Subversion Repositories openrisc_2011-10-31

; libgcc routines for ARC cpu.

/* Copyright (C) 1995, 1997,2004, 2009 Free Software Foundation, Inc.

This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.

This file 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.  See the GNU
General Public License for more details.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

#ifdef  L_mulsi3
        .section .text
        .align 4

#ifdef __base__
        .cpu base
        .global ___mulsi3
___mulsi3:

/* This the simple version.

  while (a) 
    {
      if (a & 1)
        r += b;
      a >>= 1;
      b <<= 1;
    }
*/
        mov r2,0                ; Accumulate result here.
.Lloop:
        sub.f 0,r0,0            ; while (a)
        nop
        beq.nd .Ldone
        and.f 0,r0,1            ; if (a & 1)
        add.nz r2,r2,r1         ; r += b
        lsr r0,r0               ; a >>= 1
        b.d .Lloop
        lsl r1,r1               ; b <<= 1
.Ldone:
        j.d blink
        mov r0,r2
#endif

#endif /* L_mulsi3 */

#ifdef  L_umulsidi3
        .section .text
        .align 4

#ifdef __base__
        .cpu base
        .global ___umulsidi3
___umulsidi3:

/* This the simple version.

  while (a) 
    {
      if (a & 1)
        r += b;
      a >>= 1;
      b <<= 1;
    }
*/
        mov r2,0                ; Top part of b.
        mov r3,0                ; Accumulate result here.
        mov r4,0
.Lloop:
        sub.f 0,r0,0            ; while (a)
        nop
        beq.nd .Ldone
        and.f 0,r0,1            ; if (a & 1)
        sub.f 0,r0,0
        nop
        beq .Ldontadd
        add.f r4,r4,r1          ; r += b
        adc   r3,r3,r2
.Ldontadd:
        lsr r0,r0               ; a >>= 1
        lsl.f r1,r1             ; b <<= 1
        b.d .Lloop
        rlc r2,r2
.Ldone:
#ifdef __big_endian__
        mov r1,r4
        j.d blink
        mov r0,r3
#else
        mov r0,r4
        j.d blink
        mov r1,r3
#endif
#endif

#endif /* L_umulsidi3 */

#ifdef L_divmod_tools

; Utilities used by all routines.

        .section .text
        .align 4

; inputs: r0 = numerator, r1 = denominator
; outputs: positive r0/r1,
;          r6.bit1 = sign of numerator, r6.bit0 = sign of result

        .global ___divnorm
___divnorm:
        mov r6,0                ; keep sign in r6
        sub.f 0,r0,0            ; is numerator -ve?
        sub.lt r0,0,r0          ; negate numerator
        mov.lt r6,3             ; sign is -ve
        sub.f 0,r1,0            ; is denominator -ve?
        sub.lt r1,0,r1          ; negate denominator
        xor.lt r6,r6,1          ; toggle sign
        j.nd blink

/*
unsigned long
udivmodsi4(int modwanted, unsigned long num, unsigned long den)
{
  unsigned long bit = 1;
  unsigned long res = 0;

  while (den < num && bit && !(den & (1L<<31)))
    {
      den <<=1;
      bit <<=1;
    }
  while (bit)
    {
      if (num >= den)
        {
          num -= den;
          res |= bit;
        }
      bit >>=1;
      den >>=1;
    }
  if (modwanted) return num;
  return res;
}
*/

; inputs: r0 = numerator, r1 = denominator
; outputs: r0 = quotient, r1 = remainder, r2/r3 trashed

        .global ___udivmodsi4
___udivmodsi4:
        mov r2,1                ; bit = 1
        mov r3,0                ; res = 0
.Lloop1:
        sub.f 0,r1,r0           ; while (den < num
        nop
        bnc.nd .Lloop2
        sub.f 0,r2,0            ; && bit
        nop
        bz.nd .Lloop2
        lsl.f 0,r1              ; && !(den & (1<<31))
        nop
        bc.nd .Lloop2
        lsl r1,r1               ; den <<= 1
        b.d .Lloop1
        lsl r2,r2               ; bit <<= 1
.Lloop2:
        sub.f 0,r2,0            ; while (bit)
        nop
        bz.nd .Ldivmodend
        sub.f 0,r0,r1           ; if (num >= den)
        nop
        bc.nd .Lshiftdown
        sub r0,r0,r1            ; num -= den
        or r3,r3,r2             ; res |= bit
.Lshiftdown:
        lsr r2,r2               ; bit >>= 1
        b.d .Lloop2
        lsr r1,r1               ; den >>= 1
.Ldivmodend:
        mov r1,r0               ; r1 = mod
        j.d blink
        mov r0,r3               ; r0 = res

#endif

#ifdef  L_udivsi3
        .section .text
        .align 4

#ifdef __base__
        .cpu base
        .global ___udivsi3
___udivsi3:
        mov r7,blink
        bl.nd ___udivmodsi4
        j.nd r7
#endif

#endif /* L_udivsi3 */

#ifdef  L_divsi3
        .section .text
        .align 4

#ifdef __base__
        .cpu base
        .global ___divsi3
___divsi3:
        mov r7,blink
        bl.nd ___divnorm
        bl.nd ___udivmodsi4
        and.f 0,r6,1
        sub.nz r0,0,r0          ; cannot go in delay slot, has limm value
        j.nd r7
#endif

#endif /* L_divsi3 */

#ifdef  L_umodsi3
        .section .text
        .align 4

#ifdef __base__
        .cpu base
        .global ___umodsi3
___umodsi3:
        mov r7,blink
        bl.nd ___udivmodsi4
        j.d r7
        mov r0,r1
#endif

#endif /* L_umodsi3 */

#ifdef  L_modsi3
        .section .text
        .align 4

#ifdef __base__
        .cpu base
        .global ___modsi3
___modsi3:
        mov r7,blink
        bl.nd ___divnorm
        bl.nd ___udivmodsi4
        and.f 0,r6,2
        sub.nz r1,0,r1
        j.d r7
        mov r0,r1
#endif

#endif /* L_modsi3 */