Sage 3.4.2: prime_pi() broken on 32 bit

[sagetrac-mabshoff]

The issue is that Integer(2^40) is evaluated to 0 on 32 bit systems (maybe due to Cython folding constants?). The attached patch uses a long constant instead. Tested to work on 32 and 64 bit boxen.

Cheers,

Michael

Component: doctest coverage

Issue created by migration from https://trac.sagemath.org/ticket/5981

[sagetrac-mabshoff]

Attachment: trac_5981.patch.gz

[sagetrac-mabshoff]

Description changed:

--- 
+++ 
@@ -1,16 +1,5 @@
-This patch fixes the problem:
+The issue is that Integer(2^40) is evaluated to 0 on 32 bit systems (maybe due to Cython folding constants?). The attached patch uses a long constant instead. Tested to work on 32 and 64 bit boxen.
 
-```
-diff -r 8713e0a599f3 sage/functions/prime_pi.pyx
---- a/sage/functions/prime_pi.pyx	Sun May 03 23:10:56 2009 -0700
-+++ b/sage/functions/prime_pi.pyx	Mon May 04 12:44:03 2009 -0400
-@@ -171,7 +171,7 @@
-             raise ValueError, "mem_mult must be positive"
-         if x < 2:
-             return 0
--        if x > Integer(2**40):
-+        if x > 1099511627776L:
-             raise NotImplementedError, "computation of prime_pi() greater 2**40 not implemented"
-         x += x & 1
-         # m_max is the current sieving value, for prime counting - this value is sqrt(x)
-```
+Cheers,
+
+Michael

[jaapspies]

comment:3

Positive review :)

 ./sage -t  "devel/sage/sage/functions/prime_pi.pyx"
sage -t  "devel/sage/sage/functions/prime_pi.pyx"
     [48.1 s]

----------------------------------------------------------------------
All tests passed!
Total time for all tests: 48.1 seconds


Jaap

[sagetrac-mabshoff]

comment:4

Merged in Sage 3.4.2.

Cheers,

Michael