llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Utkarsh Saxena (usx95) <details> <summary>Changes</summary> Optimize ImmutableSet operations to avoid unnecessary tree modifications when adding existing elements or removing non-existent elements. - Modified `ImutAVLFactory::add_internal()` to return the original tree when both key and value are the same, avoiding unnecessary node creation - Updated `ImutAVLFactory::remove_internal()` and `add_internal()` to return the original tree when no changes are made. Note that `balanceTree` always end up creating at least one node even when no rebalancing is done. So we also need to avoid unnecessary calls to it. --- Full diff: https://github.com/llvm/llvm-project/pull/159845.diff 3 Files Affected: - (modified) clang/lib/Analysis/LifetimeSafety.cpp (+4-8) - (modified) llvm/include/llvm/ADT/ImmutableSet.h (+34-14) - (modified) llvm/unittests/ADT/ImmutableSetTest.cpp (+33) ``````````diff diff --git a/clang/lib/Analysis/LifetimeSafety.cpp b/clang/lib/Analysis/LifetimeSafety.cpp index d016c6f12e82e..0dd5716d93fb6 100644 --- a/clang/lib/Analysis/LifetimeSafety.cpp +++ b/clang/lib/Analysis/LifetimeSafety.cpp @@ -910,13 +910,10 @@ template <typename T> static llvm::ImmutableSet<T> join(llvm::ImmutableSet<T> A, llvm::ImmutableSet<T> B, typename llvm::ImmutableSet<T>::Factory &F) { - if (A == B) - return A; if (A.getHeight() < B.getHeight()) std::swap(A, B); for (const T &E : B) - if (!A.contains(E)) - A = F.add(A, E); + A = F.add(A, E); return A; } @@ -950,11 +947,10 @@ join(llvm::ImmutableMap<K, V> A, llvm::ImmutableMap<K, V> B, for (const auto &Entry : B) { const K &Key = Entry.first; const V &ValB = Entry.second; - const V *ValA = A.lookup(Key); - if (!ValA) - A = F.add(A, Key, ValB); - else if (*ValA != ValB) + if (const V *ValA = A.lookup(Key)) A = F.add(A, Key, JoinValues(*ValA, ValB)); + else + A = F.add(A, Key, ValB); } return A; } diff --git a/llvm/include/llvm/ADT/ImmutableSet.h b/llvm/include/llvm/ADT/ImmutableSet.h index ac86f43b2048e..c2d84d86b5e27 100644 --- a/llvm/include/llvm/ADT/ImmutableSet.h +++ b/llvm/include/llvm/ADT/ImmutableSet.h @@ -531,7 +531,7 @@ class ImutAVLFactory { /// add_internal - Creates a new tree that includes the specified /// data and the data from the original tree. If the original tree /// already contained the data item, the original tree is returned. - TreeTy* add_internal(value_type_ref V, TreeTy* T) { + TreeTy *add_internal(value_type_ref V, TreeTy *T) { if (isEmpty(T)) return createNode(T, V, T); assert(!T->isMutable()); @@ -539,19 +539,34 @@ class ImutAVLFactory { key_type_ref K = ImutInfo::KeyOfValue(V); key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); - if (ImutInfo::isEqual(K,KCurrent)) + if (ImutInfo::isEqual(K, KCurrent)) { + // If both key and value are same, return the original tree. + if (ImutInfo::isDataEqual(ImutInfo::DataOfValue(V), + ImutInfo::DataOfValue(getValue(T)))) + return T; + // Otherwise create a new node with the new value. return createNode(getLeft(T), V, getRight(T)); - else if (ImutInfo::isLess(K,KCurrent)) - return balanceTree(add_internal(V, getLeft(T)), getValue(T), getRight(T)); + } + + TreeTy *NewL = getLeft(T); + TreeTy *NewR = getRight(T); + if (ImutInfo::isLess(K, KCurrent)) + NewL = add_internal(V, NewL); else - return balanceTree(getLeft(T), getValue(T), add_internal(V, getRight(T))); + NewR = add_internal(V, NewR); + + // If no changes were made, return the original tree. Otherwise, balance the + // tree and return the new root. + return NewL == getLeft(T) && NewR == getRight(T) + ? T + : balanceTree(NewL, getValue(T), NewR); } /// remove_internal - Creates a new tree that includes all the data /// from the original tree except the specified data. If the /// specified data did not exist in the original tree, the original /// tree is returned. - TreeTy* remove_internal(key_type_ref K, TreeTy* T) { + TreeTy* remove_internal(key_type_ref K, TreeTy* T) { if (isEmpty(T)) return T; @@ -559,15 +574,20 @@ class ImutAVLFactory { key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); - if (ImutInfo::isEqual(K,KCurrent)) { + if (ImutInfo::isEqual(K, KCurrent)) return combineTrees(getLeft(T), getRight(T)); - } else if (ImutInfo::isLess(K,KCurrent)) { - return balanceTree(remove_internal(K, getLeft(T)), - getValue(T), getRight(T)); - } else { - return balanceTree(getLeft(T), getValue(T), - remove_internal(K, getRight(T))); - } + + TreeTy *NewL = getLeft(T); + TreeTy *NewR = getRight(T); + if (ImutInfo::isLess(K, KCurrent)) + NewL = remove_internal(K, NewL); + else + NewR = remove_internal(K, NewR); + + // If no changes were made, return the original tree. Otherwise, balance the + // tree and return the new root. + return NewL == getLeft(T) && NewR == getRight(T) ? T + : balanceTree(NewL, getValue(T), NewR); } TreeTy* combineTrees(TreeTy* L, TreeTy* R) { diff --git a/llvm/unittests/ADT/ImmutableSetTest.cpp b/llvm/unittests/ADT/ImmutableSetTest.cpp index c0bde4c4d680b..c85a642d06eb2 100644 --- a/llvm/unittests/ADT/ImmutableSetTest.cpp +++ b/llvm/unittests/ADT/ImmutableSetTest.cpp @@ -164,4 +164,37 @@ TEST_F(ImmutableSetTest, IterLongSetTest) { ASSERT_EQ(6, i); } +TEST_F(ImmutableSetTest, AddIfNotFoundTest) { + ImmutableSet<long>::Factory f(/*canonicalize=*/false); + ImmutableSet<long> S = f.getEmptySet(); + S = f.add(S, 1); + S = f.add(S, 2); + S = f.add(S, 3); + + ImmutableSet<long> T1 = f.add(S, 1); + ImmutableSet<long> T2 = f.add(S, 2); + ImmutableSet<long> T3 = f.add(S, 3); + EXPECT_EQ(S.getRoot(), T1.getRoot()); + EXPECT_EQ(S.getRoot(), T2.getRoot()); + EXPECT_EQ(S.getRoot(), T3.getRoot()); + + ImmutableSet<long> U = f.add(S, 4); + EXPECT_NE(S.getRoot(), U.getRoot()); +} + + +TEST_F(ImmutableSetTest, RemoveIfNotFoundTest) { + ImmutableSet<long>::Factory f(/*canonicalize=*/false); + ImmutableSet<long> S = f.getEmptySet(); + S = f.add(S, 1); + S = f.add(S, 2); + S = f.add(S, 3); + + ImmutableSet<long> T = f.remove(S, 4); + EXPECT_EQ(S.getRoot(), T.getRoot()); + + ImmutableSet<long> U = f.remove(S, 3); + EXPECT_NE(S.getRoot(), U.getRoot()); +} + } `````````` </details> https://github.com/llvm/llvm-project/pull/159845 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
