asbirlea created this revision.
asbirlea added reviewers: kuhar, dblaikie.
Herald added projects: clang, LLVM.
Herald added a subscriber: cfe-commits.
Simplify ChildrenGetter to a simple wrapper around a GraphDiff call.
GraphDiff already handles nullptr in children, so the special casing in
clang can also be removed.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D84713
Files:
clang/include/clang/Analysis/Analyses/Dominators.h
llvm/include/llvm/Support/GenericDomTreeConstruction.h
Index: llvm/include/llvm/Support/GenericDomTreeConstruction.h
===================================================================
--- llvm/include/llvm/Support/GenericDomTreeConstruction.h
+++ llvm/include/llvm/Support/GenericDomTreeConstruction.h
@@ -103,31 +103,13 @@
// in progress, we need this information to continue it.
}
- template <bool Inversed> 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, Inversed>;
-
- // 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) {
- if (!BUI)
- return Get(N, Tag());
+ template <bool Inversed>
+ static SmallVector<NodePtr, 8> ChildrenGet(NodePtr N, BatchUpdatePtr BUI) {
+ if (BUI)
return BUI->PreViewCFG.template getChildren<Inversed>(N);
- }
- };
+ GraphDiffT GD;
+ return GD.template getChildren<Inversed>(N);
+ }
NodePtr getIDom(NodePtr BB) const {
auto InfoIt = NodeToInfo.find(BB);
@@ -194,8 +176,7 @@
NumToNode.push_back(BB);
constexpr bool Direction = IsReverse != IsPostDom; // XOR.
- for (const NodePtr Succ :
- ChildrenGetter<Direction>::Get(BB, BatchUpdates)) {
+ for (const NodePtr Succ : ChildrenGet<Direction>(BB, BatchUpdates)) {
const auto SIT = NodeToInfo.find(Succ);
// Don't visit nodes more than once but remember to collect
// ReverseChildren.
@@ -330,7 +311,7 @@
// to CFG nodes within infinite loops.
static bool HasForwardSuccessors(const NodePtr N, BatchUpdatePtr BUI) {
assert(N && "N must be a valid node");
- return !ChildrenGetter<false>::Get(N, BUI).empty();
+ return !ChildrenGet<false>(N, BUI).empty();
}
static NodePtr GetEntryNode(const DomTreeT &DT) {
@@ -748,8 +729,7 @@
//
// Invariant: there is an optimal path from `To` to TN with the minimum
// depth being CurrentLevel.
- for (const NodePtr Succ :
- ChildrenGetter<IsPostDom>::Get(TN->getBlock(), BUI)) {
+ for (const NodePtr Succ : ChildrenGet<IsPostDom>(TN->getBlock(), BUI)) {
const TreeNodePtr SuccTN = DT.getNode(Succ);
assert(SuccTN &&
"Unreachable successor found at reachable insertion");
@@ -879,7 +859,7 @@
// the DomTree about it.
// The check is O(N), so run it only in debug configuration.
auto IsSuccessor = [BUI](const NodePtr SuccCandidate, const NodePtr Of) {
- auto Successors = ChildrenGetter<IsPostDom>::Get(Of, BUI);
+ auto Successors = ChildrenGet<IsPostDom>(Of, BUI);
return llvm::find(Successors, SuccCandidate) != Successors.end();
};
(void)IsSuccessor;
@@ -967,7 +947,7 @@
LLVM_DEBUG(dbgs() << "IsReachableFromIDom " << BlockNamePrinter(TN)
<< "\n");
auto TNB = TN->getBlock();
- for (const NodePtr Pred : ChildrenGetter<!IsPostDom>::Get(TNB, BUI)) {
+ for (const NodePtr Pred : ChildrenGet<!IsPostDom>(TNB, BUI)) {
LLVM_DEBUG(dbgs() << "\tPred " << BlockNamePrinter(Pred) << "\n");
if (!DT.getNode(Pred)) continue;
Index: clang/include/clang/Analysis/Analyses/Dominators.h
===================================================================
--- clang/include/clang/Analysis/Analyses/Dominators.h
+++ clang/include/clang/Analysis/Analyses/Dominators.h
@@ -273,76 +273,6 @@
namespace llvm {
-/// Clang's CFG contains nullpointers for unreachable succesors, e.g. when an
-/// if statement's condition is always false, it's 'then' branch is represented
-/// with a nullptr. This however will result in a nullpointer derefernece for
-/// dominator tree calculation.
-///
-/// To circumvent this, let's just crudely specialize the children getters
-/// used in LLVM's dominator tree builder.
-namespace DomTreeBuilder {
-
-using ClangCFGDomChildrenGetter =
-SemiNCAInfo<clang::CFGDomTree::DominatorTreeBase>::ChildrenGetter<
- /*Inverse=*/false>;
-
-template <>
-template <>
-inline ClangCFGDomChildrenGetter::ResultTy ClangCFGDomChildrenGetter::Get(
- clang::CFGBlock *N, std::integral_constant<bool, /*Inverse=*/false>) {
- auto RChildren = reverse(children<NodePtr>(N));
- ResultTy Ret(RChildren.begin(), RChildren.end());
- Ret.erase(std::remove(Ret.begin(), Ret.end(), nullptr), Ret.end());
- return Ret;
-}
-
-using ClangCFGDomReverseChildrenGetter =
-SemiNCAInfo<clang::CFGDomTree::DominatorTreeBase>::ChildrenGetter<
- /*Inverse=*/true>;
-
-template <>
-template <>
-inline ClangCFGDomReverseChildrenGetter::ResultTy
-ClangCFGDomReverseChildrenGetter::Get(
- clang::CFGBlock *N, std::integral_constant<bool, /*Inverse=*/true>) {
- auto IChildren = inverse_children<NodePtr>(N);
- ResultTy Ret(IChildren.begin(), IChildren.end());
- Ret.erase(std::remove(Ret.begin(), Ret.end(), nullptr), Ret.end());
- return Ret;
-}
-
-using ClangCFGPostDomChildrenGetter =
-SemiNCAInfo<clang::CFGPostDomTree::DominatorTreeBase>::ChildrenGetter<
- /*Inverse=*/false>;
-
-template <>
-template <>
-inline ClangCFGPostDomChildrenGetter::ResultTy
-ClangCFGPostDomChildrenGetter::Get(
- clang::CFGBlock *N, std::integral_constant<bool, /*Inverse=*/false>) {
- auto RChildren = reverse(children<NodePtr>(N));
- ResultTy Ret(RChildren.begin(), RChildren.end());
- Ret.erase(std::remove(Ret.begin(), Ret.end(), nullptr), Ret.end());
- return Ret;
-}
-
-using ClangCFGPostDomReverseChildrenGetter =
-SemiNCAInfo<clang::CFGPostDomTree::DominatorTreeBase>::ChildrenGetter<
- /*Inverse=*/true>;
-
-template <>
-template <>
-inline ClangCFGPostDomReverseChildrenGetter::ResultTy
-ClangCFGPostDomReverseChildrenGetter::Get(
- clang::CFGBlock *N, std::integral_constant<bool, /*Inverse=*/true>) {
- auto IChildren = inverse_children<NodePtr>(N);
- ResultTy Ret(IChildren.begin(), IChildren.end());
- Ret.erase(std::remove(Ret.begin(), Ret.end(), nullptr), Ret.end());
- return Ret;
-}
-
-} // end of namespace DomTreeBuilder
-
//===-------------------------------------
/// DominatorTree GraphTraits specialization so the DominatorTree can be
/// iterable by generic graph iterators.
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