(* *********************************************************************)
(*                                                                     *)
(*              The Compcert verified compiler                         *)
(*                                                                     *)
(*          Xavier Leroy, INRIA Paris-Rocquencourt                     *)
(*                                                                     *)
(*  Copyright Institut National de Recherche en Informatique et en     *)
(*  Automatique.  All rights reserved.  This file is distributed       *)
(*  under the terms of the INRIA Non-Commercial License Agreement.     *)
(*                                                                     *)
(* *********************************************************************)

(* Printing PPC assembly code in asm syntax *)

open Printf
open Datatypes
open Maps
open Camlcoq
open Sections
open AST
open Memdata
open Asm

(* Recognition of target ABI and asm syntax *)

type target = Linux | Diab

let target = 
  match Configuration.system with
  | "linux"  -> Linux
  | "diab"   -> Diab
  | _        -> invalid_arg ("System " ^ Configuration.system ^ " not supported")

(* On-the-fly label renaming *)

let next_label = ref 100

let new_label() =
  let lbl = !next_label in incr next_label; lbl

let current_function_labels = (Hashtbl.create 39 : (label, int) Hashtbl.t)

let transl_label lbl =
  try
    Hashtbl.find current_function_labels lbl
  with Not_found ->
    let lbl' = new_label() in
    Hashtbl.add current_function_labels lbl lbl';
    lbl'

(* Basic printing functions *)

let coqint oc n =
  fprintf oc "%ld" (camlint_of_coqint n)

let raw_symbol oc s =
  fprintf oc "%s" s

let symbol oc symb =
  fprintf oc "%s" (extern_atom symb)

let symbol_offset oc (symb, ofs) =
  symbol oc symb;
  if ofs <> 0l then fprintf oc " + %ld" ofs

let label oc lbl =
  fprintf oc ".L%d" lbl

let label_low oc lbl =
  fprintf oc ".L%d@l" lbl

let label_high oc lbl =
  fprintf oc ".L%d@ha" lbl

let comment =
  match target with
  | Linux -> "#"
  | Diab -> ";"

let constant oc cst =
  match cst with
  | Cint n ->
      fprintf oc "%ld" (camlint_of_coqint n)
  | Csymbol_low(s, n) ->
      fprintf oc "(%a)@l" symbol_offset (s, camlint_of_coqint n)
  | Csymbol_high(s, n) ->
      fprintf oc "(%a)@ha" symbol_offset (s, camlint_of_coqint n)
  | Csymbol_sda(s, n) ->
      begin match target with
      | Linux ->
          fprintf oc "(%a)@sda21" symbol_offset (s, camlint_of_coqint n)
      | Diab ->
          fprintf oc "(%a)@sdarx" symbol_offset (s, camlint_of_coqint n)
      end
  | Csymbol_rel_low(s, n) ->
      fprintf oc "(%a)@sdax@l" symbol_offset (s, camlint_of_coqint n)
  | Csymbol_rel_high(s, n) ->
      fprintf oc "(%a)@sdarx@ha" symbol_offset (s, camlint_of_coqint n)

let num_crbit = function
  | CRbit_0 -> 0
  | CRbit_1 -> 1
  | CRbit_2 -> 2
  | CRbit_3 -> 3
  | CRbit_6 -> 6

let crbit oc bit =
  fprintf oc "%d" (num_crbit bit)

let int_reg_name = function
  | GPR0 -> "0"  | GPR1 -> "1"  | GPR2 -> "2"  | GPR3 -> "3"
  | GPR4 -> "4"  | GPR5 -> "5"  | GPR6 -> "6"  | GPR7 -> "7"
  | GPR8 -> "8"  | GPR9 -> "9"  | GPR10 -> "10" | GPR11 -> "11"
  | GPR12 -> "12" | GPR13 -> "13" | GPR14 -> "14" | GPR15 -> "15"
  | GPR16 -> "16" | GPR17 -> "17" | GPR18 -> "18" | GPR19 -> "19"
  | GPR20 -> "20" | GPR21 -> "21" | GPR22 -> "22" | GPR23 -> "23"
  | GPR24 -> "24" | GPR25 -> "25" | GPR26 -> "26" | GPR27 -> "27"
  | GPR28 -> "28" | GPR29 -> "29" | GPR30 -> "30" | GPR31 -> "31"

