MAINT Use C99 functions from Cython (#15098)

sklearn/cluster/_hierarchical.pyx

@@ -18,17 +18,14 @@ from ..utils.fast_dict cimport IntFloatDict
 # C++
 from cython.operator cimport dereference as deref, preincrement as inc
 from libcpp.map cimport map as cpp_map
+from libc.math cimport fmax
 
 DTYPE = np.float64
 ctypedef np.float64_t DTYPE_t
 
 ITYPE = np.intp
 ctypedef np.intp_t ITYPE_t
 
-# Reimplementation for MSVC support
-cdef inline double fmax(double a, double b):
-    return max(a, b)
-
 ###############################################################################
 # Utilities for computing the ward momentum
 

sklearn/neighbors/binary_tree.pxi

@@ -145,6 +145,7 @@
 cimport cython
 cimport numpy as np
 from libc.math cimport fabs, sqrt, exp, cos, pow, log, lgamma
+from libc.math cimport fmin, fmax
 from libc.stdlib cimport calloc, malloc, free
 from libc.string cimport memcpy
 
@@ -2610,12 +2611,6 @@ def nodeheap_sort(DTYPE_t[::1] vals):
 
     return np.asarray(vals_sorted), np.asarray(indices)
 
-# Reimplementation for MSVC support
-cdef inline double fmin(double a, double b):
-    return min(a, b)
-
-cdef inline double fmax(double a, double b) nogil:
-    return max(a, b)
 
 cdef inline DTYPE_t _total_node_weight(NodeData_t* node_data,
                                        DTYPE_t* sample_weight,

sklearn/neighbors/quad_tree.pyx

@@ -11,6 +11,7 @@ from cpython cimport Py_INCREF, PyObject, PyTypeObject
 from libc.stdlib cimport malloc, free
 from libc.string cimport memcpy
 from libc.stdio cimport printf
+from libc.stdint cimport SIZE_MAX
 
 from ..tree._utils cimport safe_realloc, sizet_ptr_to_ndarray
 from ..utils import check_array
@@ -29,11 +30,6 @@ cdef extern from "numpy/arrayobject.h":
                                 void* data, int flags, object obj)
 
 
-# XXX using (size_t)(-1) is ugly, but SIZE_MAX is not available in C89
-# (i.e., older MSVC).
-cdef SIZE_t DEFAULT = <SIZE_t>(-1)
-
-
 # Repeat struct definition for numpy
 CELL_DTYPE = np.dtype({
     'names': ['parent', 'children', 'cell_id', 'point_index', 'is_leaf',
@@ -215,14 +211,14 @@ cdef class _QuadTree:
             Cell* child
             int i
 
-        # If the maximal capacity of the Tree have been reach, double the capacity
+        # If the maximal capacity of the Tree have been reached, double the capacity
         # We need to save the current cell id and the current point to retrieve them
         # in case the reallocation
         if self.cell_count + 1 > self.capacity:
             parent_id = cell.cell_id
             for i in range(self.n_dimensions):
                 save_point[i] = point[i]
-            self._resize(DEFAULT)
+            self._resize(SIZE_MAX)
             cell = &self.cells[parent_id]
             point = save_point
 
@@ -305,7 +301,7 @@ cdef class _QuadTree:
         cell.squared_max_width = 0
         cell.cumulative_size = 0
         for i in range(self.n_cells_per_cell):
-            cell.children[i] = DEFAULT
+            cell.children[i] = SIZE_MAX
 
     cdef void _init_root(self, DTYPE_t[3] min_bounds, DTYPE_t[3] max_bounds
                          ) nogil:
@@ -592,7 +588,7 @@ cdef class _QuadTree:
             with gil:
                 raise MemoryError()
 
-    cdef int _resize_c(self, SIZE_t capacity=DEFAULT) nogil except -1:
+    cdef int _resize_c(self, SIZE_t capacity=SIZE_MAX) nogil except -1:
         """Guts of _resize
 
         Returns -1 in case of failure to allocate memory (and raise MemoryError)
@@ -601,7 +597,7 @@ cdef class _QuadTree:
         if capacity == self.capacity and self.cells != NULL:
             return 0
 
-        if capacity == DEFAULT:
+        if capacity == SIZE_MAX:
             if self.capacity == 0:
                 capacity = 9  # default initial value to min
             else:

sklearn/tree/_tree.pyx

@@ -22,6 +22,7 @@ from libc.stdlib cimport free
 from libc.math cimport fabs
 from libc.string cimport memcpy
 from libc.string cimport memset
+from libc.stdint cimport SIZE_MAX
 
 import numpy as np
 cimport numpy as np
@@ -244,7 +245,7 @@ cdef class DepthFirstTreeBuilder(TreeBuilder):
                                          split.threshold, impurity, n_node_samples,
                                          weighted_n_node_samples)
 
-                if node_id == <SIZE_t>(-1):
+                if node_id == SIZE_MAX:
                     rc = -1
                     break
 
@@ -468,7 +469,7 @@ cdef class BestFirstTreeBuilder(TreeBuilder):
                                  is_left, is_leaf,
                                  split.feature, split.threshold, impurity, n_node_samples,
                                  weighted_n_node_samples)
-        if node_id == <SIZE_t>(-1):
+        if node_id == SIZE_MAX:
             return -1
 
         # compute values also for split nodes (might become leafs later).
@@ -691,9 +692,7 @@ cdef class Tree:
             with gil:
                 raise MemoryError()
 
-    # XXX using (size_t)(-1) is ugly, but SIZE_MAX is not available in C89
-    # (i.e., older MSVC).
-    cdef int _resize_c(self, SIZE_t capacity=<SIZE_t>(-1)) nogil except -1:
+    cdef int _resize_c(self, SIZE_t capacity=SIZE_MAX) nogil except -1:
         """Guts of _resize
 
         Returns -1 in case of failure to allocate memory (and raise MemoryError)
@@ -702,7 +701,7 @@ cdef class Tree:
         if capacity == self.capacity and self.nodes != NULL:
             return 0
 
-        if capacity == <SIZE_t>(-1):
+        if capacity == SIZE_MAX:
             if self.capacity == 0:
                 capacity = 3  # default initial value
             else:
@@ -738,7 +737,7 @@ cdef class Tree:
 
         if node_id >= self.capacity:
             if self._resize_c() != 0:
-                return <SIZE_t>(-1)
+                return SIZE_MAX
 
         cdef Node* node = &self.nodes[node_id]
         node.impurity = impurity
@@ -1619,7 +1618,7 @@ cdef _build_pruned_tree(
                 node.impurity, node.n_node_samples,
                 node.weighted_n_node_samples)
 
-            if new_node_id == <SIZE_t>(-1):
+            if new_node_id == SIZE_MAX:
                 rc = -1
                 break