root/ext/bigdecimal/bigdecimal.c

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DEFINITIONS

This source file includes following definitions.
  1. Init_BigDecimal
  2. BigDecimal_version
  3. BigDecimal_delete
  4. ToValue
  5. GetVpValue
  6. BigDecimal_double_fig
  7. BigDecimal_prec
  8. BigDecimal_hash
  9. BigDecimal_dump
  10. BigDecimal_load
  11. BigDecimal_mode
  12. GetAddSubPrec
  13. GetPositiveInt
  14. VpNewRbClass
  15. VpCreateRbObject
  16. BigDecimal_IsNaN
  17. BigDecimal_IsInfinite
  18. BigDecimal_IsFinite
  19. BigDecimal_check_num
  20. BigDecimal_to_i
  21. BigDecimal_to_f
  22. BigDecimal_to_r
  23. BigDecimal_coerce
  24. BigDecimal_uplus
  25. BigDecimal_add
  26. BigDecimal_sub
  27. BigDecimalCmp
  28. BigDecimal_zero
  29. BigDecimal_nonzero
  30. BigDecimal_comp
  31. BigDecimal_eq
  32. BigDecimal_lt
  33. BigDecimal_le
  34. BigDecimal_gt
  35. BigDecimal_ge
  36. BigDecimal_neg
  37. BigDecimal_mult
  38. BigDecimal_divide
  39. BigDecimal_div
  40. BigDecimal_DoDivmod
  41. BigDecimal_mod
  42. BigDecimal_divremain
  43. BigDecimal_remainder
  44. BigDecimal_divmod
  45. BigDecimal_div2
  46. BigDecimal_add2
  47. BigDecimal_sub2
  48. BigDecimal_mult2
  49. BigDecimal_abs
  50. BigDecimal_sqrt
  51. BigDecimal_fix
  52. BigDecimal_round
  53. BigDecimal_truncate
  54. BigDecimal_frac
  55. BigDecimal_floor
  56. BigDecimal_ceil
  57. BigDecimal_to_s
  58. BigDecimal_split
  59. BigDecimal_exponent
  60. BigDecimal_inspect
  61. BigDecimal_power
  62. BigDecimal_global_new
  63. BigDecimal_new
  64. BigDecimal_limit
  65. BigDecimal_sign
  66. Init_bigdecimal
  67. VpMemAlloc
  68. VpFree
  69. VpGetException
  70. VpSetException
  71. VpGetPrecLimit
  72. VpSetPrecLimit
  73. VpGetRoundMode
  74. VpIsRoundMode
  75. VpSetRoundMode
  76. Zero
  77. One
  78. VpBaseFig
  79. VpDblFig
  80. VpBaseVal
  81. VpGetDoubleNaN
  82. VpGetDoublePosInf
  83. VpGetDoubleNegInf
  84. VpGetDoubleNegZero
  85. VpIsNegDoubleZero
  86. VpException
  87. VpIsDefOP
  88. VpNumOfChars
  89. VpInit
  90. VpOne
  91. AddExponent
  92. VpAlloc
  93. VpAsgn
  94. VpAddSub
  95. VpAddAbs
  96. VpSubAbs
  97. VpSetPTR
  98. VpMult
  99. VpDivd
  100. VpNmlz
  101. VpComp
  102. VPrint
  103. VpFormatSt
  104. VpExponent10
  105. VpSzMantissa
  106. VpToSpecialString
  107. VpToString
  108. VpToFString
  109. VpCtoV
  110. VpVtoD
  111. VpDtoV
  112. VpItoV
  113. VpSqrt
  114. VpMidRound
  115. VpLeftRound
  116. VpActiveRound
  117. VpLimitRound
  118. VpInternalRound
  119. VpRdup
  120. VpFrac
  121. VpPower
  122. VpVarCheck

/*
 *
 * Ruby BigDecimal(Variable decimal precision) extension library.
 *
 * Copyright(C) 2002 by Shigeo Kobayashi(shigeo@tinyforest.gr.jp)
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Artistic License, as specified in the README file
 * of this BigDecimal distribution.
 *
 *  NOTE: Change log in this source removed to reduce source code size. 
 *        See rev. 1.25 if needed.
 *
 */

#include "ruby/ruby.h"
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <float.h>
#include <math.h>
#include "math.h"

#ifdef HAVE_IEEEFP_H
#include <ieeefp.h>
#endif
 
/* #define ENABLE_NUMERIC_STRING */

VALUE rb_cBigDecimal;

#include "bigdecimal.h"

/* MACRO's to guard objects from GC by keeping them in stack */
#define ENTER(n) volatile VALUE vStack[n];int iStack=0
#define PUSH(x)  vStack[iStack++] = (unsigned long)(x);
#define SAVE(p)  PUSH(p->obj);
#define GUARD_OBJ(p,y) {p=y;SAVE(p);}

/*
 * ================== Ruby Interface part ==========================
 */
#define DoSomeOne(x,y,f) rb_num_coerce_bin(x,y,f)

#if 0
/* BigDecimal provides arbitrary-precision floating point decimal arithmetic.
 *
 * Copyright (C) 2002 by Shigeo Kobayashi <shigeo@tinyforest.gr.jp>.
 * You may distribute under the terms of either the GNU General Public
 * License or the Artistic License, as specified in the README file
 * of the BigDecimal distribution.
 *
 * Documented by mathew <meta@pobox.com>.
 *
 * = Introduction
 *
 * Ruby provides built-in support for arbitrary precision integer arithmetic.
 * For example:
 *
 * 42**13   ->   1265437718438866624512
 *
 * BigDecimal provides similar support for very large or very accurate floating
 * point numbers.
 *
 * Decimal arithmetic is also useful for general calculation, because it
 * provides the correct answers people expect--whereas normal binary floating
 * point arithmetic often introduces subtle errors because of the conversion
 * between base 10 and base 2. For example, try:
 *
 *   sum = 0
 *   for i in (1..10000)
 *     sum = sum + 0.0001
 *   end
 *   print sum
 *
 * and contrast with the output from:
 *
 *   require 'bigdecimal'
 *
 *   sum = BigDecimal.new("0")
 *   for i in (1..10000)
 *     sum = sum + BigDecimal.new("0.0001")
 *   end
 *   print sum
 *
 * Similarly:
 *
 * (BigDecimal.new("1.2") - BigDecimal("1.0")) == BigDecimal("0.2") -> true
 *
 * (1.2 - 1.0) == 0.2 -> false
 *
 * = Special features of accurate decimal arithmetic
 *
 * Because BigDecimal is more accurate than normal binary floating point
 * arithmetic, it requires some special values.
 *
 * == Infinity
 *
 * BigDecimal sometimes needs to return infinity, for example if you divide
 * a value by zero.
 *
 * BigDecimal.new("1.0") / BigDecimal.new("0.0")  -> infinity
 *
 * BigDecimal.new("-1.0") / BigDecimal.new("0.0")  -> -infinity
 *
 * You can represent infinite numbers to BigDecimal using the strings
 * 'Infinity', '+Infinity' and '-Infinity' (case-sensitive)
 *
 * == Not a Number
 *
 * When a computation results in an undefined value, the special value NaN
 * (for 'not a number') is returned.
 *
 * Example:
 *
 * BigDecimal.new("0.0") / BigDecimal.new("0.0") -> NaN
 *
 * You can also create undefined values.  NaN is never considered to be the
 * same as any other value, even NaN itself:
 *
 * n = BigDecimal.new('NaN')
 *
 * n == 0.0 -> nil
 *
 * n == n -> nil
 *
 * == Positive and negative zero
 *
 * If a computation results in a value which is too small to be represented as
 * a BigDecimal within the currently specified limits of precision, zero must
 * be returned.
 *
 * If the value which is too small to be represented is negative, a BigDecimal
 * value of negative zero is returned. If the value is positive, a value of
 * positive zero is returned.
 *
 * BigDecimal.new("1.0") / BigDecimal.new("-Infinity") -> -0.0
 *
 * BigDecimal.new("1.0") / BigDecimal.new("Infinity") -> 0.0
 *
 * (See BigDecimal.mode for how to specify limits of precision.)
 *
 * Note that -0.0 and 0.0 are considered to be the same for the purposes of
 * comparison.
 *
 * Note also that in mathematics, there is no particular concept of negative 
 * or positive zero; true mathematical zero has no sign.
 */
void
Init_BigDecimal()
{
    /* This is a #if-ed out function to fool Rdoc into documenting the class. */
    /* The real init function is Init_bigdecimal() further down. */
}
#endif

/*
 * Returns the BigDecimal version number.
 *
 * Ruby 1.8.0 returns 1.0.0.
 * Ruby 1.8.1 thru 1.8.3 return 1.0.1.
 */
static VALUE
BigDecimal_version(VALUE self)
{
    /*
     * 1.0.0: Ruby 1.8.0
     * 1.0.1: Ruby 1.8.1
    */
    return rb_str_new2("1.0.1");
}

/*
 *   VP routines used in BigDecimal part 
 */
static unsigned short VpGetException(void);
static void  VpSetException(unsigned short f);
static void  VpInternalRound(Real *c,int ixDigit,U_LONG vPrev,U_LONG v);
static int   VpLimitRound(Real *c,U_LONG ixDigit);

/*
 *  **** BigDecimal part ****
 */

static void
BigDecimal_delete(Real *pv)
{
    VpFree(pv);
}

static VALUE
ToValue(Real *p)
{
    if(VpIsNaN(p)) {
        VpException(VP_EXCEPTION_NaN,"Computation results to 'NaN'(Not a Number)",0);
    } else if(VpIsPosInf(p)) {
        VpException(VP_EXCEPTION_INFINITY,"Computation results to 'Infinity'",0);
    } else if(VpIsNegInf(p)) {
        VpException(VP_EXCEPTION_INFINITY,"Computation results to '-Infinity'",0);
    }
    return p->obj;
}

static Real *
GetVpValue(VALUE v, int must)
{
    Real *pv;
    VALUE bg;
    char szD[128];

    switch(TYPE(v))
    {
    case T_DATA:
        if(RDATA(v)->dfree ==(void *) BigDecimal_delete) {
            Data_Get_Struct(v, Real, pv);
            return pv;
        } else {
            goto SomeOneMayDoIt;
        }
        break;
    case T_FIXNUM:
        sprintf(szD, "%ld", FIX2LONG(v));
        return VpCreateRbObject(VpBaseFig() * 2 + 1, szD);

#ifdef ENABLE_NUMERIC_STRING
    case T_STRING:
        SafeStringValue(v);
        return VpCreateRbObject(strlen(RSTRING_PTR(v)) + VpBaseFig() + 1,
                                RSTRING_PTR(v));
#endif /* ENABLE_NUMERIC_STRING */

    case T_BIGNUM:
        bg = rb_big2str(v, 10);
        return VpCreateRbObject(strlen(RSTRING_PTR(bg)) + VpBaseFig() + 1,
                                RSTRING_PTR(bg));
    default:
        goto SomeOneMayDoIt;
    }

SomeOneMayDoIt:
    if(must) {
        rb_raise(rb_eTypeError, "%s can't be coerced into BigDecimal",
                    rb_special_const_p(v)?
                    RSTRING_PTR(rb_inspect(v)):
                    rb_obj_classname(v)
                );
    }
    return NULL; /* NULL means to coerce */
}

/* call-seq:
 * BigDecimal.double_fig
 *
 * The BigDecimal.double_fig class method returns the number of digits a
 * Float number is allowed to have. The result depends upon the CPU and OS
 * in use.
 */
static VALUE
BigDecimal_double_fig(VALUE self)
{
    return INT2FIX(VpDblFig());
}

/* call-seq:
 * precs
 *
 * Returns an Array of two Integer values.
 *
 * The first value is the current number of significant digits in the 
 * BigDecimal. The second value is the maximum number of significant digits
 * for the BigDecimal.
 */
static VALUE
BigDecimal_prec(VALUE self)
{
    ENTER(1);
    Real *p;
    VALUE obj;

    GUARD_OBJ(p,GetVpValue(self,1));
    obj = rb_assoc_new(INT2NUM(p->Prec*VpBaseFig()),
                       INT2NUM(p->MaxPrec*VpBaseFig()));
    return obj;
}

static VALUE
BigDecimal_hash(VALUE self)
{
    ENTER(1);
    Real *p;
    U_LONG hash,i;

    GUARD_OBJ(p,GetVpValue(self,1));
    hash = (U_LONG)p->sign;
    /* hash!=2: the case for 0(1),NaN(0) or +-Infinity(3) is sign itself */
    if(hash==2) {
        for(i = 0; i < p->Prec;i++) {
            hash = 31 * hash + p->frac[i];
            hash ^= p->frac[i];
        }
        hash += p->exponent;
    }
    return INT2FIX(hash);
}

static VALUE
BigDecimal_dump(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *vp;
    char *psz;
    VALUE dummy;
    volatile VALUE dump;

    rb_scan_args(argc, argv, "01", &dummy);
    GUARD_OBJ(vp,GetVpValue(self,1));
    dump = rb_str_new(0,VpNumOfChars(vp,"E")+50);
    psz = RSTRING_PTR(dump);
    sprintf(psz,"%lu:",VpMaxPrec(vp)*VpBaseFig());
    VpToString(vp, psz+strlen(psz), 0, 0);
    rb_str_resize(dump, strlen(psz));
    return dump;
}

/*
 * Internal method used to provide marshalling support. See the Marshal module.
 */
static VALUE
BigDecimal_load(VALUE self, VALUE str)
{
    ENTER(2);
    Real *pv;
    unsigned char *pch;
    unsigned char ch;
    unsigned long m=0;

