mirror of https://github.com/bsnes-emu/bsnes.git
20 lines
629 B
C++
20 lines
629 B
C++
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#pragma once
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#include <nall/range.hpp>
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namespace nall {
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//counting sort by powers of two: used to implement radix sort
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template<uint Bits, uint Shift, typename T>
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auto counting_sort(T* output, const T* input, uint size) -> void {
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static_assert(Bits >= 1 && Bits <= 20, "must be between 1 and 20 bits");
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enum : uint { Base = 1 << Bits, Mask = Base - 1 };
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uint64_t count[Base] = {}, last = 0;
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for(uint n : range(size)) ++count[(input[n] >> Shift) & Mask];
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for(uint n : range(Base)) last += count[n], count[n] = last - count[n];
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for(uint n : range(size)) output[count[(input[n] >> Shift) & Mask]++] = input[n];
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}
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}
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