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Allow GetBitMaskSC to be used with mask size equal to type size

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This commit is contained in:
Jonathan G Rennison
2024-06-19 01:17:07 +01:00
parent 0129b2c9d3
commit c76a7f4349
2 changed files with 18 additions and 7 deletions
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9
src/core/bitmath_func.hpp
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@@ -11,6 +11,7 @@
#define BITMATH_FUNC_HPP
#include <bit>
#include <limits>
#include <type_traits>
/**
@@ -192,14 +193,16 @@ constexpr T ToggleBit(T &x, const uint8_t y)
*
* @param start The start bit
* @param count The number of bits
* @pre start + count < sizeof(T) * 8
* @return The bit mask
*/
template <typename T>
constexpr T GetBitMaskSC(const uint8_t start, const uint8_t count)
{
typename std::make_unsigned<T>::type mask = 1;
return (T)(((mask << count) - 1) << start);
using U = typename std::make_unsigned<T>::type;
constexpr uint BIT_WIDTH = std::numeric_limits<U>::digits;
U mask = ((static_cast<U>(1) << (count & (BIT_WIDTH - 1))) - 1) | (count >= BIT_WIDTH ? ~static_cast<U>(0) : 0);
return (T)(mask << start);
}
/**