diff options
author | Ondřej Surý <ondrej@sury.org> | 2011-09-13 13:13:40 +0200 |
---|---|---|
committer | Ondřej Surý <ondrej@sury.org> | 2011-09-13 13:13:40 +0200 |
commit | 5ff4c17907d5b19510a62e08fd8d3b11e62b431d (patch) | |
tree | c0650497e988f47be9c6f2324fa692a52dea82e1 /src/pkg/math/modf.go | |
parent | 80f18fc933cf3f3e829c5455a1023d69f7b86e52 (diff) | |
download | golang-upstream/60.tar.gz |
Imported Upstream version 60upstream/60
Diffstat (limited to 'src/pkg/math/modf.go')
-rw-r--r-- | src/pkg/math/modf.go | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/pkg/math/modf.go b/src/pkg/math/modf.go new file mode 100644 index 000000000..315174b70 --- /dev/null +++ b/src/pkg/math/modf.go @@ -0,0 +1,33 @@ +// 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 + +// Modf returns integer and fractional floating-point numbers +// that sum to f. Both values have the same sign as f. +// +// Special cases are: +// Modf(+Inf) = +Inf, NaN +// Modf(-Inf) = -Inf, NaN +// Modf(NaN) = NaN, NaN +func Modf(f float64) (int float64, frac float64) { + if f < 1 { + if f < 0 { + int, frac = Modf(-f) + return -int, -frac + } + return 0, f + } + + x := Float64bits(f) + e := uint(x>>shift)&mask - bias + + // Keep the top 12+e bits, the integer part; clear the rest. + if e < 64-12 { + x &^= 1<<(64-12-e) - 1 + } + int = Float64frombits(x) + frac = f - int + return +} |