| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| |
| // Assumption: minValue < maxValue |
| // Assumption: minValue <= rhs <= maxValue |
| // Assumption: minValue <= lhs <= maxValue |
| // Assumption: minValue >= 0 |
| template <typename T, T minValue, T maxValue> |
| T euclidian_addition(T rhs, T lhs) |
| { |
| const T modulus = maxValue - minValue + 1; |
| T ret = rhs + lhs; |
| if (ret > maxValue) |
| ret -= modulus; |
| return ret; |
| } |
| |
| // Assumption: minValue < maxValue |
| // Assumption: minValue <= rhs <= maxValue |
| // Assumption: minValue <= lhs <= maxValue |
| // Assumption: minValue >= 0 |
| template <typename T, T minValue, T maxValue> |
| T euclidian_subtraction(T lhs, T rhs) |
| { |
| const T modulus = maxValue - minValue + 1; |
| T ret = lhs - rhs; |
| if (ret < minValue) |
| ret += modulus; |
| if (ret > maxValue) // this can happen if T is unsigned |
| ret += modulus; |
| return ret; |
| } |