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//===----------------------------------------------------------------------===//
//
// 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;
}