diff --git a/llvm/lib/Target/RISCV/RISCVInstrFormats.td b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
--- a/llvm/lib/Target/RISCV/RISCVInstrFormats.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
@@ -162,7 +162,7 @@
 
   dag OutOperandList = outs;
   dag InOperandList = ins;
-  let AsmString = opcodestr # "\t" # argstr;
+  let AsmString = !if(!empty(argstr), opcodestr, opcodestr # "\t" # argstr);
   let Pattern = pattern;
 
   let TSFlags{4-0} = format.Value;