let float_reg_name = function
  | FPR0 -> "0"  | FPR1 -> "1"  | FPR2 -> "2"  | FPR3 -> "3"
  | FPR4 -> "4"  | FPR5 -> "5"  | FPR6 -> "6"  | FPR7 -> "7"
  | FPR8 -> "8"  | FPR9 -> "9"  | FPR10 -> "10" | FPR11 -> "11"
  | FPR12 -> "12" | FPR13 -> "13" | FPR14 -> "14" | FPR15 -> "15"
  | FPR16 -> "16" | FPR17 -> "17" | FPR18 -> "18" | FPR19 -> "19"
  | FPR20 -> "20" | FPR21 -> "21" | FPR22 -> "22" | FPR23 -> "23"
  | FPR24 -> "24" | FPR25 -> "25" | FPR26 -> "26" | FPR27 -> "27"
  | FPR28 -> "28" | FPR29 -> "29" | FPR30 -> "30" | FPR31 -> "31"

let ireg oc r =
  begin match target with
  | Diab  -> output_char oc 'r'
  | Linux -> ()
  end;
  output_string oc (int_reg_name r)

let ireg_or_zero oc r =
  if r = GPR0 then output_string oc "0" else ireg oc r

let freg oc r =
  begin match target with
  | Diab  -> output_char oc 'f'
  | Linux -> ()
  end;
  output_string oc (float_reg_name r)

let creg oc r =
  match target with
  | Diab  -> fprintf oc "cr%d" r
  | Linux -> fprintf oc "%d" r

let preg oc = function
  | IR r -> ireg oc r
  | FR r -> freg oc r
  | _    -> assert false

(* Names of sections *)

let name_of_section_Linux = function
  | Section_text -> ".text"
  | Section_data i -> if i then ".data" else "COMM"
  | Section_small_data i -> if i then ".sdata" else "COMM"
  | Section_const -> ".rodata"
  | Section_small_const -> ".sdata2"
  | Section_string -> ".rodata"
  | Section_literal -> ".section	.rodata.cst8,\"aM\",@progbits,8"
  | Section_jumptable -> ".text"
  | Section_user(s, wr, ex) ->
       sprintf ".section	\"%s\",\"a%s%s\",@progbits"
               s (if wr then "w" else "") (if ex then "x" else "")

let name_of_section_Diab = function
  | Section_text -> ".text"
  | Section_data i -> if i then ".data" else ".bss"
  | Section_small_data i -> if i then ".sdata" else ".sbss"
  | Section_const -> ".text"
  | Section_small_const -> ".sdata2"
  | Section_string -> ".text"
  | Section_literal -> ".text"
  | Section_jumptable -> ".text"
  | Section_user(s, wr, ex) ->
       sprintf ".section	\"%s\",,%c"
               s
               (match wr, ex with
                | true, true -> 'm'                 (* text+data *)
                | true, false -> 'd'                (* data *)
                | false, true -> 'c'                (* text *)
                | false, false -> 'r')              (* const *)

let name_of_section =
  match target with
  | Linux -> name_of_section_Linux
  | Diab  -> name_of_section_Diab

let section oc sec =
  let name = name_of_section sec in
  assert (name <> "COMM");
  fprintf oc "	%s\n" name

(* Emit .file / .loc debugging directives *)

module DebugLinux = struct
  let filename_num : (string, int) Hashtbl.t = Hashtbl.create 7
  let reset () = Hashtbl.clear filename_num
  let print_file_line oc file line =
    if !Clflags.option_g && file <> "" then begin
      let filenum = 
        try
          Hashtbl.find filename_num file
        with Not_found ->
          let n = Hashtbl.length filename_num + 1 in
          Hashtbl.add filename_num file n;
          fprintf oc "	.file	%d %S\n" n file;
          n
      in fprintf oc "	.loc	%d %s\n" filenum line
    end
end

module DebugDiab = struct
  let last_file = ref ""
  let reset () = last_file := ""
  let print_file_line oc file line =
    if !Clflags.option_g && file <> "" then begin
      if file <> !last_file then begin
        fprintf oc "	.d1file	%S\n" file;
        last_file := file
      end;
      fprintf oc "	.d1line	%s\n" line
    end
end

let print_file_line =
  match target with
  | Linux -> DebugLinux.print_file_line
  | Diab  -> DebugDiab.print_file_line

let print_location oc loc =
  if loc <> Cutil.no_loc then
    print_file_line oc (fst loc) (string_of_int (snd loc))

let reset_file_line =
  match target with
  | Linux -> DebugLinux.reset
  | Diab  -> DebugDiab.reset

