1 files changed, 29 insertions, 0 deletions
diff --git a/gnu/egcs/libf2c/libF77/z_sqrt.c b/gnu/egcs/libf2c/libF77/z_sqrt.c
new file mode 100644
index 00000000000..c04e8f0a1a7
--- /dev/null
+++ b/gnu/egcs/libf2c/libF77/z_sqrt.c
@@ -0,0 +1,29 @@
+#include "f2c.h"
+
+#ifdef KR_headers
+double sqrt(), f__cabs();
+VOID z_sqrt(r, z) doublecomplex *r, *z;
+#else
+#undef abs
+#include "math.h"
+extern double f__cabs(double, double);
+void z_sqrt(doublecomplex *r, doublecomplex *z)
+#endif
+{
+	double mag, zi = z->i, zr = z->r;
+
+	if( (mag = f__cabs(zr, zi)) == 0.)
+		r->r = r->i = 0.;
+	else if(zr > 0)
+		{
+		r->r = sqrt(0.5 * (mag + zr) );
+		r->i = zi / r->r / 2;
+		}
+	else
+		{
+		r->i = sqrt(0.5 * (mag - zr) );
+		if(zi < 0)
+			r->i = - r->i;
+		r->r = zi / r->i / 2;
+		}
+	}