[llvm-commits] [llvm] r152143 - in /llvm/trunk: include/llvm/ADT/SmallPtrSet.h lib/Support/SmallPtrSet.cpp unittests/ADT/SmallPtrSetTest.cpp
Benjamin Kramer
benny.kra at googlemail.com
Tue Mar 6 12:40:02 PST 2012
Author: d0k
Date: Tue Mar 6 14:40:02 2012
New Revision: 152143
URL: http://llvm.org/viewvc/llvm-project?rev=152143&view=rev
Log:
SmallPtrSet: Provide a more efficient implementation of swap than the default triple-copy std::swap.
This currently assumes that both sets have the same SmallSize to keep the implementation simple,
a limitation that can be lifted if someone cares.
Added:
llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp
Modified:
llvm/trunk/include/llvm/ADT/SmallPtrSet.h
llvm/trunk/lib/Support/SmallPtrSet.cpp
Modified: llvm/trunk/include/llvm/ADT/SmallPtrSet.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SmallPtrSet.h?rev=152143&r1=152142&r2=152143&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SmallPtrSet.h (original)
+++ llvm/trunk/include/llvm/ADT/SmallPtrSet.h Tue Mar 6 14:40:02 2012
@@ -137,6 +137,10 @@
void operator=(const SmallPtrSetImpl &RHS); // DO NOT IMPLEMENT.
protected:
+ /// swap - Swaps the elements of two sets.
+ /// Note: This method assumes that both sets have the same small size.
+ void swap(SmallPtrSetImpl &RHS);
+
void CopyFrom(const SmallPtrSetImpl &RHS);
};
@@ -287,8 +291,20 @@
return *this;
}
+ /// swap - Swaps the elements of two sets.
+ void swap(SmallPtrSet<PtrType, SmallSize> &RHS) {
+ SmallPtrSetImpl::swap(RHS);
+ }
};
}
+namespace std {
+ /// Implement std::swap in terms of SmallPtrSet swap.
+ template<class T, unsigned N>
+ inline void swap(llvm::SmallPtrSet<T, N> &LHS, llvm::SmallPtrSet<T, N> &RHS) {
+ LHS.swap(RHS);
+ }
+}
+
#endif
Modified: llvm/trunk/lib/Support/SmallPtrSet.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/SmallPtrSet.cpp?rev=152143&r1=152142&r2=152143&view=diff
==============================================================================
--- llvm/trunk/lib/Support/SmallPtrSet.cpp (original)
+++ llvm/trunk/lib/Support/SmallPtrSet.cpp Tue Mar 6 14:40:02 2012
@@ -14,6 +14,7 @@
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/MathExtras.h"
+#include <algorithm>
#include <cstdlib>
using namespace llvm;
@@ -223,6 +224,55 @@
NumTombstones = RHS.NumTombstones;
}
+void SmallPtrSetImpl::swap(SmallPtrSetImpl &RHS) {
+ if (this == &RHS) return;
+
+ // We can only avoid copying elements if neither set is small.
+ if (!this->isSmall() && !RHS.isSmall()) {
+ std::swap(this->CurArray, RHS.CurArray);
+ std::swap(this->CurArraySize, RHS.CurArraySize);
+ std::swap(this->NumElements, RHS.NumElements);
+ std::swap(this->NumTombstones, RHS.NumTombstones);
+ return;
+ }
+
+ // FIXME: From here on we assume that both sets have the same small size.
+
+ // If only RHS is small, copy the small elements into LHS and move the pointer
+ // from LHS to RHS.
+ if (!this->isSmall() && RHS.isSmall()) {
+ std::copy(RHS.SmallArray, RHS.SmallArray+RHS.NumElements, this->SmallArray);
+ std::swap(this->NumElements, RHS.NumElements);
+ std::swap(this->CurArraySize, RHS.CurArraySize);
+ RHS.CurArray = this->CurArray;
+ RHS.NumTombstones = this->NumTombstones;
+ this->CurArray = this->SmallArray;
+ this->NumTombstones = 0;
+ return;
+ }
+
+ // If only LHS is small, copy the small elements into RHS and move the pointer
+ // from RHS to LHS.
