From: "Ara.T.Howard" <ahoward@...>
Date: 2004-05-13T02:43:56+09:00
Subject: Re: Major Addition Bug?

On Thu, 13 May 2004, Sean O'Dell wrote:

> On Wednesday 12 May 2004 09:53, ts wrote:
> > >>>>> "S" == Sean O'Dell <sean@celsoft.com> writes:
> >
> > S> raise "false" if ((625.91 + 900.00 + 22.00) != 1547.91)
> >
> >  Well, this is well known
> 
> Well known?  I had no idea this bug existed until I wrote a line of code that
> double-checked the arithmetic from a different app.  I have code all over 
> doing simple arithmetic like this.  Ruby can't add 3 simple numbers?  I don't 
> mean to be disproportionately negative, but that shakes my faith more than a 
> little.  It's just simple arithmetic.  How old is this bug?  When is it 
> getting fixed?

i'd say no time soon unless ruby decides to implement it's own floating point
hardware emulator:

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

  int
  main (argc, argv, env)
       int argc;
       char **argv;
       char **env;
  {

    float total = 1547.91;
    float a = 625.91;
    float b = 900.00;
    float c = 22.00;
    float sum;

    sum = a + b + c;

    fprintf (stdout, "total <%f>\n", total);
    fprintf (stdout, "sum <%f>\n", sum);

    return 0;
  }

  ~ > gcc a.c -o a

  ~ > ./a
  total <1547.910034>
  sum <1547.909912>

-a
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