diff --git a/README.md b/README.md
index 8af9ccb..edffdb5 100644
--- a/README.md
+++ b/README.md
@@ -674,10 +674,21 @@ dylib.dlclose(dlhandle);
 
 `dylib.dlsym` is used to get the function address.
 
-`dylib.dlcall` is used to call the function, the first argument is the function address, make sure this argument is vm_obj and type=obj_extern.
+`dylib.dlcall` is used to call the function, the first argument is the function address, make sure this argument is `vm_obj` and `type=obj_extern`.
 
 `dylib.dlclose` is used to unload the library, at the moment that you call the function, all the function addresses that got from it are invalid.
 
+`dylib.limitcall` is used to get `dlcall` function that has limited parameter size, this function will prove the performance of your code because it does not use `vm_vec` to store the arguments, instead it uses local scope to store them, so this could avoid frequently garbage collecting. And the code above could also be written like this:
+
+```javascript
+var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+var fib=dylib.dlsym(dlhandle,"fib");
+var invoke=dylib.limitcall(1); # this means the called function has only one parameter
+for(var i=1;i<30;i+=1)
+    println(invoke(fib,i));
+dylib.dlclose(dlhandle);
+```
+
 If get this, Congratulations!
 
 ```bash
diff --git a/doc/README_zh.md b/doc/README_zh.md
index a4c154a..4a4624c 100644
--- a/doc/README_zh.md
+++ b/doc/README_zh.md
@@ -647,10 +647,21 @@ dylib.dlclose(dlhandle);
 
 `dylib.dlsym`通过符号从动态库中获得函数地址。
 
-`dylib.dlcall`用于调用函数，第一个参数是动态库函数的地址，这是个特殊类型，一定要保证这个参数是vm_obj类型并且type=obj_extern。
+`dylib.dlcall`用于调用函数，第一个参数是动态库函数的地址，这是个特殊类型，一定要保证这个参数是`vm_obj`类型并且`type=obj_extern`。
 
 `dylib.dlclose`用于卸载动态库，当然，在这个函数调用之后，所有从该库中获取的函数都作废。
 
+`dylib.limitcall`用于获取使用固定长度传参的 `dlcall` 函数，这种函数可以提高你的程序运行效率，因为它不需要用 `vm_vec` 来存储传入参数，而是使用局部作用域来直接存储，从而避免了频繁调用可能导致的频繁垃圾收集。所以上面展示的代码同样可以这样写：
+
+```javascript
+var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+var fib=dylib.dlsym(dlhandle,"fib");
+var invoke=dylib.limitcall(1); # 这说明我们要调用的函数只有一个参数
+for(var i=1;i<30;i+=1)
+    println(invoke(fib,i));
+dylib.dlclose(dlhandle);
+```
+
 如果接下来你看到了这个运行结果，恭喜你！
 
 ```bash
diff --git a/lib.nas b/lib.nas
index 0a9db19..e8e0785 100644
--- a/lib.nas
+++ b/lib.nas
@@ -280,8 +280,7 @@ var md5=func(str){
     return __md5(str);
 }
 
-var io=
-{
+var io={
     SEEK_SET:0,
     SEEK_CUR:1,
     SEEK_END:2,
@@ -333,8 +332,7 @@ var fstat=func(filename){
 
 # functions that do bitwise calculation.
 # carefully use it, all the calculations are based on integer.
-var bits=
-{
+var bits={
     # i32 xor
     i32_xor: func(a,b){return __i32xor(a,b); },
     # i32 and
@@ -378,8 +376,7 @@ var bits=
 };
 
 # mostly used math functions and special constants, you know.
-var math=
-{
+var math={
     e:     2.7182818284590452354,
     pi:    3.14159265358979323846264338327950288,
     D2R:   2.7182818284590452354/180,
@@ -402,8 +399,7 @@ var math=
     min:   func(x,y){return x<y?x:y;     }
 };
 
