diff --git a/builtin/builtin.c b/builtin/builtin.c
index 2e66ffb..b0cb579 100644
--- a/builtin/builtin.c
+++ b/builtin/builtin.c
@@ -1,5 +1,6 @@
 #include <string.h>
 #include "../include/share.h"
+#include "../include/SVM_code.h"
 #include "../compiler/summoner.h"
 
 static BasicType sha3_params[] = {HEX_TYPE};
@@ -14,18 +15,30 @@ static BasicType above_params[] = {INT_TYPE, BOOLEAN_TYPE};
 static BasicType lock_params[] = {AMOUNT_TYPE, ASSET_TYPE, HEX_TYPE, HEX_TYPE};
 static BasicType verify_params[] = {BOOLEAN_TYPE};
 
+static SVM_Opcode sha3_ops[] = {OP_SHA3};
+static SVM_Opcode sha256_ops[] = {OP_SHA256};
+static SVM_Opcode abs_ops[] = {OP_ABS};
+static SVM_Opcode min_ops[] = {OP_MIN};
+static SVM_Opcode max_ops[] = {OP_MAX};
+static SVM_Opcode check_tx_sig_ops[] = {OP_TXSIGHASH, OP_SWAP, OP_CHECKSIG};
+static SVM_Opcode check_msg_sig_ops[] = {OP_CHECKSIG};
+static SVM_Opcode below_ops[] = {OP_BLOCKHEIGHT, OP_GREATERTHAN};
+static SVM_Opcode above_ops[] = {OP_BLOCKHEIGHT, OP_LESSTHAN};
+static SVM_Opcode lock_ops[] = {OP_CHECKOUTPUT, OP_VERIFY};
+static SVM_Opcode verify_ops[] = {OP_VERIFY};
+
 BuiltinFun builtin_func_list[] = {
-    {"sha3", sha3_params, ARRAY_SIZE(sha3_params), HASH_TYPE, "SHA3"},
-    {"sha256", sha256_params, ARRAY_SIZE(sha256_params), HASH_TYPE, "SHA256"},
-    {"abs", abs_params, ARRAY_SIZE(abs_params), INT_TYPE, "ABS"},
-    {"min", min_params, ARRAY_SIZE(min_params), INT_TYPE, "MIN"},
-    {"max", max_params, ARRAY_SIZE(max_params), INT_TYPE, "MAX"},
-    {"check_tx_sig", check_tx_sig_params, ARRAY_SIZE(check_tx_sig_params), BOOLEAN_TYPE, "TXSIGHASH SWAP CHECKSIG"},
-    {"check_msg_sig", check_msg_sig_params, ARRAY_SIZE(check_msg_sig_params), BOOLEAN_TYPE, "CHECKSIG"},
-    {"below", below_params, ARRAY_SIZE(below_params), BOOLEAN_TYPE, "BLOCKHEIGHT GREATERTHAN"},
-    {"above", above_params, ARRAY_SIZE(above_params), BOOLEAN_TYPE, "BLOCKHEIGHT LESSTHAN"},
-    {"lock", lock_params, ARRAY_SIZE(lock_params), VOID_TYPE, ""},
-    {"verify", verify_params, ARRAY_SIZE(verify_params), VOID_TYPE, "VERIFY"},
+    {"sha3", sha3_params, ARRAY_SIZE(sha3_params), HASH_TYPE, sha3_ops, ARRAY_SIZE(sha3_ops)},
+    {"sha256", sha256_params, ARRAY_SIZE(sha256_params), HASH_TYPE, sha256_ops, ARRAY_SIZE(sha256_ops)},
+    {"abs", abs_params, ARRAY_SIZE(abs_params), INT_TYPE, abs_ops, ARRAY_SIZE(abs_ops)},
+    {"min", min_params, ARRAY_SIZE(min_params), INT_TYPE, min_ops, ARRAY_SIZE(min_ops)},
+    {"max", max_params, ARRAY_SIZE(max_params), INT_TYPE, max_ops, ARRAY_SIZE(max_ops)},
+    {"check_tx_sig", check_tx_sig_params, ARRAY_SIZE(check_tx_sig_params), BOOLEAN_TYPE, check_tx_sig_ops, ARRAY_SIZE(check_tx_sig_ops)},
+    {"check_msg_sig", check_msg_sig_params, ARRAY_SIZE(check_msg_sig_params), BOOLEAN_TYPE, check_msg_sig_ops, ARRAY_SIZE(check_msg_sig_ops)},
+    {"below", below_params, ARRAY_SIZE(below_params), BOOLEAN_TYPE, below_ops, ARRAY_SIZE(below_ops)},
+    {"above", above_params, ARRAY_SIZE(above_params), BOOLEAN_TYPE, above_ops, ARRAY_SIZE(above_ops)},
+    {"lock", lock_params, ARRAY_SIZE(lock_params), VOID_TYPE, lock_ops, ARRAY_SIZE(lock_ops)},
+    {"verify", verify_params, ARRAY_SIZE(verify_params), VOID_TYPE, verify_ops, ARRAY_SIZE(verify_ops)},
 };
 
