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authorOndřej Surý <ondrej@sury.org>2011-09-13 13:13:40 +0200
committerOndřej Surý <ondrej@sury.org>2011-09-13 13:13:40 +0200
commit5ff4c17907d5b19510a62e08fd8d3b11e62b431d (patch)
treec0650497e988f47be9c6f2324fa692a52dea82e1 /src/pkg/math/modf.go
parent80f18fc933cf3f3e829c5455a1023d69f7b86e52 (diff)
downloadgolang-upstream/60.tar.gz
Imported Upstream version 60upstream/60
Diffstat (limited to 'src/pkg/math/modf.go')
-rw-r--r--src/pkg/math/modf.go33
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
+}