Avoid referencing deleted DSgraphs when merging an SCC into a larger SCC. This

fixes the crash in 176.gcc.

llvm-svn: 11033
This commit is contained in:
Chris Lattner 2004-01-31 21:02:18 +00:00
parent d1ec5f36ee
commit 89f03df701

View File

@ -152,7 +152,7 @@ unsigned BUDataStructures::calculateGraphs(Function *F,
} else {
// SCCFunctions - Keep track of the functions in the current SCC
//
hash_set<Function*> SCCFunctions;
hash_set<DSGraph*> SCCGraphs;
Function *NF;
std::vector<Function*>::iterator FirstInSCC = Stack.end();
@ -160,36 +160,38 @@ unsigned BUDataStructures::calculateGraphs(Function *F,
do {
NF = *--FirstInSCC;
ValMap[NF] = ~0U;
SCCFunctions.insert(NF);
// 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);
if (!SCCGraph || SCCGraph->getGraphSize() < NFGraph.getGraphSize())
SCCGraph = &NFGraph;
} while (NF != F);
std::cerr << "Calculating graph for SCC #: " << MyID << " of size: "
<< SCCFunctions.size() << "\n";
<< SCCGraphs.size() << "\n";
// Compute the Max SCC Size...
if (MaxSCC < SCCFunctions.size())
MaxSCC = SCCFunctions.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<Function*>::iterator I = SCCFunctions.begin(),
E = SCCFunctions.end(); I != E; ++I) {
DSGraph &G = getDSGraph(**I);
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...
DSInfo[*I] = SCCGraph;
for (DSGraph::ReturnNodesTy::iterator I = G.getReturnNodes().begin(),
E = G.getReturnNodes().end(); I != E; ++I)
DSInfo[I->first] = SCCGraph;
delete &G;
}
}