1 | #include <Functions/FunctionFactory.h> |
2 | #include <Functions/FunctionUnaryArithmetic.h> |
3 | #include <Common/FieldVisitors.h> |
4 | #include <Common/intExp.h> |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | template <typename A> |
10 | struct IntExp2Impl |
11 | { |
12 | using ResultType = UInt64; |
13 | |
14 | static inline ResultType apply(A a) |
15 | { |
16 | return intExp2(a); |
17 | } |
18 | |
19 | #if USE_EMBEDDED_COMPILER |
20 | static constexpr bool compilable = true; |
21 | |
22 | static inline llvm::Value * compile(llvm::IRBuilder<> & b, llvm::Value * arg, bool) |
23 | { |
24 | if (!arg->getType()->isIntegerTy()) |
25 | throw Exception("IntExp2Impl expected an integral type" , ErrorCodes::LOGICAL_ERROR); |
26 | return b.CreateShl(llvm::ConstantInt::get(arg->getType(), 1), arg); |
27 | } |
28 | #endif |
29 | }; |
30 | |
31 | /// Assumed to be injective for the purpose of query optimization, but in fact it is not injective because of possible overflow. |
32 | struct NameIntExp2 { static constexpr auto name = "intExp2" ; }; |
33 | using FunctionIntExp2 = FunctionUnaryArithmetic<IntExp2Impl, NameIntExp2, true>; |
34 | |
35 | template <> struct FunctionUnaryArithmeticMonotonicity<NameIntExp2> |
36 | { |
37 | static bool has() { return true; } |
38 | static IFunction::Monotonicity get(const Field & left, const Field & right) |
39 | { |
40 | Float64 left_float = left.isNull() ? -std::numeric_limits<Float64>::infinity() : applyVisitor(FieldVisitorConvertToNumber<Float64>(), left); |
41 | Float64 right_float = right.isNull() ? std::numeric_limits<Float64>::infinity() : applyVisitor(FieldVisitorConvertToNumber<Float64>(), right); |
42 | |
43 | if (left_float < 0 || right_float > 63) |
44 | return {}; |
45 | |
46 | return { true }; |
47 | } |
48 | }; |
49 | |
50 | void registerFunctionIntExp2(FunctionFactory & factory) |
51 | { |
52 | factory.registerFunction<FunctionIntExp2>(); |
53 | } |
54 | |
55 | } |
56 | |