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139 lines
2.6 KiB
139 lines
2.6 KiB
#pragma once
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/**
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@file
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@brief bit operation
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*/
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#include <assert.h>
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#include <cybozu/inttype.hpp>
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#if (CYBOZU_HOST == CYBOZU_HOST_INTEL)
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#if defined(_WIN32)
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#include <intrin.h>
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#elif defined(__linux__) || defined(__CYGWIN__) || defined(__clang__)
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#include <x86intrin.h>
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#elif defined(__GNUC__)
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#include <emmintrin.h>
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#endif
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#endif
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namespace cybozu {
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namespace bit_op_local {
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template<bool equalTo8>
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struct Tag {};
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// sizeof(T) < 8
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template<>
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struct Tag<false> {
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template<class T>
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static inline int bsf(T x)
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{
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#if defined(_MSC_VER)
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unsigned long out;
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_BitScanForward(&out, x);
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#pragma warning(suppress: 6102)
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return out;
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#else
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return __builtin_ctz(x);
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#endif
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}
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template<class T>
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static inline int bsr(T x)
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{
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#if defined(_MSC_VER)
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unsigned long out;
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_BitScanReverse(&out, x);
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#pragma warning(suppress: 6102)
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return out;
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#else
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return __builtin_clz(x) ^ 0x1f;
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#endif
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}
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};
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// sizeof(T) == 8
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template<>
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struct Tag<true> {
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template<class T>
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static inline int bsf(T x)
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{
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#if defined(_MSC_VER) && defined(_WIN64)
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unsigned long out;
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_BitScanForward64(&out, x);
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#pragma warning(suppress: 6102)
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return out;
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#elif defined(__x86_64__)
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return __builtin_ctzll(x);
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#else
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const uint32_t L = uint32_t(x);
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if (L) return Tag<false>::bsf(L);
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const uint32_t H = uint32_t(x >> 32);
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return Tag<false>::bsf(H) + 32;
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#endif
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}
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template<class T>
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static inline int bsr(T x)
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{
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#if defined(_MSC_VER) && defined(_WIN64)
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unsigned long out;
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_BitScanReverse64(&out, x);
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#pragma warning(suppress: 6102)
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return out;
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#elif defined(__x86_64__)
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return __builtin_clzll(x) ^ 0x3f;
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#else
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const uint32_t H = uint32_t(x >> 32);
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if (H) return Tag<false>::bsr(H) + 32;
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const uint32_t L = uint32_t(x);
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return Tag<false>::bsr(L);
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#endif
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}
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};
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} // bit_op_local
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template<class T>
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int bsf(T x)
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{
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return bit_op_local::Tag<sizeof(T) == 8>::bsf(x);
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}
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template<class T>
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int bsr(T x)
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{
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return bit_op_local::Tag<sizeof(T) == 8>::bsr(x);
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}
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template<class T>
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uint64_t makeBitMask64(T x)
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{
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assert(x < 64);
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return (uint64_t(1) << x) - 1;
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}
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template<class T>
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uint32_t popcnt(T x);
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template<>
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inline uint32_t popcnt<uint32_t>(uint32_t x)
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{
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#if defined(_MSC_VER)
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return static_cast<uint32_t>(_mm_popcnt_u32(x));
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#else
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return static_cast<uint32_t>(__builtin_popcount(x));
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#endif
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}
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template<>
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inline uint32_t popcnt<uint64_t>(uint64_t x)
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{
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#if defined(__x86_64__)
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return static_cast<uint32_t>(__builtin_popcountll(x));
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#elif defined(_WIN64)
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return static_cast<uint32_t>(_mm_popcnt_u64(x));
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#else
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return popcnt<uint32_t>(static_cast<uint32_t>(x)) + popcnt<uint32_t>(static_cast<uint32_t>(x >> 32));
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#endif
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}
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} // cybozu
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