diff --git a/llvm/lib/Target/RISCV/RISCVInstrFormatsC.td b/llvm/lib/Target/RISCV/RISCVInstrFormatsC.td
--- a/llvm/lib/Target/RISCV/RISCVInstrFormatsC.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrFormatsC.td
@@ -20,8 +20,6 @@
   // to build the decode table.
   field bits<16> SoftFail = 0;
   let Size = 2;
-
-  bits<2> Opcode = 0;
 }
 
 class RVInst16CR<bits<4> funct4, bits<2> opcode, dag outs, dag ins,