-var unix=
-{
+var unix={
     pipe:     func(){return __pipe;},
     fork:     func(){return __fork;},
     dup2:     func(fd0,fd1){die("not supported yet");},
@@ -425,8 +421,7 @@ var unix=
 
 # dylib is the core hashmap for developers to load their own library.
 # for safe using dynamic library, you could use 'module' in stl/module.nas
-var dylib=
-{
+var dylib={
     # open dynamic lib.
     dlopen:  func(libname){
         # find dynamic lib from local dir first
@@ -451,22 +446,34 @@ var dylib=
     dlsym:   func(lib,sym){return __dlsym; },
     # close dynamic lib, this operation will make all the symbols loaded from it invalid.
     dlclose: func(lib){return __dlclose;   },
-    # call the loaded symbol.
-    dlcall:  func(ptr,args...){return __dlcall}
+    # call the loaded symbol, with infinite parameters:
+    # Caution: this may cause garbage collection process, be aware of the performance.
+    dlcall:  func(ptr,args...){return __dlcallv},
+    # get dlcall function with limited parameter list
+    limitcall: func(arg_size=0){
+        if(arg_size==0){return func(ptr){return __dlcall};}
+        else if(arg_size==1){return func(ptr,_0){return __dlcall};}
+        else if(arg_size==2){return func(ptr,_0,_1){return __dlcall};}
+        else if(arg_size==3){return func(ptr,_0,_1,_2){return __dlcall};}
+        else if(arg_size==4){return func(ptr,_0,_1,_2,_3){return __dlcall};}
+        else if(arg_size==5){return func(ptr,_0,_1,_2,_3,_4){return __dlcall};}
+        else if(arg_size==6){return func(ptr,_0,_1,_2,_3,_4,_5){return __dlcall};}
+        else if(arg_size==7){return func(ptr,_0,_1,_2,_3,_4,_5,_6){return __dlcall};}
+        else if(arg_size==8){return func(ptr,_0,_1,_2,_3,_4,_5,_6,_7){return __dlcall};}
+        else{return func(ptr,args...){return __dlcallv};}
+    }
 };
 
 # os is used to use or get some os-related info/functions.
 # windows/macOS/linux are supported.
-var os=
-{
+var os={
     # get a string that tell which os it runs on.
     platform: func(){return __platform;},
     time:     func(){return __logtime; }
 };
 
 # runtime gives us some functions that we could manage it manually.
-var runtime=
-{
+var runtime={
     # command line arguments
     argv: func(){return __sysargv;}
 };
diff --git a/module/fib.cpp b/module/fib.cpp
index cdac2ff..c4a3771 100644
--- a/module/fib.cpp
+++ b/module/fib.cpp
@@ -8,26 +8,20 @@ double fibonaci(double x){
 }
 
 var fib(var* args,usize size,gc* ngc){
-    std::cout<<"[mod] this is the first test module of nasal\n";
     if(!size)
         return nas_err("fib","lack arguments");
     var num=args[0];
-    if(num.type!=vm_num)
-        return nas_err("extern_fib","\"num\" must be number");
     return {vm_num,fibonaci(num.tonum())};
 }
 
