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//===- BottomUpClosure.cpp - Compute the bottom up interprocedure closure -===//
//
// 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.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/DataStructure.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "Support/StatisticReporter.h"
using std::map;
AnalysisID BUDataStructures::ID(AnalysisID::create<BUDataStructures>());
// releaseMemory - If the pass pipeline is done with this pass, we can release
// our memory... here...
//
void BUDataStructures::releaseMemory() {
for (map<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();
}
// 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...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isExternal())
calculateGraph(*I);
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;
}
}
// MergeGlobalNodes - Merge global value nodes in the inlined graph with the
// global value nodes in the current graph if there are duplicates.
//
static void MergeGlobalNodes(map<Value*, DSNodeHandle> &ValMap,
map<Value*, DSNodeHandle> &OldValMap) {
// Loop over all of the nodes inlined, if any of them are global variable
// nodes, we must make sure they get properly added or merged with the ValMap.
//
for (map<Value*, DSNodeHandle>::iterator I = OldValMap.begin(),
E = OldValMap.end(); I != E; ++I)
if (isa<GlobalValue>(I->first)) {
DSNodeHandle &NH = ValMap[I->first]; // Look up global in ValMap.
if (NH == 0) { // No entry for the global yet?
NH = I->second; // Add the one just inlined...
} else {
NH->mergeWith(I->second); // Merge the two globals together.
}
}
}
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;
// Copy the local version into DSInfo...
Graph = new DSGraph(getAnalysis<LocalDataStructures>().getDSGraph(F));
// 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 << "Inlining: " << F.getName() << "\n");
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*> Globals(Call[1]->getGlobals());
// Loop over the functions, inlining whatever we can...
for (unsigned g = 0; g != Globals.size(); ++g) {
// Must be a function type, so this cast MUST succeed.
Function &FI = cast<Function>(*Globals[g]);
if (&FI == &F) {
// Self recursion... simply link up the formal arguments with the
// actual arguments...
DEBUG(std::cerr << "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 globals vector
Globals.erase(Globals.begin()+g--);
} else if (!FI.isExternal()) {
DEBUG(std::cerr << "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 << "Got graph for " << FI.getName() << " in: "
<< F.getName() << "\n");
// Remember the callers for each callee for use in the top-down
// pass so we don't have to compute this again
GI.addCaller(F);
// 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; // unused
// The clone call may invalidate any of the vectors in the data
// structure graph.
DSNode *RetVal = Graph->cloneInto(GI, OldValMap, OldNodeMap);
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->getValueMap(), OldValMap);
// Erase the entry in the globals vector
Globals.erase(Globals.begin()+g--);
} else if (FI.getName() == "printf" || FI.getName() == "sscanf" ||
FI.getName() == "fprintf" || FI.getName() == "open" ||
FI.getName() == "sprintf") {
// Erase the entry in the globals vector
Globals.erase(Globals.begin()+g--);
}
}
if (Globals.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 (Globals.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;
}
}
}
// 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());
return *Graph;
}
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