653 lines
22 KiB
Plaintext
653 lines
22 KiB
Plaintext
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1998 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the Q Public License version 1.0. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Emission of ARM assembly code *)
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open Misc
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open Cmm
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open Arch
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open Proc
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open Reg
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open Mach
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open Linearize
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open Emitaux
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(* Tradeoff between code size and code speed *)
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let fastcode_flag = ref true
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(* Output a label *)
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let emit_label lbl =
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emit_string ".L"; emit_int lbl
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(* Output a symbol *)
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let emit_symbol s =
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Emitaux.emit_symbol '$' s
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(* Output a pseudo-register *)
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let emit_reg r =
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match r.loc with
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Reg r -> emit_string (register_name r)
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| _ -> fatal_error "Emit_arm.emit_reg"
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(* Output the next register after the given pseudo-register *)
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let emit_next_reg r =
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match r.loc with
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Reg r -> emit_string (register_name(r + 1))
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| _ -> fatal_error "Emit_arm.emit_next_reg"
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(* Layout of the stack frame *)
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let stack_offset = ref 0
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let frame_size () =
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!stack_offset +
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4 * num_stack_slots.(0) + 8 * num_stack_slots.(1) +
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(if !contains_calls then 4 else 0)
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let slot_offset loc cl =
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match loc with
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Incoming n -> frame_size() + n
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| Local n ->
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if cl = 0
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then !stack_offset + num_stack_slots.(1) * 8 + n * 4
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else !stack_offset + n * 8
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| Outgoing n -> n
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(* Output a stack reference *)
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let emit_stack r =
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match r.loc with
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Stack s ->
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let ofs = slot_offset s (register_class r) in `[sp, #{emit_int ofs}]`
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| _ -> fatal_error "Emit_arm.emit_stack"
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(* Output an addressing mode *)
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let emit_addressing addr r n =
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match addr with
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Iindexed ofs ->
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`[{emit_reg r.(n)}, #{emit_int ofs}]`
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(* Record live pointers at call points *)
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type frame_descr =
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{ fd_lbl: int; (* Return address *)
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fd_frame_size: int; (* Size of stack frame *)
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fd_live_offset: int list } (* Offsets/regs of live addresses *)
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let frame_descriptors = ref([] : frame_descr list)
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let record_frame live =
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let lbl = new_label() in
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let live_offset = ref [] in
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Reg.Set.iter
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(function
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{typ = Addr; loc = Reg r} ->
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live_offset := (r lsl 1) + 1 :: !live_offset
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| {typ = Addr; loc = Stack s} as reg ->
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live_offset := slot_offset s (register_class reg) :: !live_offset
