summaryrefslogtreecommitdiff
path: root/libgo/go/math/floor.go
diff options
context:
space:
mode:
Diffstat (limited to 'libgo/go/math/floor.go')
-rw-r--r--libgo/go/math/floor.go53
1 files changed, 53 insertions, 0 deletions
diff --git a/libgo/go/math/floor.go b/libgo/go/math/floor.go
new file mode 100644
index 000000000..b22b94ad6
--- /dev/null
+++ b/libgo/go/math/floor.go
@@ -0,0 +1,53 @@
+// Copyright 2009-2010 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
+
+
+// Floor returns the greatest integer value less than or equal to x.
+//
+// Special cases are:
+// Floor(+Inf) = +Inf
+// Floor(-Inf) = -Inf
+// Floor(NaN) = NaN
+func Floor(x float64) float64 {
+ // TODO(rsc): Remove manual inlining of IsNaN, IsInf
+ // when compiler does it for us
+ if x == 0 || x != x || x > MaxFloat64 || x < -MaxFloat64 { // x == 0 || IsNaN(x) || IsInf(x, 0)
+ return x
+ }
+ if x < 0 {
+ d, fract := Modf(-x)
+ if fract != 0.0 {
+ d = d + 1
+ }
+ return -d
+ }
+ d, _ := Modf(x)
+ return d
+}
+
+// Ceil returns the least integer value greater than or equal to x.
+//
+// Special cases are:
+// Ceil(+Inf) = +Inf
+// Ceil(-Inf) = -Inf
+// Ceil(NaN) = NaN
+func Ceil(x float64) float64 { return -Floor(-x) }
+
+// Trunc returns the integer value of x.
+//
+// Special cases are:
+// Trunc(+Inf) = +Inf
+// Trunc(-Inf) = -Inf
+// Trunc(NaN) = NaN
+func Trunc(x float64) float64 {
+ // TODO(rsc): Remove manual inlining of IsNaN, IsInf
+ // when compiler does it for us
+ if x == 0 || x != x || x > MaxFloat64 || x < -MaxFloat64 { // x == 0 || IsNaN(x) || IsInf(x, 0)
+ return x
+ }
+ d, _ := Modf(x)
+ return d
+}