[llvm] [SelectionDAG] Make the FoldingSet profile in getAtomic match AddNodeIDCustom. (PR #136651)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

The code in AddNodeIDCustom:

const AtomicSDNode *AT = cast<AtomicSDNode>(N);
ID.AddInteger(AT->getMemoryVT().getRawBits());
ID.AddInteger(AT->getRawSubclassData());
ID.AddInteger(AT->getPointerInfo().getAddrSpace()); ID.AddInteger(AT->getMemOperand()->getFlags());

In theory, the mismatch would have made CSE of AtomicSDNodes not work, but I don't know how to test it.

---
Full diff: https://github.com/llvm/llvm-project/pull/136651.diff


1 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (+3-1) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index ba6c5d884d381..5269962ea2062 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -8994,8 +8994,10 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT,
                                 SDVTList VTList, ArrayRef<SDValue> Ops,
                                 MachineMemOperand *MMO) {
   FoldingSetNodeID ID;
-  ID.AddInteger(MemVT.getRawBits());
   AddNodeIDNode(ID, Opcode, VTList, Ops);
+  ID.AddInteger(MemVT.getRawBits());
+  ID.AddInteger(getSyntheticNodeSubclassData<AtomicSDNode>(
+      Opcode, dl.getIROrder(), VTList, MemVT, MMO));
   ID.AddInteger(MMO->getPointerInfo().getAddrSpace());
   ID.AddInteger(MMO->getFlags());
   void* IP = nullptr;

``````````

</details>


https://github.com/llvm/llvm-project/pull/136651