Initial checkin of Datastructure analysis.
Has bugs, but shouldn't crash in theory.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1994 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/ComputeClosure.cpp b/lib/Analysis/DataStructure/ComputeClosure.cpp
new file mode 100644
index 0000000..93ba1a8
--- /dev/null
+++ b/lib/Analysis/DataStructure/ComputeClosure.cpp
@@ -0,0 +1,265 @@
+//===- ComputeClosure.cpp - Implement interprocedural closing of graphs ---===//
+//
+// Compute the interprocedural closure of a data structure graph
+//
+//===----------------------------------------------------------------------===//
+
+// DEBUG_IP_CLOSURE - Define this to debug the act of linking up graphs
+//#define DEBUG_IP_CLOSURE 1
+
+#include "llvm/Analysis/DataStructure.h"
+#include "llvm/iOther.h"
+#include "Support/STLExtras.h"
+#include <algorithm>
+#ifdef DEBUG_IP_CLOSURE
+#include "llvm/Assembly/Writer.h"
+#endif
+
+// copyEdgesFromTo - Make a copy of all of the edges to Node to also point
+// PV. If there are edges out of Node, the edges are added to the subgraph
+// starting at PV.
+//
+static void copyEdgesFromTo(DSNode *Node, const PointerValSet &PVS) {
+ // Make all of the pointers that pointed to Node now also point to PV...
+ const vector<PointerValSet*> &PVSToUpdate(Node->getReferrers());
+ for (unsigned i = 0, e = PVSToUpdate.size(); i != e; ++i)
+ for (unsigned pn = 0, pne = PVS.size(); pn != pne; ++pn)
+ PVSToUpdate[i]->add(PVS[pn]);
+}
+
+static void CalculateNodeMapping(ShadowDSNode *Shadow, DSNode *Node,
+ multimap<ShadowDSNode *, DSNode *> &NodeMapping) {
+#ifdef DEBUG_IP_CLOSURE
+ cerr << "Mapping " << (void*)Shadow << " to " << (void*)Node << "\n";
+ cerr << "Type = '" << Shadow->getType() << "' and '"
+ << Node->getType() << "'\n";
+ cerr << "Shadow Node:\n";
+ Shadow->print(cerr);
+ cerr << "\nMapped Node:\n";
+ Node->print(cerr);
+#endif
+ assert(Shadow->getType() == Node->getType() &&
+ "Shadow and mapped nodes disagree about type!");
+
+ multimap<ShadowDSNode *, DSNode *>::iterator
+ NI = NodeMapping.lower_bound(Shadow),
+ NE = NodeMapping.upper_bound(Shadow);
+
+ for (; NI != NE; ++NI)
+ if (NI->second == Node) return; // Already processed node, return.
+
+ NodeMapping.insert(make_pair(Shadow, Node)); // Add a mapping...
+
+ // Loop over all of the outgoing links in the shadow node...
+ //
+ assert(Node->getNumLinks() == Shadow->getNumLinks() &&
+ "Same type, but different number of links?");
+ for (unsigned i = 0, e = Shadow->getNumLinks(); i != e; ++i) {
+ PointerValSet &Link = Shadow->getLink(i);
+
+ // Loop over all of the values coming out of this pointer...
+ for (unsigned l = 0, le = Link.size(); l != le; ++l) {
+ // If the outgoing node points to a shadow node, map the shadow node to
+ // all of the outgoing values in Node.
+ //
+ if (ShadowDSNode *ShadOut = dyn_cast<ShadowDSNode>(Link[l].Node)) {
+ PointerValSet &NLink = Node->getLink(i);
+ for (unsigned ol = 0, ole = NLink.size(); ol != ole; ++ol)
+ CalculateNodeMapping(ShadOut, NLink[ol].Node, NodeMapping);
+ }
+ }
+ }
+}
+
+
+static void ResolveNodesTo(const PointerVal &FromPtr,
+ const PointerValSet &ToVals) {
+ assert(FromPtr.Index == 0 &&
+ "Resolved node return pointer should be index 0!");
+ if (!isa<ShadowDSNode>(FromPtr.Node)) return;
+
+ ShadowDSNode *Shadow = cast<ShadowDSNode>(FromPtr.Node);
+
+ typedef multimap<ShadowDSNode *, DSNode *> ShadNodeMapTy;
+ ShadNodeMapTy NodeMapping;
+ for (unsigned i = 0, e = ToVals.size(); i != e; ++i)
+ CalculateNodeMapping(Shadow, ToVals[i].Node, NodeMapping);
+
+ copyEdgesFromTo(Shadow, ToVals);
+
+ // Now loop through the shadow node graph, mirroring the edges in the shadow
+ // graph onto the realized graph...
+ //
+ for (ShadNodeMapTy::iterator I = NodeMapping.begin(),
+ E = NodeMapping.end(); I != E; ++I) {
+ DSNode *Node = I->second;
+ ShadowDSNode *ShadNode = I->first;
+
+ // Must loop over edges in the shadow graph, adding edges in the real graph
+ // that correspond to to the edges, but are mapped into real values by the
+ // NodeMapping.
+ //
+ for (unsigned i = 0, e = Node->getNumLinks(); i != e; ++i) {
+ const PointerValSet &ShadLinks = ShadNode->getLink(i);
+ PointerValSet &NewLinks = Node->getLink(i);
+
+ // Add a link to all of the nodes pointed to by the shadow field...
+ for (unsigned l = 0, le = ShadLinks.size(); l != le; ++l) {
+ DSNode *ShadLink = ShadLinks[l].Node;
+
+ if (ShadowDSNode *SL = dyn_cast<ShadowDSNode>(ShadLink)) {
+ // Loop over all of the values in the range
+ ShadNodeMapTy::iterator St = NodeMapping.lower_bound(SL),
+ En = NodeMapping.upper_bound(SL);
+ if (St != En) {
+ for (; St != En; ++St)
+ NewLinks.add(PointerVal(St->second, ShadLinks[l].Index));
+ } else {
+ // We must retain the shadow node...
