{

    This file is part of the Free Pascal run time library.
    Copyright (c) 2003 by the Free Pascal development team.

    Processor dependent implementation for the system unit for
    ARM

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 **********************************************************************}

{$asmmode gas}

const
  cpu_has_edsp : boolean = false;
  in_edsp_test : boolean = false;
var
  moveproc : pointer;

procedure fpc_cpuinit;
begin
{$if not(defined(wince)) and not(defined(gba)) and not(defined(nds))}
  asm
    rfs r0
    and r0,r0,#0xffe0ffff
    orr r0,r0,#0x00020000
    wfs r0
  end;
{$endif}
end;

{$ifdef wince}
function _controlfp(new: DWORD; mask: DWORD): DWORD; cdecl; external 'coredll';

{$define FPC_SYSTEM_HAS_SYSRESETFPU}
Procedure SysResetFPU;{$ifdef SYSTEMINLINE}inline;{$endif}
begin
  softfloat_exception_flags:=0;
  softfloat_exception_mask:=float_flag_underflow or float_flag_inexact or float_flag_denormal;
  { Enable FPU exceptions, but disable INEXACT, UNDERFLOW, DENORMAL }
  { FPU precision 64 bit, rounding to nearest, affine infinity }
  _controlfp($000C0003, $030F031F);
end;
{$endif wince}

{****************************************************************************
                       stack frame related stuff
****************************************************************************}

{$IFNDEF INTERNAL_BACKTRACE}
{$define FPC_SYSTEM_HAS_GET_FRAME}
function get_frame:pointer;assembler;nostackframe;{$ifdef SYSTEMINLINE}inline;{$endif}
asm
  mov    r0,r11
end ['R0'];
{$ENDIF not INTERNAL_BACKTRACE}

{$define FPC_SYSTEM_HAS_GET_CALLER_ADDR}
function get_caller_addr(framebp:pointer):pointer;assembler;{$ifdef SYSTEMINLINE}inline;{$endif}
asm
  movs r0,r0
  beq .Lg_a_null
  ldr r0,[r0,#-4]
.Lg_a_null:
end ['R0'];


{$define FPC_SYSTEM_HAS_GET_CALLER_FRAME}
function get_caller_frame(framebp:pointer):pointer;assembler;{$ifdef SYSTEMINLINE}inline;{$endif}
asm
  movs r0,r0
  beq .Lgnf_null
  ldr r0,[r0,#-12]
.Lgnf_null:
end ['R0'];


{$define FPC_SYSTEM_HAS_SPTR}
Function Sptr : pointer;assembler;{$ifdef SYSTEMINLINE}inline;{$endif}
asm
  mov    r0,sp
end ['R0'];


{$define FPC_SYSTEM_HAS_FILLCHAR}
Procedure FillChar(var x;count:longint;value:byte);assembler;nostackframe;
asm
        // less than 0?
        cmp r1,#0
        movlt pc,lr
        mov     r3,r0
        cmp     r1,#8           // at least 8 bytes to do?
        blt     .LFillchar2
        orr r2,r2,r2,lsl #8
        orr r2,r2,r2,lsl #16
.LFillchar0:
        tst     r3,#3           // aligned yet?
        strneb r2,[r3],#1
        subne   r1,r1,#1
        bne     .LFillchar0
        mov     ip,r2
.LFillchar1:
        cmp     r1,#8           // 8 bytes still to do?
        blt     .LFillchar2
        stmia   r3!,{r2,ip}
        sub     r1,r1,#8
        cmp     r1,#8           // 8 bytes still to do?
        blt     .LFillchar2
        stmia   r3!,{r2,ip}
        sub     r1,r1,#8
        cmp     r1,#8           // 8 bytes still to do?
        blt     .LFillchar2
        stmia   r3!,{r2,ip}
        sub     r1,r1,#8
        cmp     r1,#8           // 8 bytes still to do?
        stmgeia r3!,{r2,ip}
        subge   r1,r1,#8
        bge     .LFillchar1
.LFillchar2:
        movs r1,r1              // anything left?
        moveq pc,lr
        rsb     r1,r1,#7
        add     pc,pc,r1,lsl #2
        mov     r0,r0
        strb r2,[r3],#1
        strb r2,[r3],#1
        strb r2,[r3],#1
        strb r2,[r3],#1
        strb r2,[r3],#1
        strb r2,[r3],#1
        strb r2,[r3],#1
        mov pc,lr
end;


