optimise frozenset(it) into a call to PyFrozenSet_New(it)

Cython/Compiler/Optimize.py

@@ -1986,20 +1986,14 @@ class OptimizeBuiltinCalls(Visitor.MethodDispatcherTransform):
             is_temp = node.is_temp
             )
 
-    PyObject_AsDouble_func_type = PyrexTypes.CFuncType(
-        PyrexTypes.c_double_type, [
-            PyrexTypes.CFuncTypeArg("obj", PyrexTypes.py_object_type, None),
-            ],
-        exception_value = "((double)-1)",
-        exception_check = True)
-
     PySet_New_func_type = PyrexTypes.CFuncType(
         Builtin.set_type, [
             PyrexTypes.CFuncTypeArg("it", PyrexTypes.py_object_type, None)
         ])
 
     def _handle_simple_function_set(self, node, function, pos_args):
-        if len(pos_args) == 1:
+        if len(pos_args) != 1:
+            return node
         if pos_args[0].is_sequence_constructor:
             # We can optimise set([x,y,z]) safely into a set literal,
             # but only if we create all items before adding them -
@@ -2026,7 +2020,30 @@ class OptimizeBuiltinCalls(Visitor.MethodDispatcherTransform):
                 is_temp=node.is_temp,
                 utility_code=UtilityCode.load_cached('pyset_compat', 'Builtins.c'),
                 py_name="set")
+
+    PyFrozenSet_New_func_type = PyrexTypes.CFuncType(
+        Builtin.frozenset_type, [
+            PyrexTypes.CFuncTypeArg("it", PyrexTypes.py_object_type, None)
+        ])
+
+    def _handle_simple_function_frozenset(self, node, function, pos_args):
+        if len(pos_args) != 1:
             return node
+        # PyFrozenSet_New(it) is better than a generic Python call to frozenset(it)
+        return ExprNodes.PythonCapiCallNode(
+            node.pos, "PyFrozenSet_New",
+            self.PyFrozenSet_New_func_type,
+            args=pos_args,
+            is_temp=node.is_temp,
+            utility_code=UtilityCode.load_cached('pyset_compat', 'Builtins.c'),
+            py_name="frozenset")
+
+    PyObject_AsDouble_func_type = PyrexTypes.CFuncType(
+        PyrexTypes.c_double_type, [
+            PyrexTypes.CFuncTypeArg("obj", PyrexTypes.py_object_type, None),
+            ],
+        exception_value = "((double)-1)",
+        exception_check = True)
 
     def _handle_simple_function_float(self, node, function, pos_args):
         """Transform float() into either a C type cast or a faster C

tests/run/set.pyx

 
 # Py2.3 doesn't have the 'set' builtin type, but Cython does :)
 _set = set
+_frozenset = frozenset
 
 cimport cython
 
+
 def cython_set():
     """
     >>> cython_set() is _set
@@ -12,6 +14,16 @@ def cython_set():
     assert set is cython.set
     return cython.set
 
+
+def cython_frozenset():
+    """
+    >>> cython_frozenset() is _frozenset
+    True
+    """
+    assert frozenset is cython.frozenset
+    return cython.frozenset
+
+
 def cython_set_override():
     """
     >>> cython_set_override() is _set
@@ -20,6 +32,16 @@ def cython_set_override():
     set = 1
     return cython.set
 
+
+def cython_frozenset_override():
+    """
+    >>> cython_frozenset_override() is _frozenset
+    True
+    """
+    frozenset = 1
+    return cython.frozenset
+
+
 def test_set_literal():
     """
     >>> type(test_set_literal()) is _set
@@ -30,6 +52,7 @@ def test_set_literal():
     cdef set s1 = {1,'a',1,'b','a'}
     return s1
 
+
 def test_set_add():
     """
     >>> type(test_set_add()) is _set
@@ -45,6 +68,7 @@ def test_set_add():
     s1.add((1,2))
     return s1
 
+
 def test_set_clear():
     """
     >>> type(test_set_clear()) is _set
@@ -57,6 +81,7 @@ def test_set_clear():
     s1.clear()
     return s1
 
+
 def test_set_clear_None():
     """
     >>> test_set_clear_None()
@@ -66,6 +91,7 @@ def test_set_clear_None():
     cdef set s1 = None
     s1.clear()
 
