From 13ab570febac64bb55fb46d866a9ba5a46ab8902 Mon Sep 17 00:00:00 2001 From: Disconnect3d Date: Thu, 11 Jul 2019 23:57:42 +0200 Subject: [PATCH] Remove redundant check from arraymodule b_getitem (GH-14676) The `arraymodule`'s `b_getitem` function returns a `PyLong` converted from `arrayobject`'s array, by dereferencing a pointer to `char`. When the `char` type is `signed char`, the `if (x >= 128) x -= 256;` comparison/code is redundant because a `signed char` will have a value of `[-128, 127]` and so `x` will never be greater or equal than 128. This check was indeed needed for situations where a given compiler would assume `char` being `unsigned char` which would make `x` in `[0, 256]` range. However, the check can be removed if we cast the `ob_item` into a signed char pointer (`signed char*`) instead of `char*`. This PR/commit introduces this change. --- Modules/arraymodule.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c index 48986c4190..6aa981daca 100644 --- a/Modules/arraymodule.c +++ b/Modules/arraymodule.c @@ -185,9 +185,7 @@ in bounds; that's the responsibility of the caller. static PyObject * b_getitem(arrayobject *ap, Py_ssize_t i) { - long x = ((char *)ap->ob_item)[i]; - if (x >= 128) - x -= 256; + long x = ((signed char *)ap->ob_item)[i]; return PyLong_FromLong(x); } -- 2.40.0