[llvm] [CodeGen] Add SSID & Atomic Ordering to IntrinsicInfo (PR #140896)

[Pierre van Houtryve via llvm-commits]

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@@ -5305,9 +5305,16 @@ void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I,
       MPI = MachinePointerInfo(Info.ptrVal, Info.offset);
     else if (Info.fallbackAddressSpace)
       MPI = MachinePointerInfo(*Info.fallbackAddressSpace);
-    Result = DAG.getMemIntrinsicNode(
-        Info.opc, getCurSDLoc(), VTs, Ops, Info.memVT, MPI, Info.align,
-        Info.flags, LocationSize::precise(Info.size), I.getAAMetadata());
+    EVT MemVT = Info.memVT;
+    LocationSize Size = LocationSize::precise(Info.size);
+    if (Size.hasValue() && !Size.getValue())
+      Size = LocationSize::precise(MemVT.getStoreSize());
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Pierre-vh wrote:

This is borrowed from `SelectionDAG::getMemIntrinsicNode`. Without it, I get size mismatches because there is an expectation that the value is initialized if it's zero.

https://github.com/llvm/llvm-project/pull/140896