[CodeGen] LiveRegMatrix: Use allocator through a unique_ptr

[optimisan]

LIU::Matrix holds on to a pointer to the allocator in LiveRegMatrix and is left hanging when the allocator moves with the LiveRegMatrix.

This extends the lifetime of the allocator so that it does not get destroyed when moving a LiveRegMatrix object.

[optimisan]

• [Support] Recycler: Implement move constructor #120555 : 2 dependent PRs (#117309 , #121889 )
• [Support] Recycler: Enforce minimum allocation size #121425
• [CodeGen] LiveRegMatrix: Use allocator through a unique_ptr #120556 👈 (View in Graphite)
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[llvmbot]

@llvm/pr-subscribers-llvm-regalloc

Author: Akshat Oke (optimisan)

Changes

LIU::Matrix holds on to a pointer to the allocator in LiveRegMatrix and is left hanging when the allocator moves with the LiveRegMatrix.

This extends the lifetime of the allocator so that it does not get destroyed when moving a LiveRegMatrix object.

---

Full diff: https://github.com/llvm/llvm-project/pull/120556.diff

2 Files Affected:

• (modified) llvm/include/llvm/CodeGen/LiveRegMatrix.h (+3-7)
• (modified) llvm/lib/CodeGen/LiveRegMatrix.cpp (+1-1)

diff --git a/llvm/include/llvm/CodeGen/LiveRegMatrix.h b/llvm/include/llvm/CodeGen/LiveRegMatrix.h
index 486392ca3c49d5..a7c1e2bcfe1c43 100644
--- a/llvm/include/llvm/CodeGen/LiveRegMatrix.h
+++ b/llvm/include/llvm/CodeGen/LiveRegMatrix.h
@@ -48,7 +48,7 @@ class LiveRegMatrix {
   unsigned UserTag = 0;
 
   // The matrix is represented as a LiveIntervalUnion per register unit.
-  LiveIntervalUnion::Allocator LIUAlloc;
+  std::unique_ptr<LiveIntervalUnion::Allocator> LIUAlloc;
   LiveIntervalUnion::Array Matrix;
 
   // Cached queries per register unit.
@@ -59,15 +59,11 @@ class LiveRegMatrix {
   unsigned RegMaskVirtReg = 0;
   BitVector RegMaskUsable;
 
-  LiveRegMatrix() = default;
+  LiveRegMatrix() : LIUAlloc(new LiveIntervalUnion::Allocator()) {};
   void releaseMemory();
 
 public:
-  LiveRegMatrix(LiveRegMatrix &&Other)
-      : TRI(Other.TRI), LIS(Other.LIS), VRM(Other.VRM), UserTag(Other.UserTag),
-        Matrix(std::move(Other.Matrix)), Queries(std::move(Other.Queries)),
-        RegMaskTag(Other.RegMaskTag), RegMaskVirtReg(Other.RegMaskVirtReg),
-        RegMaskUsable(std::move(Other.RegMaskUsable)) {}
+  LiveRegMatrix(LiveRegMatrix &&Other) = default;
 
   void init(MachineFunction &MF, LiveIntervals &LIS, VirtRegMap &VRM);
 
diff --git a/llvm/lib/CodeGen/LiveRegMatrix.cpp b/llvm/lib/CodeGen/LiveRegMatrix.cpp
index 9744c47d5a8510..3367171a15662f 100644
--- a/llvm/lib/CodeGen/LiveRegMatrix.cpp
+++ b/llvm/lib/CodeGen/LiveRegMatrix.cpp
@@ -66,7 +66,7 @@ void LiveRegMatrix::init(MachineFunction &MF, LiveIntervals &pLIS,
   unsigned NumRegUnits = TRI->getNumRegUnits();
   if (NumRegUnits != Matrix.size())
     Queries.reset(new LiveIntervalUnion::Query[NumRegUnits]);
-  Matrix.init(LIUAlloc, NumRegUnits);
+  Matrix.init(*LIUAlloc, NumRegUnits);
 
   // Make sure no stale queries get reused.
   invalidateVirtRegs();

[mtrofin]

nit: could also do LIUAlloc(std::make_unique<LiveIntervalUnion::Allocator>) up to you.

[optimisan]

Merge activity

• Jan 1, 4:22 AM EST: A user started a stack merge that includes this pull request via Graphite.
• Jan 1, 4:24 AM EST: A user merged this pull request with Graphite.