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| _ -> ())
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live;
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frame_descriptors :=
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{ fd_lbl = lbl;
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fd_frame_size = frame_size();
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fd_live_offset = !live_offset } :: !frame_descriptors;
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`{emit_label lbl}:`
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let emit_frame fd =
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` .word {emit_label fd.fd_lbl} + 4\n`;
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` .short {emit_int fd.fd_frame_size}\n`;
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` .short {emit_int (List.length fd.fd_live_offset)}\n`;
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List.iter
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(fun n ->
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` .short {emit_int n}\n`)
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fd.fd_live_offset;
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` .align 2\n`
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(* Names of various instructions *)
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let name_for_comparison = function
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Isigned Ceq -> "eq" | Isigned Cne -> "ne" | Isigned Cle -> "le"
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| Isigned Cge -> "ge" | Isigned Clt -> "lt" | Isigned Cgt -> "gt"
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| Iunsigned Ceq -> "eq" | Iunsigned Cne -> "ne" | Iunsigned Cle -> "ls"
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| Iunsigned Cge -> "cs" | Iunsigned Clt -> "cc" | Iunsigned Cgt -> "hi"
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let name_for_float_comparison cmp neg =
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match cmp with
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Ceq -> if neg then "ne" else "eq"
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| Cne -> if neg then "eq" else "ne"
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| Cle -> if neg then "hi" else "ls"
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| Cge -> if neg then "lt" else "ge"
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| Clt -> if neg then "pl" else "mi"
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| Cgt -> if neg then "le" else "gt"
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let name_for_int_operation = function
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Iadd -> "add"
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| Isub -> "sub"
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| Imul -> "mul"
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| Iand -> "and"
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| Ior -> "orr"
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| Ixor -> "eor"
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| _ -> assert false
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let name_for_shift_operation = function
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Ilsl -> "lsl"
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| Ilsr -> "lsr"
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| Iasr -> "asr"
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| _ -> assert false
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let name_for_shift_int_operation = function
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Ishiftadd -> "add"
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| Ishiftsub -> "sub"
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| Ishiftsubrev -> "rsb"
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let name_for_float_operation = function
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Inegf -> "mnfd"
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| Iabsf -> "absd"
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| Iaddf -> "adfd"
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| Isubf -> "sufd"
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| Imulf -> "mufd"
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| Idivf -> "dvfd"
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| Ifloatofint -> "fltd"
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| Iintoffloat -> "fixz"
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| _ -> assert false
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(* Recognize immediate operands *)
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(* Immediate operands are 8-bit immediate values, zero-extended, and rotated
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right by 0, 2, 4, ... 30 bits.
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We check only with 8-bit values shifted left 0 to 24 bits. *)
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let rec is_immed n shift =
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shift <= 24 &&
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(Nativeint.logand n (Nativeint.shift (Nativeint.from 0xFF) shift) = n ||
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is_immed n (shift + 2))
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let is_immediate n = is_immed n 0
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(* Emit a non-immediate integer constant *)
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let emit_complex_intconst r n =
