39 lines
1.2 KiB
C++
39 lines
1.2 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// Assumption: minValue < maxValue
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// Assumption: minValue <= rhs <= maxValue
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// Assumption: minValue <= lhs <= maxValue
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// Assumption: minValue >= 0
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template <typename T, T minValue, T maxValue>
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T euclidian_addition(T rhs, T lhs)
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{
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const T modulus = maxValue - minValue + 1;
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T ret = rhs + lhs;
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if (ret > maxValue)
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ret -= modulus;
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return ret;
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}
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// Assumption: minValue < maxValue
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// Assumption: minValue <= rhs <= maxValue
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// Assumption: minValue <= lhs <= maxValue
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// Assumption: minValue >= 0
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template <typename T, T minValue, T maxValue>
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T euclidian_subtraction(T lhs, T rhs)
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{
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const T modulus = maxValue - minValue + 1;
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T ret = lhs - rhs;
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if (ret < minValue)
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ret += modulus;
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if (ret > maxValue) // this can happen if T is unsigned
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ret += modulus;
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return ret;
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}
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