-//===- BottomUpClosure.cpp - Compute the bottom up interprocedure closure -===//
+//===- 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 pointer analysis.
+// applications like alias analysis.
//
//===----------------------------------------------------------------------===//
-#include "llvm/Analysis/DataStructure.h"
+#include "llvm/Analysis/DataStructure/DataStructure.h"
#include "llvm/Module.h"
-#include "llvm/DerivedTypes.h"
-#include "Support/StatisticReporter.h"
-#include <set>
-using std::map;
-
-static RegisterAnalysis<BUDataStructures>
-X("budatastructure", "Bottom-up Data Structure Analysis Closure");
-AnalysisID BUDataStructures::ID = X;
-
-// releaseMemory - If the pass pipeline is done with this pass, we can release
-// our memory... here...
-//
-void BUDataStructures::releaseMemory() {
- for (map<const Function*, DSGraph*>::iterator I = DSInfo.begin(),
- E = DSInfo.end(); I != E; ++I)
- delete I->second;
-
- // Empty map so next time memory is released, data structures are not
- // re-deleted.
- DSInfo.clear();
+#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) {
- // Simply calculate the graphs for each function...
+ 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())
- calculateGraph(*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;
}
-
-// ResolveArguments - Resolve the formal and actual arguments for a function
-// call.
-//
-static void ResolveArguments(std::vector<DSNodeHandle> &Call, Function &F,
- map<Value*, DSNodeHandle> &ValueMap) {
- // Resolve all of the function arguments...
- Function::aiterator AI = F.abegin();
- for (unsigned i = 2, e = Call.size(); i != e; ++i) {
- // Advance the argument iterator to the first pointer argument...
- while (!isa<PointerType>(AI->getType())) ++AI;
-
- // Add the link from the argument scalar to the provided value
- DSNode *NN = ValueMap[AI];
- NN->addEdgeTo(Call[i]);
- ++AI;
- }
+void BUDataStructures::calculateReachableGraphs(Function *F) {
+ std::vector<Function*> Stack;
+ hash_map<Function*, unsigned> ValMap;
+ unsigned NextID = 1;
+ calculateGraphs(F, Stack, NextID, ValMap);
}
-// MergeGlobalNodes - Merge all existing global nodes with globals
-// inlined from the callee or with globals from the GlobalsGraph.
-//
-static void MergeGlobalNodes(DSGraph& Graph,
- map<Value*, DSNodeHandle> &OldValMap) {
- map<Value*, DSNodeHandle> &ValMap = Graph.getValueMap();
- for (map<Value*, DSNodeHandle>::iterator I = ValMap.begin(), E = ValMap.end();
- I != E; ++I)
- if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
- map<Value*, DSNodeHandle>:: iterator NHI = OldValMap.find(GV);
- if (NHI != OldValMap.end()) // was it inlined from the callee?
- I->second->mergeWith(NHI->second);
- else // get it from the GlobalsGraph
- I->second->mergeWith(Graph.cloneGlobalInto(GV));
- }
+DSGraph &BUDataStructures::getOrCreateGraph(Function *F) {
+ // Has the graph already been created?
+ DSGraph *&Graph = DSInfo[F];
+ if (Graph) return *Graph;
- // Add unused inlined global nodes into the value map
- for (map<Value*, DSNodeHandle>::iterator I = OldValMap.begin(),
- E = OldValMap.end(); I != E; ++I)
- if (isa<GlobalValue>(I->first)) {
- DSNodeHandle &NH = ValMap[I->first]; // If global is not in ValMap...
- if (NH == 0)
- NH = I->second; // Add the one just inlined.
- }
+ // 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;
}
-DSGraph &BUDataStructures::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;
+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;
+ }
- // Copy the local version into DSInfo...
- Graph = new DSGraph(getAnalysis<LocalDataStructures>().getDSGraph(F));
-
- // Populate the GlobalsGraph with globals from this one.
- Graph->GlobalsGraph->cloneGlobals(*Graph, /*cloneCalls*/ false);
-
- // Save a copy of the original call nodes for the top-down pass
- Graph->saveOrigFunctionCalls();
-
- // Start resolving calls...
- std::vector<std::vector<DSNodeHandle> > &FCs = Graph->getFunctionCalls();
-
- DEBUG(std::cerr << " [BU] Inlining: " << F.getName() << "\n");
-
- // Add F to the PendingCallers list of each direct callee for use in the
- // top-down pass so we don't have to compute this again. We don't want
- // to do it for indirect callees inlined later, so remember which calls
- // are in the original FCs set.
- std::set<const DSNode*> directCallees;
- for (unsigned i = 0; i < FCs.size(); ++i)
- directCallees.insert(FCs[i][1]); // ptr to function node
-
- bool Inlined;
- do {
- Inlined = false;
-
- for (unsigned i = 0; i != FCs.size(); ++i) {
- // Copy the call, because inlining graphs may invalidate the FCs vector.
- std::vector<DSNodeHandle> Call = FCs[i];
-
- // If the function list is not incomplete...
