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//===- TopDownClosure.cpp - Compute the top-down interprocedure closure ---===//
//
// This file implements the TDDataStructures class, which represents the
// Top-down Interprocedural closure of the data structure graph over the
// program. This is useful (but not strictly necessary?) for applications
// like pointer analysis.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/DataStructure.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "Support/Statistic.h"
#include "DSCallSiteIterator.h"
namespace {
RegisterAnalysis<TDDataStructures> // Register the pass
Y("tddatastructure", "Top-down Data Structure Analysis");
Statistic<> NumTDInlines("tddatastructures", "Number of graphs inlined");
}
/// FunctionHasCompleteArguments - This function returns true if it is safe not
/// to mark arguments to the function complete.
///
/// FIXME: Need to check if all callers have been found, or rather if a
/// funcpointer escapes!
///
static bool FunctionHasCompleteArguments(Function &F) {
return F.hasInternalLinkage();
}
// 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());
// Figure out which functions must not mark their arguments complete because
// they are accessible outside this compilation unit.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!FunctionHasCompleteArguments(*I))
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 function unreachable function...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
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;
}
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);
// Recursively traverse all of the callee graphs.
const std::vector<DSCallSite> &FunctionCalls = G.getFunctionCalls();
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
std::pair<BUDataStructures::ActualCalleesTy::const_iterator,
BUDataStructures::ActualCalleesTy::const_iterator>
IP = ActualCallees.equal_range(&FunctionCalls[i].getCallInst());
for (BUDataStructures::ActualCalleesTy::const_iterator I = IP.first;
I != IP.second; ++I)
ComputePostOrder(*I->second, Visited, PostOrder, ActualCallees);
}
PostOrder.push_back(&G);
}
// 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;
}
// 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;
}
unsigned Flags
= HasIncompleteArgs ? DSGraph::MarkFormalArgs : DSGraph::IgnoreFormalArgs;
Graph.markIncompleteNodes(Flags | DSGraph::IgnoreGlobals);
Graph.removeDeadNodes(DSGraph::RemoveUnreachableGlobals);
const std::vector<DSCallSite> &FunctionCalls = Graph.getFunctionCalls();
if (FunctionCalls.empty()) {
DEBUG(std::cerr << " [TD] No callees for: " << Graph.getFunctionNames()
<< "\n");
return;
}
// Now that we have information about all of the callees, propagate the
// current graph into the callees.
//
DEBUG(std::cerr << " [TD] Inlining '" << Graph.getFunctionNames() <<"' into "
<< FunctionCalls.size() << " call nodes.\n");
const BUDataStructures::ActualCalleesTy &ActualCallees =
getAnalysis<BUDataStructures>().getActualCallees();
// Only inline this function into each real callee once. After that, just
// merge information into arguments...
hash_map<DSGraph*, DSGraph::NodeMapTy> InlinedSites;
// Loop over all the callees... cloning this graph into each one exactly once,
// keeping track of the node mapping information...
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
// Inline this graph into each function in the invoked function list.
std::pair<BUDataStructures::ActualCalleesTy::const_iterator,
BUDataStructures::ActualCalleesTy::const_iterator>
IP = ActualCallees.equal_range(&FunctionCalls[i].getCallInst());
int NumArgs = 0;
if (IP.first != IP.second) {
NumArgs = IP.first->second->getFunctionType()->getNumParams();
for (BUDataStructures::ActualCalleesTy::const_iterator I = IP.first;
I != IP.second; ++I)
if (NumArgs != (int)I->second->getFunctionType()->getNumParams()) {
NumArgs = -1;
break;
}
}
if (NumArgs == -1) {
std::cerr << "ERROR: NONSAME NUMBER OF ARGUMENTS TO CALLEES\n";
}
for (BUDataStructures::ActualCalleesTy::const_iterator I = IP.first;
I != IP.second; ++I) {
DSGraph &CG = getDSGraph(*I->second);
assert(&CG != &Graph && "TD need not inline graph into self!");
if (!InlinedSites.count(&CG)) { // If we haven't already inlined into CG
DEBUG(std::cerr << " [TD] Inlining graph into callee graph '"
<< CG.getFunctionNames() << "': " << I->second->getFunctionType()->getNumParams() << " args\n");
DSGraph::ScalarMapTy OldScalarMap;
DSGraph::ReturnNodesTy ReturnNodes;
CG.cloneInto(Graph, OldScalarMap, ReturnNodes, InlinedSites[&CG],
DSGraph::StripModRefBits | DSGraph::KeepAllocaBit |
DSGraph::DontCloneCallNodes |
DSGraph::DontCloneAuxCallNodes);
++NumTDInlines;
}
}
}
// Loop over all the callees...
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i) {
// Inline this graph into each function in the invoked function list.
std::pair<BUDataStructures::ActualCalleesTy::const_iterator,
BUDataStructures::ActualCalleesTy::const_iterator>
IP = ActualCallees.equal_range(&FunctionCalls[i].getCallInst());
for (BUDataStructures::ActualCalleesTy::const_iterator I = IP.first;
I != IP.second; ++I) {
DSGraph &CG = getDSGraph(*I->second);
DEBUG(std::cerr << " [TD] Resolving arguments for callee graph '"
<< CG.getFunctionNames() << "'\n");
// Transform our call site information into the cloned version for CG
DSCallSite CS(FunctionCalls[i], InlinedSites[
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