ocaml/asmcomp/arch_i386.ml

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2.7 KiB
OCaml

(* Specific operations for the Intel 386 processor *)
type addressing_mode =
Ibased of string * int (* symbol + displ *)
| Iindexed of int (* reg + displ *)
| Iindexed2 of int (* reg + reg + displ *)
| Iscaled of int * int (* reg * scale + displ *)
| Iindexed2scaled of int * int (* reg + reg * scale + displ *)
type specific_operation =
Ilea of addressing_mode (* Lea gives scaled adds *)
| Istore_int of int * addressing_mode (* Store an integer constant *)
| Istore_symbol of string * addressing_mode (* Store a symbol *)
| Ioffset_loc of int * addressing_mode (* Add a constant to a location *)
(* Sizes, endianness *)
let big_endian = false
let size_addr = 4
let size_int = 4
let size_float = 8
(* Operations on addressing modes *)
let identity_addressing = Iindexed 0
let offset_addressing addr delta =
match addr with
Ibased(s, n) -> Ibased(s, n + delta)
| Iindexed n -> Iindexed(n + delta)
| Iindexed2 n -> Iindexed2(n + delta)
| Iscaled(scale, n) -> Iscaled(scale, n + delta)
| Iindexed2scaled(scale, n) -> Iindexed2scaled(scale, n + delta)
let num_args_addressing = function
Ibased(s, n) -> 0
| Iindexed n -> 1
| Iindexed2 n -> 2
| Iscaled(scale, n) -> 1
| Iindexed2scaled(scale, n) -> 2
(* Printing operations and addressing modes *)
open Format
let print_addressing printreg addr arg =
match addr with
Ibased(s, 0) ->
print_string "\""; print_string s; print_string "\""
| Ibased(s, n) ->
print_string "\""; print_string s; print_string "\" + "; print_int n
| Iindexed n ->
printreg arg.(0);
if n <> 0 then begin print_string " + "; print_int n end
| Iindexed2 n ->
printreg arg.(0); print_string " + "; printreg arg.(1);
if n <> 0 then begin print_string " + "; print_int n end
| Iscaled(scale, n) ->
printreg arg.(0); print_string " * "; print_int scale;
if n <> 0 then begin print_string " + "; print_int n end
| Iindexed2scaled(scale, n) ->
printreg arg.(0); print_string " + "; printreg arg.(1);
print_string " * "; print_int scale;
if n <> 0 then begin print_string " + "; print_int n end
let print_specific_operation printreg op arg =
match op with
Ilea addr -> print_addressing printreg addr arg
| Istore_int(n, addr) ->
print_string "["; print_addressing printreg addr arg;
print_string "] := "; print_int n
| Istore_symbol(lbl, addr) ->
print_string "["; print_addressing printreg addr arg;
print_string "] := \""; print_string lbl; print_string "\""
| Ioffset_loc(n, addr) ->
print_string "["; print_addressing printreg addr arg;
print_string "] +:= "; print_int n