[llvm] r311015 - [Dominators] Introduce batch updates
Jakub Kuderski via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 16 09:12:52 PDT 2017
Author: kuhar
Date: Wed Aug 16 09:12:52 2017
New Revision: 311015
URL: http://llvm.org/viewvc/llvm-project?rev=311015&view=rev
Log:
[Dominators] Introduce batch updates
Summary:
This patch introduces a way of informing the (Post)DominatorTree about multiple CFG updates that happened since the last tree update. This makes performing tree updates much easier, as it internally takes care of applying the updates in lockstep with the (virtual) updates to the CFG, which is done by reverse-applying future CFG updates.
The batch updater is able to remove redundant updates that cancel each other out. In the future, it should be also possible to reorder updates to reduce the amount of work needed to perform the updates.
Reviewers: dberlin, sanjoy, grosser, davide, brzycki
Reviewed By: brzycki
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D36167
Added:
llvm/trunk/unittests/IR/DominatorTreeBatchUpdatesTest.cpp
Modified:
llvm/trunk/include/llvm/IR/Dominators.h
llvm/trunk/include/llvm/Support/GenericDomTree.h
llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h
llvm/trunk/lib/IR/Dominators.cpp
llvm/trunk/unittests/IR/CMakeLists.txt
Modified: llvm/trunk/include/llvm/IR/Dominators.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Dominators.h?rev=311015&r1=311014&r2=311015&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/Dominators.h (original)
+++ llvm/trunk/include/llvm/IR/Dominators.h Wed Aug 16 09:12:52 2017
@@ -41,6 +41,10 @@ namespace DomTreeBuilder {
using BBDomTree = DomTreeBase<BasicBlock>;
using BBPostDomTree = PostDomTreeBase<BasicBlock>;
+extern template struct Update<BasicBlock *>;
+
+using BBUpdates = ArrayRef<Update<BasicBlock *>>;
+
extern template void Calculate<BBDomTree>(BBDomTree &DT);
extern template void Calculate<BBPostDomTree>(BBPostDomTree &DT);
@@ -56,6 +60,9 @@ extern template void DeleteEdge<BBPostDo
BasicBlock *From,
BasicBlock *To);
+extern template void ApplyUpdates<BBDomTree>(BBDomTree &DT, BBUpdates);
+extern template void ApplyUpdates<BBPostDomTree>(BBPostDomTree &DT, BBUpdates);
+
extern template bool Verify<BBDomTree>(const BBDomTree &DT);
extern template bool Verify<BBPostDomTree>(const BBPostDomTree &DT);
} // namespace DomTreeBuilder
Modified: llvm/trunk/include/llvm/Support/GenericDomTree.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/GenericDomTree.h?rev=311015&r1=311014&r2=311015&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/GenericDomTree.h (original)
+++ llvm/trunk/include/llvm/Support/GenericDomTree.h Wed Aug 16 09:12:52 2017
@@ -24,12 +24,6 @@
#ifndef LLVM_SUPPORT_GENERICDOMTREE_H
#define LLVM_SUPPORT_GENERICDOMTREE_H
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/GraphTraits.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
@@ -38,6 +32,13 @@
#include <type_traits>
#include <utility>
#include <vector>
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/raw_ostream.h"
namespace llvm {
@@ -45,7 +46,7 @@ template <typename NodeT, bool IsPostDom
class DominatorTreeBase;
namespace DomTreeBuilder {
-template <class DomTreeT>
+template <typename DomTreeT>
struct SemiNCAInfo;
} // namespace DomTreeBuilder
@@ -190,14 +191,48 @@ namespace DomTreeBuilder {
template <typename DomTreeT>
void Calculate(DomTreeT &DT);
-template <class DomTreeT>
+template <typename DomTreeT>
void InsertEdge(DomTreeT &DT, typename DomTreeT::NodePtr From,
typename DomTreeT::NodePtr To);
-template <class DomTreeT>
+template <typename DomTreeT>
void DeleteEdge(DomTreeT &DT, typename DomTreeT::NodePtr From,
typename DomTreeT::NodePtr To);
+// UpdateKind and Update are used by the batch update API and it's easiest to
+// define them here.
+enum class UpdateKind : unsigned char { Insert, Delete };
+
+template <typename NodePtr>
+struct Update {
+ using NodeKindPair = PointerIntPair<NodePtr, 1, UpdateKind>;
+
+ NodePtr From;
+ NodeKindPair ToAndKind;
+
+ Update(UpdateKind Kind, NodePtr From, NodePtr To)
+ : From(From), ToAndKind(To, Kind) {}
+
+ UpdateKind getKind() const { return ToAndKind.getInt(); }
+ NodePtr getFrom() const { return From; }
+ NodePtr getTo() const { return ToAndKind.getPointer(); }
+ bool operator==(const Update &RHS) const {
+ return From == RHS.From && ToAndKind == RHS.ToAndKind;
+ }
+
+ friend raw_ostream &operator<<(raw_ostream &OS, const Update &U) {
+ OS << (U.getKind() == UpdateKind::Insert ? "Insert " : "Delete ");
+ U.getFrom()->printAsOperand(OS, false);
+ OS << " -> ";
+ U.getTo()->printAsOperand(OS, false);
+ return OS;
+ }
+};
+
+template <typename DomTreeT>
+void ApplyUpdates(DomTreeT &DT,
+ ArrayRef<typename DomTreeT::UpdateType> Updates);
+
template <typename DomTreeT>
bool Verify(const DomTreeT &DT);
} // namespace DomTreeBuilder
@@ -219,6 +254,11 @@ class DominatorTreeBase {
using ParentType = typename std::remove_pointer<ParentPtr>::type;
static constexpr bool IsPostDominator = IsPostDom;
+ using UpdateType = DomTreeBuilder::Update<NodePtr>;
+ using UpdateKind = DomTreeBuilder::UpdateKind;
+ static constexpr UpdateKind Insert = UpdateKind::Insert;
+ static constexpr UpdateKind Delete = UpdateKind::Delete;
+
protected:
// Dominators always have a single root, postdominators can have more.
SmallVector<NodeT *, IsPostDom ? 4 : 1> Roots;
@@ -463,6 +503,39 @@ class DominatorTreeBase {
// API to update (Post)DominatorTree information based on modifications to
// the CFG...
+ /// Inform the dominator tree about a sequence of CFG edge insertions and
+ /// deletions and perform a batch update on the tree.
+ ///
+ /// This function should be used when there were multiple CFG updates after
+ /// the last dominator tree update. It takes care of performing the updates
+ /// in sync with the CFG and optimizes away the redundant operations that
+ /// cancel each other.
+ /// The functions expects the sequence of updates to be balanced. Eg.:
+ /// - {{Insert, A, B}, {Delete, A, B}, {Insert, A, B}} is fine, because
+ /// logically it results in a single insertions.
+ /// - {{Insert, A, B}, {Insert, A, B}} is invalid, because it doesn't make
+ /// sense to insert the same edge twice.
+ ///
+ /// What's more, the functions assumes that it's safe to ask every node in the
+ /// CFG about its children and inverse children. This implies that deletions
+ /// of CFG edges must not delete the CFG nodes before calling this function.
+ ///
+ /// Batch updates should be generally faster when performing longer sequences
+ /// of updates than calling insertEdge/deleteEdge manually multiple times, as
+ /// they can reorder the updates and remove redundant ones internally.
