Author: resistor
Date: Tue Jul 24 16:31:23 2007
New Revision: 40474
URL: http://llvm.org/viewvc/llvm-project?rev=40474&view=rev
Log:
Make the copy constructor of SmallPtrSet much faster.
Modified:
llvm/trunk/lib/Support/SmallPtrSet.cpp
Modified: llvm/trunk/lib/Support/SmallPtrSet.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/SmallPtrSet.cpp?rev=40474&r1=40473&r2=40474&view=diff
==============================================================================
--- llvm/trunk/lib/Support/SmallPtrSet.cpp (original)
+++ llvm/trunk/lib/Support/SmallPtrSet.cpp Tue Jul 24 16:31:23 2007
@@ -149,33 +149,23 @@
}
SmallPtrSetImpl::SmallPtrSetImpl(const SmallPtrSetImpl& that) {
- NumElements = that.NumElements;
- NumTombstones = 0;
+ // If we're becoming small, prepare to insert into our stack space
if (that.isSmall()) {
- CurArraySize = that.CurArraySize;
CurArray = &SmallArray[0];
- // Copy the entire contents of the array, including the -1's and the null
- // terminator.
- memcpy(CurArray, that.CurArray, sizeof(void*)*(CurArraySize+1));
+ // Otherwise, allocate new heap space (unless we were the same size)
} else {
- CurArraySize = that.NumElements < 64 ? 128 : that.CurArraySize*2;
- CurArray = (void**)malloc(sizeof(void*) * (CurArraySize+1));
+ CurArray = (void**)malloc(sizeof(void*) * (that.CurArraySize+1));
assert(CurArray && "Failed to allocate memory?");
- memset(CurArray, -1, CurArraySize*sizeof(void*));
-
- // The end pointer, always valid, is set to a valid element to help the
- // iterator.
- CurArray[CurArraySize] = 0;
-
- // Copy over all valid entries.
- for (void **BucketPtr = that.CurArray, **E =
that.CurArray+that.CurArraySize;
- BucketPtr != E; ++BucketPtr) {
- // Copy over the element if it is valid.
- void *Elt = *BucketPtr;
- if (Elt != getTombstoneMarker() && Elt != getEmptyMarker())
- *const_cast<void**>(FindBucketFor(Elt)) = Elt;
- }
}
+
+ // Copy over the new array size
+ CurArraySize = that.CurArraySize;
+
+ // Copy over the contents from the other set
+ memcpy(CurArray, that.CurArray, sizeof(void*)*(CurArraySize+1));
+
+ NumElements = that.NumElements;
+ NumTombstones = that.NumTombstones;
}
/// CopyFrom - implement operator= from a smallptrset that has the same pointer
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