ClickHouse/dbms/src/Functions/intDiv.cpp
2019-01-04 15:10:00 +03:00

105 lines
4.4 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionBinaryArithmetic.h>
#include <Functions/intDiv.h>
#ifdef __SSE2__
#define LIBDIVIDE_USE_SSE2 1
#endif
#include <libdivide.h>
namespace DB
{
/// Optimizations for integer division by a constant.
template <typename A, typename B>
struct DivideIntegralByConstantImpl
: BinaryOperationImplBase<A, B, DivideIntegralImpl<A, B>>
{
using ResultType = typename DivideIntegralImpl<A, B>::ResultType;
static void vector_constant(const PaddedPODArray<A> & a, B b, PaddedPODArray<ResultType> & c)
{
if (unlikely(b == 0))
throw Exception("Division by zero", ErrorCodes::ILLEGAL_DIVISION);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-compare"
if (unlikely(std::is_signed_v<B> && b == -1))
{
size_t size = a.size();
for (size_t i = 0; i < size; ++i)
c[i] = -c[i];
return;
}
#pragma GCC diagnostic pop
libdivide::divider<A> divider(b);
size_t size = a.size();
const A * a_pos = a.data();
const A * a_end = a_pos + size;
ResultType * c_pos = c.data();
#ifdef __SSE2__
static constexpr size_t values_per_sse_register = 16 / sizeof(A);
const A * a_end_sse = a_pos + size / values_per_sse_register * values_per_sse_register;
while (a_pos < a_end_sse)
{
_mm_storeu_si128(reinterpret_cast<__m128i *>(c_pos),
_mm_loadu_si128(reinterpret_cast<const __m128i *>(a_pos)) / divider);
a_pos += values_per_sse_register;
c_pos += values_per_sse_register;
}
#endif
while (a_pos < a_end)
{
*c_pos = *a_pos / divider;
++a_pos;
++c_pos;
}
}
};
/** 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, DivideIntegralImpl<UInt64, UInt8>> : DivideIntegralByConstantImpl<UInt64, UInt8> {};
template <> struct BinaryOperationImpl<UInt64, UInt16, DivideIntegralImpl<UInt64, UInt16>> : DivideIntegralByConstantImpl<UInt64, UInt16> {};
template <> struct BinaryOperationImpl<UInt64, UInt32, DivideIntegralImpl<UInt64, UInt32>> : DivideIntegralByConstantImpl<UInt64, UInt32> {};
template <> struct BinaryOperationImpl<UInt64, UInt64, DivideIntegralImpl<UInt64, UInt64>> : DivideIntegralByConstantImpl<UInt64, UInt64> {};
template <> struct BinaryOperationImpl<UInt32, UInt8, DivideIntegralImpl<UInt32, UInt8>> : DivideIntegralByConstantImpl<UInt32, UInt8> {};
template <> struct BinaryOperationImpl<UInt32, UInt16, DivideIntegralImpl<UInt32, UInt16>> : DivideIntegralByConstantImpl<UInt32, UInt16> {};
template <> struct BinaryOperationImpl<UInt32, UInt32, DivideIntegralImpl<UInt32, UInt32>> : DivideIntegralByConstantImpl<UInt32, UInt32> {};
template <> struct BinaryOperationImpl<UInt32, UInt64, DivideIntegralImpl<UInt32, UInt64>> : DivideIntegralByConstantImpl<UInt32, UInt64> {};
template <> struct BinaryOperationImpl<Int64, Int8, DivideIntegralImpl<Int64, Int8>> : DivideIntegralByConstantImpl<Int64, Int8> {};
template <> struct BinaryOperationImpl<Int64, Int16, DivideIntegralImpl<Int64, Int16>> : DivideIntegralByConstantImpl<Int64, Int16> {};
template <> struct BinaryOperationImpl<Int64, Int32, DivideIntegralImpl<Int64, Int32>> : DivideIntegralByConstantImpl<Int64, Int32> {};
template <> struct BinaryOperationImpl<Int64, Int64, DivideIntegralImpl<Int64, Int64>> : DivideIntegralByConstantImpl<Int64, Int64> {};
template <> struct BinaryOperationImpl<Int32, Int8, DivideIntegralImpl<Int32, Int8>> : DivideIntegralByConstantImpl<Int32, Int8> {};
template <> struct BinaryOperationImpl<Int32, Int16, DivideIntegralImpl<Int32, Int16>> : DivideIntegralByConstantImpl<Int32, Int16> {};
template <> struct BinaryOperationImpl<Int32, Int32, DivideIntegralImpl<Int32, Int32>> : DivideIntegralByConstantImpl<Int32, Int32> {};
template <> struct BinaryOperationImpl<Int32, Int64, DivideIntegralImpl<Int32, Int64>> : DivideIntegralByConstantImpl<Int32, Int64> {};
struct NameIntDiv { static constexpr auto name = "intDiv"; };
using FunctionIntDiv = FunctionBinaryArithmetic<DivideIntegralImpl, NameIntDiv, false>;
void registerFunctionIntDiv(FunctionFactory & factory)
{
factory.registerFunction<FunctionIntDiv>();
}
}