merge

Cython/Compiler/Nodes.py

@@ -3841,6 +3841,7 @@ class ForFromStatNode(LoopNode, StatNode):
     #
     #  Used internally:
     #
+    #  from_range         bool
     #  is_py_target       bool
     #  loopvar_node       ExprNode (usually a NameNode or temp node)
     #  py_loopvar_node    PyTempNode or None
@@ -3849,6 +3850,7 @@ class ForFromStatNode(LoopNode, StatNode):
     is_py_target = False
     loopvar_node = None
     py_loopvar_node = None
+    from_range = False
 
     def analyse_declarations(self, env):
         self.target.analyse_target_declaration(env)
@@ -3867,13 +3869,15 @@ class ForFromStatNode(LoopNode, StatNode):
         else:
             self.bound1 = self.bound1.coerce_to_integer(env)
             self.bound2 = self.bound2.coerce_to_integer(env)
+        if not self.bound2.is_literal:
+            self.bound2 = self.bound2.coerce_to_temp(env)
         if self.step is not None:
             if isinstance(self.step, ExprNodes.UnaryMinusNode):
                 warning(self.step.pos, "Probable infinite loop in for-from-by statment. Consider switching the directions of the relations.", 2)
             self.step.analyse_types(env)
             self.step = self.step.coerce_to_integer(env)
-        if not (self.bound2.is_name or self.bound2.is_literal):
-            self.bound2 = self.bound2.coerce_to_temp(env)
+            if not self.step.is_literal:
+                self.step = self.step.coerce_to_temp(env)
         target_type = self.target.type
         if not (target_type.is_pyobject or target_type.is_numeric):
             error(self.target.pos,
@@ -3917,49 +3921,45 @@ class ForFromStatNode(LoopNode, StatNode):
             
     def generate_execution_code(self, code):
         old_loop_labels = code.new_loop_labels()
-        from_range = getattr(self, "from_range", False)
+        from_range = self.from_range
         self.bound1.generate_evaluation_code(code)
         self.bound2.generate_evaluation_code(code)
         offset, incop = self.relation_table[self.relation1]
-        if incop == "++":
-            decop = "--"
-        else:
-            decop = "++"
         if self.step is not None:
             self.step.generate_evaluation_code(code)
             step = self.step.result()
             incop = "%s=%s" % (incop[0], step)
-            decop = "%s=%s" % (decop[0], step)
-        loopvar_name = self.loopvar_node.result()
         if from_range:
-            range_bound = code.funcstate.allocate_temp(self.bound2.type, manage_ref=False)
-            code.putln("%s = %s;" % (range_bound, self.bound2.result()))
-            # Skip the loop entirely (and avoid assigning to the loopvar) if
-            # the loop is empty:
-            code.putln("if (%s%s %s %s) {" % (
-                self.bound1.result(), offset, self.relation2, range_bound
-                ))
+            loopvar_name = code.funcstate.allocate_temp(self.target.type, False)
         else:
-            range_bound = self.bound2.result()
+            loopvar_name = self.loopvar_node.result()
         code.putln(
             "for (%s = %s%s; %s %s %s; %s%s) {" % (
                 loopvar_name,
                 self.bound1.result(), offset,
-                loopvar_name, self.relation2, range_bound,
+                loopvar_name, self.relation2, self.bound2.result(),
                 loopvar_name, incop))
         if self.py_loopvar_node:
             self.py_loopvar_node.generate_evaluation_code(code)
             self.target.generate_assignment_code(self.py_loopvar_node, code)
+        elif from_range:
+            code.putln("%s = %s;" % (
+                            self.target.result(), loopvar_name))
         self.body.generate_execution_code(code)
         code.put_label(code.continue_label)
-        if from_range:
-            # Undo last increment to maintain Python semantics:
-            code.putln("} %s%s;" % (loopvar_name, decop))
-            # End the outer if statement:
-            code.putln("} /* end if */")
-            code.funcstate.release_temp(range_bound)
-        else:
-            code.putln("}")
+        if self.py_loopvar_node:
+            # Reassign py variable to loop var here.
+            # (For consistancy, should rarely come up in practice.)
+            import ExprNodes
+            from_py_node = ExprNodes.CoerceFromPyTypeNode(self.loopvar_node.type, self.target, None)
+            from_py_node.temp_code = loopvar_name
+            from_py_node.generate_result_code(code)
+        code.putln("}")
+        if self.py_loopvar_node:
+            # This is potentially wasteful, but we don't want the semantics to 
+            # depend on whether or not the loop is a python type. 
+            self.py_loopvar_node.generate_evaluation_code(code)
+            self.target.generate_assignment_code(self.py_loopvar_node, code)
         break_label = code.break_label
         code.set_loop_labels(old_loop_labels)
         if self.else_clause:
@@ -3974,6 +3974,8 @@ class ForFromStatNode(LoopNode, StatNode):
         if self.step is not None:
             self.step.generate_disposal_code(code)
             self.step.free_temps(code)
+        if from_range:
+            code.funcstate.release_temp(loopvar_name)
     
