global call-cache cache table for rb_funcall*

rb_funcall* (rb_funcall(), rb_funcallv(), ...) functions invokes
Ruby's method with given receiver. Ruby 2.7 introduced inline method
cache with static memory area. However, Ruby 3.0 reimplemented the
method cache data structures and the inline cache was removed.

Without inline cache, rb_funcall* searched methods everytime.
Most of cases per-Class Method Cache (pCMC) will be helped but
pCMC requires VM-wide locking and it hurts performance on
multi-Ractor execution, especially all Ractors calls methods
with rb_funcall*.

This patch introduced Global Call-Cache Cache Table (gccct) for
rb_funcall*. Call-Cache was introduced from Ruby 3.0 to manage
method cache entry atomically and gccct enables method-caching
without VM-wide locking. This table solves the performance issue
on multi-ractor execution.
[Bug #17497]

Ruby-level method invocation does not use gccct because it has
inline-method-cache and the table size is limited. Basically
rb_funcall* is not used frequently, so 1023 entries can be enough.
We will revisit the table size if it is not enough.

debug_counter.h

@@ -62,6 +62,9 @@ RB_DEBUG_COUNTER(ccs_not_found)  // count for not found corresponding ccs on met
 // vm_eval.c
 RB_DEBUG_COUNTER(call0_public)
 RB_DEBUG_COUNTER(call0_other)
+RB_DEBUG_COUNTER(gccct_hit)
+RB_DEBUG_COUNTER(gccct_miss)
+RB_DEBUG_COUNTER(gccct_null)
 
 // iseq
 RB_DEBUG_COUNTER(iseq_num)    // number of total created iseq

vm.c

@@ -2588,6 +2588,18 @@ rb_vm_mark(void *ptr)
 	rb_gc_mark_values(RUBY_NSIG, vm->trap_list.cmd);
 
         rb_id_table_foreach_values(vm->negative_cme_table, vm_mark_negative_cme, NULL);
+        for (i=0; i<VM_GLOBAL_CC_CACHE_TABLE_SIZE; i++) {
+            const struct rb_callcache *cc = vm->global_cc_cache_table[i];
+
+            if (cc != NULL) {
+                if (!vm_cc_invalidated_p(cc)) {
+                    rb_gc_mark((VALUE)cc);
+                }
+                else {
+                    vm->global_cc_cache_table[i] = NULL;
+                }
+            }
+        }
 
         mjit_mark();
     }

vm_callinfo.h

@@ -386,18 +386,6 @@ extern const struct rb_callcache *rb_vm_empty_cc(void);
 
 /* callcache: mutate */
 
-static inline void
-vm_cc_cme_set(const struct rb_callcache *cc, const struct rb_callable_method_entry_struct *cme)
-{
-    VM_ASSERT(IMEMO_TYPE_P(cc, imemo_callcache));
-    VM_ASSERT(cc != vm_cc_empty());
-    VM_ASSERT(vm_cc_cme(cc) != NULL);
-    VM_ASSERT(vm_cc_cme(cc)->called_id == cme->called_id);
-    VM_ASSERT(!vm_cc_markable(cc)); // only used for vm_eval.c
-
-    *((const struct rb_callable_method_entry_struct **)&cc->cme_) = cme;
-}
-
 static inline void
 vm_cc_call_set(const struct rb_callcache *cc, vm_call_handler call)
 {

vm_core.h

@@ -658,6 +658,11 @@ typedef struct rb_vm_struct {
 
     struct rb_id_table *negative_cme_table;
 
+#ifndef VM_GLOBAL_CC_CACHE_TABLE_SIZE
+#define VM_GLOBAL_CC_CACHE_TABLE_SIZE 1023
+#endif
+    const struct rb_callcache *global_cc_cache_table[VM_GLOBAL_CC_CACHE_TABLE_SIZE]; // vm_eval.c
+
 #if USE_VM_CLOCK
     uint32_t clock;
 #endif

