ClickHouse/src/Functions/modulo.cpp

113 lines
4.4 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionBinaryArithmetic.h>
#if defined(__SSE2__)
# define LIBDIVIDE_SSE2 1
#endif
#include <libdivide.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_DIVISION;
}
namespace
{
/// Optimizations for integer modulo by a constant.
template <typename A, typename B>
struct ModuloByConstantImpl
: BinaryOperation<A, B, ModuloImpl<A, B>>
{
using ResultType = typename ModuloImpl<A, B>::ResultType;
static const constexpr bool allow_fixed_string = false;
static NO_INLINE void vectorConstant(const A * __restrict src, B b, ResultType * __restrict dst, size_t size)
{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-compare"
/// Modulo with too small divisor.
if (unlikely((std::is_signed_v<B> && b == -1) || b == 1))
{
for (size_t i = 0; i < size; ++i)
dst[i] = 0;
return;
}
/// Modulo with too large divisor.
if (unlikely(b > std::numeric_limits<A>::max()
|| (std::is_signed_v<A> && std::is_signed_v<B> && b < std::numeric_limits<A>::lowest())))
{
for (size_t i = 0; i < size; ++i)
dst[i] = src[i];
return;
}
#pragma GCC diagnostic pop
if (unlikely(static_cast<A>(b) == 0))
throw Exception("Division by zero", ErrorCodes::ILLEGAL_DIVISION);
libdivide::divider<A> divider(b);
/// Here we failed to make the SSE variant from libdivide give an advantage.
if (b & (b - 1))
{
for (size_t i = 0; i < size; ++i)
dst[i] = src[i] - (src[i] / divider) * b; /// NOTE: perhaps, the division semantics with the remainder of negative numbers is not preserved.
}
else
{
// gcc libdivide doesn't work well for pow2 division
auto mask = b - 1;
for (size_t i = 0; i < size; ++i)
dst[i] = src[i] & mask;
}
}
};
}
/** Specializations are specified for dividing numbers of the type UInt64 and UInt32 by the numbers of the same sign.
* Can be expanded to all possible combinations, but more code is needed.
*/
template <> struct BinaryOperationImpl<UInt64, UInt8, ModuloImpl<UInt64, UInt8>> : ModuloByConstantImpl<UInt64, UInt8> {};
template <> struct BinaryOperationImpl<UInt64, UInt16, ModuloImpl<UInt64, UInt16>> : ModuloByConstantImpl<UInt64, UInt16> {};
template <> struct BinaryOperationImpl<UInt64, UInt32, ModuloImpl<UInt64, UInt32>> : ModuloByConstantImpl<UInt64, UInt32> {};
template <> struct BinaryOperationImpl<UInt64, UInt64, ModuloImpl<UInt64, UInt64>> : ModuloByConstantImpl<UInt64, UInt64> {};
template <> struct BinaryOperationImpl<UInt32, UInt8, ModuloImpl<UInt32, UInt8>> : ModuloByConstantImpl<UInt32, UInt8> {};
template <> struct BinaryOperationImpl<UInt32, UInt16, ModuloImpl<UInt32, UInt16>> : ModuloByConstantImpl<UInt32, UInt16> {};
template <> struct BinaryOperationImpl<UInt32, UInt32, ModuloImpl<UInt32, UInt32>> : ModuloByConstantImpl<UInt32, UInt32> {};
template <> struct BinaryOperationImpl<UInt32, UInt64, ModuloImpl<UInt32, UInt64>> : ModuloByConstantImpl<UInt32, UInt64> {};
template <> struct BinaryOperationImpl<Int64, Int8, ModuloImpl<Int64, Int8>> : ModuloByConstantImpl<Int64, Int8> {};
template <> struct BinaryOperationImpl<Int64, Int16, ModuloImpl<Int64, Int16>> : ModuloByConstantImpl<Int64, Int16> {};
template <> struct BinaryOperationImpl<Int64, Int32, ModuloImpl<Int64, Int32>> : ModuloByConstantImpl<Int64, Int32> {};
template <> struct BinaryOperationImpl<Int64, Int64, ModuloImpl<Int64, Int64>> : ModuloByConstantImpl<Int64, Int64> {};
template <> struct BinaryOperationImpl<Int32, Int8, ModuloImpl<Int32, Int8>> : ModuloByConstantImpl<Int32, Int8> {};
template <> struct BinaryOperationImpl<Int32, Int16, ModuloImpl<Int32, Int16>> : ModuloByConstantImpl<Int32, Int16> {};
template <> struct BinaryOperationImpl<Int32, Int32, ModuloImpl<Int32, Int32>> : ModuloByConstantImpl<Int32, Int32> {};
template <> struct BinaryOperationImpl<Int32, Int64, ModuloImpl<Int32, Int64>> : ModuloByConstantImpl<Int32, Int64> {};
struct NameModulo { static constexpr auto name = "modulo"; };
using FunctionModulo = BinaryArithmeticOverloadResolver<ModuloImpl, NameModulo, false>;
void registerFunctionModulo(FunctionFactory & factory)
{
factory.registerFunction<FunctionModulo>();
factory.registerAlias("mod", "modulo", FunctionFactory::CaseInsensitive);
}
}