//===- TopDownClosure.cpp - Compute the top-down interprocedure 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 TDDataStructures class, which represents the
// Top-down Interprocedural closure of the data structure graph over the
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/DataStructure.h"
-#include "llvm/Analysis/DSGraph.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
+#include "llvm/Analysis/DSGraph.h"
+#include "Support/Debug.h"
#include "Support/Statistic.h"
-#include <set>
+using namespace llvm;
-static RegisterAnalysis<TDDataStructures>
-Y("tddatastructure", "Top-down Data Structure Analysis Closure");
+namespace {
+ RegisterAnalysis<TDDataStructures> // Register the pass
+ Y("tddatastructure", "Top-down Data Structure Analysis");
-// releaseMemory - If the pass pipeline is done with this pass, we can release
-// our memory... here...
-//
-void TDDataStructures::releaseMemory() {
- BUMaps.clear();
- for (std::map<const Function*, DSGraph*>::iterator I = DSInfo.begin(),
- E = DSInfo.end(); I != E; ++I)
- delete I->second;
+ Statistic<> NumTDInlines("tddatastructures", "Number of graphs inlined");
+}
- // Empty map so next time memory is released, data structures are not
- // re-deleted.
- DSInfo.clear();
+void TDDataStructures::markReachableFunctionsExternallyAccessible(DSNode *N,
+ hash_set<DSNode*> &Visited) {
+ if (!N || Visited.count(N)) return;
+ Visited.insert(N);
+
+ for (unsigned i = 0, e = N->getNumLinks(); i != e; ++i) {
+ DSNodeHandle &NH = N->getLink(i*N->getPointerSize());
+ if (DSNode *NN = NH.getNode()) {
+ const std::vector<GlobalValue*> &Globals = NN->getGlobals();
+ for (unsigned G = 0, e = Globals.size(); G != e; ++G)
+ if (Function *F = dyn_cast<Function>(Globals[G]))
+ ArgsRemainIncomplete.insert(F);
+
+ markReachableFunctionsExternallyAccessible(NN, Visited);
+ }
+ }
}
+
// run - Calculate the top down data structure graphs for each function in the
// program.
//
bool TDDataStructures::run(Module &M) {
BUDataStructures &BU = getAnalysis<BUDataStructures>();
+ GlobalsGraph = new DSGraph(BU.getGlobalsGraph());
+ GlobalsGraph->setPrintAuxCalls();
- // Calculate the CallSitesForFunction mapping from the BU info...
+ // Figure out which functions must not mark their arguments complete because
+ // they are accessible outside this compilation unit. Currently, these
+ // arguments are functions which are reachable by global variables in the
+ // globals graph.
+ const DSGraph::ScalarMapTy &GGSM = GlobalsGraph->getScalarMap();
+ hash_set<DSNode*> Visited;
+ for (DSGraph::ScalarMapTy::const_iterator I = GGSM.begin(), E = GGSM.end();
+ I != E; ++I)
+ if (isa<GlobalValue>(I->first))
+ markReachableFunctionsExternallyAccessible(I->second.getNode(), Visited);
+
+ // Loop over unresolved call nodes. Any functions passed into (but not
+ // returned!) from unresolvable call nodes may be invoked outside of the
+ // current module.
+ const std::vector<DSCallSite> &Calls = GlobalsGraph->getAuxFunctionCalls();
+ for (unsigned i = 0, e = Calls.size(); i != e; ++i) {
+ const DSCallSite &CS = Calls[i];
+ for (unsigned arg = 0, e = CS.getNumPtrArgs(); arg != e; ++arg)
+ markReachableFunctionsExternallyAccessible(CS.getPtrArg(arg).getNode(),
+ Visited);
+ }
+ Visited.clear();
+
+ // Functions without internal linkage also have unknown incoming arguments!
+ for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+ if (!I->isExternal() && !I->hasInternalLinkage())
+ ArgsRemainIncomplete.insert(I);
+
+ // We want to traverse the call graph in reverse post-order. To do this, we
+ // calculate a post-order traversal, then reverse it.
