diff --git a/nasal_builtin.h b/nasal_builtin.h
index 90b557a..6b8362f 100644
--- a/nasal_builtin.h
+++ b/nasal_builtin.h
@@ -796,7 +796,6 @@ nasal_val* builtin_streq(nasal_val* local_scope_addr,nasal_gc& gc)
         return ret_addr;
     }
     int ret=(a_addr->get_string()==b_addr->get_string());
-    
     ret_addr->set_number((double)ret);
     return ret_addr;
 }
@@ -816,9 +815,9 @@ nasal_val* builtin_left(nasal_val* local_scope_addr,nasal_gc& gc)
     }
     std::string str=string_addr->get_string();
     int len=(int)length_addr->get_number();
-    if(len < 0) len = 0;
+    if(len<0)
+        len=0;
     std::string tmp=str.substr(0, len);
-    
     nasal_val* ret_addr=gc.gc_alloc(vm_str);
     ret_addr->set_string(tmp);
     return ret_addr;
@@ -839,11 +838,12 @@ nasal_val* builtin_right(nasal_val* local_scope_addr,nasal_gc& gc)
     } 
     std::string str=string_addr->get_string();
     int len=(int)length_addr->get_number();
-    int srclen = str.length();
-    if (len > srclen) len = srclen;
-    if(len < 0) len = 0;
+    int srclen=str.length();
+    if(len>srclen)
+        len=srclen;
+    if(len<0)
+        len=0;
     std::string tmp=str.substr(srclen-len, srclen);
-    
     nasal_val* ret_addr=gc.gc_alloc(vm_str);
     ret_addr->set_string(tmp);
     return ret_addr;
@@ -862,21 +862,8 @@ nasal_val* builtin_cmp(nasal_val* local_scope_addr,nasal_gc& gc)
         builtin_error_occurred("cmp","\"b\" must be string");
         return NULL;
     }
-    std::string a=a_addr->get_string();
-    std::string b=b_addr->get_string();
-    int alen=a.length();
-    int blen=b.length();
     nasal_val* ret_addr=gc.gc_alloc(vm_num);
-    for(int i=0; i<alen && i<blen; i++)
-    {
-        int diff = a[i] - b[i];
-        if(diff)
-        {
-            ret_addr->set_number((double)diff < 0 ? -1 : 1);
-            return ret_addr;
-        }
-    }
-    ret_addr->set_number(alen == blen ? 0 : (alen < blen ? -1 : 1));
+    ret_addr->set_number(strcmp(a_addr->get_string().data(),b_addr->get_string().data()));
     return ret_addr;
 }
 nasal_val* builtin_chr(nasal_val* local_scope_addr,nasal_gc& gc)
@@ -887,9 +874,7 @@ nasal_val* builtin_chr(nasal_val* local_scope_addr,nasal_gc& gc)
         builtin_error_occurred("chr","\"code\" must be number");
         return NULL;
     }
-    char chr[2];
-    chr[0] = (char)code_addr->get_number();
-    chr[1] = '\0';
+    char chr[2]={(char)code_addr->get_number(),'\0'};
     nasal_val* ret_addr=gc.gc_alloc(vm_str);
     ret_addr->set_string(chr);
     return ret_addr;
diff --git a/nasal_codegen.h b/nasal_codegen.h
index 9d77022..03ee912 100644
--- a/nasal_codegen.h
+++ b/nasal_codegen.h
@@ -338,7 +338,7 @@ void nasal_codegen::call_id(nasal_ast& ast)
     for(int i=0;builtin_func_table[i].func_pointer;++i)
         if(builtin_func_table[i].func_name==str)
         {
-            gen(op_builtincall,string_table[str]);
+            gen(op_builtincall,i);
             return;
         }
     gen(op_call,string_table[str]);
@@ -926,9 +926,9 @@ void nasal_codegen::print_op(int index)
     switch(exec_code[index].op)
     {
         case op_pushnum:std::cout<<'('<<number_result_table[exec_code[index].index]<<')';break;
+        case op_builtincall:std::cout<<'('<<builtin_func_table[exec_code[index].index].func_name<<')';break;
         case op_hashapp:
         case op_call:
-        case op_builtincall:
         case op_mcall:
         case op_pushstr:
         case op_callh:
diff --git a/nasal_vm.h b/nasal_vm.h
index 9a20041..e3255e8 100644
--- a/nasal_vm.h
+++ b/nasal_vm.h
@@ -30,8 +30,6 @@ private:
     std::vector<std::string> string_table;
     // number table
     std::vector<double> number_table;
-    // builtin function address table
-    std::map<std::string,nasal_val* (*)(nasal_val* x,nasal_gc& vm)> builtin_func_hashmap;
     void die(std::string);
     bool check_condition(nasal_val*);
     void opr_nop();
@@ -103,8 +101,6 @@ nasal_vm::nasal_vm()
     val_stack=new nasal_val*[val_stack_MAX_DEPTH];
     val_stack_top=val_stack;
     local_scope_stack.push(NULL);
-    for(int i=0;builtin_func_table[i].func_pointer;++i)
-        builtin_func_hashmap[builtin_func_table[i].func_name]=builtin_func_table[i].func_pointer;
     return;
 }
 nasal_vm::~nasal_vm()
@@ -899,11 +895,8 @@ void nasal_vm::opr_callf()
 }
 void nasal_vm::opr_builtincall()
 {
-    nasal_val* ret_value_addr=NULL;
-    std::string val_name=string_table[exec_code[ptr].index];
-    ret_value_addr=(*builtin_func_hashmap[val_name])(local_scope_stack.top(),vm);
+    *(++val_stack_top)=(*builtin_func_table[exec_code[ptr].index].func_pointer)(local_scope_stack.top(),vm);
     main_loop_break_mark=!builtin_die_state;
-    *(++val_stack_top)=ret_value_addr;
     return;
 }
 void nasal_vm::opr_slicebegin()