//===- 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
//
//===----------------------------------------------------------------------===//
-#include "llvm/Analysis/DataStructure.h"
-#include "llvm/Analysis/DSGraph.h"
+#include "llvm/Analysis/DataStructure/DataStructure.h"
#include "llvm/Module.h"
#include "Support/Statistic.h"
-using std::map;
-
-static RegisterAnalysis<BUDataStructures>
-X("budatastructure", "Bottom-up Data Structure Analysis Closure");
+#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;
// program.
//
bool BUDataStructures::run(Module &M) {
- GlobalsGraph = new DSGraph();
+ LocalDataStructures &LocalDSA = getAnalysis<LocalDataStructures>();
+ GlobalsGraph = new DSGraph(LocalDSA.getGlobalsGraph());
+ GlobalsGraph->setPrintAuxCalls();
+
+ Function *MainFunc = M.getMainFunction();
+ if (MainFunc)
+ calculateReachableGraphs(MainFunc);
- // Simply calculate the graphs for each function...
+ // 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, 0);
+ 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;
}
-// 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;
+void BUDataStructures::calculateReachableGraphs(Function *F) {
+ std::vector<Function*> Stack;
+ hash_map<Function*, unsigned> ValMap;
+ unsigned NextID = 1;
+ calculateGraphs(F, Stack, NextID, ValMap);
+}
- // Empty map so next time memory is released, data structures are not
- // re-deleted.
- DSInfo.clear();
- delete GlobalsGraph;
- GlobalsGraph = 0;
+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;
+ }
-// Return true if a graph was inlined
-// Can not modify the part of the AuxCallList < FirstResolvableCall.
-//
-bool BUDataStructures::ResolveFunctionCalls(DSGraph &G,
- unsigned &FirstResolvableCall,
- std::map<Function*, DSCallSite> &InProcess,
- unsigned Indent) {
- std::vector<DSCallSite> &FCs = G.getAuxFunctionCalls();
- bool Changed = false;
-
- // Loop while there are call sites that we can resolve!
- while (FirstResolvableCall != FCs.size()) {
- DSCallSite Call = FCs[FirstResolvableCall];
-
- // If the function list is incomplete...
- if (Call.getCallee().getNode()->NodeType & DSNode::Incomplete) {
- // If incomplete, we cannot resolve it, so leave it at the beginning of
- // the call list with the other unresolvable calls...
- ++FirstResolvableCall;
+ 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 {
- // Start inlining all of the functions we can... some may not be
- // inlinable if they are external...
- //
- const std::vector<GlobalValue*> &Callees =
- Call.getCallee().getNode()->getGlobals();
-
- bool hasExternalTarget = false;
-
- // Loop over the functions, inlining whatever we can...
- for (unsigned c = 0, e = Callees.size(); c != e; ++c) {
- // Must be a function type, so this cast should succeed unless something
- // really wierd is happening.
- Function &FI = cast<Function>(*Callees[c]);
-
- if (FI.getName() == "printf" || FI.getName() == "sscanf" ||
- FI.getName() == "fprintf" || FI.getName() == "open" ||
- FI.getName() == "sprintf" || FI.getName() == "fputs") {
- // Ignore
- } else if (FI.isExternal()) {
- // If the function is external, then we cannot resolve this call site!
- hasExternalTarget = true;
- break;
- } else {
- std::map<Function*, DSCallSite>::iterator I =
- InProcess.lower_bound(&FI);
-
- if (I != InProcess.end() && I->first == &FI) { // Recursion detected?
- // Merge two call sites to eliminate recursion...
- Call.mergeWith(I->second);
-
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "* Recursion detected for function " << FI.getName()<<"\n");
- } else {
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "Inlining: " << FI.getName() << "\n");
-
- // Get the data structure graph for the called function, closing it
- // if possible...
- //
- DSGraph &GI = calculateGraph(FI, Indent+1); // Graph to inline
-
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "Got graph for: " << FI.getName() << "["
- << GI.getGraphSize() << "+"
- << GI.getAuxFunctionCalls().size() << "] "
- << " in: " << G.getFunction().getName() << "["
- << G.getGraphSize() << "+"
- << G.getAuxFunctionCalls().size() << "]\n");
-
- // Keep track of how many call sites are added by the inlining...
- unsigned NumCalls = FCs.size();
-
- // Resolve the arguments and return value
- G.mergeInGraph(Call, GI, DSGraph::StripAllocaBit |
- DSGraph::DontCloneCallNodes);
-
- // Added a call site?
- if (FCs.size() != NumCalls) {
- // Otherwise we need to inline the graph. Temporarily add the
- // current function to the InProcess map to be able to handle
- // recursion successfully.
- //
- I = InProcess.insert(I, std::make_pair(&FI, Call));
-
- // ResolveFunctionCalls - Resolve the function calls that just got
- // inlined...
- //
- Changed |= ResolveFunctionCalls(G, NumCalls, InProcess, Indent+1);
-
- // Now that we are done processing the inlined graph, remove our
- // cycle detector record...
- //
- //InProcess.erase(I);
- }
- }
+ 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);
}
- }
-
- if (hasExternalTarget) {
- // If we cannot resolve this call site...
- ++FirstResolvableCall;
- } else {
- Changed = true;
- FCs.erase(FCs.begin()+FirstResolvableCall);
+ // 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 Changed;
+ return MyID; // == Min
}
-DSGraph &BUDataStructures::calculateGraph(Function &F, unsigned Indent) {
- // Make sure this graph has not already been calculated, or that we don't get
- // into an infinite loop with mutually recursive functions.