+ hash_set<DSGraph*> VisitedGraph;
+ std::vector<DSGraph*> PostOrder;
+ const BUDataStructures::ActualCalleesTy &ActualCallees =
+ getAnalysis<BUDataStructures>().getActualCallees();
+
+ // Calculate top-down from main...
+ if (Function *F = M.getMainFunction())
+ ComputePostOrder(*F, VisitedGraph, PostOrder, ActualCallees);
+
+ // Next calculate the graphs for each unreachable function...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
- if (!I->isExternal())
- if (const std::vector<DSCallSite> *CS = BU.getCallSites(*I))
- for (unsigned i = 0, e = CS->size(); i != e; ++i)
- if (Function *F = (*CS)[i].getResolvingCaller())
- CallSitesForFunction[F].push_back(&(*CS)[i]);
-
- // Next calculate the graphs for each function...
- for (Module::reverse_iterator I = M.rbegin(), E = M.rend(); I != E; ++I)
- if (!I->isExternal())
- calculateGraph(*I);
-
- // Destroy the temporary mapping...
- CallSitesForFunction.clear();
+ ComputePostOrder(*I, VisitedGraph, PostOrder, ActualCallees);
+
+ VisitedGraph.clear(); // Release memory!
+
+ // Visit each of the graphs in reverse post-order now!
+ while (!PostOrder.empty()) {
+ inlineGraphIntoCallees(*PostOrder.back());
+ PostOrder.pop_back();
+ }
+
+ ArgsRemainIncomplete.clear();
return false;
}
-/// ResolveCallSite - This method is used to link the actual arguments together
-/// with the formal arguments for a function call in the top-down closure. This
-/// method assumes that the call site arguments have been mapped into nodes
-/// local to the specified graph.
-///
-void TDDataStructures::ResolveCallSite(DSGraph &Graph,
- const DSCallSite &CallSite) {
- // Resolve all of the function formal arguments...
- Function &F = Graph.getFunction();
- Function::aiterator AI = F.abegin();
-
- for (unsigned i = 0, e = CallSite.getNumPtrArgs(); i != e; ++i, ++AI) {
- // Advance the argument iterator to the first pointer argument...
- while (!DS::isPointerType(AI->getType())) ++AI;
-
- // TD ...Merge the formal arg scalar with the actual arg node
- DSNodeHandle &NodeForFormal = Graph.getNodeForValue(AI);
- assert(NodeForFormal.getNode() && "Pointer argument has no dest node!");
- NodeForFormal.mergeWith(CallSite.getPtrArg(i));
+
+DSGraph &TDDataStructures::getOrCreateDSGraph(Function &F) {
+ DSGraph *&G = DSInfo[&F];
+ if (G == 0) { // Not created yet? Clone BU graph...
+ G = new DSGraph(getAnalysis<BUDataStructures>().getDSGraph(F));
+ G->getAuxFunctionCalls().clear();
+ G->setPrintAuxCalls();
+ G->setGlobalsGraph(GlobalsGraph);
}
+ return *G;
+}
+
+
+void TDDataStructures::ComputePostOrder(Function &F,hash_set<DSGraph*> &Visited,
+ std::vector<DSGraph*> &PostOrder,
+ const BUDataStructures::ActualCalleesTy &ActualCallees) {
+ if (F.isExternal()) return;
+ DSGraph &G = getOrCreateDSGraph(F);
+ if (Visited.count(&G)) return;
+ Visited.insert(&G);
- // Merge returned node in the caller with the "return" node in callee
- if (CallSite.getRetVal().getNode() && Graph.getRetNode().getNode())
- Graph.getRetNode().mergeWith(CallSite.getRetVal());
+ // Recursively traverse all of the callee graphs.
