diff --git a/ext/dl/dl.c b/ext/dl/dl.c
index 0eda4926d7..cb370ae252 100644
--- a/ext/dl/dl.c
+++ b/ext/dl/dl.c
@@ -635,6 +635,7 @@ Init_dl()
   rb_define_const(rb_mDL, "MAX_ARG", INT2NUM(MAX_ARG));
   rb_define_const(rb_mDL, "MAX_CBARG", INT2NUM(MAX_CBARG));
   rb_define_const(rb_mDL, "MAX_CBENT", INT2NUM(MAX_CBENT));
+  rb_define_const(rb_mDL, "DLSTACK", rb_tainted_str_new2(DLSTACK_METHOD));
 
   rb_define_module_function(rb_mDL, "dlopen", rb_dl_dlopen, -1);
   rb_define_module_function(rb_mDL, "set_callback", rb_dl_set_callback, -1);
diff --git a/ext/dl/dl.h b/ext/dl/dl.h
index 5068fc6bbc..bfe83087cd 100644
--- a/ext/dl/dl.h
+++ b/ext/dl/dl.h
@@ -8,9 +8,9 @@
 #include <ruby.h>
 #include <dlconfig.h>
 
-#define DL_VERSION     "1.1.0"
+#define DL_VERSION     "1.2.0"
 #define DL_MAJOR_VERSION 1
-#define DL_MINOR_VERSION 1
+#define DL_MINOR_VERSION 2
 #define DL_PATCH_VERSION 0
 
