[PATCH] D133303: [DebugInfo] Fix minor debug info bug in deleteDeadLoop

[Orlando Cazalet-Hyams via Phabricator via llvm-commits]

Orlando created this revision.
Orlando added reviewers: StephenTozer, jryans, djtodoro.
Orlando added a project: debug-info.
Herald added a subscriber: hiraditya.
Herald added a project: All.
Orlando requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Using a `DebugVariable` as the set key rather than `std::pair<DIVariable *, DIExpression *>` ensures we don't accidently confuse multiple instances of inlined variables.

I just noticed this while in the area and don't have a test case, but I could probably hand-write one if necessary.


https://reviews.llvm.org/D133303

Files:
  llvm/lib/Transforms/Utils/LoopUtils.cpp


Index: llvm/lib/Transforms/Utils/LoopUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -598,7 +598,7 @@
   }
 
   // Use a map to unique and a vector to guarantee deterministic ordering.
-  llvm::SmallDenseSet<std::pair<DIVariable *, DIExpression *>, 4> DeadDebugSet;
+  llvm::SmallDenseSet<DebugVariable, 4> DeadDebugSet;
   llvm::SmallVector<DbgVariableIntrinsic *, 4> DeadDebugInst;
 
   if (ExitBlock) {
@@ -627,11 +627,8 @@
         auto *DVI = dyn_cast<DbgVariableIntrinsic>(&I);
         if (!DVI)
           continue;
-        auto Key =
-            DeadDebugSet.find({DVI->getVariable(), DVI->getExpression()});
-        if (Key != DeadDebugSet.end())
+        if (!DeadDebugSet.insert(DebugVariable(DVI)).second)
           continue;
-        DeadDebugSet.insert({DVI->getVariable(), DVI->getExpression()});
         DeadDebugInst.push_back(DVI);
       }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D133303.457992.patch
Type: text/x-patch
Size: 988 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220905/4799a209/attachment.bin>