- if ((Call[1]->NodeType & DSNode::Incomplete) == 0) {
- // Start inlining all of the functions we can... some may not be
- // inlinable if they are external...
- //
- std::vector<GlobalValue*> Callees(Call[1]->getGlobals());
-
- // Loop over the functions, inlining whatever we can...
- for (unsigned c = 0; c != Callees.size(); ++c) {
- // Must be a function type, so this cast MUST succeed.
- Function &FI = cast<Function>(*Callees[c]);
- if (&FI == &F) {
- // Self recursion... simply link up the formal arguments with the
- // actual arguments...
-
- DEBUG(std::cerr << "\t[BU] Self Inlining: " << F.getName() << "\n");
-
- if (Call[0]) // Handle the return value if present...
- Graph->RetNode->mergeWith(Call[0]);
-
- // Resolve the arguments in the call to the actual values...
- ResolveArguments(Call, F, Graph->getValueMap());
-
- // Erase the entry in the callees vector
- Callees.erase(Callees.begin()+c--);
- } else if (!FI.isExternal()) {
- DEBUG(std::cerr << "\t[BU] In " << F.getName() << " inlining: "
- << FI.getName() << "\n");
-
- // Get the data structure graph for the called function, closing it
- // if possible (which is only impossible in the case of mutual
- // recursion...
- //
- DSGraph &GI = calculateGraph(FI); // Graph to inline
-
- DEBUG(std::cerr << "\t\t[BU] Got graph for " << FI.getName()
- << " in: " << F.getName() << "\n");
-
- // Clone the callee's graph into the current graph, keeping
- // track of where scalars in the old graph _used_ to point,
- // and of the new nodes matching nodes of the old graph.
- std::map<Value*, DSNodeHandle> OldValMap;
- std::map<const DSNode*, DSNode*> OldNodeMap;
-
- // The clone call may invalidate any of the vectors in the data
- // structure graph. Strip locals and don't copy the list of callers
- DSNode *RetVal = Graph->cloneInto(GI, OldValMap, OldNodeMap,
- /*StripScalars*/ true,
- /*StripAllocas*/ true,
- /*CopyCallers*/ false,
- /*CopyOrigCalls*/ false);
-
- ResolveArguments(Call, FI, OldValMap);
-
- if (Call[0]) // Handle the return value if present
- RetVal->mergeWith(Call[0]);
-
- // Merge global value nodes in the inlined graph with the global
- // value nodes in the current graph if there are duplicates.
- //
- MergeGlobalNodes(*Graph, OldValMap);
-
- // If this was an original call, add F to the PendingCallers list
- if (directCallees.find(Call[1]) != directCallees.end())
- GI.addCaller(F);
-
- // Erase the entry in the Callees vector
- Callees.erase(Callees.begin()+c--);
-
- } else if (FI.getName() == "printf" || FI.getName() == "sscanf" ||
- FI.getName() == "fprintf" || FI.getName() == "open" ||
- FI.getName() == "sprintf") {
-
- // Erase the entry in the globals vector
- Callees.erase(Callees.begin()+c--);
- }
- }
+ 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;
+ }
- if (Callees.empty()) { // Inlined all of the function calls?
- // Erase the call if it is resolvable...
- FCs.erase(FCs.begin()+i--); // Don't skip a the next call...
- Inlined = true;
- } else if (Callees.size() != Call[1]->getGlobals().size()) {
- // Was able to inline SOME, but not all of the functions. Construct a
- // new global node here.
- //
- assert(0 && "Unimpl!");
- Inlined = true;
+ 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;
}
}
- // Recompute the Incomplete markers. If there are any function calls left
- // now that are complete, we must loop!
- if (Inlined) {
- Graph->maskIncompleteMarkers();
- Graph->markIncompleteNodes();
- Graph->removeDeadNodes(/*KeepAllGlobals*/ false, /*KeepCalls*/ true);
+ // 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
}
- } while (Inlined && !FCs.empty());
+ }
- // Copy any unresolved call nodes into the Globals graph and
- // filter out unresolved call nodes inlined from the callee.
- if (!FCs.empty())
- Graph->GlobalsGraph->cloneCalls(*Graph);
+ // Make sure to catch any leftover unresolvable calls...
+ for (++LastCallSiteIdx; LastCallSiteIdx < TempFCs.size(); ++LastCallSiteIdx)
+ AuxCallsList.push_back(TempFCs[LastCallSiteIdx]);
- Graph->maskIncompleteMarkers();
- Graph->markIncompleteNodes();
- Graph->removeDeadNodes(/*KeepAllGlobals*/ false, /*KeepCalls*/ false);
+ TempFCs.clear();
- DEBUG(std::cerr << " [BU] Done inlining: " << F.getName() << " ["
- << Graph->getGraphSize() << "+" << Graph->getFunctionCalls().size()
- << "]\n");
+ // Recompute the Incomplete markers
+ assert(Graph.getInlinedGlobals().empty());
+ Graph.maskIncompleteMarkers();
+ Graph.markIncompleteNodes(DSGraph::MarkFormalArgs);
- return *Graph;
+ // 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());
}
projects / oota-llvm.git / blobdiff