summaryrefslogtreecommitdiff
path: root/Build/source/utils/pmx/pmx-2.6.18/libf2c/z_div.c
blob: b61f03b8efc7dc6bbe7de068eaaf44febcfb76fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
#include "f2c.h"
#ifdef __cplusplus
extern "C" {
#endif

#ifdef KR_headers
extern VOID sig_die();
VOID z_div(c, a, b) doublecomplex *a, *b, *c;
#else
extern void sig_die(char*, int);
void z_div(doublecomplex *c, doublecomplex *a, doublecomplex *b)
#endif
{
	double ratio, den;
	double abr, abi, cr;

	if( (abr = b->r) < 0.)
		abr = - abr;
	if( (abi = b->i) < 0.)
		abi = - abi;
	if( abr <= abi )
		{
		if(abi == 0) {
#ifdef IEEE_COMPLEX_DIVIDE
			if (a->i != 0 || a->r != 0)
				abi = 1.;
			c->i = c->r = abi / abr;
			return;
#else
			sig_die("complex division by zero", 1);
#endif
			}
		ratio = b->r / b->i ;
		den = b->i * (1 + ratio*ratio);
		cr = (a->r*ratio + a->i) / den;
		c->i = (a->i*ratio - a->r) / den;
		}

	else
		{
		ratio = b->i / b->r ;
		den = b->r * (1 + ratio*ratio);
		cr = (a->r + a->i*ratio) / den;
		c->i = (a->i - a->r*ratio) / den;
		}
	c->r = cr;
	}
#ifdef __cplusplus
}
#endif