1 //
2 // Copyright 2024 CloudWeGo Authors
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 expr
18 19 import (
20 "fmt"
21 )
22 23 func idiv(v int64, d int64) (int64, error) {
24 if d != 0 {
25 return v / d, nil
26 } else {
27 return 0, newRuntimeError("division by zero")
28 }
29 }
30 31 func imod(v int64, d int64) (int64, error) {
32 if d != 0 {
33 return v % d, nil
34 } else {
35 return 0, newRuntimeError("division by zero")
36 }
37 }
38 39 func ipow(v int64, e int64) (int64, error) {
40 mul := v
41 ret := int64(1)
42 43 /* value must be 0 or positive */
44 if v < 0 {
45 return 0, newRuntimeError(fmt.Sprintf("negative base value: %d", v))
46 }
47 48 /* exponent must be non-negative */
49 if e < 0 {
50 return 0, newRuntimeError(fmt.Sprintf("negative exponent: %d", e))
51 }
52 53 /* fast power first round */
54 if (e & 1) != 0 {
55 ret *= mul
56 }
57 58 /* fast power remaining rounds */
59 for e >>= 1; e != 0; e >>= 1 {
60 if mul *= mul; (e & 1) != 0 {
61 ret *= mul
62 }
63 }
64 65 /* all done */
66 return ret, nil
67 }
68