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Improve the performance of hash_value and operator== in benchmark/uuid.cpp

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Peter Dimov
2022-11-04 17:14:51 +02:00
parent 71b860d6ae
commit d3985f87b3
1 changed files with 12 additions and 3 deletions
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15
benchmark/uuid.cpp
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@ -24,6 +24,7 @@
#include <iostream> #include <iostream>
#include <iomanip> #include <iomanip>
#include <chrono> #include <chrono>
#include <cstring>
using namespace std::chrono_literals; using namespace std::chrono_literals;
@ -55,12 +56,20 @@ struct uuid
inline friend std::size_t hash_value( uuid const& u ) noexcept inline friend std::size_t hash_value( uuid const& u ) noexcept
{ {
return boost::hash_value( u.data ); std::uint64_t low = boost::endian::load_little_u64( u.data + 0 );
std::uint64_t high = boost::endian::load_little_u64( u.data + 8 );
std::size_t r = 0;
boost::hash_combine( r, low );
boost::hash_combine( r, high );
return r;
} }
inline friend bool operator==( uuid const& u1, uuid const& u2 ) noexcept inline friend bool operator==( uuid const& u1, uuid const& u2 ) noexcept
{ {
return std::equal( u1.data + 0, u1.data + 16, u2.data ); return std::memcmp( u1.data, u2.data, 16 ) == 0;
} }
}; };
@ -71,7 +80,7 @@ template<> struct hash< ::uuid >
{ {
std::size_t operator()( uuid const& u ) const noexcept std::size_t operator()( uuid const& u ) const noexcept
{ {
return boost::hash_value( u.data ); return hash_value( u );
} }
}; };