ClickHouse/dbms/src/Functions/bitRotateLeft.cpp
2018-12-27 02:55:09 +03:00

42 lines
1.4 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionBinaryArithmetic.h>
namespace DB
{
template <typename A, typename B>
struct BitRotateLeftImpl
{
using ResultType = typename NumberTraits::ResultOfBit<A, B>::Type;
template <typename Result = ResultType>
static inline NO_SANITIZE_UNDEFINED Result apply(A a, B b)
{
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("BitRotateLeftImpl expected an integral type", ErrorCodes::LOGICAL_ERROR);
auto * size = llvm::ConstantInt::get(left->getType(), left->getType()->getPrimitiveSizeInBits());
/// XXX how is this supposed to behave in signed mode?
return b.CreateOr(b.CreateShl(left, right), b.CreateLShr(left, b.CreateSub(size, right)));
}
#endif
};
struct NameBitRotateLeft { static constexpr auto name = "bitRotateLeft"; };
using FunctionBitRotateLeft = FunctionBinaryArithmetic<BitRotateLeftImpl, NameBitRotateLeft>;
void registerFunctionBitRotateLeft(FunctionFactory & factory)
{
factory.registerFunction<FunctionBitRotateLeft>();
}
}