+ ///
+ /// Note that for postdominators it automatically takes care of applying
+ /// updates on reverse edges internally (so there's no need to swap the
+ /// From and To pointers when constructing DominatorTree::UpdateType).
+ /// The type of updates is the same for DomTreeBase<T> and PostDomTreeBase<T>
+ /// with the same template parameter T.
+ ///
+ /// \param Updates An unordered sequence of updates to perform.
+ ///
+ void applyUpdates(ArrayRef<UpdateType> Updates) {
+ DomTreeBuilder::ApplyUpdates(*this, Updates);
+ }
+
/// Inform the dominator tree about a CFG edge insertion and update the tree.
///
/// This function has to be called just before or just after making the update
@@ -487,11 +560,6 @@ class DominatorTreeBase {
/// DEBUG mode. There cannot be any other updates that the
/// dominator tree doesn't know about.
///
- /// However, it is fine to perform multiple CFG deletions that make different
- /// subtrees forward-unreachable and to inform the DomTree about them all at
- /// the same time, as the incremental algorithm doesn't walk the tree above
- /// the NearestCommonDominator of a deleted edge
- ///
/// Note that for postdominators it automatically takes care of deleting
/// a reverse edge internally (so there's no need to swap the parameters).
///
@@ -678,7 +746,6 @@ public:
/// recalculate - compute a dominator tree for the given function
void recalculate(ParentType &Func) {
- reset();
Parent = &Func;
DomTreeBuilder::Calculate(*this);
}
Modified: llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h?rev=311015&r1=311014&r2=311015&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h (original)
+++ llvm/trunk/include/llvm/Support/GenericDomTreeConstruction.h Wed Aug 16 09:12:52 2017
@@ -34,8 +34,10 @@
#define LLVM_SUPPORT_GENERICDOMTREECONSTRUCTION_H
#include <queue>
+#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GenericDomTree.h"
@@ -45,20 +47,6 @@
namespace llvm {
namespace DomTreeBuilder {
-template <typename NodePtr, bool Inverse>
-struct ChildrenGetter {
- static auto Get(NodePtr N) -> decltype(reverse(children<NodePtr>(N))) {
- return reverse(children<NodePtr>(N));
- }
-};
-
-template <typename NodePtr>
-struct ChildrenGetter<NodePtr, true> {
- static auto Get(NodePtr N) -> decltype(inverse_children<NodePtr>(N)) {
- return inverse_children<NodePtr>(N);
- }
-};
-
template <typename DomTreeT>
struct SemiNCAInfo {
using NodePtr = typename DomTreeT::NodePtr;
@@ -82,11 +70,99 @@ struct SemiNCAInfo {
std::vector<NodePtr> NumToNode = {nullptr};
DenseMap<NodePtr, InfoRec> NodeToInfo;
+ using UpdateT = typename DomTreeT::UpdateType;
+ struct BatchUpdateInfo {
+ SmallVector<UpdateT, 4> Updates;
+ using NodePtrAndKind = PointerIntPair<NodePtr, 1, UpdateKind>;
+
+ // In order to be able to walk a CFG that is out of sync with the CFG
+ // DominatorTree last knew about, use the list of updates to reconstruct
+ // previous CFG versions of the current CFG. For each node, we store a set
+ // of its virtually added/deleted future successors and predecessors.
+ // Note that these children are from the future relative to what the
+ // DominatorTree knows about -- using them to gets us some snapshot of the
+ // CFG from the past (relative to the state of the CFG).
+ DenseMap<NodePtr, SmallDenseSet<NodePtrAndKind, 4>> FutureSuccessors;
+ DenseMap<NodePtr, SmallDenseSet<NodePtrAndKind, 4>> FuturePredecessors;
+ // Remembers if the whole tree was recalculated at some point during the
+ // current batch update.
+ bool IsRecalculated = false;
+ };
+
+ BatchUpdateInfo *BatchUpdates;
+ using BatchUpdatePtr = BatchUpdateInfo *;
+
+ // If BUI is a nullptr, then there's no batch update in progress.
+ SemiNCAInfo(BatchUpdatePtr BUI) : BatchUpdates(BUI) {}
+
void clear() {
NumToNode = {nullptr}; // Restore to initial state with a dummy start node.
NodeToInfo.clear();
+ // Don't reset the pointer to BatchUpdateInfo here -- if there's an update
+ // in progress, we need this information to continue it.
}
+ template <bool Inverse>
+ struct ChildrenGetter {
+ using ResultTy = SmallVector<NodePtr, 8>;
+
+ static ResultTy Get(NodePtr N, std::integral_constant<bool, false>) {
+ auto RChildren = reverse(children<NodePtr>(N));
+ return ResultTy(RChildren.begin(), RChildren.end());
+ }
+
+ static ResultTy Get(NodePtr N, std::integral_constant<bool, true>) {
+ auto IChildren = inverse_children<NodePtr>(N);
+ return ResultTy(IChildren.begin(), IChildren.end());
+ }
+
+ using Tag = std::integral_constant<bool, Inverse>;
+
+ // The function below is the core part of the batch updater. It allows the
+ // Depth Based Search algorithm to perform incremental updates in lockstep
+ // with updates to the CFG. We emulated lockstep CFG updates by getting its
+ // next snapshots by reverse-applying future updates.
+ static ResultTy Get(NodePtr N, BatchUpdatePtr BUI) {
+ ResultTy Res = Get(N, Tag());
+ // If there's no batch update in progress, simply return node's children.
+ if (!BUI) return Res;
+
+ // CFG children are actually its *most current* children, and we have to
+ // reverse-apply the future updates to get the node's children at the
+ // point in time the update was performed.
+ auto &FutureChildren = (Inverse != IsPostDom) ? BUI->FuturePredecessors
+ : BUI->FutureSuccessors;
+ auto FCIt = FutureChildren.find(N);
+ if (FCIt == FutureChildren.end()) return Res;
+
+ for (auto ChildAndKind : FCIt->second) {
+ const NodePtr Child = ChildAndKind.getPointer();
+ const UpdateKind UK = ChildAndKind.getInt();
+
+ // Reverse-apply the future update.
+ if (UK == UpdateKind::Insert) {
+ // If there's an insertion in the future, it means that the edge must
+ // exist in the current CFG, but was not present in it before.
+ assert(llvm::find(Res, Child) != Res.end()
+ && "Expected child not found in the CFG");
+ Res.erase(std::remove(Res.begin(), Res.end(), Child), Res.end());
+ DEBUG(dbgs() << "\tHiding edge " << BlockNamePrinter(N) << " -> "
+ << BlockNamePrinter(Child) << "\n");
+ } else {
+ // If there's an deletion in the future, it means that the edge cannot
+ // exist in the current CFG, but existed in it before.
+ assert(llvm::find(Res, Child) == Res.end() &&
+ "Unexpected child found in the CFG");
+ DEBUG(dbgs() << "\tShowing virtual edge " << BlockNamePrinter(N)
+ << " -> " << BlockNamePrinter(Child) << "\n");
+ Res.push_back(Child);
+ }
+ }
+
+ return Res;
+ }
+ };
+
NodePtr getIDom(NodePtr BB) const {
auto InfoIt = NodeToInfo.find(BB);
if (InfoIt == NodeToInfo.end()) return nullptr;
@@ -154,7 +230,8 @@ struct SemiNCAInfo {
NumToNode.push_back(BB);
constexpr bool Direction = IsReverse != IsPostDom; // XOR.
