mirror of
https://github.com/golang/go
synced 2024-11-26 22:41:23 -07:00
35 lines
585 B
Go
35 lines
585 B
Go
|
// run
|
||
|
|
|
||
|
|
// Copyright 2018 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 main
|
||
|
|
|
||
|
|
import "fmt"
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
want := int32(0x3edae8)
|
||
|
|
got := foo(1)
|
||
|
|
if want != got {
|
||
|
|
panic(fmt.Sprintf("want %x, got %x", want, got))
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func foo(a int32) int32 {
|
||
|
|
return shr1(int32(shr2(int64(0x14ff6e2207db5d1f), int(a))), 4)
|
||
|
|
}
|
||
|
|
|
||
|
|
func shr1(n int32, m int) int32 { return n >> uint(m) }
|
||
|
|
|
||
|
|
func shr2(n int64, m int) int64 {
|
||
|
|
if m < 0 {
|
||
|
|
m = -m
|
||
|
|
}
|
||
|
|
if m >= 64 {
|
||
|
|
return n
|
||
|
|
}
|
||
|
|
|
||
|
|
return n >> uint(m)
|
||
|
|
}
|