives a sensible representation
* we can use bitwise operations on (perhaps *not* req. by C std,
* but assumed by glibc so it should be fine)
* * that casting stride from intp to uintp (to avoid dependence on the
* signed int representation) preserves remainder wrt alignment, so
* stride%a is the same as ((unsigned intp)stride)%a. Req. by C std.
*
* The code checks whether the lowest log2(alignment) bits of `data`
* and all `strides` are 0, as this implies that
* (data + n*stride)%alignment == 0 for all integers n.
*/
if (alignment > 1) {
npy_uintp align_check = (npy_uintp)data;
int i;
for (i = 0; i < ndim; i++) {
#if NPY_RELAXED_STRIDES_CHECKING
/* skip dim == 1 as it is not required to have stride 0 */
if (shape[i] > 1) {
/* if shape[i] == 1, the stride is never used */
align_check |= (npy_uintp)strides[i];
}
else if (shape[i] == 0) {
/* an array with zero elements is always aligned */
return 1;
}
#else /* not NPY_RELAXED_STRIDES_CHECKING */
align_check |= (npy_uintp)strides[i];
#endif /* not NPY_RELAXED_STRIDES_CHECKING */
}
return npy_is_aligned((void *)align_check, alignment);
}
else if (alignment == 1) {
return 1;
}
else {
/* always return false for alignment == 0, which means cannot-be-aligned */
return 0;
}
}
NPY_NO_EXPORT int
_IsAligned(PyArrayObject *ap)
{
unsigned int i;
npy_uintp aligned;
npy_uintp alignment = PyArray_DESCR(ap)->alignment;
/* alignment 1 types should have a efficient alignment for copy loops */
if (PyArray_ISFLEXIBLE(ap) || PyArray_ISSTRING(ap)) {
npy_intp itemsize = PyArray_ITEMSIZE(ap);
/* power of two sizes may be loaded in larger moves */
if (((itemsize & (itemsize - 1)) == 0)) {
alignment = itemsize > NPY_MAX_COPY_ALIGNMENT ?
NPY_MAX_COPY_ALIGNMENT : itemsize;
}
else {
/* if not power of two it will be accessed bytewise */
alignment = 1;
}
}
if (alignment == 1) {
return 1;
}
aligned = (npy_uintp)PyArray_DATA(ap);
for (i = 0; i < PyArray_NDIM(ap); i++) {
#if NPY_RELAXED_STRIDES_CHECKING
/* skip dim == 1 as it is not required to have stride 0 */
if (PyArray_DIM(ap, i) > 1) {
/* if shape[i] == 1, the stride is never used */
aligned |= (npy_uintp)PyArray_STRIDES(ap)[i];
}
else if (PyArray_DIM(ap, i) == 0) {
/* an array with zero elements is always aligned */
return 1;
}
#else /* not NPY_RELAXED_STRIDES_CHECKING */
aligned |= (npy_uintp)PyArray_STRIDES(ap)[i];
#endif /* not NPY_RELAXED_STRIDES_CHECKING */
}
return npy_is_aligned((void *)aligned, alignment);
}
