mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-19 11:02:59 +02:00
ae65e281f3
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
121 lines
4.5 KiB
C++
121 lines
4.5 KiB
C++
//===----- llvm/unittest/ADT/SCCIteratorTest.cpp - SCCIterator 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/SCCIterator.h"
|
|
#include "TestGraph.h"
|
|
#include "gtest/gtest.h"
|
|
#include <limits.h>
|
|
|
|
using namespace llvm;
|
|
|
|
namespace llvm {
|
|
|
|
TEST(SCCIteratorTest, AllSmallGraphs) {
|
|
// Test SCC computation against every graph with NUM_NODES nodes or less.
|
|
// Since SCC considers every node to have an implicit self-edge, we only
|
|
// create graphs for which every node has a self-edge.
|
|
#define NUM_NODES 4
|
|
#define NUM_GRAPHS (NUM_NODES * (NUM_NODES - 1))
|
|
typedef Graph<NUM_NODES> GT;
|
|
|
|
/// Enumerate all graphs using NUM_GRAPHS bits.
|
|
static_assert(NUM_GRAPHS < sizeof(unsigned) * CHAR_BIT, "Too many graphs!");
|
|
for (unsigned GraphDescriptor = 0; GraphDescriptor < (1U << NUM_GRAPHS);
|
|
++GraphDescriptor) {
|
|
GT G;
|
|
|
|
// Add edges as specified by the descriptor.
|
|
unsigned DescriptorCopy = GraphDescriptor;
|
|
for (unsigned i = 0; i != NUM_NODES; ++i)
|
|
for (unsigned j = 0; j != NUM_NODES; ++j) {
|
|
// Always add a self-edge.
|
|
if (i == j) {
|
|
G.AddEdge(i, j);
|
|
continue;
|
|
}
|
|
if (DescriptorCopy & 1)
|
|
G.AddEdge(i, j);
|
|
DescriptorCopy >>= 1;
|
|
}
|
|
|
|
// Test the SCC logic on this graph.
|
|
|
|
/// NodesInSomeSCC - Those nodes which are in some SCC.
|
|
GT::NodeSubset NodesInSomeSCC;
|
|
|
|
for (scc_iterator<GT> I = scc_begin(G), E = scc_end(G); I != E; ++I) {
|
|
const std::vector<GT::NodeType *> &SCC = *I;
|
|
|
|
// Get the nodes in this SCC as a NodeSubset rather than a vector.
|
|
GT::NodeSubset NodesInThisSCC;
|
|
for (unsigned i = 0, e = SCC.size(); i != e; ++i)
|
|
NodesInThisSCC.AddNode(SCC[i]->first);
|
|
|
|
// There should be at least one node in every SCC.
|
|
EXPECT_FALSE(NodesInThisSCC.isEmpty());
|
|
|
|
// Check that every node in the SCC is reachable from every other node in
|
|
// the SCC.
|
|
for (unsigned i = 0; i != NUM_NODES; ++i)
|
|
if (NodesInThisSCC.count(i)) {
|
|
EXPECT_TRUE(NodesInThisSCC.isSubsetOf(G.NodesReachableFrom(i)));
|
|
}
|
|
|
|
// OK, now that we now that every node in the SCC is reachable from every
|
|
// other, this means that the set of nodes reachable from any node in the
|
|
// SCC is the same as the set of nodes reachable from every node in the
|
|
// SCC. Check that for every node N not in the SCC but reachable from the
|
|
// SCC, no element of the SCC is reachable from N.
|
|
for (unsigned i = 0; i != NUM_NODES; ++i)
|
|
if (NodesInThisSCC.count(i)) {
|
|
GT::NodeSubset NodesReachableFromSCC = G.NodesReachableFrom(i);
|
|
GT::NodeSubset ReachableButNotInSCC =
|
|
NodesReachableFromSCC.Meet(NodesInThisSCC.Complement());
|
|
|
|
for (unsigned j = 0; j != NUM_NODES; ++j)
|
|
if (ReachableButNotInSCC.count(j)) {
|
|
EXPECT_TRUE(G.NodesReachableFrom(j).Meet(NodesInThisSCC).isEmpty());
|
|
}
|
|
|
|
// The result must be the same for all other nodes in this SCC, so
|
|
// there is no point in checking them.
|
|
break;
|
|
}
|
|
|
|
// This is indeed a SCC: a maximal set of nodes for which each node is
|
|
// reachable from every other.
|
|
|
|
// Check that we didn't already see this SCC.
|
|
EXPECT_TRUE(NodesInSomeSCC.Meet(NodesInThisSCC).isEmpty());
|
|
|
|
NodesInSomeSCC = NodesInSomeSCC.Join(NodesInThisSCC);
|
|
|
|
// Check a property that is specific to the LLVM SCC iterator and
|
|
// guaranteed by it: if a node in SCC S1 has an edge to a node in
|
|
// SCC S2, then S1 is visited *after* S2. This means that the set
|
|
// of nodes reachable from this SCC must be contained either in the
|
|
// union of this SCC and all previously visited SCC's.
|
|
|
|
for (unsigned i = 0; i != NUM_NODES; ++i)
|
|
if (NodesInThisSCC.count(i)) {
|
|
GT::NodeSubset NodesReachableFromSCC = G.NodesReachableFrom(i);
|
|
EXPECT_TRUE(NodesReachableFromSCC.isSubsetOf(NodesInSomeSCC));
|
|
// The result must be the same for all other nodes in this SCC, so
|
|
// there is no point in checking them.
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Finally, check that the nodes in some SCC are exactly those that are
|
|
// reachable from the initial node.
|
|
EXPECT_EQ(NodesInSomeSCC, G.NodesReachableFrom(0));
|
|
}
|
|
}
|
|
|
|
}
|