cpu/ppc/field.fth

purpose: Structures and fields for PowerPC
\ See license at end of file

\ field creates words which add their offset within the structure
\ to the base address of the structure

: struct  ( -- 0 )  0  ;

: field  \ name  ( offset size -- offset+size )
   create over , +

   \ The high level equivalen of what the following machine code is:
   \    does> @ file @ + ;
   \ We write it in code because the metacompiler facilities for
   \ resolving DOES> clauses are clumsy

   ;code  ( struct-adr -- field-adr )
      pop-to-t0			\ Get the struct address
      lwz   tos,0(tos)		\ Get the structure member offset
      add   tos,tos,t0		\ Return the structure member address
c;

\ LICENSE_BEGIN
\ Copyright (c) 2007 FirmWorks
\ 
\ Permission is hereby granted, free of charge, to any person obtaining
\ a copy of this software and associated documentation files (the
\ "Software"), to deal in the Software without restriction, including
\ without limitation the rights to use, copy, modify, merge, publish,
\ distribute, sublicense, and/or sell copies of the Software, and to
\ permit persons to whom the Software is furnished to do so, subject to
\ the following conditions:
\ 
\ The above copyright notice and this permission notice shall be
\ included in all copies or substantial portions of the Software.
\ 
\ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
\ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
\ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
\ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
\ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
\ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
\ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\
\ LICENSE_END