diff options
| -rw-r--r-- | llvm/include/llvm/ADT/PostOrderIterator.h | 27 |
1 files changed, 12 insertions, 15 deletions
diff --git a/llvm/include/llvm/ADT/PostOrderIterator.h b/llvm/include/llvm/ADT/PostOrderIterator.h index abc510714f34..a80eed78c94d 100644 --- a/llvm/include/llvm/ADT/PostOrderIterator.h +++ b/llvm/include/llvm/ADT/PostOrderIterator.h @@ -106,14 +106,13 @@ private: using NodeRef = typename GT::NodeRef; using ChildItTy = typename GT::ChildIteratorType; - /// Used to maintain the ordering. - /// First element is basic block pointer, second is iterator for the next - /// child to visit, third is the end iterator. - SmallVector<std::tuple<NodeRef, ChildItTy, ChildItTy>, 8> VisitStack; + // VisitStack - Used to maintain the ordering. Top = current block + // First element is basic block pointer, second is the 'next child' to visit + SmallVector<std::pair<NodeRef, ChildItTy>, 8> VisitStack; po_iterator(NodeRef BB) { this->insertEdge(std::optional<NodeRef>(), BB); - VisitStack.emplace_back(BB, GT::child_begin(BB), GT::child_end(BB)); + VisitStack.push_back(std::make_pair(BB, GT::child_begin(BB))); traverseChild(); } @@ -122,7 +121,7 @@ private: po_iterator(NodeRef BB, SetType &S) : po_iterator_storage<SetType, ExtStorage>(S) { if (this->insertEdge(std::optional<NodeRef>(), BB)) { - VisitStack.emplace_back(BB, GT::child_begin(BB), GT::child_end(BB)); + VisitStack.push_back(std::make_pair(BB, GT::child_begin(BB))); traverseChild(); } } @@ -132,14 +131,12 @@ private: } // End is when stack is empty. void traverseChild() { - while (true) { - auto &[ParentBB, It, End] = VisitStack.back(); - if (It == End) - break; - NodeRef BB = *It++; - if (this->insertEdge(std::optional<NodeRef>(ParentBB), BB)) { + while (VisitStack.back().second != GT::child_end(VisitStack.back().first)) { + NodeRef BB = *VisitStack.back().second++; + if (this->insertEdge(std::optional<NodeRef>(VisitStack.back().first), + BB)) { // If the block is not visited... - VisitStack.emplace_back(BB, GT::child_begin(BB), GT::child_end(BB)); + VisitStack.push_back(std::make_pair(BB, GT::child_begin(BB))); } } } @@ -161,7 +158,7 @@ public: } bool operator!=(const po_iterator &x) const { return !(*this == x); } - const NodeRef &operator*() const { return std::get<0>(VisitStack.back()); } + const NodeRef &operator*() const { return VisitStack.back().first; } // This is a nonstandard operator-> that dereferences the pointer an extra // time... so that you can actually call methods ON the BasicBlock, because @@ -170,7 +167,7 @@ public: NodeRef operator->() const { return **this; } po_iterator &operator++() { // Preincrement - this->finishPostorder(std::get<0>(VisitStack.back())); + this->finishPostorder(VisitStack.back().first); VisitStack.pop_back(); if (!VisitStack.empty()) traverseChild(); |