1 | /* |
2 | * Copyright 2017 Uber Technologies, 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 | /** @file mathExtensions.c |
17 | * @brief Math functions that should've been in math.h but aren't |
18 | */ |
19 | |
20 | #include "mathExtensions.h" |
21 | |
22 | /** |
23 | * _ipow does integer exponentiation efficiently. Taken from StackOverflow. |
24 | * |
25 | * @param base the integer base |
26 | * @param exp the integer exponent |
27 | * |
28 | * @return the exponentiated value |
29 | */ |
30 | int _ipow(int base, int exp) { |
31 | int result = 1; |
32 | while (exp) { |
33 | if (exp & 1) result *= base; |
34 | exp >>= 1; |
35 | base *= base; |
36 | } |
37 | |
38 | return result; |
39 | } |
40 | |