[llvm] [AArch64][SME] Allow SME peephole optimizations across SME pseudos (PR #157655)

[Benjamin Maxwell via llvm-commits]

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@@ -184,6 +184,11 @@ bool SMEPeepholeOpt::optimizeStartStopPairs(
           isSVERegOp(TRI, MRI, MI.getOperand(1)))
         Prev = nullptr;
       break;
+    case AArch64::RestoreZAPseudo:
+    case AArch64::InOutZAUsePseudo:
+    case AArch64::CommitZASavePseudo:
+    case AArch64::SMEStateAllocPseudo:
+    case AArch64::RequiresZASavePseudo:
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MacDue wrote:

I've added an explicit check now, but I only intend to allow the `smstart/stop` fold across pairs that only change the streaming mode, not ZA. These pseudos all operate independently of whether or not we're in streaming mode, but may require ZA state.  


https://github.com/llvm/llvm-project/pull/157655