gcc/libgo/go/math/floor.go

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// Copyright 2009-2010 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
// Floor returns the greatest integer value less than or equal to x.
//
// Special cases are:
// Floor(±0) = ±0
// Floor(±Inf) = ±Inf
// Floor(NaN) = NaN
//extern floor
func libc_floor(float64) float64
func Floor(x float64) float64 {
return libc_floor(x)
}
func floor(x float64) float64 {
if x == 0 || IsNaN(x) || IsInf(x, 0) {
return x
}
if x < 0 {
d, fract := Modf(-x)
if fract != 0.0 {
d = d + 1
}
return -d
}
d, _ := Modf(x)
return d
}
// Ceil returns the least integer value greater than or equal to x.
//
// Special cases are:
// Ceil(±0) = ±0
// Ceil(±Inf) = ±Inf
// Ceil(NaN) = NaN
//extern ceil
func libc_ceil(float64) float64
func Ceil(x float64) float64 {
return libc_ceil(x)
}
func ceil(x float64) float64 {
return -Floor(-x)
}
// Trunc returns the integer value of x.
//
// Special cases are:
// Trunc(±0) = ±0
// Trunc(±Inf) = ±Inf
// Trunc(NaN) = NaN
func Trunc(x float64) float64 {
return trunc(x)
}
func trunc(x float64) float64 {
if x == 0 || IsNaN(x) || IsInf(x, 0) {
return x
}
d, _ := Modf(x)
return d
}