 var quick_fib(var* args,usize size,gc* ngc){
-    std::cout<<"[mod] this is the first test module of nasal\n";
     if(!size)
-        return nas_err("fib","lack arguments");
-    var num=args[0];
-    if(num.type!=vm_num)
-        return nas_err("extern_quick_fib","\"num\" must be number");
-    if(num.num()<2)
-        return num;
+        return nas_err("quick_fib","lack arguments");
+    double num=args[0].tonum();
+    if(num<2)
+        return {vm_num,num};
     double a=1,b=1,res=0;
-    for(double i=1;i<num.num();i+=1){
+    for(double i=1;i<num;i+=1){
         res=a+b;
         a=b;
         b=res;
diff --git a/module/libfib.nas b/module/libfib.nas
index 07f6d63..064bcf4 100644
--- a/module/libfib.nas
+++ b/module/libfib.nas
@@ -2,7 +2,7 @@ var libfib=func(){
     var dl=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
     var fib=dylib.dlsym(dl,"fib");
     var qfib=dylib.dlsym(dl,"quick_fib");
-    var call=dylib.dlcall;
+    var call=dylib.limitcall(1);
     return {
         fib: func(x){return call(fib,x)},
         qfib:func(x){return call(qfib,x)}
diff --git a/module/libkey.nas b/module/libkey.nas
index 114799a..f08073e 100644
--- a/module/libkey.nas
+++ b/module/libkey.nas
@@ -3,7 +3,7 @@ var libkey=func(){
     var kb=dylib.dlsym(lib,"nas_kbhit");
     var gt=dylib.dlsym(lib,"nas_getch");
     var nb=dylib.dlsym(lib,"nas_noblock");
-    var call=dylib.dlcall;
+    var call=dylib.limitcall(0);
     return {
         kbhit:func(){return call(kb);},
         getch:func(){return call(gt);},
diff --git a/module/libmat.nas b/module/libmat.nas
index f82a1f4..e557551 100644
--- a/module/libmat.nas
+++ b/module/libmat.nas
@@ -27,32 +27,36 @@ var libmat=func(){
         dylib.dlsym(dl,"nas_rotate_y"),
         dylib.dlsym(dl,"nas_rotate_z")
     );
-    var call=dylib.dlcall;
+    var (invoke_i,invoke_ii,invoke_iii)=(
+        dylib.limitcall(1),
+        dylib.limitcall(2),
+        dylib.limitcall(3)
+    );
     return {
         vec2:{
-            new:func(x,y){return call(vec2,x,y);},
-            add:func(v0,v1){return call(vec2add,v0,v1);},
-            sub:func(v0,v1){return call(vec2sub,v0,v1);},
-            mul:func(v0,v1){return call(vec2mul,v0,v1);},
-            div:func(v0,v1){return call(vec2div,v0,v1);},
-            neg:func(v0){return call(vec2neg,v0);},
-            norm:func(v0){return call(vec2norm,v0);},
-            len:func(v0){return call(vec2len,v0);},
-            dot:func(v0,v1){return call(vec2dot,v0,v1);}
+            new:  func(x,y){return invoke_ii(vec2,x,y);},
+            add:  func(v0,v1){return invoke_ii(vec2add,v0,v1);},
+            sub:  func(v0,v1){return invoke_ii(vec2sub,v0,v1);},
+            mul:  func(v0,v1){return invoke_ii(vec2mul,v0,v1);},
+            div:  func(v0,v1){return invoke_ii(vec2div,v0,v1);},
+            neg:  func(v0){return invoke_i(vec2neg,v0);},
+            norm: func(v0){return invoke_i(vec2norm,v0);},
+            len:  func(v0){return invoke_i(vec2len,v0);},
+            dot:  func(v0,v1){return invoke_ii(vec2dot,v0,v1);}
         },
         vec3:{
-            new:func(x,y,z){return call(vec3,x,y,z);},
-            add:func(v0,v1){return call(vec3add,v0,v1);},
