[llvm] [DebugInfo] Handle additional types of stores in assignment tracking (PR #129070)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -2123,6 +2183,25 @@ getUntaggedStoreAssignmentInfo(const Instruction &I, const DataLayout &Layout) {
   return std::nullopt;
 }
 
+AllocaInst *getUnknownStore(const Instruction &I, const DataLayout &Layout) {
+  auto *II = dyn_cast<IntrinsicInst>(&I);
+  if (!II)
+    return nullptr;
+  Intrinsic::ID ID = II->getIntrinsicID();
+  if (ID != Intrinsic::experimental_vp_strided_store &&
+      ID != Intrinsic::masked_store && ID != Intrinsic::vp_scatter &&
+      ID != Intrinsic::masked_scatter && ID != Intrinsic::vp_store)
+    return nullptr;
+  Value *MemOp = II->getArgOperand(1);
+  // We don't actually use the constant offset for now, but we may in future,
+  // and the non-accumulating versions do not support a vector of pointers.
+  APInt Offset(Layout.getIndexTypeSizeInBits(MemOp->getType()), 0);
+  Value *Base = MemOp->stripAndAccumulateConstantOffsets(Layout, Offset, true);
+  // For Base pointers that are not an alloca instruction we don't need to do
+  // anything, and simply return nullptr.
+  return dyn_cast<AllocaInst>(Base);
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OCHyams wrote:

Could a `vp_scatter` store to multiple different allocas? My question is basically whether it's a given that we can return a _single_ "base" pointer for any given scatter?

https://github.com/llvm/llvm-project/pull/129070