llvm-6502/lib/Analysis/IPA/CallGraphSCCPass.cpp

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//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the CallGraphSCCPass class, which is used for passes
// which are implemented as bottom-up traversals on the call graph. Because
// there may be cycles in the call graph, passes of this type operate on the
// call-graph in SCC order: that is, they process function bottom-up, except for
// recursive functions, which they process all at once.
//
//===----------------------------------------------------------------------===//
#include "llvm/CallGraphSCCPass.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/ADT/SCCIterator.h"
#include "llvm/PassManagers.h"
#include "llvm/Function.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// CGPassManager
//
/// CGPassManager manages FPPassManagers and CalLGraphSCCPasses.
class CGPassManager : public ModulePass, public PMDataManager {
public:
static char ID;
explicit CGPassManager(int Depth)
: ModulePass((intptr_t)&ID), PMDataManager(Depth) { }
/// run - Execute all of the passes scheduled for execution. Keep track of
/// whether any of the passes modifies the module, and if so, return true.
bool runOnModule(Module &M);
bool doInitialization(CallGraph &CG);
bool doFinalization(CallGraph &CG);
/// Pass Manager itself does not invalidate any analysis info.
void getAnalysisUsage(AnalysisUsage &Info) const {
// CGPassManager walks SCC and it needs CallGraph.
Info.addRequired<CallGraph>();
Info.setPreservesAll();
}
virtual const char *getPassName() const {
return "CallGraph Pass Manager";
}
// Print passes managed by this manager
void dumpPassStructure(unsigned Offset) {
llvm::cerr << std::string(Offset*2, ' ') << "Call Graph SCC Pass Manager\n";
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
P->dumpPassStructure(Offset + 1);
dumpLastUses(P, Offset+1);
}
}
Pass *getContainedPass(unsigned N) {
assert ( N < PassVector.size() && "Pass number out of range!");
Pass *FP = static_cast<Pass *>(PassVector[N]);
return FP;
}
virtual PassManagerType getPassManagerType() const {
return PMT_CallGraphPassManager;
}
};
char CGPassManager::ID = 0;
/// run - Execute all of the passes scheduled for execution. Keep track of
/// whether any of the passes modifies the module, and if so, return true.
bool CGPassManager::runOnModule(Module &M) {
CallGraph &CG = getAnalysis<CallGraph>();
bool Changed = doInitialization(CG);
// Walk SCC
for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG);
I != E; ++I) {
// Run all passes on current SCC
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
AnalysisUsage AnUsage;
P->getAnalysisUsage(AnUsage);
dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, "");
dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
initializeAnalysisImpl(P);
StartPassTimer(P);
if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
Changed |= CGSP->runOnSCC(*I); // TODO : What if CG is changed ?
else {
FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
assert (FPP && "Invalid CGPassManager member");
// Run pass P on all functions current SCC
std::vector<CallGraphNode*> &SCC = *I;
for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
Function *F = SCC[i]->getFunction();
if (F) {
dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getNameStart());
Changed |= FPP->runOnFunction(*F);
}
}
}
StopPassTimer(P);
if (Changed)
dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
verifyPreservedAnalysis(P);
removeNotPreservedAnalysis(P);
recordAvailableAnalysis(P);
removeDeadPasses(P, "", ON_CG_MSG);
}
}
Changed |= doFinalization(CG);
return Changed;
}
/// Initialize CG
bool CGPassManager::doInitialization(CallGraph &CG) {
bool Changed = false;
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
Changed |= CGSP->doInitialization(CG);
}
return Changed;
}
/// Finalize CG
bool CGPassManager::doFinalization(CallGraph &CG) {
bool Changed = false;
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
Changed |= CGSP->doFinalization(CG);
}
return Changed;
}
/// Assign pass manager to manage this pass.
void CallGraphSCCPass::assignPassManager(PMStack &PMS,
PassManagerType PreferredType) {
// Find CGPassManager
while (!PMS.empty() &&
PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
PMS.pop();
assert (!PMS.empty() && "Unable to handle Call Graph Pass");
CGPassManager *CGP = dynamic_cast<CGPassManager *>(PMS.top());
// Create new Call Graph SCC Pass Manager if it does not exist.
if (!CGP) {
assert (!PMS.empty() && "Unable to create Call Graph Pass Manager");
PMDataManager *PMD = PMS.top();
// [1] Create new Call Graph Pass Manager
CGP = new CGPassManager(PMD->getDepth() + 1);
// [2] Set up new manager's top level manager
PMTopLevelManager *TPM = PMD->getTopLevelManager();
TPM->addIndirectPassManager(CGP);
// [3] Assign manager to manage this new manager. This may create
// and push new managers into PMS
Pass *P = dynamic_cast<Pass *>(CGP);
TPM->schedulePass(P);
// [4] Push new manager into PMS
PMS.push(CGP);
}
CGP->add(this);
}
/// getAnalysisUsage - 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 CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<CallGraph>();
AU.addPreserved<CallGraph>();
}