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let i = ref n in
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let shift = ref 0 in
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let first = ref true in
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let ninstr = ref 0 in
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while Nativeint.sign !i <> 0 do
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if Nativeint.to_int (Nativeint.shift !i (- !shift)) land 3 = 0 then
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shift := !shift + 2
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else begin
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let mask = Nativeint.shift (Nativeint.from 0xFF) !shift in
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let bits = Nativeint.logand !i mask in
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if !first
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then ` mov {emit_reg r}, #{emit_nativeint bits} @ {emit_nativeint n}\n`
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else ` add {emit_reg r}, {emit_reg r}, #{emit_nativeint bits}\n`;
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first := false;
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shift := !shift + 8;
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i := Nativeint.sub !i bits;
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incr ninstr
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end
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done;
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!ninstr
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(* Name of current function *)
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let function_name = ref ""
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(* Entry point for tail recursive calls *)
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let tailrec_entry_point = ref 0
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(* Table of symbols referenced *)
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let symbol_constants = (Hashtbl.create 11 : (string, int) Hashtbl.t)
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(* Table of floating-point literals *)
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let float_constants = (Hashtbl.create 11 : (string, int) Hashtbl.t)
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(* Total space (in word) occupied by pending literals *)
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let num_literals = ref 0
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(* True if we've at least one pending float literal *)
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let pending_float = ref false
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(* Label a symbol or float constant *)
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let label_constant tbl s size =
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try
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Hashtbl.find tbl s
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with Not_found ->
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let lbl = new_label() in
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Hashtbl.add tbl s lbl;
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num_literals := !num_literals + size;
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lbl
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(* Emit all pending constants *)
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let emit_constants () =
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Hashtbl.iter
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(fun s lbl ->
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`{emit_label lbl}: .word {emit_symbol s}\n`)
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symbol_constants;
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Hashtbl.iter
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(fun s lbl ->
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`{emit_label lbl}: .double {emit_string s}\n`)
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float_constants;
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Hashtbl.clear symbol_constants;
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Hashtbl.clear float_constants;
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num_literals := 0;
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pending_float := false
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(* Output the assembly code for an instruction *)
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let emit_instr i =
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match i.desc with
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Lend -> 0
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| Lop(Imove | Ispill | Ireload) ->
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let src = i.arg.(0) and dst = i.res.(0) in
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if src.loc = dst.loc then 0 else begin
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match (src, dst) with
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{loc = Reg rs; typ = Int|Addr}, {loc = Reg rd; typ = Int|Addr} ->
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` mov {emit_reg dst}, {emit_reg src}\n`; 1
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| {loc = Reg rs; typ = Float}, {loc = Reg rd; typ = Float} ->
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` mvfd {emit_reg dst}, {emit_reg src}\n`; 1