     relation_table = {
         # {relop : (initial offset, increment op)}

Cython/Compiler/Optimize.py

@@ -144,7 +144,6 @@ class IterationTransform(Visitor.VisitorTransform):
             relation2=relation2, bound2=bound2,
             step=step, body=node.body,
             else_clause=node.else_clause,
-            loopvar_node=node.target,
             from_range=True)
         return for_node
 

tests/run/for_decrement.pyx

@@ -4,10 +4,6 @@
 (9, 9, 8, 1, 2)
 >>> from_loop_indices()
 ** Calculating step **
-** Calculating step **
-** Calculating step **
-** Calculating step **
-** Calculating step **
 (10, 10, 0)
 """
 

tests/run/range_optimisation_T203.pyx

 __doc__ = u"""
->>> test_var(10, 5)
+>>> for_from_range(5, 10)
+range(5)
+at 0
+at 1
+at 2
+at 3
+at 4
+range(5, 10)
+at 5
+at 6
+at 7
+at 8
+at 9
+range(5, 10, 2)
+at 5
+at 7
+at 9
+9
+>>> for_from_range(-5, -10)
+range(-5)
+range(-5, -10)
+range(-5, -10, 2)
+100
+>>> for_from_bound_reassignment(5, 1)
 at 0
 at 1
 at 2
 at 3
 at 4
 5
+>>> for_from_step_reassignment(15, 5, 2)
+at 0
+at 5
+at 10
+15
+>>> for_from_target_reassignment(10, 2)
+at 0
+at 1
+at 3
+at 7
+15
+>>> for_from_py_target_reassignment(10, 2)
+at 0
+at 1
+at 3
+at 7
+15
+>>> for_in_target_reassignment(10, 2)
+at 0
+at 1
+at 2
+at 3
+at 4
+at 5
+at 6
+at 7
+at 8
+at 9
+18
 >>> test_func(5)
 get_bound(5)
 at 0
@@ -14,47 +66,61 @@ at 2
 at 3
 at 4
 5
->>> test_f()
-9
->>> f()
-g called
-0
-1
-2
-2
 """
-
 cdef int get_bound(int m):
     print "get_bound(%s)"%m
     return m
 
-def test_var(int n, int m):
-    cdef int i
-    for i from 0 <= i < n:
+def for_from_range(a, b):
+    cdef int i = 100
+    print "range(%s)" % a
+    for i in range(a):
+        print "at", i
+    print "range(%s, %s)" % (a, b)
+    for i in range(a, b):
+        print "at", i
+    print "range(%s, %s, %s)" % (a, b, 2)
+    for i in range(a, b, 2):
         print "at", i
-        n = m
     return i
 
-def test_func(int n):
-    cdef int i
-    for i from 0 <= i < get_bound(n):
+def for_from_bound_reassignment(int bound, int fake_bound):
+    cdef int i = 100
+    for i from 0 <= i < bound:
         print "at", i
+        bound = fake_bound
     return i
 
-def test_f():
-    cdef int i,n
-    n = 10
-    for i in range(n):
-      if i == 5: n *= 2
-    print i
+def for_from_step_reassignment(int bound, int step, int fake_step):
+    cdef int i = 100
+    for i from 0 <= i < bound by step:
+        print "at", i
+        step = fake_step
+    return i
+
+def for_from_target_reassignment(int bound, int factor):
+    cdef int i = 100
+    for i from 0 <= i < bound:
+        print "at", i
+        i *= factor
+    return i
 
-cdef int g():
-    print "g called"
-    return 3
+def for_from_py_target_reassignment(int bound, int factor):
+    cdef object i
+    for i from 0 <= i < bound:
+        print "at", i
+        i *= factor
+    return i
 
-def f():
-    cdef int i = -1
-    for i in range(g()):
-        print i
-    print i
+def for_in_target_reassignment(int bound, int factor):
+    cdef int i = 100
+    for i in range(bound):
+        print "at", i
+        i *= factor
+    return i
 
+def test_func(int n):
+    cdef int i = 100
+    for i from 0 <= i < get_bound(n):
+        print "at", i
+    return i