-            sub:func(v0,v1){return call(vec3sub,v0,v1);},
-            mul:func(v0,v1){return call(vec3mul,v0,v1);},
-            div:func(v0,v1){return call(vec3div,v0,v1);},
-            neg:func(v0){return call(vec3neg,v0);},
-            norm:func(v0){return call(vec3norm,v0);},
-            len:func(v0){return call(vec3len,v0);},
-            rx:func(v0,angle){return call(rotate_x,v0,angle);},
-            ry:func(v0,angle){return call(rotate_y,v0,angle);},
-            rz:func(v0,angle){return call(rotate_z,v0,angle);},
-            dot:func(v0,v1){return call(vec3dot,v0,v1);}
+            new:  func(x,y,z){return invoke_iii(vec3,x,y,z);},
+            add:  func(v0,v1){return invoke_ii(vec3add,v0,v1);},
+            sub:  func(v0,v1){return invoke_ii(vec3sub,v0,v1);},
+            mul:  func(v0,v1){return invoke_ii(vec3mul,v0,v1);},
+            div:  func(v0,v1){return invoke_ii(vec3div,v0,v1);},
+            neg:  func(v0){return invoke_i(vec3neg,v0);},
+            norm: func(v0){return invoke_i(vec3norm,v0);},
+            len:  func(v0){return invoke_i(vec3len,v0);},
+            rx:   func(v0,angle){return invoke_ii(rotate_x,v0,angle);},
+            ry:   func(v0,angle){return invoke_ii(rotate_y,v0,angle);},
+            rz:   func(v0,angle){return invoke_ii(rotate_z,v0,angle);},
+            dot:  func(v0,v1){return invoke_ii(vec3dot,v0,v1);}
         }
     };
 }();
\ No newline at end of file
diff --git a/module/libsock.nas b/module/libsock.nas
index e187fce..2c9d28e 100644
--- a/module/libsock.nas
+++ b/module/libsock.nas
@@ -1,5 +1,6 @@
 var socket=func(){
     var lib=dylib.dlopen("libnasock"~(os.platform()=="windows"?".dll":".so"));
+    
     var sock=dylib.dlsym(lib,"nas_socket");
     var closesocket=dylib.dlsym(lib,"nas_closesocket");
     var shutdown=dylib.dlsym(lib,"nas_shutdown");
@@ -12,17 +13,46 @@ var socket=func(){
     var recv=dylib.dlsym(lib,"nas_recv");
     var recvfrom=dylib.dlsym(lib,"nas_recvfrom");
     var errno=dylib.dlsym(lib,"nas_errno");
-    var call=dylib.dlcall;
+
+    var (invoke,invoke_i,invoke_ii,invoke_iii,invoke_iiii,invoke_iiiii)=(
+        dylib.limitcall(0),
+        dylib.limitcall(1),
+        dylib.limitcall(2),
+        dylib.limitcall(3),
+        dylib.limitcall(4),
+        dylib.limitcall(5),
+    );
     return {
-        AF_UNSPEC:0,AF_UNIX:1,AF_INET:2,AF_IMPLINK:3,
-        AF_PUP:4,AF_CHAOS:5,AF_IPX:6,AF_NS:6,
-        AF_ISO:7,AF_OSI:7,AF_ECMA:8,AF_DATAKIT:9,
-        AF_CCITT:10,AF_SNA:11,AF_DECnet:12,AF_DLI:13,
-        AF_LAT:14,AF_HYLINK:15,AF_APPLETALK:16,AF_NETBIOS:17,
-        AF_VOICEVIEW:18,AF_FIREFOX:19,AF_UNKNOWN1:20,AF_BAN:21,
+        AF_UNSPEC:0,
+        AF_UNIX:1,
+        AF_INET:2,
+        AF_IMPLINK:3,
+        AF_PUP:4,
+        AF_CHAOS:5,
+        AF_IPX:6,
+        AF_NS:6,
+        AF_ISO:7,
+        AF_OSI:7,
+        AF_ECMA:8,
+        AF_DATAKIT:9,
+        AF_CCITT:10,
+        AF_SNA:11,
+        AF_DECnet:12,
+        AF_DLI:13,
+        AF_LAT:14,
+        AF_HYLINK:15,
+        AF_APPLETALK:16,
+        AF_NETBIOS:17,
+        AF_VOICEVIEW:18,
+        AF_FIREFOX:19,
+        AF_UNKNOWN1:20,
+        AF_BAN:21,
         AF_MAX:22,
 
