ClickHouse/src/Functions/isFinite.cpp
Robert Schulze 9c066e964d
Less use of CH-specific bit_cast()
Converted usage of CH-custom bit_cast to std::bit_cast if possible, i.e.
when
  sizeof(From) == sizeof(To).
(The CH-custom bit_cast is able to deal with sizeof(From) != sizeof(To).)

Motivation for this came from #42847 where it is not clear how the
internal bit_cast should behave on big endian systems, so we better
avoid that situation as much as possible.
2022-11-04 15:52:48 +00:00

47 lines
1.1 KiB
C++

#include <Functions/FunctionNumericPredicate.h>
#include <Functions/FunctionFactory.h>
#include <type_traits>
namespace DB
{
namespace
{
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 (std::bit_cast<uint32_t>(t)
& 0b01111111100000000000000000000000)
!= 0b01111111100000000000000000000000;
else if constexpr (std::is_same_v<T, double>)
return (std::bit_cast<uint64_t>(t)
& 0b0111111111110000000000000000000000000000000000000000000000000000)
!= 0b0111111111110000000000000000000000000000000000000000000000000000;
else
{
(void)t;
return true;
}
}
};
using FunctionIsFinite = FunctionNumericPredicate<IsFiniteImpl>;
}
REGISTER_FUNCTION(IsFinite)
{
factory.registerFunction<FunctionIsFinite>();
}
}