summaryrefslogtreecommitdiff
path: root/gnu/egcs/libf2c/libF77/c_div.c
diff options
context:
space:
mode:
Diffstat (limited to 'gnu/egcs/libf2c/libF77/c_div.c')
-rw-r--r--gnu/egcs/libf2c/libF77/c_div.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/gnu/egcs/libf2c/libF77/c_div.c b/gnu/egcs/libf2c/libF77/c_div.c
new file mode 100644
index 00000000000..ac963079ba2
--- /dev/null
+++ b/gnu/egcs/libf2c/libF77/c_div.c
@@ -0,0 +1,37 @@
+#include "f2c.h"
+
+#ifdef KR_headers
+extern VOID sig_die();
+VOID c_div(c, a, b)
+complex *a, *b, *c;
+#else
+extern void sig_die(char*,int);
+void c_div(complex *c, complex *a, complex *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)
+ sig_die("complex division by zero", 1);
+ ratio = (double)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 = (double)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;
+ }