Add a clear() method to FoldingSet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55210 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2008-08-23 00:42:16 +00:00
parent 169b5ed46e
commit 535de1a8c1
2 changed files with 16 additions and 12 deletions

View File

@ -143,6 +143,9 @@ public:
void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; }
};
/// clear - Remove all nodes from the folding set.
void clear();
/// RemoveNode - Remove a node from the folding set, returning true if one
/// was removed or false if the node was not in the folding set.
bool RemoveNode(Node *N);

View File

@ -200,19 +200,26 @@ static void **GetBucketFor(const FoldingSetNodeID &ID,
//===----------------------------------------------------------------------===//
// FoldingSetImpl Implementation
FoldingSetImpl::FoldingSetImpl(unsigned Log2InitSize) : NumNodes(0) {
FoldingSetImpl::FoldingSetImpl(unsigned Log2InitSize) {
assert(5 < Log2InitSize && Log2InitSize < 32 &&
"Initial hash table size out of range");
NumBuckets = 1 << Log2InitSize;
Buckets = new void*[NumBuckets+1];
memset(Buckets, 0, NumBuckets*sizeof(void*));
// Set the very last bucket to be a non-null "pointer".
Buckets[NumBuckets] = reinterpret_cast<void*>(-1);
clear();
}
FoldingSetImpl::~FoldingSetImpl() {
delete [] Buckets;
}
void FoldingSetImpl::clear() {
// Set all but the last bucket to null pointers.
memset(Buckets, 0, NumBuckets*sizeof(void*));
// Set the very last bucket to be a non-null "pointer".
Buckets[NumBuckets] = reinterpret_cast<void*>(-1);
// Reset the node count to zero.
NumNodes = 0;
}
/// GrowHashTable - Double the size of the hash table and rehash everything.
///
@ -221,15 +228,9 @@ void FoldingSetImpl::GrowHashTable() {
unsigned OldNumBuckets = NumBuckets;
NumBuckets <<= 1;
// Reset the node count to zero: we're going to reinsert everything.
NumNodes = 0;
// Clear out new buckets.
Buckets = new void*[NumBuckets+1];
memset(Buckets, 0, NumBuckets*sizeof(void*));
// Set the very last bucket to be a non-null "pointer".
Buckets[NumBuckets] = reinterpret_cast<void*>(-1);
clear();
// Walk the old buckets, rehashing nodes into their new place.
FoldingSetNodeID ID;