+ const std::vector<DSCallSite> &FunctionCalls = G.getFunctionCalls();
+
+ for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
+ Instruction *CallI = FunctionCalls[i].getCallSite().getInstruction();
+ std::pair<BUDataStructures::ActualCalleesTy::const_iterator,
+ BUDataStructures::ActualCalleesTy::const_iterator>
+ IP = ActualCallees.equal_range(CallI);
+
+ for (BUDataStructures::ActualCalleesTy::const_iterator I = IP.first;
+ I != IP.second; ++I)
+ ComputePostOrder(*I->second, Visited, PostOrder, ActualCallees);
+ }
+
+ PostOrder.push_back(&G);
}
-DSGraph &TDDataStructures::calculateGraph(Function &F) {
- // Make sure this graph has not already been calculated, or that we don't get
- // into an infinite loop with mutually recursive functions.
- //
- DSGraph *&Graph = DSInfo[&F];
- if (Graph) return *Graph;
- BUDataStructures &BU = getAnalysis<BUDataStructures>();
- DSGraph &BUGraph = BU.getDSGraph(F);
-
- // Copy the BU graph, keeping a mapping from the BUGraph to the current Graph
- std::map<const DSNode*, DSNode*> BUNodeMap;
- Graph = new DSGraph(BUGraph, BUNodeMap);
-
- // We only need the BUMap entries for the nodes that are used in call sites.
- // Calculate which nodes are needed.
- std::set<const DSNode*> NeededNodes;
- std::map<const Function*, std::vector<const DSCallSite*> >::iterator CSFFI
- = CallSitesForFunction.find(&F);
- if (CSFFI == CallSitesForFunction.end()) {
- BUNodeMap.clear(); // No nodes are neccesary
- } else {
- std::vector<const DSCallSite*> &CSV = CSFFI->second;
- for (unsigned i = 0, e = CSV.size(); i != e; ++i) {
- NeededNodes.insert(CSV[i]->getRetVal().getNode());
- for (unsigned j = 0, je = CSV[i]->getNumPtrArgs(); j != je; ++j)
- NeededNodes.insert(CSV[i]->getPtrArg(j).getNode());
- }
+
+
+// releaseMemory - If the pass pipeline is done with this pass, we can release
+// our memory... here...
+//
+// FIXME: This should be releaseMemory and will work fine, except that LoadVN
+// has no way to extend the lifetime of the pass, which screws up ds-aa.
+//
+void TDDataStructures::releaseMyMemory() {
+ 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;
}
- // Loop through te BUNodeMap, keeping only the nodes that are "Needed"
- for (std::map<const DSNode*, DSNode*>::iterator I = BUNodeMap.begin();
- I != BUNodeMap.end(); )
- if (NeededNodes.count(I->first) && I->first) // Keep needed nodes...
- ++I;
- else {
- std::map<const DSNode*, DSNode*>::iterator J = I++;
- BUNodeMap.erase(J);
+ // Empty map so next time memory is released, data structures are not
+ // re-deleted.
+ DSInfo.clear();
+ delete GlobalsGraph;
+ GlobalsGraph = 0;
+}
+
+void TDDataStructures::inlineGraphIntoCallees(DSGraph &Graph) {
+ // Recompute the Incomplete markers and eliminate unreachable nodes.
+ Graph.removeTriviallyDeadNodes();
+ Graph.maskIncompleteMarkers();
+
+ // If any of the functions has incomplete incoming arguments, don't mark any
+ // of them as complete.
+ bool HasIncompleteArgs = false;
+ const DSGraph::ReturnNodesTy &GraphReturnNodes = Graph.getReturnNodes();
+ for (DSGraph::ReturnNodesTy::const_iterator I = GraphReturnNodes.begin(),
+ E = GraphReturnNodes.end(); I != E; ++I)
+ if (ArgsRemainIncomplete.count(I->first)) {
+ HasIncompleteArgs = true;
+ break;
}
- NeededNodes.clear(); // We are done with this temporary data structure
+ // Now fold in the necessary globals from the GlobalsGraph. A global G
+ // must be folded in if it exists in the current graph (i.e., is not dead)
+ // and it was not inlined from any of my callers. If it was inlined from
+ // a caller, it would have been fully consistent with the GlobalsGraph
+ // in the caller so folding in is not necessary. Otherwise, this node came
+ // solely from this function's BU graph and so has to be made consistent.
