[llvm-branch-commits] [llvm] [Support] Recycler: Implement move constructor (PR #120555)

[Akshat Oke via llvm-branch-commits]

https://github.com/optimisan updated https://github.com/llvm/llvm-project/pull/120555

>From 3b1d3fc308754509c5b550ff3677ffaef0343f40 Mon Sep 17 00:00:00 2001
From: Akshat Oke <Akshat.Oke at amd.com>
Date: Thu, 19 Dec 2024 06:57:46 +0000
Subject: [PATCH 1/2] [Support] Recycler: Implement move constructor

---
 llvm/include/llvm/Support/Recycler.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/llvm/include/llvm/Support/Recycler.h b/llvm/include/llvm/Support/Recycler.h
index 8cc882ea5fa058..f105d80563ba93 100644
--- a/llvm/include/llvm/Support/Recycler.h
+++ b/llvm/include/llvm/Support/Recycler.h
@@ -60,6 +60,10 @@ class Recycler {
     // clear() before deleting the Recycler.
     assert(!FreeList && "Non-empty recycler deleted!");
   }
+  Recycler(const Recycler &) = delete;
+  Recycler(Recycler &&Other)
+      : FreeList(std::exchange(Other.FreeList, nullptr)) {}
+  Recycler() = default;
 
   /// clear - Release all the tracked allocations to the allocator. The
   /// recycler must be free of any tracked allocations before being

>From f5baddf0b51d690903af0b37f5280054a19e4c3e Mon Sep 17 00:00:00 2001
From: Akshat Oke <Akshat.Oke at amd.com>
Date: Wed, 1 Jan 2025 06:35:09 +0000
Subject: [PATCH 2/2] Add test

---
 llvm/unittests/Support/RecyclerTest.cpp | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/llvm/unittests/Support/RecyclerTest.cpp b/llvm/unittests/Support/RecyclerTest.cpp
index 8cd763c0b83f8a..0ef9c5aa0ec82b 100644
--- a/llvm/unittests/Support/RecyclerTest.cpp
+++ b/llvm/unittests/Support/RecyclerTest.cpp
@@ -18,6 +18,10 @@ struct Object1 {
   char Data[1];
 };
 
+struct Object8 {
+  char Data[8];
+};
+
 class DecoratedMallocAllocator : public MallocAllocator {
 public:
   int DeallocCount = 0;
@@ -43,4 +47,19 @@ TEST(RecyclerTest, RecycleAllocation) {
   EXPECT_EQ(Allocator.DeallocCount, 2);
 }
 
+TEST(RecyclerTest, MoveConstructor) {
+  DecoratedMallocAllocator Allocator;
+  Recycler<Object8> R;
+  Object8 *A1 = R.Allocate(Allocator);
+  Object8 *A2 = R.Allocate(Allocator);
+  R.Deallocate(Allocator, A1);
+  R.Deallocate(Allocator, A2);
+  Recycler<Object8> R2(std::move(R));
+  Object8 *A3 = R2.Allocate(Allocator);
+  R2.Deallocate(Allocator, A3);
+  R.clear(Allocator); // Should not deallocate anything as it was moved from.
+  EXPECT_EQ(Allocator.DeallocCount, 0);
+  R2.clear(Allocator);
+  EXPECT_EQ(Allocator.DeallocCount, 2);
+}
 } // end anonymous namespace