void FoldingSetImpl::GrowBucketCount(unsigned NewBucketCount) {
assert((NewBucketCount > NumBuckets) && "Can't shrink a folding set with GrowBucketCount");
assert(isPowerOf2_32(NewBucketCount) && "Bad bucket count!");
void **OldBuckets = Buckets;
unsigned OldNumBuckets = NumBuckets;
NumBuckets = NewBucketCount;
// Clear out new buckets.
Buckets = AllocateBuckets(NumBuckets);
NumNodes = 0;
// Walk the old buckets, rehashing nodes into their new place.
FoldingSetNodeID TempID;
for (unsigned i = 0; i != OldNumBuckets; ++i) {
void *Probe = OldBuckets[i];
if (!Probe) continue;
while (Node *NodeInBucket = GetNextPtr(Probe)) {
// Figure out the next link, remove NodeInBucket from the old link.
Probe = NodeInBucket->getNextInBucket();
NodeInBucket->SetNextInBucket(nullptr);
// Insert the node into the new bucket, after recomputing the hash.
InsertNode(NodeInBucket,
GetBucketFor(ComputeNodeHash(NodeInBucket, TempID),
Buckets, NumBuckets));
TempID.clear();
}
}
free(OldBuckets);
}
/// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
/// return it. If not, return the insertion token that will make insertion
/// faster.
FoldingSetImpl::Node
*FoldingSetImpl::FindNodeOrInsertPos(const FoldingSetNodeID &ID,
void *&InsertPos) {
unsigned IDHash = ID.ComputeHash();
void **Bucket = GetBucketFor(IDHash, Buckets, NumBuckets);
void *Probe = *Bucket;
InsertPos = nullptr;
FoldingSetNodeID TempID;
while (Node *NodeInBucket = GetNextPtr(Probe)) {
if (NodeEquals(NodeInBucket, ID, IDHash, TempID))
return NodeInBucket;
TempID.clear();
Probe = NodeInBucket->getNextInBucket();
}
// Didn't find the node, return null with the bucket as the InsertPos.
InsertPos = Bucket;
return nullptr;
}