vm_eval.c

@@ -48,7 +48,22 @@ rb_vm_call0(rb_execution_context_t *ec, VALUE recv, ID id, int argc, const VALUE
     struct rb_calling_info calling = {
         .ci = &VM_CI_ON_STACK(id, kw_splat ? VM_CALL_KW_SPLAT : 0, argc, NULL),
         .cc = &VM_CC_ON_STACK(Qfalse, vm_call_general, { 0 }, cme),
-        .block_handler = VM_BLOCK_HANDLER_NONE,
+        .block_handler = vm_passed_block_handler(ec),
+        .recv = recv,
+        .argc = argc,
+        .kw_splat = kw_splat,
+    };
+
+    return vm_call0_body(ec, &calling, argv);
+}
+
+static inline VALUE
+vm_call0_cc(rb_execution_context_t *ec, VALUE recv, ID id, int argc, const VALUE *argv, const struct rb_callcache *cc, int kw_splat)
+{
+    struct rb_calling_info calling = {
+        .ci = &VM_CI_ON_STACK(id, kw_splat ? VM_CALL_KW_SPLAT : 0, argc, NULL),
+        .cc = cc,
+        .block_handler = vm_passed_block_handler(ec),
         .recv = recv,
         .argc = argc,
         .kw_splat = kw_splat,
@@ -57,13 +72,38 @@ rb_vm_call0(rb_execution_context_t *ec, VALUE recv, ID id, int argc, const VALUE
     return vm_call0_body(ec, &calling, argv);
 }
 
+static VALUE
+vm_call0_cme(rb_execution_context_t *ec, struct rb_calling_info *calling, const VALUE *argv, const rb_callable_method_entry_t *cme)
+{
+    calling->cc = &VM_CC_ON_STACK(Qfalse, vm_call_general, { 0 }, cme);
+    return vm_call0_body(ec, calling, argv);
+}
+
+static VALUE
+vm_call0_super(rb_execution_context_t *ec, struct rb_calling_info *calling, const VALUE *argv, VALUE klass, enum method_missing_reason ex)
+{
+    ID mid = vm_ci_mid(calling->ci);
+    klass = RCLASS_SUPER(klass);
+
+    if (klass) {
+        const rb_callable_method_entry_t *cme = rb_callable_method_entry(klass, mid);
+
+        if (cme) {
+            RUBY_VM_CHECK_INTS(ec);
+            return vm_call0_cme(ec, calling, argv, cme);
+        }
+    }
+
+    vm_passed_block_handler_set(ec, calling->block_handler);
+    return method_missing(ec, calling->recv, mid, calling->argc, argv, ex, calling->kw_splat);
+}
+
 static VALUE
 vm_call0_cfunc_with_frame(rb_execution_context_t* ec, struct rb_calling_info *calling, const VALUE *argv)
 {
     const struct rb_callinfo *ci = calling->ci;
-    const struct rb_callcache *cc = calling->cc;
     VALUE val;
-    const rb_callable_method_entry_t *me = vm_cc_cme(cc);
+    const rb_callable_method_entry_t *me = vm_cc_cme(calling->cc);
     const rb_method_cfunc_t *cfunc = UNALIGNED_MEMBER_PTR(me->def, body.cfunc);
     int len = cfunc->argc;
     VALUE recv = calling->recv;
@@ -115,12 +155,8 @@ vm_call0_body(rb_execution_context_t *ec, struct rb_calling_info *calling, const
 {
     const struct rb_callinfo *ci = calling->ci;
     const struct rb_callcache *cc = calling->cc;
-
     VALUE ret;
 
-    calling->block_handler = vm_passed_block_handler(ec);
-
-  again:
     switch (vm_cc_cme(cc)->def->type) {
       case VM_METHOD_TYPE_ISEQ:
 	{
@@ -169,35 +205,24 @@ vm_call0_body(rb_execution_context_t *ec, struct rb_calling_info *calling, const
         ret = vm_call_bmethod_body(ec, calling, argv);
 	goto success;
       case VM_METHOD_TYPE_ZSUPER:
+        {
+            VALUE klass = RCLASS_ORIGIN(vm_cc_cme(cc)->defined_class);
+            return vm_call0_super(ec, calling, argv, klass, MISSING_SUPER);
+        }
       case VM_METHOD_TYPE_REFINED:
 	{
-	    const rb_method_type_t type = vm_cc_cme(cc)->def->type;
+            const rb_callable_method_entry_t *cme = vm_cc_cme(cc);
-	    VALUE super_class = vm_cc_cme(cc)->defined_class;
 
-	    if (type == VM_METHOD_TYPE_ZSUPER) {
+            if (cme->def->body.refined.orig_me) {
-		super_class = RCLASS_ORIGIN(super_class);
+                const rb_callable_method_entry_t *orig_cme = refined_method_callable_without_refinement(cme);
-	    }
+                return vm_call0_cme(ec, calling, argv, orig_cme);
-	    else if (vm_cc_cme(cc)->def->body.refined.orig_me) {
-                vm_cc_cme_set(cc, refined_method_callable_without_refinement(vm_cc_cme(cc)));
-                goto again;
             }
 
