bin/157177: primes(1) prints non-prime for numbers > 2^32

Robert Lorentz robert.lorentz at
Tue Jun 14 04:00:24 UTC 2011

The following reply was made to PR bin/157177; it has been noted by GNATS.

From: Robert Lorentz <robert.lorentz at>
To: bug-followup at,
 kcwu at
Subject: Re: bin/157177: primes(1) prints non-prime for numbers &gt; 2^32
Date: Mon, 13 Jun 2011 23:29:33 -0400

 I regression tested this on FreeBSD 8.2-RELEASE against FreeBSD =
 9.0-CURRENT r221981, using primegen-0.97 on amd64 platform and came up =
 with some interesting results.
 First off, from primes(1) man page, syntax is:
 primes [ low [high] ]
 So your bc line effectively says:
 primes 4294967296=20
 Where low =3D 4294967296 and high is not explicitly stated.  According =
 to the man page high defaults to 1000000000 where the last prime =
 possible is 999999937.  Since 1,000,000,000 < 4,294,967,296, the correct =
 output of "primes 4294967296" should be nothing.
 In FreeBSD 8.2-RELEASE, primes correctly does output nothing.
 However on FreeBSD 9.0-CURRENT, primes incorrectly prints primes =
 starting at 4,294,967,296 and seems to go forever (not sure where it =
 will stop).  This is contrary to what the manual page says and is a =
 Your original problem I did regression test and confirm to be working in =
 8.2-RELEASE and broken in 9.0-CURRENT.  I isolated one of your examples =
 primes 4295360520 4295360522 | xargs -n 1 factor
 On FreeBSD 9.0-CURRENT: 4295360521: 65539 65539
 On FreeBSD 8.2-RELEASE: No output=20
 On FreeBSD 9.0-CURRENT I debugged the source in =
 /usr/ports/math/primegen/work/primegen-0.97 a bit and realized that if I =
 ran the compiled version in =
 /usr/ports/math/primegen/work/primegen-0.97/primes I got the correct =
 expected results.  However, if I run the installed version in =
 /usr/games/primes, I get the incorrect results.  The binaries in those =
 two places aren't the same (verified using md5). =20
 This appears to be an issue with the port building, probably building in =
 32 bit.  If the inputs to primes are interpreted as 32bit then a "low" =
 of (2^32 + 1) is interpreted as 1, therefore being less than 1000000000, =
 therefore the code would continue to generate primes, and if this is the =
 case then I wouldn't be surprised that the prime generation code also =
 would misbehave.

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