+ NewLinks.add(ShadLinks[l]);
+ }
+ } else {
+ // Otherwise, add a direct link to the data structure pointed to by
+ // the shadow node...
+ NewLinks.add(ShadLinks[l]);
+ }
+ }
+ }
+ }
+}
+
+
+// ResolveNodeTo - The specified node is now known to point to the set of values
+// in ToVals, instead of the old shadow node subgraph that it was pointing to.
+//
+static void ResolveNodeTo(DSNode *Node, const PointerValSet &ToVals) {
+ assert(Node->getNumLinks() == 1 && "Resolved node can only be a scalar!!");
+
+ PointerValSet PVS = Node->getLink(0);
+
+ for (unsigned i = 0, e = PVS.size(); i != e; ++i)
+ ResolveNodesTo(PVS[i], ToVals);
+}
+
+// isResolvableCallNode - Return true if node is a call node and it is a call
+// node that we can inline...
+//
+static bool isResolvableCallNode(DSNode *N) {
+ // Only operate on call nodes...
+ CallDSNode *CN = dyn_cast<CallDSNode>(N);
+ if (CN == 0) return false;
+
+ // Only operate on call nodes with direct method calls
+ Function *F = CN->getCall()->getCalledFunction();
+ if (F == 0) return false;
+
+ // Only work on call nodes with direct calls to methods with bodies.
+ return !F->isExternal();
+}
+
+
+// computeClosure - Replace all of the resolvable call nodes with the contents
+// of their corresponding method data structure graph...
+//
+void FunctionDSGraph::computeClosure(const DataStructure &DS) {
+ vector<DSNode*>::iterator NI = std::find_if(Nodes.begin(), Nodes.end(),
+ isResolvableCallNode);
+
+ map<Function*, unsigned> InlineCount; // FIXME
+
+ // Loop over the resolvable call nodes...
+ while (NI != Nodes.end()) {
+ CallDSNode *CN = cast<CallDSNode>(*NI);
+ Function *F = CN->getCall()->getCalledFunction();
+ //if (F == Func) return; // Do not do self inlining
+
+ // FIXME: Gross hack to prevent explosions when inlining a recursive func.
+ if (InlineCount[F]++ > 2) return;
+
+ Nodes.erase(NI); // Remove the call node from the graph
+
+ unsigned CallNodeOffset = NI-Nodes.begin();
+
+ // StartNode - The first node of the incorporated graph, last node of the
+ // preexisting data structure graph...
+ //
+ unsigned StartNode = Nodes.size();
+
+ // Hold the set of values that correspond to the incorporated methods
+ // return set.
+ //
+ PointerValSet RetVals;
+
+ if (F != Func) { // If this is not a recursive call...
+ // Get the datastructure graph for the new method. Note that we are not
+ // allowed to modify this graph because it will be the cached graph that
+ // is returned by other users that want the local datastructure graph for
+ // a method.
+ //
+ const FunctionDSGraph &NewFunction = DS.getDSGraph(F);
+
+ // Incorporate a copy of the called function graph into the current graph,
+ // allowing us to do local transformations to local graph to link
+ // arguments to call values, and call node to return value...
+ //
+ RetVals = cloneFunctionIntoSelf(NewFunction, false);
+
+ } else { // We are looking at a recursive function!
+ StartNode = 0; // Arg nodes start at 0 now...
+ RetVals = RetNode;
+ }
+
+ // If the function returns a pointer value... Resolve values pointing to
+ // the shadow nodes pointed to by CN to now point the values in RetVals...
+ //
+ if (CN->getNumLinks()) ResolveNodeTo(CN, RetVals);
+
+ // If the call node has arguments, process them now!
+ if (CN->getNumArgs()) {
+ // The ArgNodes of the incorporated graph should be the nodes starting at
+ // StartNode, ordered the same way as the call arguments. The arg nodes
+ // are seperated by a single shadow node, so we need to be sure to step
+ // over them.
+ //
+ unsigned ArgOffset = StartNode;
+ for (unsigned i = 0, e = CN->getNumArgs(); i != e; ++i) {
+ // Get the arg node of the incorporated method...
+ ArgDSNode *ArgNode = cast<ArgDSNode>(Nodes[ArgOffset]);
+
+ // Now we make all of the nodes inside of the incorporated method point
+ // to the real arguments values, not to the shadow nodes for the
+ // argument.
+ //
+ ResolveNodeTo(ArgNode, CN->getArgValues(i));
+
+ if (StartNode == 0) { // Self recursion?
+ ArgOffset += 2; // Skip over the argument & the shadow node...
+ } else {
+ // Remove the argnode from the set of nodes in this method...
+ Nodes.erase(Nodes.begin()+ArgOffset);
+
+ // ArgNode is no longer useful, delete now!
+ delete ArgNode;
+
+ ArgOffset++; // Skip over the shadow node for the argument
+ }
+ }
+ }
+
+ // Now the call node is completely destructable. Eliminate it now.
+ delete CN;
+
+ // Eliminate shadow nodes that are not distinguishable from some other
+ // node in the graph...
+ //
+ UnlinkUndistinguishableShadowNodes();
+
+ // Eliminate shadow nodes that are now extraneous due to linking...
+ RemoveUnreachableShadowNodes();
+
+ //if (F == Func) return; // Only do one self inlining
+
+ // Move on to the next call node...
+ NI = std::find_if(Nodes.begin(), Nodes.end(), isResolvableCallNode);
+ }
+}