    SafeStringValue(str);
    pch = (unsigned char *)RSTRING_PTR(str);
    /* First get max prec */
    while((*pch)!=(unsigned char)'\0' && (ch=*pch++)!=(unsigned char)':') {
        if(!ISDIGIT(ch)) {
            rb_raise(rb_eTypeError, "load failed: invalid character in the marshaled string");
        }
        m = m*10 + (unsigned long)(ch-'0');
    }
    if(m>VpBaseFig()) m -= VpBaseFig();
    GUARD_OBJ(pv,VpNewRbClass(m,(char *)pch,self));
    m /= VpBaseFig();
    if(m && pv->MaxPrec>m) pv->MaxPrec = m+1;
    return ToValue(pv);
}

 /* call-seq:
  * BigDecimal.mode(mode, value)
  *
  * Controls handling of arithmetic exceptions and rounding. If no value
  * is supplied, the current value is returned.
  *
  * Six values of the mode parameter control the handling of arithmetic
  * exceptions:
  *
  * BigDecimal::EXCEPTION_NaN
  * BigDecimal::EXCEPTION_INFINITY
  * BigDecimal::EXCEPTION_UNDERFLOW
  * BigDecimal::EXCEPTION_OVERFLOW
  * BigDecimal::EXCEPTION_ZERODIVIDE
  * BigDecimal::EXCEPTION_ALL
  *
  * For each mode parameter above, if the value set is false, computation 
  * continues after an arithmetic exception of the appropriate type. 
  * When computation continues, results are as follows:
  *
  * EXCEPTION_NaN:: NaN
  * EXCEPTION_INFINITY:: +infinity or -infinity
  * EXCEPTION_UNDERFLOW:: 0
  * EXCEPTION_OVERFLOW:: +infinity or -infinity
  * EXCEPTION_ZERODIVIDE:: +infinity or -infinity
  *
  * One value of the mode parameter controls the rounding of numeric values:
  * BigDecimal::ROUND_MODE. The values it can take are:
  *
  * ROUND_UP:: round away from zero
  * ROUND_DOWN:: round towards zero (truncate)
  * ROUND_HALF_UP:: round up if the appropriate digit >= 5, otherwise truncate (default)
  * ROUND_HALF_DOWN:: round up if the appropriate digit >= 6, otherwise truncate
  * ROUND_HALF_EVEN:: round towards the even neighbor (Banker's rounding)
  * ROUND_CEILING:: round towards positive infinity (ceil)
  * ROUND_FLOOR:: round towards negative infinity (floor)
  *
  */
static VALUE
BigDecimal_mode(int argc, VALUE *argv, VALUE self)
{
    VALUE which;
    VALUE val;
    unsigned long f,fo;
 
    if(rb_scan_args(argc,argv,"11",&which,&val)==1) val = Qnil;

    Check_Type(which, T_FIXNUM);
    f = (unsigned long)FIX2INT(which);

    if(f&VP_EXCEPTION_ALL) {
        /* Exception mode setting */
        fo = VpGetException();
        if(val==Qnil) return INT2FIX(fo);
        if(val!=Qfalse && val!=Qtrue) {
            rb_raise(rb_eTypeError, "second argument must be true or false");
            return Qnil; /* Not reached */
        }
        if(f&VP_EXCEPTION_INFINITY) {
            VpSetException((unsigned short)((val==Qtrue)?(fo|VP_EXCEPTION_INFINITY):
                           (fo&(~VP_EXCEPTION_INFINITY))));
        }
        fo = VpGetException();
        if(f&VP_EXCEPTION_NaN) {
            VpSetException((unsigned short)((val==Qtrue)?(fo|VP_EXCEPTION_NaN):
                           (fo&(~VP_EXCEPTION_NaN))));
        }
        fo = VpGetException();
        if(f&VP_EXCEPTION_UNDERFLOW) {
            VpSetException((unsigned short)((val==Qtrue)?(fo|VP_EXCEPTION_UNDERFLOW):
                           (fo&(~VP_EXCEPTION_UNDERFLOW))));
        }
        fo = VpGetException();
        if(f&VP_EXCEPTION_ZERODIVIDE) {
            VpSetException((unsigned short)((val==Qtrue)?(fo|VP_EXCEPTION_ZERODIVIDE):
                           (fo&(~VP_EXCEPTION_ZERODIVIDE))));
        }
        fo = VpGetException();
        return INT2FIX(fo);
    }
    if(VP_ROUND_MODE==f) {
        /* Rounding mode setting */
        fo = VpGetRoundMode();
        if(val==Qnil) return INT2FIX(fo);
        Check_Type(val, T_FIXNUM);
        if(!VpIsRoundMode(FIX2INT(val))) {
            rb_raise(rb_eTypeError, "invalid rounding mode");
            return Qnil;
        }
        fo = VpSetRoundMode((unsigned long)FIX2INT(val));
        return INT2FIX(fo);
    }
    rb_raise(rb_eTypeError, "first argument for BigDecimal#mode invalid");
    return Qnil;
}

static U_LONG
GetAddSubPrec(Real *a, Real *b)
{
    U_LONG mxs;
    U_LONG mx = a->Prec;
    S_INT d;

    if(!VpIsDef(a) || !VpIsDef(b)) return (-1L);
    if(mx < b->Prec) mx = b->Prec;
    if(a->exponent!=b->exponent) {
        mxs = mx;
        d = a->exponent - b->exponent;
        if(d<0) d = -d;
        mx = mx+(U_LONG)d;
        if(mx<mxs) {
            return VpException(VP_EXCEPTION_INFINITY,"Exponent overflow",0);
        }
    }
    return mx;
}

static S_INT
GetPositiveInt(VALUE v)
{
    S_INT n;
    Check_Type(v, T_FIXNUM);
    n = FIX2INT(v);
    if(n < 0) {
        rb_raise(rb_eArgError, "argument must be positive");
    }
    return n;
}

VP_EXPORT Real *
VpNewRbClass(U_LONG mx, char *str, VALUE klass)
{
    Real *pv = VpAlloc(mx,str);
    pv->obj = (VALUE)Data_Wrap_Struct(klass, 0, BigDecimal_delete, pv);
    return pv;
}

VP_EXPORT Real *
VpCreateRbObject(U_LONG mx, const char *str)
{
    Real *pv = VpAlloc(mx,str);
    pv->obj = (VALUE)Data_Wrap_Struct(rb_cBigDecimal, 0, BigDecimal_delete, pv);
    return pv;
}

/* Returns True if the value is Not a Number */
static VALUE
BigDecimal_IsNaN(VALUE self)
{
    Real *p = GetVpValue(self,1);
    if(VpIsNaN(p))  return Qtrue;
    return Qfalse;
}

/* Returns True if the value is infinite */
static VALUE
BigDecimal_IsInfinite(VALUE self)
{
    Real *p = GetVpValue(self,1);
    if(VpIsPosInf(p)) return INT2FIX(1);
    if(VpIsNegInf(p)) return INT2FIX(-1);
    return Qnil;
}

/* Returns True if the value is finite (not NaN or infinite) */
static VALUE
BigDecimal_IsFinite(VALUE self)
{
    Real *p = GetVpValue(self,1);
    if(VpIsNaN(p)) return Qfalse;
    if(VpIsInf(p)) return Qfalse;
    return Qtrue;
}

static void
BigDecimal_check_num(Real *p)
{
    if(VpIsNaN(p)) {
       VpException(VP_EXCEPTION_NaN,"Computation results to 'NaN'(Not a Number)",1);
    } else if(VpIsPosInf(p)) {
       VpException(VP_EXCEPTION_INFINITY,"Computation results to 'Infinity'",1);
    } else if(VpIsNegInf(p)) {
       VpException(VP_EXCEPTION_INFINITY,"Computation results to '-Infinity'",1);
    }
}

/* Returns the value as an integer (Fixnum or Bignum).
 *
 * If the BigNumber is infinity or NaN, returns nil.
 */
static VALUE
BigDecimal_to_i(VALUE self)
{
    ENTER(5);
    int e,n,i,nf;
    U_LONG v,b,j;
    volatile VALUE str;
    char *psz,*pch;
    Real *p;

    GUARD_OBJ(p,GetVpValue(self,1));
    BigDecimal_check_num(p);

    e = VpExponent10(p);
    if(e<=0) return INT2FIX(0);
    nf = VpBaseFig();
    if(e<=nf) {
        e = VpGetSign(p)*p->frac[0];
        return INT2FIX(e);
    }
    str = rb_str_new(0, e+nf+2);
    psz = RSTRING_PTR(str);

    n = (e+nf-1)/nf;
    pch = psz;
    if(VpGetSign(p)<0) *pch++ = '-';
    for(i=0;i<n;++i) {
        b = VpBaseVal()/10;
        if(i>=(int)p->Prec) {
            while(b) {
                *pch++ = '0';
                b /= 10;
            }
            continue;
        }
        v = p->frac[i];
        while(b) {
            j = v/b;
            *pch++ = (char)(j + '0');
            v -= j*b;
            b /= 10;
        }
    }
    *pch++ = 0;
    return rb_cstr2inum(psz,10);
}

/* Returns a new Float object having approximately the same value as the
 * BigDecimal number. Normal accuracy limits and built-in errors of binary
 * Float arithmetic apply.
 */
static VALUE
BigDecimal_to_f(VALUE self)
{
    ENTER(1);
    Real *p;
    double d;
    S_LONG e;
    char *buf;
    volatile VALUE str;

    GUARD_OBJ(p,GetVpValue(self,1));
    if(VpVtoD(&d, &e, p)!=1) return rb_float_new(d);
    str = rb_str_new(0, VpNumOfChars(p,"E"));
    buf = RSTRING_PTR(str);
    VpToString(p, buf, 0, 0);
    errno = 0;
    d = strtod(buf, 0);
    if(errno == ERANGE) {
       VpException(VP_EXCEPTION_OVERFLOW,"BigDecimal to Float conversion",0);
       if(d>0.0) return rb_float_new(DBL_MAX);
       else      return rb_float_new(-DBL_MAX);
    }
    return rb_float_new(d);
}


static VALUE BigDecimal_split(VALUE self);

/* Converts a BigDecimal to a Rational.
 */
static VALUE
BigDecimal_to_r(VALUE self)
{
    Real *p;
    S_LONG sign, power, denomi_power;
    VALUE a, digits, numerator;

    p = GetVpValue(self,1);
    BigDecimal_check_num(p);

    sign = VpGetSign(p);
    power = VpExponent10(p);
    a = BigDecimal_split(self);
    digits = RARRAY_PTR(a)[1];
    denomi_power = power - RSTRING_LEN(digits);
    numerator = rb_funcall(digits, rb_intern("to_i"), 0);
    
    if (sign < 0) {
        numerator = rb_funcall(numerator, '*', 1, INT2FIX(-1));
    }
    if (denomi_power < 0) {
        return rb_Rational(numerator,
                           rb_funcall(INT2FIX(10), rb_intern("**"), 1,
                                      INT2FIX(-denomi_power)));
    }
    else {
        return rb_Rational1(rb_funcall(numerator, '*', 1,
                                       rb_funcall(INT2FIX(10), rb_intern("**"), 1,
                                                  INT2FIX(denomi_power))));
    }
}

/* The coerce method provides support for Ruby type coercion. It is not
 * enabled by default.
 * 
 * This means that binary operations like + * / or - can often be performed 
 * on a BigDecimal and an object of another type, if the other object can
 * be coerced into a BigDecimal value.
 *
 * e.g.
 * a = BigDecimal.new("1.0")
 * b = a / 2.0  -> 0.5
 *
 * Note that coercing a String to a BigDecimal is not supported by default;
 * it requires a special compile-time option when building Ruby.
 */
static VALUE
BigDecimal_coerce(VALUE self, VALUE other)
{
    ENTER(2);
    VALUE obj;
    Real *b;
    if(TYPE(other) == T_FLOAT) {
       obj = rb_assoc_new(other, BigDecimal_to_f(self));
    } else {
       GUARD_OBJ(b,GetVpValue(other,1));
       obj = rb_assoc_new(b->obj, self);
    }
    return obj;
}

static VALUE
BigDecimal_uplus(VALUE self)
{
    return self;
}

 /* call-seq:
  * add(value, digits)
  *
  * Add the specified value. 
  *
  * e.g.
  *   c = a.add(b,n)
  *   c = a + b
  *
  * digits:: If specified and less than the number of significant digits of the result, the result is rounded to that number of digits, according to BigDecimal.mode.
  */
static VALUE
BigDecimal_add(VALUE self, VALUE r)
{
    ENTER(5);
    Real *c, *a, *b;
    U_LONG mx;
    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) return DoSomeOne(self,r,'+');
    SAVE(b);
    if(VpIsNaN(b)) return b->obj;
    if(VpIsNaN(a)) return a->obj;
    mx = GetAddSubPrec(a,b);
    if(mx==(-1L)) {
        GUARD_OBJ(c,VpCreateRbObject(VpBaseFig() + 1, "0"));
        VpAddSub(c, a, b, 1);
    } else {
        GUARD_OBJ(c,VpCreateRbObject(mx *(VpBaseFig() + 1), "0"));
        if(!mx) {
            VpSetInf(c,VpGetSign(a));
        } else {
            VpAddSub(c, a, b, 1);
        }
    }
    return ToValue(c);
}

