#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
+#ifndef LLVM_SUPPORT_PREDITERATORCACHE_H
+#define LLVM_SUPPORT_PREDITERATORCACHE_H
+
namespace llvm {
/// PredIteratorCache - This class is an extremely trivial cache for
class PredIteratorCache {
/// BlockToPredsMap - Pointer to null-terminated list.
DenseMap<BasicBlock*, BasicBlock**> BlockToPredsMap;
+ DenseMap<BasicBlock*, unsigned> BlockToPredCountMap;
/// Memory - This is the space that holds cached preds.
BumpPtrAllocator Memory;
public:
-
+
/// GetPreds - Get a cached list for the null-terminated predecessor list of
/// the specified block. This can be used in a loop like this:
/// for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI)
BasicBlock **GetPreds(BasicBlock *BB) {
BasicBlock **&Entry = BlockToPredsMap[BB];
if (Entry) return Entry;
-
+
SmallVector<BasicBlock*, 32> PredCache(pred_begin(BB), pred_end(BB));
PredCache.push_back(0); // null terminator.
+ BlockToPredCountMap[BB] = PredCache.size()-1;
+
Entry = Memory.Allocate<BasicBlock*>(PredCache.size());
std::copy(PredCache.begin(), PredCache.end(), Entry);
return Entry;
}
+ unsigned GetNumPreds(BasicBlock *BB) {
+ GetPreds(BB);
+ return BlockToPredCountMap[BB];
+ }
+
/// clear - Remove all information.
void clear() {
BlockToPredsMap.clear();
+ BlockToPredCountMap.clear();
Memory.Reset();
}
};
} // end namespace llvm
+#endif