(* Emit .cfi directives *)

let cfi_startproc oc =
  if Configuration.asm_supports_cfi then
    match target with
    | Linux -> fprintf oc "	.cfi_startproc\n"
    | Diab  -> ()

let cfi_endproc oc =
  if Configuration.asm_supports_cfi then
    match target with
    | Linux -> fprintf oc "	.cfi_endproc\n"
    | Diab  -> ()

let cfi_adjust oc delta =
  if Configuration.asm_supports_cfi then
    match target with
    | Linux -> fprintf oc "	.cfi_adjust_cfa_offset	%ld\n" delta
    | Diab  -> ()

let cfi_rel_offset oc reg ofs =
  if Configuration.asm_supports_cfi then
    match target with
    | Linux -> fprintf oc "	.cfi_rel_offset	%s, %ld\n" reg ofs
    | Diab  -> ()

(* Encoding masks for rlwinm instructions *)

let rolm_mask n =
  let mb = ref 0       (* location of last 0->1 transition *)
  and me = ref 32      (* location of last 1->0 transition *)
  and last = ref ((Int32.logand n 1l) <> 0l)  (* last bit seen *)
  and count = ref 0    (* number of transitions *)
  and mask = ref 0x8000_0000l in
  for mx = 0 to 31 do
    if Int32.logand n !mask <> 0l then
      if !last then () else (incr count; mb := mx; last := true)
    else
      if !last then (incr count; me := mx; last := false) else ();
    mask := Int32.shift_right_logical !mask 1
  done;
  if !me = 0 then me := 32;
  assert (!count = 2 || (!count = 0 && !last));
  (!mb, !me-1)

(* Handling of annotations *)

let re_file_line = Str.regexp "#line:\\(.*\\):\\([1-9][0-9]*\\)$"

let print_annot_stmt oc txt targs args =
  if Str.string_match re_file_line txt 0 then begin
    print_file_line oc (Str.matched_group 1 txt) (Str.matched_group 2 txt)
  end else begin
    fprintf oc "%s annotation: " comment;
    PrintAnnot.print_annot_stmt preg "R1" oc txt targs args
  end

(* Determine if the displacement of a conditional branch fits the short form *)

let short_cond_branch tbl pc lbl_dest =
  match PTree.get lbl_dest tbl with
  | None -> assert false
  | Some pc_dest -> 
      let disp = pc_dest - pc in -0x2000 <= disp && disp < 0x2000

(* Printing of instructions *)

let float_literals : (int * int64) list ref = ref []
let float32_literals : (int * int32) list ref = ref []
let jumptables : (int * label list) list ref = ref []