 /* call-seq:
  * sub(value, digits)
  *
  * Subtract the specified value. 
  *
  * e.g.
  *   c = a.sub(b,n)
  *   c = a - b
  *
  * digits:: If specified and less than the number of significant digits of the result, the result is rounded to that number of digits, according to BigDecimal.mode.
  */
static VALUE
BigDecimal_sub(VALUE self, VALUE r)
{
    ENTER(5);
    Real *c, *a, *b;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) return DoSomeOne(self,r,'-');
    SAVE(b);

    if(VpIsNaN(b)) return b->obj;
    if(VpIsNaN(a)) return a->obj;

    mx = GetAddSubPrec(a,b);
    if(mx==(-1L)) {
        GUARD_OBJ(c,VpCreateRbObject(VpBaseFig() + 1, "0"));
        VpAddSub(c, a, b, -1);
    } else {
        GUARD_OBJ(c,VpCreateRbObject(mx *(VpBaseFig() + 1), "0"));
        if(!mx) {
            VpSetInf(c,VpGetSign(a));
        } else {
            VpAddSub(c, a, b, -1);
        }
    }
    return ToValue(c);
}

static VALUE
BigDecimalCmp(VALUE self, VALUE r,char op)
{
    ENTER(5);
    S_INT e;
    Real *a, *b;
    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) {
        ID f = 0;

        switch(op)
        {
          case '*': f = rb_intern("<=>");break;
          case '=': f = rb_intern("=="); break;
          case '!': f = rb_intern("!="); break;
          case 'G': f = rb_intern(">="); break;
          case 'L': f = rb_intern("<="); break;
          case '>': case '<': f = (ID)op; break;
        }
        return rb_num_coerce_cmp(self,r,f);
    }
    SAVE(b);
    e = VpComp(a, b);
    if(e==999) return Qnil;
    switch(op)
    {
    case '*': return   INT2FIX(e); /* any op */
    case '=': if(e==0) return Qtrue ; return Qfalse;
    case '!': if(e!=0) return Qtrue ; return Qfalse;
    case 'G': if(e>=0) return Qtrue ; return Qfalse;
    case '>': if(e> 0) return Qtrue ; return Qfalse;
    case 'L': if(e<=0) return Qtrue ; return Qfalse;
    case '<': if(e< 0) return Qtrue ; return Qfalse;
    }
    rb_bug("Undefined operation in BigDecimalCmp()");
}

/* Returns True if the value is zero. */
static VALUE
BigDecimal_zero(VALUE self)
{
    Real *a = GetVpValue(self,1);
    return VpIsZero(a) ? Qtrue : Qfalse;
}

/* Returns True if the value is non-zero. */
static VALUE
BigDecimal_nonzero(VALUE self)
{
    Real *a = GetVpValue(self,1);
    return VpIsZero(a) ? Qnil : self;
}

/* The comparison operator.
 * a <=> b is 0 if a == b, 1 if a > b, -1 if a < b.
 */
static VALUE
BigDecimal_comp(VALUE self, VALUE r)
{
    return BigDecimalCmp(self, r, '*');
}

/*
 * Tests for value equality; returns true if the values are equal.
 *
 * The == and === operators and the eql? method have the same implementation 
 * for BigDecimal.
 *
 * Values may be coerced to perform the comparison:
 *
 * BigDecimal.new('1.0') == 1.0  -> true
 */
static VALUE
BigDecimal_eq(VALUE self, VALUE r)
{
    return BigDecimalCmp(self, r, '=');
}

/* call-seq:
 * a < b
 *
 * Returns true if a is less than b. Values may be coerced to perform the
 * comparison (see ==, coerce).
 */
static VALUE
BigDecimal_lt(VALUE self, VALUE r)
{
    return BigDecimalCmp(self, r, '<');
}

/* call-seq:
 * a <= b
 *
 * Returns true if a is less than or equal to b. Values may be coerced to 
 * perform the comparison (see ==, coerce).
 */
static VALUE
BigDecimal_le(VALUE self, VALUE r)
{
    return BigDecimalCmp(self, r, 'L');
}

/* call-seq:
 * a > b
 *
 * Returns true if a is greater than b.  Values may be coerced to 
 * perform the comparison (see ==, coerce).
 */
static VALUE
BigDecimal_gt(VALUE self, VALUE r)
{
    return BigDecimalCmp(self, r, '>');
}

/* call-seq:
 * a >= b
 *
 * Returns true if a is greater than or equal to b. Values may be coerced to 
 * perform the comparison (see ==, coerce)
 */
static VALUE
BigDecimal_ge(VALUE self, VALUE r)
{
    return BigDecimalCmp(self, r, 'G');
}

static VALUE
BigDecimal_neg(VALUE self)
{
    ENTER(5);
    Real *c, *a;
    GUARD_OBJ(a,GetVpValue(self,1));
    GUARD_OBJ(c,VpCreateRbObject(a->Prec *(VpBaseFig() + 1), "0"));
    VpAsgn(c, a, -1);
    return ToValue(c);
}

 /* call-seq:
  * mult(value, digits)
  *
  * Multiply by the specified value. 
  *
  * e.g.
  *   c = a.mult(b,n)
  *   c = a * b
  *
  * digits:: If specified and less than the number of significant digits of the result, the result is rounded to that number of digits, according to BigDecimal.mode.
  */
static VALUE
BigDecimal_mult(VALUE self, VALUE r)
{
    ENTER(5);
    Real *c, *a, *b;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) return DoSomeOne(self,r,'*');
    SAVE(b);

    mx = a->Prec + b->Prec;
    GUARD_OBJ(c,VpCreateRbObject(mx *(VpBaseFig() + 1), "0"));
    VpMult(c, a, b);
    return ToValue(c);
}

static VALUE
BigDecimal_divide(Real **c, Real **res, Real **div, VALUE self, VALUE r)
/* For c = self.div(r): with round operation */
{
    ENTER(5);
    Real *a, *b;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) return DoSomeOne(self,r,'/');
    SAVE(b);
    *div = b;
    mx =(a->MaxPrec + b->MaxPrec + 1) * VpBaseFig();
    GUARD_OBJ((*c),VpCreateRbObject(mx, "#0"));
    GUARD_OBJ((*res),VpCreateRbObject((mx+1) * 2 +(VpBaseFig() + 1), "#0"));
    VpDivd(*c, *res, a, b);
    return (VALUE)0;
}

 /* call-seq:
  * div(value, digits)
  * quo(value)
  *
  * Divide by the specified value. 
  *
  * e.g.
  *   c = a.div(b,n)
  *
  * digits:: If specified and less than the number of significant digits of the result, the result is rounded to that number of digits, according to BigDecimal.mode.
  * 
  * If digits is 0, the result is the same as the / operator. If not, the
  * result is an integer BigDecimal, by analogy with Float#div.
  *
  * The alias quo is provided since div(value, 0) is the same as computing
  * the quotient; see divmod.
  */
static VALUE
BigDecimal_div(VALUE self, VALUE r)
/* For c = self/r: with round operation */
{
    ENTER(5);
    Real *c=NULL, *res=NULL, *div = NULL;
    r = BigDecimal_divide(&c, &res, &div, self, r);
    if(r!=(VALUE)0) return r; /* coerced by other */
    SAVE(c);SAVE(res);SAVE(div);
    /* a/b = c + r/b */
    /* c xxxxx
       r 00000yyyyy  ==> (y/b)*BASE >= HALF_BASE
     */
    /* Round */
    if(VpHasVal(div)) { /* frac[0] must be zero for NaN,INF,Zero */
       VpInternalRound(c,0,c->frac[c->Prec-1],(VpBaseVal()*res->frac[0])/div->frac[0]);
    }
    return ToValue(c);
}

/*
 * %: mod = a%b = a - (a.to_f/b).floor * b
 * div = (a.to_f/b).floor
 */
static VALUE
BigDecimal_DoDivmod(VALUE self, VALUE r, Real **div, Real **mod)
{
    ENTER(8);
    Real *c=NULL, *d=NULL, *res=NULL;
    Real *a, *b;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) return DoSomeOne(self,r,rb_intern("divmod"));
    SAVE(b);

    if(VpIsNaN(a) || VpIsNaN(b)) goto NaN;
    if(VpIsInf(a) || VpIsInf(b)) goto NaN;
    if(VpIsZero(b))              goto NaN;
    if(VpIsZero(a)) {
       GUARD_OBJ(c,VpCreateRbObject(1, "0"));
       GUARD_OBJ(d,VpCreateRbObject(1, "0"));
       *div = d;
       *mod = c;
       return (VALUE)0;
    }

    mx = a->Prec;
    if(mx<b->Prec) mx = b->Prec;
    mx =(mx + 1) * VpBaseFig();
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    GUARD_OBJ(res,VpCreateRbObject((mx+1) * 2 +(VpBaseFig() + 1), "#0"));
    VpDivd(c, res, a, b);
    mx = c->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(d,VpCreateRbObject(mx, "0"));
    VpActiveRound(d,c,VP_ROUND_DOWN,0);
    VpMult(res,d,b);
    VpAddSub(c,a,res,-1);
    if(!VpIsZero(c) && (VpGetSign(a)*VpGetSign(b)<0)) {
        VpAddSub(res,d,VpOne(),-1);
        VpAddSub(d  ,c,b,       1);
        *div = res;
        *mod = d;
    } else {
        *div = d;
        *mod = c;
    }
    return (VALUE)0;

NaN:
    GUARD_OBJ(c,VpCreateRbObject(1, "NaN"));
    GUARD_OBJ(d,VpCreateRbObject(1, "NaN"));
    *div = d;
    *mod = c;
    return (VALUE)0;
}

/* call-seq:
 * a % b
 * a.modulo(b)
 *
 * Returns the modulus from dividing by b. See divmod.
 */
static VALUE
BigDecimal_mod(VALUE self, VALUE r) /* %: a%b = a - (a.to_f/b).floor * b */
{
    ENTER(3);
    VALUE obj;
    Real *div=NULL, *mod=NULL;

    obj = BigDecimal_DoDivmod(self,r,&div,&mod);
    if(obj!=(VALUE)0) return obj;
    SAVE(div);SAVE(mod);
    return ToValue(mod);
}

static VALUE
BigDecimal_divremain(VALUE self, VALUE r, Real **dv, Real **rv)
{
    ENTER(10);
    U_LONG mx;
    Real *a=NULL, *b=NULL, *c=NULL, *res=NULL, *d=NULL, *rr=NULL, *ff=NULL;
    Real *f=NULL;

    GUARD_OBJ(a,GetVpValue(self,1));
    b = GetVpValue(r,0);
    if(!b) return DoSomeOne(self,r,rb_intern("remainder"));
    SAVE(b);

    mx  =(a->MaxPrec + b->MaxPrec) *VpBaseFig();
    GUARD_OBJ(c  ,VpCreateRbObject(mx, "0"));
    GUARD_OBJ(res,VpCreateRbObject((mx+1) * 2 +(VpBaseFig() + 1), "#0"));
    GUARD_OBJ(rr ,VpCreateRbObject((mx+1) * 2 +(VpBaseFig() + 1), "#0"));
    GUARD_OBJ(ff ,VpCreateRbObject((mx+1) * 2 +(VpBaseFig() + 1), "#0"));

    VpDivd(c, res, a, b);

    mx = c->Prec *(VpBaseFig() + 1);

    GUARD_OBJ(d,VpCreateRbObject(mx, "0"));
    GUARD_OBJ(f,VpCreateRbObject(mx, "0"));

    VpActiveRound(d,c,VP_ROUND_DOWN,0); /* 0: round off */

    VpFrac(f, c);
    VpMult(rr,f,b);
    VpAddSub(ff,res,rr,1);

    *dv = d;
    *rv = ff;
    return (VALUE)0;
}

/* Returns the remainder from dividing by the value.
 *
 * If the values divided are of the same sign, the remainder is the same as
 * the modulus (see divmod).
 *
 * Otherwise, the remainder is the modulus minus the value divided by.
 */
static VALUE
BigDecimal_remainder(VALUE self, VALUE r) /* remainder */
{
    VALUE  f;
    Real  *d,*rv=0;
    f = BigDecimal_divremain(self,r,&d,&rv);
    if(f!=(VALUE)0) return f;
    return ToValue(rv);
}

/* Divides by the specified value, and returns the quotient and modulus
 * as BigDecimal numbers. The quotient is rounded towards negative infinity.
 *
 * For example:
 *
 * require 'bigdecimal'
 *
 * a = BigDecimal.new("42")
 * b = BigDecimal.new("9")
 *
 * q,m = a.divmod(b)
 *
 * c = q * b + m
 *
 * a == c  -> true
 *
 * The quotient q is (a/b).floor, and the modulus is the amount that must be 
 * added to q * b to get a.
 */
static VALUE
BigDecimal_divmod(VALUE self, VALUE r)
{
    ENTER(5);
    VALUE obj;
    Real *div=NULL, *mod=NULL;

    obj = BigDecimal_DoDivmod(self,r,&div,&mod);
    if(obj!=(VALUE)0) return obj;
    SAVE(div);SAVE(mod);
    obj = rb_assoc_new(ToValue(div), ToValue(mod));
    return obj;
}

static VALUE
BigDecimal_div2(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    VALUE b,n;
    int na = rb_scan_args(argc,argv,"11",&b,&n);
    if(na==1) { /* div in Float sense */
       VALUE obj;
       Real *div=NULL;
       Real *mod;
       obj = BigDecimal_DoDivmod(self,b,&div,&mod);
       if(obj!=(VALUE)0) return obj;
       if(VpIsNaN(div) && rb_equal(b, INT2FIX(0))) {
           rb_raise(rb_eZeroDivError, "divided by 0");
       }
       return BigDecimal_to_i(ToValue(div));
    } else {    /* div in BigDecimal sense */
       U_LONG ix = (U_LONG)GetPositiveInt(n);
       if(ix==0) return BigDecimal_div(self,b);
       else {
          Real *res=NULL;
          Real *av=NULL, *bv=NULL, *cv=NULL;
          U_LONG mx = (ix+VpBaseFig()*2);
          U_LONG pl = VpSetPrecLimit(0);

