Imported Upstream version 60upstream/60

1 files changed, 52 insertions, 0 deletions

diff --git a/src/pkg/math/floor.go b/src/pkg/math/floor.go
new file mode 100644
index 000000000..babbf645f
--- /dev/null
+++ b/src/pkg/math/floor.go
@@ -0,0 +1,52 @@
+// 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
+}