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| {loc = Reg rs; typ = Float}, {loc = Reg rd; typ = Int|Addr} ->
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` stfd {emit_reg src}, [sp, #-8]!\n`;
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` ldmfd sp!, \{{emit_reg dst}, {emit_next_reg dst}}\n`; 2
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| {loc = Reg rs; typ = Int|Addr}, {loc = Stack sd} ->
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` str {emit_reg src}, {emit_stack dst}\n`; 1
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| {loc = Reg rs; typ = Float}, {loc = Stack sd} ->
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` stfd {emit_reg src}, {emit_stack dst}\n`; 1
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| {loc = Stack ss; typ = Int|Addr}, {loc = Reg rd} ->
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` ldr {emit_reg dst}, {emit_stack src}\n`; 1
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| {loc = Stack ss; typ = Float}, {loc = Reg rd} ->
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` ldfd {emit_reg dst}, {emit_stack src}\n`; 1
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| _ ->
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assert false
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end
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| Lop(Iconst_int n) ->
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let r = i.res.(0) in
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let nr = Nativeint.logxor n (Nativeint.from(-1)) in
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if is_immediate n then begin
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` mov {emit_reg r}, #{emit_nativeint n}\n`; 1
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end else if is_immediate nr then begin
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` mvn {emit_reg r}, #{emit_nativeint nr}\n`; 1
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end else
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emit_complex_intconst r n
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| Lop(Iconst_float s) ->
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if float_of_string s = 0.0 then
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` mvfd {emit_reg i.res.(0)}, #0.0\n`
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else begin
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let lbl = label_constant float_constants s 2 in
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pending_float := true;
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` ldfd {emit_reg i.res.(0)}, {emit_label lbl} @ {emit_string s}\n`
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end;
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1
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| Lop(Iconst_symbol s) ->
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let lbl = label_constant symbol_constants s 1 in
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` ldr {emit_reg i.res.(0)}, {emit_label lbl} @ {emit_symbol s}\n`; 1
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| Lop(Icall_ind) ->
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` mov lr, pc\n`;
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`{record_frame i.live} mov pc, {emit_reg i.arg.(0)}\n`; 2
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| Lop(Icall_imm s) ->
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`{record_frame i.live} bl {emit_symbol s}\n`; 1
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| Lop(Itailcall_ind) ->
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let n = frame_size() in
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if !contains_calls then
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` ldr lr, [sp, #{emit_int (n-4)}]\n`;
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if n > 0 then
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` add sp, sp, #{emit_int n}\n`;
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` mov pc, {emit_reg i.arg.(0)}\n`; 3
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| Lop(Itailcall_imm s) ->
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if s = !function_name then begin
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` b {emit_label !tailrec_entry_point}\n`; 1
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end else begin
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let n = frame_size() in
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if !contains_calls then
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` ldr lr, [sp, #{emit_int (n-4)}]\n`;
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if n > 0 then
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` add sp, sp, #{emit_int n}\n`;
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` b {emit_symbol s}\n`; 3
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end
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| Lop(Iextcall(s, alloc)) ->
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if alloc then begin
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let lbl = label_constant symbol_constants s 1 in
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` ldr r10, {emit_label lbl} @ {emit_symbol s}\n`;
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`{record_frame i.live} bl caml_c_call\n`; 2
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end else begin
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` bl {emit_symbol s}\n`; 1
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end
