I observed a code clone from the following files. function : dlpvalloc @ (file: "Python-3.3.0a2/Modules/_ctypes/libffi/src/dlmalloc.c", line: 4360)~4362 function : dlvalloc @ (file: "Python-3.3.0a2/Modules/_ctypes/libffi/src/dlmalloc.c", line: 4353)~4355 The function dlpvalloc performs a bitwise operation at return while dlvalloc does not. I wonder if this is necessary in dlvalloc. The source code is included in the attachment. Hope it helps.