[llvm] [Exegesis][RISCV] Add initial RVV support (PR #128767)

[Min-Yih Hsu via llvm-commits]

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@@ -35,6 +35,19 @@ const ExegesisTarget *ExegesisTarget::lookup(Triple TT) {
   return nullptr;
 }
 
+const char *
+ExegesisTarget::getIgnoredOpcodeReasonOrNull(const LLVMState &State,
+                                             unsigned Opcode) const {
+  const MCInstrDesc &InstrDesc = State.getIC().getInstr(Opcode).Description;
+  if (InstrDesc.isPseudo() || InstrDesc.usesCustomInsertionHook())
+    return "Unsupported opcode: isPseudo/usesCustomInserter";
+  if (InstrDesc.isBranch() || InstrDesc.isIndirectBranch())
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mshockwave wrote:

> What's causing those to be ignored today?

I don't think JAL and JALR are explicitly ignored. If anything, the snippets for these two opcodes will just crash silently (with a message shown in the result, of course) inside the sandbox built by JIT without affecting other snippets. 

https://github.com/llvm/llvm-project/pull/128767