[llvm] [LICM] Improve LICM when calls only change Inaccessible memory (PR #169379)

[Matt Arsenault via llvm-commits]

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@@ -277,6 +277,17 @@ static bool areLoadsReorderable(const LoadInst *Use,
   return !(SeqCstUse || MayClobberIsAcquire);
 }
 
+bool hasInaccessibleMemoryClobber(const CallBase *CallFirst,
+                                  const CallBase *CallSecond) {
+
+  MemoryEffects ME1 = CallFirst->getMemoryEffects();
+  MemoryEffects ME2 = CallSecond->getMemoryEffects();
+  if (CallFirst->onlyAccessesInaccessibleMemory() ||
+      CallSecond->onlyAccessesInaccessibleMemory())
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arsenm wrote:

Isn't onlyAccessesInaccessibleMemory implemented in terms of MemoryEffects? Can you keep all of this in terms of MemoryEffects? 

https://github.com/llvm/llvm-project/pull/169379