[llvm] [LAA] Catch load/store to invariant address in dependency checker. (PR #187023)

[Ramkumar Ramachandra via llvm-commits]

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@@ -2833,6 +2844,25 @@ bool LoopAccessInfo::analyzeLoop(AAResults *AA, const LoopInfo *LI,
     }
   }
 
+  // Update the invariant address dependence flags based on dependences found
+  // by the dep checker. Even if dependences were not recorded (too many to
+  // track), any InvariantUnsafe dep would still have set the status to Unsafe
+  if (const auto *Deps = DepChecker->getDependences()) {
+    for (const auto &Dep : *Deps) {
+      if (Dep.Type != MemoryDepChecker::Dependence::InvariantUnsafe)
+        continue;
+      Instruction *Src = Dep.getSource(*DepChecker);
+      Instruction *Dst = Dep.getDestination(*DepChecker);
+      if (isa<LoadInst>(Src) != isa<LoadInst>(Dst))
+        HasLoadStoreDependenceInvolvingLoopInvariantAddress = true;
+      else {
+        assert(isa<StoreInst>(Src) && isa<StoreInst>(Dst) &&
+               "Expected both to be stores");
+        HasStoreStoreDependenceInvolvingLoopInvariantAddress = true;
+      }
+    }
+  }
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artagnon wrote:

It would be nice if we could unify this code with code above that sets the two variables as @lukel97 also mentioned, but if you want to do it as a follow-up, could you add a TODO/FIXME here?

https://github.com/llvm/llvm-project/pull/187023