691a130e0f
Currently, po_iterator holds the traversal state. This makes copying and moving po_iterator fairly expensive and the code cannot be optimized away in several cases (most of it isn't even inlined in a default build). Therefore, refactor post-order traversal to hold the state in a wrapper class with cheap iterators. Additionally, replace po_storage base class with a CRTP implementation where users can provide their own storage. Benefits: - Performance in stage2-O3 improves by 0.19% instructions:u and even more substantially in cycles/wall-time. - Users that use a custom storage/iteration limitation can do so in a more clean way by subclassing PostIteratorTraversalBase. See e.g. LoopBlocksTraversal. - For graphs with block numbers, reserving can now be implemented reasonably easy (not done yet). Implications: - PostOrderTraversal::iterator is no longer a forward iterator. This property was never really used, though. - PostOrderTraversal must be live while iterators are live. For typical uses (for (X x : post_order(...))), this is no problem, but could end up being problematic if the iterator is wrapped (e.g. for (X x : make_filter_range(post_order(...), ...)) -- problematic, because make_filter_range doesn't preserve the range but only the two iterators, which become invalid as the for loop is entered). This is a limitation of the way LLVM implements ranges.
79 lines
2.2 KiB
C++
79 lines
2.2 KiB
C++
//===- PostOrderIteratorTest.cpp - PostOrderIterator unit tests -----------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
#include "llvm/ADT/PostOrderIterator.h"
|
|
#include "llvm/IR/BasicBlock.h"
|
|
#include "llvm/IR/CFG.h"
|
|
#include "gtest/gtest.h"
|
|
#include "TestGraph.h"
|
|
|
|
#include <array>
|
|
#include <iterator>
|
|
#include <type_traits>
|
|
|
|
#include <cstddef>
|
|
|
|
using namespace llvm;
|
|
|
|
namespace {
|
|
|
|
// Whether we're able to compile
|
|
TEST(PostOrderIteratorTest, Compiles) {
|
|
Graph<6> G;
|
|
using NodeType = Graph<6>::NodeType;
|
|
NodeType *NullNode = nullptr;
|
|
|
|
auto PI = post_order(G);
|
|
PI.insertEdge(std::optional<NodeType *>(), NullNode);
|
|
|
|
using ExtSetTy = SmallPtrSet<void *, 4>;
|
|
ExtSetTy Ext;
|
|
auto PIExt = post_order_ext(G, Ext);
|
|
PIExt.insertEdge(std::optional<NodeType *>(), NullNode);
|
|
}
|
|
|
|
static_assert(std::is_convertible_v<
|
|
decltype(*post_order(std::declval<Graph<3>>()).begin()),
|
|
PostOrderTraversal<Graph<3>>::iterator::reference>);
|
|
|
|
// Test post-order and reverse post-order traversals for simple graph type.
|
|
TEST(PostOrderIteratorTest, PostOrderAndReversePostOrderTraverrsal) {
|
|
Graph<6> G;
|
|
G.AddEdge(0, 1);
|
|
G.AddEdge(0, 2);
|
|
G.AddEdge(0, 3);
|
|
G.AddEdge(1, 4);
|
|
G.AddEdge(2, 5);
|
|
G.AddEdge(5, 2);
|
|
G.AddEdge(2, 4);
|
|
G.AddEdge(1, 4);
|
|
|
|
SmallVector<int> FromIterator;
|
|
for (auto N : post_order(G))
|
|
FromIterator.push_back(N->first);
|
|
EXPECT_EQ(6u, FromIterator.size());
|
|
EXPECT_EQ(4, FromIterator[0]);
|
|
EXPECT_EQ(1, FromIterator[1]);
|
|
EXPECT_EQ(5, FromIterator[2]);
|
|
EXPECT_EQ(2, FromIterator[3]);
|
|
EXPECT_EQ(3, FromIterator[4]);
|
|
EXPECT_EQ(0, FromIterator[5]);
|
|
FromIterator.clear();
|
|
|
|
ReversePostOrderTraversal<Graph<6>> RPOT(G);
|
|
for (auto N : RPOT)
|
|
FromIterator.push_back(N->first);
|
|
EXPECT_EQ(6u, FromIterator.size());
|
|
EXPECT_EQ(0, FromIterator[0]);
|
|
EXPECT_EQ(3, FromIterator[1]);
|
|
EXPECT_EQ(2, FromIterator[2]);
|
|
EXPECT_EQ(5, FromIterator[3]);
|
|
EXPECT_EQ(1, FromIterator[4]);
|
|
EXPECT_EQ(4, FromIterator[5]);
|
|
}
|
|
}
|