/// specified call site. Note that this method takes linear time, so it
/// should be used sparingly.
void CallGraphNode::removeCallEdgeFor(CallSite CS) {
- // Scan for the call site. Note that we aren't guaranteed to find the call
- // site in this node, even in reasonable situations. Passes like instcombine
- // can adjust callsites (e.g. folding bitcasts into calls to make them direct)
- // which can introduce new call sites. Since instcombine is not callgraph
- // aware, it doesn't know to tell CallGraph about this change.
- for (CalledFunctionsVector::iterator I = CalledFunctions.begin();
- I != CalledFunctions.end(); ++I) {
- if (I->first != CS) continue;
-
- I->second->DropRef();
- *I = CalledFunctions.back();
- CalledFunctions.pop_back();
- return;
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+ if (I->first == CS) {
+ I->second->DropRef();
+ *I = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ return;
+ }
+ }
+}
+
+// FIXME: REMOVE THIS WHEN HACK IS REMOVED FROM CGSCCPASSMGR.
+void CallGraphNode::removeCallEdgeFor(Instruction *CS) {
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+ if (I->first.getInstruction() == CS) {
+ I->second->DropRef();
+ *I = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ return;
+ }
}
+
}
+
// removeAnyCallEdgeTo - This method removes any call edges from this node to
// the specified callee function. This takes more time to execute than
// removeCallEdgeTo, so it should not be used unless necessary.
CallGraphNode *NewCallee) {
for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
assert(I != CalledFunctions.end() && "Cannot find callsite to replace!");
- if (I->first == Old) {
- I->first = New;
-
- // If the callee is changing, not just the callsite, then update it as
- // well.
- if (NewCallee) {
- I->second->DropRef();
- I->second = NewCallee;
- I->second->AddRef();
- }
- return;
+ if (I->first != Old) continue;
+
+ I->first = New;
+
+ // If the callee is changing, not just the callsite, then update it as
+ // well.
+ if (NewCallee) {
+ I->second->DropRef();
+ I->second = NewCallee;
+ I->second->AddRef();
}
+ return;
}
}
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "cgscc-passmgr"
#include "llvm/CallGraphSCCPass.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/ADT/SCCIterator.h"
#include "llvm/PassManagers.h"
#include "llvm/Function.h"
+#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
}
private:
- bool RunPassOnSCC(Pass *P, std::vector<CallGraphNode*> &CurSCC);
+ bool RunPassOnSCC(Pass *P, std::vector<CallGraphNode*> &CurSCC,
+ CallGraph &CG, bool &CallGraphUpToDate);
+ void RefreshCallGraph(std::vector<CallGraphNode*> &CurSCC, CallGraph &CG);
};
} // end anonymous namespace.
char CGPassManager::ID = 0;
-bool CGPassManager::RunPassOnSCC(Pass *P, std::vector<CallGraphNode*> &CurSCC) {
+bool CGPassManager::RunPassOnSCC(Pass *P, std::vector<CallGraphNode*> &CurSCC,
+ CallGraph &CG, bool &CallGraphUpToDate) {
bool Changed = false;
if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass*>(P)) {
+ if (!CallGraphUpToDate) {
+ RefreshCallGraph(CurSCC, CG);
+ CallGraphUpToDate = true;
+ }
+
StartPassTimer(P);
Changed = CGSP->runOnSCC(CurSCC);
StopPassTimer(P);
}
StopPassTimer(P);
+ // The the function pass(es) modified the IR, they may have clobbered the
+ // callgraph.
+ if (Changed && CallGraphUpToDate) {
+ DEBUG(errs() << "CGSCCPASSMGR: Pass Dirtied SCC: "
+ << P->getPassName() << '\n');
+ CallGraphUpToDate = false;
+ }
return Changed;
}
+void CGPassManager::RefreshCallGraph(std::vector<CallGraphNode*> &CurSCC,
+ CallGraph &CG) {
+ DenseMap<Instruction*, CallGraphNode*> CallSites;
+
+ DEBUG(errs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()
+ << " nodes:\n";
+ for (unsigned i = 0, e = CurSCC.size(); i != e; ++i)
+ CurSCC[i]->dump();
+ );
+
+ bool MadeChange = false;
+ MadeChange = MadeChange;
+
+ // Scan all functions in the SCC.
+ for (unsigned sccidx = 0, e = CurSCC.size(); sccidx != e; ++sccidx) {
+ CallGraphNode *CGN = CurSCC[sccidx];
+ Function *F = CGN->getFunction();
+ if (F == 0 || F->isDeclaration()) continue;
+
+ // Walk the function body looking for call sites. Sync up the call sites in
+ // CGN with those actually in the function.
