llvm-for-llvmta/include/llvm/Analysis/Utils/ImportedFunctionsInliningSt...

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4.4 KiB
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//===-- ImportedFunctionsInliningStatistics.h -------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Generating inliner statistics for imported functions, mostly useful for
// ThinLTO.
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_UTILS_IMPORTEDFUNCTIONSINLININGSTATISTICS_H
#define LLVM_TRANSFORMS_UTILS_IMPORTEDFUNCTIONSINLININGSTATISTICS_H
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include <string>
#include <vector>
namespace llvm {
class Module;
class Function;
/// Calculate and dump ThinLTO specific inliner stats.
/// The main statistics are:
/// (1) Number of inlined imported functions,
/// (2) Number of imported functions inlined into importing module (indirect),
/// (3) Number of non imported functions inlined into importing module
/// (indirect).
/// The difference between first and the second is that first stat counts
/// all performed inlines on imported functions, but the second one only the
/// functions that have been eventually inlined to a function in the importing
/// module (by a chain of inlines). Because llvm uses bottom-up inliner, it is
/// possible to e.g. import function `A`, `B` and then inline `B` to `A`,
/// and after this `A` might be too big to be inlined into some other function
/// that calls it. It calculates this statistic by building graph, where
/// the nodes are functions, and edges are performed inlines and then by marking
/// the edges starting from not imported function.
///
/// If `Verbose` is set to true, then it also dumps statistics
/// per each inlined function, sorted by the greatest inlines count like
/// - number of performed inlines
/// - number of performed inlines to importing module
class ImportedFunctionsInliningStatistics {
private:
/// InlineGraphNode represents node in graph of inlined functions.
struct InlineGraphNode {
// Default-constructible and movable.
InlineGraphNode() = default;
InlineGraphNode(InlineGraphNode &&) = default;
InlineGraphNode &operator=(InlineGraphNode &&) = default;
llvm::SmallVector<InlineGraphNode *, 8> InlinedCallees;
/// Incremented every direct inline.
int32_t NumberOfInlines = 0;
/// Number of inlines into non imported function (possibly indirect via
/// intermediate inlines). Computed based on graph search.
int32_t NumberOfRealInlines = 0;
bool Imported = false;
bool Visited = false;
};
public:
ImportedFunctionsInliningStatistics() = default;
ImportedFunctionsInliningStatistics(
const ImportedFunctionsInliningStatistics &) = delete;
/// Set information like AllFunctions, ImportedFunctions, ModuleName.
void setModuleInfo(const Module &M);
/// Record inline of @param Callee to @param Caller for statistis.
void recordInline(const Function &Caller, const Function &Callee);
/// Dump stats computed with InlinerStatistics class.
/// If @param Verbose is true then separate statistics for every inlined
/// function will be printed.
void dump(bool Verbose);
private:
/// Creates new Node in NodeMap and sets attributes, or returns existed one.
InlineGraphNode &createInlineGraphNode(const Function &);
void calculateRealInlines();
void dfs(InlineGraphNode &GraphNode);
using NodesMapTy =
llvm::StringMap<std::unique_ptr<InlineGraphNode>>;
using SortedNodesTy =
std::vector<const NodesMapTy::MapEntryTy*>;
/// Returns vector of elements sorted by
/// (-NumberOfInlines, -NumberOfRealInlines, FunctionName).
SortedNodesTy getSortedNodes();
private:
/// This map manage life of all InlineGraphNodes. Unique pointer to
/// InlineGraphNode used since the node pointers are also saved in the
/// InlinedCallees vector. If it would store InlineGraphNode instead then the
/// address of the node would not be invariant.
NodesMapTy NodesMap;
/// Non external functions that have some other function inlined inside.
std::vector<StringRef> NonImportedCallers;
int AllFunctions = 0;
int ImportedFunctions = 0;
StringRef ModuleName;
};
enum class InlinerFunctionImportStatsOpts {
No = 0,
Basic = 1,
Verbose = 2,
};
} // llvm
#endif // LLVM_TRANSFORMS_UTILS_IMPORTEDFUNCTIONSINLININGSTATISTICS_H