SVN=114204
diff --git a/src/lib/math/sqrt.go b/src/lib/math/sqrt.go
new file mode 100644
index 0000000..8209a3a
--- /dev/null
+++ b/src/lib/math/sqrt.go
@@ -0,0 +1,64 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sqrt
+
+import sys "sys"
+export sqrt
+
+/*
+ sqrt returns the square root of its floating
+ point argument. Newton's method.
+
+ calls frexp
+*/
+
+func
+sqrt(arg double) double
+{
+ var x, temp double;
+ var exp, i int;
+
+ if sys.isInf(arg, 1) {
+ return arg;
+ }
+
+ if arg <= 0 {
+ if arg < 0 {
+ return sys.NaN();
+ }
+ return 0;
+ }
+
+ exp,x = sys.frexp(arg);
+ for x < 0.5 {
+ x = x*2;
+ exp = exp-1;
+ }
+
+ if exp&1 != 0 {
+ x = x*2;
+ exp = exp-1;
+ }
+ temp = 0.5 * (1+x);
+
+ for exp > 60 {
+ temp = temp * double(1<<30);
+ exp = exp - 60;
+ }
+ for exp < -60 {
+ temp = temp / double(1<<30);
+ exp = exp + 60;
+ }
+ if exp >= 0 {
+ temp = temp * double(1 << (exp/2));
+ } else {
+ temp = temp / double(1 << (-exp/2));
+ }
+
+ for i=0; i<=4; i=i+1 {
+ temp = 0.5*(temp + arg/temp);
+ }
+ return temp;
+}