          GUARD_OBJ(cv,VpCreateRbObject(mx,"0"));
          GUARD_OBJ(av,GetVpValue(self,1));
          GUARD_OBJ(bv,GetVpValue(b,1));
          mx = av->Prec + bv->Prec + 2;
          if(mx <= cv->MaxPrec) mx = cv->MaxPrec+1;
          GUARD_OBJ(res,VpCreateRbObject((mx * 2  + 2)*VpBaseFig(), "#0"));
          VpDivd(cv,res,av,bv);
          VpSetPrecLimit(pl);
          VpLeftRound(cv,VpGetRoundMode(),ix);
          return ToValue(cv);
       }
    }
}

static VALUE
BigDecimal_add2(VALUE self, VALUE b, VALUE n)
{
    ENTER(2);
    Real   *cv;
    U_LONG mx = (U_LONG)GetPositiveInt(n);
    if(mx==0) return BigDecimal_add(self,b);
    else {
       U_LONG pl = VpSetPrecLimit(0);
       VALUE   c = BigDecimal_add(self,b);
       VpSetPrecLimit(pl);
       GUARD_OBJ(cv,GetVpValue(c,1));
       VpLeftRound(cv,VpGetRoundMode(),mx);
       return ToValue(cv);
    }
}

static VALUE
BigDecimal_sub2(VALUE self, VALUE b, VALUE n)
{
    ENTER(2);
    Real *cv;
    U_LONG mx = (U_LONG)GetPositiveInt(n);
    if(mx==0) return BigDecimal_sub(self,b);
    else {
       U_LONG pl = VpSetPrecLimit(0);
       VALUE   c = BigDecimal_sub(self,b);
       VpSetPrecLimit(pl);
       GUARD_OBJ(cv,GetVpValue(c,1));
       VpLeftRound(cv,VpGetRoundMode(),mx);
       return ToValue(cv);
    }
}

static VALUE
BigDecimal_mult2(VALUE self, VALUE b, VALUE n)
{
    ENTER(2);
    Real *cv;
    U_LONG mx = (U_LONG)GetPositiveInt(n);
    if(mx==0) return BigDecimal_mult(self,b);
    else {
       U_LONG pl = VpSetPrecLimit(0);
       VALUE   c = BigDecimal_mult(self,b);
       VpSetPrecLimit(pl);
       GUARD_OBJ(cv,GetVpValue(c,1));
       VpLeftRound(cv,VpGetRoundMode(),mx);
       return ToValue(cv);
    }
}

/* Returns the absolute value.
 *
 * BigDecimal('5').abs -> 5
 *
 * BigDecimal('-3').abs -> 3
 */
static VALUE
BigDecimal_abs(VALUE self)
{
    ENTER(5);
    Real *c, *a;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpAsgn(c, a, 1);
    VpChangeSign(c,(S_INT)1);
    return ToValue(c);
}

/* call-seq:
 * sqrt(n)
 *
 * Returns the square root of the value.
 *
 * If n is specified, returns at least that many significant digits.
 */
static VALUE
BigDecimal_sqrt(VALUE self, VALUE nFig)
{
    ENTER(5);
    Real *c, *a;
    S_INT mx, n;

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);

    n = GetPositiveInt(nFig) + VpDblFig() + 1;
    if(mx <= n) mx = n;
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpSqrt(c, a);
    return ToValue(c);
}

/* Return the integer part of the number.
 */
static VALUE
BigDecimal_fix(VALUE self)
{
    ENTER(5);
    Real *c, *a;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpActiveRound(c,a,VP_ROUND_DOWN,0); /* 0: round off */
    return ToValue(c);
}

/* call-seq:
 * round(n,mode)
 *
 * Round to the nearest 1 (by default), returning the result as a BigDecimal.
 *
 * BigDecimal('3.14159').round -> 3
 *
 * BigDecimal('8.7').round -> 9
 *
 * If n is specified and positive, the fractional part of the result has no
 * more than that many digits. 
 *
 * If n is specified and negative, at least that many digits to the left of the
 * decimal point will be 0 in the result.
 *
 * BigDecimal('3.14159').round(3) -> 3.142
 *
 * BigDecimal('13345.234').round(-2) -> 13300.0
 *
 * The value of the optional mode argument can be used to determine how 
 * rounding is performed; see BigDecimal.mode.
 */
static VALUE
BigDecimal_round(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real   *c, *a;
    int    iLoc = 0;
    U_LONG mx;
    VALUE  vLoc;
    VALUE  vRound;
    U_LONG pl;

    int    sw = VpGetRoundMode();

    int na = rb_scan_args(argc,argv,"02",&vLoc,&vRound);
    switch(na) {
    case 0:
        iLoc = 0;
        break;
    case 1:
        Check_Type(vLoc, T_FIXNUM);
        iLoc = FIX2INT(vLoc);
        break;
    case 2:
        Check_Type(vLoc, T_FIXNUM);
        iLoc = FIX2INT(vLoc);
        Check_Type(vRound, T_FIXNUM);
        sw   = FIX2INT(vRound);
        if(!VpIsRoundMode(sw)) {
            rb_raise(rb_eTypeError, "invalid rounding mode");
            return Qnil;
        }
        break;
    }

    pl = VpSetPrecLimit(0);
    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpSetPrecLimit(pl);
    VpActiveRound(c,a,sw,iLoc);
    return ToValue(c);
}

/* call-seq:
 * truncate(n)
 *
 * Truncate to the nearest 1, returning the result as a BigDecimal.
 *
 * BigDecimal('3.14159').truncate -> 3
 *
 * BigDecimal('8.7').truncate -> 8
 *
 * If n is specified and positive, the fractional part of the result has no
 * more than that many digits. 
 *
 * If n is specified and negative, at least that many digits to the left of the
 * decimal point will be 0 in the result.
 *
 * BigDecimal('3.14159').truncate(3) -> 3.141
 *
 * BigDecimal('13345.234').truncate(-2) -> 13300.0
 */
static VALUE
BigDecimal_truncate(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *c, *a;
    int iLoc;
    U_LONG mx;
    VALUE vLoc;
    U_LONG pl = VpSetPrecLimit(0);

    if(rb_scan_args(argc,argv,"01",&vLoc)==0) {
        iLoc = 0;
    } else {
        Check_Type(vLoc, T_FIXNUM);
        iLoc = FIX2INT(vLoc);
    }

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpSetPrecLimit(pl);
    VpActiveRound(c,a,VP_ROUND_DOWN,iLoc); /* 0: truncate */
    return ToValue(c);
}

/* Return the fractional part of the number.
 */
static VALUE
BigDecimal_frac(VALUE self)
{
    ENTER(5);
    Real *c, *a;
    U_LONG mx;

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpFrac(c, a);
    return ToValue(c);
}

/* call-seq:
 * floor(n)
 *
 * Return the largest integer less than or equal to the value, as a BigDecimal.
 *
 * BigDecimal('3.14159').floor -> 3
 *
 * BigDecimal('-9.1').floor -> -10
 *
 * If n is specified and positive, the fractional part of the result has no
 * more than that many digits.  
 *
 * If n is specified and negative, at least that
 * many digits to the left of the decimal point will be 0 in the result.
 *
 * BigDecimal('3.14159').floor(3) -> 3.141
 *
 * BigDecimal('13345.234').floor(-2) -> 13300.0
 */
static VALUE
BigDecimal_floor(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *c, *a;
    U_LONG mx;
    int iLoc;
    VALUE vLoc;
    U_LONG pl = VpSetPrecLimit(0);

    if(rb_scan_args(argc,argv,"01",&vLoc)==0) {
        iLoc = 0;
    } else {
        Check_Type(vLoc, T_FIXNUM);
        iLoc = FIX2INT(vLoc);
    }

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpSetPrecLimit(pl);
    VpActiveRound(c,a,VP_ROUND_FLOOR,iLoc);
    return ToValue(c);
}

/* call-seq:
 * ceil(n)
 *
 * Return the smallest integer greater than or equal to the value, as a BigDecimal.
 *
 * BigDecimal('3.14159').ceil -> 4
 *
 * BigDecimal('-9.1').ceil -> -9
 *
 * If n is specified and positive, the fractional part of the result has no
 * more than that many digits.  
 *
 * If n is specified and negative, at least that
 * many digits to the left of the decimal point will be 0 in the result.
 *
 * BigDecimal('3.14159').ceil(3) -> 3.142
 *
 * BigDecimal('13345.234').ceil(-2) -> 13400.0
 */
static VALUE
BigDecimal_ceil(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *c, *a;
    U_LONG mx;
    int iLoc;
    VALUE vLoc;
    U_LONG pl = VpSetPrecLimit(0);

    if(rb_scan_args(argc,argv,"01",&vLoc)==0) {
        iLoc = 0;
    } else {
        Check_Type(vLoc, T_FIXNUM);
        iLoc = FIX2INT(vLoc);
    }

    GUARD_OBJ(a,GetVpValue(self,1));
    mx = a->Prec *(VpBaseFig() + 1);
    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
    VpSetPrecLimit(pl);
    VpActiveRound(c,a,VP_ROUND_CEIL,iLoc);
    return ToValue(c);
}

/* call-seq:
 * to_s(s)
 *
 * Converts the value to a string.
 *
 * The default format looks like  0.xxxxEnn.
 *
 * The optional parameter s consists of either an integer; or an optional '+'
 * or ' ', followed by an optional number, followed by an optional 'E' or 'F'.
 *
 * If there is a '+' at the start of s, positive values are returned with
 * a leading '+'.
 *
 * A space at the start of s returns positive values with a leading space.
 *
 * If s contains a number, a space is inserted after each group of that many 
 * fractional digits.
 *
 * If s ends with an 'E', engineering notation (0.xxxxEnn) is used.
 *
 * If s ends with an 'F', conventional floating point notation is used.
 *
 * Examples:
 *
 * BigDecimal.new('-123.45678901234567890').to_s('5F') -> '-123.45678 90123 45678 9'
 *
 * BigDecimal.new('123.45678901234567890').to_s('+8F') -> '+123.45678901 23456789'
 *
 * BigDecimal.new('123.45678901234567890').to_s(' F') -> ' 123.4567890123456789'
 */
static VALUE
BigDecimal_to_s(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    int   fmt=0;   /* 0:E format */
    int   fPlus=0; /* =0:default,=1: set ' ' before digits ,set '+' before digits. */
    Real  *vp;
    volatile VALUE str;
    char  *psz;
    char   ch;
    U_LONG nc;
    S_INT  mc = 0;
    VALUE  f;

    GUARD_OBJ(vp,GetVpValue(self,1));
    
    if(rb_scan_args(argc,argv,"01",&f)==1) {
        if(TYPE(f)==T_STRING) {
            SafeStringValue(f);
            psz = RSTRING_PTR(f);
            if(*psz==' ') {
                fPlus = 1; psz++;
            } else if(*psz=='+') {
                fPlus = 2; psz++;
            }
            while((ch=*psz++)!=0) {
                if(ISSPACE(ch)) continue;
                if(!ISDIGIT(ch)) {
                    if(ch=='F' || ch=='f') fmt = 1; /* F format */
                    break;
                }
                mc = mc * 10 + ch - '0';
            }
        } else {
            mc  = GetPositiveInt(f);
        }
    }
    if(fmt) {
        nc = VpNumOfChars(vp,"F");
    } else {
        nc = VpNumOfChars(vp,"E");
    }
    if(mc>0) nc += (nc + mc - 1) / mc + 1;

    str = rb_str_new(0, nc);
    psz = RSTRING_PTR(str);

    if(fmt) {
        VpToFString(vp, psz, mc, fPlus);
    } else {
        VpToString (vp, psz, mc, fPlus);
    }
    rb_str_resize(str, strlen(psz));
    return str;
}

/* Splits a BigDecimal number into four parts, returned as an array of values.
 *
 * The first value represents the sign of the BigDecimal, and is -1 or 1, or 0
 * if the BigDecimal is Not a Number.
 *
 * The second value is a string representing the significant digits of the
 * BigDecimal, with no leading zeros.
 *
 * The third value is the base used for arithmetic (currently always 10) as an
 * Integer.
 *
 * The fourth value is an Integer exponent.
 *
 * If the BigDecimal can be represented as 0.xxxxxx*10**n, then xxxxxx is the 
 * string of significant digits with no leading zeros, and n is the exponent.
 *
 * From these values, you can translate a BigDecimal to a float as follows:
 *
 *   sign, significant_digits, base, exponent = a.split
 *   f = sign * "0.#{significant_digits}".to_f * (base ** exponent)
 *
 * (Note that the to_f method is provided as a more convenient way to translate 
 * a BigDecimal to a Float.)
 */
static VALUE
BigDecimal_split(VALUE self)
{
    ENTER(5);
    Real *vp;
    VALUE obj,str;
    S_LONG e;
    S_LONG s;
    char *psz1;

    GUARD_OBJ(vp,GetVpValue(self,1));
    str = rb_str_new(0, VpNumOfChars(vp,"E"));
    psz1 = RSTRING_PTR(str);
    VpSzMantissa(vp,psz1);
    s = 1;
    if(psz1[0]=='-') {
        int len = strlen(psz1+1);

        memmove(psz1, psz1+1, len);
        psz1[len] = '\0';
        s = -1;
    }
    if(psz1[0]=='N') s=0; /* NaN */
    e = VpExponent10(vp);
    obj  = rb_ary_new2(4);
    rb_ary_push(obj, INT2FIX(s));
    rb_ary_push(obj, str);
    rb_str_resize(str, strlen(psz1));
    rb_ary_push(obj, INT2FIX(10));
    rb_ary_push(obj, INT2NUM(e));
    return obj;
}

/* Returns the exponent of the BigDecimal number, as an Integer.
 *
 * If the number can be represented as 0.xxxxxx*10**n where xxxxxx is a string
 * of digits with no leading zeros, then n is the exponent.
 */
static VALUE
BigDecimal_exponent(VALUE self)
{
    S_LONG e = VpExponent10(GetVpValue(self,1));
    return INT2NUM(e);
}

