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 "fmt" 10 11 func main() { 12 want := int32(0x3edae8) 13 got := foo(1) 14 if want != got { 15 panic(fmt.Sprintf("want %x, got %x", want, got)) 16 } 17 } 18 19 func foo(a int32) int32 { 20 return shr1(int32(shr2(int64(0x14ff6e2207db5d1f), int(a))), 4) 21 } 22 23 func shr1(n int32, m int) int32 { return n >> uint(m) } 24 25 func shr2(n int64, m int) int64 { 26 if m < 0 { 27 m = -m 28 } 29 if m >= 64 { 30 return n 31 } 32 33 return n >> uint(m) 34 } 35