- for (const NodePtr Succ : ChildrenGetter<NodePtr, Direction>::Get(BB)) {
+ for (const NodePtr Succ :
+ ChildrenGetter<Direction>::Get(BB, BatchUpdates)) {
const auto SIT = NodeToInfo.find(Succ);
// Don't visit nodes more than once but remember to collect
// ReverseChildren.
@@ -281,10 +358,9 @@ struct SemiNCAInfo {
// For postdominators, nodes with no forward successors are trivial roots that
// are always selected as tree roots. Roots with forward successors correspond
// to CFG nodes within infinite loops.
- static bool HasForwardSuccessors(const NodePtr N) {
+ static bool HasForwardSuccessors(const NodePtr N, BatchUpdatePtr BUI) {
assert(N && "N must be a valid node");
- using TraitsTy = GraphTraits<typename DomTreeT::ParentPtr>;
- return TraitsTy::child_begin(N) != TraitsTy::child_end(N);
+ return !ChildrenGetter<false>::Get(N, BUI).empty();
}
static NodePtr GetEntryNode(const DomTreeT &DT) {
@@ -295,7 +371,7 @@ struct SemiNCAInfo {
// Finds all roots without relaying on the set of roots already stored in the
// tree.
// We define roots to be some non-redundant set of the CFG nodes
- static RootsT FindRoots(const DomTreeT &DT) {
+ static RootsT FindRoots(const DomTreeT &DT, BatchUpdatePtr BUI) {
assert(DT.Parent && "Parent pointer is not set");
RootsT Roots;
@@ -305,7 +381,7 @@ struct SemiNCAInfo {
return Roots;
}
- SemiNCAInfo SNCA;
+ SemiNCAInfo SNCA(BUI);
// PostDominatorTree always has a virtual root.
SNCA.addVirtualRoot();
@@ -316,10 +392,15 @@ struct SemiNCAInfo {
// Step #1: Find all the trivial roots that are going to will definitely
// remain tree roots.
unsigned Total = 0;
+ // It may happen that there are some new nodes in the CFG that are result of
+ // the ongoing batch update, but we cannot really pretend that they don't
+ // exist -- we won't see any outgoing or incoming edges to them, so it's
+ // fine to discover them here, as they would end up appearing in the CFG at
+ // some point anyway.
for (const NodePtr N : nodes(DT.Parent)) {
++Total;
// If it has no *successors*, it is definitely a root.
- if (!HasForwardSuccessors(N)) {
+ if (!HasForwardSuccessors(N, BUI)) {
Roots.push_back(N);
// Run DFS not to walk this part of CFG later.
Num = SNCA.runDFS(N, Num, AlwaysDescend, 1);
@@ -398,7 +479,7 @@ struct SemiNCAInfo {
assert((Total + 1 == Num) && "Everything should have been visited");
// Step #3: If we found some non-trivial roots, make them non-redundant.
- if (HasNonTrivialRoots) RemoveRedundantRoots(DT, Roots);
+ if (HasNonTrivialRoots) RemoveRedundantRoots(DT, BUI, Roots);
DEBUG(dbgs() << "Found roots: ");
DEBUG(for (auto *Root : Roots) dbgs() << BlockNamePrinter(Root) << " ");
@@ -415,16 +496,17 @@ struct SemiNCAInfo {
// the non-trivial roots are reverse-reachable from other non-trivial roots,
// which makes them redundant. This function removes them from the set of
// input roots.
- static void RemoveRedundantRoots(const DomTreeT &DT, RootsT &Roots) {
+ static void RemoveRedundantRoots(const DomTreeT &DT, BatchUpdatePtr BUI,
+ RootsT &Roots) {
assert(IsPostDom && "This function is for postdominators only");
DEBUG(dbgs() << "Removing redundant roots\n");
- SemiNCAInfo SNCA;
+ SemiNCAInfo SNCA(BUI);
for (unsigned i = 0; i < Roots.size(); ++i) {
auto &Root = Roots[i];
// Trivial roots are always non-redundant.
- if (!HasForwardSuccessors(Root)) continue;
+ if (!HasForwardSuccessors(Root, BUI)) continue;
DEBUG(dbgs() << "\tChecking if " << BlockNamePrinter(Root)
<< " remains a root\n");
SNCA.clear();
@@ -466,13 +548,23 @@ struct SemiNCAInfo {
for (const NodePtr Root : DT.Roots) Num = runDFS(Root, Num, DC, 0);
}
- void calculateFromScratch(DomTreeT &DT) {
+ static void CalculateFromScratch(DomTreeT &DT, BatchUpdatePtr BUI) {
+ auto *Parent = DT.Parent;
+ DT.reset();
+ DT.Parent = Parent;
+ SemiNCAInfo SNCA(nullptr); // Since we are rebuilding the whole tree,
+ // there's no point doing it incrementally.
+
// Step #0: Number blocks in depth-first order and initialize variables used
// in later stages of the algorithm.
- DT.Roots = FindRoots(DT);
- doFullDFSWalk(DT, AlwaysDescend);
+ DT.Roots = FindRoots(DT, nullptr);
+ SNCA.doFullDFSWalk(DT, AlwaysDescend);
- runSemiNCA(DT);
+ SNCA.runSemiNCA(DT);
+ if (BUI) {
+ BUI->IsRecalculated = true;
+ DEBUG(dbgs() << "DomTree recalculated, skipping future batch updates\n");
+ }
if (DT.Roots.empty()) return;
@@ -484,7 +576,7 @@ struct SemiNCAInfo {
DT.RootNode = (DT.DomTreeNodes[Root] =
llvm::make_unique<DomTreeNodeBase<NodeT>>(Root, nullptr))
.get();
- attachNewSubtree(DT, DT.RootNode);
+ SNCA.attachNewSubtree(DT, DT.RootNode);
}
void attachNewSubtree(DomTreeT& DT, const TreeNodePtr AttachTo) {
@@ -541,7 +633,8 @@ struct SemiNCAInfo {
SmallVector<TreeNodePtr, 8> VisitedNotAffectedQueue;
};
- static void InsertEdge(DomTreeT &DT, const NodePtr From, const NodePtr To) {
+ static void InsertEdge(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const NodePtr From, const NodePtr To) {
assert((From || IsPostDom) &&
"From has to be a valid CFG node or a virtual root");
assert(To && "Cannot be a nullptr");
@@ -566,14 +659,15 @@ struct SemiNCAInfo {
const TreeNodePtr ToTN = DT.getNode(To);
if (!ToTN)
- InsertUnreachable(DT, FromTN, To);
+ InsertUnreachable(DT, BUI, FromTN, To);
else
- InsertReachable(DT, FromTN, ToTN);
+ InsertReachable(DT, BUI, FromTN, ToTN);
}
// Determines if some existing root becomes reverse-reachable after the
// insertion. Rebuilds the whole tree if that situation happens.
