Tail calls and floating-point types (was Re: remove unneeded fold-converts)

[Richard Henderson]

On Thu, Sep 09, 2004 at 04:34:21PM +0100, Richard Sandiford wrote:
> + /* Tail call optimizations would convert func() into the moral
> equivalent of:
> + 
> +        double acc = 0.0;
> +        for (int i = 0; i < n; i++)
> + 	 acc += d;
> +        return acc;
> + 
> +    which mishandles the case where 'd' is -0.  They also initialised 'acc'
> +    to a zero int rather than a zero double.  */
> + 
> + double func (double d, int n)
> + {
> +   if (n == 0)
> +     return d;
> +   else
> +     return d + func (d, n - 1);

Whee.  That's nifty.

Yeah, a check for HONOR_SIGNED_ZEROS would do the trick.


r~