From: Serhiy Storchaka <storchaka@gmail.com>
Date: Fri, 4 Jan 2013 10:18:35 +0000 (+0200)
Subject: Issue #16674: random.getrandbits() is now 20-40% faster for small integers.
X-Git-Tag: v3.4.0a1~1695
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d8a0bac8f761a72661fa464b34517df5294499d2;p=python

Issue #16674: random.getrandbits() is now 20-40% faster for small integers.
---

diff --git a/Misc/NEWS b/Misc/NEWS
index 7611c07091..310a0b2899 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -201,6 +201,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #16674: random.getrandbits() is now 20-40% faster for small integers.
+
 - Issue #16009: JSON error messages now provide more information.
 
 - Issue #16828: Fix error incorrectly raised by bz2.compress(b'') and
diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index d8927c05b5..a729817f3d 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -360,6 +360,9 @@ random_getrandbits(RandomObject *self, PyObject *args)
         return NULL;
     }
 
+    if (k <= 32)  /* Fast path */
+        return PyLong_FromUnsignedLong(genrand_int32(self) >> (32 - k));
+
     bytes = ((k - 1) / 32 + 1) * 4;
     bytearray = (unsigned char *)PyMem_Malloc(bytes);
     if (bytearray == NULL) {