source: trunk/minix/lib/ack/float/nrm_ext.fc@ 22

/*
  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
  See the copyright notice in the ACK home directory, in the file "Copyright".
*/

/* $Header: /cvsup/minix/src/lib/ack/float/nrm_ext.fc,v 1.1 2005/10/10 15:27:43 beng Exp $ */

/********************************************************/
/*
        NORMALIZE an EXTENDED FORMAT NUMBER
*/
/********************************************************/

#include "FP_shift.h"
#include "FP_types.h"

void
nrm_ext(e1)
EXTEND  *e1;
{
                /* we assume that the mantissa != 0     */
                /* if it is then just return            */
                /* to let it be a problem elsewhere     */
                /* THAT IS, The exponent is not set to  */
                /* zero. If we don't test here an       */
                /* infinite loop is generated when      */
                /* mantissa is zero                     */

        if ((e1->m1 | e1->m2) == 0L)
                return;

                /* if top word is zero mov low word     */
                /* to top word, adjust exponent value   */
        if (e1->m1 == 0L)       {
                e1->m1 = e1->m2;
                e1->m2 = 0L;
                e1->exp -= 32;
        }
        if ((e1->m1 & NORMBIT) == 0) {
                unsigned long l = ((unsigned long)NORMBIT >> 1);
                int cnt = -1;

                while (! (l & e1->m1)) {
                        l >>= 1;
                        cnt--;
                }
                e1->exp += cnt;
                b64_sft(&(e1->mantissa), cnt);
        }
}