[PATCH] D130225: [Attributor] Check for noalias call in AAInstanceInfo

[Nikita Popov via Phabricator via llvm-commits]

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TBH I don't really understand what this code is doing, but going just by naming, it seems like the relevant property of allocation functions of interest here is their uniqueness (in the sense of disjoint provenance), which is encoded by the `noalias` return attribute. Or does this rely on some other property of allocators as well?


https://reviews.llvm.org/D130225

Files:
  llvm/lib/Transforms/IPO/AttributorAttributes.cpp


Index: llvm/lib/Transforms/IPO/AttributorAttributes.cpp
===================================================================
--- llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -4825,11 +4825,8 @@
     auto EquivalentUseCB = [&](const Use &OldU, const Use &NewU) {
       if (auto *SI = dyn_cast<StoreInst>(OldU.getUser())) {
         auto *Ptr = SI->getPointerOperand()->stripPointerCasts();
-        if (isa<AllocaInst>(Ptr) && AA::isDynamicallyUnique(A, *this, *Ptr))
-          return true;
-        auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(
-            *SI->getFunction());
-        if (isAllocationFn(Ptr, TLI) && AA::isDynamicallyUnique(A, *this, *Ptr))
+        if ((isa<AllocaInst>(Ptr) || isNoAliasCall(Ptr)) &&
+            AA::isDynamicallyUnique(A, *this, *Ptr))
           return true;
       }
       return false;


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