1 // run 2 3 // Copyright 2018 The Go Authors. All rights reserved. 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file. 6 7 package main 8 9 import ( 10 "math" 11 ) 12 13 type S struct { 14 u int64 15 n int32 16 } 17 18 func F1(f float64) *S { 19 s := f 20 pf := math.Copysign(f, 1) 21 u := math.Floor(pf) 22 return &S{ 23 u: int64(math.Copysign(u, s)), 24 n: int32(math.Copysign((pf-u)*1e9, s)), 25 } 26 } 27 28 func F2(f float64) *S { 29 s := f 30 f = math.Copysign(f, 1) 31 u := math.Floor(f) 32 return &S{ 33 u: int64(math.Copysign(u, s)), 34 n: int32(math.Copysign((f-u)*1e9, s)), 35 } 36 } 37 38 func main() { 39 s1 := F1(-1) 40 s2 := F2(-1) 41 if *s1 != *s2 { 42 println("F1:", s1.u, s1.n) 43 println("F2:", s2.u, s2.n) 44 panic("different") 45 } 46 } 47