/* Returns debugging information about the value as a string of comma-separated
 * values in angle brackets with a leading #:
 *
 * BigDecimal.new("1234.5678").inspect ->
 * "#<BigDecimal:b7ea1130,'0.12345678E4',8(12)>"
 *
 * The first part is the address, the second is the value as a string, and
 * the final part ss(mm) is the current number of significant digits and the
 * maximum number of significant digits, respectively.
 */
static VALUE
BigDecimal_inspect(VALUE self)
{
    ENTER(5);
    Real *vp;
    volatile VALUE obj;
    unsigned int nc;
    char *psz, *tmp;

    GUARD_OBJ(vp,GetVpValue(self,1));
    nc = VpNumOfChars(vp,"E");
    nc +=(nc + 9) / 10;

    obj = rb_str_new(0, nc+256);
    psz = RSTRING_PTR(obj);
    sprintf(psz,"#<BigDecimal:%lx,'",self);
    tmp = psz + strlen(psz);
    VpToString(vp, tmp, 10, 0);
    tmp += strlen(tmp);
    sprintf(tmp,"',%lu(%lu)>",VpPrec(vp)*VpBaseFig(),VpMaxPrec(vp)*VpBaseFig());
    rb_str_resize(obj, strlen(psz));
    return obj;
}

/* call-seq:
 * power(n)
 *
 * Returns the value raised to the power of n. Note that n must be an Integer.
 *
 * Also available as the operator **
 */
static VALUE
BigDecimal_power(VALUE self, VALUE p)
{
    ENTER(5);
    Real *x, *y;
    S_LONG mp, ma, n;

    Check_Type(p, T_FIXNUM);
    n = FIX2INT(p);
    ma = n;
    if(ma < 0)  ma = -ma;
    if(ma == 0) ma = 1;

    GUARD_OBJ(x,GetVpValue(self,1));
    if(VpIsDef(x)) {
        mp = x->Prec *(VpBaseFig() + 1);
        GUARD_OBJ(y,VpCreateRbObject(mp *(ma + 1), "0"));
    } else {
        GUARD_OBJ(y,VpCreateRbObject(1, "0"));
    }
    VpPower(y, x, n);
    return ToValue(y);
}

static VALUE
BigDecimal_global_new(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *pv;
    S_LONG mf;
    VALUE  nFig;
    VALUE  iniValue;

    if(rb_scan_args(argc,argv,"11",&iniValue,&nFig)==1) {
        mf = 0;
    } else {
        mf = GetPositiveInt(nFig);
    }
    SafeStringValue(iniValue);
    GUARD_OBJ(pv,VpCreateRbObject(mf, RSTRING_PTR(iniValue)));
    return ToValue(pv);
}

 /* call-seq:
  * new(initial, digits)
  *
  * Create a new BigDecimal object.
  *
  * initial:: The initial value, as a String. Spaces are ignored, unrecognized characters terminate the value.
  *
  * digits:: The number of significant digits, as a Fixnum. If omitted or 0, the number of significant digits is determined from the initial value.
  *
  * The actual number of significant digits used in computation is usually
  * larger than the specified number.
  */
static VALUE
BigDecimal_new(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *pv;
    S_LONG mf;
    VALUE  nFig;
    VALUE  iniValue;

    if(rb_scan_args(argc,argv,"11",&iniValue,&nFig)==1) {
        mf = 0;
    } else {
        mf = GetPositiveInt(nFig);
    }
    SafeStringValue(iniValue);
    GUARD_OBJ(pv,VpNewRbClass(mf, RSTRING_PTR(iniValue),self));
    return ToValue(pv);
}

 /* call-seq:
  * BigDecimal.limit(digits)
  *
  * Limit the number of significant digits in newly created BigDecimal 
  * numbers to the specified value. Rounding is performed as necessary, 
  * as specified by BigDecimal.mode.
  *
  * A limit of 0, the default, means no upper limit.
  *
  * The limit specified by this method takes less priority over any limit 
  * specified to instance methods such as ceil, floor, truncate, or round.
  */
static VALUE
BigDecimal_limit(int argc, VALUE *argv, VALUE self)
{
    VALUE  nFig;
    VALUE  nCur = INT2NUM(VpGetPrecLimit());

    if(rb_scan_args(argc,argv,"01",&nFig)==1) {
        int nf;
        if(nFig==Qnil) return nCur;
        Check_Type(nFig, T_FIXNUM);
        nf = FIX2INT(nFig);
        if(nf<0) {
            rb_raise(rb_eArgError, "argument must be positive");
        }
        VpSetPrecLimit(nf);
    }
    return nCur;
}

/* Returns the sign of the value.
 *
 * Returns a positive value if > 0, a negative value if < 0, and a 
 * zero if == 0.
 *
 * The specific value returned indicates the type and sign of the BigDecimal, 
 * as follows:
 *
 * BigDecimal::SIGN_NaN:: value is Not a Number
 * BigDecimal::SIGN_POSITIVE_ZERO:: value is +0
 * BigDecimal::SIGN_NEGATIVE_ZERO:: value is -0
 * BigDecimal::SIGN_POSITIVE_INFINITE:: value is +infinity
 * BigDecimal::SIGN_NEGATIVE_INFINITE:: value is -infinity
 * BigDecimal::SIGN_POSITIVE_FINITE:: value is positive
 * BigDecimal::SIGN_NEGATIVE_FINITE:: value is negative
 */
static VALUE
BigDecimal_sign(VALUE self)
{ /* sign */
    int s = GetVpValue(self,1)->sign;
    return INT2FIX(s);
}

void
Init_bigdecimal(void)
{
    /* Initialize VP routines */
    VpInit((U_LONG)0);

    /* Class and method registration */
    rb_cBigDecimal = rb_define_class("BigDecimal",rb_cNumeric);

    /* Global function */
    rb_define_global_function("BigDecimal", BigDecimal_global_new, -1);

    /* Class methods */
    rb_define_singleton_method(rb_cBigDecimal, "new", BigDecimal_new, -1);
    rb_define_singleton_method(rb_cBigDecimal, "mode", BigDecimal_mode, -1);
    rb_define_singleton_method(rb_cBigDecimal, "limit", BigDecimal_limit, -1);
    rb_define_singleton_method(rb_cBigDecimal, "double_fig", BigDecimal_double_fig, 0);
    rb_define_singleton_method(rb_cBigDecimal, "_load", BigDecimal_load, 1);
    rb_define_singleton_method(rb_cBigDecimal, "ver", BigDecimal_version, 0);

    /* Constants definition */

    /* 
     * Base value used in internal calculations.  On a 32 bit system, BASE 
     * is 10000, indicating that calculation is done in groups of 4 digits.  
     * (If it were larger, BASE**2 wouldn't fit in 32 bits, so you couldn't
     * guarantee that two groups could always be multiplied together without 
     * overflow.) 
     */
    rb_define_const(rb_cBigDecimal, "BASE", INT2FIX((S_INT)VpBaseVal()));

    /* Exceptions */

    /*
     * 0xff: Determines whether overflow, underflow or zero divide result in 
     * an exception being thrown. See BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "EXCEPTION_ALL",INT2FIX(VP_EXCEPTION_ALL));

    /* 
     * 0x02: Determines what happens when the result of a computation is not a 
     * number (NaN). See BigDecimal.mode. 
     */
    rb_define_const(rb_cBigDecimal, "EXCEPTION_NaN",INT2FIX(VP_EXCEPTION_NaN));

    /* 
     * 0x01: Determines what happens when the result of a computation is
     * infinity.  See BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "EXCEPTION_INFINITY",INT2FIX(VP_EXCEPTION_INFINITY));

    /* 
     * 0x04: Determines what happens when the result of a computation is an
     * underflow (a result too small to be represented). See BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "EXCEPTION_UNDERFLOW",INT2FIX(VP_EXCEPTION_UNDERFLOW));

    /* 
     * 0x01: Determines what happens when the result of a computation is an
     * overflow (a result too large to be represented). See BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "EXCEPTION_OVERFLOW",INT2FIX(VP_EXCEPTION_OVERFLOW));

    /* 
     * 0x01: Determines what happens when a division by zero is performed.
     * See BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "EXCEPTION_ZERODIVIDE",INT2FIX(VP_EXCEPTION_ZERODIVIDE));

    /* 
     * 0x100: Determines what happens when a result must be rounded in order to
     * fit in the appropriate number of significant digits. See
     * BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "ROUND_MODE",INT2FIX(VP_ROUND_MODE));

    /* 1: Indicates that values should be rounded away from zero. See
     * BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "ROUND_UP",INT2FIX(VP_ROUND_UP));

    /* 2: Indicates that values should be rounded towards zero. See
     * BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "ROUND_DOWN",INT2FIX(VP_ROUND_DOWN));

    /* 3: Indicates that digits >= 5 should be rounded up, others rounded down.
     * See BigDecimal.mode. */
    rb_define_const(rb_cBigDecimal, "ROUND_HALF_UP",INT2FIX(VP_ROUND_HALF_UP));

    /* 4: Indicates that digits >= 6 should be rounded up, others rounded down.
     * See BigDecimal.mode.
     */
    rb_define_const(rb_cBigDecimal, "ROUND_HALF_DOWN",INT2FIX(VP_ROUND_HALF_DOWN));
    /* 5: Round towards +infinity. See BigDecimal.mode. */
    rb_define_const(rb_cBigDecimal, "ROUND_CEILING",INT2FIX(VP_ROUND_CEIL));

    /* 6: Round towards -infinity. See BigDecimal.mode. */
    rb_define_const(rb_cBigDecimal, "ROUND_FLOOR",INT2FIX(VP_ROUND_FLOOR));

    /* 7: Round towards the even neighbor. See BigDecimal.mode. */
    rb_define_const(rb_cBigDecimal, "ROUND_HALF_EVEN",INT2FIX(VP_ROUND_HALF_EVEN));

    /* 0: Indicates that a value is not a number. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_NaN",INT2FIX(VP_SIGN_NaN));

    /* 1: Indicates that a value is +0. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_POSITIVE_ZERO",INT2FIX(VP_SIGN_POSITIVE_ZERO));

    /* -1: Indicates that a value is -0. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_NEGATIVE_ZERO",INT2FIX(VP_SIGN_NEGATIVE_ZERO));

    /* 2: Indicates that a value is positive and finite. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_POSITIVE_FINITE",INT2FIX(VP_SIGN_POSITIVE_FINITE));

    /* -2: Indicates that a value is negative and finite. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_NEGATIVE_FINITE",INT2FIX(VP_SIGN_NEGATIVE_FINITE));

    /* 3: Indicates that a value is positive and infinite. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_POSITIVE_INFINITE",INT2FIX(VP_SIGN_POSITIVE_INFINITE));

    /* -3: Indicates that a value is negative and infinite. See BigDecimal.sign. */
    rb_define_const(rb_cBigDecimal, "SIGN_NEGATIVE_INFINITE",INT2FIX(VP_SIGN_NEGATIVE_INFINITE));

    /* instance methods */
    rb_define_method(rb_cBigDecimal, "precs", BigDecimal_prec, 0);

    rb_define_method(rb_cBigDecimal, "add", BigDecimal_add2, 2);
    rb_define_method(rb_cBigDecimal, "sub", BigDecimal_sub2, 2);
    rb_define_method(rb_cBigDecimal, "mult", BigDecimal_mult2, 2);
    rb_define_method(rb_cBigDecimal, "div",BigDecimal_div2, -1);
    rb_define_method(rb_cBigDecimal, "hash", BigDecimal_hash, 0);
    rb_define_method(rb_cBigDecimal, "to_s", BigDecimal_to_s, -1);
    rb_define_method(rb_cBigDecimal, "to_i", BigDecimal_to_i, 0);
    rb_define_method(rb_cBigDecimal, "to_int", BigDecimal_to_i, 0);
    rb_define_method(rb_cBigDecimal, "to_r", BigDecimal_to_r, 0);
    rb_define_method(rb_cBigDecimal, "split", BigDecimal_split, 0);
    rb_define_method(rb_cBigDecimal, "+", BigDecimal_add, 1);
    rb_define_method(rb_cBigDecimal, "-", BigDecimal_sub, 1);
    rb_define_method(rb_cBigDecimal, "+@", BigDecimal_uplus, 0);
    rb_define_method(rb_cBigDecimal, "-@", BigDecimal_neg, 0);
    rb_define_method(rb_cBigDecimal, "*", BigDecimal_mult, 1);
    rb_define_method(rb_cBigDecimal, "/", BigDecimal_div, 1);
    rb_define_method(rb_cBigDecimal, "quo", BigDecimal_div, 1);
    rb_define_method(rb_cBigDecimal, "%", BigDecimal_mod, 1);
    rb_define_method(rb_cBigDecimal, "modulo", BigDecimal_mod, 1);
    rb_define_method(rb_cBigDecimal, "remainder", BigDecimal_remainder, 1);
    rb_define_method(rb_cBigDecimal, "divmod", BigDecimal_divmod, 1);
    /* rb_define_method(rb_cBigDecimal, "dup", BigDecimal_dup, 0); */
    rb_define_method(rb_cBigDecimal, "to_f", BigDecimal_to_f, 0);
    rb_define_method(rb_cBigDecimal, "abs", BigDecimal_abs, 0);
    rb_define_method(rb_cBigDecimal, "sqrt", BigDecimal_sqrt, 1);
    rb_define_method(rb_cBigDecimal, "fix", BigDecimal_fix, 0);
    rb_define_method(rb_cBigDecimal, "round", BigDecimal_round, -1);
    rb_define_method(rb_cBigDecimal, "frac", BigDecimal_frac, 0);
    rb_define_method(rb_cBigDecimal, "floor", BigDecimal_floor, -1);
    rb_define_method(rb_cBigDecimal, "ceil", BigDecimal_ceil, -1);
    rb_define_method(rb_cBigDecimal, "power", BigDecimal_power, 1);
    rb_define_method(rb_cBigDecimal, "**", BigDecimal_power, 1);
    rb_define_method(rb_cBigDecimal, "<=>", BigDecimal_comp, 1);
    rb_define_method(rb_cBigDecimal, "==", BigDecimal_eq, 1);
    rb_define_method(rb_cBigDecimal, "===", BigDecimal_eq, 1);
    rb_define_method(rb_cBigDecimal, "eql?", BigDecimal_eq, 1);
    rb_define_method(rb_cBigDecimal, "<", BigDecimal_lt, 1);
    rb_define_method(rb_cBigDecimal, "<=", BigDecimal_le, 1);
    rb_define_method(rb_cBigDecimal, ">", BigDecimal_gt, 1);
    rb_define_method(rb_cBigDecimal, ">=", BigDecimal_ge, 1);
    rb_define_method(rb_cBigDecimal, "zero?", BigDecimal_zero, 0);
    rb_define_method(rb_cBigDecimal, "nonzero?", BigDecimal_nonzero, 0);
    rb_define_method(rb_cBigDecimal, "coerce", BigDecimal_coerce, 1);
    rb_define_method(rb_cBigDecimal, "inspect", BigDecimal_inspect, 0);
    rb_define_method(rb_cBigDecimal, "exponent", BigDecimal_exponent, 0);
    rb_define_method(rb_cBigDecimal, "sign", BigDecimal_sign, 0);
    rb_define_method(rb_cBigDecimal, "nan?",      BigDecimal_IsNaN, 0);
    rb_define_method(rb_cBigDecimal, "infinite?", BigDecimal_IsInfinite, 0);
    rb_define_method(rb_cBigDecimal, "finite?",   BigDecimal_IsFinite, 0);
    rb_define_method(rb_cBigDecimal, "truncate",  BigDecimal_truncate, -1);
    rb_define_method(rb_cBigDecimal, "_dump", BigDecimal_dump, -1);
}

