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