{$ifndef FPC_SYSTEM_HAS_MOVE}
{$define FPC_SYSTEM_HAS_MOVE}
{$define FPC_SYSTEM_FPC_MOVE}
procedure Move_pld(const source;var dest;count:longint);assembler;nostackframe;
asm
  pld [r0]
  pld [r1]
  // count <=0 ?
  cmp r2,#0
  movle pc,lr
  // overlap?
  cmp r1,r0
  bls .Lnooverlap
  add r3,r0,r2
  cmp r3,r1
  bls .Lnooverlap
  // overlap, copy backward
.Loverlapped:
  subs r2,r2,#1
  ldrb r3,[r0,r2]
  strb r3,[r1,r2]
  bne .Loverlapped
  mov pc,lr
.Lnooverlap:
  // less then 16 bytes to copy?
  cmp r2,#8
  // yes, the forget about the whole optimizations
  // and do a bytewise copy
  blt .Lbyteloop

  // both aligned?
  orr r3,r0,r1
  tst r3,#3

  bne .Lbyteloop
(*
  // yes, then align
  // alignment to 4 byte boundries is enough
  ldrb ip,[r0],#1
  sub r2,r2,#1
  stb ip,[r1],#1
  tst r3,#2
  bne .Ldifferentaligned
  ldrh ip,[r0],#2
  sub r2,r2,#2
  sth ip,[r1],#2

.Ldifferentaligned
  // qword aligned?
  orrs r3,r0,r1
  tst r3,#7
  bne .Ldwordloop
*)
  pld [r0,#32]
  pld [r1,#32]
.Ldwordloop:
  sub r2,r2,#4
  ldr r3,[r0],#4
  // preload
  pld [r0,#64]
  pld [r1,#64]
  cmp r2,#4
  str r3,[r1],#4
  bcs .Ldwordloop
  cmp r2,#0
  moveq pc,lr
.Lbyteloop:
  subs r2,r2,#1
  ldrb r3,[r0],#1
  strb r3,[r1],#1
  bne .Lbyteloop
  mov pc,lr
end;

procedure Move_blended(const source;var dest;count:longint);assembler;nostackframe;
asm
  // count <=0 ?
  cmp r2,#0
  movle pc,lr
  // overlap?
  cmp r1,r0
  bls .Lnooverlap
  add r3,r0,r2
  cmp r3,r1
  bls .Lnooverlap
  // overlap, copy backward
.Loverlapped:
  subs r2,r2,#1
  ldrb r3,[r0,r2]
  strb r3,[r1,r2]
  bne .Loverlapped
  mov pc,lr
.Lnooverlap:
  // less then 16 bytes to copy?
  cmp r2,#8
  // yes, the forget about the whole optimizations
  // and do a bytewise copy
  blt .Lbyteloop

  // both aligned?
  orr r3,r0,r1
  tst r3,#3

  bne .Lbyteloop
(*
  // yes, then align
  // alignment to 4 byte boundries is enough
  ldrb ip,[r0],#1
  sub r2,r2,#1
  stb ip,[r1],#1
  tst r3,#2
  bne .Ldifferentaligned
  ldrh ip,[r0],#2
  sub r2,r2,#2
  sth ip,[r1],#2

