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authorRob Pike <r@golang.org>2009-06-09 09:53:44 -0700
committerRob Pike <r@golang.org>2009-06-09 09:53:44 -0700
commit7249ea4df2b4f12a4e7ed446f270cea87e4ffd34 (patch)
tree7032a11d0cac2ae4d3e90f7a189b575b5a50f848 /src/pkg/math/fmod.go
parentacf6ef7a82b3fe61516a1bac4563706552bdf078 (diff)
downloadgolang-7249ea4df2b4f12a4e7ed446f270cea87e4ffd34.tar.gz
mv src/lib to src/pkg
tests: all.bash passes, gobuild still works, godoc still works. R=rsc OCL=30096 CL=30102
Diffstat (limited to 'src/pkg/math/fmod.go')
-rw-r--r--src/pkg/math/fmod.go41
1 files changed, 41 insertions, 0 deletions
diff --git a/src/pkg/math/fmod.go b/src/pkg/math/fmod.go
new file mode 100644
index 000000000..617f5408b
--- /dev/null
+++ b/src/pkg/math/fmod.go
@@ -0,0 +1,41 @@
+// 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
+
+import "math"
+
+/*
+ * floating-point mod func without infinity or NaN checking
+ */
+
+// Fmod returns the floating-point remainder of x/y.
+func Fmod(x, y float64) float64 {
+ if y == 0 {
+ return x;
+ }
+ if y < 0 {
+ y = -y;
+ }
+
+ yfr, yexp := Frexp(y);
+ sign := false;
+ r := x;
+ if x < 0 {
+ r = -x;
+ sign = true;
+ }
+
+ for r >= y {
+ rfr, rexp := Frexp(r);
+ if rfr < yfr {
+ rexp = rexp - 1;
+ }
+ r = r - Ldexp(y, rexp-yexp);
+ }
+ if sign {
+ r = -r;
+ }
+ return r;
+}