From: Charles Forsyth <forsyth@terzarima.net>
To: 9fans@9fans.net
Subject: Re: [9fans] compiler double bug.
Date: Tue, 1 Dec 2009 16:31:14 +0000 [thread overview]
Message-ID: <615bb2c21f211025b5d9aba799fffe0d@terzarima.net> (raw)
In-Reply-To: <aa38aea3812634942ec2e361c5552c87@brasstown.quanstro.net>
#include <u.h>
#include <libc.h>
void
main(void)
{
double g = 4215866817.;
print("%d\n", (unsigned int)g);
print("%d\n", (unsigned int)g);
exits("");
}
8c r.c
8l r.8
./8.out
-79100479
-79100479
no trap. it generates different code.
(obviously the %d should be %ud in this case, giving
doppio% 8.out
4215866817
4215866817
which looks like the right answer
the cast must be to an unsigned integer.
otherwise the resulting range is signed,
and that's more limited
next prev parent reply other threads:[~2009-12-01 16:31 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <<9987774388a28369b01fa5658da35af9@terzarima.net>
2009-12-01 15:05 ` erik quanstrom
2009-12-01 16:31 ` Charles Forsyth [this message]
[not found] <<d5e75e65219a1207aad92a000119dba0@terzarima.net>
2009-12-02 1:59 ` erik quanstrom
[not found] <<d893fc0b1d0b52a1dd610d7eb14279d3@terzarima.net>
2009-12-01 22:31 ` erik quanstrom
2009-12-01 23:33 ` Charles Forsyth
[not found] <<0232aa110f8423b8381e009b6cda7cef@terzarima.net>
2009-12-01 21:45 ` erik quanstrom
[not found] <<dc10137c2661c11595d2aa2ca370ba45@brasstown.quanstro.net>
2009-12-01 18:53 ` erik quanstrom
[not found] <<a4d2df97e4d97d460ae33ca0800a4060@terzarima.net>
2009-12-01 18:41 ` erik quanstrom
2009-12-01 21:35 ` Charles Forsyth
2009-12-01 22:19 ` Charles Forsyth
[not found] <<615bb2c21f211025b5d9aba799fffe0d@terzarima.net>
2009-12-01 16:39 ` erik quanstrom
2009-12-01 17:02 ` Charles Forsyth
2009-12-01 16:39 ` erik quanstrom
[not found] <<2d42b6b28807634253ba28dc55a96de6@brasstown.quanstro.net>
2009-12-01 8:02 ` erik quanstrom
2009-12-01 9:43 ` Charles Forsyth
2009-12-01 9:45 ` Charles Forsyth
2009-12-01 7:55 erik quanstrom
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