| //===- BottomUpClosure.cpp - Compute bottom-up interprocedural closure ----===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the BUDataStructures class, which represents the |
| // Bottom-Up Interprocedural closure of the data structure graph over the |
| // program. This is useful for applications like pool allocation, but **not** |
| // applications like alias analysis. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/DataStructure.h" |
| #include "llvm/Module.h" |
| #include "Support/Statistic.h" |
| #include "Support/Debug.h" |
| #include "DSCallSiteIterator.h" |
| using namespace llvm; |
| |
| namespace { |
| Statistic<> MaxSCC("budatastructure", "Maximum SCC Size in Call Graph"); |
| Statistic<> NumBUInlines("budatastructures", "Number of graphs inlined"); |
| Statistic<> NumCallEdges("budatastructures", "Number of 'actual' call edges"); |
| |
| RegisterAnalysis<BUDataStructures> |
| X("budatastructure", "Bottom-up Data Structure Analysis"); |
| } |
| |
| using namespace DS; |
| |
| // run - Calculate the bottom up data structure graphs for each function in the |
| // program. |
| // |
| bool BUDataStructures::run(Module &M) { |
| LocalDataStructures &LocalDSA = getAnalysis<LocalDataStructures>(); |
| GlobalsGraph = new DSGraph(LocalDSA.getGlobalsGraph()); |
| GlobalsGraph->setPrintAuxCalls(); |
| |
| Function *MainFunc = M.getMainFunction(); |
| if (MainFunc) |
| calculateReachableGraphs(MainFunc); |
| |
| // Calculate the graphs for any functions that are unreachable from main... |
| for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) |
| if (!I->isExternal() && !DSInfo.count(I)) { |
| #ifndef NDEBUG |
| if (MainFunc) |
| std::cerr << "*** Function unreachable from main: " |
| << I->getName() << "\n"; |
| #endif |
| calculateReachableGraphs(I); // Calculate all graphs... |
| } |
| |
| NumCallEdges += ActualCallees.size(); |
| |
| // At the end of the bottom-up pass, the globals graph becomes complete. |
| // FIXME: This is not the right way to do this, but it is sorta better than |
| // nothing! In particular, externally visible globals and unresolvable call |
| // nodes at the end of the BU phase should make things that they point to |
| // incomplete in the globals graph. |
| // |
| GlobalsGraph->removeTriviallyDeadNodes(); |
| GlobalsGraph->maskIncompleteMarkers(); |
| return false; |
| } |
| |
| void BUDataStructures::calculateReachableGraphs(Function *F) { |
| std::vector<Function*> Stack; |
| hash_map<Function*, unsigned> ValMap; |
| unsigned NextID = 1; |
| calculateGraphs(F, Stack, NextID, ValMap); |
| } |
| |
| DSGraph &BUDataStructures::getOrCreateGraph(Function *F) { |
| // Has the graph already been created? |
| DSGraph *&Graph = DSInfo[F]; |
| if (Graph) return *Graph; |
| |
| // Copy the local version into DSInfo... |
| Graph = new DSGraph(getAnalysis<LocalDataStructures>().getDSGraph(*F)); |
| |
| Graph->setGlobalsGraph(GlobalsGraph); |
| Graph->setPrintAuxCalls(); |
| |
| // Start with a copy of the original call sites... |
| Graph->getAuxFunctionCalls() = Graph->getFunctionCalls(); |
| return *Graph; |
| } |
| |
| unsigned BUDataStructures::calculateGraphs(Function *F, |
| std::vector<Function*> &Stack, |
| unsigned &NextID, |
| hash_map<Function*, unsigned> &ValMap) { |
| assert(!ValMap.count(F) && "Shouldn't revisit functions!"); |
| unsigned Min = NextID++, MyID = Min; |
| ValMap[F] = Min; |
| Stack.push_back(F); |
| |
| // FIXME! This test should be generalized to be any function that we have |
| // already processed, in the case when there isn't a main or there are |
| // unreachable functions! |
| if (F->isExternal()) { // sprintf, fprintf, sscanf, etc... |
| // No callees! |
| Stack.pop_back(); |
| ValMap[F] = ~0; |
| return Min; |
| } |
| |
| DSGraph &Graph = getOrCreateGraph(F); |
| |
| // The edges out of the current node are the call site targets... |
| for (DSCallSiteIterator I = DSCallSiteIterator::begin_aux(Graph), |
