Draft: opt_new instruction

Author: byroot

compile.c

@@ -3930,7 +3930,14 @@ iseq_specialized_instruction(rb_iseq_t *iseq, INSN *iobj)
         }
 
         if ((vm_ci_flag(ci) & VM_CALL_ARGS_BLOCKARG) == 0 && blockiseq == NULL) {
-            iobj->insn_id = BIN(opt_send_without_block);
+            switch (vm_ci_mid(ci)) {
+              case idNew:
+                iobj->insn_id = BIN(opt_new);
+                // TODO: add a second call_data for `#initialize`
+                break;
+              default:
+                iobj->insn_id = BIN(opt_send_without_block);
+            }
             iobj->operand_size = insn_len(iobj->insn_id) - 1;
         }
     }

insns.def

@@ -828,6 +828,37 @@ opt_send_without_block
     }
 }
 
+/* Invoke constructor */
+DEFINE_INSN
+opt_new
+(CALL_DATA cd)
+(...)
+(VALUE val)
+// attr bool handles_sp = true;
+// attr rb_snum_t sp_inc = sp_inc_of_sendish(cd->ci);
+// attr rb_snum_t comptime_sp_inc = sp_inc_of_sendish(ci);
+{
+    VALUE recv = TOPN(vm_ci_argc(cd->ci));
+
+    val = vm_opt_new_alloc(GET_ISEQ(), recv, cd);
+    if (val != Qundef) {
+        fprintf(stderr, "opt!\n");
+        // TODO: call initialize (need a second CALL_DATA).
+    }
+    else {
+        fprintf(stderr, "de-opt!\n");
+    }
+
+    VALUE bh = VM_BLOCK_HANDLER_NONE;
+    val = vm_sendish(ec, GET_CFP(), cd, bh, mexp_search_method);
+    JIT_EXEC(ec, val);
+
+    if (val == Qundef) {
+        RESTORE_REGS();
+        NEXT_INSN();
+    }
+}
+
 /* Convert object to string using to_s or equivalent. */
 DEFINE_INSN
 objtostring

internal/object.h

@@ -21,6 +21,7 @@ int rb_bool_expected(VALUE, const char *, int raise);
 static inline void RBASIC_CLEAR_CLASS(VALUE obj);
 static inline void RBASIC_SET_CLASS_RAW(VALUE obj, VALUE klass);
 static inline void RBASIC_SET_CLASS(VALUE obj, VALUE klass);
+VALUE rb_class_alloc(VALUE klass);
 
 RUBY_SYMBOL_EXPORT_BEGIN
 /* object.c (export) */

object.c

@@ -2063,7 +2063,7 @@ rb_class_alloc_m(VALUE klass)
     return class_call_alloc_func(allocator, klass);
 }
 
-static VALUE
+VALUE
 rb_class_alloc(VALUE klass)
 {
     rb_alloc_func_t allocator = class_get_alloc_func(klass);

vm_insnhelper.c

@@ -6114,6 +6114,15 @@ vm_opt_mod(VALUE recv, VALUE obj)
     }
 }
 
+static VALUE
+vm_opt_new_alloc(const rb_iseq_t *iseq, VALUE recv, CALL_DATA cd)
+{
+    if (RB_TYPE_P(recv, T_CLASS) && vm_method_cfunc_is(iseq, cd, recv, rb_class_new_instance_pass_kw)) {
+        return rb_class_alloc(recv);
+    }
+    return Qundef;
+}
+
 static VALUE
 vm_opt_neq(const rb_iseq_t *iseq, CALL_DATA cd, CALL_DATA cd_eq, VALUE recv, VALUE obj)
 {