3458c1e854
* add contract and tests * avoid implicit cast * add test cases * fix test names * modify avarage and add tests * improve signed average formula * fix lint * better average formula * refactor signed average testing * add doc and changelog entry * Update contracts/utils/math/SignedMath.sol Co-authored-by: Francisco Giordano <frangio.1@gmail.com> * remove ceilDiv Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com> Co-authored-by: Francisco Giordano <frangio.1@gmail.com>
33 lines
886 B
Solidity
33 lines
886 B
Solidity
// SPDX-License-Identifier: MIT
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pragma solidity ^0.8.0;
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/**
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* @dev Standard signed math utilities missing in the Solidity language.
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*/
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library SignedMath {
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/**
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* @dev Returns the largest of two signed numbers.
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*/
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function max(int256 a, int256 b) internal pure returns (int256) {
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return a >= b ? a : b;
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}
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/**
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* @dev Returns the smallest of two signed numbers.
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*/
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function min(int256 a, int256 b) internal pure returns (int256) {
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return a < b ? a : b;
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}
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/**
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* @dev Returns the average of two signed numbers without overflow.
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* The result is rounded towards zero.
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*/
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function average(int256 a, int256 b) internal pure returns (int256) {
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// Formula from the book "Hacker's Delight"
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int256 x = (a & b) + ((a ^ b) >> 1);
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return x + (int256(uint256(x) >> 255) & (a ^ b));
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}
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}
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