Re: [BUGS] BUG #2846: inconsistent and confusing handling of underflows, - Mailing list pgsql-patches

On 12/27/2006 03:23 PM, Bruce Momjian wrote:
> Are you sure?  As I remember, computation automatically upgrades to
> 'double'.  See this program and output:

This is platform- and compiler- dependent:

~>uname -a
Linux rklinux 2.6.15-27-amd64-generic #1 SMP PREEMPT Fri Dec 8 17:50:54 UTC 2006 x86_64 GNU/Linux
~>gcc --version
gcc (GCC) 4.3.0 20061213 (experimental)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

~>cat test.c
#include <stdio.h>
#include <stdlib.h>

int
main(int argc, char *argv[])
{
    float a = 1e30, b = 1e30;
    double c;

    c = a * b;

    printf("%e\n", c);
    return 0;
}
~>gcc test.c
~>./a.out
inf
~>gcc -march=i386 -m32 test.c
~>./a.out
1.000000e+60

Roman