-        SOCK_STREAM:1,SOCK_DGRAM:2,SOCK_RAW:3,SOCK_RDM:4,
+        SOCK_STREAM:1,
+        SOCK_DGRAM:2,
+        SOCK_RAW:3,
+        SOCK_RDM:4,
         SOCK_SEQPACKET:5,
 
         IPPROTO_IP:0,IPPROTO_ICMP:1,IPPROTO_IGMP:2,IPPROTO_GGP:3,
@@ -46,40 +76,40 @@ var socket=func(){
         MSG_DONTROUTE:0x4,
 
         socket:func(af,type,proto){
-            return call(sock,af,type,proto);
+            return invoke_iii(sock,af,type,proto);
         },
         closesocket:func(sd){
-            return call(closesocket,sd);
+            return invoke_i(closesocket,sd);
         },
         shutdown: func(sd,how){
-            return call(shutdown,sd,how);
+            return invoke_ii(shutdown,sd,how);
         },
         bind: func(sd,ip,port){
-            return call(bind,sd,ip,port);
+            return invoke_iii(bind,sd,ip,port);
         },
         listen: func(sd,backlog){
-            return call(listen,sd,backlog);
+            return invoke_ii(listen,sd,backlog);
         },
         connect: func(sd,hostname,port){
-            return call(connect,sd,hostname,port);
+            return invoke_iii(connect,sd,hostname,port);
         },
         accept: func(sd){
-            return call(accept,sd);
+            return invoke_i(accept,sd);
         },
         send: func(sd,buff,flags=0){
-            return call(send,sd,buff,flags);
+            return invoke_iii(send,sd,buff,flags);
         },
         sendto: func(sd,hostname,port,buff,flags=0){
-            return call(sendto,sd,hostname,port,buff,flags);
+            return invoke_iiiii(sendto,sd,hostname,port,buff,flags);
         },
         recv: func(sd,len,flags=0){
-            return call(recv,sd,len,flags);
+            return invoke_iii(recv,sd,len,flags);
         },
         recvfrom: func(sd,len,flags=0){
-            return call(recvfrom,sd,len,flags);
+            return invoke_iii(recvfrom,sd,len,flags);
         },
         errno: func(){
-            return call(errno);
+            return invoke(errno);
         }
     };
 }();
\ No newline at end of file
diff --git a/module/makefile b/module/makefile
index 0b78959..189c653 100644
--- a/module/makefile
+++ b/module/makefile
@@ -5,6 +5,11 @@ dynamic_libs_dll=libfib.dll libkey.dll libnasock.dll libmat.dll
 
 STD=c++14
 
+all: $(dynamic_libs_so)
+	@ echo "[Compiling] done"
+winall: $(dynamic_libs_dll)
+	@ echo [Compiling] done
+
 libfib.so: fib.cpp
 	@ echo "[Compiling] libfib.so"
 	@ $(CXX) -std=$(STD) -c -O3 fib.cpp -fPIC -o fib.o
@@ -54,8 +59,3 @@ clean:
 	-@ rm $(dynamic_libs_so)
 	@ echo "[clean] dll"
 	-@ rm $(dynamic_libs_dll)
-
-all: $(dynamic_libs_so)
-	@ echo "[Compiling] done"
-winall: $(dynamic_libs_dll)
-	@ echo [Compiling] done
diff --git a/nasal_builtin.h b/nasal_builtin.h
index 62bb22c..cb975e9 100644
--- a/nasal_builtin.h
+++ b/nasal_builtin.h
@@ -964,7 +964,7 @@ var builtin_dlclose(var* local,gc& ngc)
     return nil;
 }
 
-var builtin_dlcall(var* local,gc& ngc)
+var builtin_dlcallv(var* local,gc& ngc)
 {
     var fp=local[1];
     var args=local[2];
@@ -974,6 +974,15 @@ var builtin_dlcall(var* local,gc& ngc)
     return ((mod)fp.obj().ptr)(vec.data(),vec.size(),&ngc);
 }
 
