Enhance verifyLoop so that it can reliably verify that every block in a loop is reachable from the loop header.

llvm-svn: 144166
This commit is contained in:
Eli Friedman 2011-11-09 04:16:01 +00:00
parent 2eda1daed3
commit 3a47854e40

View File

@ -416,14 +416,26 @@ public:
#ifndef NDEBUG
assert(!Blocks.empty() && "Loop header is missing");
// Setup for using a depth-first iterator to visit every block in the loop.
SmallVector<BlockT*, 8> ExitBBs;
getExitBlocks(ExitBBs);
llvm::SmallPtrSet<BlockT*, 8> VisitSet;
VisitSet.insert(ExitBBs.begin(), ExitBBs.end());
df_ext_iterator<BlockT*, llvm::SmallPtrSet<BlockT*, 8> >
BI = df_ext_begin(getHeader(), VisitSet),
BE = df_ext_end(getHeader(), VisitSet);
// Keep track of the number of BBs visited.
unsigned NumVisited = 0;
// Sort the blocks vector so that we can use binary search to do quick
// lookups.
SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end());
std::sort(LoopBBs.begin(), LoopBBs.end());
// Check the individual blocks.
for (block_iterator I = block_begin(), E = block_end(); I != E; ++I) {
BlockT *BB = *I;
for ( ; BI != BE; ++BI) {
BlockT *BB = *BI;
bool HasInsideLoopSuccs = false;
bool HasInsideLoopPreds = false;
SmallVector<BlockT *, 2> OutsideLoopPreds;
@ -440,7 +452,7 @@ public:
for (typename InvBlockTraits::ChildIteratorType PI =
InvBlockTraits::child_begin(BB), PE = InvBlockTraits::child_end(BB);
PI != PE; ++PI) {
typename InvBlockTraits::NodeType *N = *PI;
BlockT *N = *PI;
if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), N))
HasInsideLoopPreds = true;
else
@ -464,8 +476,12 @@ public:
assert(HasInsideLoopSuccs && "Loop block has no in-loop successors!");
assert(BB != getHeader()->getParent()->begin() &&
"Loop contains function entry block!");
NumVisited++;
}
assert(NumVisited == getNumBlocks() && "Unreachable block in loop");
// Check the subloops.
for (iterator I = begin(), E = end(); I != E; ++I)
// Each block in each subloop should be contained within this loop.