Two changes:

1. Make SmallPtrSet::erase faster in the small case by replacing a memmove
    with a pointer copy.
 2. Fix a bug where the null terminator at the end of the array in the small
    case was not copied


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37696 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2007-06-21 23:23:32 +00:00
parent 25e681ac22
commit 61766cae0b

View File

@@ -54,9 +54,8 @@ bool SmallPtrSetImpl::erase(void *Ptr) {
for (void **APtr = SmallArray, **E = SmallArray+NumElements; for (void **APtr = SmallArray, **E = SmallArray+NumElements;
APtr != E; ++APtr) APtr != E; ++APtr)
if (*APtr == Ptr) { if (*APtr == Ptr) {
// If it is in the set, move everything over, replacing this element. // If it is in the set, replace this element.
memmove(APtr, APtr+1, sizeof(void*)*(E-APtr-1)); *APtr = E[-1];
// Clear the end element.
E[-1] = getEmptyMarker(); E[-1] = getEmptyMarker();
--NumElements; --NumElements;
return true; return true;
@@ -151,7 +150,9 @@ SmallPtrSetImpl::SmallPtrSetImpl(const SmallPtrSetImpl& that) {
if (that.isSmall()) { if (that.isSmall()) {
CurArraySize = that.CurArraySize; CurArraySize = that.CurArraySize;
CurArray = &SmallArray[0]; CurArray = &SmallArray[0];
memcpy(CurArray, that.CurArray, sizeof(void*)*CurArraySize); // Copy the entire contents of the array, including the -1's and the null
// terminator.
memcpy(CurArray, that.CurArray, sizeof(void*)*(CurArraySize+1));
} else { } else {
CurArraySize = that.NumElements < 64 ? 128 : that.NumElements*2; CurArraySize = that.NumElements < 64 ? 128 : that.NumElements*2;
CurArray = new void*[CurArraySize+1]; CurArray = new void*[CurArraySize+1];