/*
 *
 *  ============================================================================
 *
 *  vp_ routines begin from here.
 *
 *  ============================================================================
 *
 */
#ifdef _DEBUG
/*static int gfDebug = 1;*/         /* Debug switch */
static int gfCheckVal = 1;      /* Value checking flag in VpNmlz()  */
#endif /* _DEBUG */

static U_LONG gnPrecLimit = 0;  /* Global upper limit of the precision newly allocated */
static U_LONG gfRoundMode = VP_ROUND_HALF_UP; /* Mode for general rounding operation   */

#ifndef BASE_FIG
static U_LONG BASE_FIG = 4;     /* =log10(BASE)  */
static U_LONG BASE = 10000L;    /* Base value(value must be 10**BASE_FIG) */
                /* The value of BASE**2 + BASE must be represented */
                /* within one U_LONG. */
static U_LONG HALF_BASE = 5000L;/* =BASE/2  */
static U_LONG BASE1 = 1000L;    /* =BASE/10  */
#else
#ifndef BASE
#error BASE_FIG is defined but BASE is not
#endif
#define HALF_BASE (BASE/2)
#define BASE1 (BASE/10)
#endif
#ifndef DBLE_FIG
#define DBLE_FIG (DBL_DIG+1)    /* figure of double */
#endif

static Real *VpConstOne;    /* constant 1.0 */
static Real *VpPt5;        /* constant 0.5 */
#define maxnr 100UL    /* Maximum iterations for calcurating sqrt. */
                /* used in VpSqrt() */

/* ETC */
#define MemCmp(x,y,z) memcmp(x,y,z)
#define StrCmp(x,y)   strcmp(x,y)

static int VpIsDefOP(Real *c,Real *a,Real *b,int sw);
static int AddExponent(Real *a,S_INT n);
static U_LONG VpAddAbs(Real *a,Real *b,Real *c);
static U_LONG VpSubAbs(Real *a,Real *b,Real *c);
static U_LONG VpSetPTR(Real *a,Real *b,Real *c,U_LONG *a_pos,U_LONG *b_pos,U_LONG *c_pos,U_LONG *av,U_LONG *bv);
static int VpNmlz(Real *a);
static void VpFormatSt(char *psz,S_INT fFmt);
static int VpRdup(Real *m,U_LONG ind_m);

#ifdef _DEBUG
static int gnAlloc=0; /* Memory allocation counter */
#endif /* _DEBUG */

VP_EXPORT void *
VpMemAlloc(U_LONG mb)
{
    void *p = xmalloc((unsigned int)mb);
    if(!p) {
        VpException(VP_EXCEPTION_MEMORY,"failed to allocate memory",1);
    }
    memset(p,0,mb);
#ifdef _DEBUG
    gnAlloc++; /* Count allocation call */
#endif /* _DEBUG */
    return p;
}

VP_EXPORT void
VpFree(Real *pv)
{
    if(pv != NULL) {
        xfree(pv);
#ifdef _DEBUG
        gnAlloc--; /* Decrement allocation count */
        if(gnAlloc==0) {
            printf(" *************** All memories allocated freed ****************");
            getchar();
        }
        if(gnAlloc<0) {
            printf(" ??????????? Too many memory free calls(%d) ?????????????\n",gnAlloc);
            getchar();
        }
#endif /* _DEBUG */
    }
}

/*
 * EXCEPTION Handling.
 */
static unsigned short gfDoException = 0; /* Exception flag */

static unsigned short
VpGetException (void)
{
    return gfDoException;
}

static void
VpSetException(unsigned short f)
{
    gfDoException = f;
}

/* These 2 functions added at v1.1.7 */
VP_EXPORT U_LONG
VpGetPrecLimit(void)
{
    return gnPrecLimit;
}

VP_EXPORT U_LONG
VpSetPrecLimit(U_LONG n)
{
    U_LONG s = gnPrecLimit;
    gnPrecLimit = n;
    return s;
}

VP_EXPORT unsigned long
VpGetRoundMode(void)
{
    return gfRoundMode;
}

VP_EXPORT int
VpIsRoundMode(unsigned long n)
{
    if(n==VP_ROUND_UP      || n==VP_ROUND_DOWN      ||
       n==VP_ROUND_HALF_UP || n==VP_ROUND_HALF_DOWN ||
       n==VP_ROUND_CEIL    || n==VP_ROUND_FLOOR     ||
       n==VP_ROUND_HALF_EVEN
      ) return 1;
    return 0;
}

VP_EXPORT unsigned long
VpSetRoundMode(unsigned long n)
{
    if(VpIsRoundMode(n)) gfRoundMode = n;
    return gfRoundMode;
}

/*
 *  0.0 & 1.0 generator
 *    These gZero_..... and gOne_..... can be any name
 *    referenced from nowhere except Zero() and One().
 *    gZero_..... and gOne_..... must have global scope
 *    (to let the compiler know they may be changed in outside
 *    (... but not actually..)).
 */
volatile const double gZero_ABCED9B1_CE73__00400511F31D = 0.0;
volatile const double gOne_ABCED9B4_CE73__00400511F31D  = 1.0;
static double
Zero(void)
{
    return gZero_ABCED9B1_CE73__00400511F31D;
}

static double
One(void)
{
    return gOne_ABCED9B4_CE73__00400511F31D;
}

VP_EXPORT U_LONG
VpBaseFig(void)
{
    return BASE_FIG;
}

VP_EXPORT U_LONG
VpDblFig(void)
{
    return DBLE_FIG;
}

VP_EXPORT U_LONG
VpBaseVal(void)
{
    return BASE;
}

/*
  ----------------------------------------------------------------
  Value of sign in Real structure is reserved for future use.
  short sign;
                    ==0 : NaN
                      1 : Positive zero
                     -1 : Negative zero
                      2 : Positive number
                     -2 : Negative number
                      3 : Positive infinite number
                     -3 : Negative infinite number
  ----------------------------------------------------------------
*/

VP_EXPORT double
VpGetDoubleNaN(void) /* Returns the value of NaN */
{
    static double fNaN = 0.0;
    if(fNaN==0.0) fNaN = Zero()/Zero();
    return fNaN;
}

VP_EXPORT double
VpGetDoublePosInf(void) /* Returns the value of +Infinity */
{
    static double fInf = 0.0;
    if(fInf==0.0) fInf = One()/Zero();
    return fInf;
}

VP_EXPORT double
VpGetDoubleNegInf(void) /* Returns the value of -Infinity */
{
    static double fInf = 0.0;
    if(fInf==0.0) fInf = -(One()/Zero());
    return fInf;
}

VP_EXPORT double
VpGetDoubleNegZero(void) /* Returns the value of -0 */
{
    static double nzero = 1000.0;
    if(nzero!=0.0) nzero = (One()/VpGetDoubleNegInf());
    return nzero;
}

#if 0  /* unused */
VP_EXPORT int
VpIsNegDoubleZero(double v)
{
    double z = VpGetDoubleNegZero();
    return MemCmp(&v,&z,sizeof(v))==0;
}
#endif

VP_EXPORT int
VpException(unsigned short f, const char *str,int always)
{
    VALUE exc;
    int   fatal=0;

    if(f==VP_EXCEPTION_OP || f==VP_EXCEPTION_MEMORY) always = 1;

    if(always||(gfDoException&f)) {
        switch(f)
        {
        /*
        case VP_EXCEPTION_OVERFLOW:
        */
        case VP_EXCEPTION_ZERODIVIDE:
        case VP_EXCEPTION_INFINITY:
        case VP_EXCEPTION_NaN:
        case VP_EXCEPTION_UNDERFLOW:
        case VP_EXCEPTION_OP:
             exc = rb_eFloatDomainError;
             goto raise;
        case VP_EXCEPTION_MEMORY:
             fatal = 1;
             goto raise;
        default:
             fatal = 1;
             goto raise;
        }
    }
    return 0; /* 0 Means VpException() raised no exception */

raise:
    if(fatal) rb_fatal("%s", str);
    else   rb_raise(exc, "%s", str);
    return 0;
}

/* Throw exception or returns 0,when resulting c is Inf or NaN */
/*  sw=1:+ 2:- 3:* 4:/ */
static int
VpIsDefOP(Real *c,Real *a,Real *b,int sw)
{
    if(VpIsNaN(a) || VpIsNaN(b)) {
        /* at least a or b is NaN */
        VpSetNaN(c);
        goto NaN;
    }

    if(VpIsInf(a)) {
        if(VpIsInf(b)) {
            switch(sw)
            {
            case 1: /* + */
                if(VpGetSign(a)==VpGetSign(b)) {
                    VpSetInf(c,VpGetSign(a));
                    goto Inf;
                } else {
                    VpSetNaN(c);
                    goto NaN;
                }
            case 2: /* - */
                if(VpGetSign(a)!=VpGetSign(b)) {
                    VpSetInf(c,VpGetSign(a));
                    goto Inf;
                } else {
                    VpSetNaN(c);
                    goto NaN;
                }
                break;
            case 3: /* * */
                VpSetInf(c,VpGetSign(a)*VpGetSign(b));
                goto Inf;
                break;
            case 4: /* / */
                VpSetNaN(c);
                goto NaN;
            }
            VpSetNaN(c);
            goto NaN;
        }
        /* Inf op Finite */
        switch(sw)
        {
        case 1: /* + */
        case 2: /* - */
                VpSetInf(c,VpGetSign(a));
                break;
        case 3: /* * */
                if(VpIsZero(b)) {
                    VpSetNaN(c);
                    goto NaN;
                }
                VpSetInf(c,VpGetSign(a)*VpGetSign(b));
                break;
        case 4: /* / */
                VpSetInf(c,VpGetSign(a)*VpGetSign(b));
        }
        goto Inf;
    }

    if(VpIsInf(b)) {
        switch(sw)
        {
        case 1: /* + */
                VpSetInf(c,VpGetSign(b));
                break;
        case 2: /* - */
                VpSetInf(c,-VpGetSign(b));
                break;
        case 3: /* * */
                if(VpIsZero(a)) {
                    VpSetNaN(c);
                    goto NaN;
                }
                VpSetInf(c,VpGetSign(a)*VpGetSign(b));
                break;
        case 4: /* / */
                VpSetZero(c,VpGetSign(a)*VpGetSign(b));
        }
        goto Inf;
    }
    return 1; /* Results OK */

Inf:
    return VpException(VP_EXCEPTION_INFINITY,"Computation results to 'Infinity'",0);
NaN:
    return VpException(VP_EXCEPTION_NaN,"Computation results to 'NaN'",0);
}

/*
  ----------------------------------------------------------------
*/

/*
 *    returns number of chars needed to represent vp in specified format.
 */
VP_EXPORT U_LONG
VpNumOfChars(Real *vp,const char *pszFmt)
{
    S_INT  ex;
    U_LONG nc;

    if(vp == NULL)   return BASE_FIG*2+6;
    if(!VpIsDef(vp)) return 32; /* not sure,may be OK */

    switch(*pszFmt)
    {
    case 'F':
         nc = BASE_FIG*(vp->Prec + 1)+2;
         ex = vp->exponent;
         if(ex<0) {
             nc += BASE_FIG*(-ex);
         } else {
             if(ex > (S_INT)vp->Prec) {
                 nc += BASE_FIG*(ex - (S_INT)vp->Prec);
             }
         }
         break;
    case 'E':
    default:
         nc = BASE_FIG*(vp->Prec + 2)+6; /* 3: sign + exponent chars */
    }
    return nc;
}

/*
 * Initializer for Vp routines and constants used.
 * [Input]
 *   BaseVal: Base value(assigned to BASE) for Vp calculation.
 *   It must be the form BaseVal=10**n.(n=1,2,3,...)
 *   If Base <= 0L,then the BASE will be calcurated so
 *   that BASE is as large as possible satisfying the
 *   relation MaxVal <= BASE*(BASE+1). Where the value
 *   MaxVal is the largest value which can be represented
 *   by one U_LONG word(LONG) in the computer used.
 *
 * [Returns]
 * DBLE_FIG   ... OK
 */
VP_EXPORT U_LONG
VpInit(U_LONG BaseVal)
{
    /* Setup +/- Inf  NaN -0 */
    VpGetDoubleNaN();
    VpGetDoublePosInf();
    VpGetDoubleNegInf();
    VpGetDoubleNegZero();

