[llvm] [PowerPC] Add a set of extended mnemonics that are missing from Power 10. (PR #73003)

[Amy Kwan via llvm-commits]

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@@ -820,6 +820,27 @@ void PPCAsmParser::ProcessInstruction(MCInst &Inst,
                                       const OperandVector &Operands) {
   int Opcode = Inst.getOpcode();
   switch (Opcode) {
+  case PPC::PLA8:
+  case PPC::PLA: {
+    MCInst TmpInst;
+    TmpInst.setOpcode(PPC::PADDI);
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amy-kwan wrote:

Is this line needed if we are going to end up setting the opcode below on 827 anyway?

https://github.com/llvm/llvm-project/pull/73003