//===----------------------------------------------------------------------===//
#include "llvm/ADT/FoldingSet.h"
-
-#include "llvm/ADT/MathExtras.h"
-
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
using namespace llvm;
//===----------------------------------------------------------------------===//
}
void FoldingSetImpl::NodeID::AddInteger(uint64_t I) {
Bits.push_back(unsigned(I));
- Bits.push_back(unsigned(I >> 32));
+
+ // If the integer is small, encode it just as 32-bits.
+ if ((uint64_t)(int)I != I)
+ Bits.push_back(unsigned(I >> 32));
}
void FoldingSetImpl::NodeID::AddFloat(float F) {
Bits.push_back(FloatToBits(F));
}
void FoldingSetImpl::NodeID::AddDouble(double D) {
- Bits.push_back(DoubleToBits(D));
+ AddInteger(DoubleToBits(D));
}
void FoldingSetImpl::NodeID::AddString(const std::string &String) {
- // Note: An assumption is made here that strings are composed of one byte
- // chars.
unsigned Size = String.size();
- unsigned Units = Size / sizeof(unsigned);
+ Bits.push_back(Size);
+ if (!Size) return;
+
+ unsigned Units = Size / 4;
+ unsigned Pos = 0;
const unsigned *Base = (const unsigned *)String.data();
- Bits.insert(Bits.end(), Base, Base + Units);
- if (Size & 3) {
- unsigned V = 0;
- for (unsigned i = Units * sizeof(unsigned); i < Size; ++i)
- V = (V << 8) | String[i];
- Bits.push_back(V);
+
+ // If the string is aligned do a bulk transfer.
+ if (!((intptr_t)Base & 3)) {
+ Bits.append(Base, Base + Units);
+ Pos = (Units + 1) * 4;
+ } else {
+ // Otherwise do it the hard way.
+ for ( Pos += 4; Pos <= Size; Pos += 4) {
+ unsigned V = ((unsigned char)String[Pos - 4] << 24) |
+ ((unsigned char)String[Pos - 3] << 16) |
+ ((unsigned char)String[Pos - 2] << 8) |
+ (unsigned char)String[Pos - 1];
+ Bits.push_back(V);
+ }
+ }
+
+ // With the leftover bits.
+ unsigned V = 0;
+ // Pos will have overshot size by 4 - #bytes left over.
+ switch (Pos - Size) {
+ case 1: V = (V << 8) | (unsigned char)String[Size - 3]; // Fall thru.
+ case 2: V = (V << 8) | (unsigned char)String[Size - 2]; // Fall thru.
+ case 3: V = (V << 8) | (unsigned char)String[Size - 1]; break;
+ default: return; // Nothing left.
}
+
+ Bits.push_back(V);
}
/// ComputeHash - Compute a strong hash value for this NodeID, used to
//===----------------------------------------------------------------------===//
-// FoldingSetImpl Implementation
-
-FoldingSetImpl::FoldingSetImpl() : NumNodes(0) {
- NumBuckets = 64;
- Buckets = new void*[NumBuckets];
- memset(Buckets, 0, NumBuckets*sizeof(void*));
-}
-FoldingSetImpl::~FoldingSetImpl() {
- delete [] Buckets;
-}
+/// Helper functions for FoldingSetImpl.
/// GetNextPtr - In order to save space, each bucket is a
/// singly-linked-list. In order to make deletion more efficient, we make
/// the list circular, so we can delete a node without computing its hash.
/// The problem with this is that the start of the hash buckets are not
-/// Nodes. If NextInBucketPtr is a bucket pointer, this method returns null
-/// : use GetBucketPtr when this happens.
-FoldingSetImpl::Node *FoldingSetImpl::GetNextPtr(void *NextInBucketPtr) {
- if (NextInBucketPtr >= Buckets && NextInBucketPtr < Buckets+NumBuckets)
- return 0;
- return static_cast<Node*>(NextInBucketPtr);
-}
-
-/// GetNextPtr - This is just like the previous GetNextPtr implementation,
-/// but allows a bucket array to be specified.
-FoldingSetImpl::Node *FoldingSetImpl::GetNextPtr(void *NextInBucketPtr,
- void **Bucks,
- unsigned NumBuck) {
- if (NextInBucketPtr >= Bucks && NextInBucketPtr < Bucks+NumBuck)
+/// Nodes. If NextInBucketPtr is a bucket pointer, this method returns null:
+/// use GetBucketPtr when this happens.
+static FoldingSetImpl::Node *GetNextPtr(void *NextInBucketPtr,
+ void **Buckets, unsigned NumBuckets) {
+ if (NextInBucketPtr >= Buckets && NextInBucketPtr < Buckets + NumBuckets)
return 0;
- return static_cast<Node*>(NextInBucketPtr);
+ return static_cast<FoldingSetImpl::Node*>(NextInBucketPtr);
}
/// GetBucketPtr - Provides a casting of a bucket pointer for isNode
/// testing.