- static bool UpdateRootsBeforeInsertion(DomTreeT &DT, const TreeNodePtr From,
+ static bool UpdateRootsBeforeInsertion(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr From,
const TreeNodePtr To) {
assert(IsPostDom && "This function is only for postdominators");
// Destination node is not attached to the virtual root, so it cannot be a
@@ -587,22 +681,24 @@ struct SemiNCAInfo {
DEBUG(dbgs() << "\t\tAfter the insertion, " << BlockNamePrinter(To)
<< " is no longer a root\n\t\tRebuilding the tree!!!\n");
- DT.recalculate(*DT.Parent);
+ CalculateFromScratch(DT, BUI);
return true;
}
// Updates the set of roots after insertion or deletion. This ensures that
// roots are the same when after a series of updates and when the tree would
// be built from scratch.
- static void UpdateRootsAfterUpdate(DomTreeT &DT) {
+ static void UpdateRootsAfterUpdate(DomTreeT &DT, const BatchUpdatePtr BUI) {
assert(IsPostDom && "This function is only for postdominators");
// The tree has only trivial roots -- nothing to update.
- if (std::none_of(DT.Roots.begin(), DT.Roots.end(), HasForwardSuccessors))
+ if (std::none_of(DT.Roots.begin(), DT.Roots.end(), [BUI](const NodePtr N) {
+ return HasForwardSuccessors(N, BUI);
+ }))
return;
// Recalculate the set of roots.
- DT.Roots = FindRoots(DT);
+ DT.Roots = FindRoots(DT, BUI);
for (const NodePtr R : DT.Roots) {
const TreeNodePtr TN = DT.getNode(R);
// A CFG node was selected as a tree root, but the corresponding tree node
@@ -617,18 +713,18 @@ struct SemiNCAInfo {
// It should be possible to rotate the subtree instead of recalculating
// the whole tree, but this situation happens extremely rarely in
// practice.
- DT.recalculate(*DT.Parent);
+ CalculateFromScratch(DT, BUI);
return;
}
}
}
// Handles insertion to a node already in the dominator tree.
- static void InsertReachable(DomTreeT &DT, const TreeNodePtr From,
- const TreeNodePtr To) {
+ static void InsertReachable(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr From, const TreeNodePtr To) {
DEBUG(dbgs() << "\tReachable " << BlockNamePrinter(From->getBlock())
<< " -> " << BlockNamePrinter(To->getBlock()) << "\n");
- if (IsPostDom && UpdateRootsBeforeInsertion(DT, From, To)) return;
+ if (IsPostDom && UpdateRootsBeforeInsertion(DT, BUI, From, To)) return;
// DT.findNCD expects both pointers to be valid. When From is a virtual
// root, then its CFG block pointer is a nullptr, so we have to 'compute'
// the NCD manually.
@@ -664,17 +760,17 @@ struct SemiNCAInfo {
II.AffectedQueue.push_back(CurrentNode);
// Discover and collect affected successors of the current node.
- VisitInsertion(DT, CurrentNode, CurrentNode->getLevel(), NCD, II);
+ VisitInsertion(DT, BUI, CurrentNode, CurrentNode->getLevel(), NCD, II);
}
// Finish by updating immediate dominators and levels.
- UpdateInsertion(DT, NCD, II);
+ UpdateInsertion(DT, BUI, NCD, II);
}
// Visits an affected node and collect its affected successors.
- static void VisitInsertion(DomTreeT &DT, const TreeNodePtr TN,
- const unsigned RootLevel, const TreeNodePtr NCD,
- InsertionInfo &II) {
+ static void VisitInsertion(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr TN, const unsigned RootLevel,
+ const TreeNodePtr NCD, InsertionInfo &II) {
const unsigned NCDLevel = NCD->getLevel();
DEBUG(dbgs() << "Visiting " << BlockNamePrinter(TN) << "\n");
@@ -685,7 +781,7 @@ struct SemiNCAInfo {
TreeNodePtr Next = Stack.pop_back_val();
for (const NodePtr Succ :
- ChildrenGetter<NodePtr, IsPostDom>::Get(Next->getBlock())) {
+ ChildrenGetter<IsPostDom>::Get(Next->getBlock(), BUI)) {
const TreeNodePtr SuccTN = DT.getNode(Succ);
assert(SuccTN && "Unreachable successor found at reachable insertion");
const unsigned SuccLevel = SuccTN->getLevel();
@@ -706,7 +802,7 @@ struct SemiNCAInfo {
II.VisitedNotAffectedQueue.push_back(SuccTN);
Stack.push_back(SuccTN);
} else if ((SuccLevel > NCDLevel + 1) &&
- II.Affected.count(SuccTN) == 0) {
+ II.Affected.count(SuccTN) == 0) {
DEBUG(dbgs() << "\t\tMarking affected and adding "
<< BlockNamePrinter(Succ) << " to a Bucket\n");
II.Affected.insert(SuccTN);
@@ -717,8 +813,8 @@ struct SemiNCAInfo {
}
// Updates immediate dominators and levels after insertion.
- static void UpdateInsertion(DomTreeT &DT, const TreeNodePtr NCD,
- InsertionInfo &II) {
+ static void UpdateInsertion(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr NCD, InsertionInfo &II) {
DEBUG(dbgs() << "Updating NCD = " << BlockNamePrinter(NCD) << "\n");
for (const TreeNodePtr TN : II.AffectedQueue) {
@@ -728,7 +824,7 @@ struct SemiNCAInfo {
}
UpdateLevelsAfterInsertion(II);
- if (IsPostDom) UpdateRootsAfterUpdate(DT);
+ if (IsPostDom) UpdateRootsAfterUpdate(DT, BUI);
}
static void UpdateLevelsAfterInsertion(InsertionInfo &II) {
@@ -743,15 +839,15 @@ struct SemiNCAInfo {
}
// Handles insertion to previously unreachable nodes.
- static void InsertUnreachable(DomTreeT &DT, const TreeNodePtr From,
- const NodePtr To) {
+ static void InsertUnreachable(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr From, const NodePtr To) {
DEBUG(dbgs() << "Inserting " << BlockNamePrinter(From)
<< " -> (unreachable) " << BlockNamePrinter(To) << "\n");
// Collect discovered edges to already reachable nodes.
SmallVector<std::pair<NodePtr, TreeNodePtr>, 8> DiscoveredEdgesToReachable;
// Discover and connect nodes that became reachable with the insertion.
- ComputeUnreachableDominators(DT, To, From, DiscoveredEdgesToReachable);
+ ComputeUnreachableDominators(DT, BUI, To, From, DiscoveredEdgesToReachable);
DEBUG(dbgs() << "Inserted " << BlockNamePrinter(From)
<< " -> (prev unreachable) " << BlockNamePrinter(To) << "\n");
@@ -764,15 +860,16 @@ struct SemiNCAInfo {
DEBUG(dbgs() << "\tInserting discovered connecting edge "
<< BlockNamePrinter(Edge.first) << " -> "
<< BlockNamePrinter(Edge.second) << "\n");
- InsertReachable(DT, DT.getNode(Edge.first), Edge.second);
+ InsertReachable(DT, BUI, DT.getNode(Edge.first), Edge.second);
}
}
// Connects nodes that become reachable with an insertion.
static void ComputeUnreachableDominators(
- DomTreeT &DT, const NodePtr Root, const TreeNodePtr Incoming,
+ DomTreeT &DT, const BatchUpdatePtr BUI, const NodePtr Root,
+ const TreeNodePtr Incoming,
SmallVectorImpl<std::pair<NodePtr, TreeNodePtr>>
- &DiscoveredConnectingEdges) {
+ &DiscoveredConnectingEdges) {
assert(!DT.getNode(Root) && "Root must not be reachable");
// Visit only previously unreachable nodes.
