1 files changed, 37 insertions, 0 deletions
diff --git a/src/pkg/math/pow10.go b/src/pkg/math/pow10.go
new file mode 100644
index 000000000..fcdd6e0a1
--- /dev/null
+++ b/src/pkg/math/pow10.go
@@ -0,0 +1,37 @@
+// 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 math
+
+/*
+ * this table might overflow 127-bit exponent representations.
+ * in that case, truncate it after 1.0e38.
+ * it is important to get all one can from this
+ * routine since it is used in atof to scale numbers.
+ * the presumption is that GO converts fp numbers better
+ * than multipication of lower powers of 10.
+ */
+
+var	pow10tab	[70]float64;
+
+// Pow10 returns 10**x, the base-10 exponential of x.
+func Pow10(e int) float64 {
+	if e < 0 {
+		return 1/Pow10(-e);
+	}
+	if e < len(pow10tab) {
+		return pow10tab[e];
+	}
+	m := e/2;
+	return Pow10(m) * Pow10(e-m);
+}
+
+func init() {
+	pow10tab[0] = 1.0e0;
+	pow10tab[1] = 1.0e1;
+	for i:=2; i<len(pow10tab); i++ {
+		m := i/2;
+		pow10tab[i] = pow10tab[m] * pow10tab[i-m];
+	}
+}