add INVALID tag for abstract frame

Author: cocolato

Include/internal/pycore_optimizer.h

@@ -115,8 +115,10 @@ static inline uint16_t uop_get_error_target(const _PyUOpInstruction *inst)
 
 
 #define REF_IS_BORROWED 1
+#define REF_IS_INVALID  2
+#define REF_TAG_BITS    3
 
-#define JIT_BITS_TO_PTR_MASKED(REF) ((JitOptSymbol *)(((REF).bits) & (~REF_IS_BORROWED)))
+#define JIT_BITS_TO_PTR_MASKED(REF) ((JitOptSymbol *)(((REF).bits) & (~REF_TAG_BITS)))
 
 static inline JitOptSymbol *
 PyJitRef_Unwrap(JitOptRef ref)
@@ -133,6 +135,18 @@ PyJitRef_Wrap(JitOptSymbol *sym)
     return (JitOptRef){.bits=(uintptr_t)sym};
 }
 
+static inline JitOptRef
+PyJitRef_WrapInvalid(void *ptr)
+{
+    return (JitOptRef){.bits=(uintptr_t)ptr | REF_IS_INVALID};
+}
+
+static inline bool
+PyJitRef_IsInvalid(JitOptRef ref)
+{
+    return (ref.bits & REF_IS_INVALID) == REF_IS_INVALID;
+}
+
 static inline JitOptRef
 PyJitRef_StripReferenceInfo(JitOptRef ref)
 {

Include/internal/pycore_optimizer_types.h

@@ -40,7 +40,6 @@ 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 {
@@ -93,7 +92,6 @@ 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_bytecodes.c

@@ -340,7 +340,7 @@ dummy_func(void) {
         }
         f->locals[0] = container;
         f->locals[1] = sub;
-        new_frame = PyJitRef_Wrap((JitOptSymbol *)f);
+        new_frame = PyJitRef_WrapInvalid(f);
     }
 
     op(_BINARY_OP_SUBSCR_STR_INT, (str_st, sub_st -- res, s, i)) {
@@ -784,7 +784,7 @@ dummy_func(void) {
             break;
         }
         f->locals[0] = owner;
-        new_frame = PyJitRef_Wrap((JitOptSymbol *)f);
+        new_frame = PyJitRef_WrapInvalid(f);
     }
 
     op(_INIT_CALL_BOUND_METHOD_EXACT_ARGS, (callable, self_or_null, unused[oparg] -- callable, self_or_null, unused[oparg])) {
@@ -848,9 +848,9 @@ dummy_func(void) {
         }
 
         if (sym_is_null(self_or_null) || sym_is_not_null(self_or_null)) {
-            new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, args, argcount));
+            new_frame = PyJitRef_WrapInvalid(frame_new(ctx, co, 0, args, argcount));
         } else {
-            new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
+            new_frame = PyJitRef_WrapInvalid(frame_new(ctx, co, 0, NULL, 0));
         }
     }
 
@@ -868,7 +868,7 @@ dummy_func(void) {
             break;
         }
 
-        new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
+        new_frame = PyJitRef_WrapInvalid(frame_new(ctx, co, 0, NULL, 0));
     }
 
     op(_PY_FRAME_KW, (callable, self_or_null, args[oparg], kwnames -- new_frame)) {
@@ -879,7 +879,7 @@ dummy_func(void) {
             break;
         }
 
-        new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
+        new_frame = PyJitRef_WrapInvalid(frame_new(ctx, co, 0, NULL, 0));
     }
 
     op(_PY_FRAME_EX, (func_st, null, callargs_st, kwargs_st -- ex_frame)) {
@@ -890,7 +890,7 @@ dummy_func(void) {
             break;
         }
 
-        ex_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
+        ex_frame = PyJitRef_WrapInvalid(frame_new(ctx, co, 0, NULL, 0));
     }
 
     op(_CHECK_AND_ALLOCATE_OBJECT, (type_version/2, callable, self_or_null, args[oparg] -- callable, self_or_null, args[oparg])) {
@@ -914,7 +914,7 @@ dummy_func(void) {
         ctx->curr_frame_depth++;
         assert((this_instr + 1)->opcode == _PUSH_FRAME);
         PyCodeObject *co = get_code_with_logging((this_instr + 1));
-        init_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, args-1, oparg+1));
+        init_frame = PyJitRef_WrapInvalid(frame_new(ctx, co, 0, args-1, oparg+1));
     }
 
     op(_RETURN_VALUE, (retval -- res)) {
@@ -1007,7 +1007,7 @@ dummy_func(void) {
             break;
         }
         new_frame->stack[0] = sym_new_const(ctx, Py_None);
-        gen_frame = PyJitRef_Wrap((JitOptSymbol *)new_frame);
+        gen_frame = PyJitRef_WrapInvalid(new_frame);
     }
 
     op(_SEND_GEN_FRAME, (unused, v -- unused, gen_frame)) {
@@ -1023,7 +1023,7 @@ dummy_func(void) {
             break;
         }
         new_frame->stack[0] = PyJitRef_StripReferenceInfo(v);
-        gen_frame = PyJitRef_Wrap((JitOptSymbol *)new_frame);
+        gen_frame = PyJitRef_WrapInvalid(new_frame);
     }
 
     op(_CHECK_STACK_SPACE, (unused, unused, unused[oparg] -- unused, unused, unused[oparg])) {

Python/optimizer_cases.c.h

@@ -76,6 +76,10 @@ _PyUOpSymPrint(JitOptRef ref)
         printf("<JitRef NULL>");
         return;
     }
+    if (PyJitRef_IsInvalid(ref)) {
+        printf("<INVALID frame at %p>", (void *)PyJitRef_Unwrap(ref));
+        return;
+    }
     JitOptSymbol *sym = PyJitRef_Unwrap(ref);
     switch (sym->tag) {
         case JIT_SYM_UNKNOWN_TAG:
@@ -109,9 +113,6 @@ _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;
@@ -874,7 +875,6 @@ _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;