diff --git a/llvm/include/llvm/Analysis/LazyCallGraph.h b/llvm/include/llvm/Analysis/LazyCallGraph.h index 8ca6b7622730..b129fd0f616d 100644 --- a/llvm/include/llvm/Analysis/LazyCallGraph.h +++ b/llvm/include/llvm/Analysis/LazyCallGraph.h @@ -795,26 +795,25 @@ public: /// though, so be careful calling this while iterating over them. void removeOutgoingEdge(Node &SourceN, Node &TargetN); - /// Remove a ref edge which is entirely within this RefSCC. + /// Remove a list of ref edges which are entirely within this RefSCC. /// - /// Both the \a SourceN and the \a TargetN must be within this RefSCC. - /// Removing such an edge may break cycles that form this RefSCC and thus - /// this operation may change the RefSCC graph significantly. In + /// Both the \a SourceN and all of the \a TargetNs must be within this + /// RefSCC. Removing these edges may break cycles that form this RefSCC and + /// thus this operation may change the RefSCC graph significantly. In /// particular, this operation will re-form new RefSCCs based on the /// remaining connectivity of the graph. The following invariants are /// guaranteed to hold after calling this method: /// - /// 1) This RefSCC is still a RefSCC in the graph. - /// 2) This RefSCC will be the parent of any new RefSCCs. Thus, this RefSCC - /// is preserved as the root of any new RefSCC DAG formed. - /// 3) No RefSCC other than this RefSCC has its member set changed (this is + /// 1) If a ref-cycle remains after removal, it leaves this RefSCC intact + /// and in the graph. No new RefSCCs are built. + /// 2) Otherwise, this RefSCC will be dead after this call and no longer in + /// the graph or the postorder traversal of the call graph. Any iterator + /// pointing at this RefSCC will become invalid. + /// 3) All newly formed RefSCCs will be returned and the order of the + /// RefSCCs returned will be a valid postorder traversal of the new + /// RefSCCs. + /// 4) No RefSCC other than this RefSCC has its member set changed (this is /// inherent in the definition of removing such an edge). - /// 4) All of the parent links of the RefSCC graph will be updated to - /// reflect the new RefSCC structure. - /// 5) All RefSCCs formed out of this RefSCC, excluding this RefSCC, will - /// be returned in post-order. - /// 6) The order of the RefSCCs in the vector will be a valid postorder - /// traversal of the new RefSCCs. /// /// These invariants are very important to ensure that we can build /// optimization pipelines on top of the CGSCC pass manager which @@ -833,11 +832,9 @@ public: /// within this RefSCC and edges from this RefSCC to child RefSCCs. Some /// effort has been made to minimize the overhead of common cases such as /// self-edges and edge removals which result in a spanning tree with no - /// more cycles. There are also detailed comments within the implementation - /// on techniques which could substantially improve this routine's - /// efficiency. + /// more cycles. SmallVector removeInternalRefEdge(Node &SourceN, - Node &TargetN); + ArrayRef TargetNs); /// A convenience wrapper around the above to handle trivial cases of /// inserting a new call edge. diff --git a/llvm/lib/Analysis/CGSCCPassManager.cpp b/llvm/lib/Analysis/CGSCCPassManager.cpp index b81069559c74..ce8af7551477 100644 --- a/llvm/lib/Analysis/CGSCCPassManager.cpp +++ b/llvm/lib/Analysis/CGSCCPassManager.cpp @@ -459,71 +459,78 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass( VisitRef(*F); // First