 BuiltinFun *search_builtin_function(char *name)
diff --git a/compiler/codegen.c b/compiler/codegen.c
index f399e2a..9c87478 100644
--- a/compiler/codegen.c
+++ b/compiler/codegen.c
@@ -126,6 +126,14 @@ add_global_variable(Compiler *compiler, SVM_Executable *exe)
     }
     // TODO: derive type: FUNCTION_DERIVE/ARRAY_DERIVE
 }
+static void
+generate_builtin_code(OpcodeBuf *ob, SVM_Opcode *ops, int op_cnt)
+{
+    for(int i = 0; i< op_cnt; i++) {
+        ob->code[ob->size] = ops[i];
+        ob->size++;
+    }
+}
 
 static void
 generate_code(OpcodeBuf *ob, SVM_Opcode code,  ...)
@@ -331,6 +339,7 @@ generate_initializer(SVM_Executable *exe, Block *current_block,
                      Declaration *decl_stmt,
                      OpcodeBuf *ob)
 {
+    generate_pop_to_identifier(decl_stmt, ob);
 }
 
 static void
@@ -385,6 +394,9 @@ generate_identifier_expression(SVM_Executable *exe, Block *block,
         break;
     case STRUCT_DEFINITION:
         break;
+    case IDENTIFIER_EXPRESSION:
+        generate_pop_to_lvalue(exe, block, expr, ob);
+        break;
     default:
         printf("bad default. kind..%d", expr->kind);
         exit(1);
@@ -409,8 +421,10 @@ generate_function_call_expression(SVM_Executable *exe, Block *block,
     FuncCallExpression *fce = expr->u.func_call_expression;
     generate_push_argument(exe, block, fce->argument_list, ob);
     generate_expression(exe, block, fce->argument_list->expr, ob);
-    // which op for func call?
-    // generate_code(ob, code);
+
+    BuiltinFun *builtin_fun = expr->u.func_call_expression
+                                ->function->u.identifier->u.builtin_func;
+    generate_builtin_code(ob, builtin_fun->op_codes, builtin_fun->ops_count);
 }
 
 static void
diff --git a/compiler/summoner.h b/compiler/summoner.h
index 9945ee1..2c0cd89 100644
--- a/compiler/summoner.h
+++ b/compiler/summoner.h
@@ -3,6 +3,7 @@
 
 #include <stdbool.h>
 #include <wchar.h>
+#include "../include/SVM_code.h"
 
 typedef enum
 {
@@ -100,7 +101,8 @@ typedef struct BuiltinFun
     BasicType *parameters;
     int parameter_count;
     BasicType return_type;
-    const char *op_codes;
+    SVM_Opcode *op_codes;
+    int ops_count;
 } BuiltinFun;
 
 typedef struct IdentifierExpression