let print_instruction oc tbl pc fallthrough = function
  | Padd(r1, r2, r3) ->
      fprintf oc "	add	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Paddc(r1, r2, r3) ->
      fprintf oc "	addc	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Padde(r1, r2, r3) ->
      fprintf oc "	adde	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Paddi(r1, r2, c) ->
      fprintf oc "	addi	%a, %a, %a\n" ireg r1 ireg_or_zero r2 constant c
  | Paddic(r1, r2, c) ->
      fprintf oc "	addic	%a, %a, %a\n" ireg r1 ireg_or_zero r2 constant c
  | Paddis(r1, r2, c) ->
      fprintf oc "	addis	%a, %a, %a\n" ireg r1 ireg_or_zero r2 constant c
  | Paddze(r1, r2) ->
      fprintf oc "	addze	%a, %a\n" ireg r1 ireg r2
  | Pallocframe(sz, ofs) ->
      assert false
  | Pand_(r1, r2, r3) ->
      fprintf oc "	and.	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pandc(r1, r2, r3) ->
      fprintf oc "	andc	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pandi_(r1, r2, c) ->
      fprintf oc "	andi.	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Pandis_(r1, r2, c) ->
      fprintf oc "	andis.	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Pb lbl ->
      fprintf oc "	b	%a\n" label (transl_label lbl)
  | Pbctr sg ->
      fprintf oc "	bctr\n"
  | Pbctrl sg ->
      fprintf oc "	bctrl\n"
  | Pbdnz lbl ->
      fprintf oc "	bdnz	%a\n" label (transl_label lbl)
  | Pbf(bit, lbl) ->
      if !Clflags.option_faligncondbranchs > 0 then
        fprintf oc "	.balign	%d\n" !Clflags.option_faligncondbranchs;
      if short_cond_branch tbl pc lbl then
        fprintf oc "	bf	%a, %a\n" crbit bit label (transl_label lbl)
      else begin
        let next = new_label() in
        fprintf oc "	bt	%a, %a\n" crbit bit label next;
        fprintf oc "	b	%a\n" label (transl_label lbl);
        fprintf oc "%a:\n" label next
      end
  | Pbl(s, sg) ->
      fprintf oc "	bl	%a\n" symbol s
  | Pbs(s, sg) ->
      fprintf oc "	b	%a\n" symbol s
  | Pblr ->
      fprintf oc "	blr\n"
  | Pbt(bit, lbl) ->
      if !Clflags.option_faligncondbranchs > 0 then
        fprintf oc "	.balign	%d\n" !Clflags.option_faligncondbranchs;
      if short_cond_branch tbl pc lbl then
        fprintf oc "	bt	%a, %a\n" crbit bit label (transl_label lbl)
      else begin
        let next = new_label() in
        fprintf oc "	bf	%a, %a\n" crbit bit label next;
        fprintf oc "	b	%a\n" label (transl_label lbl);
        fprintf oc "%a:\n" label next
      end
  | Pbtbl(r, tbl) ->
      let lbl = new_label() in
      fprintf oc "%s begin pseudoinstr btbl(%a)\n" comment ireg r;
      fprintf oc "%s jumptable [ " comment;
      List.iter (fun l -> fprintf oc "%a " label (transl_label l)) tbl;
      fprintf oc "]\n";
      fprintf oc "	slwi    %a, %a, 2\n" ireg GPR12 ireg r;
      fprintf oc "	addis	%a, %a, %a\n" ireg GPR12 ireg GPR12 label_high lbl;
      fprintf oc "	lwz	%a, %a(%a)\n" ireg GPR12 label_low lbl ireg GPR12;
      fprintf oc "	mtctr	%a\n" ireg GPR12;
      fprintf oc "	bctr\n";
      jumptables := (lbl, tbl) :: !jumptables;
      fprintf oc "%s end pseudoinstr btbl\n" comment
  | Pcmplw(r1, r2) ->
      fprintf oc "	cmplw	%a, %a, %a\n" creg 0 ireg r1 ireg r2
  | Pcmplwi(r1, c) ->
      fprintf oc "	cmplwi	%a, %a, %a\n" creg 0 ireg r1 constant c
  | Pcmpw(r1, r2) ->
      fprintf oc "	cmpw	%a, %a, %a\n" creg 0 ireg r1 ireg r2
  | Pcmpwi(r1, c) ->
      fprintf oc "	cmpwi	%a, %a, %a\n" creg 0 ireg r1 constant c
  | Pcntlz(r1, r2) ->
      fprintf oc "	cntlz	%a, %a\n" ireg r1 ireg r2
  | Pcreqv(c1, c2, c3) ->
      fprintf oc "	creqv	%a, %a, %a\n" crbit c1 crbit c2 crbit c3
  | Pcror(c1, c2, c3) ->
      fprintf oc "	cror	%a, %a, %a\n" crbit c1 crbit c2 crbit c3
  | Pcrxor(c1, c2, c3) ->
      fprintf oc "	crxor	%a, %a, %a\n" crbit c1 crbit c2 crbit c3
  | Pdivw(r1, r2, r3) ->
      fprintf oc "	divw	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pdivwu(r1, r2, r3) ->
      fprintf oc "	divwu	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Peieio ->
      fprintf oc "	eieio\n"
  | Peqv(r1, r2, r3) ->
      fprintf oc "	eqv	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pextsb(r1, r2) ->
      fprintf oc "	extsb	%a, %a\n" ireg r1 ireg r2
  | Pextsh(r1, r2) ->
      fprintf oc "	extsh	%a, %a\n" ireg r1 ireg r2
  | Pfreeframe(sz, ofs) ->
      assert false
  | Pfabs(r1, r2) | Pfabss(r1, r2) ->
      fprintf oc "	fabs	%a, %a\n" freg r1 freg r2
  | Pfadd(r1, r2, r3) ->
      fprintf oc "	fadd	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfadds(r1, r2, r3) ->
      fprintf oc "	fadds	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfcmpu(r1, r2) ->
      fprintf oc "	fcmpu	%a, %a, %a\n" creg 0 freg r1 freg r2