remove all of the edges that are no longer present in this function. - // We have to build a list of dead targets first and then remove them as the - // data structures will all be invalidated by removing them. - SmallVector, 4> DeadTargets; - for (Edge &E : *N) - if (!RetainedEdges.count(&E.getNode())) - DeadTargets.push_back({&E.getNode(), E.getKind()}); - for (auto DeadTarget : DeadTargets) { - Node &TargetN = *DeadTarget.getPointer(); - bool IsCall = DeadTarget.getInt() == Edge::Call; - SCC &TargetC = *G.lookupSCC(TargetN); - RefSCC &TargetRC = TargetC.getOuterRefSCC(); - - if (&TargetRC != RC) { - RC->removeOutgoingEdge(N, TargetN); - if (DebugLogging) - dbgs() << "Deleting outgoing edge from '" << N << "' to '" << TargetN - << "'\n"; + // The first step makes these edges uniformly ref edges and accumulates them + // into a separate data structure so removal doesn't invalidate anything. + SmallVector DeadTargets; + for (Edge &E : *N) { + if (RetainedEdges.count(&E.getNode())) continue; - } - if (DebugLogging) - dbgs() << "Deleting internal " << (IsCall ? "call" : "ref") - << " edge from '" << N << "' to '" << TargetN << "'\n"; - if (IsCall) { + SCC &TargetC = *G.lookupSCC(E.getNode()); + RefSCC &TargetRC = TargetC.getOuterRefSCC(); + if (&TargetRC == RC && E.isCall()) { if (C != &TargetC) { // For separate SCCs this is trivial. - RC->switchTrivialInternalEdgeToRef(N, TargetN); + RC->switchTrivialInternalEdgeToRef(N, E.getNode()); } else { // Now update the call graph. - C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, TargetN), G, - N, C, AM, UR, DebugLogging); + C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, E.getNode()), + G, N, C, AM, UR, DebugLogging); } } - auto NewRefSCCs = RC->removeInternalRefEdge(N, TargetN); - if (!NewRefSCCs.empty()) { - // Note that we don't bother to invalidate analyses as ref-edge - // connectivity is not really observable in any way and is intended - // exclusively to be used for ordering of transforms rather than for - // analysis conclusions. + // Now that this is ready for actual removal, put it into our list. + DeadTargets.push_back(&E.getNode()); + } + // Remove the easy cases quickly and actually pull them out of our list. + DeadTargets.erase( + llvm::remove_if(DeadTargets, + [&](Node *TargetN) { + SCC &TargetC = *G.lookupSCC(*TargetN); + RefSCC &TargetRC = TargetC.getOuterRefSCC(); - // The RC worklist is in reverse postorder, so we first enqueue the - // current RefSCC as it will remain the parent of all split RefSCCs, then - // we enqueue the new ones in RPO except for the one which contains the - // source node as that is the "bottom" we will continue processing in the - // bottom-up walk. - UR.RCWorklist.insert(RC); + // We can't trivially remove internal targets, so skip + // those. + if (&TargetRC == RC) + return false; + + RC->removeOutgoingEdge(N, *TargetN); + if (DebugLogging) + dbgs() << "Deleting outgoing edge from '" << N + << "' to '" << TargetN << "'\n"; + return true; + }), + DeadTargets.end()); + + // Now do a batch removal of the internal ref edges left. + auto NewRefSCCs = RC->removeInternalRefEdge(N, DeadTargets); + if (!NewRefSCCs.empty()) { + // The old RefSCC is dead, mark it as such. + UR.InvalidatedRefSCCs.insert(RC); + + // Note that we don't bother to invalidate analyses as ref-edge + // connectivity is not really observable in any way and is intended + // exclusively to be used for ordering of transforms rather than for + // analysis conclusions. + + // Update RC to the "bottom". + assert(G.lookupSCC(N) == C && "Changed the SCC when splitting RefSCCs!"); + RC = &C->getOuterRefSCC(); + assert(G.lookupRefSCC(N) == RC && "Failed to update current RefSCC!"); + + // The RC worklist is in reverse postorder, so we enqueue the new ones in + // RPO except for the one which contains the source node as that is the + // "bottom" we will continue processing in the bottom-up walk. + assert(NewRefSCCs.front() == RC && + "New current RefSCC not first in the returned list!"); + for (RefSCC *NewRC : + reverse(make_range(std::next(NewRefSCCs.begin()), NewRefSCCs.end()))) { + assert(NewRC != RC && "Should not encounter the current RefSCC further " + "in the postorder list of new RefSCCs."); + UR.RCWorklist.insert(NewRC); if (DebugLogging) - dbgs() << "Enqueuing the existing RefSCC in the update worklist: " - << *RC << "\n"; - // Update the RC to the "bottom". - assert(G.lookupSCC(N) == C && "Changed the SCC when splitting RefSCCs!"); - RC = &C->getOuterRefSCC(); - assert(G.lookupRefSCC(N) == RC && "Failed to update current RefSCC!"); - assert(NewRefSCCs.front() == RC && - "New current RefSCC not first in the returned list!"); - for (RefSCC *NewRC : reverse( - make_range(std::next(NewRefSCCs.begin()), NewRefSCCs.end()))) { - assert(NewRC != RC && "Should not encounter the current RefSCC further " - "in the postorder list of new RefSCCs."); - UR.RCWorklist.insert(NewRC); - if (DebugLogging) - dbgs() << "Enqueuing a new RefSCC in the update worklist: " << *NewRC - << "\n"; - } + dbgs() << "Enqueuing a new RefSCC in the update worklist: " << *NewRC + << "\n"; } } diff --git a/llvm/lib/Analysis/LazyCallGraph.cpp b/llvm/lib/Analysis/LazyCallGraph.cpp index da09426a0632..17e96e758409 100644 --- a/llvm/lib/Analysis/LazyCallGraph.cpp +++ b/llvm/lib/Analysis/LazyCallGraph.cpp @@ -1094,34 +1094,49 @@ void LazyCallGraph::RefSCC::removeOutgoingEdge(Node &SourceN, Node &TargetN) { } SmallVector -LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, Node &TargetN) { - assert(!(*SourceN)[TargetN].isCall() && - "Cannot remove a call edge, it must first be made a ref edge"); - -#ifndef NDEBUG - // In a debug build, verify the RefSCC is valid to start with and when this - // routine finishes. - verify(); - auto VerifyOnExit = make_scope_exit([&]() { verify(); }); -#endif - - // First remove the actual edge. - bool Removed = SourceN->removeEdgeInternal(TargetN); - (void)Removed; - assert(Removed && "Target not in the edge set for this caller?"); - +LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, + ArrayRef TargetNs) { // We return a list of the resulting *new* RefSCCs in post-order. SmallVector Result; - // Direct recursion doesn't impact the SCC graph at all. - if (&SourceN == &TargetN) +#ifndef NDEBUG + // In a debug build, verify the RefSCC is valid to start with and that either + // we return an empty list of result RefSCCs and this RefSCC remains valid, + // or we return new RefSCCs and this RefSCC is dead. + verify(); + auto VerifyOnExit = make_scope_exit([&]() { + if (Result.empty()) { + verify(); + } else { + assert(!G && "A dead RefSCC should have its graph pointer nulled."); + assert(SCCs.empty() && "A dead RefSCC should have no SCCs in it."); + for (RefSCC *RC : Result) + RC->verify(); + } + }); +#endif + + // First remove the actual edges. + for (Node *TargetN : TargetNs) { + assert(!