- //
- DSGraph *&GraphPtr = DSInfo[&F];
- if (GraphPtr) return *GraphPtr;
- // Copy the local version into DSInfo...
- GraphPtr = new DSGraph(getAnalysis<LocalDataStructures>().getDSGraph(F));
- DSGraph &Graph = *GraphPtr;
+// 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;
+ }
- Graph.setGlobalsGraph(GlobalsGraph);
- Graph.setPrintAuxCalls();
+ // Empty map so next time memory is released, data structures are not
+ // re-deleted.
+ DSInfo.clear();
+ delete GlobalsGraph;
+ GlobalsGraph = 0;
+}
- // Start resolving calls...
- std::vector<DSCallSite> &FCs = Graph.getAuxFunctionCalls();
+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();
- // Start with a copy of the original call sites...
- FCs = Graph.getFunctionCalls();
-
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "[BU] Calculating graph for: " << F.getName() << "\n");
-
- bool Changed;
- while (1) {
- unsigned FirstResolvableCall = 0;
- std::map<Function *, DSCallSite> InProcess;
-
- // Insert a call site for self to handle self recursion...
- std::vector<DSNodeHandle> Args;
- Args.reserve(F.asize());
- for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
- if (isPointerType(I->getType()))
- Args.push_back(Graph.getNodeForValue(I));
-
- InProcess.insert(std::make_pair(&F,
- DSCallSite(*(CallInst*)0, Graph.getRetNode(),(DSNode*)0,Args)));
-
- Changed = ResolveFunctionCalls(Graph, FirstResolvableCall, InProcess,
- Indent);
-
- if (Changed) {
- Graph.maskIncompleteMarkers();
- Graph.markIncompleteNodes();
- Graph.removeDeadNodes();
- break;
- } else {
- break;
- }
- }
+ 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");
-#if 0
- bool Inlined;
- do {
- Inlined = false;
-
- for (unsigned i = 0; i != FCs.size(); ++i) {
- // Copy the call, because inlining graphs may invalidate the FCs vector.
- DSCallSite Call = FCs[i];
-
- // If the function list is complete...
- if ((Call.getCallee().getNode()->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.getCallee().getNode()->getGlobals();
-
- unsigned OldNumCalls = FCs.size();
-
- // 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 << std::string(Indent*2, ' ')
- << "[BU] Self Inlining: " << F.getName() << "\n");
-
- // Handle self recursion by resolving the arguments and return value
- Graph.mergeInGraph(Call, Graph, DSGraph::StripAllocaBit);
-
- // Erase the entry in the callees vector
- Callees.erase(Callees.begin()+c--);
-
- } else if (!FI.isExternal()) {
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "[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, Indent+1); // Graph to inline
-
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "[BU] Got graph for " << FI.getName()
- << " in: " << F.getName() << "[" << GI.getGraphSize() << "+"
- << GI.getAuxFunctionCalls().size() << "]\n");
-
- // Handle self recursion by resolving the arguments and return value
- Graph.mergeInGraph(Call, GI, DSGraph::StripAllocaBit |
- DSGraph::DontCloneCallNodes);
-
- // 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" || FI.getName() == "fputs") {
- // FIXME: These special cases (eg printf) should go away when we can
- // define functions that take a variable number of arguments.
-
- // FIXME: at the very least, this should update mod/ref info
- // Erase the entry in the globals vector
- Callees.erase(Callees.begin()+c--);
- }
- }
+ // Handle self recursion by resolving the arguments and return value
+ Graph.mergeInGraph(CS, *Callee, Graph, 0);
- 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.getCallee().getNode()->getGlobals().size()) {
- // Was able to inline SOME, but not all of the functions. Construct a
- // new global node here.
- //
- assert(0 && "Unimpl!");
- Inlined = true;
- }
+ } 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
- // If we just inlined a function that had call nodes, chances are that
- // the call nodes are redundant with ones we already have. Eliminate
- // those call nodes now.
- //
- if (FCs.size() >= OldNumCalls)
- Graph.removeTriviallyDeadNodes();
+ Graph.writeGraphToFile(std::cerr, "bu_" + F.getName() + "_after_" +
+ Callee->getName());
#endif
- }
+ }
+ }
- if (FCs.size() > 200) {
- std::cerr << "Aborted inlining fn: '" << F.getName() << "'!"
- << std::endl;
- Graph.maskIncompleteMarkers();
- Graph.markIncompleteNodes();
- Graph.removeDeadNodes();
- Graph.writeGraphToFile(std::cerr, "crap."+F.getName());
- exit(1);
- return Graph;
- }
+ // 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. If there are any function calls left
- // now that are complete, we must loop!
- if (Inlined) {
- Graph.maskIncompleteMarkers();
- Graph.markIncompleteNodes();
- Graph.removeDeadNodes();
- }
-
- } while (Inlined && !FCs.empty());
-#endif
+ // 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);
- DEBUG(std::cerr << std::string(Indent*2, ' ')
- << "[BU] Done inlining: " << F.getName() << " ["
- << Graph.getGraphSize() << "+" << Graph.getAuxFunctionCalls().size()
- << "]\n");
+ // 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);
- Graph.writeGraphToFile(std::cerr, "bu_" + F.getName());
+ // 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]);
- return Graph;
+ //Graph.writeGraphToFile(std::cerr, "bu_" + F.getName());
}
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