rtl.def

["Bharati Bhole" <bharati.bhole@xxxxxxxxx>]

Hi,
Could anyone plz tell me what the file rtl.def does. I am not able to
understand it.
It is used in enumerator like -
enum rtx_code {
#define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) ENUM,
#include "rtl.def"
#undef DEF_RTL_EXPR
          NUM_RTX_CODE
};
The above macro is defined in gengtype.c. And i am not geting what is
meaning and usefulness of this.
Thanks.
Bharati.