[llvm] [RISCV][AsmParser] Allow parsing vsetvl omitting LMUL parameter (PR #115277)

[Pengcheng Wang via llvm-commits]

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@@ -2222,8 +2222,14 @@ bool RISCVAsmParser::parseVTypeToken(const AsmToken &Tok, VTypeState &State,
     State = VTypeState_LMUL;
     return false;
   case VTypeState_LMUL: {
-    if (!Identifier.consume_front("m"))
-      break;
+    // Set LMUL to default if it is omitted.
+    if (!Identifier.consume_front("m")) {
+      Lmul = 1;
+      Fractional = false;
+      State = VTypeState_TailPolicy;
+      return parseVTypeToken(Tok, State, Sew, Lmul, Fractional, TailAgnostic,
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wangpc-pp wrote:

I think we can just return false here?

https://github.com/llvm/llvm-project/pull/115277