+
 def test_set_list_comp():
     """
     >>> type(test_set_list_comp()) is _set
@@ -77,6 +103,19 @@ def test_set_list_comp():
     s1 = set([i%3 for i in range(5)])
     return s1
 
+
+def test_frozenset_list_comp():
+    """
+    >>> type(test_frozenset_list_comp()) is _frozenset
+    True
+    >>> sorted(test_frozenset_list_comp())
+    [0, 1, 2]
+    """
+    cdef frozenset s1
+    s1 = frozenset([i%3 for i in range(5)])
+    return s1
+
+
 def test_set_pop():
     """
     >>> type(test_set_pop()) is _set
@@ -90,6 +129,7 @@ def test_set_pop():
     two = s1.pop()
     return s1
 
+
 @cython.test_fail_if_path_exists("//SimpleCallNode//NameNode")
 def test_object_pop(s):
     """
@@ -101,6 +141,7 @@ def test_object_pop(s):
     """
     return s.pop()
 
+
 def test_set_discard():
     """
     >>> type(test_set_discard()) is _set
@@ -117,6 +158,7 @@ def test_set_discard():
     s1.discard(3)
     return s1
 
+
 def test_set_sideeffect_unhashable_failure():
     """
     >>> test_set_sideeffect_unhashable_failure()
@@ -135,8 +177,31 @@ def test_set_sideeffect_unhashable_failure():
     else: assert False, "expected exception not raised"
     return L
 
+
+def test_frozenset_sideeffect_unhashable_failure():
+    """
+    >>> test_frozenset_sideeffect_unhashable_failure()
+    [2, 4, 5]
+    """
+    L = []
+    def sideeffect(x):
+        L.append(x)
+        return x
+    def unhashable_value(x):
+        L.append(x)
+        return set()
+    try:
+        s = frozenset([1,sideeffect(2),3,unhashable_value(4),sideeffect(5)])
+    except TypeError: pass
+    else: assert False, "expected exception not raised"
+    return L
+
+
 @cython.test_assert_path_exists("//SetNode")
-@cython.test_fail_if_path_exists("//SimpleCallNode")
+@cython.test_fail_if_path_exists(
+    "//SimpleCallNode",
+    "//PythonCapiCallNode"
+)
 def test_set_of_list():
     """
     >>> s = test_set_of_list()
@@ -147,6 +212,20 @@ def test_set_of_list():
     """
     return set([1, 2, 3])
 
+
+@cython.test_assert_path_exists("//PythonCapiCallNode")
+@cython.test_fail_if_path_exists("//SetNode")
+def test_frozenset_of_list():
+    """
+    >>> s = test_frozenset_of_list()
+    >>> isinstance(s, _frozenset)
+    True
+    >>> sorted(s)
+    [1, 2, 3]
+    """
+    return frozenset([1, 2, 3])
+
+
 @cython.test_assert_path_exists("//SetNode")
 @cython.test_fail_if_path_exists("//SimpleCallNode")
 def test_set_of_tuple():
@@ -159,6 +238,52 @@ def test_set_of_tuple():
     """
     return set((1, 2, 3))
 
+
+@cython.test_assert_path_exists("//PythonCapiCallNode")
+@cython.test_fail_if_path_exists("//SetNode")
+def test_frozenset_of_tuple():
+    """
+    >>> s = test_frozenset_of_tuple()
+    >>> isinstance(s, _frozenset)
+    True
+    >>> sorted(s)
+    [1, 2, 3]
+    """
+    return frozenset((1, 2, 3))
+
+
+@cython.test_assert_path_exists("//PythonCapiCallNode")
+@cython.test_fail_if_path_exists(
+    "//SimpleCallNode",
+    "//SetNode"
+)
+def test_set_of_iterable(x):
+    """
+    >>> s = test_set_of_iterable([1, 2, 3])
+    >>> isinstance(s, _set)
+    True
+    >>> sorted(s)
+    [1, 2, 3]
+    """
+    return set(x)
+
+
+@cython.test_assert_path_exists("//PythonCapiCallNode")
+@cython.test_fail_if_path_exists(
+    "//SimpleCallNode",
+    "//SetNode"
+)
+def test_frozenset_of_iterable(x):
+    """
+    >>> s = test_frozenset_of_iterable([1, 2, 3])
+    >>> isinstance(s, _frozenset)
+    True
+    >>> sorted(s)
+    [1, 2, 3]
+    """
+    return frozenset(x)
+
+
 def sorted(it):
     # Py3 can't compare different types
     chars = []