+ if (this->isSmall() && !RHS.isSmall()) {
+ std::copy(this->SmallArray, this->SmallArray+this->NumElements,
+ RHS.SmallArray);
+ std::swap(RHS.NumElements, this->NumElements);
+ std::swap(RHS.CurArraySize, this->CurArraySize);
+ this->CurArray = RHS.CurArray;
+ this->NumTombstones = RHS.NumTombstones;
+ RHS.CurArray = RHS.SmallArray;
+ RHS.NumTombstones = 0;
+ return;
+ }
+
+ // Both a small, just swap the small elements.
+ assert(this->isSmall() && RHS.isSmall());
+ assert(this->CurArraySize == RHS.CurArraySize);
+ unsigned MaxElems = std::max(this->NumElements, RHS.NumElements);
+ std::swap_ranges(this->SmallArray, this->SmallArray+MaxElems, RHS.SmallArray);
+ std::swap(this->NumElements, RHS.NumElements);
+}
+
SmallPtrSetImpl::~SmallPtrSetImpl() {
if (!isSmall())
free(CurArray);
Added: llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp?rev=152143&view=auto
==============================================================================
--- llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp (added)
+++ llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp Tue Mar 6 14:40:02 2012
@@ -0,0 +1,72 @@
+//===- llvm/unittest/ADT/SmallPtrSetTest.cpp ------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// SmallPtrSet unit tests.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+#include "llvm/ADT/SmallPtrSet.h"
+
+using namespace llvm;
+
+// SmallPtrSet swapping test.
+TEST(SmallPtrSetTest, SwapTest) {
+ int buf[10];
+
+ SmallPtrSet<int *, 2> a;
+ SmallPtrSet<int *, 2> b;
+
+ a.insert(&buf[0]);
+ a.insert(&buf[1]);
+ b.insert(&buf[2]);
+
+ std::swap(a, b);
+
+ EXPECT_EQ(1U, a.size());
+ EXPECT_EQ(2U, b.size());
+ EXPECT_TRUE(a.count(&buf[2]));
+ EXPECT_TRUE(b.count(&buf[0]));
+ EXPECT_TRUE(b.count(&buf[1]));
+
+ b.insert(&buf[3]);
+ std::swap(a, b);
+
+ EXPECT_EQ(3U, a.size());
+ EXPECT_EQ(1U, b.size());
+ EXPECT_TRUE(a.count(&buf[0]));
+ EXPECT_TRUE(a.count(&buf[1]));
+ EXPECT_TRUE(a.count(&buf[3]));
+ EXPECT_TRUE(b.count(&buf[2]));
+
+ std::swap(a, b);
+
+ EXPECT_EQ(1U, a.size());
+ EXPECT_EQ(3U, b.size());
+ EXPECT_TRUE(a.count(&buf[2]));
+ EXPECT_TRUE(b.count(&buf[0]));
+ EXPECT_TRUE(b.count(&buf[1]));
+ EXPECT_TRUE(b.count(&buf[3]));
+
+ a.insert(&buf[4]);
+ a.insert(&buf[5]);
+ a.insert(&buf[6]);
+
+ std::swap(b, a);
+
+ EXPECT_EQ(3U, a.size());
+ EXPECT_EQ(4U, b.size());
+ EXPECT_TRUE(b.count(&buf[2]));
+ EXPECT_TRUE(b.count(&buf[4]));
+ EXPECT_TRUE(b.count(&buf[5]));
+ EXPECT_TRUE(b.count(&buf[6]));
+ EXPECT_TRUE(a.count(&buf[0]));
+ EXPECT_TRUE(a.count(&buf[1]));
+ EXPECT_TRUE(a.count(&buf[3]));
+}
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