[llvm] 6db73fa - [SandboxVec][Scheduler] Fix clear() to clear all state (#124214)

[via llvm-commits]

Author: vporpo
Date: 2025-01-23T21:27:53-08:00
New Revision: 6db73fa481beb9184ea8f1103e72e7a5c1d82e31

URL: https://github.com/llvm/llvm-project/commit/6db73fa481beb9184ea8f1103e72e7a5c1d82e31
DIFF: https://github.com/llvm/llvm-project/commit/6db73fa481beb9184ea8f1103e72e7a5c1d82e31.diff

LOG: [SandboxVec][Scheduler] Fix clear() to clear all state (#124214)

This patch fixes the scheduler's clear() function to also clear the
ReadyList. Not doing so is a bug and results in crashes when the
ReadyList contains stale instructions, because it was never clered.

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.h
    llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Scheduler.h

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.h b/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.h
index 00b53b42e2e572..b2d7c9b8aa8bbc 100644
--- a/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.h
+++ b/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.h
@@ -417,6 +417,13 @@ class DependencyGraph {
     DAGInterval = {};
   }
 #ifndef NDEBUG
+  /// \Returns true if the DAG's state is clear. Used in assertions.
+  bool empty() const {
+    bool IsEmpty = InstrToNodeMap.empty();
+    assert(IsEmpty == DAGInterval.empty() &&
+           "Interval and InstrToNodeMap out of sync!");
+    return IsEmpty;
+  }
   void print(raw_ostream &OS) const;
   LLVM_DUMP_METHOD void dump() const;
 #endif // NDEBUG

diff  --git a/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Scheduler.h b/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Scheduler.h
index 52891c3f7535c9..25432e1396c73f 100644
--- a/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Scheduler.h
+++ b/llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Scheduler.h
@@ -164,7 +164,10 @@ class Scheduler {
     Bndls.clear();
     // TODO: clear view once it lands.
     DAG.clear();
+    ReadyList.clear();
     ScheduleTopItOpt = std::nullopt;
+    assert(Bndls.empty() && DAG.empty() && ReadyList.empty() &&
+           !ScheduleTopItOpt && "Expected empty state!");
   }
 
 #ifndef NDEBUG