range.diff

Index: numba/specialize/loops.py
===================================================================
--- numba/specialize/loops.py    (revision 79617)
+++ numba/specialize/loops.py    (revision 83202)
@@ -95,36 +105,31 @@
         else:
             have_step = True

-        start, stop, step = [nodes.CloneableNode(n)
-                             for n in (start, stop, step)]
+        start, stop, step = map(nodes.CloneableNode, (start, stop, step))

         if have_step:
-            compute_nsteps = """
-                    $length = {{stop}} - {{start}}
-                    {{nsteps}} = $length / {{step}}
-                    if {{nsteps_load}} * {{step}} != $length: #$length % {{step}}:
-                        # Test for truncation
-                        {{nsteps}} = {{nsteps_load}} + 1
-                    # print "nsteps", {{nsteps_load}}
-                """
+            templ = textwrap.dedent("""
+                    {{temp}} = 0
+                    {{nsteps}} = ({{stop}} - {{start}} + {{step}} -
+                                    (1 if {{step}} >= 0 else -1)) / {{step}}
+                    while {{temp_load}} < {{nsteps_load}}:
+                        {{target}} = {{start}} + {{temp_load}} * {{step}}
+                        {{body}}
+                        {{temp}} = {{temp_load}} + 1
+                """)
         else:
-            compute_nsteps = "{{nsteps}} = {{stop}} - {{start}}"
+            templ = textwrap.dedent("""
+                    {{temp}} = {{start}}
+                    {{nsteps}} = {{stop}}
+                    while {{temp_load}} < {{nsteps_load}}:
+                        {{target}} = {{temp_load}}
+                        {{body}}
+                        {{temp}} = {{temp_load}} + 1
+                """)

         if node.orelse:
-            else_clause = "else: {{else_body}}"
-        else:
-            else_clause = ""
+            templ += "\nelse: {{else_body}}"

-        templ = textwrap.dedent("""
-                %s
-                {{temp}} = 0
-                while {{temp_load}} < {{nsteps_load}}:
-                    {{target}} = {{start}} + {{temp_load}} * {{step}}
-                    {{body}}
-                    {{temp}} = {{temp_load}} + 1
-                %s
-            """) % (textwrap.dedent(compute_nsteps), else_clause)
-
         # Leave the bodies empty, they are already analyzed
         body = ast.Suite(body=[])
         else_body = ast.Suite(body=[])
@@ -196,8 +201,7 @@
         # Replace node.target with a temporary
         #--------------------------------------------------------------------

-        target_name = orig_target.id + '.idx'
-        target_temp = nodes.TempNode(Py_ssize_t)
+        target_temp = nodes.TempNode(typesystem.Py_ssize_t)
         node.target = target_temp.store()

         #--------------------------------------------------------------------

test_ast_forloop.py

from   numba import autojit
import numpy as np
import unittest

@autojit
def for_loop_fn_1 (start, stop, inc):
    acc = 0
    for value in range(start, stop, inc):
        acc += value
    return acc

@autojit
def for_loop_fn_1a (start, stop):
    acc = 0
    for value in range(start, stop):
        acc += value
    return acc

@autojit
def for_loop_fn_1b (stop):
    acc = 0
    for value in range(stop):
        acc += value
    return acc


class TestForLoop(unittest.TestCase):
    def test_compiled_for_loop_fn_many(self):
        for lo in xrange( -10, 11 ):
            for hi in xrange( -10, 11 ):
                for step in xrange( -20, 21 ):
                    if step:
                        self.assertEqual(for_loop_fn_1(lo, hi, step),
                                         for_loop_fn_1.py_func(lo, hi, step),
                                         'failed for %d/%d/%d' % (lo, hi, step))
                        self.assertEqual(for_loop_fn_1a(lo, hi),
                                         for_loop_fn_1a.py_func(lo, hi),
                                         'failed for %d/%d' % (lo, hi))
                        self.assertEqual(for_loop_fn_1b(hi),
                                         for_loop_fn_1b.py_func(hi),
                                         'failed for %d' % hi)