-void **FoldingSetImpl::GetBucketPtr(void *NextInBucketPtr) {
+static void **GetBucketPtr(void *NextInBucketPtr) {
return static_cast<void**>(NextInBucketPtr);
}
/// GetBucketFor - Hash the specified node ID and return the hash bucket for
/// the specified ID.
-void **FoldingSetImpl::GetBucketFor(const NodeID &ID) const {
+static void **GetBucketFor(const FoldingSetImpl::NodeID &ID,
+ void **Buckets, unsigned NumBuckets) {
// NumBuckets is always a power of 2.
unsigned BucketNum = ID.ComputeHash() & (NumBuckets-1);
- return Buckets+BucketNum;
+ return Buckets + BucketNum;
+}
+
+//===----------------------------------------------------------------------===//
+// FoldingSetImpl Implementation
+
+FoldingSetImpl::FoldingSetImpl(unsigned Log2InitSize) : NumNodes(0) {
+ assert(5 < Log2InitSize && Log2InitSize < 32 &&
+ "Initial hash table size out of range");
+ NumBuckets = 1 << Log2InitSize;
+ Buckets = new void*[NumBuckets];
+ memset(Buckets, 0, NumBuckets*sizeof(void*));
+}
+FoldingSetImpl::~FoldingSetImpl() {
+ delete [] Buckets;
}
/// GrowHashTable - Double the size of the hash table and rehash everything.
for (unsigned i = 0; i != OldNumBuckets; ++i) {
void *Probe = OldBuckets[i];
if (!Probe) continue;
- while (Node *NodeInBucket = GetNextPtr(Probe, OldBuckets, OldNumBuckets)){
+ while (Node *NodeInBucket = GetNextPtr(Probe, OldBuckets, OldNumBuckets)) {
// Figure out the next link, remove NodeInBucket from the old link.
Probe = NodeInBucket->getNextInBucket();
NodeInBucket->SetNextInBucket(0);
// Insert the node into the new bucket, after recomputing the hash.
NodeID ID;
GetNodeProfile(ID, NodeInBucket);
- InsertNode(NodeInBucket, GetBucketFor(ID));
+ InsertNode(NodeInBucket, GetBucketFor(ID, Buckets, NumBuckets));
}
}
/// faster.
FoldingSetImpl::Node *FoldingSetImpl::FindNodeOrInsertPos(const NodeID &ID,
void *&InsertPos) {
- void **Bucket = GetBucketFor(ID);
+ void **Bucket = GetBucketFor(ID, Buckets, NumBuckets);
void *Probe = *Bucket;
InsertPos = 0;
- while (Node *NodeInBucket = GetNextPtr(Probe)) {
+ while (Node *NodeInBucket = GetNextPtr(Probe, Buckets, NumBuckets)) {
NodeID OtherID;
GetNodeProfile(OtherID, NodeInBucket);
if (OtherID == ID)
/// is not already in the map. InsertPos must be obtained from
/// FindNodeOrInsertPos.
void FoldingSetImpl::InsertNode(Node *N, void *InsertPos) {
- ++NumNodes;
+ assert(N->getNextInBucket() == 0);
// Do we need to grow the hashtable?
- if (NumNodes > NumBuckets*2) {
+ if (NumNodes+1 > NumBuckets*2) {
GrowHashTable();
NodeID ID;
GetNodeProfile(ID, N);
- InsertPos = GetBucketFor(ID);
+ InsertPos = GetBucketFor(ID, Buckets, NumBuckets);
}
+
+ ++NumNodes;
/// The insert position is actually a bucket pointer.
void **Bucket = static_cast<void**>(InsertPos);
if (Next == 0)
Next = Bucket;
- // Set the nodes next pointer, and make the bucket point to the node.
+ // Set the node's next pointer, and make the bucket point to the node.
N->SetNextInBucket(Next);
*Bucket = N;
}
/// removed or false if the node was not in the folding set.
bool FoldingSetImpl::RemoveNode(Node *N) {
// Because each bucket is a circular list, we don't need to compute N's hash
- // to remove it. Chase around the list until we find the node (or bucket)
- // which points to N.
+ // to remove it.
void *Ptr = N->getNextInBucket();
if (Ptr == 0) return false; // Not in folding set.
--NumNodes;
+ N->SetNextInBucket(0);
+ // Remember what N originally pointed to, either a bucket or another node.
void *NodeNextPtr = Ptr;
- N->SetNextInBucket(0);
+
+ // Chase around the list until we find the node (or bucket) which points to N.
while (true) {
- if (Node *NodeInBucket = GetNextPtr(Ptr)) {
+ if (Node *NodeInBucket = GetNextPtr(Ptr, Buckets, NumBuckets)) {
// Advance pointer.
Ptr = NodeInBucket->getNextInBucket();
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