Re: Re: Has this fp fix been considered? - ADDENDUM

I don't quite understand. Can you give us a few examples, how they are handled by PHP today and how they would be handled by your code. I'll start off: 0.9+0.1 0.9+0.0000001 8/10.0 + 0.2 I'm sure you know of juicier examples :) Andi At 02:33 PM 6/26/2002 +0100, George Whiffen wrote:

Oops, I forgot to sort out the catastrophic loss of precision on differences. So that means that on add and subtract we need to use the maximum fabs value of the operands to calculate the rounding trather than the result itself: So redecimalize() becomes: double redecimalize(double dval,double rval) {

    double f;
    if (dval == 0)

{

      return dval;

} f = pow(10.0, (double) DBL_DIG - (1 + floor(log10(fabs(rval))))); return (double) (rint(dval*f))/f; } and add_function, div_function need to look more like: double dop1,dop2,rval; .... if ((op1->type == IS_DOUBLE || op1->type == IS_LONG) && (op2->type == IS_LONG || op2->type == IS_DOUBLE)) { dop1 = (op1->type == IS_LONG) ? ((double) op1->value.lval):op1->value.dval; dop2 = (op2->type == IS_LONG) ? ((double) op2->value.lval):op2->value.dval; result->value.dval = dop1 - dop2; rval = fabs(dop1) > fabs(dop2) ? dop1:dop2; result->value.dval = redecimalize(result->value.dval,rval); result->type = IS_DOUBLE; return SUCCESS; } The calls to redecimalize on mul_function,div_function simply pass the result twice e.g. result->value.dval = redecimalize(result->value.dval,result->value.dval); There's no significant impact on performance. George -- PHP Development Mailing List <http://www.php.net/> To unsubscribe, visit: http://www.php.net/unsub.php