//
//===----------------------------------------------------------------------===//
//
-// This file implements the SmallPtrSet class.
+// This file implements the SmallPtrSet class. See SmallPtrSet.h for an
+// overview of the algorithm.
//
//===----------------------------------------------------------------------===//
}
// If more than 3/4 of the array is full, grow.
- if (NumElements*4 >= CurArraySize*3)
+ if (NumElements*4 >= CurArraySize*3 ||
+ CurArraySize-(NumElements+NumTombstones) < CurArraySize/8)
Grow();
// Okay, we know we have space. Find a hash bucket.
if (*Bucket == Ptr) return false; // Already inserted, good.
// Otherwise, insert it!
+ if (*Bucket == getTombstoneMarker())
+ --NumTombstones;
*Bucket = Ptr;
++NumElements; // Track density.
return true;
}
+bool SmallPtrSetImpl::erase(void *Ptr) {
+ if (isSmall()) {
+ // Check to see if it is in the set.
+ for (void **APtr = SmallArray, **E = SmallArray+NumElements;
+ APtr != E; ++APtr)
+ if (*APtr == Ptr) {
+ // If it is in the set, move everything over, replacing this element.
+ memmove(APtr, APtr+1, sizeof(void*)*(E-APtr-1));
+ // Clear the end element.
+ E[-1] = getEmptyMarker();
+ --NumElements;
+ return true;
+ }
+
+ return false;
+ }
+
+ // Okay, we know we have space. Find a hash bucket.
+ void **Bucket = const_cast<void**>(FindBucketFor(Ptr));
+ if (*Bucket != Ptr) return false; // Not in the set?
+
+ // Set this as a tombstone.
+ *Bucket = getTombstoneMarker();
+ --NumElements;
+ ++NumTombstones;
+ return true;
+}
+
void * const *SmallPtrSetImpl::FindBucketFor(void *Ptr) const {
unsigned Bucket = Hash(Ptr);
unsigned ArraySize = CurArraySize;