+ //
+ Graph.updateFromGlobalGraph();
+
+ // Recompute the Incomplete markers. Depends on whether args are complete
+ unsigned Flags
+ = HasIncompleteArgs ? DSGraph::MarkFormalArgs : DSGraph::IgnoreFormalArgs;
+ Graph.markIncompleteNodes(Flags | DSGraph::IgnoreGlobals);
- // Convert the mapping from a node-to-node map into a node-to-nodehandle map
- BUNodeMapTy &BUMap = BUMaps[&F];
- BUMap.insert(BUNodeMap.begin(), BUNodeMap.end());
- BUNodeMap.clear(); // We are done with the temporary map.
+ // Delete dead nodes. Treat globals that are unreachable as dead also.
+ Graph.removeDeadNodes(DSGraph::RemoveUnreachableGlobals);
- const std::vector<DSCallSite> *CallSitesP = BU.getCallSites(F);
- if (CallSitesP == 0) {
- DEBUG(std::cerr << " [TD] No callers for: " << F.getName() << "\n");
- return *Graph; // If no call sites, the graph is the same as the BU graph!
+ // We are done with computing the current TD Graph! Now move on to
+ // inlining the current graph into the graphs for its callees, if any.
+ //
+ const std::vector<DSCallSite> &FunctionCalls = Graph.getFunctionCalls();
+ if (FunctionCalls.empty()) {
+ DEBUG(std::cerr << " [TD] No callees for: " << Graph.getFunctionNames()
+ << "\n");
+ return;
}
- // Loop over all call sites of this function, merging each one into this
- // graph.
+ // Now that we have information about all of the callees, propagate the
+ // current graph into the callees. Clone only the reachable subgraph at
+ // each call-site, not the entire graph (even though the entire graph
+ // would be cloned only once, this should still be better on average).
//
- DEBUG(std::cerr << " [TD] Inlining callers for: " << F.getName() << "\n");
- const std::vector<DSCallSite> &CallSites = *CallSitesP;
- for (unsigned c = 0, ce = CallSites.size(); c != ce; ++c) {
- const DSCallSite &CallSite = CallSites[c];
- Function &Caller = *CallSite.getResolvingCaller();
- assert(&Caller && !Caller.isExternal() &&
- "Externals function cannot 'call'!");
-
- DEBUG(std::cerr << "\t [TD] Inlining caller #" << c << " '"
- << Caller.getName() << "' into callee: " << F.getName() << "\n");
-
- // Self recursion is not tracked in BU pass...
- assert(&Caller != &F && "This cannot happen!\n");
-
- // Recursively compute the graph for the Caller. It should be fully
- // resolved except if there is mutual recursion...
- //
- DSGraph &CG = calculateGraph(Caller); // Graph to inline
-
- DEBUG(std::cerr << "\t\t[TD] Got graph for " << Caller.getName()
- << " in: " << F.getName() << "\n");
-
- // Translate call site from having links into the BU graph
- DSCallSite CallSiteInCG(CallSite, BUMaps[&Caller]);
-
- // These two maps keep track of where scalars in the old graph _used_
- // to point to, and of new nodes matching nodes of the old graph.
- std::map<Value*, DSNodeHandle> OldValMap;
- std::map<const DSNode*, DSNode*> OldNodeMap;
-
- // FIXME: Eventually use DSGraph::mergeInGraph here...
- // Graph->mergeInGraph(CallSiteInCG, CG, false);
-
- // Clone the Caller's graph into the current graph, keeping
- // track of where scalars in the old graph _used_ to point...
- // Do this here because it only needs to happens once for each Caller!
- // Strip scalars but not allocas since they are alive in callee.
- //
- DSNodeHandle RetVal = Graph->cloneInto(CG, OldValMap, OldNodeMap,
- DSGraph::KeepAllocaBit);
- ResolveCallSite(*Graph, DSCallSite(CallSiteInCG, OldNodeMap));
+ DEBUG(std::cerr << " [TD] Inlining '" << Graph.getFunctionNames() <<"' into "
+ << FunctionCalls.size() << " call nodes.\n");
+
+ const BUDataStructures::ActualCalleesTy &ActualCallees =
+ getAnalysis<BUDataStructures>().getActualCallees();
+
+ // Loop over all the call sites and all the callees at each call site. Build
+ // a mapping from called DSGraph's to the call sites in this function that
+ // invoke them. This is useful because we can be more efficient if there are
+ // multiple call sites to the callees in the graph from this caller.
