[pypy-commit] pypy default: move sum() to app-level, it's significantly faster with the JIT, particularly in cases such as a generator expressions, where the storage can be unboxed.

[alex_gaynor]

Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: 
Changeset: r46882:92e36ab4eb5e
Date: 2011-08-29 05:05 -0400
http://bitbucket.org/pypy/pypy/changeset/92e36ab4eb5e/

Log:	move sum() to app-level, it's significantly faster with the JIT,
	particularly in cases such as a generator expressions, where the
	storage can be unboxed.

diff --git a/pypy/module/__builtin__/__init__.py b/pypy/module/__builtin__/__init__.py
--- a/pypy/module/__builtin__/__init__.py
+++ b/pypy/module/__builtin__/__init__.py
@@ -19,6 +19,7 @@
         'sorted'        : 'app_functional.sorted',
         'any'           : 'app_functional.any',
         'all'           : 'app_functional.all',
+        'sum'           : 'app_functional.sum',
         'vars'          : 'app_inspect.vars',
         'dir'           : 'app_inspect.dir',
 
@@ -85,7 +86,6 @@
         'enumerate'     : 'functional.W_Enumerate',
         'min'           : 'functional.min',
         'max'           : 'functional.max',
-        'sum'           : 'functional.sum',
         'map'           : 'functional.map',
         'zip'           : 'functional.zip',
         'reduce'        : 'functional.reduce',
@@ -118,7 +118,7 @@
                 return module.Module(space, None, w_builtin)
            builtin = space.interpclass_w(w_builtin)
            if isinstance(builtin, module.Module):
-               return builtin   
+               return builtin
        # no builtin! make a default one.  Given them None, at least.
        builtin = module.Module(space, None)
        space.setitem(builtin.w_dict, space.wrap('None'), space.w_None)
diff --git a/pypy/module/__builtin__/app_functional.py b/pypy/module/__builtin__/app_functional.py
--- a/pypy/module/__builtin__/app_functional.py
+++ b/pypy/module/__builtin__/app_functional.py
@@ -34,3 +34,18 @@
         if not x:
             return False
     return True
+
+def sum(sequence, start=0):
+    """sum(sequence[, start]) -> value
+
+Returns the sum of a sequence of numbers (NOT strings) plus the value
+of parameter 'start' (which defaults to 0).  When the sequence is
+empty, returns start."""
+    if isinstance(start, basestring):
+        raise TypeError("sum() can't sum strings")
+    last = start
+    for x in sequence:
+        # Very intentionally *not* +=, that would have different semantics if
+        # start was a mutable type, such as a list
+        last = last + x
+    return last
\ No newline at end of file
diff --git a/pypy/module/__builtin__/functional.py b/pypy/module/__builtin__/functional.py
--- a/pypy/module/__builtin__/functional.py
+++ b/pypy/module/__builtin__/functional.py
@@ -325,27 +325,6 @@
         result_w.append(w_res)
     return result_w
 
-def sum(space, w_sequence, w_start=0):
-    """sum(sequence[, start]) -> value
-
-Returns the sum of a sequence of numbers (NOT strings) plus the value
-of parameter 'start' (which defaults to 0).  When the sequence is
-empty, returns start."""
-    if space.is_true(space.isinstance(w_start, space.w_basestring)):
-        msg = "sum() can't sum strings"
-        raise OperationError(space.w_TypeError, space.wrap(msg))
-    w_iter = space.iter(w_sequence)
-    w_last = w_start
-    while True:
-        try:
-            w_next = space.next(w_iter)
-        except OperationError, e:
-            if not e.match(space, space.w_StopIteration):
-                raise
-            break
-        w_last = space.add(w_last, w_next)
-    return w_last
-
 @unwrap_spec(sequences_w="args_w")
 def zip(space, sequences_w):
     """Return a list of tuples, where the nth tuple contains every nth item of