add INVALID_TAG for abstract frame

Author: cocolato

Include/internal/pycore_optimizer_types.h

@@ -39,6 +39,8 @@ typedef enum _JitSymType {
     JIT_SYM_TUPLE_TAG = 8,
     JIT_SYM_TRUTHINESS_TAG = 9,
     JIT_SYM_COMPACT_INT = 10,
+ 
+    JIT_SYM_INVALID_TAG = 255, // for non-symbol values on abstract stack
 } JitSymType;
 
 typedef struct _jit_opt_known_class {
@@ -91,6 +93,7 @@ typedef union {
 } JitOptRef;
 
 typedef struct _Py_UOpsAbstractFrame {
+    uint8_t tag;
     bool globals_watched;
     // The version number of the globals dicts, once checked. 0 if unchecked.
     uint32_t globals_checked_version;

Python/optimizer_symbols.c

@@ -109,6 +109,9 @@ _PyUOpSymPrint(JitOptRef ref)
         case JIT_SYM_COMPACT_INT:
             printf("<compact_int at %p>", (void *)sym);
             break;
+        case JIT_SYM_INVALID_TAG:
+            printf("<INVALID frame at %p>", (void *)sym);
+            break;
         default:
             printf("<tag=%d at %p>", sym->tag, (void *)sym);
             break;
@@ -871,6 +874,7 @@ _Py_uop_frame_new(
         return NULL;
     }
     _Py_UOpsAbstractFrame *frame = &ctx->frames[ctx->curr_frame_depth];
+    frame->tag = JIT_SYM_INVALID_TAG;
     frame->code = co;
     frame->stack_len = co->co_stacksize;
     frame->locals_len = co->co_nlocalsplus;