+var builtin_dlcall(var* local,gc& ngc)
+{
+    var fp=local[1];
+    if(!fp.objchk(nas_obj::faddr))
+        return nas_err("dlcall","\"ptr\" is not a valid function pointer");
+    // arguments' stored place begins at local +2
+    return ((mod)fp.obj().ptr)(local+2,ngc.top-local-2,&ngc);
+}
+
 var builtin_platform(var* local,gc& ngc)
 {
 #if defined _WIN32 || defined _WIN64
@@ -1282,6 +1291,7 @@ struct
     {"__dlopen",  builtin_dlopen  },
     {"__dlsym",   builtin_dlsym   },
     {"__dlclose", builtin_dlclose },
+    {"__dlcallv", builtin_dlcallv },
     {"__dlcall",  builtin_dlcall  },
     {"__platform",builtin_platform},
     {"__md5",     builtin_md5     },
diff --git a/nasal_vm.h b/nasal_vm.h
index 596226d..ce0c387 100644
--- a/nasal_vm.h
+++ b/nasal_vm.h
@@ -706,11 +706,8 @@ inline void vm::o_callfv()
         for(u32 i=psize;i<argc;++i)
             dynamic.vec().elems.push_back(local[i]);
     }
-#ifdef _MSC_VER
-    u32 min_size=(std::min)(psize,argc);
-#else
-    u32 min_size=std::min(psize,argc);
-#endif
+
+    u32 min_size=(std::min)(psize,argc); // avoid error in MSVC
     for(u32 i=min_size;i>=1;--i)// load arguments
         local[i]=local[i-1];
     local[0]=func.local[0];// load "me"
diff --git a/stl/lib.nas b/stl/lib.nas
index 0a9db19..e8e0785 100644
--- a/stl/lib.nas
+++ b/stl/lib.nas
@@ -280,8 +280,7 @@ var md5=func(str){
     return __md5(str);
 }
 
-var io=
-{
+var io={
     SEEK_SET:0,
     SEEK_CUR:1,
     SEEK_END:2,
@@ -333,8 +332,7 @@ var fstat=func(filename){
 
 # functions that do bitwise calculation.
 # carefully use it, all the calculations are based on integer.
-var bits=
-{
+var bits={
     # i32 xor
     i32_xor: func(a,b){return __i32xor(a,b); },
     # i32 and
@@ -378,8 +376,7 @@ var bits=
 };
 
 # mostly used math functions and special constants, you know.
-var math=
-{
+var math={
     e:     2.7182818284590452354,
     pi:    3.14159265358979323846264338327950288,
     D2R:   2.7182818284590452354/180,
@@ -402,8 +399,7 @@ var math=
     min:   func(x,y){return x<y?x:y;     }
 };
 
-var unix=
-{
+var unix={
     pipe:     func(){return __pipe;},
     fork:     func(){return __fork;},
     dup2:     func(fd0,fd1){die("not supported yet");},
@@ -425,8 +421,7 @@ var unix=
 
 # dylib is the core hashmap for developers to load their own library.
 # for safe using dynamic library, you could use 'module' in stl/module.nas
-var dylib=
-{
+var dylib={
     # open dynamic lib.
     dlopen:  func(libname){
         # find dynamic lib from local dir first
@@ -451,22 +446,34 @@ var dylib=
     dlsym:   func(lib,sym){return __dlsym; },
     # close dynamic lib, this operation will make all the symbols loaded from it invalid.
     dlclose: func(lib){return __dlclose;   },
-    # call the loaded symbol.
-    dlcall:  func(ptr,args...){return __dlcall}
+    # call the loaded symbol, with infinite parameters:
+    # Caution: this may cause garbage collection process, be aware of the performance.
+    dlcall:  func(ptr,args...){return __dlcallv},
+    # get dlcall function with limited parameter list
+    limitcall: func(arg_size=0){
+        if(arg_size==0){return func(ptr){return __dlcall};}
+        else if(arg_size==1){return func(ptr,_0){return __dlcall};}
+        else if(arg_size==2){return func(ptr,_0,_1){return __dlcall};}
+        else if(arg_size==3){return func(ptr,_0,_1,_2){return __dlcall};}
+        else if(arg_size==4){return func(ptr,_0,_1,_2,_3){return __dlcall};}
+        else if(arg_size==5){return func(ptr,_0,_1,_2,_3,_4){return __dlcall};}
+        else if(arg_size==6){return func(ptr,_0,_1,_2,_3,_4,_5){return __dlcall};}
+        else if(arg_size==7){return func(ptr,_0,_1,_2,_3,_4,_5,_6){return __dlcall};}
+        else if(arg_size==8){return func(ptr,_0,_1,_2,_3,_4,_5,_6,_7){return __dlcall};}
+        else{return func(ptr,args...){return __dlcallv};}
+    }
 };
 