#ifndef BASE_FIG
    if(BaseVal <= 0) {
        U_LONG w;
        /* Base <= 0, then determine Base by calcuration. */
        BASE = 1;
        while(
               (BASE > 0) &&
               ((w = BASE *(BASE + 1)) > BASE) &&((w / BASE) ==(BASE + 1))
            ) {
            BaseVal = BASE;
            BASE = BaseVal * 10L;
        }
    }
    /* Set Base Values */
    BASE = BaseVal;
    HALF_BASE = BASE / 2;
    BASE1 = BASE / 10;
    BASE_FIG = 0;
    while(BaseVal /= 10) ++BASE_FIG;
#endif

    /* Allocates Vp constants. */
    VpConstOne = VpAlloc((U_LONG)1, "1");
    VpPt5 = VpAlloc((U_LONG)1, ".5");

#ifdef _DEBUG
    gnAlloc = 0;
#endif /* _DEBUG */

#ifdef _DEBUG
    if(gfDebug) {
        printf("VpInit: BaseVal   = %lu\n", BaseVal);
        printf("  BASE   = %lu\n", BASE);
        printf("  HALF_BASE = %lu\n", HALF_BASE);
        printf("  BASE1  = %lu\n", BASE1);
        printf("  BASE_FIG  = %lu\n", BASE_FIG);
        printf("  DBLE_FIG  = %lu\n", DBLE_FIG);
    }
#endif /* _DEBUG */

    return DBLE_FIG;
}

VP_EXPORT Real *
VpOne(void)
{
    return VpConstOne;
}

/* If exponent overflows,then raise exception or returns 0 */
static int
AddExponent(Real *a,S_INT n)
{
    S_INT e = a->exponent;
    S_INT m = e+n;
    S_INT eb,mb;
    if(e>0) {
        if(n>0) {
            mb = m*BASE_FIG;
            eb = e*BASE_FIG;
            if(mb<eb) goto overflow;
        }
    } else if(n<0) {
        mb = m*BASE_FIG;
        eb = e*BASE_FIG;
        if(mb>eb) goto underflow;
    }
    a->exponent = m;
    return 1;

/* Overflow/Underflow ==> Raise exception or returns 0 */
underflow:
    VpSetZero(a,VpGetSign(a));
    return VpException(VP_EXCEPTION_UNDERFLOW,"Exponent underflow",0);

overflow:
    VpSetInf(a,VpGetSign(a));
    return VpException(VP_EXCEPTION_OVERFLOW,"Exponent overflow",0);
}

/*
 * Allocates variable.
 * [Input]
 *   mx ... allocation unit, if zero then mx is determined by szVal.
 *    The mx is the number of effective digits can to be stored.
 *   szVal ... value assigned(char). If szVal==NULL,then zero is assumed.
 *            If szVal[0]=='#' then Max. Prec. will not be considered(1.1.7),
 *            full precision specified by szVal is allocated.
 *
 * [Returns]
 *   Pointer to the newly allocated variable, or
 *   NULL be returned if memory allocation is failed,or any error.
 */
VP_EXPORT Real *
VpAlloc(U_LONG mx, const char *szVal)
{
    U_LONG i, ni, ipn, ipf, nf, ipe, ne, nalloc;
    char v,*psz;
    int  sign=1;
    Real *vp = NULL;
    U_LONG mf = VpGetPrecLimit();
    volatile VALUE buf;

    mx = (mx + BASE_FIG - 1) / BASE_FIG + 1;    /* Determine allocation unit. */
    if(szVal) {
        while(ISSPACE(*szVal)) szVal++;
        if(*szVal!='#') {
             if(mf) {
                mf = (mf + BASE_FIG - 1) / BASE_FIG + 2; /* Needs 1 more for div */
                if(mx>mf) {
                    mx = mf;
                }
            }
        } else {
            ++szVal;
        }
    } else {
       /* necessary to be able to store */
       /* at least mx digits. */
       /* szVal==NULL ==> allocate zero value. */
       vp = (Real *) VpMemAlloc(sizeof(Real) + mx * sizeof(U_LONG));
       /* xmalloc() alway returns(or throw interruption) */
       vp->MaxPrec = mx;    /* set max precision */
       VpSetZero(vp,1);    /* initialize vp to zero. */
       return vp;
    }

    /* Skip all '_' after digit: 2006-6-30 */
    ni = 0;
    buf = rb_str_new(0,strlen(szVal)+1);
    psz = RSTRING_PTR(buf);
    i   = 0;
    ipn = 0;
    while((psz[i]=szVal[ipn])!=0) {
        if(ISDIGIT(psz[i])) ++ni;
        if(psz[i]=='_') {
            if(ni>0) {ipn++;continue;}
            psz[i]=0;
            break;
        }
        ++i; ++ipn;
    }
    /* Skip trailing spaces */
    while((--i)>0) {
        if(ISSPACE(psz[i])) psz[i] = 0;
        else                break;
    }
    szVal = psz;

    /* Check on Inf & NaN */
    if(StrCmp(szVal,SZ_PINF)==0 ||
       StrCmp(szVal,SZ_INF)==0 ) {
        vp = (Real *) VpMemAlloc(sizeof(Real) + sizeof(U_LONG));
        vp->MaxPrec = 1;    /* set max precision */
        VpSetPosInf(vp);
        return vp;
    }
    if(StrCmp(szVal,SZ_NINF)==0) {
        vp = (Real *) VpMemAlloc(sizeof(Real) + sizeof(U_LONG));
        vp->MaxPrec = 1;    /* set max precision */
        VpSetNegInf(vp);
        return vp;
    }
    if(StrCmp(szVal,SZ_NaN)==0) {
        vp = (Real *) VpMemAlloc(sizeof(Real) + sizeof(U_LONG));
        vp->MaxPrec = 1;    /* set max precision */
        VpSetNaN(vp);
        return vp;
    }

    /* check on number szVal[] */
    ipn = i = 0;
    if     (szVal[i] == '-') {sign=-1;++i;}
    else if(szVal[i] == '+')          ++i;
    /* Skip digits */
    ni = 0;            /* digits in mantissa */
    while((v = szVal[i]) != 0) {
        if(!ISDIGIT(v)) break;
        ++i;
        ++ni;
    }
    nf  = 0;
    ipf = 0;
    ipe = 0;
    ne  = 0;
    if(v) {
        /* other than digit nor \0 */
        if(szVal[i] == '.') {    /* xxx. */
            ++i;
            ipf = i;
            while((v = szVal[i]) != 0) {    /* get fraction part. */
                if(!ISDIGIT(v)) break;
                ++i;
                ++nf;
            }
        }
        ipe = 0;        /* Exponent */

        switch(szVal[i]) {
        case '\0': break;
        case 'e':
        case 'E':
        case 'd':
        case 'D':
            ++i;
            ipe = i;
            v = szVal[i];
            if((v == '-') ||(v == '+')) ++i;
            while((v=szVal[i])!=0) {
                if(!ISDIGIT(v)) break;
                ++i;
                ++ne;
            }
            break;
        default:
            break;
        }
    }
    nalloc =(ni + nf + BASE_FIG - 1) / BASE_FIG + 1;    /* set effective allocation  */
    /* units for szVal[]  */
    if(mx <= 0) mx = 1;
    nalloc = Max(nalloc, mx);
    mx = nalloc;
    vp =(Real *) VpMemAlloc(sizeof(Real) + mx * sizeof(U_LONG));
    /* xmalloc() alway returns(or throw interruption) */
    vp->MaxPrec = mx;        /* set max precision */
    VpSetZero(vp,sign);
    VpCtoV(vp, &(szVal[ipn]), ni, &(szVal[ipf]), nf, &(szVal[ipe]), ne);
    return vp;
}

/*
 * Assignment(c=a).
 * [Input]
 *   a   ... RHSV
 *   isw ... switch for assignment.
 *    c = a  when isw > 0
 *    c = -a when isw < 0
 *    if c->MaxPrec < a->Prec,then round operation
 *    will be performed.
 * [Output]
 *  c  ... LHSV
 */
VP_EXPORT int
VpAsgn(Real *c, Real *a, int isw)
{
    U_LONG n;
    if(VpIsNaN(a)) {
        VpSetNaN(c);
        return 0;
    }
    if(VpIsInf(a)) {
        VpSetInf(c,isw*VpGetSign(a));
        return 0;
    }

    /* check if the RHS is zero */
    if(!VpIsZero(a)) {
        c->exponent = a->exponent;    /* store  exponent */
        VpSetSign(c,(isw*VpGetSign(a)));    /* set sign */
        n =(a->Prec < c->MaxPrec) ?(a->Prec) :(c->MaxPrec);
        c->Prec = n;
        memcpy(c->frac, a->frac, n * sizeof(U_LONG));
        /* Needs round ? */
        if(isw!=10) {
            /* Not in ActiveRound */
            if(c->Prec < a->Prec) {
               VpInternalRound(c,n,(n>0)?a->frac[n-1]:0,a->frac[n]);
            } else {
               VpLimitRound(c,0);
            }
        }
    } else {
        /* The value of 'a' is zero.  */
        VpSetZero(c,isw*VpGetSign(a));
        return 1;
    }
    return c->Prec*BASE_FIG;
}

/*
 *   c = a + b  when operation =  1 or 2
 *  = a - b  when operation = -1 or -2.
 *   Returns number of significant digits of c
 */
VP_EXPORT int
VpAddSub(Real *c, Real *a, Real *b, int operation)
{
    S_INT sw, isw;
    Real *a_ptr, *b_ptr;
    U_LONG n, na, nb, i;
    U_LONG mrv;

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpAddSub(enter) a=% \n", a);
        VPrint(stdout, "     b=% \n", b);
        printf(" operation=%d\n", operation);
    }
#endif /* _DEBUG */

    if(!VpIsDefOP(c,a,b,(operation>0)?1:2)) return 0; /* No significant digits */

    /* check if a or b is zero  */
    if(VpIsZero(a)) {
        /* a is zero,then assign b to c */
        if(!VpIsZero(b)) {
            VpAsgn(c, b, operation);
        } else {
            /* Both a and b are zero. */
            if(VpGetSign(a)<0 && operation*VpGetSign(b)<0) {
                /* -0 -0 */
                VpSetZero(c,-1);
            } else {
                VpSetZero(c,1);
            }
            return 1; /* 0: 1 significant digits */
        }
        return c->Prec*BASE_FIG;
    }
    if(VpIsZero(b)) {
        /* b is zero,then assign a to c. */
        VpAsgn(c, a, 1);
        return c->Prec*BASE_FIG;
    }

    if(operation < 0) sw = -1;
    else              sw =  1;

    /* compare absolute value. As a result,|a_ptr|>=|b_ptr| */
    if(a->exponent > b->exponent) {
        a_ptr = a;
        b_ptr = b;
    }         /* |a|>|b| */
    else if(a->exponent < b->exponent) {
        a_ptr = b;
        b_ptr = a;
    }                /* |a|<|b| */
    else {
        /* Exponent part of a and b is the same,then compare fraction */
        /* part */
        na = a->Prec;
        nb = b->Prec;
        n = Min(na, nb);
        for(i=0;i < n; ++i) {
            if(a->frac[i] > b->frac[i]) {
                a_ptr = a;
                b_ptr = b;
                goto end_if;
            } else if(a->frac[i] < b->frac[i]) {
                a_ptr = b;
                b_ptr = a;
                goto end_if;
            }
        }
        if(na > nb) {
         a_ptr = a;
            b_ptr = b;
            goto end_if;
        } else if(na < nb) {
            a_ptr = b;
            b_ptr = a;
            goto end_if;
        }
        /* |a| == |b| */
        if(VpGetSign(a) + sw *VpGetSign(b) == 0) {
            VpSetZero(c,1);        /* abs(a)=abs(b) and operation = '-'  */
            return c->Prec*BASE_FIG;
        }
        a_ptr = a;
        b_ptr = b;
    }

end_if:
    isw = VpGetSign(a) + sw *VpGetSign(b);
    /*
     *  isw = 0 ...( 1)+(-1),( 1)-( 1),(-1)+(1),(-1)-(-1)
     *      = 2 ...( 1)+( 1),( 1)-(-1)
     *      =-2 ...(-1)+(-1),(-1)-( 1)
     *   If isw==0, then c =(Sign a_ptr)(|a_ptr|-|b_ptr|)
     *              else c =(Sign ofisw)(|a_ptr|+|b_ptr|)
    */
    if(isw) {            /* addition */
        VpSetSign(c,(S_INT)1);
        mrv = VpAddAbs(a_ptr, b_ptr, c);
        VpSetSign(c,isw / 2);
    } else {            /* subtraction */
        VpSetSign(c,(S_INT)1);
        mrv = VpSubAbs(a_ptr, b_ptr, c);
        if(a_ptr == a) {
            VpSetSign(c,VpGetSign(a));
        } else    {
            VpSetSign(c,VpGetSign(a_ptr) * sw);
        }
    }
    VpInternalRound(c,0,(c->Prec>0)?c->frac[c->Prec-1]:0,mrv);

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpAddSub(result) c=% \n", c);
        VPrint(stdout, "     a=% \n", a);
        VPrint(stdout, "     b=% \n", b);
        printf(" operation=%d\n", operation);
    }
#endif /* _DEBUG */
    return c->Prec*BASE_FIG;
}

/*
 * Addition of two variable precisional variables
 * a and b assuming abs(a)>abs(b).
 *   c = abs(a) + abs(b) ; where |a|>=|b|
 */
static U_LONG
VpAddAbs(Real *a, Real *b, Real *c)
{
    U_LONG word_shift;
    U_LONG carry;
    U_LONG ap;
    U_LONG bp;
    U_LONG cp;
    U_LONG a_pos;
    U_LONG b_pos;
    U_LONG c_pos;
    U_LONG av, bv, mrv;