  | Pfcti(r1, r2) ->
      assert false
  | Pfctiw(r1, r2) ->
      fprintf oc "	fctiw	%a, %a\n" freg r1 freg r2
  | Pfctiwz(r1, r2) ->
      fprintf oc "	fctiwz	%a, %a\n" freg r1 freg r2
  | Pfdiv(r1, r2, r3) ->
      fprintf oc "	fdiv	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfdivs(r1, r2, r3) ->
      fprintf oc "	fdivs	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfmake(rd, r1, r2) ->
      assert false
  | Pfmr(r1, r2) ->
      fprintf oc "	fmr	%a, %a\n" freg r1 freg r2
  | Pfmul(r1, r2, r3) ->
      fprintf oc "	fmul	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfmuls(r1, r2, r3) ->
      fprintf oc "	fmuls	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfneg(r1, r2) | Pfnegs(r1, r2) ->
      fprintf oc "	fneg	%a, %a\n" freg r1 freg r2
  | Pfrsp(r1, r2) ->
      fprintf oc "	frsp	%a, %a\n" freg r1 freg r2
  | Pfxdp(r1, r2) ->
      assert false
  | Pfsub(r1, r2, r3) ->
      fprintf oc "	fsub	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfsubs(r1, r2, r3) ->
      fprintf oc "	fsubs	%a, %a, %a\n" freg r1 freg r2 freg r3
  | Pfmadd(r1, r2, r3, r4) ->
      fprintf oc "	fmadd	%a, %a, %a, %a\n" freg r1 freg r2 freg r3 freg r4
  | Pfmsub(r1, r2, r3, r4) ->
      fprintf oc "	fmsub	%a, %a, %a, %a\n" freg r1 freg r2 freg r3 freg r4
  | Pfnmadd(r1, r2, r3, r4) ->
      fprintf oc "	fnmadd	%a, %a, %a, %a\n" freg r1 freg r2 freg r3 freg r4
  | Pfnmsub(r1, r2, r3, r4) ->
      fprintf oc "	fnmsub	%a, %a, %a, %a\n" freg r1 freg r2 freg r3 freg r4
  | Pfsqrt(r1, r2) ->
      fprintf oc "	fsqrt	%a, %a\n" freg r1 freg r2    
  | Pfrsqrte(r1, r2) ->
      fprintf oc "	frsqrte	%a, %a\n" freg r1 freg r2    
  | Pfres(r1, r2) ->
      fprintf oc "	fres	%a, %a\n" freg r1 freg r2    
  | Pfsel(r1, r2, r3, r4) ->
      fprintf oc "	fsel	%a, %a, %a, %a\n" freg r1 freg r2 freg r3 freg r4
  | Pisync ->
      fprintf oc "	isync\n"
  | Plbz(r1, c, r2) ->
      fprintf oc "	lbz	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Plbzx(r1, r2, r3) ->
      fprintf oc "	lbzx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Plfd(r1, c, r2)  | Plfd_a(r1, c, r2) ->
      fprintf oc "	lfd	%a, %a(%a)\n" freg r1 constant c ireg r2
  | Plfdx(r1, r2, r3) | Plfdx_a(r1, r2, r3) ->
      fprintf oc "	lfdx	%a, %a, %a\n" freg r1 ireg r2 ireg r3
  | Plfs(r1, c, r2) ->
      fprintf oc "	lfs	%a, %a(%a)\n" freg r1 constant c ireg r2
  | Plfsx(r1, r2, r3) ->
      fprintf oc "	lfsx	%a, %a, %a\n" freg r1 ireg r2 ireg r3
  | Plha(r1, c, r2) ->
      fprintf oc "	lha	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Plhax(r1, r2, r3) ->
      fprintf oc "	lhax	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Plhbrx(r1, r2, r3) ->
      fprintf oc "	lhbrx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Plhz(r1, c, r2) ->
      fprintf oc "	lhz	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Plhzx(r1, r2, r3) ->
      fprintf oc "	lhzx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Plfi(r1, c) ->
      let lbl = new_label() in
      fprintf oc "	addis	%a, 0, %a\n" ireg GPR12 label_high lbl;
      fprintf oc "	lfd	%a, %a(%a) %s %.18g\n" freg r1 label_low lbl ireg GPR12 comment (camlfloat_of_coqfloat c);
      float_literals := (lbl, camlint64_of_coqint (Floats.Float.to_bits c)) :: !float_literals;
  | Plfis(r1, c) ->
      let lbl = new_label() in
      fprintf oc "	addis	%a, 0, %a\n" ireg GPR12 label_high lbl;
      fprintf oc "	lfs	%a, %a(%a) %s %.18g\n" freg r1 label_low lbl ireg GPR12 comment (camlfloat_of_coqfloat32 c);
      float32_literals := (lbl, camlint_of_coqint (Floats.Float32.to_bits c)) :: !float32_literals;
  | Plwbrx(r1, r2, r3) ->
      fprintf oc "	lwbrx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Plwz(r1, c, r2) | Plwz_a(r1, c, r2) ->
      fprintf oc "	lwz	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Plwzu(r1, c, r2) ->
      fprintf oc "	lwzu	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Plwzx(r1, r2, r3) | Plwzx_a(r1, r2, r3) ->
      fprintf oc "	lwzx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pmfcr(r1) ->
      fprintf oc "	mfcr	%a\n" ireg r1
  | Pmfcrbit(r1, bit) ->
      assert false
  | Pmflr(r1) ->
      fprintf oc "	mflr	%a\n" ireg r1
  | Pmr(r1, r2) ->
      fprintf oc "	mr	%a, %a\n" ireg r1 ireg r2
  | Pmtctr(r1) ->
      fprintf oc "	mtctr	%a\n" ireg r1
  | Pmtlr(r1) ->
      fprintf oc "	mtlr	%a\n" ireg r1
  | Pmulli(r1, r2, c) ->
      fprintf oc "	mulli	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Pmullw(r1, r2, r3) ->
      fprintf oc "	mullw	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pmulhw(r1, r2, r3) ->
      fprintf oc "	mulhw	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pmulhwu(r1, r2, r3) ->
