/* Internal function for converting integers to ASCII.

   Copyright (C) 1994-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Torbjorn Granlund <tege@matematik.su.se>

   and Ulrich Drepper <drepper@gnu.org>.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <gmp-mparam.h>

#include <gmp.h>

#include <limits.h>

#include <stdlib/gmp-impl.h>

#include <stdlib/longlong.h>

#include <_itowa.h>

/* Canonize environment.  For some architectures not all values might

   be defined in the GMP header files.  */

#ifndef UMUL_TIME

# define UMUL_TIME 1

#endif

#ifndef UDIV_TIME

# define UDIV_TIME 3

#endif

/* Control memory layout.  */

#ifdef PACK

# undef PACK

# define PACK __attribute__ ((packed))

#else

# define PACK

#endif

/* Declare local types.  */

struct base_table_t

{

#if (UDIV_TIME > 2 * UMUL_TIME)

  mp_limb_t base_multiplier;

#endif

  char flag;

  char post_shift;

#if BITS_PER_MP_LIMB == 32

  struct

    {

      char normalization_steps;

      char ndigits;

      mp_limb_t base PACK;

#if UDIV_TIME > 2 * UMUL_TIME

      mp_limb_t base_ninv PACK;

#endif

    } big;

#endif

};

/* To reduce the memory needed we include some fields of the tables

   only conditionally.  */

#if UDIV_TIME > 2 * UMUL_TIME

# define SEL1(X) X,

# define SEL2(X) ,X

#else

# define SEL1(X)

# define SEL2(X)

#endif

/* Factor table for the different bases.  */

extern const struct base_table_t _itoa_base_table[] attribute_hidden;

/* Lower-case digits.  */

extern const wchar_t _itowa_lower_digits[] attribute_hidden;

/* Upper-case digits.  */

extern const wchar_t _itowa_upper_digits[] attribute_hidden;

#if _ITOA_NEEDED

wchar_t *

_itowa (unsigned long long int value, wchar_t *buflim, unsigned int base,

	int upper_case)

{

  const wchar_t *digits = (upper_case

			   ? _itowa_upper_digits : _itowa_lower_digits);

  wchar_t *bp = buflim;

  const struct base_table_t *brec = &_itoa_base_table[base - 2];

  switch (base)

    {

# define RUN_2N(BITS) \

      do								      \

	{								      \

	  /* `unsigned long long int' always has 64 bits.  */		      \

	  mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB);		      \

									      \

	  if (BITS_PER_MP_LIMB == 32)					      \

	    {								      \

	      if (work_hi != 0)						      \

		{							      \

		  mp_limb_t work_lo;					      \

		  int cnt;						      \

									      \

		  work_lo = value & 0xfffffffful;			      \

		  for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt)	      \

		    {							      \

		      *--bp = digits[work_lo & ((1ul << BITS) - 1)];	      \

		      work_lo >>= BITS;					      \

		    }							      \

		  if (BITS_PER_MP_LIMB % BITS != 0)			      \

		    {							      \

		      work_lo						      \

			|= ((work_hi					      \

			     & ((1 << (BITS - BITS_PER_MP_LIMB%BITS))	      \

				- 1))					      \

			    << BITS_PER_MP_LIMB % BITS);		      \

		      work_hi >>= BITS - BITS_PER_MP_LIMB % BITS;	      \

		      if (work_hi == 0)					      \

			work_hi = work_lo;				      \

		      else						      \

			*--bp = digits[work_lo];			      \

		    }							      \

		}							      \

	      else							      \

		work_hi = value & 0xfffffffful;				      \

	    }								      \

	  do								      \

	    {								      \

	      *--bp = digits[work_hi & ((1 << BITS) - 1)];		      \

	      work_hi >>= BITS;						      \

	    }								      \

	  while (work_hi != 0);						      \

	}								      \

      while (0)

    case 8:

      RUN_2N (3);

      break;

    case 16:

      RUN_2N (4);

      break;

    default:

      {

# if BITS_PER_MP_LIMB == 64

	mp_limb_t base_multiplier = brec->base_multiplier;

	if (brec->flag)

	  while (value != 0)

	    {

	      mp_limb_t quo, rem, x;

	      mp_limb_t dummy __attribute__ ((unused));

	      umul_ppmm (x, dummy, value, base_multiplier);

	      quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);

	      rem = value - quo * base;

	      *--bp = digits[rem];

	      value = quo;

	    }

	else

	  while (value != 0)

	    {

	      mp_limb_t quo, rem, x;

	      mp_limb_t dummy __attribute__ ((unused));

	      umul_ppmm (x, dummy, value, base_multiplier);

	      quo = x >> brec->post_shift;

	      rem = value - quo * base;

	      *--bp = digits[rem];

	      value = quo;

	    }

# endif

# if BITS_PER_MP_LIMB == 32

	mp_limb_t t[3];

	int n;

	/* First convert x0 to 1-3 words in base s->big.base.