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| Lop(Istackoffset n) ->
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if n >= 0 then
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` sub sp, sp, #{emit_int n}\n`
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else
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` add sp, sp, #{emit_int (-n)}\n`;
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stack_offset := !stack_offset + n;
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1
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| Lop(Iload(size, addr)) ->
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let r = i.res.(0) in
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let instr =
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match size with
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Byte_unsigned -> "ldrb"
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| Byte_signed -> "ldrsb"
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| Sixteen_unsigned -> "ldrh"
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| Sixteen_signed -> "ldrsh"
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| Word ->
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begin match r.typ with
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Int | Addr -> "ldr"
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| Float -> "ldfd"
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end in
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` {emit_string instr} {emit_reg r}, {emit_addressing addr i.arg 0}\n`;
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1
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| Lop(Istore(size, addr)) ->
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let r = i.arg.(0) in
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let instr =
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match size with
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Byte_unsigned | Byte_signed -> "strb"
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| Sixteen_unsigned | Sixteen_signed -> "strh"
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| Word ->
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begin match r.typ with
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Int | Addr -> "str"
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| Float -> "stfd"
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end in
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` {emit_string instr} {emit_reg r}, {emit_addressing addr i.arg 1}\n`;
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1
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| Lop(Ialloc n) ->
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let nn = Nativeint.from n in
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if !fastcode_flag then begin
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if is_immediate nn then begin
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` ldr r10, [alloc_limit, #0]\n`;
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` sub alloc_ptr, alloc_ptr, #{emit_int n}\n`
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end else begin
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ignore(emit_complex_intconst (phys_reg 8 (*r10*)) nn);
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` sub alloc_ptr, alloc_ptr, r10\n`;
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` ldr r10, [alloc_limit, #0]\n`
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end;
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` cmp alloc_ptr, r10\n`;
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`{record_frame i.live} blcc caml_call_gc\n`;
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` add {emit_reg i.res.(0)}, alloc_ptr, #4\n`; 5
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end else if n = 8 || n = 12 || n = 16 then begin
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`{record_frame i.live} bl caml_alloc{emit_int ((n-4)/4)}\n`;
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` add {emit_reg i.res.(0)}, alloc_ptr, #4\n`; 2
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end else begin
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if is_immediate nn then
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` mov r10, #{emit_int n}\n`
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else
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ignore(emit_complex_intconst (phys_reg 8 (*r10*)) nn);
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`{record_frame i.live} bl caml_alloc\n`;
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` add {emit_reg i.res.(0)}, alloc_ptr, #4\n`; 3
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end
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| Lop(Iintop(Ilsl | Ilsr | Iasr as op)) ->
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let shift = name_for_shift_operation op in
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` mov {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, {emit_string shift} {emit_reg i.arg.(1)}\n`; 1
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| Lop(Iintop(Icomp cmp)) ->
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let comp = name_for_comparison cmp in
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` cmp {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`;
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` mov {emit_reg i.res.(0)}, #0\n`;
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` mov{emit_string comp} {emit_reg i.res.(0)}, #1\n`; 3
