diff options
author | Russ Cox <rsc@golang.org> | 2014-09-08 00:08:51 -0400 |
---|---|---|
committer | Russ Cox <rsc@golang.org> | 2014-09-08 00:08:51 -0400 |
commit | 8528da672cc093d4dd06732819abc1f7b6b5a46e (patch) | |
tree | 334be80d4a4c85b77db6f6fdb67cbf0528cba5f5 /src/math/nextafter.go | |
parent | 73bcb69f272cbf34ddcc9daa56427a8683b5a95d (diff) | |
download | go-8528da672cc093d4dd06732819abc1f7b6b5a46e.tar.gz |
build: move package sources from src/pkg to src
Preparation was in CL 134570043.
This CL contains only the effect of 'hg mv src/pkg/* src'.
For more about the move, see golang.org/s/go14nopkg.
Diffstat (limited to 'src/math/nextafter.go')
-rw-r--r-- | src/math/nextafter.go | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/math/nextafter.go b/src/math/nextafter.go new file mode 100644 index 000000000..bbb139986 --- /dev/null +++ b/src/math/nextafter.go @@ -0,0 +1,47 @@ +// Copyright 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 + +// Nextafter32 returns the next representable float32 value after x towards y. +// Special cases: +// Nextafter32(x, x) = x +// Nextafter32(NaN, y) = NaN +// Nextafter32(x, NaN) = NaN +func Nextafter32(x, y float32) (r float32) { + switch { + case IsNaN(float64(x)) || IsNaN(float64(y)): // special case + r = float32(NaN()) + case x == y: + r = x + case x == 0: + r = float32(Copysign(float64(Float32frombits(1)), float64(y))) + case (y > x) == (x > 0): + r = Float32frombits(Float32bits(x) + 1) + default: + r = Float32frombits(Float32bits(x) - 1) + } + return +} + +// Nextafter returns the next representable float64 value after x towards y. +// Special cases: +// Nextafter64(x, x) = x +// Nextafter64(NaN, y) = NaN +// Nextafter64(x, NaN) = NaN +func Nextafter(x, y float64) (r float64) { + switch { + case IsNaN(x) || IsNaN(y): // special case + r = NaN() + case x == y: + r = x + case x == 0: + r = Copysign(Float64frombits(1), y) + case (y > x) == (x > 0): + r = Float64frombits(Float64bits(x) + 1) + default: + r = Float64frombits(Float64bits(x) - 1) + } + return +} |