      fprintf oc "	mulhwu	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pnand(r1, r2, r3) ->
      fprintf oc "	nand	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pnor(r1, r2, r3) ->
      fprintf oc "	nor	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Por(r1, r2, r3) ->
      fprintf oc "	or	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Porc(r1, r2, r3) ->
      fprintf oc "	orc	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pori(r1, r2, c) ->
      fprintf oc "	ori	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Poris(r1, r2, c) ->
      fprintf oc "	oris	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Prlwinm(r1, r2, c1, c2) ->
      let (mb, me) = rolm_mask (camlint_of_coqint c2) in
      fprintf oc "	rlwinm	%a, %a, %ld, %d, %d %s 0x%lx\n"
                ireg r1 ireg r2 (camlint_of_coqint c1) mb me
                comment (camlint_of_coqint c2)
  | Prlwimi(r1, r2, c1, c2) ->
      let (mb, me) = rolm_mask (camlint_of_coqint c2) in
      fprintf oc "	rlwimi	%a, %a, %ld, %d, %d %s 0x%lx\n"
                ireg r1 ireg r2 (camlint_of_coqint c1) mb me
                comment (camlint_of_coqint c2)
  | Pslw(r1, r2, r3) ->
      fprintf oc "	slw	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Psraw(r1, r2, r3) ->
      fprintf oc "	sraw	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Psrawi(r1, r2, c) ->
      fprintf oc "	srawi	%a, %a, %ld\n" ireg r1 ireg r2 (camlint_of_coqint c)
  | Psrw(r1, r2, r3) ->
      fprintf oc "	srw	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pstb(r1, c, r2) ->
      fprintf oc "	stb	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Pstbx(r1, r2, r3) ->
      fprintf oc "	stbx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pstfd(r1, c, r2) | Pstfd_a(r1, c, r2) ->
      fprintf oc "	stfd	%a, %a(%a)\n" freg r1 constant c ireg r2
  | Pstfdu(r1, c, r2) ->
      fprintf oc "	stfdu	%a, %a(%a)\n" freg r1 constant c ireg r2
  | Pstfdx(r1, r2, r3) | Pstfdx_a(r1, r2, r3) ->
      fprintf oc "	stfdx	%a, %a, %a\n" freg r1 ireg r2 ireg r3
  | Pstfs(r1, c, r2) ->
      fprintf oc "	stfs	%a, %a(%a)\n" freg r1 constant c ireg r2
  | Pstfsx(r1, r2, r3) ->
      fprintf oc "	stfsx	%a, %a, %a\n" freg r1 ireg r2 ireg r3
  | Psth(r1, c, r2) ->
      fprintf oc "	sth	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Psthx(r1, r2, r3) ->
      fprintf oc "	sthx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Psthbrx(r1, r2, r3) ->
      fprintf oc "	sthbrx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pstw(r1, c, r2) | Pstw_a(r1, c, r2) ->
      fprintf oc "	stw	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Pstwu(r1, c, r2) ->
      fprintf oc "	stwu	%a, %a(%a)\n" ireg r1 constant c ireg r2
  | Pstwx(r1, r2, r3) | Pstwx_a(r1, r2, r3) ->
      fprintf oc "	stwx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pstwxu(r1, r2, r3) ->
      fprintf oc "	stwxu	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pstwbrx(r1, r2, r3) ->
      fprintf oc "	stwbrx	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Psubfc(r1, r2, r3) ->
      fprintf oc "	subfc	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Psubfe(r1, r2, r3) ->
      fprintf oc "	subfe	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Psubfze(r1, r2) ->
      fprintf oc "	subfze	%a, %a\n" ireg r1 ireg r2
  | Psubfic(r1, r2, c) ->
      fprintf oc "	subfic	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Psync ->
      fprintf oc "	sync\n"
  | Ptrap ->
      fprintf oc "	trap\n"
  | Pxor(r1, r2, r3) ->
      fprintf oc "	xor	%a, %a, %a\n" ireg r1 ireg r2 ireg r3
  | Pxori(r1, r2, c) ->
      fprintf oc "	xori	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Pxoris(r1, r2, c) ->
      fprintf oc "	xoris	%a, %a, %a\n" ireg r1 ireg r2 constant c
  | Plabel lbl ->
      if (not fallthrough) && !Clflags.option_falignbranchtargets > 0 then
        fprintf oc "	.balign	%d\n" !Clflags.option_falignbranchtargets;
      fprintf oc "%a:\n" label (transl_label lbl)
  | Pbuiltin(ef, args, res) ->
      begin match ef with
      | EF_inline_asm txt ->
          fprintf oc "%s begin inline assembly\n" comment;
          fprintf oc "	%s\n" (extern_atom txt);
          fprintf oc "%s end inline assembly\n" comment
      | _ ->
          assert false
      end
  | Pannot(ef, args) ->
      begin match ef with
      | EF_annot(txt, targs) ->
          print_annot_stmt oc (extern_atom txt) targs args
      | _ ->
          assert false
      end
  | Pcfi_adjust n ->
      cfi_adjust oc (camlint_of_coqint n)
  | Pcfi_rel_offset n ->
      cfi_rel_offset oc "lr" (camlint_of_coqint n)

