54 lines
1 KiB
C
54 lines
1 KiB
C
/*
|
|
(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
|
|
See the copyright notice in the ACK home directory, in the file "Copyright".
|
|
*/
|
|
|
|
/* $Header$ */
|
|
|
|
/*
|
|
ADD TWO FLOATS - SINGLE (ADF 4)
|
|
*/
|
|
|
|
#include "FP_types.h"
|
|
|
|
_float
|
|
adf4(s2,s1)
|
|
_float s1,s2;
|
|
{
|
|
EXTEND e1,e2;
|
|
int swap = 0;
|
|
|
|
if (s1 == (_float) 0) {
|
|
s1 = s2;
|
|
return s1;
|
|
}
|
|
if (s2 == (_float) 0) {
|
|
return s1;
|
|
}
|
|
extend((_double *)&s1,&e1,sizeof(SINGLE));
|
|
extend((_double *)&s2,&e2,sizeof(SINGLE));
|
|
/* if signs differ do subtraction */
|
|
/* result in e1 */
|
|
if (e1.sign ^ e2.sign) {
|
|
/* set sign of e1 to sign of largest */
|
|
swap = (e2.exp > e1.exp) ? 1 : (e2.exp < e1.exp) ? 0 :
|
|
(e2.m1 > e1.m1 ) ? 1 : 0;
|
|
/* adjust mantissas to equal powers */
|
|
sft_ext(&e1,&e2);
|
|
/* subtract the extended formats */
|
|
if (swap) {
|
|
sub_ext(&e2,&e1);
|
|
e1 = e2;
|
|
}
|
|
else
|
|
sub_ext(&e1,&e2);
|
|
}
|
|
else {
|
|
/* adjust mantissas to equal powers */
|
|
sft_ext(&e1,&e2);
|
|
add_ext(&e1,&e2);
|
|
}
|
|
compact(&e1,(_double *)&s1,sizeof(SINGLE));
|
|
return(s1);
|
|
}
|