Restore radixsort for ascending sorts

numpy · seberg · May 13, 2026 · Apr 20, 2026 · Apr 20, 2026 · Apr 20, 2026
commit 4b3a48154a42add8931208d848a47ae91b33a46a
diff --git a/numpy/_core/meson.build b/numpy/_core/meson.build
@@ -1234,7 +1234,6 @@ src_multiarray = multiarray_gen_headers + [
   'src/npysort/mergesort.cpp',
   'src/npysort/timsort_generic.cpp',
   'src/npysort/heapsort.cpp',
-  'src/npysort/radixsort.cpp',
   'src/npysort/npysort_methods.cpp',
   'src/common/npy_partition.h',
   'src/npysort/selection.cpp',

diff --git a/numpy/_core/src/npysort/npysort_methods.cpp b/numpy/_core/src/npysort/npysort_methods.cpp
@@ -4,6 +4,7 @@
 #include "npysort_common.h"
 #include "numpy_tag.h"
 #include "quicksort.hpp"
+#include "radixsort.hpp"
 #include "timsort.hpp"
 
 #include <cstdlib>
@@ -53,13 +54,26 @@ sort_loop_(PyArrayMethod_Context *context, char *const data[],
            npy_intp const dimensions[], npy_intp const strides[],
            NpyAuxData *NPY_UNUSED(auxdata))
 {
+    constexpr bool use_radixsort = (
+        std::is_same_v<Tag, npy::bool_tag> ||
+        std::is_same_v<Tag, npy::ubyte_tag> ||
+        std::is_same_v<Tag, npy::byte_tag> ||
+        std::is_same_v<Tag, npy::ushort_tag> ||
+        std::is_same_v<Tag, npy::short_tag>
+    );
+
     PyArrayMethod_SortParameters *params =
             (PyArrayMethod_SortParameters *)context->parameters;
     switch ((int)params->flags) {
         case NPY_SORT_DEFAULT:
             return quicksort_<Tag, type, false>((type *)data[0], dimensions[0]);
         case NPY_SORT_STABLE:
+        if constexpr (use_radixsort) {
+            return radixsort<type>(data[0], dimensions[0]);
+        }
+        else {
             return timsort_<Tag, type, false>((type *)data[0], dimensions[0]);
+        }
         case NPY_SORT_DEFAULT | NPY_SORT_DESCENDING:
             return quicksort_<Tag, type, true>((type *)data[0], dimensions[0]);
         case NPY_SORT_STABLE | NPY_SORT_DESCENDING:
@@ -77,15 +91,28 @@ argsort_loop_(PyArrayMethod_Context *context, char *const data[],
               npy_intp const dimensions[], npy_intp const strides[],
               NpyAuxData *NPY_UNUSED(auxdata))
 {
+    constexpr bool use_radixsort = (
+        std::is_same_v<Tag, npy::bool_tag> ||
+        std::is_same_v<Tag, npy::ubyte_tag> ||
+        std::is_same_v<Tag, npy::byte_tag> ||
+        std::is_same_v<Tag, npy::ushort_tag> ||
+        std::is_same_v<Tag, npy::short_tag>
+    );
+
     PyArrayMethod_SortParameters *params =
             (PyArrayMethod_SortParameters *)context->parameters;
     switch ((int)params->flags) {
         case NPY_SORT_DEFAULT:
             return aquicksort_<Tag, type, false>((type *)data[0], (npy_intp *)data[1],
                                                  dimensions[0]);
         case NPY_SORT_STABLE:
+        if constexpr (use_radixsort) {
+            return aradixsort<type>(data[0], (npy_intp *)data[1], dimensions[0]);
+        }
+        else {
             return atimsort_<Tag, type, false>((type *)data[0], (npy_intp *)data[1],
                                                dimensions[0]);
+        }
         case NPY_SORT_DEFAULT | NPY_SORT_DESCENDING:
             return aquicksort_<Tag, type, true>((type *)data[0], (npy_intp *)data[1],
                                                 dimensions[0]);

diff --git a/numpy/_core/src/npysort/radixsort.cpp → numpy/_core/src/npysort/radixsort.hpp b/numpy/_core/src/npysort/radixsort.cpp → numpy/_core/src/npysort/radixsort.hpp
@@ -235,122 +235,3 @@ aradixsort(void *start, npy_intp *tosort, npy_intp num)
     using UT = typename std::make_unsigned<T>::type;
     return aradixsort_<T>((UT *)start, tosort, num);
 }
-
-extern "C" {
-NPY_NO_EXPORT int
-radixsort_bool(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_bool>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_byte(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_byte>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_ubyte(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_ubyte>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_short(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_short>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_ushort(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_ushort>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_int(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_int>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_uint(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_uint>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_long(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_long>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_ulong(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_ulong>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_longlong(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_longlong>(vec, cnt);
-}
-NPY_NO_EXPORT int
-radixsort_ulonglong(void *vec, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return radixsort<npy_ulonglong>(vec, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_bool(void *vec, npy_intp *ind, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_bool>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_byte(void *vec, npy_intp *ind, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_byte>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_ubyte(void *vec, npy_intp *ind, npy_intp cnt,
-                 void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_ubyte>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_short(void *vec, npy_intp *ind, npy_intp cnt,
-                 void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_short>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_ushort(void *vec, npy_intp *ind, npy_intp cnt,
-                  void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_ushort>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_int(void *vec, npy_intp *ind, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_int>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_uint(void *vec, npy_intp *ind, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_uint>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_long(void *vec, npy_intp *ind, npy_intp cnt, void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_long>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_ulong(void *vec, npy_intp *ind, npy_intp cnt,
-                 void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_ulong>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_longlong(void *vec, npy_intp *ind, npy_intp cnt,
-                    void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_longlong>(vec, ind, cnt);
-}
-NPY_NO_EXPORT int
-aradixsort_ulonglong(void *vec, npy_intp *ind, npy_intp cnt,
-                     void *NPY_UNUSED(null))
-{
-    return aradixsort<npy_ulonglong>(vec, ind, cnt);
-}
-}