(* Determine if an instruction falls through *)

let instr_fall_through = function
  | Pb _ -> false
  | Pbctr _ -> false
  | Pbs _ -> false
  | Pblr -> false
  | _ -> true

(* Estimate the size of an Asm instruction encoding, in number of actual
   PowerPC instructions.  We can over-approximate. *)

let instr_size = function
  | Pbf(bit, lbl) -> 2
  | Pbt(bit, lbl) -> 2
  | Pbtbl(r, tbl) -> 5
  | Plfi(r1, c) -> 2
  | Plfis(r1, c) -> 2
  | Plabel lbl -> 0
  | Pbuiltin(ef, args, res) -> 0
  | Pannot(ef, args) -> 0
  | Pcfi_adjust _ | Pcfi_rel_offset _ -> 0
  | _ -> 1

(* Build a table label -> estimated position in generated code.
   Used to predict if relative conditional branches can use the short form. *)

let rec label_positions tbl pc = function
  | [] -> tbl
  | Plabel lbl :: c -> label_positions (PTree.set lbl pc tbl) pc c
  | i :: c -> label_positions tbl (pc + instr_size i) c

(* Emit a sequence of instructions *)

let rec print_instructions oc tbl pc fallthrough = function
  | [] -> ()
  | i :: c ->
      print_instruction oc tbl pc fallthrough i;
      print_instructions oc tbl (pc + instr_size i) (instr_fall_through i) c

(* Print the code for a function *)

let print_literal64 oc (lbl, n) =
  let nlo = Int64.to_int32 n
  and nhi = Int64.to_int32(Int64.shift_right_logical n 32) in
  fprintf oc "%a:	.long	0x%lx, 0x%lx\n" label lbl nhi nlo

let print_literal32 oc (lbl, n) =
  fprintf oc "%a:	.long	0x%lx\n" label lbl n

let print_jumptable oc (lbl, tbl) =
  fprintf oc "%a:" label lbl;
  List.iter
    (fun l -> fprintf oc "	.long	%a\n" label (transl_label l))
    tbl