-	    super_class = RCLASS_SUPER(super_class);
+            VALUE klass = cme->defined_class;
-            if (super_class) {
+            return vm_call0_super(ec, calling, argv, klass, 0);
-                vm_cc_cme_set(cc, rb_callable_method_entry(super_class, vm_ci_mid(ci)));
-                if (vm_cc_cme(cc)) {
-                    RUBY_VM_CHECK_INTS(ec);
-                    goto again;
-                }
-            }
-
-            enum method_missing_reason ex = (type == VM_METHOD_TYPE_ZSUPER) ? MISSING_SUPER : 0;
-            ret = method_missing(ec, calling->recv, vm_ci_mid(ci), calling->argc, argv, ex, calling->kw_splat);
-            goto success;
 	}
       case VM_METHOD_TYPE_ALIAS:
-        vm_cc_cme_set(cc, aliased_callable_method_entry(vm_cc_cme(cc)));
+        return vm_call0_cme(ec, calling, argv, aliased_callable_method_entry(vm_cc_cme(cc)));
-	goto again;
       case VM_METHOD_TYPE_MISSING:
 	{
             vm_passed_block_handler_set(ec, calling->block_handler);
@@ -312,9 +337,106 @@ rb_check_stack_overflow(void)
     if (ec) stack_check(ec);
 }
 
+NORETURN(static void uncallable_object(VALUE recv, ID mid));
 static inline const rb_callable_method_entry_t *rb_search_method_entry(VALUE recv, ID mid);
 static inline enum method_missing_reason rb_method_call_status(rb_execution_context_t *ec, const rb_callable_method_entry_t *me, call_type scope, VALUE self);
 
+static const struct rb_callcache *
+cc_new(VALUE klass, ID mid, int argc, const rb_callable_method_entry_t *cme)
+{
+    const struct rb_callcache *cc;
+
+    RB_VM_LOCK_ENTER();
+    {
+        struct rb_class_cc_entries *ccs;
+        struct rb_id_table *cc_tbl = RCLASS_CC_TBL(klass);
+
+        if (rb_id_table_lookup(cc_tbl, mid, (VALUE*)&ccs)) {
+            // ok
+        }
+        else {
+            ccs = vm_ccs_create(klass, cme);
+            rb_id_table_insert(cc_tbl, mid, (VALUE)ccs);
+        }
+
+        if (ccs->len > 0) {
+            cc = ccs->entries[0].cc;
+        }
+        else {
+            const struct rb_callinfo *ci = vm_ci_new(mid, 0, argc, false); // TODO: proper ci
+            cc = vm_cc_new(klass, cme, vm_call_general);
+            METHOD_ENTRY_CACHED_SET((struct rb_callable_method_entry_struct *)cme);
+            vm_ccs_push(klass, ccs, ci, cc);
+        }
+    }
+    RB_VM_LOCK_LEAVE();
+
+    return cc;
+}
+
+static VALUE
+gccct_hash(VALUE klass, ID mid)
+{
+    return (klass >> 3) ^ (VALUE)mid;
+}
+
+NOINLINE(static const struct rb_callcache *gccct_method_search_slowpath(rb_vm_t *vm, VALUE klass, ID mid, int argc, unsigned int index));
+
+static const struct rb_callcache *
+gccct_method_search_slowpath(rb_vm_t *vm, VALUE klass, ID mid, int argc, unsigned int index)
+{
+    const rb_callable_method_entry_t *cme = rb_callable_method_entry(klass, mid);
+    const struct rb_callcache *cc;
+
+    if (cme != NULL) {
+        cc = cc_new(klass, mid, argc, cme);
+    }
+    else {
+        cc = NULL;
+    }
+
+    return vm->global_cc_cache_table[index] = cc;
+}
+
+static inline const struct rb_callcache *
+gccct_method_search(rb_execution_context_t *ec, VALUE recv, ID mid, int argc)
+{
+    VALUE klass;
+
+    if (!SPECIAL_CONST_P(recv)) {
+        klass = RBASIC_CLASS(recv);
+        if (UNLIKELY(!klass)) uncallable_object(recv, mid);
+    }
+    else {
+        klass = CLASS_OF(recv);
+    }
+
+    // search global method cache
+    unsigned int index = (unsigned int)(gccct_hash(klass, mid) % VM_GLOBAL_CC_CACHE_TABLE_SIZE);
+    rb_vm_t *vm = rb_ec_vm_ptr(ec);
+    const struct rb_callcache *cc = vm->global_cc_cache_table[index];
+
+    if (LIKELY(cc)) {
+        if (LIKELY(vm_cc_class_check(cc, klass))) {
+            const rb_callable_method_entry_t *cme = vm_cc_cme(cc);
+            if (LIKELY(!METHOD_ENTRY_INVALIDATED(cme) &&
+                       cme->called_id == mid)) {
+
+                VM_ASSERT(vm_cc_cme(cc) == rb_callable_method_entry(klass, mid));
+                RB_DEBUG_COUNTER_INC(gccct_hit);
+
+                return cc;
+            }
+        }
+    }
+    else {
+        RB_DEBUG_COUNTER_INC(gccct_null);
+    }
+
+    RB_DEBUG_COUNTER_INC(gccct_miss);
+    return gccct_method_search_slowpath(vm, klass, mid, argc, index);
+}
+
 /*!
  * \internal
  * calls the specified method.
@@ -336,7 +458,6 @@ rb_call0(rb_execution_context_t *ec,
 	 VALUE recv, ID mid, int argc, const VALUE *argv,
          call_type call_scope, VALUE self)
 {
-    const rb_callable_method_entry_t *me;
     enum method_missing_reason call_status;
     call_type scope = call_scope;
     int kw_splat = RB_NO_KEYWORDS;
@@ -354,21 +475,34 @@ rb_call0(rb_execution_context_t *ec,
         break;
     }
 