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| Lop(Iintop(Icheckbound)) ->
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` cmp {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`;
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` blls caml_array_bound_error\n`; 2
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| Lop(Iintop op) ->
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let instr = name_for_int_operation op in
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` {emit_string instr} {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`; 1
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| Lop(Iintop_imm(Idiv, n)) -> (* n is a power of 2 *)
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let l = Misc.log2 n in
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let r = i.res.(0) in
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` movs {emit_reg r}, {emit_reg i.arg.(0)}\n`;
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if n <= 256 then
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` addlt {emit_reg r}, {emit_reg r}, #{emit_int (n-1)}\n`
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else begin
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` addlt {emit_reg r}, {emit_reg r}, #{emit_int n}\n`;
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` sublt {emit_reg r}, {emit_reg r}, #1\n`
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end;
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` mov {emit_reg r}, {emit_reg r}, asr #{emit_int l}\n`; 4
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| Lop(Iintop_imm(Imod, n)) -> (* n is a power of 2 *)
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let l = Misc.log2 n in
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let a = i.arg.(0) in
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let r = i.res.(0) in
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let lbl = new_label() in
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` cmp {emit_reg a}, #0\n`;
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` mov {emit_reg r}, {emit_reg a}, lsl #{emit_int (32-l)}\n`;
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` mov {emit_reg r}, {emit_reg r}, lsr #{emit_int (32-l)}\n`;
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` bpl {emit_label lbl}\n`;
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` cmp {emit_reg r}, #0\n`;
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` subne {emit_reg r}, {emit_reg r}, #{emit_int n}\n`;
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`{emit_label lbl}:\n`; 6
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| Lop(Iintop_imm((Ilsl | Ilsr | Iasr as op), n)) ->
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let shift = name_for_shift_operation op in
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` mov {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, {emit_string shift} #{emit_int n}\n`; 1
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| Lop(Iintop_imm(Icomp cmp, n)) ->
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let comp = name_for_comparison cmp in
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` cmp {emit_reg i.arg.(0)}, #{emit_int n}\n`;
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` mov {emit_reg i.res.(0)}, #0\n`;
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` mov{emit_string comp} {emit_reg i.res.(0)}, #1\n`; 3
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| Lop(Iintop_imm(Icheckbound, n)) ->
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` cmp {emit_reg i.arg.(0)}, #{emit_int n}\n`;
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` blls caml_array_bound_error\n`; 2
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| Lop(Iintop_imm(op, n)) ->
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let instr = name_for_int_operation op in
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` {emit_string instr} {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, #{emit_int n}\n`; 1
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| Lop(Inegf | Iabsf | Ifloatofint | Iintoffloat as op) ->
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let instr = name_for_float_operation op in
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` {emit_string instr} {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}\n`; 1
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| Lop(Iaddf | Isubf | Imulf | Idivf as op) ->
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let instr = name_for_float_operation op in
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` {emit_string instr} {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`; 1
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| Lop(Ispecific(Ishiftarith(op, shift))) ->
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let instr = name_for_shift_int_operation op in
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` {emit_string instr} {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}`;
|
|
if shift >= 0
|
|
then `, lsl #{emit_int shift}\n`
|
|
else `, asr #{emit_int (-shift)}\n`;
|
|
1
|
|
| Lop(Ispecific(Ishiftcheckbound shift)) ->
|
|
` cmp {emit_reg i.arg.(1)}, {emit_reg i.arg.(0)}, lsr #{emit_int shift}\n`;
|
|
` blcs caml_array_bound_error\n`; 2
|
|
| Lop(Ispecific(Irevsubimm n)) ->
|
|
` rsb {emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, #{emit_int n}\n`; 1
|
|
| Lreloadretaddr ->
|
|
let n = frame_size() in
|
|
` ldr lr, [sp, #{emit_int(n-4)}]\n`; 1
|
|
| Lreturn ->
|
|
let n = frame_size() in
|
|
