ClickHouse/dbms/src/Functions/isFinite.cpp
2018-09-09 01:04:39 +03:00

45 lines
1.2 KiB
C++

#include <Functions/FunctionNumericPredicate.h>
#include <Functions/FunctionFactory.h>
#include <ext/bit_cast.h>
#include <type_traits>
namespace DB
{
struct IsFiniteImpl
{
/// Better implementation, because isinf, isfinite, isnan are not inlined for unknown reason.
/// Assuming IEEE 754.
/// NOTE gcc 7 doesn't vectorize this loop.
static constexpr auto name = "isFinite";
template <typename T>
static bool execute(const T t)
{
if constexpr (std::is_same_v<T, float>)
return (ext::bit_cast<uint32_t>(t)
& 0b01111111100000000000000000000000)
!= 0b01111111100000000000000000000000;
else if constexpr (std::is_same_v<T, double>)
return (ext::bit_cast<uint64_t>(t)
& 0b0111111111110000000000000000000000000000000000000000000000000000)
!= 0b0111111111110000000000000000000000000000000000000000000000000000;
else
{
(void)t;
return true;
}
}
};
using FunctionIsFinite = FunctionNumericPredicate<IsFiniteImpl>;
void registerFunctionIsFinite(FunctionFactory & factory)
{
factory.registerFunction<FunctionIsFinite>();
}
}