+    const struct rb_callcache *cc = gccct_method_search(ec, recv, mid, argc);
+
     if (scope == CALL_PUBLIC) {
         RB_DEBUG_COUNTER_INC(call0_public);
-        me = rb_callable_method_entry_with_refinements(CLASS_OF(recv), mid, NULL);
+
+        const rb_callable_method_entry_t *cc_cme = cc ? vm_cc_cme(cc) : NULL;
+        const rb_callable_method_entry_t *cme = callable_method_entry_refeinements0(CLASS_OF(recv), mid, NULL, true, cc_cme);
+        call_status = rb_method_call_status(ec, cme, scope, self);
+
+        if (UNLIKELY(call_status != MISSING_NONE)) {
+            return method_missing(ec, recv, mid, argc, argv, call_status, kw_splat);
+        }
+        else if (UNLIKELY(cc_cme != cme)) { // refinement is solved
+            stack_check(ec);
+            return rb_vm_call_kw(ec, recv, mid, argc, argv, cme, kw_splat);
+        }
     }
     else {
         RB_DEBUG_COUNTER_INC(call0_other);
-        me = rb_search_method_entry(recv, mid);
+        call_status = rb_method_call_status(ec, cc ? vm_cc_cme(cc) : NULL, scope, self);
-    }
-    call_status = rb_method_call_status(ec, me, scope, self);
 
-    if (call_status != MISSING_NONE) {
+        if (UNLIKELY(call_status != MISSING_NONE)) {
             return method_missing(ec, recv, mid, argc, argv, call_status, kw_splat);
         }
+    }
+
     stack_check(ec);
-    return rb_vm_call_kw(ec, recv, mid, argc, argv, me, kw_splat);
+    return vm_call0_cc(ec, recv, mid, argc, argv, cc, kw_splat);
 }
 
 struct rescue_funcall_args {
@@ -586,7 +720,6 @@ rb_type_str(enum ruby_value_type type)
     return NULL;
 }
 
-NORETURN(static void uncallable_object(VALUE recv, ID mid));
 static void
 uncallable_object(VALUE recv, ID mid)
 {
@@ -860,6 +993,45 @@ method_missing(rb_execution_context_t *ec, VALUE obj, ID id, int argc, const VAL
 