@@ -785,7 +882,7 @@ struct SemiNCAInfo {
return false;
};
- SemiNCAInfo SNCA;
+ SemiNCAInfo SNCA(BUI);
SNCA.runDFS(Root, 0, UnreachableDescender, 0);
SNCA.runSemiNCA(DT);
SNCA.attachNewSubtree(DT, Incoming);
@@ -794,7 +891,8 @@ struct SemiNCAInfo {
DEBUG(DT.print(dbgs()));
}
- static void DeleteEdge(DomTreeT &DT, const NodePtr From, const NodePtr To) {
+ static void DeleteEdge(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const NodePtr From, const NodePtr To) {
assert(From && To && "Cannot disconnect nullptrs");
DEBUG(dbgs() << "Deleting edge " << BlockNamePrinter(From) << " -> "
<< BlockNamePrinter(To) << "\n");
@@ -803,8 +901,8 @@ struct SemiNCAInfo {
// Ensure that the edge was in fact deleted from the CFG before informing
// the DomTree about it.
// The check is O(N), so run it only in debug configuration.
- auto IsSuccessor = [](const NodePtr SuccCandidate, const NodePtr Of) {
- auto Successors = ChildrenGetter<NodePtr, IsPostDom>::Get(Of);
+ auto IsSuccessor = [BUI](const NodePtr SuccCandidate, const NodePtr Of) {
+ auto Successors = ChildrenGetter<IsPostDom>::Get(Of, BUI);
return llvm::find(Successors, SuccCandidate) != Successors.end();
};
(void)IsSuccessor;
@@ -829,16 +927,17 @@ struct SemiNCAInfo {
// To remains reachable after deletion.
// (Based on the caption under Figure 4. from the second paper.)
- if (FromTN != ToIDom || HasProperSupport(DT, ToTN))
- DeleteReachable(DT, FromTN, ToTN);
+ if (FromTN != ToIDom || HasProperSupport(DT, BUI, ToTN))
+ DeleteReachable(DT, BUI, FromTN, ToTN);
else
- DeleteUnreachable(DT, ToTN);
+ DeleteUnreachable(DT, BUI, ToTN);
- if (IsPostDom) UpdateRootsAfterUpdate(DT);
+ if (IsPostDom) UpdateRootsAfterUpdate(DT, BUI);
}
// Handles deletions that leave destination nodes reachable.
- static void DeleteReachable(DomTreeT &DT, const TreeNodePtr FromTN,
+ static void DeleteReachable(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr FromTN,
const TreeNodePtr ToTN) {
DEBUG(dbgs() << "Deleting reachable " << BlockNamePrinter(FromTN) << " -> "
<< BlockNamePrinter(ToTN) << "\n");
@@ -856,7 +955,7 @@ struct SemiNCAInfo {
// scratch.
if (!PrevIDomSubTree) {
DEBUG(dbgs() << "The entire tree needs to be rebuilt\n");
- DT.recalculate(*DT.Parent);
+ CalculateFromScratch(DT, BUI);
return;
}
@@ -868,7 +967,7 @@ struct SemiNCAInfo {
DEBUG(dbgs() << "\tTop of subtree: " << BlockNamePrinter(ToIDomTN) << "\n");
- SemiNCAInfo SNCA;
+ SemiNCAInfo SNCA(BUI);
SNCA.runDFS(ToIDom, 0, DescendBelow, 0);
DEBUG(dbgs() << "\tRunning Semi-NCA\n");
SNCA.runSemiNCA(DT, Level);
@@ -877,10 +976,11 @@ struct SemiNCAInfo {
// Checks if a node has proper support, as defined on the page 3 and later
// explained on the page 7 of the second paper.
- static bool HasProperSupport(DomTreeT &DT, const TreeNodePtr TN) {
+ static bool HasProperSupport(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr TN) {
DEBUG(dbgs() << "IsReachableFromIDom " << BlockNamePrinter(TN) << "\n");
for (const NodePtr Pred :
- ChildrenGetter<NodePtr, !IsPostDom>::Get(TN->getBlock())) {
+ ChildrenGetter<!IsPostDom>::Get(TN->getBlock(), BUI)) {
DEBUG(dbgs() << "\tPred " << BlockNamePrinter(Pred) << "\n");
if (!DT.getNode(Pred)) continue;
@@ -900,7 +1000,8 @@ struct SemiNCAInfo {
// Handle deletions that make destination node unreachable.
// (Based on the lemma 2.7 from the second paper.)
- static void DeleteUnreachable(DomTreeT &DT, const TreeNodePtr ToTN) {
+ static void DeleteUnreachable(DomTreeT &DT, const BatchUpdatePtr BUI,
+ const TreeNodePtr ToTN) {
DEBUG(dbgs() << "Deleting unreachable subtree " << BlockNamePrinter(ToTN)
<< "\n");
assert(ToTN);
@@ -913,7 +1014,7 @@ struct SemiNCAInfo {
DEBUG(dbgs() << "\tDeletion made a region reverse-unreachable\n");
DEBUG(dbgs() << "\tAdding new root " << BlockNamePrinter(ToTN) << "\n");
DT.Roots.push_back(ToTN->getBlock());
- InsertReachable(DT, DT.getNode(nullptr), ToTN);
+ InsertReachable(DT, BUI, DT.getNode(nullptr), ToTN);
return;
}
@@ -932,7 +1033,7 @@ struct SemiNCAInfo {
return false;
};
- SemiNCAInfo SNCA;
+ SemiNCAInfo SNCA(BUI);
unsigned LastDFSNum =
SNCA.runDFS(ToTN->getBlock(), 0, DescendAndCollect, 0);
@@ -957,7 +1058,7 @@ struct SemiNCAInfo {
// Root reached, rebuild the whole tree from scratch.
if (!MinNode->getIDom()) {
DEBUG(dbgs() << "The entire tree needs to be rebuilt\n");
- DT.recalculate(*DT.Parent);
+ CalculateFromScratch(DT, BUI);
return;
}
@@ -1013,6 +1114,126 @@ struct SemiNCAInfo {
}
//~~
+ //===--------------------- DomTree Batch Updater --------------------------===
+ //~~
+
+ static void ApplyUpdates(DomTreeT &DT, ArrayRef<UpdateT> Updates) {
+ BatchUpdateInfo BUI;
+ LegalizeUpdates(Updates, BUI.Updates);
+
+ const size_t NumLegalized = BUI.Updates.size();
+ BUI.FutureSuccessors.reserve(NumLegalized);
+ BUI.FuturePredecessors.reserve(NumLegalized);
+
+ // Use the legalized future updates to initialize future successors and
+ // predecessors. Note that these sets will only decrease size over time, as
+ // the next CFG snapshots slowly approach the actual (current) CFG.
+ for (UpdateT &U : BUI.Updates) {
+ BUI.FutureSuccessors[U.getFrom()].insert({U.getTo(), U.getKind()});
+ BUI.FuturePredecessors[U.getTo()].insert({U.getFrom(), U.getKind()});
+ }
+
+ DEBUG(dbgs() << "About to apply " << NumLegalized << " updates\n");
+ DEBUG(if (NumLegalized < 32) for (const auto &U
+ : reverse(BUI.Updates)) dbgs()
+ << '\t' << U << "\n");
+ DEBUG(dbgs() << "\n");
+
+ // If the DominatorTree was recalculated at some point, stop the batch
+ // updates. Full recalculations ignore batch updates and look at the actual
+ // CFG.
