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authorJason Downs <downsj@cvs.openbsd.org>1996-07-27 02:52:39 +0000
committerJason Downs <downsj@cvs.openbsd.org>1996-07-27 02:52:39 +0000
commit978f1b8e18efed5647513070f53f269049feb83c (patch)
treece00da25c18405cf3e6847ad3d72d14d363e98b9 /gnu/usr.bin/gcc/f/runtime/libF77/pow_zi.c
parente2ce9843b6a157aadf0700edefbe6d916cb98c57 (diff)
Initial integration of G77.
Please do a make cleandir before rebuilding gcc!
Diffstat (limited to 'gnu/usr.bin/gcc/f/runtime/libF77/pow_zi.c')
-rw-r--r--gnu/usr.bin/gcc/f/runtime/libF77/pow_zi.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/gnu/usr.bin/gcc/f/runtime/libF77/pow_zi.c b/gnu/usr.bin/gcc/f/runtime/libF77/pow_zi.c
new file mode 100644
index 00000000000..167e6acbc6a
--- /dev/null
+++ b/gnu/usr.bin/gcc/f/runtime/libF77/pow_zi.c
@@ -0,0 +1,51 @@
+#include "f2c.h"
+
+#ifdef KR_headers
+VOID pow_zi(p, a, b) /* p = a**b */
+ doublecomplex *p, *a; integer *b;
+#else
+extern void z_div(doublecomplex*, doublecomplex*, doublecomplex*);
+void pow_zi(doublecomplex *p, doublecomplex *a, integer *b) /* p = a**b */
+#endif
+{
+integer n;
+unsigned long u;
+double t;
+doublecomplex x;
+static doublecomplex one = {1.0, 0.0};
+
+n = *b;
+p->r = 1;
+p->i = 0;
+
+if(n == 0)
+ return;
+if(n < 0)
+ {
+ n = -n;
+ z_div(&x, &one, a);
+ }
+else
+ {
+ x.r = a->r;
+ x.i = a->i;
+ }
+
+for(u = n; ; )
+ {
+ if(u & 01)
+ {
+ t = p->r * x.r - p->i * x.i;
+ p->i = p->r * x.i + p->i * x.r;
+ p->r = t;
+ }
+ if(u >>= 1)
+ {
+ t = x.r * x.r - x.i * x.i;
+ x.i = 2 * x.r * x.i;
+ x.r = t;
+ }
+ else
+ break;
+ }
+}