	   Optimize for frequent cases of 32 bit numbers.  */

	if ((mp_limb_t) (value >> 32) >= 1)

	  {

# if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION

	    int big_normalization_steps = brec->big.normalization_steps;

	    mp_limb_t big_base_norm

	      = brec->big.base << big_normalization_steps;

# endif

	    if ((mp_limb_t) (value >> 32) >= brec->big.base)

	      {

		mp_limb_t x1hi, x1lo, r;

		/* If you want to optimize this, take advantage of

		   that the quotient in the first udiv_qrnnd will

		   always be very small.  It might be faster just to

		   subtract in a tight loop.  */

# if UDIV_TIME > 2 * UMUL_TIME

		mp_limb_t x, xh, xl;

		if (big_normalization_steps == 0)

		  xh = 0;

		else

		  xh = (mp_limb_t) (value >> (64 - big_normalization_steps));

		xl = (mp_limb_t) (value >> (32 - big_normalization_steps));

		udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,

				   brec->big.base_ninv);

		xl = ((mp_limb_t) value) << big_normalization_steps;

		udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,

				   brec->big.base_ninv);

		t[2] = x >> big_normalization_steps;

		if (big_normalization_steps == 0)

		  xh = x1hi;

		else

		  xh = ((x1hi << big_normalization_steps)

			| (x1lo >> (32 - big_normalization_steps)));

		xl = x1lo << big_normalization_steps;

		udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,

				   brec->big.base_ninv);

		t[1] = x >> big_normalization_steps;

# elif UDIV_NEEDS_NORMALIZATION

		mp_limb_t x, xh, xl;

		if (big_normalization_steps == 0)

		  xh = 0;

		else

		  xh = (mp_limb_t) (value >> 64 - big_normalization_steps);

		xl = (mp_limb_t) (value >> 32 - big_normalization_steps);

		udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);

		xl = ((mp_limb_t) value) << big_normalization_steps;

		udiv_qrnnd (x1lo, x, r, xl, big_base_norm);

		t[2] = x >> big_normalization_steps;

		if (big_normalization_steps == 0)

		  xh = x1hi;

		else

		  xh = ((x1hi << big_normalization_steps)

			| (x1lo >> 32 - big_normalization_steps));

		xl = x1lo << big_normalization_steps;

		udiv_qrnnd (t[0], x, xh, xl, big_base_norm);

		t[1] = x >> big_normalization_steps;

# else

		udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),

			    brec->big.base);

		udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);

		udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);

# endif

		n = 3;

	      }

	    else

	      {

# if UDIV_TIME > 2 * UMUL_TIME

		mp_limb_t x;

		value <<= brec->big.normalization_steps;

		udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),

				   (mp_limb_t) value, big_base_norm,

				   brec->big.base_ninv);

		t[1] = x >> brec->big.normalization_steps;

# elif UDIV_NEEDS_NORMALIZATION

		mp_limb_t x;

		value <<= big_normalization_steps;

		udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),

			    (mp_limb_t) value, big_base_norm);

		t[1] = x >> big_normalization_steps;

# else

		udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),

			    (mp_limb_t) value, brec->big.base);

# endif

		n = 2;

	      }

	  }

	else

	  {

	    t[0] = value;

	    n = 1;

	  }

	/* Convert the 1-3 words in t[], word by word, to ASCII.  */

	do

	  {

	    mp_limb_t ti = t[--n];

	    int ndig_for_this_limb = 0;

# if UDIV_TIME > 2 * UMUL_TIME

	    mp_limb_t base_multiplier = brec->base_multiplier;

	    if (brec->flag)

	      while (ti != 0)

		{

		  mp_limb_t quo, rem, x;

		  mp_limb_t dummy __attribute__ ((unused));

		  umul_ppmm (x, dummy, ti, base_multiplier);

		  quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);

		  rem = ti - quo * base;

		  *--bp = digits[rem];

		  ti = quo;

		  ++ndig_for_this_limb;

		}

	    else

	      while (ti != 0)

		{

		  mp_limb_t quo, rem, x;

		  mp_limb_t dummy __attribute__ ((unused));

		  umul_ppmm (x, dummy, ti, base_multiplier);

		  quo = x >> brec->post_shift;

		  rem = ti - quo * base;

		  *--bp = digits[rem];

		  ti = quo;

		  ++ndig_for_this_limb;

		}

# else

	    while (ti != 0)

	      {

		mp_limb_t quo, rem;

		quo = ti / base;

		rem = ti % base;

		*--bp = digits[rem];

		ti = quo;

		++ndig_for_this_limb;

	      }

# endif

	    /* If this wasn't the most significant word, pad with zeros.  */

	    if (n != 0)

	      while (ndig_for_this_limb < brec->big.ndigits)

		{

		  *--bp = '0';

		  ++ndig_for_this_limb;

		}

	  }

	while (n != 0);

# endif

      }

      break;

    }

  return bp;

}

#endif