+ for (size_t i = 0; i < NumLegalized && !BUI.IsRecalculated; ++i)
+ ApplyNextUpdate(DT, BUI);
+ }
+
+ // This function serves double purpose:
+ // a) It removes redundant updates, which makes it easier to reverse-apply
+ // them when traversing CFG.
+ // b) It optimizes away updates that cancel each other out, as the end result
+ // is the same.
+ //
+ // It relies on the property of the incremental updates that says that the
+ // order of updates doesn't matter. This allows us to reorder them and end up
+ // with the exact same DomTree every time.
+ //
+ // Following the same logic, the function doesn't care about the order of
+ // input updates, so it's OK to pass it an unordered sequence of updates, that
+ // doesn't make sense when applied sequentially, eg. performing double
+ // insertions or deletions and then doing an opposite update.
+ //
+ // In the future, it should be possible to schedule updates in way that
+ // minimizes the amount of work needed done during incremental updates.
+ static void LegalizeUpdates(ArrayRef<UpdateT> AllUpdates,
+ SmallVectorImpl<UpdateT> &Result) {
+ DEBUG(dbgs() << "Legalizing " << AllUpdates.size() << " updates\n");
+ // Count the total number of inserions of each edge.
+ // Each insertion adds 1 and deletion subtracts 1. The end number should be
+ // one of {-1 (deletion), 0 (NOP), +1 (insertion)}. Otherwise, the sequence
+ // of updates contains multiple updates of the same kind and we assert for
+ // that case.
+ SmallDenseMap<std::pair<NodePtr, NodePtr>, int, 4> Operations;
+ Operations.reserve(AllUpdates.size());
+
+ for (const auto &U : AllUpdates) {
+ NodePtr From = U.getFrom();
+ NodePtr To = U.getTo();
+ if (IsPostDom) std::swap(From, To); // Reverse edge for postdominators.
+
+ Operations[{From, To}] += (U.getKind() == UpdateKind::Insert ? 1 : -1);
+ }
+
+ Result.clear();
+ Result.reserve(Operations.size());
+ for (auto &Op : Operations) {
+ const int NumInsertions = Op.second;
+ assert(std::abs(NumInsertions) <= 1 && "Unbalanced operations!");
+ if (NumInsertions == 0) continue;
+ const UpdateKind UK =
+ NumInsertions > 0 ? UpdateKind::Insert : UpdateKind::Delete;
+ Result.push_back({UK, Op.first.first, Op.first.second});
+ }
+
+ // Make the order consistent by not relying on pointer values within the
+ // set. Reuse the old Operations map.
+ // In the future, we should sort by something else to minimize the amount
+ // of work needed to perform the series of updates.
+ for (size_t i = 0, e = AllUpdates.size(); i != e; ++i) {
+ const auto &U = AllUpdates[i];
+ if (!IsPostDom)
+ Operations[{U.getFrom(), U.getTo()}] = int(i);
+ else
+ Operations[{U.getTo(), U.getFrom()}] = int(i);
+ }
+
+ std::sort(Result.begin(), Result.end(),
+ [&Operations](const UpdateT &A, const UpdateT &B) {
+ return Operations[{A.getFrom(), A.getTo()}] >
+ Operations[{B.getFrom(), B.getTo()}];
+ });
+ }
+
+ static void ApplyNextUpdate(DomTreeT &DT, BatchUpdateInfo &BUI) {
+ assert(!BUI.Updates.empty() && "No updates to apply!");
+ UpdateT CurrentUpdate = BUI.Updates.pop_back_val();
+ DEBUG(dbgs() << "Applying update: " << CurrentUpdate << "\n");
+
+ // Move to the next snapshot of the CFG by removing the reverse-applied
+ // current update.
+ auto &FS = BUI.FutureSuccessors[CurrentUpdate.getFrom()];
+ FS.erase({CurrentUpdate.getTo(), CurrentUpdate.getKind()});
+ if (FS.empty()) BUI.FutureSuccessors.erase(CurrentUpdate.getFrom());
+
+ auto &FP = BUI.FuturePredecessors[CurrentUpdate.getTo()];
+ FP.erase({CurrentUpdate.getFrom(), CurrentUpdate.getKind()});
+ if (FP.empty()) BUI.FuturePredecessors.erase(CurrentUpdate.getTo());
+
+ if (CurrentUpdate.getKind() == UpdateKind::Insert)
+ InsertEdge(DT, &BUI, CurrentUpdate.getFrom(), CurrentUpdate.getTo());
+ else
+ DeleteEdge(DT, &BUI, CurrentUpdate.getFrom(), CurrentUpdate.getTo());
+ }
+
+ //~~
//===--------------- DomTree correctness verification ---------------------===
//~~
@@ -1041,7 +1262,7 @@ struct SemiNCAInfo {
}
}
- RootsT ComputedRoots = FindRoots(DT);
+ RootsT ComputedRoots = FindRoots(DT, nullptr);
if (DT.Roots.size() != ComputedRoots.size() ||
!std::is_permutation(DT.Roots.begin(), DT.Roots.end(),
ComputedRoots.begin())) {
@@ -1268,27 +1489,32 @@ struct SemiNCAInfo {
template <class DomTreeT>
void Calculate(DomTreeT &DT) {
- SemiNCAInfo<DomTreeT> SNCA;
- SNCA.calculateFromScratch(DT);
+ SemiNCAInfo<DomTreeT>::CalculateFromScratch(DT, nullptr);
}
template <class DomTreeT>
void InsertEdge(DomTreeT &DT, typename DomTreeT::NodePtr From,
typename DomTreeT::NodePtr To) {
if (DT.isPostDominator()) std::swap(From, To);
- SemiNCAInfo<DomTreeT>::InsertEdge(DT, From, To);
+ SemiNCAInfo<DomTreeT>::InsertEdge(DT, nullptr, From, To);
}
template <class DomTreeT>
void DeleteEdge(DomTreeT &DT, typename DomTreeT::NodePtr From,
typename DomTreeT::NodePtr To) {
if (DT.isPostDominator()) std::swap(From, To);
- SemiNCAInfo<DomTreeT>::DeleteEdge(DT, From, To);
+ SemiNCAInfo<DomTreeT>::DeleteEdge(DT, nullptr, From, To);
+}
+
+template <class DomTreeT>
+void ApplyUpdates(DomTreeT &DT,
+ ArrayRef<typename DomTreeT::UpdateType> Updates) {
+ SemiNCAInfo<DomTreeT>::ApplyUpdates(DT, Updates);
}
template <class DomTreeT>
bool Verify(const DomTreeT &DT) {
- SemiNCAInfo<DomTreeT> SNCA;
+ SemiNCAInfo<DomTreeT> SNCA(nullptr);
return SNCA.verifyRoots(DT) && SNCA.verifyReachability(DT) &&
SNCA.VerifyLevels(DT) && SNCA.verifyNCD(DT) &&
