| /* |
| * Copyright 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef A_UTILS_H_ |
| |
| #define A_UTILS_H_ |
| |
| /* ============================ math templates ============================ */ |
| |
| /* T must be integer type, den must not be 0 */ |
| template<class T> |
| inline static const T divRound(const T &nom, const T &den) { |
| if ((nom >= 0) ^ (den >= 0)) { |
| return (nom - den / 2) / den; |
| } else { |
| return (nom + den / 2) / den; |
| } |
| } |
| |
| /* == ceil(nom / den). T must be integer type, den must not be 0 */ |
| template<class T> |
| inline static const T divUp(const T &nom, const T &den) { |
| if (den < 0) { |
| return (nom < 0 ? nom + den + 1 : nom) / den; |
| } else { |
| return (nom < 0 ? nom : nom + den - 1) / den; |
| } |
| } |
| |
| /* == ceil(nom / den) * den. T must be integer type, alignment must be positive power of 2 */ |
| template<class T, class U> |
| inline static const T align(const T &nom, const U &den) { |
| return (nom + (T)(den - 1)) & (T)~(den - 1); |
| } |
| |
| template<class T> |
| inline static T abs(const T &a) { |
| return a < 0 ? -a : a; |
| } |
| |
| template<class T> |
| inline static const T &min(const T &a, const T &b) { |
| return a < b ? a : b; |
| } |
| |
| template<class T> |
| inline static const T &max(const T &a, const T &b) { |
| return a > b ? a : b; |
| } |
| |
| template<class T> |
| void ENSURE_UNSIGNED_TYPE() { |
| T TYPE_MUST_BE_UNSIGNED[(T)-1 < 0 ? -1 : 0] __unused; |
| } |
| |
| // needle is in range [hayStart, hayStart + haySize) |
| template<class T, class U> |
| __attribute__((no_sanitize("integer"))) |
| inline static bool isInRange(const T &hayStart, const U &haySize, const T &needle) { |
| ENSURE_UNSIGNED_TYPE<U>(); |
| return (T)(hayStart + haySize) >= hayStart && needle >= hayStart && (U)(needle - hayStart) < haySize; |
| } |
| |
| // [needleStart, needleStart + needleSize) is in range [hayStart, hayStart + haySize) |
| template<class T, class U> |
| __attribute__((no_sanitize("integer"))) |
| inline static bool isInRange( |
| const T &hayStart, const U &haySize, const T &needleStart, const U &needleSize) { |
| ENSURE_UNSIGNED_TYPE<U>(); |
| return isInRange(hayStart, haySize, needleStart) |
| && (T)(needleStart + needleSize) >= needleStart |
| && (U)(needleStart + needleSize - hayStart) <= haySize; |
| } |
| |
| /* T must be integer type, period must be positive */ |
| template<class T> |
| inline static T periodicError(const T &val, const T &period) { |
| T err = abs(val) % period; |
| return (err < (period / 2)) ? err : (period - err); |
| } |
| |
| #endif // A_UTILS_H_ |