MAINT: remove duplicated array extent calculation

2 files changed, 12 insertions, 30 deletions

diff --git a/numpy/core/src/multiarray/array_assign.c b/numpy/core/src/multiarray/array_assign.c
index 4f350388b..6467b6cfd 100644
--- a/numpy/core/src/multiarray/array_assign.c
+++ b/numpy/core/src/multiarray/array_assign.c
@@ -21,6 +21,7 @@
 #include "shape.h"
 
 #include "array_assign.h"
+#include "common.h"
 
 /* See array_assign.h for parameter documentation */
 NPY_NO_EXPORT int
@@ -102,36 +103,14 @@ raw_array_is_aligned(int ndim, char *data, npy_intp *strides, int alignment)
 /* Gets a half-open range [start, end) which contains the array data */
 NPY_NO_EXPORT void
 get_array_memory_extents(PyArrayObject *arr,
-                    npy_uintp *out_start, npy_uintp *out_end)
+                         npy_uintp *out_start, npy_uintp *out_end)
 {
-    npy_uintp start, end;
-    npy_intp idim, ndim = PyArray_NDIM(arr);
-    npy_intp *dimensions = PyArray_DIMS(arr),
-            *strides = PyArray_STRIDES(arr);
-
-    /* Calculate with a closed range [start, end] */
-    start = end = (npy_uintp)PyArray_DATA(arr);
-    for (idim = 0; idim < ndim; ++idim) {
-        npy_intp stride = strides[idim], dim = dimensions[idim];
-        /* If the array size is zero, return an empty range */
-        if (dim == 0) {
-            *out_start = *out_end = (npy_uintp)PyArray_DATA(arr);
-            return;
-        }
-        /* Expand either upwards or downwards depending on stride */
-        else {
-            if (stride > 0) {
-                end += stride*(dim-1);
-            }
-            else if (stride < 0) {
-                start += stride*(dim-1);
-            }
-        }
-    }
-
-    /* Return a half-open range */
-    *out_start = start;
-    *out_end = end + PyArray_DESCR(arr)->elsize;
+    npy_intp low, upper;
+    offset_bounds_from_strides(PyArray_ITEMSIZE(arr), PyArray_NDIM(arr),
+                               PyArray_DIMS(arr), PyArray_STRIDES(arr),
+                               &low, &upper);
+    *out_start = (npy_uintp)PyArray_DATA(arr) + (npy_uintp)low;
+    *out_end = (npy_uintp)PyArray_DATA(arr) + (npy_uintp)upper;
 }
 
 /* Returns 1 if the arrays have overlapping data, 0 otherwise */
diff --git a/numpy/core/src/multiarray/common.c b/numpy/core/src/multiarray/common.c
index 4f25dc913..01bf9cd74 100644
--- a/numpy/core/src/multiarray/common.c
+++ b/numpy/core/src/multiarray/common.c
@@ -688,6 +688,7 @@ _IsWriteable(PyArrayObject *ap)
 }
 
 
+/* Gets a half-open range [start, end) of offsets from the data pointer */
 NPY_NO_EXPORT void
 offset_bounds_from_strides(const int itemsize, const int nd,
                            const npy_intp *dims, const npy_intp *strides,
@@ -699,11 +700,12 @@ offset_bounds_from_strides(const int itemsize, const int nd,
 
     for (i = 0; i < nd; i++) {
         if (dims[i] == 0) {
-            /* Empty array special case */
+            /* If the array size is zero, return an empty range */
             *lower_offset = 0;
             *upper_offset = 0;
             return;
         }
+        /* Expand either upwards or downwards depending on stride */
         max_axis_offset = strides[i] * (dims[i] - 1);
         if (max_axis_offset > 0) {
             upper += max_axis_offset;
@@ -712,6 +714,7 @@ offset_bounds_from_strides(const int itemsize, const int nd,
             lower += max_axis_offset;
         }
     }
+    /* Return a half-open range */
     upper += itemsize;
     *lower_offset = lower;
     *upper_offset = upper;