diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index d430ea10c8..a6310b898f 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -518,6 +518,11 @@ typedef struct TCGOp {
 /* Make sure operands fit in the bitfields above.  */
 QEMU_BUILD_BUG_ON(NB_OPS > (1 << 8));
 
+static inline TCGRegSet output_pref(const TCGOp *op, unsigned i)
+{
+    return i < ARRAY_SIZE(op->output_pref) ? op->output_pref[i] : 0;
+}
+
 typedef struct TCGProfile {
     int64_t cpu_exec_time;
     int64_t tb_count1;
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 52261417b8..65be472fef 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1957,7 +1957,7 @@ static void tcg_dump_ops(TCGContext *s, FILE *f, bool have_prefs)
 
         if (have_prefs) {
             for (i = 0; i < nb_oargs; ++i) {
-                TCGRegSet set = op->output_pref[i];
+                TCGRegSet set = output_pref(op, i);
 
                 if (i == 0) {
                     ne_fprintf(f, "  pref=");
@@ -2627,11 +2627,11 @@ static void liveness_pass_1(TCGContext *s)
                     }
                     ts->state = TS_DEAD;
                     la_reset_pref(ts);
-
-                    /* Not used -- it will be tcg_target_call_oarg_regs[i].  */
-                    op->output_pref[i] = 0;
                 }
 
+                /* Not used -- it will be tcg_target_call_oarg_reg().  */
+                memset(op->output_pref, 0, sizeof(op->output_pref));
+
                 if (!(call_flags & (TCG_CALL_NO_WRITE_GLOBALS |
                                     TCG_CALL_NO_READ_GLOBALS))) {
                     la_global_kill(s, nb_globals);
@@ -2793,7 +2793,9 @@ static void liveness_pass_1(TCGContext *s)
                 ts = arg_temp(op->args[i]);
 
                 /* Remember the preference of the uses that followed.  */
-                op->output_pref[i] = *la_temp_pref(ts);
+                if (i < ARRAY_SIZE(op->output_pref)) {
+                    op->output_pref[i] = *la_temp_pref(ts);
+                }
 
                 /* Output args are dead.  */
                 if (ts->state & TS_DEAD) {
@@ -2863,7 +2865,7 @@ static void liveness_pass_1(TCGContext *s)
 
                     set &= ct->regs;
                     if (ct->ialias) {
-                        set &= op->output_pref[ct->alias_index];
+                        set &= output_pref(op, ct->alias_index);
                     }
                     /* If the combination is not possible, restart.  */
                     if (set == 0) {
@@ -3581,7 +3583,7 @@ static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op)
     TCGType otype, itype;
 
     allocated_regs = s->reserved_regs;
-    preferred_regs = op->output_pref[0];
+    preferred_regs = output_pref(op, 0);
     ots = arg_temp(op->args[0]);
     ts = arg_temp(op->args[1]);
 
@@ -3696,7 +3698,7 @@ static void tcg_reg_alloc_dup(TCGContext *s, const TCGOp *op)
         if (IS_DEAD_ARG(1)) {
             temp_dead(s, its);
         }
-        tcg_reg_alloc_do_movi(s, ots, val, arg_life, op->output_pref[0]);
+        tcg_reg_alloc_do_movi(s, ots, val, arg_life, output_pref(op, 0));
         return;
     }
 
@@ -3712,7 +3714,7 @@ static void tcg_reg_alloc_dup(TCGContext *s, const TCGOp *op)
             tcg_regset_set_reg(allocated_regs, its->reg);
         }
         ots->reg = tcg_reg_alloc(s, dup_out_regs, allocated_regs,
-                                 op->output_pref[0], ots->indirect_base);
+                                 output_pref(op, 0), ots->indirect_base);
         ots->val_type = TEMP_VAL_REG;
         ots->mem_coherent = 0;
         s->reg_to_temp[ots->reg] = ots;
@@ -3831,7 +3833,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
         switch (arg_ct->pair) {
         case 0: /* not paired */
             if (arg_ct->ialias) {
-                i_preferred_regs = op->output_pref[arg_ct->alias_index];
+                i_preferred_regs = output_pref(op, arg_ct->alias_index);
 
                 /*
                  * If the input is readonly, then it cannot also be an
@@ -3882,7 +3884,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
             ts2 = i1 != i2 ? arg_temp(op->args[i2]) : NULL;
 
             if (arg_ct->ialias) {
-                i_preferred_regs = op->output_pref[arg_ct->alias_index];
+                i_preferred_regs = output_pref(op, arg_ct->alias_index);
                 if (IS_DEAD_ARG(i1) &&
                     IS_DEAD_ARG(i2) &&
                     !temp_readonly(ts) &&
@@ -3928,7 +3930,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
 
         case 3: /* ialias with second output, no first input */
             tcg_debug_assert(arg_ct->ialias);
-            i_preferred_regs = op->output_pref[arg_ct->alias_index];
+            i_preferred_regs = output_pref(op, arg_ct->alias_index);
 
             allocate_new_reg = true;
             if (IS_DEAD_ARG(i) &&
@@ -4018,10 +4020,10 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
                 } else if (arg_ct->newreg) {
                     reg = tcg_reg_alloc(s, arg_ct->regs,
                                         i_allocated_regs | o_allocated_regs,
-                                        op->output_pref[k], ts->indirect_base);
+                                        output_pref(op, k), ts->indirect_base);
                 } else {
                     reg = tcg_reg_alloc(s, arg_ct->regs, o_allocated_regs,
-                                        op->output_pref[k], ts->indirect_base);
+                                        output_pref(op, k), ts->indirect_base);
                 }
                 break;
 
@@ -4032,7 +4034,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
                     break;
                 }
                 reg = tcg_reg_alloc_pair(s, arg_ct->regs, o_allocated_regs,
-                                         op->output_pref[k], ts->indirect_base);
+                                         output_pref(op, k), ts->indirect_base);
                 break;
 
             case 2: /* second of pair */
@@ -4123,7 +4125,7 @@ static bool tcg_reg_alloc_dup2(TCGContext *s, const TCGOp *op)
         }
 
         ots->reg = tcg_reg_alloc(s, dup_out_regs, allocated_regs,
-                                 op->output_pref[0], ots->indirect_base);
+                                 output_pref(op, 0), ots->indirect_base);
         ots->val_type = TEMP_VAL_REG;
         ots->mem_coherent = 0;
         s->reg_to_temp[ots->reg] = ots;
