Subversion Repositories openrisc_2011-10-31

/*

FUNCTION

        <<strtoufix16>>, <<strtoufix32>>, <<strtoufix64>>---string to signed fixed point

INDEX

        strtoufix16

INDEX

        strtoufix32

INDEX

        strtoufix64

INDEX

        _strtoufix16_r

INDEX

        _strtoufix32_r

INDEX

        _strtoufix64_r

ANSI_SYNOPSIS

        #include <stdlib.h>

        __uint16_t strtoufix16 (const char *<[s]>, char **<[ptr]>);

        __uint32_t strtoufix32 (const char *<[s]>, char **<[ptr]>);

        __uint64_t strtoufix64 (const char *<[s]>, char **<[ptr]>);

        __uint16_t _strtoufix16_r (void *<[reent]>,

                       const char *<[s]>, char **<[ptr]>);

        __uint32_t _strtoufix32_r (void *<[reent]>,

                       const char *<[s]>, char **<[ptr]>);

        __uint64_t _strtoufix64_r (void *<[reent]>,

                       const char *<[s]>, char **<[ptr]>);

TRAD_SYNOPSIS

        #include <stdlib.h>

        __uint16_t strtoufix16 (<[s]>, <[ptr]>)

        char *<[s]>;

        char **<[ptr]>;

        __uint32_t strtoufix32 (<[s]>, <[ptr]>)

        char *<[s]>;

        char **<[ptr]>;

        __uint64_t strtoufix64 (<[s]>, <[ptr]>)

        char *<[s]>;

        char **<[ptr]>;

        __uint16_t _strtoufix16_r (<[reent]>, <[s]>, <[ptr]>)

        char *<[reent]>;

        char *<[s]>;

        char **<[ptr]>;

        __uint32_t _strtoufix32_r (<[reent]>, <[s]>, <[ptr]>)

        char *<[reent]>;

        char *<[s]>;

        char **<[ptr]>;

        __uint64_t _strtoufix64_r (<[reent]>, <[s]>, <[ptr]>)

        char *<[reent]>;

        char *<[s]>;

        char **<[ptr]>;

DESCRIPTION

        The function <<strtoufix16>> converts the string <<*<[s]>>> to

        a fixed-point 16-bits fraction representation.  The function

        follows the same rules as <<strtod>>.

        The substring converted is the longest initial

        subsequence of <[s]>, beginning with the first

        non-whitespace character, that has the format:

        .[+|-]<[digits]>[.][<[digits]>][(e|E)[+|-]<[digits]>]

        The substring contains no characters if <[s]> is empty, consists

        entirely of whitespace, or if the first non-whitespace

        character is something other than <<+>>, <<->>, <<.>>, or a

        digit. If the substring is empty, no conversion is done, and

        the value of <[s]> is stored in <<*<[ptr]>>>.  Otherwise,

        the substring is converted, and a pointer to the final string

        (which will contain at least the terminating null character of

        <[s]>) is stored in <<*<[ptr]>>>.  If you want no

        assignment to <<*<[ptr]>>>, pass a null pointer as <[ptr]>.

        <<strtoufix32>> is identical to <<strtoufix16>> except that it

        converts to fixed-point 32-bit fraction representation.

        <<strtoufix64>> is also similar, except that it converts

        to fixed-point 64-bit fraction.

        The alternate functions <<_strtoufix16_r>>, <<_strtoufix32_r>>,

        and <<_strtoufix64_r>> are reentrant versions.

        The extra argument <[reent]> is a pointer to a reentrancy structure.

RETURNS

        The functions return the converted substring value, if any.  If

        no conversion can be performed, then 0 is returned.  If the converted

        value is a NaN, 0 is returned and errno is set to <<EDOM>>.

        If the converted value exceeds the maximum positive unsigned fixed-point value,

        the output value is saturated to the maximum value and <<ERANGE>> is stored in

        errno.  If the converted value is less than 0, then the output is saturated to 0

        and <<ERANGE>> is stored in errno.  Otherwise, the converted value is returned in the

        specified fixed-point format.

PORTABILITY

        <<strtoufix16>>, <<strtoufix32>>, and <<strtoufix64>> are non-standard.

        The OS subroutines of <<strtod>> are required.

*/

#ifdef __SPE__

#include <_ansi.h>

#include <limits.h>

#include <errno.h>

#include <stdlib.h>

#include <reent.h>

#include "vfieeefp.h"

/*

 * Convert a string to a fixed-point 16-bit value.

 *

 * Ignores `locale' stuff.

 */

__uint16_t

_DEFUN (_strtoufix16_r, (rptr, nptr, endptr),

        struct _reent *rptr _AND

        _CONST char *nptr _AND

        char **endptr)

{

  union double_union dbl;

  unsigned long tmp, tmp2, result;

  int exp, negexp;

  dbl.d = _strtod_r (rptr, nptr, endptr);

  /* treat NAN as domain error, +/- infinity as saturation */

  if (!finite(dbl.d))

    {

      if (isnan (dbl.d))

        {

          rptr->_errno = EDOM;

          return 0;

        }

      rptr->_errno = ERANGE;

      if (word0(dbl) & Sign_bit)

        return 0;

      return USHRT_MAX;

    }

  /* check for normal saturation */

  if (dbl.d >= 1.0)

    {

      rptr->_errno = ERANGE;

      return USHRT_MAX;

    }

  else if (dbl.d < 0)

    {

      rptr->_errno = ERANGE;

      return 0;

    }

  /* otherwise we have normal postive number in range */

  /* strip off exponent */

  exp = ((word0(dbl) & Exp_mask) >> Exp_shift) - Bias;

  negexp = -exp;

  if (negexp > 16)

    return 0;

  /* add in implicit normalized bit */

  tmp = word0(dbl) | Exp_msk1;

  /* remove exponent and sign */

  tmp <<= Ebits;

  /* perform rounding */

  tmp2 = tmp + (1 << (negexp + 14));

  result = tmp2 >> (negexp + 15);

  /* if rounding causes carry, must add carry bit in */

  if (tmp2 < tmp)

    {

      if (negexp == 0)

        {

          /* we have overflow which means saturation */

          rptr->_errno = ERANGE;

          return USHRT_MAX;

        }

      result |= (1 << (16 - negexp));

    }

  return (__uint16_t)result;

}

#ifndef _REENT_ONLY

__uint16_t

_DEFUN (strtoufix16, (s, ptr, base),

        _CONST char *s _AND

        char **ptr)

{

  return _strtoufix16_r (_REENT, s, ptr);

}

#endif

#endif /* __SPE__ */