ClickHouse/src/Interpreters/ExpressionJIT.h
2020-04-03 18:14:31 +03:00

80 lines
2.6 KiB
C++

#pragma once
#include "config_core.h"
#if USE_EMBEDDED_COMPILER
#include <Functions/IFunctionImpl.h>
#include <Interpreters/Context.h>
#include <Interpreters/ExpressionActions.h>
#include <Common/LRUCache.h>
#include <set>
namespace DB
{
using CompilableExpression = std::function<llvm::Value * (llvm::IRBuilderBase &, const ValuePlaceholders &)>;
struct LLVMModuleState;
class LLVMFunction : public IFunctionBaseImpl
{
std::string name;
Names arg_names;
DataTypes arg_types;
std::vector<FunctionBasePtr> originals;
std::unordered_map<StringRef, CompilableExpression> subexpressions;
std::unique_ptr<LLVMModuleState> module_state;
public:
LLVMFunction(const ExpressionActions::Actions & actions, const Block & sample_block);
bool isCompilable() const override { return true; }
llvm::Value * compile(llvm::IRBuilderBase & builder, ValuePlaceholders values) const override;
String getName() const override { return name; }
const Names & getArgumentNames() const { return arg_names; }
const DataTypes & getArgumentTypes() const override { return arg_types; }
const DataTypePtr & getReturnType() const override { return originals.back()->getReturnType(); }
ExecutableFunctionImplPtr prepare(const Block &, const ColumnNumbers &, size_t) const override;
bool isDeterministic() const override;
bool isDeterministicInScopeOfQuery() const override;
bool isSuitableForConstantFolding() const override;
bool isInjective(const Block & sample_block) override;
bool hasInformationAboutMonotonicity() const override;
Monotonicity getMonotonicityForRange(const IDataType & type, const Field & left, const Field & right) const override;
const LLVMModuleState * getLLVMModuleState() const { return module_state.get(); }
};
/** This child of LRUCache breaks one of it's invariants: total weight may be changed after insertion.
* We have to do so, because we don't known real memory consumption of generated LLVM code for every function.
*/
class CompiledExpressionCache : public LRUCache<UInt128, IFunctionBase, UInt128Hash>
{
public:
using Base = LRUCache<UInt128, IFunctionBase, UInt128Hash>;
using Base::Base;
};
/// For each APPLY_FUNCTION action, try to compile the function to native code; if the only uses of a compilable
/// function's result are as arguments to other compilable functions, inline it and leave the now-redundant action as-is.
void compileFunctions(ExpressionActions::Actions & actions, const Names & output_columns, const Block & sample_block, std::shared_ptr<CompiledExpressionCache> compilation_cache, size_t min_count_to_compile_expression);
}
#endif