| E = DSCallSiteIterator::end_aux(Graph); I != E; ++I) { |
| Function *Callee = *I; |
| unsigned M; |
| // Have we visited the destination function yet? |
| hash_map<Function*, unsigned>::iterator It = ValMap.find(Callee); |
| if (It == ValMap.end()) // No, visit it now. |
| M = calculateGraphs(Callee, Stack, NextID, ValMap); |
| else // Yes, get it's number. |
| M = It->second; |
| if (M < Min) Min = M; |
| } |
| |
| assert(ValMap[F] == MyID && "SCC construction assumption wrong!"); |
| if (Min != MyID) |
| return Min; // This is part of a larger SCC! |
| |
| // If this is a new SCC, process it now. |
| if (Stack.back() == F) { // Special case the single "SCC" case here. |
| DEBUG(std::cerr << "Visiting single node SCC #: " << MyID << " fn: " |
| << F->getName() << "\n"); |
| Stack.pop_back(); |
| DSGraph &G = getDSGraph(*F); |
| DEBUG(std::cerr << " [BU] Calculating graph for: " << F->getName()<< "\n"); |
| calculateGraph(G); |
| DEBUG(std::cerr << " [BU] Done inlining: " << F->getName() << " [" |
| << G.getGraphSize() << "+" << G.getAuxFunctionCalls().size() |
| << "]\n"); |
| |
| if (MaxSCC < 1) MaxSCC = 1; |
| |
| // Should we revisit the graph? |
| if (DSCallSiteIterator::begin_aux(G) != DSCallSiteIterator::end_aux(G)) { |
| ValMap.erase(F); |
| return calculateGraphs(F, Stack, NextID, ValMap); |
| } else { |
| ValMap[F] = ~0U; |
| } |
| return MyID; |
| |
| } else { |
| // SCCFunctions - Keep track of the functions in the current SCC |
| // |
| hash_set<DSGraph*> SCCGraphs; |
| |
| Function *NF; |
| std::vector<Function*>::iterator FirstInSCC = Stack.end(); |
| DSGraph *SCCGraph = 0; |
| do { |
| NF = *--FirstInSCC; |
| ValMap[NF] = ~0U; |
| |
| // Figure out which graph is the largest one, in order to speed things up |
| // a bit in situations where functions in the SCC have widely different |
| // graph sizes. |
| DSGraph &NFGraph = getDSGraph(*NF); |
| SCCGraphs.insert(&NFGraph); |
| // FIXME: If we used a better way of cloning graphs (ie, just splice all |
| // of the nodes into the new graph), this would be completely unneeded! |
| if (!SCCGraph || SCCGraph->getGraphSize() < NFGraph.getGraphSize()) |
| SCCGraph = &NFGraph; |
| } while (NF != F); |
| |
| std::cerr << "Calculating graph for SCC #: " << MyID << " of size: " |
| << SCCGraphs.size() << "\n"; |
| |
| // Compute the Max SCC Size... |
| if (MaxSCC < SCCGraphs.size()) |
| MaxSCC = SCCGraphs.size(); |
| |
| // First thing first, collapse all of the DSGraphs into a single graph for |
| // the entire SCC. We computed the largest graph, so clone all of the other |
| // (smaller) graphs into it. Discard all of the old graphs. |
| // |
| for (hash_set<DSGraph*>::iterator I = SCCGraphs.begin(), |
| E = SCCGraphs.end(); I != E; ++I) { |
| DSGraph &G = **I; |
| if (&G != SCCGraph) { |
| { |
| DSGraph::NodeMapTy NodeMap; |
| SCCGraph->cloneInto(G, SCCGraph->getScalarMap(), |
| SCCGraph->getReturnNodes(), NodeMap); |
| } |
| // Update the DSInfo map and delete the old graph... |
| for (DSGraph::ReturnNodesTy::iterator I = G.getReturnNodes().begin(), |
| E = G.getReturnNodes().end(); I != E; ++I) |
| DSInfo[I->first] = SCCGraph; |
| delete &G; |
| } |
| } |
| |
| // Clean up the graph before we start inlining a bunch again... |
| SCCGraph->removeDeadNodes(DSGraph::RemoveUnreachableGlobals); |
| |
| // Now that we have one big happy family, resolve all of the call sites in |
| // the graph... |
| calculateGraph(*SCCGraph); |
| DEBUG(std::cerr << " [BU] Done inlining SCC [" << SCCGraph->getGraphSize() |
| << "+" << SCCGraph->getAuxFunctionCalls().size() << "]\n"); |
| |
| std::cerr << "DONE with SCC #: " << MyID << "\n"; |
| |
| // We never have to revisit "SCC" processed functions... |
| |
| // Drop the stuff we don't need from the end of the stack |
| Stack.erase(FirstInSCC, Stack.end()); |
| return MyID; |
| } |
| |
| return MyID; // == Min |
| } |
| |
| |
| // releaseMemory - If the pass pipeline is done with this pass, we can release |
