From: | Christof Petig <christof(dot)petig(at)wtal(dot)de> |
---|---|
To: | Lamar Owen <lamar(dot)owen(at)wgcr(dot)org> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgreSQL(dot)org |
Subject: | Re: [HACKERS] Regression tests on intel for 6.5.2 |
Date: | 1999-09-29 15:05:34 |
Message-ID: | 37F22ABD.50997341@wtal.de |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Lamar Owen wrote:
> On Mon, 27 Sep 1999, Tom Lane wrote:
> > which is evidently doing the wrong thing on your platform. What does
> > your man page for exp() say about error return conventions?
>
I checked it twice, I can't find any error in the current sources. I even wrote a test program:
#include <math.h>
#include <stdio.h>
#include <errno.h>
int main()
{ double e;
errno=0;
e=pow(100,200);
if (errno) perror("pow");
if (!finite(e)) puts("!finite\n");
else printf("%f\n",e);
}
Output:
pow: Numerical result out of range
!finite
So both methods seem to work. (finite is a function on glibc-2.1 systems)
Perhaps (strange thoughts come in to my mind ...) the compiler optimizes the function call into a
machine instruction ...
/tmp> cc -O2 -o test test.c -lm
/tmp> ./test
!finite
Looks like this is the case. So (I use gcc-2.95) what to do? Complain about a compiler/library bug
(doesn't set errno)? I would propose another autoconf test. (I could easily do it.)
Christof
PS: I found the offending inline routines in /usr/include/bits/mathinline.h
From | Date | Subject | |
---|---|---|---|
Next Message | Thomas Lockhart | 1999-09-29 15:07:53 | Re: New notices? |
Previous Message | Tom Lane | 1999-09-29 15:04:52 | Re: [HACKERS] Planner drops unreferenced tables --- bug, no? |