1#include <Functions/FunctionFactory.h>
2#include <Functions/FunctionBinaryArithmetic.h>
3#include <Core/AccurateComparison.h>
4
5namespace DB
6{
7
8template <typename A, typename B>
9struct GreatestBaseImpl
10{
11 using ResultType = NumberTraits::ResultOfGreatest<A, B>;
12
13 template <typename Result = ResultType>
14 static inline Result apply(A a, B b)
15 {
16 return static_cast<Result>(a) > static_cast<Result>(b) ? static_cast<Result>(a) : static_cast<Result>(b);
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 * left, llvm::Value * right, bool is_signed)
23 {
24 if (!left->getType()->isIntegerTy())
25 /// XXX maxnum is basically fmax(), it may or may not match whatever apply() does
26 /// XXX CreateMaxNum is broken on LLVM 5.0 and 6.0 (generates minnum instead; fixed in 7)
27 return b.CreateBinaryIntrinsic(llvm::Intrinsic::maxnum, left, right);
28 return b.CreateSelect(is_signed ? b.CreateICmpSGT(left, right) : b.CreateICmpUGT(left, right), left, right);
29 }
30#endif
31};
32
33template <typename A, typename B>
34struct GreatestSpecialImpl
35{
36 using ResultType = std::make_unsigned_t<A>;
37
38 template <typename Result = ResultType>
39 static inline Result apply(A a, B b)
40 {
41 static_assert(std::is_same_v<Result, ResultType>, "ResultType != Result");
42 return accurate::greaterOp(a, b) ? static_cast<Result>(a) : static_cast<Result>(b);
43 }
44
45#if USE_EMBEDDED_COMPILER
46 static constexpr bool compilable = false; /// ???
47#endif
48};
49
50template <typename A, typename B>
51using GreatestImpl = std::conditional_t<!NumberTraits::LeastGreatestSpecialCase<A, B>, GreatestBaseImpl<A, B>, GreatestSpecialImpl<A, B>>;
52
53struct NameGreatest { static constexpr auto name = "greatest"; };
54using FunctionGreatest = FunctionBinaryArithmetic<GreatestImpl, NameGreatest>;
55
56void registerFunctionGreatest(FunctionFactory & factory)
57{
58 factory.registerFunction<FunctionGreatest>();
59}
60
61}
62