if n > 0 then
|
|
` add sp, sp, #{emit_int n}\n`;
|
|
` mov pc, lr\n`; 2
|
|
| Llabel lbl ->
|
|
`{emit_label lbl}:\n`; 0
|
|
| Lbranch lbl ->
|
|
` b {emit_label lbl}\n`; 1
|
|
| Lcondbranch(tst, lbl) ->
|
|
begin match tst with
|
|
Itruetest ->
|
|
` cmp {emit_reg i.arg.(0)}, #0\n`;
|
|
` bne {emit_label lbl}\n`
|
|
| Ifalsetest ->
|
|
` cmp {emit_reg i.arg.(0)}, #0\n`;
|
|
` beq {emit_label lbl}\n`
|
|
| Iinttest cmp ->
|
|
` cmp {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`;
|
|
let comp = name_for_comparison cmp in
|
|
` b{emit_string comp} {emit_label lbl}\n`
|
|
| Iinttest_imm(cmp, n) ->
|
|
` cmp {emit_reg i.arg.(0)}, #{emit_int n}\n`;
|
|
let comp = name_for_comparison cmp in
|
|
` b{emit_string comp} {emit_label lbl}\n`
|
|
| Ifloattest(cmp, neg) ->
|
|
begin match cmp with
|
|
Ceq | Cne ->
|
|
` cmf {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`
|
|
| _ ->
|
|
` cmfe {emit_reg i.arg.(0)}, {emit_reg i.arg.(1)}\n`
|
|
end;
|
|
let comp = name_for_float_comparison cmp neg in
|
|
` b{emit_string comp} {emit_label lbl}\n`
|
|
| Ioddtest ->
|
|
` tst {emit_reg i.arg.(0)}, #1\n`;
|
|
` bne {emit_label lbl}\n`
|
|
| Ieventest ->
|
|
` tst {emit_reg i.arg.(0)}, #1\n`;
|
|
` beq {emit_label lbl}\n`
|
|
end;
|
|
2
|
|
| Lcondbranch3(lbl0, lbl1, lbl2) ->
|
|
` cmp {emit_reg i.arg.(0)}, #1\n`;
|
|
begin match lbl0 with
|
|
None -> ()
|
|
| Some lbl -> ` blt {emit_label lbl}\n`
|
|
end;
|
|
begin match lbl1 with
|
|
None -> ()
|
|
| Some lbl -> ` beq {emit_label lbl}\n`
|
|
end;
|
|
begin match lbl2 with
|
|
None -> ()
|
|
| Some lbl -> ` bgt {emit_label lbl}\n`
|
|
end;
|
|
4
|
|
| Lswitch jumptbl ->
|
|
` ldr pc, [pc, {emit_reg i.arg.(0)}, lsl #2]\n`;
|
|
` mov r0, r0\n`; (* nop *)
|
|
for i = 0 to Array.length jumptbl - 1 do
|
|
` .word {emit_label jumptbl.(i)}\n`
|
|
done;
|
|
2 + Array.length jumptbl
|
|
| Lsetuptrap lbl ->
|
|
` bl {emit_label lbl}\n`; 1
|
|
| Lpushtrap ->
|
|
stack_offset := !stack_offset + 8;
|
|
` stmfd sp!, \{trap_ptr, lr}\n`;
|
|
` mov trap_ptr, sp\n`; 2
|
|
| Lpoptrap ->
|
|
` ldmfd sp!, \{trap_ptr, lr}\n`;
|
|
stack_offset := !stack_offset - 8; 1
|
|
| Lraise ->
|
|
` mov sp, trap_ptr\n`;
|
|
` ldmfd sp!, \{trap_ptr, pc}\n`; 2
|
|
|
|
(* Emission of an instruction sequence *)
|
|
|
|
let no_fallthrough = function
|
|
Lop(Itailcall_ind | Itailcall_imm _) -> true
|
|
| Lreturn -> true
|
|
| Lbranch _ -> true
|
|
| Lswitch _ -> true
|
|
| Lraise -> true
|
|
| _ -> false
|
|
|
|
let rec emit_all ninstr i =
|
|
if i.desc = Lend then () else begin
|
|
let n = emit_instr i in
|
|
let ninstr' = ninstr + n in
|
|
let limit = (if !pending_float then 127 else 511) - !num_literals in
|
|
if ninstr' >= limit - 32 && no_fallthrough i.desc then begin
|
|
emit_constants();
|
|
emit_all 0 i.next
|
|
end else
|
|
if ninstr' >= limit then begin
|
|
let lbl = new_label() in
|
|
` b {emit_label lbl}\n`;
|
|
emit_constants();
|
|
`{emit_label lbl}:\n`;
|
|
emit_all 0 i.next
|
|
end else
|
|
emit_all ninstr' i.next
|
|
end
|
|
|
|
(* Emission of a function declaration *)
|
|
|
|
let fundecl fundecl =
|
|
function_name := fundecl.fun_name;
|
|
fastcode_flag := fundecl.fun_fast;
|
|
tailrec_entry_point := new_label();
|
|
stack_offset := 0;
|
|
Hashtbl.clear symbol_constants;
|
|
Hashtbl.clear float_constants;
|
|
` .text\n`;
|
|
` .align 0\n`;
|
|
` .global {emit_symbol fundecl.fun_name}\n`;
|
|
`{emit_symbol fundecl.fun_name}:\n`;
|
|
let n = frame_size() in
|
|
if n > 0 then
|
|
` sub sp, sp, #{emit_int n}\n`;
|
|
if !contains_calls then
|
|
` str lr, [sp, #{emit_int(n - 4)}]\n`;
|
|
`{emit_label !tailrec_entry_point}:\n`;
|
|
emit_all 0 fundecl.fun_body;
|
|
emit_constants()
|
|
|
|
(* Emission of data *)
|
|
|
|
let emit_item = function
|
|
Cdefine_symbol s ->
|
|
` .global {emit_symbol s}\n`;
|
|
`{emit_symbol s}:\n`
|
|
| Cdefine_label lbl ->
|
|
`{emit_label (10000 + lbl)}:\n`
|
|
| Cint8 n ->
|
|
` .byte {emit_int n}\n`
|
|
| Cint16 n ->
|
|
` .short {emit_int n}\n`
|
|
| Cint n ->
|
|
` .word {emit_nativeint n}\n`
|
|
| Cfloat f ->
|
|
` .align 0\n`;
|
|
` .double {emit_string f}\n`
|
|
| Csymbol_address s ->
|
|
` .word {emit_symbol s}\n`
|
|
| Clabel_address lbl ->
|
|
` .word {emit_label (10000 + lbl)}\n`
|
|
| Cstring s ->
|
|
emit_string_directive " .ascii " s
|
|
| Cskip n ->
|
|
if n > 0 then ` .space {emit_int n}\n`
|
|
| Calign n ->
|
|
` .align {emit_int(Misc.log2 n)}\n`
|
|
|
|
let data l =
|
|
` .data\n`;
|
|
List.iter emit_item l
|
|
|
|
(* Beginning / end of an assembly file *)
|
|
|
|
let begin_assembly() =
|
|
`trap_ptr .req r11\n`;
|
|
`alloc_ptr .req r8\n`;
|
|
`alloc_limit .req r9\n`;
|
|
`sp .req r13\n`;
|
|
`lr .req r14\n`;
|
|
`pc .req r15\n`;
|
|
let lbl_begin = Compilenv.current_unit_name() ^ "_data_begin" in
|
|
` .data\n`;
|
|
` .global {emit_symbol lbl_begin}\n`;
|
|
`{emit_symbol lbl_begin}:\n`;
|
|
let lbl_begin = Compilenv.current_unit_name() ^ "_code_begin" in
|
|
` .text\n`;
|
|
` .global {emit_symbol lbl_begin}\n`;
|
|
`{emit_symbol lbl_begin}:\n`
|
|
|
|
let end_assembly () =
|
|
let lbl_end = Compilenv.current_unit_name() ^ "_code_end" in
|
|
` .text\n`;
|
|
` .global {emit_symbol lbl_end}\n`;
|
|
`{emit_symbol lbl_end}:\n`;
|
|
let lbl_end = Compilenv.current_unit_name() ^ "_data_end" in
|
|
` .data\n`;
|
|
` .global {emit_symbol lbl_end}\n`;
|
|
`{emit_symbol lbl_end}:\n`;
|
|
` .word 0\n`;
|
|
let lbl = Compilenv.current_unit_name() ^ "_frametable" in
|
|
` .data\n`;
|
|
` .global {emit_symbol lbl}\n`;
|
|
`{emit_symbol lbl}:\n`;
|
|
` .word {emit_int (List.length !frame_descriptors)}\n`;
|
|
List.iter emit_frame !frame_descriptors;
|
|
frame_descriptors := []
|