 #if defined(HAVE_DLFCN_H)
@@ -142,32 +142,48 @@
 
 #if defined(USE_INLINE_ASM)
 # if defined(__i386__) && defined(__GNUC__)
-#   define ASM_START(sym)
-#   define ASM_END(sym)
-#   define ASM_PUSH_C(x) asm volatile ("pushl %0" :: "g" (x));
-#   define ASM_PUSH_H(x) asm volatile ("pushl %0" :: "g" (x));
-#   define ASM_PUSH_I(x) asm volatile ("pushl %0" :: "g" (x));
-#   define ASM_PUSH_L(x) asm volatile ("pushl %0" :: "g" (x));
-#   define ASM_PUSH_P(x) asm volatile ("pushl %0" :: "g" (x));
-#   define ASM_PUSH_F(x) asm volatile ("flds %0"::"g"(x));\
-                         asm volatile ("subl $4,%esp");\
-                         asm volatile ("fstps (%esp)");
-#   define ASM_PUSH_D(x) asm volatile ("fldl %0"::"g"(x));\
-                         asm volatile ("subl $8,%esp");\
-                         asm volatile ("fstpl (%esp)")
+#   define DLSTACK
+#   define DLSTACK_METHOD "asm"
+#   define DLSTACK_REVERSE
+#   define DLSTACK_PROTO
+#   define DLSTACK_ARGS
+#   define DLSTACK_START(sym)
+#   define DLSTACK_END(sym)
+#   define DLSTACK_PUSH_C(x) asm volatile ("pushl %0" :: "g" (x));
+#   define DLSTACK_PUSH_H(x) asm volatile ("pushl %0" :: "g" (x));
+#   define DLSTACK_PUSH_I(x) asm volatile ("pushl %0" :: "g" (x));
+#   define DLSTACK_PUSH_L(x) asm volatile ("pushl %0" :: "g" (x));
+#   define DLSTACK_PUSH_P(x) asm volatile ("pushl %0" :: "g" (x));
+#   define DLSTACK_PUSH_F(x) asm volatile ("flds %0"::"g"(x));\
+                             asm volatile ("subl $4,%esp");\
+                             asm volatile ("fstps (%esp)");
+#   define DLSTACK_PUSH_D(x) asm volatile ("fldl %0"::"g"(x));\
+                             asm volatile ("subl $8,%esp");\
+                             asm volatile ("fstpl (%esp)")
 # else
 # error --with-asm is not supported on this machine
 # endif
 #elif defined(USE_DLSTACK)
-# define ASM_START(sym)
-# define ASM_END(sym)
-# define ASM_PUSH_C(x)  {long v=(long)x; memcpy(sp,&v,sizeof(long)); sp++;}
-# define ASM_PUSH_H(x)  {long v=(long)x; memcpy(sp,&v,sizeof(long)); sp++;}
-# define ASM_PUSH_I(x)  {long v=(long)x; memcpy(sp,&v,sizeof(long)); sp++;}
-# define ASM_PUSH_L(x)  memcpy(sp,&x,sizeof(long)); sp++;
-# define ASM_PUSH_P(x)  memcpy(sp,&x,sizeof(void*)); sp++;
-# define ASM_PUSH_F(x)  memcpy(sp,&x,sizeof(float)); sp+=sizeof(float)/sizeof(long);
-# define ASM_PUSH_D(x)  memcpy(sp,&x,sizeof(double)); sp+=sizeof(double)/sizeof(long);
+# define DLSTACK
+# define DLSTACK_METHOD "dl"
+# define DLSTACK_PROTO long,long,long,long,long,\
+                       long,long,long,long,long,\
+                       long,long,long,long,long
+# define DLSTACK_ARGS  stack[0],stack[1],stack[2],stack[3],stack[4],\
+                       stack[5],stack[6],stack[7],stack[8],stack[9],\
+                       stack[10],stack[11],stack[12],stack[13],stack[14]
+# define DLSTACK_SIZE  (sizeof(long)*15)
+# define DLSTACK_START(sym)
+# define DLSTACK_END(sym)
+# define DLSTACK_PUSH_C(x)  {long v=(long)x; memcpy(sp,&v,sizeof(long)); sp++;}
+# define DLSTACK_PUSH_H(x)  {long v=(long)x; memcpy(sp,&v,sizeof(long)); sp++;}
+# define DLSTACK_PUSH_I(x)  {long v=(long)x; memcpy(sp,&v,sizeof(long)); sp++;}
+# define DLSTACK_PUSH_L(x)  memcpy(sp,&x,sizeof(long)); sp++;
+# define DLSTACK_PUSH_P(x)  memcpy(sp,&x,sizeof(void*)); sp++;
+# define DLSTACK_PUSH_F(x)  memcpy(sp,&x,sizeof(float)); sp+=sizeof(float)/sizeof(long);
+# define DLSTACK_PUSH_D(x)  memcpy(sp,&x,sizeof(double)); sp+=sizeof(double)/sizeof(long);
+#else
+# define DLSTACK_METHOD "none"
 #endif
 
 extern VALUE rb_mDL;
diff --git a/ext/dl/sym.c b/ext/dl/sym.c
index 5340dcb489..502e0f4bf4 100644
--- a/ext/dl/sym.c
+++ b/ext/dl/sym.c
@@ -101,7 +101,7 @@ rb_dlsym_new(void (*func)(), const char *name, const char *type)
     data->name = name ? strdup(name) : NULL;
     data->type = type ? strdup(type) : NULL;
     data->len  = type ? strlen(type) : 0;
-#if !(defined(USE_INLINE_ASM) || defined(USE_DLSTACK))
+#if !(defined(DLSTACK))
     if( data->len - 1 > MAX_ARG ){
       rb_raise(rb_eDLError, "maximum number of arguments is %d.", MAX_ARG);
     };
@@ -519,17 +519,11 @@ rb_dlsym_call(int argc, VALUE argv[], VALUE self)
 
   func = sym->func;
 
