revert r65213 and r65215

as we didn't agree on the actual implementation yet

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65222 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

tool/ruby_vm/views/_mjit_compile_ivar.erb

@@ -15,7 +15,7 @@
 % end
 %
 % # compiler: Consider cfp->self as T_OBJECT if ic->ic_serial is set
-    if (ic->ic_serial >= RUBY_VM_CLASS_SERIAL_MIN_VALID_VALUE) {
+    if (ic->ic_serial) {
 % # JIT: optimize away motion of sp and pc. This path does not call rb_warning() and so it's always leaf and not `handles_sp`.
 % # <%= render 'mjit_compile_pc_and_sp', locals: { insn: insn } -%>
 %

vm.c

@@ -340,7 +340,7 @@ rb_event_flag_t ruby_vm_event_flags;
 rb_event_flag_t ruby_vm_event_enabled_flags;
 rb_serial_t ruby_vm_global_method_state = 1;
 rb_serial_t ruby_vm_global_constant_state = 1;
-rb_serial_t ruby_vm_class_serial = RUBY_VM_CLASS_SERIAL_MIN_VALID_VALUE;
+rb_serial_t ruby_vm_class_serial = 1;
 
 static void thread_free(void *ptr);
 

vm_core.h

@@ -1846,9 +1846,4 @@ void rb_postponed_job_flush(rb_vm_t *vm);
 
 RUBY_SYMBOL_EXPORT_END
 
-/* special values for ruby_vm_class_serial */
-#define RUBY_VM_CLASS_SERIAL_UNSET 0 /* Not cached yet. Fields in `is_entries` and `cc_entries` start from 0 due to ZALLOC_N. */
-#define RUBY_VM_CLASS_SERIAL_INVALID 1 /* Cache invalidated and never cached again. */
-#define RUBY_VM_CLASS_SERIAL_MIN_VALID_VALUE 2 /* Actual class serials are larger than this value. */
-
 #endif /* RUBY_VM_CORE_H */

vm_insnhelper.c

@@ -976,21 +976,13 @@ vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, int is_attr)
 		    if (index < ROBJECT_NUMIV(obj)) {
 			val = ROBJECT_IVPTR(obj)[index];
 		    }
-                    if (!is_attr) { /* getinstancevariable */
-                        if (ic->ic_serial == RUBY_VM_CLASS_SERIAL_UNSET) {
-                            /* set ic_serial only for the first time */
-                            ic->ic_value.index = index;
-                            ic->ic_serial = RCLASS_SERIAL(RBASIC(obj)->klass);
-                        }
-                        else if (ic->ic_serial != RUBY_VM_CLASS_SERIAL_INVALID) {
-                            /* never use cache for another class, to avoid race condition with MJIT worker
-                               and to reduce the number of JIT cancellations by code generated for IC hit. */
-                            ic->ic_serial = RUBY_VM_CLASS_SERIAL_INVALID;
-                        }
-                    }
-                    else { /* call_info */
-                        cc->aux.index = (int)index + 1;
-                    }
+		    if (!is_attr) {
+			ic->ic_value.index = index;
+			ic->ic_serial = RCLASS_SERIAL(RBASIC(obj)->klass);
+		    }
+		    else { /* call_info */
+			cc->aux.index = (int)index + 1;
+		    }
 		}
 	    }
 	}
@@ -1039,18 +1031,10 @@ vm_setivar(VALUE obj, ID id, VALUE val, IC ic, struct rb_call_cache *cc, int is_
 	    struct st_table *iv_index_tbl = ROBJECT_IV_INDEX_TBL(obj);
 
 	    if (iv_index_tbl && st_lookup(iv_index_tbl, (st_data_t)id, &index)) {
-                if (!is_attr) { /* setinstancevariable */
-                    if (ic->ic_serial == RUBY_VM_CLASS_SERIAL_UNSET) {
-                        /* set ic_serial only for the first time */
-                        ic->ic_value.index = index;
-                        ic->ic_serial = RCLASS_SERIAL(klass);
-                    }
-                    else if (ic->ic_serial != RUBY_VM_CLASS_SERIAL_INVALID) {
-                        /* never use cache for another class, to avoid race condition with MJIT worker
-                           and to reduce the number of JIT cancellations by code generated for IC hit. */
-                        ic->ic_serial = RUBY_VM_CLASS_SERIAL_INVALID;
-                    }
-                }
+		if (!is_attr) {
+		    ic->ic_value.index = index;
+		    ic->ic_serial = RCLASS_SERIAL(klass);
+		}
 		else if (index >= INT_MAX) {
 		    rb_raise(rb_eArgError, "too many instance variables");
 		}