diff --git a/tcg/tcg.c b/tcg/tcg.c
index c330d114bc..92141bd79a 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -2012,7 +2012,7 @@ static void process_op_defs(TCGContext *s)
     for (op = 0; op < NB_OPS; op++) {
         TCGOpDef *def = &tcg_op_defs[op];
         const TCGTargetOpDef *tdefs;
-        int i, nb_args;
+        int i, o, nb_args;
 
         if (def->flags & TCG_OPF_NOT_PRESENT) {
             continue;
@@ -2034,53 +2034,60 @@ static void process_op_defs(TCGContext *s)
 
         for (i = 0; i < nb_args; i++) {
             const char *ct_str = tdefs->args_ct_str[i];
+            bool input_p = i >= def->nb_oargs;
+
             /* Incomplete TCGTargetOpDef entry. */
             tcg_debug_assert(ct_str != NULL);
 
-            while (*ct_str != '\0') {
-                switch(*ct_str) {
-                case '0' ... '9':
-                    {
-                        int oarg = *ct_str - '0';
-                        tcg_debug_assert(ct_str == tdefs->args_ct_str[i]);
-                        tcg_debug_assert(oarg < def->nb_oargs);
-                        tcg_debug_assert(def->args_ct[oarg].regs != 0);
-                        def->args_ct[i] = def->args_ct[oarg];
-                        /* The output sets oalias.  */
-                        def->args_ct[oarg].oalias = true;
-                        def->args_ct[oarg].alias_index = i;
-                        /* The input sets ialias. */
-                        def->args_ct[i].ialias = true;
-                        def->args_ct[i].alias_index = oarg;
-                    }
-                    ct_str++;
-                    break;
-                case '&':
-                    def->args_ct[i].newreg = true;
-                    ct_str++;
-                    break;
+            switch (*ct_str) {
+            case '0' ... '9':
+                o = *ct_str - '0';
+                tcg_debug_assert(input_p);
+                tcg_debug_assert(o < def->nb_oargs);
+                tcg_debug_assert(def->args_ct[o].regs != 0);
+                tcg_debug_assert(!def->args_ct[o].oalias);
+                def->args_ct[i] = def->args_ct[o];
+                /* The output sets oalias.  */
+                def->args_ct[o].oalias = 1;
+                def->args_ct[o].alias_index = i;
+                /* The input sets ialias. */
+                def->args_ct[i].ialias = 1;
+                def->args_ct[i].alias_index = o;
+                tcg_debug_assert(ct_str[1] == '\0');
+                continue;
+
+            case '&':
+                tcg_debug_assert(!input_p);
+                def->args_ct[i].newreg = true;
+                ct_str++;
+                break;
+            }
+
+            do {
+                switch (*ct_str) {
                 case 'i':
                     def->args_ct[i].ct |= TCG_CT_CONST;
-                    ct_str++;
                     break;
 
                 /* Include all of the target-specific constraints. */
 
 #undef CONST
 #define CONST(CASE, MASK) \
-    case CASE: def->args_ct[i].ct |= MASK; ct_str++; break;
+    case CASE: def->args_ct[i].ct |= MASK; break;
 #define REGS(CASE, MASK) \
-    case CASE: def->args_ct[i].regs |= MASK; ct_str++; break;
+    case CASE: def->args_ct[i].regs |= MASK; break;
 
 #include "tcg-target-con-str.h"
 
 #undef REGS
 #undef CONST
                 default:
+                case '0' ... '9':
+                case '&':
                     /* Typo in TCGTargetOpDef constraint. */
                     g_assert_not_reached();
                 }
-            }
+            } while (*++ct_str != '\0');
         }
 
         /* TCGTargetOpDef entry with too much information? */