 #ifndef MJIT_HEADER
 
+static inline VALUE
+rb_funcallv_scope(VALUE recv, ID mid, int argc, const VALUE *argv, call_type scope)
+{
+    rb_execution_context_t *ec = GET_EC();
+    const struct rb_callcache *cc = gccct_method_search(ec, recv, mid, argc);
+    VALUE self = ec->cfp->self;
+
+    if (LIKELY(cc) &&
+        LIKELY(rb_method_call_status(ec, vm_cc_cme(cc), scope, self) == MISSING_NONE)) {
+        // fastpath
+        return vm_call0_cc(ec, recv, mid, argc, argv, cc, false);
+    }
+    else {
+        return rb_call0(ec, recv, mid, argc, argv, scope, self);
+    }
+}
+
+#ifdef rb_funcallv
+#undef rb_funcallv
+#endif
+/*!
+ * Calls a method
+ * \param recv   receiver of the method
+ * \param mid    an ID that represents the name of the method
+ * \param argc   the number of arguments
+ * \param argv   pointer to an array of method arguments
+ */
+VALUE
+rb_funcallv(VALUE recv, ID mid, int argc, const VALUE *argv)
+{
+    return rb_funcallv_scope(recv, mid, argc, argv, CALL_FCALL);
+}
+
+VALUE
+rb_funcallv_kw(VALUE recv, ID mid, int argc, const VALUE *argv, int kw_splat)
+{
+    return rb_call(recv, mid, argc, argv, kw_splat ? CALL_FCALL_KW : CALL_FCALL);
+}
+
 /*!
  * Calls a method
  * \param recv   receiver of the method
@@ -885,7 +1057,8 @@ rb_apply(VALUE recv, ID mid, VALUE args)
     }
     argv = ALLOCA_N(VALUE, argc);
     MEMCPY(argv, RARRAY_CONST_PTR_TRANSIENT(args), VALUE, argc);
-    return rb_call(recv, mid, argc, argv, CALL_FCALL);
+
+    return rb_funcallv(recv, mid, argc, argv);
 }
 
 #ifdef rb_funcall
@@ -921,29 +1094,7 @@ rb_funcall(VALUE recv, ID mid, int n, ...)
     else {
 	argv = 0;
     }
-    return rb_call(recv, mid, n, argv, CALL_FCALL);
+    return rb_funcallv(recv, mid, n, argv);
-}
-
-#ifdef rb_funcallv
-#undef rb_funcallv
-#endif
-/*!
- * Calls a method
- * \param recv   receiver of the method
- * \param mid    an ID that represents the name of the method
- * \param argc   the number of arguments
- * \param argv   pointer to an array of method arguments
- */
-VALUE
-rb_funcallv(VALUE recv, ID mid, int argc, const VALUE *argv)
-{
-    return rb_call(recv, mid, argc, argv, CALL_FCALL);
-}
-
-VALUE
-rb_funcallv_kw(VALUE recv, ID mid, int argc, const VALUE *argv, int kw_splat)
-{
-    return rb_call(recv, mid, argc, argv, kw_splat ? CALL_FCALL_KW : CALL_FCALL);
 }
 
 /*!
@@ -973,7 +1124,6 @@ rb_check_funcall_basic_kw(VALUE recv, ID mid, VALUE ancestor, int argc, const VA
     return Qundef;
 }
 
-
 /*!
  * Calls a method.
  *
@@ -986,7 +1136,7 @@ rb_check_funcall_basic_kw(VALUE recv, ID mid, VALUE ancestor, int argc, const VA
 VALUE
 rb_funcallv_public(VALUE recv, ID mid, int argc, const VALUE *argv)
 {
-    return rb_call(recv, mid, argc, argv, CALL_PUBLIC);
+    return rb_funcallv_scope(recv, mid, argc, argv, CALL_PUBLIC);
 }
 
 VALUE
@@ -999,7 +1149,7 @@ VALUE
 rb_funcall_passing_block(VALUE recv, ID mid, int argc, const VALUE *argv)
 {
     PASS_PASSED_BLOCK_HANDLER();
-    return rb_call(recv, mid, argc, argv, CALL_PUBLIC);
+    return rb_funcallv_public(recv, mid, argc, argv);
 }
 
 VALUE
@@ -1016,7 +1166,7 @@ rb_funcall_with_block(VALUE recv, ID mid, int argc, const VALUE *argv, VALUE pas
 	vm_passed_block_handler_set(GET_EC(), passed_procval);
     }
 
-    return rb_call(recv, mid, argc, argv, CALL_PUBLIC);
+    return rb_funcallv_public(recv, mid, argc, argv);
 }
 
 VALUE
@@ -1191,10 +1341,10 @@ VALUE
 rb_yield(VALUE val)
 {
     if (val == Qundef) {
-	return rb_yield_0(0, 0);
+	return rb_yield_0(0, NULL);
     }
     else {
-	return rb_yield_1(val);
+	return rb_yield_0(1, &val);
     }
 }
 

vm_insnhelper.c

@@ -2360,6 +2360,7 @@ vm_callee_setup_arg(rb_execution_context_t *ec, struct rb_calling_info *calling,
 {
     const struct rb_callinfo *ci = calling->ci;
     const struct rb_callcache *cc = calling->cc;
+    bool cacheable_ci = vm_ci_markable(ci);
 
     if (LIKELY(!(vm_ci_flag(ci) & VM_CALL_KW_SPLAT))) {
         if (LIKELY(rb_simple_iseq_p(iseq))) {
@@ -2373,7 +2374,7 @@ vm_callee_setup_arg(rb_execution_context_t *ec, struct rb_calling_info *calling,
 