(*SourceN)[*TargetN].isCall() && + "Cannot remove a call edge, it must first be made a ref edge"); + + bool Removed = SourceN->removeEdgeInternal(*TargetN); + (void)Removed; + assert(Removed && "Target not in the edge set for this caller?"); + } + + // Direct self references don't impact the ref graph at all. + if (llvm::all_of(TargetNs, + [&](Node *TargetN) { return &SourceN == TargetN; })) return Result; - // If this ref edge is within an SCC then there are sufficient other edges to - // form a cycle without this edge so removing it is a no-op. + // If all targets are in the same SCC as the source, because no call edges + // were removed there is no RefSCC structure change. SCC &SourceC = *G->lookupSCC(SourceN); - SCC &TargetC = *G->lookupSCC(TargetN); - if (&SourceC == &TargetC) + if (llvm::all_of(TargetNs, [&](Node *TargetN) { + return G->lookupSCC(*TargetN) == &SourceC; + })) return Result; // We build somewhat synthetic new RefSCCs by providing a postorder mapping @@ -1129,33 +1144,13 @@ LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, Node &TargetN) { // than SCCs because this saves a round-trip through the node->SCC map and in // the common case, SCCs are small. We will verify that we always give the // same number to every node in the SCC such that these are equivalent. - const int RootPostOrderNumber = 0; - int PostOrderNumber = RootPostOrderNumber + 1; + int PostOrderNumber = 0; SmallDenseMap PostOrderMapping; - // Every node in the target SCC can already reach every node in this RefSCC - // (by definition). It is the only node we know will stay inside this RefSCC. - // Everything which transitively reaches Target will also remain in the - // RefSCC. We handle this by pre-marking that the nodes in the target SCC map - // back to the root post order number. - // - // This also enables us to take a very significant short-cut in the standard - // Tarjan walk to re-form RefSCCs below: whenever we build an edge that - // references the target node, we know that the target node eventually - // references all other nodes in our walk. As a consequence, we can detect - // and handle participants in that cycle without walking all the edges that - // form the connections, and instead by relying on the fundamental guarantee - // coming into this operation. - for (Node &N : TargetC) - PostOrderMapping[&N] = RootPostOrderNumber; - // Reset all the other nodes to prepare for a DFS over them, and add them to // our worklist. SmallVector Worklist; for (SCC *C : SCCs) { - if (C == &TargetC) - continue; - for (Node &N : *C) N.DFSNumber = N.LowLink = 0; @@ -1212,26 +1207,6 @@ LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, Node &TargetN) { continue; } if (ChildN.DFSNumber == -1) { - // Check if this edge's target node connects to the deleted edge's - // target node. If so, we know that every node connected will end up - // in this RefSCC, so collapse the entire current stack into the root - // slot in our SCC numbering. See above for the motivation of - // optimizing the target connected nodes in this way. - auto PostOrderI = PostOrderMapping.find(&ChildN); - if (PostOrderI != PostOrderMapping.end() && - PostOrderI->second == RootPostOrderNumber) { - MarkNodeForSCCNumber(*N, RootPostOrderNumber); - while (!PendingRefSCCStack.empty()) - MarkNodeForSCCNumber(*PendingRefSCCStack.pop_back_val(), - RootPostOrderNumber); - while (!DFSStack.empty()) - MarkNodeForSCCNumber(*DFSStack.pop_back_val().first, - RootPostOrderNumber); - // Ensure we break all the way out of the enclosing loop. - N = nullptr; - break; - } - // If this child isn't currently in this RefSCC, no need to process // it. ++I; @@ -1246,9 +1221,6 @@ LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, Node &TargetN) { N->LowLink = ChildN.LowLink; ++I; } - if (!N) - // We short-circuited this node. - break; // We've finished processing N and its descendents, put it on our pending // stack to eventually get merged into a RefSCC. @@ -1287,32 +1259,31 @@ LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, Node &TargetN) { assert(PendingRefSCCStack.empty() && "Didn't flush all pending nodes!"); } while (!Worklist.empty()); - // We now have a post-order numbering for RefSCCs and a mapping from each - // node in this RefSCC to its final RefSCC. We create each new RefSCC node - // (re-using this RefSCC node for the root) and build a radix-sort style map - // from postorder number to the RefSCC. We then append SCCs to each of these - // RefSCCs in the order they occured in the original SCCs container. - for (int i = 1; i < PostOrderNumber; ++i) + // If we only ever needed one post-order number, we reformed a ref-cycle for + // every node so the RefSCC remains unchanged. + if (PostOrderNumber == 1) + return Result; + + // Otherwise we create a collection of new RefSCC nodes and build + // a radix-sort style map from postorder number to these new RefSCCs. We then + // append SCCs to each of these RefSCCs in the order they occured in the + // original SCCs container. + for (int i = 0; i < PostOrderNumber; ++i) Result.push_back(G->createRefSCC(*G)); // Insert the resulting postorder sequence into the global graph postorder - // sequence before the current RefSCC in that sequence. The idea being that - // this RefSCC is the target of the reference edge removed, and thus has - // a direct or indirect edge to every other RefSCC formed and so must be at - // the end of any postorder traversal. + // sequence before the current RefSCC in that sequence, and then remove the + // current one. // // FIXME: It'd be nice to change the APIs so that we returned an iterator // range over the global postorder sequence and generally use that sequence // rather than building a separate result vector here. - if (!Result.empty()) { - int Idx = G->getRefSCCIndex(*this); - G->PostOrderRefSCCs.insert(G->PostOrderRefSCCs.begin() + Idx, - Result.begin(), Result.end()); - for (int i : seq(Idx, G->PostOrderRefSCCs.size())) - G->RefSCCIndices[G->PostOrderRefSCCs[i]] = i; - assert(G->PostOrderRefSCCs[G->getRefSCCIndex(*this)] == this && - "Failed to update this RefSCC's index after insertion!"); - } + int Idx = G->getRefSCCIndex(*this); + G->PostOrderRefSCCs.erase(G->PostOrderRefSCCs.begin() + Idx); + G->PostOrderRefSCCs.insert(G->PostOrderRefSCCs.begin() + Idx, Result.begin(), + Result.end()); + for (int i : seq(Idx, G->PostOrderRefSCCs.size())) + G->RefSCCIndices[G->PostOrderRefSCCs[i]] = i; for (SCC *C : SCCs) { auto PostOrderI = PostOrderMapping.find(&*C->begin()); @@ -1324,33 +1295,19 @@ LazyCallGraph::RefSCC::removeInternalRefEdge(Node &SourceN, Node &TargetN) { assert(PostOrderMapping.find(&N)->second == SCCNumber && "Cannot have different numbers for nodes in the same SCC!"); #endif - if (SCCNumber == 0) - // The root node is handled separately by removing the