+ std::multimap<DSGraph*, std::pair<Function*, const DSCallSite*> > CallSites;
+
+ for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
+ Instruction *CallI = FunctionCalls[i].getCallSite().getInstruction();
+ // For each function in the invoked function list at this call site...
+ std::pair<BUDataStructures::ActualCalleesTy::const_iterator,
+ BUDataStructures::ActualCalleesTy::const_iterator>
+ IP = ActualCallees.equal_range(CallI);
+ // Loop over each actual callee at this call site
+ for (BUDataStructures::ActualCalleesTy::const_iterator I = IP.first;
+ I != IP.second; ++I) {
+ DSGraph& CalleeGraph = getDSGraph(*I->second);
+ assert(&CalleeGraph != &Graph && "TD need not inline graph into self!");
+
+ CallSites.insert(std::make_pair(&CalleeGraph,
+ std::make_pair(I->second, &FunctionCalls[i])));
+ }
}
- // Recompute the Incomplete markers and eliminate unreachable nodes.
- Graph->maskIncompleteMarkers();
- Graph->markIncompleteNodes(/*markFormals*/ !F.hasInternalLinkage()
- /*&& FIXME: NEED TO CHECK IF ALL CALLERS FOUND!*/);
- Graph->removeDeadNodes(/*KeepAllGlobals*/ false, /*KeepCalls*/ false);
+ // Now that we built the mapping, actually perform the inlining a callee graph
+ // at a time.
+ std::multimap<DSGraph*,std::pair<Function*,const DSCallSite*> >::iterator CSI;
+ for (CSI = CallSites.begin(); CSI != CallSites.end(); ) {
+ DSGraph &CalleeGraph = *CSI->first;
+ // Iterate through all of the call sites of this graph, cloning and merging
+ // any nodes required by the call.
+ ReachabilityCloner RC(CalleeGraph, Graph, DSGraph::StripModRefBits);
- DEBUG(std::cerr << " [TD] Done inlining callers for: " << F.getName() << " ["
- << Graph->getGraphSize() << "+" << Graph->getFunctionCalls().size()
- << "]\n");
+ // Clone over any global nodes that appear in both graphs.
+ for (DSGraph::ScalarMapTy::const_iterator
+ SI = CalleeGraph.getScalarMap().begin(),
+ SE = CalleeGraph.getScalarMap().end(); SI != SE; ++SI)
+ if (GlobalValue *GV = dyn_cast<GlobalValue>(SI->first)) {
+ DSGraph::ScalarMapTy::const_iterator GI = Graph.getScalarMap().find(GV);
+ if (GI != Graph.getScalarMap().end())
+ RC.merge(SI->second, GI->second);
+ }
+
+ // Loop over all of the distinct call sites in the caller of the callee.
+ for (; CSI != CallSites.end() && CSI->first == &CalleeGraph; ++CSI) {
+ Function &CF = *CSI->second.first;
+ const DSCallSite &CS = *CSI->second.second;
+ DEBUG(std::cerr << " [TD] Resolving arguments for callee graph '"
+ << CalleeGraph.getFunctionNames()
+ << "': " << CF.getFunctionType()->getNumParams()
+ << " args\n at call site (DSCallSite*) 0x" << &CS << "\n");
+
+ // Get the formal argument and return nodes for the called function and
+ // merge them with the cloned subgraph.
+ RC.mergeCallSite(CalleeGraph.getCallSiteForArguments(CF), CS);
+ ++NumTDInlines;
+ }
+ }
- return *Graph;
+ DEBUG(std::cerr << " [TD] Done inlining into callees for: "
+ << Graph.getFunctionNames() << " [" << Graph.getGraphSize() << "+"
+ << Graph.getFunctionCalls().size() << "]\n");
}