diff options
| -rw-r--r-- | numpy/core/src/multiarray/descriptor.c | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/numpy/core/src/multiarray/descriptor.c b/numpy/core/src/multiarray/descriptor.c index c611a1402..d1de37dcd 100644 --- a/numpy/core/src/multiarray/descriptor.c +++ b/numpy/core/src/multiarray/descriptor.c @@ -17,6 +17,18 @@ #include "common.h" #include "descriptor.h" +/* + * offset: A starting offset. + * alignment: A power-of-two alignment. + * + * This macro returns the smallest value >= 'offset' + * which is divisible by 'alignment'. Because 'alignment' + * is a power of two, and integers are twos-complement, + * can use some simple bit-fiddling to do this. + */ +#define NPY_NEXT_ALIGNED_OFFSET(offset, alignment) \ + (((offset) + (alignment) - 1) & (-(alignment))) + static PyObject *typeDict = NULL; /* Must be explicitly loaded */ static PyArray_Descr * @@ -408,8 +420,7 @@ _convert_from_array_descr(PyObject *obj, int align) _align = conv->alignment; if (_align > 1) { - /* The alignment is always a power of 2, so this works */ - totalsize = (totalsize + _align - 1) & (-_align); + totalsize = NPY_NEXT_ALIGNED_OFFSET(totalsize, _align); } maxalign = MAX(maxalign, _align); } @@ -444,8 +455,7 @@ _convert_from_array_descr(PyObject *obj, int align) } if (maxalign > 1) { - /* The alignment is always a power of 2, so this works */ - totalsize = (totalsize + maxalign - 1) & (-maxalign); + totalsize = NPY_NEXT_ALIGNED_OFFSET(totalsize, maxalign); } new = PyArray_DescrNewFromType(PyArray_VOID); @@ -532,8 +542,7 @@ _convert_from_list(PyObject *obj, int align) _align = conv->alignment; if (_align > 1) { - /* The alignment is always a power of 2, so this works */ - totalsize = (totalsize + _align - 1) & (-_align); + totalsize = NPY_NEXT_ALIGNED_OFFSET(totalsize, _align); } maxalign = MAX(maxalign, _align); } @@ -548,8 +557,7 @@ _convert_from_list(PyObject *obj, int align) new->names = nameslist; new->flags = dtypeflags; if (maxalign > 1) { - /* The alignment is always a power of 2, so this works */ - totalsize = (totalsize + maxalign - 1) & (-maxalign); + totalsize = NPY_NEXT_ALIGNED_OFFSET(totalsize, maxalign); } /* Structured arrays get a sticky aligned bit */ if (align) { @@ -706,7 +714,6 @@ validate_object_field_overlap(PyArray_Descr *dtype) Py_ssize_t i, j, names_size; PyArray_Descr *fld_dtype, *fld2_dtype; int fld_offset, fld2_offset, align; - npy_intp total_offset; /* Get some properties from the dtype */ names = dtype->names; @@ -916,8 +923,7 @@ _convert_from_dict(PyObject *obj, int align) } else { if (align && _align > 1) { - /* The alignment is always a power of 2, so this works */ - totalsize = (totalsize + _align - 1) & (-_align); + totalsize = NPY_NEXT_ALIGNED_OFFSET(totalsize, _align); } PyTuple_SET_ITEM(tup, 1, PyInt_FromLong(totalsize)); totalsize += newdescr->elsize; @@ -974,8 +980,7 @@ _convert_from_dict(PyObject *obj, int align) goto fail; } if (maxalign > 1) { - /* The alignment is always a power of 2, so this works */ - totalsize = (totalsize + maxalign - 1) & (-maxalign); + totalsize = NPY_NEXT_ALIGNED_OFFSET(totalsize, maxalign); } if (align) { new->alignment = maxalign; @@ -2886,7 +2891,7 @@ arraydescr_struct_dict_str(PyArray_Descr *dtype) } /* The alignment is always a power of 2, so this works */ if (align) { - naturalsize = (naturalsize + dtype->alignment - 1) & (-dtype->alignment); + naturalsize = NPY_NEXT_ALIGNED_OFFSET(naturalsize, dtype->alignment); } /* Finally, the itemsize */ if (naturalsize == dtype->elsize) { @@ -2975,12 +2980,12 @@ arraydescr_struct_repr(PyArray_Descr *dtype) /* * This creates a shorter repr using the 'kind' and 'itemsize', - * instead of the longer type name. It also creates the input - * for constructing a dtype rather than the full dtype function - * call. + * instead of the longer type name. This is the object you pass + * as the first parameter to the dtype constructor. * * This does not preserve the 'align=True' parameter - * for structured arrays like the regular repr does. + * for structured arrays like the regular repr does, because + * this flag is separate from the first dtype constructor parameter. */ NPY_NO_EXPORT PyObject * arraydescr_short_construction_repr(PyArray_Descr *dtype) |