SCCs. - continue; - RefSCC &RC = *Result[SCCNumber - 1]; + RefSCC &RC = *Result[SCCNumber]; int SCCIndex = RC.SCCs.size(); RC.SCCs.push_back(C); RC.SCCIndices[C] = SCCIndex; C->OuterRefSCC = &RC; } - // Now erase all but the root's SCCs. - SCCs.erase(remove_if(SCCs, - [&](SCC *C) { - return PostOrderMapping.lookup(&*C->begin()) != - RootPostOrderNumber; - }), - SCCs.end()); + // Now that we've moved things into the new RefSCCs, clear out our current + // one. + G = nullptr; + SCCs.clear(); SCCIndices.clear(); - for (int i = 0, Size = SCCs.size(); i < Size; ++i) - SCCIndices[SCCs[i]] = i; - -#ifndef NDEBUG - // Verify all of the new RefSCCs. - for (RefSCC *RC : Result) - RC->verify(); -#endif // Return the new list of SCCs. return Result; diff --git a/llvm/unittests/Analysis/LazyCallGraphTest.cpp b/llvm/unittests/Analysis/LazyCallGraphTest.cpp index 9e7e128bcfb3..cb8eb3756059 100644 --- a/llvm/unittests/Analysis/LazyCallGraphTest.cpp +++ b/llvm/unittests/Analysis/LazyCallGraphTest.cpp @@ -1166,20 +1166,21 @@ TEST(LazyCallGraphTest, InlineAndDeleteFunction) { LazyCallGraph::SCC &NewDC = *NewCs.begin(); EXPECT_EQ(&NewDC, CG.lookupSCC(D1)); EXPECT_EQ(&NewDC, CG.lookupSCC(D3)); - auto NewRCs = DRC.removeInternalRefEdge(D1, D2); - EXPECT_EQ(&DRC, CG.lookupRefSCC(D2)); - EXPECT_EQ(NewRCs.end(), std::next(NewRCs.begin())); - LazyCallGraph::RefSCC &NewDRC = **NewRCs.begin(); + auto NewRCs = DRC.removeInternalRefEdge(D1, {&D2}); + ASSERT_EQ(2u, NewRCs.size()); + LazyCallGraph::RefSCC &NewDRC = *NewRCs[0]; EXPECT_EQ(&NewDRC, CG.lookupRefSCC(D1)); EXPECT_EQ(&NewDRC, CG.lookupRefSCC(D3)); - EXPECT_FALSE(NewDRC.isParentOf(DRC)); - EXPECT_TRUE(CRC.isParentOf(DRC)); + LazyCallGraph::RefSCC &D2RC = *NewRCs[1]; + EXPECT_EQ(&D2RC, CG.lookupRefSCC(D2)); + EXPECT_FALSE(NewDRC.isParentOf(D2RC)); + EXPECT_TRUE(CRC.isParentOf(D2RC)); EXPECT_TRUE(CRC.isParentOf(NewDRC)); - EXPECT_TRUE(DRC.isParentOf(NewDRC)); + EXPECT_TRUE(D2RC.isParentOf(NewDRC)); CRC.removeOutgoingEdge(C1, D2); - EXPECT_FALSE(CRC.isParentOf(DRC)); + EXPECT_FALSE(CRC.isParentOf(D2RC)); EXPECT_TRUE(CRC.isParentOf(NewDRC)); - EXPECT_TRUE(DRC.isParentOf(NewDRC)); + EXPECT_TRUE(D2RC.isParentOf(NewDRC)); // Now that we've updated the call graph, D2 is dead, so remove it. CG.removeDeadFunction(D2F); @@ -1340,7 +1341,7 @@ TEST(LazyCallGraphTest, InternalEdgeRemoval) { // Remove the edge from b -> a, which should leave the 3 functions still in // a single connected component because of a -> b -> c -> a. SmallVector NewRCs = - RC.removeInternalRefEdge(B, A); + RC.removeInternalRefEdge(B, {&A}); EXPECT_EQ(0u, NewRCs.size()); EXPECT_EQ(&RC, CG.lookupRefSCC(A)); EXPECT_EQ(&RC, CG.lookupRefSCC(B)); @@ -1350,24 +1351,94 @@ TEST(LazyCallGraphTest, InternalEdgeRemoval) { EXPECT_EQ(&RC, &*J); EXPECT_EQ(E, std::next(J)); + // Increment I before we actually mutate the structure so that it remains + // a valid iterator. + ++I; + // Remove the edge from c -> a, which should leave 'a' in the original RefSCC // and form a new RefSCC for 'b' and 'c'. - NewRCs = RC.removeInternalRefEdge(C, A); - EXPECT_EQ(1u, NewRCs.size()); - EXPECT_EQ(&RC, CG.lookupRefSCC(A)); - EXPECT_EQ(1, std::distance(RC.begin(), RC.end())); - LazyCallGraph::RefSCC &RC2 = *CG.lookupRefSCC(B); - EXPECT_EQ(&RC2, CG.lookupRefSCC(C)); - EXPECT_EQ(&RC2, NewRCs[0]); + NewRCs = RC.removeInternalRefEdge(C, {&A}); + ASSERT_EQ(2u, NewRCs.size()); + LazyCallGraph::RefSCC &BCRC = *NewRCs[0]; + LazyCallGraph::RefSCC &ARC = *NewRCs[1]; + EXPECT_EQ(&ARC, CG.lookupRefSCC(A)); + EXPECT_EQ(1, std::distance(ARC.begin(), ARC.end())); + EXPECT_EQ(&BCRC, CG.lookupRefSCC(B)); + EXPECT_EQ(&BCRC, CG.lookupRefSCC(C)); J = CG.postorder_ref_scc_begin(); EXPECT_NE(I, J); - EXPECT_EQ(&RC2, &*J); + EXPECT_EQ(&BCRC, &*J); + ++J; + EXPECT_NE(I, J); + EXPECT_EQ(&ARC, &*J); ++J; EXPECT_EQ(I, J); - EXPECT_EQ(&RC, &*J); + EXPECT_EQ(E, J); +} + +TEST(LazyCallGraphTest, InternalMultiEdgeRemoval) { + LLVMContext Context; + // A nice fully connected (including self-edges) RefSCC. + std::unique_ptr M = parseAssembly( + Context, "define void @a(i8** %ptr) {\n" + "entry:\n" + " store i8* bitcast (void(i8**)* @a to i8*), i8** %ptr\n" + " store i8* bitcast (void(i8**)* @b to i8*), i8** %ptr\n" + " store i8* bitcast (void(i8**)* @c to i8*), i8** %ptr\n" + " ret void\n" + "}\n" + "define void @b(i8** %ptr) {\n" + "entry:\n" + " store i8* bitcast (void(i8**)* @a to i8*), i8** %ptr\n" + " store i8* bitcast (void(i8**)* @b to i8*), i8** %ptr\n" + " store i8* bitcast (void(i8**)* @c to i8*), i8** %ptr\n" + " ret void\n" + "}\n" + "define void @c(i8** %ptr) {\n" + "entry:\n" + " store i8* bitcast (void(i8**)* @a to i8*), i8** %ptr\n" + " store i8* bitcast (void(i8**)* @b to i8*), i8** %ptr\n" + " store i8* bitcast (void(i8**)* @c to i8*), i8** %ptr\n" + " ret void\n" + "}\n"); + LazyCallGraph CG = buildCG(*M); + + // Force the graph to be fully expanded. + CG.buildRefSCCs(); + auto I = CG.postorder_ref_scc_begin(), E = CG.postorder_ref_scc_end(); + LazyCallGraph::RefSCC &RC = *I; + EXPECT_EQ(E, std::next(I)); + + LazyCallGraph::Node &A = *CG.lookup(lookupFunction(*M, "a")); + LazyCallGraph::Node &B = *CG.lookup(lookupFunction(*M, "b")); + LazyCallGraph::Node &C = *CG.lookup(lookupFunction(*M, "c")); + EXPECT_EQ(&RC, CG.lookupRefSCC(A)); + EXPECT_EQ(&RC, CG.lookupRefSCC(B)); + EXPECT_EQ(&RC, CG.lookupRefSCC(C)); + + // Increment I before we actually mutate the structure so that it remains + // a valid iterator. ++I; - EXPECT_EQ(E, I); + + // Remove the edges from b -> a and b -> c, leaving b in its own RefSCC. + SmallVector NewRCs = + RC.removeInternalRefEdge(B, {&A, &C}); + + ASSERT_EQ(2u, NewRCs.size()); + LazyCallGraph::RefSCC &BRC = *NewRCs[0]; + LazyCallGraph::RefSCC &ACRC = *NewRCs[1]; + EXPECT_EQ(&BRC, CG.lookupRefSCC(B)); + EXPECT_EQ(1, std::distance(BRC.begin(), BRC.end())); + EXPECT_EQ(&ACRC, CG.lookupRefSCC(A)); + EXPECT_EQ(&ACRC, CG.lookupRefSCC(C)); + auto J = CG.postorder_ref_scc_begin(); + EXPECT_NE(I, J); + EXPECT_EQ(&BRC, &*J); ++J; + EXPECT_NE(I, J); + EXPECT_EQ(&ACRC, &*J); + ++J; + EXPECT_EQ(I, J); EXPECT_EQ(E, J); } @@ -1420,7 +1491,7 @@ TEST(LazyCallGraphTest, InternalNoOpEdgeRemoval) { // Remove the edge from a -> c which doesn't change anything. SmallVector NewRCs = - RC.removeInternalRefEdge(AN, CN); + RC.removeInternalRefEdge(AN, {&CN}); EXPECT_EQ(0u, NewRCs.size()); EXPECT_EQ(&RC, CG.lookupRefSCC(AN)); EXPECT_EQ(&RC, CG.lookupRefSCC(BN)); @@ -1435,8 +1506,8 @@ TEST(LazyCallGraphTest, InternalNoOpEdgeRemoval) { // Remove the edge from b -> a and c -> b; again this doesn't change // anything. - NewRCs = RC.removeInternalRefEdge(BN, AN); - NewRCs = RC.removeInternalRefEdge(CN, BN); + NewRCs = RC.removeInternalRefEdge(BN, {&AN}); + NewRCs = RC.removeInternalRefEdge(CN, {&BN}); EXPECT_EQ(0u, NewRCs.size()); EXPECT_EQ(&RC, CG.lookupRefSCC(AN)); EXPECT_EQ(&RC, CG.lookupRefSCC(BN));