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

[Jonas Paulsson 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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JonPsson1 wrote:

Well, with all the different extending load operators it is not quite simple I'd say, but of course better. My concern is that if the ATOMIC_LOAD opcode will go away those changes would have to be reverted again in the .td files. So if that might happen in some foreseeable future, maybe this hack would be acceptable? As an alternative, maybe the switch to PatFrags could be done as a follow-up patch so that it could more easily be reverted if needed..?

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