SNCA.verifyParentProperty(DT) && SNCA.verifySiblingProperty(DT);
Modified: llvm/trunk/lib/IR/Dominators.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Dominators.cpp?rev=311015&r1=311014&r2=311015&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Dominators.cpp (original)
+++ llvm/trunk/lib/IR/Dominators.cpp Wed Aug 16 09:12:52 2017
@@ -64,6 +64,8 @@ template class llvm::DomTreeNodeBase<Bas
template class llvm::DominatorTreeBase<BasicBlock, false>; // DomTreeBase
template class llvm::DominatorTreeBase<BasicBlock, true>; // PostDomTreeBase
+template struct llvm::DomTreeBuilder::Update<BasicBlock *>;
+
template void llvm::DomTreeBuilder::Calculate<DomTreeBuilder::BBDomTree>(
DomTreeBuilder::BBDomTree &DT);
template void llvm::DomTreeBuilder::Calculate<DomTreeBuilder::BBPostDomTree>(
@@ -79,6 +81,11 @@ template void llvm::DomTreeBuilder::Dele
template void llvm::DomTreeBuilder::DeleteEdge<DomTreeBuilder::BBPostDomTree>(
DomTreeBuilder::BBPostDomTree &DT, BasicBlock *From, BasicBlock *To);
+template void llvm::DomTreeBuilder::ApplyUpdates<DomTreeBuilder::BBDomTree>(
+ DomTreeBuilder::BBDomTree &DT, DomTreeBuilder::BBUpdates);
+template void llvm::DomTreeBuilder::ApplyUpdates<DomTreeBuilder::BBPostDomTree>(
+ DomTreeBuilder::BBPostDomTree &DT, DomTreeBuilder::BBUpdates);
+
template bool llvm::DomTreeBuilder::Verify<DomTreeBuilder::BBDomTree>(
const DomTreeBuilder::BBDomTree &DT);
template bool llvm::DomTreeBuilder::Verify<DomTreeBuilder::BBPostDomTree>(
@@ -312,6 +319,9 @@ void DominatorTree::verifyDomTree() cons
print(errs());
errs() << "\nActual:\n";
OtherDT.print(errs());
+ errs() << "\nCFG:\n";
+ F.print(errs());
+ errs().flush();
abort();
}
}
Modified: llvm/trunk/unittests/IR/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/CMakeLists.txt?rev=311015&r1=311014&r2=311015&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/CMakeLists.txt (original)
+++ llvm/trunk/unittests/IR/CMakeLists.txt Wed Aug 16 09:12:52 2017
@@ -16,6 +16,7 @@ set(IRSources
DebugInfoTest.cpp
DebugTypeODRUniquingTest.cpp
DominatorTreeTest.cpp
+ DominatorTreeBatchUpdatesTest.cpp
FunctionTest.cpp
PassBuilderCallbacksTest.cpp
IRBuilderTest.cpp
Added: llvm/trunk/unittests/IR/DominatorTreeBatchUpdatesTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/DominatorTreeBatchUpdatesTest.cpp?rev=311015&view=auto
==============================================================================
--- llvm/trunk/unittests/IR/DominatorTreeBatchUpdatesTest.cpp (added)
+++ llvm/trunk/unittests/IR/DominatorTreeBatchUpdatesTest.cpp Wed Aug 16 09:12:52 2017
@@ -0,0 +1,260 @@
+//===- llvm/unittests/IR/DominatorTreeBatchUpdatesTest.cpp ----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <random>
+#include "CFGBuilder.h"
+#include "gtest/gtest.h"
+#include "llvm/Analysis/PostDominators.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/Support/GenericDomTreeConstruction.h"
+
+#define DEBUG_TYPE "batch-update-tests"
+
+using namespace llvm;
+
+namespace {
+const auto CFGInsert = CFGBuilder::ActionKind::Insert;
+const auto CFGDelete = CFGBuilder::ActionKind::Delete;
+
+struct PostDomTree : PostDomTreeBase<BasicBlock> {
+ PostDomTree(Function &F) { recalculate(F); }
+};
+
+using DomUpdate = DominatorTree::UpdateType;
+static_assert(
+ std::is_same<DomUpdate, PostDomTree::UpdateType>::value,
+ "Trees differing only in IsPostDom should have the same update types");
+using DomSNCA = DomTreeBuilder::SemiNCAInfo<DomTreeBuilder::BBDomTree>;
+using PostDomSNCA = DomTreeBuilder::SemiNCAInfo<DomTreeBuilder::BBPostDomTree>;
+const auto Insert = DominatorTree::Insert;
+const auto Delete = DominatorTree::Delete;
+
+std::vector<DomUpdate> ToDomUpdates(CFGBuilder &B,
+ std::vector<CFGBuilder::Update> &In) {
+ std::vector<DomUpdate> Res;
+ Res.reserve(In.size());
+
+ for (const auto &CFGU : In)
+ Res.push_back({CFGU.Action == CFGInsert ? Insert : Delete,
+ B.getOrAddBlock(CFGU.Edge.From),
+ B.getOrAddBlock(CFGU.Edge.To)});
+ return Res;
+}
+} // namespace
+
+TEST(DominatorTreeBatchUpdates, LegalizeDomUpdates) {
+ CFGHolder Holder;
+ CFGBuilder Builder(Holder.F, {{"A", "B"}}, {});
+
+ BasicBlock *A = Builder.getOrAddBlock("A");
+ BasicBlock *B = Builder.getOrAddBlock("B");
+ BasicBlock *C = Builder.getOrAddBlock("C");
+ BasicBlock *D = Builder.getOrAddBlock("D");
+
+ std::vector<DomUpdate> Updates = {
+ {Insert, B, C}, {Insert, C, D}, {Delete, B, C}, {Insert, B, C},
+ {Insert, B, D}, {Delete, C, D}, {Delete, A, B}};
+ SmallVector<DomUpdate, 4> Legalized;
+ DomSNCA::LegalizeUpdates(Updates, Legalized);
+ DEBUG(dbgs() << "Legalized updates:\t");
+ DEBUG(for (auto &U : Legalized) dbgs() << U << ", ");
+ DEBUG(dbgs() << "\n");
+ EXPECT_EQ(Legalized.size(), 3UL);
+ EXPECT_NE(llvm::find(Legalized, DomUpdate{Insert, B, C}), Legalized.end());
+ EXPECT_NE(llvm::find(Legalized, DomUpdate{Insert, B, D}), Legalized.end());
+ EXPECT_NE(llvm::find(Legalized, DomUpdate{Delete, A, B}), Legalized.end());
+}
+
+TEST(DominatorTreeBatchUpdates, LegalizePostDomUpdates) {
+ CFGHolder Holder;
+ CFGBuilder Builder(Holder.F, {{"A", "B"}}, {});
+
+ BasicBlock *A = Builder.getOrAddBlock("A");
+ BasicBlock *B = Builder.getOrAddBlock("B");
+ BasicBlock *C = Builder.getOrAddBlock("C");
+ BasicBlock *D = Builder.getOrAddBlock("D");
+
+ std::vector<DomUpdate> Updates = {
+ {Insert, B, C}, {Insert, C, D}, {Delete, B, C}, {Insert, B, C},