 # os is used to use or get some os-related info/functions.
 # windows/macOS/linux are supported.
-var os=
-{
+var os={
     # get a string that tell which os it runs on.
     platform: func(){return __platform;},
     time:     func(){return __logtime; }
 };
 
 # runtime gives us some functions that we could manage it manually.
-var runtime=
-{
+var runtime={
     # command line arguments
     argv: func(){return __sysargv;}
 };
diff --git a/stl/module.nas b/stl/module.nas
index ce6834c..bdb2888 100644
--- a/stl/module.nas
+++ b/stl/module.nas
@@ -6,7 +6,7 @@
 # all the invalid functions cannot be called
 
 var module_call_func=func(fptr,args){
-    return __dlcall;
+    return __dlcallv;
 }
 var extern={
     new: func(fptr){
@@ -14,9 +14,7 @@ var extern={
         return {
             close:func(){isopen=0;},
             call:func(args...){
-                return (!isopen)?
-                    nil:
-                    module_call_func(fptr,args);
+                return isopen?module_call_func(fptr,args):nil;
             }
         };
     }
diff --git a/test/module_test.nas b/test/module_test.nas
index 7f87809..aee3b81 100644
--- a/test/module_test.nas
+++ b/test/module_test.nas
@@ -1,5 +1,6 @@
 var libfib=func(){
     var (dd,fib,qfib)=(nil,nil,nil);
+    var invoke=dylib.limitcall(1);
     return {
         open:func(){
             if(dd==nil){
@@ -20,13 +21,13 @@ var libfib=func(){
         },
         fib:func(x){
             if(fib!=nil)
-                return dylib.dlcall(fib,x);
+                return invoke(fib,x);
             println("[error ] cannot call fib.");
             return nil;
         },
         qfib:func(x){
             if(qfib!=nil)
-                return dylib.dlcall(qfib,x);
+                return invoke(qfib,x);
             println("[error ] cannot call qfib.");
             return nil;
         }
@@ -36,9 +37,33 @@ var libfib=func(){
 println("[keys  ] ",keys(libfib));
 libfib.open();
 libfib.open();
+var tm=maketimestamp();
+tm.stamp();
 println("[result] ",libfib.fib(40));
+println("[time  ] ",tm.elapsedMSec()," ms");
+tm.stamp();
 println("[result] ",libfib.qfib(40));
+println("[time  ] ",tm.elapsedMSec()," ms");
 libfib.close();
 println("[result] ",libfib.fib(40));
 println("[result] ",libfib.qfib(40));
-libfib.close();
\ No newline at end of file
+libfib.close();
+
+var speed_test=func(){
+    var d=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+    var fd=dylib.dlsym(d,"quick_fib");
+    var vec_call=dylib.dlcall;
+    var invoke=dylib.limitcall(1);
+
+    var tm=maketimestamp();
+    tm.stamp();
+    for(var i=0;i<1e7;i+=1)
+        invoke(fd,40);
+    println("[time  ] limited call: ",tm.elapsedMSec()," ms");
+    tm.stamp();
+    for(var i=0;i<1e7;i+=1)
+        vec_call(fd,40);
+    println("[time  ] dynamic call: ",tm.elapsedMSec()," ms");
+}
+
+speed_test();
\ No newline at end of file