Bug #1586448: the compiler module now emits the same bytecode for
list comprehensions as the builtin compiler, using the LIST_APPEND
opcode.
diff --git a/Lib/compiler/pycodegen.py b/Lib/compiler/pycodegen.py
index 009438d..0e226fd 100644
--- a/Lib/compiler/pycodegen.py
+++ b/Lib/compiler/pycodegen.py
@@ -573,12 +573,11 @@
def visitListComp(self, node):
self.set_lineno(node)
# setup list
- append = "$append%d" % self.__list_count
+ tmpname = "$list%d" % self.__list_count
self.__list_count = self.__list_count + 1
self.emit('BUILD_LIST', 0)
self.emit('DUP_TOP')
- self.emit('LOAD_ATTR', 'append')
- self._implicitNameOp('STORE', append)
+ self._implicitNameOp('STORE', tmpname)
stack = []
for i, for_ in zip(range(len(node.quals)), node.quals):
@@ -590,10 +589,9 @@
self.visit(if_, cont)
stack.insert(0, (start, cont, anchor))
- self._implicitNameOp('LOAD', append)
+ self._implicitNameOp('LOAD', tmpname)
self.visit(node.expr)
- self.emit('CALL_FUNCTION', 1)
- self.emit('POP_TOP')
+ self.emit('LIST_APPEND',)
for start, cont, anchor in stack:
if cont:
@@ -604,7 +602,7 @@
self.nextBlock(skip_one)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
- self._implicitNameOp('DELETE', append)
+ self._implicitNameOp('DELETE', tmpname)
self.__list_count = self.__list_count - 1
diff --git a/Misc/NEWS b/Misc/NEWS
index 605a862..8cb10fa 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -89,6 +89,10 @@
Library
-------
+- Bug #1586448: the compiler module now emits the same bytecode for
+ list comprehensions as the builtin compiler, using the LIST_APPEND
+ opcode.
+
- Fix codecs.EncodedFile which did not use file_encoding in 2.5.0, and
fix all codecs file wrappers to work correctly with the "with"
statement (bug #1586513).