[llvm] [SystemZ] Don't lower float/double ATOMIC_[LOAD|STORE] to [LOAD|STORE] (PR #75879)

[Matt Arsenault via llvm-commits]

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@@ -1545,6 +1552,37 @@ bool SystemZDAGToDAGISel::storeLoadIsAligned(SDNode *N) const {
   return true;
 }
 
+// This is a hack to convert ATOMIC_LOADs to LOADs in the last minute just
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arsenm wrote:

It's also not difficult to use PatFrags between atomic and non-atomic loads instead of hacking this up in C++

https://github.com/llvm/llvm-project/pull/75879