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Elimiante calls to a node with nothing in it.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4695 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-11-11 21:35:38 +00:00
parent a9c9c0216e
commit e425844d8c
1 changed files with 45 additions and 36 deletions
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81
lib/Analysis/DataStructure/DataStructure.cpp
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@ -808,45 +808,54 @@ static void removeIdenticalCalls(vector<DSCallSite> &Calls,
DSNode *LastCalleeNode = 0;
unsigned NumDuplicateCalls = 0;
bool LastCalleeContainsExternalFunction = false;
for (unsigned i = 0, e = Calls.size(); i != e; ++i) {
for (unsigned i = 0; i != Calls.size(); ++i) {
DSCallSite &CS = Calls[i];
// If the return value or any arguments point to a void node with no
// information at all in it, and the call node is the only node to point
// to it, remove the edge to the node (killing the node).
//
killIfUselessEdge(CS.getRetVal());
for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
killIfUselessEdge(CS.getPtrArg(a));
// If this call site calls the same function as the last call site, and if
// the function pointer contains an external function, this node will never
// be resolved. Merge the arguments of the call node because no information
// will be lost.
//
if (CS.getCallee().getNode() == LastCalleeNode) {
++NumDuplicateCalls;
if (NumDuplicateCalls == 1) {
LastCalleeContainsExternalFunction =
nodeContainsExternalFunction(LastCalleeNode);
}
if (LastCalleeContainsExternalFunction ||
// This should be more than enough context sensitivity!
// FIXME: Evaluate how many times this is tripped!
NumDuplicateCalls > 20) {
DSCallSite &OCS = Calls[i-1];
OCS.mergeWith(CS);
// The node will now be eliminated as a duplicate!
if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
CS = OCS;
else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
OCS = CS;
}
// If the Callee is a useless edge, this must be an unreachable call site,
// eliminate it.
killIfUselessEdge(CS.getCallee());
if (CS.getCallee().getNode() == 0) {
CS.swap(Calls.back());
Calls.pop_back();
--i;
} else {
LastCalleeNode = CS.getCallee().getNode();
NumDuplicateCalls = 0;
// If the return value or any arguments point to a void node with no
// information at all in it, and the call node is the only node to point
// to it, remove the edge to the node (killing the node).
//
killIfUselessEdge(CS.getRetVal());
for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
killIfUselessEdge(CS.getPtrArg(a));
// If this call site calls the same function as the last call site, and if
// the function pointer contains an external function, this node will
// never be resolved. Merge the arguments of the call node because no
// information will be lost.
//
if (CS.getCallee().getNode() == LastCalleeNode) {
++NumDuplicateCalls;
if (NumDuplicateCalls == 1) {
LastCalleeContainsExternalFunction =
nodeContainsExternalFunction(LastCalleeNode);
}
if (LastCalleeContainsExternalFunction ||
// This should be more than enough context sensitivity!
// FIXME: Evaluate how many times this is tripped!
NumDuplicateCalls > 20) {
DSCallSite &OCS = Calls[i-1];
OCS.mergeWith(CS);
// The node will now be eliminated as a duplicate!
if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
CS = OCS;
else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
OCS = CS;
}
} else {
LastCalleeNode = CS.getCallee().getNode();
NumDuplicateCalls = 0;
}
}
}