From 592288a50bb4218179cbdd135c00714f8db8e403 Mon Sep 17 00:00:00 2001
From: Tobias Stadler <mail@stadler-tobias.de>
Date: Tue, 6 Aug 2024 17:34:47 +0200
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20change?=
 =?UTF-8?q?s=20to=20main=20this=20commit=20is=20based=20on?=
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Created using spr 1.3.6-bogner-wip

[skip ci]
---
 .../llvm/CodeGen/GlobalISel/GISelChangeObserver.h   |  3 +++
 .../include/llvm/CodeGen/GlobalISel/GISelWorkList.h |  2 +-
 llvm/lib/CodeGen/GlobalISel/Combiner.cpp            | 13 +++++++------
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h b/llvm/include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h
index cad2216db34fe..7ec5dac9a6eba 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h
@@ -79,6 +79,9 @@ class GISelObserverWrapper : public MachineFunction::Delegate,
     if (It != Observers.end())
       Observers.erase(It);
   }
+  // Removes all observers
+  void clearObservers() { Observers.clear(); }
+
   // API for Observer.
   void erasingInstr(MachineInstr &MI) override {
     for (auto &O : Observers)
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/GISelWorkList.h b/llvm/include/llvm/CodeGen/GlobalISel/GISelWorkList.h
index 3ec6a1da201e2..dba3a8a14480c 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/GISelWorkList.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/GISelWorkList.h
@@ -82,7 +82,7 @@ class GISelWorkList {
   /// Remove I from the worklist if it exists.
   void remove(const MachineInstr *I) {
 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
-    assert((Finalized || WorklistMap.empty()) && "Neither finalized nor empty");
+    assert(Finalized && "GISelWorkList used without finalizing");
 #endif
     auto It = WorklistMap.find(I);
     if (It == WorklistMap.end())
diff --git a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
index 3310ce5455c97..49842e5fd65da 100644
--- a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
@@ -110,11 +110,6 @@ Combiner::Combiner(MachineFunction &MF, CombinerInfo &CInfo,
   if (CSEInfo)
     B.setCSEInfo(CSEInfo);
 
-  // Setup observer.
-  ObserverWrapper->addObserver(WLObserver.get());
-  if (CSEInfo)
-    ObserverWrapper->addObserver(CSEInfo);
-
   B.setChangeObserver(*ObserverWrapper);
 }
 
@@ -147,13 +142,16 @@ bool Combiner::combineMachineInstrs() {
     LLVM_DEBUG(dbgs() << "\n\nCombiner iteration #" << Iteration << '\n');
 
     WorkList.clear();
+    ObserverWrapper->clearObservers();
+    if (CSEInfo)
+      ObserverWrapper->addObserver(CSEInfo);
 
     // Collect all instructions. Do a post order traversal for basic blocks and
     // insert with list bottom up, so while we pop_back_val, we'll traverse top
     // down RPOT.
     Changed = false;
 
-    RAIIDelegateInstaller DelInstall(MF, ObserverWrapper.get());
+    RAIIMFObsDelInstaller DelInstall(MF, *ObserverWrapper);
     for (MachineBasicBlock *MBB : post_order(&MF)) {
       for (MachineInstr &CurMI :
            llvm::make_early_inc_range(llvm::reverse(*MBB))) {
@@ -168,6 +166,9 @@ bool Combiner::combineMachineInstrs() {
       }
     }
     WorkList.finalize();
+
+    // Only notify WLObserver during actual combines
+    ObserverWrapper->addObserver(WLObserver.get());
     // Main Loop. Process the instructions here.
     while (!WorkList.empty()) {
       MachineInstr *CurrInst = WorkList.pop_back_val();