| // our memory... here... |
| // |
| void BUDataStructures::releaseMemory() { |
| for (hash_map<Function*, DSGraph*>::iterator I = DSInfo.begin(), |
| E = DSInfo.end(); I != E; ++I) { |
| I->second->getReturnNodes().erase(I->first); |
| if (I->second->getReturnNodes().empty()) |
| delete I->second; |
| } |
| |
| // Empty map so next time memory is released, data structures are not |
| // re-deleted. |
| DSInfo.clear(); |
| delete GlobalsGraph; |
| GlobalsGraph = 0; |
| } |
| |
| void BUDataStructures::calculateGraph(DSGraph &Graph) { |
| // Move our call site list into TempFCs so that inline call sites go into the |
| // new call site list and doesn't invalidate our iterators! |
| std::vector<DSCallSite> TempFCs; |
| std::vector<DSCallSite> &AuxCallsList = Graph.getAuxFunctionCalls(); |
| TempFCs.swap(AuxCallsList); |
| |
| DSGraph::ReturnNodesTy &ReturnNodes = Graph.getReturnNodes(); |
| |
| // Loop over all of the resolvable call sites |
| unsigned LastCallSiteIdx = ~0U; |
| for (DSCallSiteIterator I = DSCallSiteIterator::begin(TempFCs), |
| E = DSCallSiteIterator::end(TempFCs); I != E; ++I) { |
| // If we skipped over any call sites, they must be unresolvable, copy them |
| // to the real call site list. |
| LastCallSiteIdx++; |
| for (; LastCallSiteIdx < I.getCallSiteIdx(); ++LastCallSiteIdx) |
| AuxCallsList.push_back(TempFCs[LastCallSiteIdx]); |
| LastCallSiteIdx = I.getCallSiteIdx(); |
| |
| // Resolve the current call... |
| Function *Callee = *I; |
| DSCallSite CS = I.getCallSite(); |
| |
| if (Callee->isExternal()) { |
| // Ignore this case, simple varargs functions we cannot stub out! |
| } else if (ReturnNodes.count(Callee)) { |
| // Self recursion... simply link up the formal arguments with the |
| // actual arguments... |
| DEBUG(std::cerr << " Self Inlining: " << Callee->getName() << "\n"); |
| |
| // Handle self recursion by resolving the arguments and return value |
| Graph.mergeInGraph(CS, *Callee, Graph, 0); |
| |
| } else { |
| ActualCallees.insert(std::make_pair(CS.getCallSite().getInstruction(), |
| Callee)); |
| |
| // Get the data structure graph for the called function. |
| // |
| DSGraph &GI = getDSGraph(*Callee); // Graph to inline |
| |
| DEBUG(std::cerr << " Inlining graph for " << Callee->getName() |
| << "[" << GI.getGraphSize() << "+" |
| << GI.getAuxFunctionCalls().size() << "] into '" |
| << Graph.getFunctionNames() << "' [" << Graph.getGraphSize() << "+" |
| << Graph.getAuxFunctionCalls().size() << "]\n"); |
| Graph.mergeInGraph(CS, *Callee, GI, |
| DSGraph::KeepModRefBits | |
| DSGraph::StripAllocaBit | DSGraph::DontCloneCallNodes); |
| ++NumBUInlines; |
| |
| #if 0 |
| Graph.writeGraphToFile(std::cerr, "bu_" + F.getName() + "_after_" + |
| Callee->getName()); |
| #endif |
| } |
| } |
| |
| // Make sure to catch any leftover unresolvable calls... |
| for (++LastCallSiteIdx; LastCallSiteIdx < TempFCs.size(); ++LastCallSiteIdx) |
| AuxCallsList.push_back(TempFCs[LastCallSiteIdx]); |
| |
| TempFCs.clear(); |
| |
| // Recompute the Incomplete markers |
| assert(Graph.getInlinedGlobals().empty()); |
| Graph.maskIncompleteMarkers(); |
| Graph.markIncompleteNodes(DSGraph::MarkFormalArgs); |
| |
| // Delete dead nodes. Treat globals that are unreachable but that can |
| // reach live nodes as live. |
| Graph.removeDeadNodes(DSGraph::KeepUnreachableGlobals); |
| |
| // When this graph is finalized, clone the globals in the graph into the |
| // globals graph to make sure it has everything, from all graphs. |
| DSScalarMap &MainSM = Graph.getScalarMap(); |
| ReachabilityCloner RC(*GlobalsGraph, Graph, DSGraph::StripAllocaBit); |
| |
| // Clone everything reachable from globals in the "main" graph into the |
| // globals graph. |
| for (DSScalarMap::global_iterator I = MainSM.global_begin(), |
| E = MainSM.global_end(); I != E; ++I) |
| RC.getClonedNH(MainSM[*I]); |
| |
| //Graph.writeGraphToFile(std::cerr, "bu_" + F.getName()); |
| } |
