diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 6f3ab7aa52..77f794ed70 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -34,9 +34,13 @@
 %imm_u    12:s20                 !function=ex_shift_12
 
 # Argument sets:
+&empty
 &b    imm rs2 rs1
 &i    imm rs1 rd
+&j    imm rd
 &r    rd rs1 rs2
+&s    imm rs1 rs2
+&u    imm rd
 &shift     shamt rs1 rd
 &atomic    aq rl rs2 rs1 rd
 
@@ -44,9 +48,9 @@
 @r       .......   ..... ..... ... ..... ....... &r                %rs2 %rs1 %rd
 @i       ............    ..... ... ..... ....... &i      imm=%imm_i     %rs1 %rd
 @b       .......   ..... ..... ... ..... ....... &b      imm=%imm_b %rs2 %rs1
-@s       .......   ..... ..... ... ..... .......         imm=%imm_s %rs2 %rs1
-@u       ....................      ..... .......         imm=%imm_u          %rd
-@j       ....................      ..... .......         imm=%imm_j          %rd
+@s       .......   ..... ..... ... ..... ....... &s      imm=%imm_s %rs2 %rs1
+@u       ....................      ..... ....... &u      imm=%imm_u          %rd
+@j       ....................      ..... ....... &j      imm=%imm_j          %rd
 
 @sh      ......  ...... .....  ... ..... ....... &shift  shamt=%sh10      %rs1 %rd
 @csr     ............   .....  ... ..... .......               %csr     %rs1 %rd
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 840ecbef36..928374242e 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -687,11 +687,29 @@ static bool gen_shift(DisasContext *ctx, arg_r *a,
 #include "insn_trans/trans_rvd.inc.c"
 #include "insn_trans/trans_privileged.inc.c"
 
+/*
+ * Auto-generated decoder.
+ * Note that the 16-bit decoder reuses some of the trans_* functions
+ * initially declared by the 32-bit decoder, which results in duplicate
+ * declaration warnings.  Suppress them.
+ */
+#ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wredundant-decls"
+# ifdef __clang__
+#  pragma GCC diagnostic ignored "-Wtypedef-redefinition"
+# endif
+#endif
+
 bool decode_insn16(DisasContext *ctx, uint16_t insn);
 /* auto-generated decoder*/
 #include "decode_insn16.inc.c"
 #include "insn_trans/trans_rvc.inc.c"
 
+#ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
+# pragma GCC diagnostic pop
+#endif
+
 static void decode_opc(DisasContext *ctx)
 {
     /* check for compressed insn */