Source file src/pkg/math/modf.go

     1	// Copyright 2009 The Go Authors. All rights reserved.
     2	// Use of this source code is governed by a BSD-style
     3	// license that can be found in the LICENSE file.
     4	
     5	package math
     6	
     7	// Modf returns integer and fractional floating-point numbers
     8	// that sum to f. Both values have the same sign as f.
     9	//
    10	// Special cases are:
    11	//	Modf(±Inf) = ±Inf, NaN
    12	//	Modf(NaN) = NaN, NaN
    13	func Modf(f float64) (int float64, frac float64)
    14	
    15	func modf(f float64) (int float64, frac float64) {
    16		if f < 1 {
    17			switch {
    18			case f < 0:
    19				int, frac = Modf(-f)
    20				return -int, -frac
    21			case f == 0:
    22				return f, f // Return -0, -0 when f == -0
    23			}
    24			return 0, f
    25		}
    26	
    27		x := Float64bits(f)
    28		e := uint(x>>shift)&mask - bias
    29	
    30		// Keep the top 12+e bits, the integer part; clear the rest.
    31		if e < 64-12 {
    32			x &^= 1<<(64-12-e) - 1
    33		}
    34		int = Float64frombits(x)
    35		frac = f - int
    36		return
    37	}
    38	

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