+
+ // Get the set of call sites currently in the function.
+ for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ++I){
+ assert(I->first.getInstruction() &&
+ "Call site record in function should not be abstract");
+ assert(!CallSites.count(I->first.getInstruction()) &&
+ "Call site occurs in node multiple times");
+ CallSites.insert(std::make_pair(I->first.getInstruction(),
+ I->second));
+ }
+
+ // Loop over all of the instructions in the function, getting the callsites.
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+ CallSite CS = CallSite::get(I);
+ if (!CS.getInstruction()) continue;
+
+ // If this call site already existed in the callgraph, just verify it
+ // matches up to expectations and remove it from CallSites.
+ DenseMap<Instruction*, CallGraphNode*>::iterator ExistingIt =
+ CallSites.find(CS.getInstruction());
+ if (ExistingIt != CallSites.end()) {
+ CallGraphNode *ExistingNode = ExistingIt->second;
+
+ // Remove from CallSites since we have now seen it.
+ CallSites.erase(ExistingIt);
+
+ // Verify that the callee is right.
+ if (ExistingNode->getFunction() == CS.getCalledFunction())
+ continue;
+
+ // If not, we either went from a direct call to indirect, indirect to
+ // direct, or direct to different direct.
+ CallGraphNode *CalleeNode;
+ if (Function *Callee = CS.getCalledFunction())
+ CalleeNode = CG.getOrInsertFunction(Callee);
+ else
+ CalleeNode = CG.getCallsExternalNode();
+
+ CGN->replaceCallSite(CS, CS, CalleeNode);
+ MadeChange = true;
+ continue;
+ }
+
+ // If the call site didn't exist in the CGN yet, add it. We assume that
+ // newly introduced call sites won't be indirect. This could be fixed
+ // in the future.
+ CallGraphNode *CalleeNode;
+ if (Function *Callee = CS.getCalledFunction())
+ CalleeNode = CG.getOrInsertFunction(Callee);
+ else
+ CalleeNode = CG.getCallsExternalNode();
+
+ CGN->addCalledFunction(CS, CalleeNode);
+ MadeChange = true;
+ }
+
+ // After scanning this function, if we still have entries in callsites, then
+ // they are dangling pointers. Crap. Well, until we change CallGraph to
+ // use CallbackVH, we'll just zap them here. When we have that, this should
+ // turn into an assertion.
+ if (CallSites.empty()) continue;
+
+ for (DenseMap<Instruction*, CallGraphNode*>::iterator I = CallSites.begin(),
+ E = CallSites.end(); I != E; ++I)
+ // FIXME: I had to add a special horrible form of removeCallEdgeFor to
+ // support this. Remove the Instruction* version of it when we can.
+ CGN->removeCallEdgeFor(I->first);
+ MadeChange = true;
+ CallSites.clear();
+ }
+
+ DEBUG(if (MadeChange) {
+ errs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";
+ for (unsigned i = 0, e = CurSCC.size(); i != e; ++i)
+ CurSCC[i]->dump();
+ } else {
+ errs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";
+ }
+ );
+}
/// 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.
++CGI;
+ // CallGraphUpToDate - Keep track of whether the callgraph is known to be
+ // up-to-date or not. The CGSSC pass manager runs two types of passes:
+ // CallGraphSCC Passes and other random function passes. Because other
+ // random function passes are not CallGraph aware, they may clobber the
+ // call graph by introducing new calls or deleting other ones. This flag
+ // is set to false when we run a function pass so that we know to clean up
+ // the callgraph when we need to run a CGSCCPass again.
+ bool CallGraphUpToDate = true;
+
// Run all passes on current SCC.
for (unsigned PassNo = 0, e = getNumContainedPasses();
PassNo != e; ++PassNo) {
initializeAnalysisImpl(P);
// Actually run this pass on the current SCC.
- Changed |= RunPassOnSCC(P, CurSCC);
+ Changed |= RunPassOnSCC(P, CurSCC, CG, CallGraphUpToDate);
if (Changed)
dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
recordAvailableAnalysis(P);
removeDeadPasses(P, "", ON_CG_MSG);
}
+
+ // If the callgraph was left out of date (because the last pass run was a
+ // functionpass), refresh it before we move on to the next SCC.
+ if (!CallGraphUpToDate)
+ RefreshCallGraph(CurSCC, CG);
}
Changed |= doFinalization(CG);
return Changed;