let print_function oc name fn =
  Hashtbl.clear current_function_labels;
  float_literals := [];
  float32_literals := [];
  jumptables := [];
  let (text, lit, jmptbl) =
    match C2C.atom_sections name with
    | [t;l;j] -> (t, l, j)
    |    _    -> (Section_text, Section_literal, Section_jumptable) in
  section oc text;
  let alignment =
    match !Clflags.option_falignfunctions with Some n -> n | None -> 4 in
  fprintf oc "	.balign %d\n" alignment;
  if not (C2C.atom_is_static name) then
    fprintf oc "	.globl %a\n" symbol name;
  fprintf oc "%a:\n" symbol name;
  print_location oc (C2C.atom_location name);
  cfi_startproc oc;
  print_instructions oc (label_positions PTree.empty 0 fn.fn_code) 
                        0 true fn.fn_code;
  cfi_endproc oc;
  fprintf oc "	.type	%a, @function\n" symbol name;
  fprintf oc "	.size	%a, . - %a\n" symbol name symbol name;
  if !float_literals <> [] || !float32_literals <> [] then begin
    section oc lit;
    fprintf oc "	.balign 8\n";
    List.iter (print_literal64 oc) !float_literals;
    List.iter (print_literal32 oc) !float32_literals;
    float_literals := []; float32_literals := []
  end;
  if !jumptables <> [] then begin
    section oc jmptbl;
    fprintf oc "	.balign 4\n";
    List.iter (print_jumptable oc) !jumptables;
    jumptables := []
  end

(* Generation of whole programs *)

let print_fundef oc name defn =
  match defn with
  | Internal code ->
      print_function oc name code
  | External _ ->
      ()

let print_init oc = function
  | Init_int8 n ->
      fprintf oc "	.byte	%ld\n" (camlint_of_coqint n)
  | Init_int16 n ->
      fprintf oc "	.short	%ld\n" (camlint_of_coqint n)
  | Init_int32 n ->
      fprintf oc "	.long	%ld\n" (camlint_of_coqint n)
  | Init_int64 n ->
      let b = camlint64_of_coqint n in
      fprintf oc "	.long	0x%Lx, 0x%Lx\n"
                 (Int64.shift_right_logical b 32)
                 (Int64.logand b 0xFFFFFFFFL)
  | Init_float32 n ->
      fprintf oc "	.long	0x%lx %s %.18g\n"
                 (camlint_of_coqint (Floats.Float32.to_bits n))
                 comment (camlfloat_of_coqfloat n)
  | Init_float64 n ->
      let b = camlint64_of_coqint (Floats.Float.to_bits n) in
      fprintf oc "	.long	0x%Lx, 0x%Lx %s %.18g\n"
                 (Int64.shift_right_logical b 32)
                 (Int64.logand b 0xFFFFFFFFL)
                 comment (camlfloat_of_coqfloat n)
  | Init_space n ->
      if Z.gt n Z.zero then
        fprintf oc "	.space	%s\n" (Z.to_string n)
  | Init_addrof(symb, ofs) ->
      fprintf oc "	.long	%a\n" 
                 symbol_offset (symb, camlint_of_coqint ofs)

let print_init_data oc name id =
  if Str.string_match PrintCsyntax.re_string_literal (extern_atom name) 0
  && List.for_all (function Init_int8 _ -> true | _ -> false) id
  then
    fprintf oc "	.ascii	\"%s\"\n" (PrintCsyntax.string_of_init id)
  else
    List.iter (print_init oc) id

let print_var oc name v =
  match v.gvar_init with
  | [] -> ()
  | _  ->
      let sec =
        match C2C.atom_sections name with
        | [s] -> s
        |  _  -> Section_data true
      and align =
        match C2C.atom_alignof name with
        | Some a -> a
        | None -> 8 in (* 8-alignment is a safe default *)
      let name_sec =
        name_of_section sec in
      if name_sec <> "COMM" then begin
        fprintf oc "	%s\n" name_sec;
        fprintf oc "	.balign	%d\n" align;
        if not (C2C.atom_is_static name) then
          fprintf oc "	.globl	%a\n" symbol name;
        fprintf oc "%a:\n" symbol name;
        print_init_data oc name v.gvar_init;
        fprintf oc "	.type	%a, @object\n" symbol name;
        fprintf oc "	.size	%a, . - %a\n" symbol name symbol name
      end else begin
        let sz =
          match v.gvar_init with [Init_space sz] -> sz | _ -> assert false in
        fprintf oc "	%s	%a, %s, %d\n"
          (if C2C.atom_is_static name then ".lcomm" else ".comm")
          symbol name
          (Z.to_string sz)
          align
      end

let print_globdef oc (name, gdef) =
  match gdef with
  | Gfun f -> print_fundef oc name f
  | Gvar v -> print_var oc name v

let print_prologue oc =
  match target with
  | Linux ->
      ()
  | Diab ->
      fprintf oc "	.xopt	align-fill-text=0x60000000\n";
      if !Clflags.option_g then
        fprintf oc "	.xopt	asm-debug-on\n"

let print_program oc p =
  reset_file_line();
  PrintAnnot.print_version_and_options oc comment;
  print_prologue oc;
  List.iter (print_globdef oc) p.prog_defs