43 lines
910 B
Go
43 lines
910 B
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package math
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// Modf returns integer and fractional floating-point numbers
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// that sum to f. Both values have the same sign as f.
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//
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// Special cases are:
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// Modf(±Inf) = ±Inf, NaN
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// Modf(NaN) = NaN, NaN
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func Modf(f float64) (int float64, frac float64) {
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if haveArchModf {
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return archModf(f)
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}
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return modf(f)
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}
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func modf(f float64) (int float64, frac float64) {
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if f < 1 {
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switch {
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case f < 0:
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int, frac = Modf(-f)
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return -int, -frac
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case f == 0:
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return f, f // Return -0, -0 when f == -0
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}
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return 0, f
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}
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x := Float64bits(f)
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e := uint(x>>shift)&mask - bias
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// Keep the top 12+e bits, the integer part; clear the rest.
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if e < 64-12 {
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x &^= 1<<(64-12-e) - 1
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}
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int = Float64frombits(x)
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frac = f - int
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return
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}
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