BUG: fix arrays wrapping foreign data losing their alignment flag

juliantaylor · juliantaylor · commit 83524f678cfb · 2014-07-01T19:24:38.000+02:00
e.g. ufunc_at wraps input arrays which without this fix causes the
iterator to choose much slower unaligned code paths.
Also pointers from malloc can be not aligned for long double types, e.g.
on debian sparc.
diff --git a/numpy/core/src/multiarray/ctors.c b/numpy/core/src/multiarray/ctors.c
@@ -1054,12 +1054,12 @@ PyArray_NewFromDescr_int(PyTypeObject *subtype, PyArray_Descr *descr, int nd,
     fa->data = data;
 
     /*
-     * If the strides were provided to the function, need to
-     * update the flags to get the right CONTIGUOUS, ALIGN properties
+     * always update the flags to get the right CONTIGUOUS, ALIGN properties
+     * not owned data and input strides may not be aligned and on some
+     * platforms (debian sparc) malloc does not provide enough alignment for
+     * long double types
      */
-    if (strides != NULL) {
-        PyArray_UpdateFlags((PyArrayObject *)fa, NPY_ARRAY_UPDATE_ALL);
-    }
+    PyArray_UpdateFlags((PyArrayObject *)fa, NPY_ARRAY_UPDATE_ALL);
 
     /*
      * call the __array_finalize__
