ClickHouse/src/Functions/bitRotateRight.cpp
2020-09-07 21:00:37 +03:00

55 lines
1.7 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionBinaryArithmetic.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NOT_IMPLEMENTED;
extern const int LOGICAL_ERROR;
}
namespace
{
template <typename A, typename B>
struct BitRotateRightImpl
{
using ResultType = typename NumberTraits::ResultOfBit<A, B>::Type;
static const constexpr bool allow_fixed_string = false;
template <typename Result = ResultType>
static inline NO_SANITIZE_UNDEFINED Result apply(A a [[maybe_unused]], B b [[maybe_unused]])
{
if constexpr (is_big_int_v<A> || is_big_int_v<B>)
throw Exception("Bit rotate is not implemented for big integers", ErrorCodes::NOT_IMPLEMENTED);
else
return (static_cast<Result>(a) >> static_cast<Result>(b))
| (static_cast<Result>(a) << ((sizeof(Result) * 8) - static_cast<Result>(b)));
}
#if USE_EMBEDDED_COMPILER
static constexpr bool compilable = true;
static inline llvm::Value * compile(llvm::IRBuilder<> & b, llvm::Value * left, llvm::Value * right, bool)
{
if (!left->getType()->isIntegerTy())
throw Exception("BitRotateRightImpl expected an integral type", ErrorCodes::LOGICAL_ERROR);
auto * size = llvm::ConstantInt::get(left->getType(), left->getType()->getPrimitiveSizeInBits());
return b.CreateOr(b.CreateLShr(left, right), b.CreateShl(left, b.CreateSub(size, right)));
}
#endif
};
struct NameBitRotateRight { static constexpr auto name = "bitRotateRight"; };
using FunctionBitRotateRight = FunctionBinaryArithmetic<BitRotateRightImpl, NameBitRotateRight>;
}
void registerFunctionBitRotateRight(FunctionFactory & factory)
{
factory.registerFunction<FunctionBitRotateRight>();
}
}