1 /*
2 * Copyright 2021 ByteDance Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 17 package rt
18 19 const (
20 MinInt48 int64 = -(1 << 47)
21 MaxInt48 int64 = +(1 << 47) - 1
22 )
23 24 func PackInt(v int) uint64 {
25 if u := uint64(v); int64(v) < MinInt48 || int64(v) > MaxInt48 {
26 panic("int48 out of range")
27 } else {
28 return ((u >> 63) << 47) | (u & 0x00007fffffffffff)
29 }
30 }
31 32 func UnpackInt(v uint64) int {
33 v &= 0x0000ffffffffffff
34 v |= (v >> 47) * (0xffff << 48)
35 return int(v)
36 }
37