             VM_ASSERT(ci == calling->ci);
             VM_ASSERT(cc == calling->cc);
-            CC_SET_FASTPATH(cc, vm_call_iseq_setup_func(ci, param_size, local_size), vm_call_iseq_optimizable_p(ci, cc));
+            CC_SET_FASTPATH(cc, vm_call_iseq_setup_func(ci, param_size, local_size), cacheable_ci && vm_call_iseq_optimizable_p(ci, cc));
             return 0;
         }
         else if (rb_iseq_only_optparam_p(iseq)) {
@@ -2393,12 +2394,12 @@ vm_callee_setup_arg(rb_execution_context_t *ec, struct rb_calling_info *calling,
             if (LIKELY(!(vm_ci_flag(ci) & VM_CALL_TAILCALL))) {
                 CC_SET_FASTPATH(cc, vm_call_iseq_setup_normal_opt_start,
                                 !IS_ARGS_SPLAT(ci) && !IS_ARGS_KEYWORD(ci) &&
-                                METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
+                                cacheable_ci && METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
             }
             else {
                 CC_SET_FASTPATH(cc, vm_call_iseq_setup_tailcall_opt_start,
                                 !IS_ARGS_SPLAT(ci) && !IS_ARGS_KEYWORD(ci) &&
-                                METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
+                                cacheable_ci && METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
             }
 
             /* initialize opt vars for self-references */
@@ -2426,7 +2427,7 @@ vm_callee_setup_arg(rb_execution_context_t *ec, struct rb_calling_info *calling,
                     args_setup_kw_parameters(ec, iseq, ci_kws, ci_kw_len, ci_keywords, klocals);
 
                     CC_SET_FASTPATH(cc, vm_call_iseq_setup_kwparm_kwarg,
-                                    METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
+                                    cacheable_ci && METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
 
                     return 0;
                 }
@@ -2439,7 +2440,7 @@ vm_callee_setup_arg(rb_execution_context_t *ec, struct rb_calling_info *calling,
                 if (klocals[kw_param->num] == INT2FIX(0)) {
                     /* copy from default_values */
                     CC_SET_FASTPATH(cc, vm_call_iseq_setup_kwparm_nokwarg,
-                                    METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
+                                    cacheable_ci && METHOD_ENTRY_CACHEABLE(vm_cc_cme(cc)));
                 }
 
                 return 0;

vm_method.c

@@ -1196,11 +1196,10 @@ rb_method_entry_with_refinements(VALUE klass, ID id, VALUE *defined_class_ptr)
 }
 
 static const rb_callable_method_entry_t *
-callable_method_entry_refeinements(VALUE klass, ID id, VALUE *defined_class_ptr, bool with_refinements)
+callable_method_entry_refeinements0(VALUE klass, ID id, VALUE *defined_class_ptr, bool with_refinements,
+                                    const rb_callable_method_entry_t *cme)
 {
-    const rb_callable_method_entry_t *cme = callable_method_entry(klass, id, defined_class_ptr);
+    if (cme == NULL || LIKELY(cme->def->type != VM_METHOD_TYPE_REFINED)) {
-
-    if (cme == NULL || cme->def->type != VM_METHOD_TYPE_REFINED) {
         return cme;
     }
     else {
@@ -1210,6 +1209,13 @@ callable_method_entry_refeinements(VALUE klass, ID id, VALUE *defined_class_ptr,
     }
 }
 
+static const rb_callable_method_entry_t *
+callable_method_entry_refeinements(VALUE klass, ID id, VALUE *defined_class_ptr, bool with_refinements)
+{
+    const rb_callable_method_entry_t *cme = callable_method_entry(klass, id, defined_class_ptr);
+    return callable_method_entry_refeinements0(klass, id, defined_class_ptr, with_refinements, cme);
+}
+
 MJIT_FUNC_EXPORTED const rb_callable_method_entry_t *
 rb_callable_method_entry_with_refinements(VALUE klass, ID id, VALUE *defined_class_ptr)
 {