//===- Inliner.h - Inliner pass and infrastructure --------------*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_IPO_INLINER_H
#define LLVM_TRANSFORMS_IPO_INLINER_H
#include "llvm/Analysis/CGSCCPassManager.h"
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/Analysis/InlineAdvisor.h"
#include "llvm/Analysis/InlineCost.h"
#include "llvm/Analysis/LazyCallGraph.h"
#include "llvm/Analysis/Utils/ImportedFunctionsInliningStatistics.h"
#include "llvm/IR/PassManager.h"
namespace llvm {
class AssumptionCacheTracker;
class CallGraph;
class ProfileSummaryInfo;
/// This class contains all of the helper code which is used to perform the
/// inlining operations that do not depend on the policy. It contains the core
/// bottom-up inlining infrastructure that specific inliner passes use.
struct LegacyInlinerBase : public CallGraphSCCPass {
explicit LegacyInlinerBase(char &ID);
explicit LegacyInlinerBase(char &ID, bool InsertLifetime);
/// For this class, we declare that we require and preserve the call graph.
/// If the derived class implements this method, it should always explicitly
/// call the implementation here.
void getAnalysisUsage(AnalysisUsage &Info) const override;
using llvm::Pass::doInitialization;
bool doInitialization(CallGraph &CG) override;
/// Main run interface method, this implements the interface required by the
/// Pass class.
bool runOnSCC(CallGraphSCC &SCC) override;
using llvm::Pass::doFinalization;
/// Remove now-dead linkonce functions at the end of processing to avoid
/// breaking the SCC traversal.
bool doFinalization(CallGraph &CG) override;
/// This method must be implemented by the subclass to determine the cost of
/// inlining the specified call site. If the cost returned is greater than
/// the current inline threshold, the call site is not inlined.
virtual InlineCost getInlineCost(CallBase &CB) = 0;
/// Remove dead functions.
///
/// This also includes a hack in the form of the 'AlwaysInlineOnly' flag
/// which restricts it to deleting functions with an 'AlwaysInline'
/// attribute. This is useful for the InlineAlways pass that only wants to
/// deal with that subset of the functions.
bool removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly = false);
/// This function performs the main work of the pass. The default of
/// Inlinter::runOnSCC() calls skipSCC() before calling this method, but
/// derived classes which cannot be skipped can override that method and call
/// this function unconditionally.
bool inlineCalls(CallGraphSCC &SCC);
private:
// Insert @llvm.lifetime intrinsics.
bool InsertLifetime = true;
protected:
AssumptionCacheTracker *ACT;
ProfileSummaryInfo *PSI;
std::function<const TargetLibraryInfo &(Function &)> GetTLI;
ImportedFunctionsInliningStatistics ImportedFunctionsStats;
};
/// The inliner pass for the new pass manager.
///
/// This pass wires together the inlining utilities and the inline cost
/// analysis into a CGSCC pass. It considers every call in every function in
/// the SCC and tries to inline if profitable. It can be tuned with a number of
/// parameters to control what cost model is used and what tradeoffs are made
/// when making the decision.
///
/// It should be noted that the legacy inliners do considerably more than this
/// inliner pass does. They provide logic for manually merging allocas, and
/// doing considerable DCE including the DCE of dead functions. This pass makes
/// every attempt to be simpler. DCE of functions requires complex reasoning
/// about comdat groups, etc. Instead, it is expected that other more focused
/// passes be composed to achieve the same end result.
class InlinerPass : public PassInfoMixin<InlinerPass> {
public:
InlinerPass(bool OnlyMandatory = false,
ThinOrFullLTOPhase LTOPhase = ThinOrFullLTOPhase::None)
: OnlyMandatory(OnlyMandatory), LTOPhase(LTOPhase) {}
InlinerPass(InlinerPass &&Arg) = default;
PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM,
LazyCallGraph &CG, CGSCCUpdateResult &UR);
void printPipeline(raw_ostream &OS,
function_ref<StringRef(StringRef)> MapClassName2PassName);
private:
InlineAdvisor &getAdvisor(const ModuleAnalysisManagerCGSCCProxy::Result &MAM,
FunctionAnalysisManager &FAM, Module &M);
std::unique_ptr<InlineAdvisor> OwnedAdvisor;
const bool OnlyMandatory;
const ThinOrFullLTOPhase LTOPhase;
};
/// Module pass, wrapping the inliner pass. This works in conjunction with the
/// InlineAdvisorAnalysis to facilitate inlining decisions taking into account
/// module-wide state, that need to keep track of inter-inliner pass runs, for
/// a given module. An InlineAdvisor is configured and kept alive for the
/// duration of the ModuleInlinerWrapperPass::run.
class ModuleInlinerWrapperPass
: public PassInfoMixin<ModuleInlinerWrapperPass> {
public:
ModuleInlinerWrapperPass(
InlineParams Params = getInlineParams(), bool MandatoryFirst = true,
InlineContext IC = {},
InliningAdvisorMode Mode = InliningAdvisorMode::Default,
unsigned MaxDevirtIterations = 0);
ModuleInlinerWrapperPass(ModuleInlinerWrapperPass &&Arg) = default;
PreservedAnalyses run(Module &, ModuleAnalysisManager &);
/// Allow adding more CGSCC passes, besides inlining. This should be called
/// before run is called, as part of pass pipeline building.
CGSCCPassManager &getPM() { return PM; }
/// Add a module pass that runs before the CGSCC passes.
template <class T> void addModulePass(T Pass) {
MPM.addPass(std::move(Pass));
}
/// Add a module pass that runs after the CGSCC passes.
template <class T> void addLateModulePass(T Pass) {
AfterCGMPM.addPass(std::move(Pass));
}
void printPipeline(raw_ostream &OS,
function_ref<StringRef(StringRef)> MapClassName2PassName);
private:
const InlineParams Params;
const InlineContext IC;
const InliningAdvisorMode Mode;
const unsigned MaxDevirtIterations;
// TODO: Clean this up so we only have one ModulePassManager.
CGSCCPassManager PM;
ModulePassManager MPM;
ModulePassManager AfterCGMPM;
};
} // end namespace llvm
#endif // LLVM_TRANSFORMS_IPO_INLINER_H