`vm_call_single_noarg_inline_builtin`

If the iseq only contains `opt_invokebuiltin_delegate_leave` insn and
the builtin-function (bf) is inline-able, the caller doesn't need to
build a method frame.

`vm_call_single_noarg_inline_builtin` is fast path for such cases.

1 files changed, 4 insertions, 0 deletions

diff --git a/compile.c b/compile.c
index e863924397..546c07cec5 100644
--- a/compile.c
+++ b/compile.c
@@ -3646,6 +3646,10 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
         if (IS_TRACE(iobj->link.next)) {
             if (IS_NEXT_INSN_ID(iobj->link.next, leave)) {
                 iobj->insn_id = BIN(opt_invokebuiltin_delegate_leave);
+                const struct rb_builtin_function *bf = (const struct rb_builtin_function *)iobj->operands[0];
+                if (iobj == (INSN *)list && bf->argc == 0 && (iseq->body->builtin_attrs & BUILTIN_ATTR_LEAF)) {
+                    iseq->body->builtin_attrs |= BUILTIN_ATTR_SINGLE_NOARG_INLINE;
+                }
             }
         }
     }