+ {Insert, B, D}, {Delete, C, D}, {Delete, A, B}};
+ SmallVector<DomUpdate, 4> Legalized;
+ PostDomSNCA::LegalizeUpdates(Updates, Legalized);
+ DEBUG(dbgs() << "Legalized postdom updates:\t");
+ DEBUG(for (auto &U : Legalized) dbgs() << U << ", ");
+ DEBUG(dbgs() << "\n");
+ EXPECT_EQ(Legalized.size(), 3UL);
+ EXPECT_NE(llvm::find(Legalized, DomUpdate{Insert, C, B}), Legalized.end());
+ EXPECT_NE(llvm::find(Legalized, DomUpdate{Insert, D, B}), Legalized.end());
+ EXPECT_NE(llvm::find(Legalized, DomUpdate{Delete, B, A}), Legalized.end());
+}
+
+TEST(DominatorTreeBatchUpdates, SingleInsertion) {
+ CFGHolder Holder;
+ CFGBuilder Builder(Holder.F, {{"A", "B"}}, {{CFGInsert, {"B", "C"}}});
+
+ DominatorTree DT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+ PostDomTree PDT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+
+ BasicBlock *B = Builder.getOrAddBlock("B");
+ BasicBlock *C = Builder.getOrAddBlock("C");
+ std::vector<DomUpdate> Updates = {{Insert, B, C}};
+
+ ASSERT_TRUE(Builder.applyUpdate());
+
+ DT.applyUpdates(Updates);
+ EXPECT_TRUE(DT.verify());
+ PDT.applyUpdates(Updates);
+ EXPECT_TRUE(PDT.verify());
+}
+
+TEST(DominatorTreeBatchUpdates, SingleDeletion) {
+ CFGHolder Holder;
+ CFGBuilder Builder(Holder.F, {{"A", "B"}, {"B", "C"}},
+ {{CFGDelete, {"B", "C"}}});
+
+ DominatorTree DT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+ PostDomTree PDT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+
+ BasicBlock *B = Builder.getOrAddBlock("B");
+ BasicBlock *C = Builder.getOrAddBlock("C");
+ std::vector<DomUpdate> Updates = {{Delete, B, C}};
+
+ ASSERT_TRUE(Builder.applyUpdate());
+
+ DT.applyUpdates(Updates);
+ EXPECT_TRUE(DT.verify());
+ PDT.applyUpdates(Updates);
+ EXPECT_TRUE(PDT.verify());
+}
+
+TEST(DominatorTreeBatchUpdates, FewInsertion) {
+ std::vector<CFGBuilder::Update> CFGUpdates = {{CFGInsert, {"B", "C"}},
+ {CFGInsert, {"C", "B"}},
+ {CFGInsert, {"C", "D"}},
+ {CFGInsert, {"D", "E"}}};
+
+ CFGHolder Holder;
+ CFGBuilder Builder(Holder.F, {{"A", "B"}}, CFGUpdates);
+
+ DominatorTree DT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+ PostDomTree PDT(*Holder.F);
+ EXPECT_TRUE(PDT.verify());
+
+ BasicBlock *B = Builder.getOrAddBlock("B");
+ BasicBlock *C = Builder.getOrAddBlock("C");
+ BasicBlock *D = Builder.getOrAddBlock("D");
+ BasicBlock *E = Builder.getOrAddBlock("E");
+
+ std::vector<DomUpdate> Updates = {
+ {Insert, B, C}, {Insert, C, B}, {Insert, C, D}, {Insert, D, E}};
+
+ while (Builder.applyUpdate())
+ ;
+
+ DT.applyUpdates(Updates);
+ EXPECT_TRUE(DT.verify());
+ PDT.applyUpdates(Updates);
+ EXPECT_TRUE(PDT.verify());
+}
+
+TEST(DominatorTreeBatchUpdates, FewDeletions) {
+ std::vector<CFGBuilder::Update> CFGUpdates = {{CFGDelete, {"B", "C"}},
+ {CFGDelete, {"C", "B"}},
+ {CFGDelete, {"B", "D"}},
+ {CFGDelete, {"D", "E"}}};
+
+ CFGHolder Holder;
+ CFGBuilder Builder(
+ Holder.F, {{"A", "B"}, {"B", "C"}, {"B", "D"}, {"D", "E"}, {"C", "B"}},
+ CFGUpdates);
+
+ DominatorTree DT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+ PostDomTree PDT(*Holder.F);
+ EXPECT_TRUE(PDT.verify());
+
+ auto Updates = ToDomUpdates(Builder, CFGUpdates);
+
+ while (Builder.applyUpdate())
+ ;
+
+ DT.applyUpdates(Updates);
+ EXPECT_TRUE(DT.verify());
+ PDT.applyUpdates(Updates);
+ EXPECT_TRUE(PDT.verify());
+}
+
+TEST(DominatorTreeBatchUpdates, InsertDelete) {
+ std::vector<CFGBuilder::Arc> Arcs = {
+ {"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
+ {"3", "8"}, {"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}};
+
+ std::vector<CFGBuilder::Update> Updates = {
+ {CFGInsert, {"2", "4"}}, {CFGInsert, {"12", "10"}},
+ {CFGInsert, {"10", "9"}}, {CFGInsert, {"7", "6"}},
+ {CFGInsert, {"7", "5"}}, {CFGDelete, {"3", "8"}},
+ {CFGInsert, {"10", "7"}}, {CFGInsert, {"2", "8"}},
+ {CFGDelete, {"3", "4"}}, {CFGDelete, {"8", "9"}},
+ {CFGDelete, {"11", "12"}}};
+
+ CFGHolder Holder;
+ CFGBuilder B(Holder.F, Arcs, Updates);
+ DominatorTree DT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+ PostDomTree PDT(*Holder.F);
+ EXPECT_TRUE(PDT.verify());
+
+ while (B.applyUpdate())
+ ;
+
+ auto DomUpdates = ToDomUpdates(B, Updates);
+ DT.applyUpdates(DomUpdates);
+ EXPECT_TRUE(DT.verify());
+ PDT.applyUpdates(DomUpdates);
+ EXPECT_TRUE(PDT.verify());
+}
+
+TEST(DominatorTreeBatchUpdates, InsertDeleteExhaustive) {
+ std::vector<CFGBuilder::Arc> Arcs = {
+ {"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
+ {"3", "8"}, {"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}};
+
+ std::vector<CFGBuilder::Update> Updates = {
+ {CFGInsert, {"2", "4"}}, {CFGInsert, {"12", "10"}},
+ {CFGInsert, {"10", "9"}}, {CFGInsert, {"7", "6"}},
+ {CFGInsert, {"7", "5"}}, {CFGDelete, {"3", "8"}},
+ {CFGInsert, {"10", "7"}}, {CFGInsert, {"2", "8"}},
+ {CFGDelete, {"3", "4"}}, {CFGDelete, {"8", "9"}},
+ {CFGDelete, {"11", "12"}}};
+
+ std::mt19937 Generator(0);
+ for (unsigned i = 0; i < 16; ++i) {
+ std::shuffle(Updates.begin(), Updates.end(), Generator);
+ CFGHolder Holder;
+ CFGBuilder B(Holder.F, Arcs, Updates);
+ DominatorTree DT(*Holder.F);
+ EXPECT_TRUE(DT.verify());
+ PostDomTree PDT(*Holder.F);
+ EXPECT_TRUE(PDT.verify());
+
+ while (B.applyUpdate())
+ ;
+
+ auto DomUpdates = ToDomUpdates(B, Updates);
+ DT.applyUpdates(DomUpdates);
+ EXPECT_TRUE(DT.verify());
+ PDT.applyUpdates(DomUpdates);
+ EXPECT_TRUE(PDT.verify());
+ }
+}
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