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/* Generic unsigned 32 bit division implementation.

   Copyright (C) 2009, 2011 Free Software Foundation, Inc.

   Contributed by Embecosm on behalf of Adapteva, Inc.

This file is part of GCC.

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/>.  */

typedef union { unsigned int i; float f; } fu;

unsigned int __udivsi3 (unsigned int a, unsigned int b);

unsigned int

__udivsi3 (unsigned int a, unsigned int b)

{

  unsigned int d, t, s0, s1, s2, r0, r1;

  fu u0, u1, u2,  u1b, u2b;

  if (b > a)

    return 0;

  if ((int) b < 0)

    return 1;

  /* Assuming B is nonzero, compute S0 such that 0 <= S0,

     (B << S0+1) does not overflow,

     A < 4.01 * (B << S0), with S0 choosen as small as possible

     without taking to much time calculating.  */

#ifdef CONVERT_UNSIGNED

  u0.f = a;

  u1.f = b;

#else /* !CONVERT_UNSIGNED */

  u0.f = (int) a;

  u1.f = (int) b;

#ifdef CONCISE

  if (a < 0)

    u0.i = (a >> 8) - 0x00800000 + 0x3f800000 + (31 << 23);

#else /* To use flag seting / cmove, this can be written as:  */

 {

  unsigned c = 0xff800000 - 0x4f000000;

  t = (int)a >> 8;

  if (t >= c)

    u0.i = (t - c);

 }

#endif

#endif /* !CONVERT_UNSIGNED */

  s0 = u0.i + 1 /* Compensate for rounding errors.  */

            - 0x00800000 /* adjust by one */ ;

  s0 = s0 - u1.i;

  s0 = (int)s0 >= 0 ? s0 : 0;

  s0 >>= 23;

  b <<= s0;

  r1 = 0;

  r0 = 1 << s0;

  a = ((t=a) - b);

  if (a <= t)

    {

      r1 += r0;

      a = ((t=a) - b);

      if (a <= t)

        do {

          r1 += r0;

          a = ((t=a) - b);

        } while (a <= t);

    }

  a += b;

  d = b - 1;

#define STEP(n) case n: a += a; t = a - d; if (t <= a) a = t;

  switch (s0)

    {

    STEP (31)

    STEP (30)

    STEP (29)

    STEP (28)

    STEP (27)

    STEP (26)

    STEP (25)

    STEP (24)

    STEP (23)

    STEP (22)

    STEP (21)

    STEP (20)

    STEP (19)

    STEP (18)

    STEP (17)

    STEP (16)

    STEP (15)

    STEP (14)

    STEP (13)

    STEP (12)

    STEP (11)

    STEP (10)

    STEP (9)

    STEP (8)

    STEP (7)

    STEP (6)

    STEP (5)

    STEP (4)

    STEP (3)

    STEP (2)

    STEP (1)

    case 0: ;

    }

  r0 = r1 | (r0-1 & a);

  return r0;

}