diff --git a/tcg/optimize.c b/tcg/optimize.c
index 74b9aa025a..77cdffaaef 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -675,7 +675,6 @@ void tcg_optimize(TCGContext *s)
 
     QTAILQ_FOREACH_SAFE(op, &s->ops, link, op_next) {
         uint64_t z_mask, partmask, affected, tmp;
-        int nb_oargs, nb_iargs;
         TCGOpcode opc = op->opc;
         const TCGOpDef *def;
 
@@ -686,10 +685,8 @@ void tcg_optimize(TCGContext *s)
         }
 
         def = &tcg_op_defs[opc];
-        nb_oargs = def->nb_oargs;
-        nb_iargs = def->nb_iargs;
-        init_arguments(&ctx, op, nb_oargs + nb_iargs);
-        copy_propagate(&ctx, op, nb_oargs, nb_iargs);
+        init_arguments(&ctx, op, def->nb_oargs + def->nb_iargs);
+        copy_propagate(&ctx, op, def->nb_oargs, def->nb_iargs);
 
         /* For commutative operations make constant second argument */
         switch (opc) {
@@ -1063,7 +1060,7 @@ void tcg_optimize(TCGContext *s)
 
         CASE_OP_32_64(qemu_ld):
             {
-                MemOpIdx oi = op->args[nb_oargs + nb_iargs];
+                MemOpIdx oi = op->args[def->nb_oargs + def->nb_iargs];
                 MemOp mop = get_memop(oi);
                 if (!(mop & MO_SIGN)) {
                     z_mask = (2ULL << ((8 << (mop & MO_SIZE)) - 1)) - 1;
@@ -1122,12 +1119,10 @@ void tcg_optimize(TCGContext *s)
         }
 
         if (partmask == 0) {
-            tcg_debug_assert(nb_oargs == 1);
             tcg_opt_gen_movi(&ctx, op, op->args[0], 0);
             continue;
         }
         if (affected == 0) {
-            tcg_debug_assert(nb_oargs == 1);
             tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[1]);
             continue;
         }
@@ -1202,7 +1197,6 @@ void tcg_optimize(TCGContext *s)
             } else if (args_are_copies(op->args[1], op->args[2])) {
                 op->opc = INDEX_op_dup_vec;
                 TCGOP_VECE(op) = MO_32;
-                nb_iargs = 1;
             }
             break;
 
@@ -1371,7 +1365,6 @@ void tcg_optimize(TCGContext *s)
                 op->opc = opc = (opc == INDEX_op_movcond_i32
                                  ? INDEX_op_setcond_i32
                                  : INDEX_op_setcond_i64);
-                nb_iargs = 2;
             }
             break;
 
@@ -1579,6 +1572,7 @@ void tcg_optimize(TCGContext *s)
         if (def->flags & TCG_OPF_BB_END) {
             memset(&ctx.temps_used, 0, sizeof(ctx.temps_used));
         } else {
+            int nb_oargs = def->nb_oargs;
             for (i = 0; i < nb_oargs; i++) {
                 reset_temp(op->args[i]);
                 /* Save the corresponding known-zero bits mask for the