.Ldifferentaligned
  // qword aligned?
  orrs r3,r0,r1
  tst r3,#7
  bne .Ldwordloop
*)
.Ldwordloop:
  sub r2,r2,#4
  ldr r3,[r0],#4
  cmp r2,#4
  str r3,[r1],#4
  bcs .Ldwordloop
  cmp r2,#0
  moveq pc,lr
.Lbyteloop:
  subs r2,r2,#1
  ldrb r3,[r0],#1
  strb r3,[r1],#1
  bne .Lbyteloop
  mov pc,lr
end;


procedure Move(const source;var dest;count:longint);[public, alias: 'FPC_MOVE'];assembler;nostackframe;
asm
  ldr ip,.Lmoveproc
  ldr pc,[ip]
.Lmoveproc:
  .long moveproc
end;

{$endif FPC_SYSTEM_HAS_MOVE}

var
  fpc_system_lock: longint; export name 'fpc_system_lock';

function InterLockedDecrement (var Target: longint) : longint; assembler; nostackframe;
asm
// lock
  ldr r3, .Lfpc_system_lock
  mov r1, #1
.Lloop:
  swp r2, r1, [r3]
  cmp r2, #0
  bne .Lloop
// do the job
  ldr r1, [r0]
  sub r1, r1, #1
  str r1, [r0]
  mov r0, r1
// unlock and return
  str r2, [r3]
  mov pc, lr

.Lfpc_system_lock:
  .long fpc_system_lock
end;


function InterLockedIncrement (var Target: longint) : longint; assembler; nostackframe;
asm
// lock
  ldr r3, .Lfpc_system_lock
  mov r1, #1
.Lloop:
  swp r2, r1, [r3]
  cmp r2, #0
  bne .Lloop
// do the job
  ldr r1, [r0]
  add r1, r1, #1
  str r1, [r0]
  mov r0, r1
// unlock and return
  str r2, [r3]
  mov pc, lr

.Lfpc_system_lock:
  .long fpc_system_lock
end;


function InterLockedExchange (var Target: longint;Source : longint) : longint; assembler; nostackframe;
asm
  swp r1, r1, [r0]
  mov r0,r1
end;

function InterLockedExchangeAdd (var Target: longint;Source : longint) : longint; assembler; nostackframe;
asm
// lock
  ldr r3, .Lfpc_system_lock
  mov r2, #1
.Lloop:
  swp r2, r2, [r3]
  cmp r2, #0
  bne .Lloop
// do the job
  ldr r2, [r0]
  add r1, r1, r2
  str r1, [r0]
  mov r0, r2
// unlock and return
  mov r2, #0
  str r2, [r3]
  mov pc, lr

.Lfpc_system_lock:
  .long fpc_system_lock
end;


function InterlockedCompareExchange(var Target: longint; NewValue: longint; Comperand: longint): longint; assembler; nostackframe;
asm
// lock
  ldr r12, .Lfpc_system_lock
  mov r3, #1
.Lloop:
  swp r3, r3, [r12]
  cmp r3, #0
  bne .Lloop
// do the job
  ldr r3, [r0]
  cmp r3, r2
  streq r1, [r0]
  mov r0, r3
// unlock and return
  mov r3, #0
  str r3, [r12]
  mov pc, lr

.Lfpc_system_lock:
  .long fpc_system_lock
end;

{$define FPC_SYSTEM_HAS_DECLOCKED_LONGINT}
function declocked(var l: longint) : boolean; inline;
begin
  Result:=InterLockedDecrement(l) = 0;
end;

{$define FPC_SYSTEM_HAS_INCLOCKED_LONGINT}
procedure inclocked(var l: longint); inline;
begin
  InterLockedIncrement(l);
end;

procedure fpc_cpucodeinit;
begin
  cpu_has_edsp:=true;
  in_edsp_test:=true;
  asm
    pld [r0]
  end;
  in_edsp_test:=false;
{$ifdef FPC_SYSTEM_FPC_MOVE}
  if cpu_has_edsp then
    moveproc:=@move_pld
  else
    moveproc:=@move_blended;
{$endif FPC_SYSTEM_FPC_MOVE}
end;