Bug#210598: libc6.1: Operations on subnormal floating-point numbers generate a floating point exception

[Vincent Lefevre <vincent@vinc17.org>]

Package: libc6.1
Version: 2.3.1-16
Severity: normal

Consider the following program:

#include <stdio.h>
#include <math.h>
int main (void)
{
  double x = ldexp (1.0, -1038);
  fprintf (stderr, "%g\n", x);
  fprintf (stderr, "%g\n", x + 1.0);
  return 0;
}

When compiled and run, I get:

$ ./tst
3.39519e-313
zsh: floating point exception (core dumped)  ./tst

-- System Information
Debian Release: 3.0
Architecture: alpha
Kernel: Linux lepois 2.4.20 #3 Thu Apr 17 10:56:21 CEST 2003 alpha
Locale: LANG=POSIX, LC_CTYPE=en_US.ISO8859-1

Versions of packages libc6.1 depends on:
ii  libdb1-compat                 2.1.3-7    The Berkeley database routines [gl