-#if defined(USE_INLINE_ASM) || defined(USE_DLSTACK)
+#if defined(DLSTACK)
   {
-#if defined(USE_DLSTACK)
-#define DLSTACK_PROTO long,long,long,long,long,\
-                      long,long,long,long,long,\
-                      long,long,long,long,long
-#define DLSTACK_ARGS  stack[0],stack[1],stack[2],stack[3],stack[4],\
-                      stack[5],stack[6],stack[7],stack[8],stack[9],\
-                      stack[10],stack[11],stack[12],stack[13],stack[14]
+#if defined(DLSTACK_SIZE)
   int  stk_size;
-  long stack[15];
+  long stack[DLSTACK_SIZE];
   long *sp;
 
   sp = stack;
@@ -538,75 +532,72 @@ rb_dlsym_call(int argc, VALUE argv[], VALUE self)
     FREE_ARGS;
     rb_raise(rb_eDLTypeError, "unknown type '%c'.", -stk_size);
   }
-  else if( stk_size > (int)(sizeof(long) * 15) ){
+  else if( stk_size > (int)(DLSTACK_SIZE) ){
     FREE_ARGS;
     rb_raise(rb_eArgError, "too many arguments.");
   }
-#elif defined(USE_INLINE_ASM)
-#define DLSTACK_PROTO
-#define DLSTACK_ARGS
 #endif
 
-  ASM_START(sym);
+  DLSTACK_START(sym);
 
-#if defined(USE_DLSTACK)
-  for( i = 0; i <= sym->len -2; i++ )
-#else
+#if defined(DLSTACK_REVERSE)
   for( i = sym->len - 2; i >= 0; i-- )
+#else
+  for( i = 0; i <= sym->len -2; i++ )
 #endif
   {
     switch( sym->type[i+1] ){
     case 'p':
     case 'P':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'a':
     case 'A':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'C':
-      ASM_PUSH_C(ANY2C(args[i]));
+      DLSTACK_PUSH_C(ANY2C(args[i]));
       break;
     case 'c':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'H':
-      ASM_PUSH_H(ANY2H(args[i]));
+      DLSTACK_PUSH_H(ANY2H(args[i]));
       break;
     case 'h':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'I':
-      ASM_PUSH_I(ANY2I(args[i]));
+      DLSTACK_PUSH_I(ANY2I(args[i]));
       break;
     case 'i':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'L':
-      ASM_PUSH_L(ANY2L(args[i]));
+      DLSTACK_PUSH_L(ANY2L(args[i]));
       break;
     case 'l':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'F':
-      ASM_PUSH_F(ANY2F(args[i]));
+      DLSTACK_PUSH_F(ANY2F(args[i]));
       break;
     case 'f':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'D':
-      ASM_PUSH_D(ANY2D(args[i]));
+      DLSTACK_PUSH_D(ANY2D(args[i]));
       break;
     case 'd':
-      ASM_PUSH_P(ANY2P(args[i]));
+      DLSTACK_PUSH_P(ANY2P(args[i]));
       break;
     case 'S':
     case 's':
-      ASM_PUSH_P(ANY2S(args[i]));
+      DLSTACK_PUSH_P(ANY2S(args[i]));
       break;
     };
   }
-  ASM_END(sym->type);
+  DLSTACK_END(sym->type);
 
   {
     switch( sym->type[0] ){
@@ -678,14 +669,14 @@ rb_dlsym_call(int argc, VALUE argv[], VALUE self)
     }
   }
   }
-#else
+#else /* defined(DLSTACK) */
   switch(ftype){
 #include "call.func"
   default:
     FREE_ARGS;
     rb_raise(rb_eDLTypeError, "unsupported function type `%s'", sym->type);
   };
-#endif
+#endif /* defined(DLSTACK) */
 
   switch( sym->type[0] ){
   case '0':
diff --git a/ext/dl/test/test.rb b/ext/dl/test/test.rb
index e6a7f33623..c4f1915387 100644
--- a/ext/dl/test/test.rb
+++ b/ext/dl/test/test.rb
@@ -31,6 +31,7 @@ print("VERSION       = #{DL::VERSION}\n")
 print("MAJOR_VERSION = #{DL::MAJOR_VERSION}\n")
 print("MINOR_VERSION = #{DL::MINOR_VERSION}\n")
 print("\n")
+print("DLSTACK   = #{DL::DLSTACK}\n")
 print("MAX_ARG   = #{DL::MAX_ARG}\n")
 print("MAX_CBARG = #{DL::MAX_CBARG}\n")
 print("MAX_CBENT = #{DL::MAX_CBENT}\n")