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpAddAbs called: a = %\n", a);
        VPrint(stdout, "     b = %\n", b);
    }
#endif /* _DEBUG */

    word_shift = VpSetPTR(a, b, c, &ap, &bp, &cp, &av, &bv);
    a_pos = ap;
    b_pos = bp;
    c_pos = cp;
    if(word_shift==-1L) return 0; /* Overflow */
    if(b_pos == -1L) goto Assign_a;

    mrv = av + bv; /* Most right val. Used for round. */

    /* Just assign the last few digits of b to c because a has no  */
    /* corresponding digits to be added. */
    while(b_pos + word_shift > a_pos) {
        --c_pos;
        if(b_pos > 0) {
            c->frac[c_pos] = b->frac[--b_pos];
        } else {
            --word_shift;
            c->frac[c_pos] = 0;
        }
    }

    /* Just assign the last few digits of a to c because b has no */
    /* corresponding digits to be added. */
    bv = b_pos + word_shift;
    while(a_pos > bv) {
        c->frac[--c_pos] = a->frac[--a_pos];
    }
    carry = 0;    /* set first carry be zero */

    /* Now perform addition until every digits of b will be */
    /* exhausted. */
    while(b_pos > 0) {
        c->frac[--c_pos] = a->frac[--a_pos] + b->frac[--b_pos] + carry;
        if(c->frac[c_pos] >= BASE) {
            c->frac[c_pos] -= BASE;
            carry = 1;
        } else {
            carry = 0;
        }
    }

    /* Just assign the first few digits of a with considering */
    /* the carry obtained so far because b has been exhausted. */
    while(a_pos > 0) {
        c->frac[--c_pos] = a->frac[--a_pos] + carry;
        if(c->frac[c_pos] >= BASE) {
            c->frac[c_pos] -= BASE;
            carry = 1;
        } else {
            carry = 0;
        }
    }
    if(c_pos) c->frac[c_pos - 1] += carry;
    goto Exit;

Assign_a:
    VpAsgn(c, a, 1);
    mrv = 0;

Exit:

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpAddAbs exit: c=% \n", c);
    }
#endif /* _DEBUG */
    return mrv;
}

/*
 * c = abs(a) - abs(b)
 */
static U_LONG
VpSubAbs(Real *a, Real *b, Real *c)
{
    U_LONG word_shift;
    U_LONG mrv;
    U_LONG borrow;
    U_LONG ap;
    U_LONG bp;
    U_LONG cp;
    U_LONG a_pos;
    U_LONG b_pos;
    U_LONG c_pos;
    U_LONG av, bv;

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpSubAbs called: a = %\n", a);
        VPrint(stdout, "     b = %\n", b);
    }
#endif /* _DEBUG */

    word_shift = VpSetPTR(a, b, c, &ap, &bp, &cp, &av, &bv);
    a_pos = ap;
    b_pos = bp;
    c_pos = cp;
    if(word_shift==-1L) return 0; /* Overflow */
    if(b_pos == -1L) goto Assign_a;

    if(av >= bv) {
        mrv = av - bv;
        borrow = 0;
    } else {
        mrv    = 0;
        borrow = 1;
    }

    /* Just assign the values which are the BASE subtracted by   */
    /* each of the last few digits of the b because the a has no */
    /* corresponding digits to be subtracted. */
    if(b_pos + word_shift > a_pos) {
        while(b_pos + word_shift > a_pos) {
            --c_pos;
            if(b_pos > 0) {
                c->frac[c_pos] = BASE - b->frac[--b_pos] - borrow;
            } else {
                --word_shift;
                c->frac[c_pos] = BASE - borrow;
            }
            borrow = 1;
        }
    }
    /* Just assign the last few digits of a to c because b has no */
    /* corresponding digits to subtract. */

    bv = b_pos + word_shift;
    while(a_pos > bv) {
        c->frac[--c_pos] = a->frac[--a_pos];
    }

    /* Now perform subtraction until every digits of b will be */
    /* exhausted. */
    while(b_pos > 0) {
        --c_pos;
        if(a->frac[--a_pos] < b->frac[--b_pos] + borrow) {
            c->frac[c_pos] = BASE + a->frac[a_pos] - b->frac[b_pos] - borrow;
            borrow = 1;
        } else {
            c->frac[c_pos] = a->frac[a_pos] - b->frac[b_pos] - borrow;
            borrow = 0;
        }
    }

    /* Just assign the first few digits of a with considering */
    /* the borrow obtained so far because b has been exhausted. */
    while(a_pos > 0) {
        --c_pos;
        if(a->frac[--a_pos] < borrow) {
            c->frac[c_pos] = BASE + a->frac[a_pos] - borrow;
            borrow = 1;
        } else {
            c->frac[c_pos] = a->frac[a_pos] - borrow;
            borrow = 0;
        }
    }
    if(c_pos) c->frac[c_pos - 1] -= borrow;
    goto Exit;

Assign_a:
    VpAsgn(c, a, 1);
    mrv = 0;

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpSubAbs exit: c=% \n", c);
    }
#endif /* _DEBUG */
    return mrv;
}

/*
 * Note: If(av+bv)>= HALF_BASE,then 1 will be added to the least significant
 *    digit of c(In case of addition).
 * ------------------------- figure of output -----------------------------------
 *      a =  xxxxxxxxxxx
 *      b =    xxxxxxxxxx
 *      c =xxxxxxxxxxxxxxx
 *      word_shift =  |   |
 *      right_word =  |    | (Total digits in RHSV)
 *      left_word  = |   |   (Total digits in LHSV)
 *      a_pos      =    |
 *      b_pos      =     |
 *      c_pos      =      |
 */
static U_LONG
VpSetPTR(Real *a, Real *b, Real *c, U_LONG *a_pos, U_LONG *b_pos, U_LONG *c_pos, U_LONG *av, U_LONG *bv)
{
    U_LONG left_word, right_word, word_shift;
    c->frac[0] = 0;
    *av = *bv = 0;
    word_shift =((a->exponent) -(b->exponent));
    left_word = b->Prec + word_shift;
    right_word = Max((a->Prec),left_word);
    left_word =(c->MaxPrec) - 1;    /* -1 ... prepare for round up */
    /*
     * check if 'round' is needed.
     */
    if(right_word > left_word) {    /* round ? */
        /*---------------------------------
         *  Actual size of a = xxxxxxAxx
         *  Actual size of b = xxxBxxxxx
         *  Max. size of   c = xxxxxx
         *  Round off        =   |-----|
         *  c_pos            =   |
         *  right_word       =   |
         *  a_pos            =    |
         */
        *c_pos = right_word = left_word + 1;    /* Set resulting precision */
        /* be equal to that of c */
        if((a->Prec) >=(c->MaxPrec)) {
            /*
             *   a =  xxxxxxAxxx
             *   c =  xxxxxx
             *   a_pos =    |
             */
            *a_pos = left_word;
            *av = a->frac[*a_pos];    /* av is 'A' shown in above. */
        } else {
            /*
             *   a = xxxxxxx
             *   c = xxxxxxxxxx
             *  a_pos =     |
             */
            *a_pos = a->Prec;
        }
        if((b->Prec + word_shift) >= c->MaxPrec) {
            /*
             *   a = xxxxxxxxx
             *   b =  xxxxxxxBxxx
             *   c = xxxxxxxxxxx
             *  b_pos =   |
             */
            if(c->MaxPrec >=(word_shift + 1)) {
                *b_pos = c->MaxPrec - word_shift - 1;
                *bv = b->frac[*b_pos];
            } else {
                *b_pos = -1L;
            }
        } else {
            /*
             *   a = xxxxxxxxxxxxxxxx
             *   b =  xxxxxx
             *   c = xxxxxxxxxxxxx
             *  b_pos =     |
             */
            *b_pos = b->Prec;
        }
    } else {            /* The MaxPrec of c - 1 > The Prec of a + b  */
        /*
         *    a =   xxxxxxx
         *    b =   xxxxxx
         *    c = xxxxxxxxxxx
         *   c_pos =   |
         */
        *b_pos = b->Prec;
        *a_pos = a->Prec;
        *c_pos = right_word + 1;
    }
    c->Prec = *c_pos;
    c->exponent = a->exponent;
    if(!AddExponent(c,(S_LONG)1)) return (-1L);
    return word_shift;
}

/*
 * Return number og significant digits
 *       c = a * b , Where a = a0a1a2 ... an
 *             b = b0b1b2 ... bm
 *             c = c0c1c2 ... cl
 *          a0 a1 ... an   * bm
 *       a0 a1 ... an   * bm-1
 *         .   .    .
 *       .   .   .
 *        a0 a1 .... an    * b0
 *      +_____________________________
 *     c0 c1 c2  ......  cl
 *     nc      <---|
 *     MaxAB |--------------------|
 */
VP_EXPORT int
VpMult(Real *c, Real *a, Real *b)
{
    U_LONG MxIndA, MxIndB, MxIndAB, MxIndC;
    U_LONG ind_c, i, ii, nc;
    U_LONG ind_as, ind_ae, ind_bs, ind_be;
    U_LONG Carry, s;
    Real *w;

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpMult(Enter): a=% \n", a);
        VPrint(stdout, "      b=% \n", b);
    }
#endif /* _DEBUG */

    if(!VpIsDefOP(c,a,b,3)) return 0; /* No significant digit */

    if(VpIsZero(a) || VpIsZero(b)) {
        /* at least a or b is zero */
        VpSetZero(c,VpGetSign(a)*VpGetSign(b));
        return 1; /* 0: 1 significant digit */
    }

    if(VpIsOne(a)) {
        VpAsgn(c, b, VpGetSign(a));
        goto Exit;
    }
    if(VpIsOne(b)) {
        VpAsgn(c, a, VpGetSign(b));
        goto Exit;
    }
    if((b->Prec) >(a->Prec)) {
        /* Adjust so that digits(a)>digits(b) */
        w = a;
        a = b;
        b = w;
    }
    w = NULL;
    MxIndA = a->Prec - 1;
    MxIndB = b->Prec - 1;
    MxIndC = c->MaxPrec - 1;
    MxIndAB = a->Prec + b->Prec - 1;

    if(MxIndC < MxIndAB) {    /* The Max. prec. of c < Prec(a)+Prec(b) */
        w = c;
        c = VpAlloc((U_LONG)((MxIndAB + 1) * BASE_FIG), "#0");
        MxIndC = MxIndAB;
    }

    /* set LHSV c info */

    c->exponent = a->exponent;    /* set exponent */
    if(!AddExponent(c,b->exponent)) {
        if(w) VpFree(c);
        return 0;
    }
    VpSetSign(c,VpGetSign(a)*VpGetSign(b));    /* set sign  */
    Carry = 0;
    nc = ind_c = MxIndAB;
    memset(c->frac, 0, (nc + 1) * sizeof(U_LONG));        /* Initialize c  */
    c->Prec = nc + 1;        /* set precision */
    for(nc = 0; nc < MxIndAB; ++nc, --ind_c) {
        if(nc < MxIndB) {    /* The left triangle of the Fig. */
            ind_as = MxIndA - nc;
            ind_ae = MxIndA;
            ind_bs = MxIndB;
            ind_be = MxIndB - nc;
        } else if(nc <= MxIndA) {    /* The middle rectangular of the Fig. */
            ind_as = MxIndA - nc;
            ind_ae = MxIndA -(nc - MxIndB);
            ind_bs = MxIndB;
            ind_be = 0;
        } else if(nc > MxIndA) {    /*  The right triangle of the Fig. */
            ind_as = 0;
            ind_ae = MxIndAB - nc - 1;
            ind_bs = MxIndB -(nc - MxIndA);
            ind_be = 0;
        }

        for(i = ind_as; i <= ind_ae; ++i) {
            s =((a->frac[i]) *(b->frac[ind_bs--]));
            Carry = s / BASE;
            s = s -(Carry * BASE);
            c->frac[ind_c] += s;
            if(c->frac[ind_c] >= BASE) {
                s = c->frac[ind_c] / BASE;
                Carry += s;
                c->frac[ind_c] -= (s * BASE);
            }
            if(Carry) {
                ii = ind_c;
                while((--ii) >= 0) {
                    c->frac[ii] += Carry;
                    if(c->frac[ii] >= BASE) {
                        Carry = c->frac[ii] / BASE;
                        c->frac[ii] -=(Carry * BASE);
                    } else {
                        break;
                    }
                }
            }
        }
    }
    if(w != NULL) {        /* free work variable */
        VpNmlz(c);
        VpAsgn(w, c, 1);
        VpFree(c);
        c = w;
    } else {
        VpLimitRound(c,0);
    }

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpMult(c=a*b): c=% \n", c);
        VPrint(stdout, "      a=% \n", a);
        VPrint(stdout, "      b=% \n", b);
    }
#endif /*_DEBUG */
    return c->Prec*BASE_FIG;
}

/*
 *   c = a / b,  remainder = r
 */
VP_EXPORT int
VpDivd(Real *c, Real *r, Real *a, Real *b)
{
    U_LONG word_a, word_b, word_c, word_r;
    U_LONG i, n, ind_a, ind_b, ind_c, ind_r;
    U_LONG nLoop;
    U_LONG q, b1, b1p1, b1b2, b1b2p1, r1r2;
    U_LONG borrow, borrow1, borrow2, qb;

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, " VpDivd(c=a/b)  a=% \n", a);
        VPrint(stdout, "    b=% \n", b);
    }
#endif /*_DEBUG */

    VpSetNaN(r);
    if(!VpIsDefOP(c,a,b,4)) goto Exit;
    if(VpIsZero(a)&&VpIsZero(b)) {
        VpSetNaN(c);
        return VpException(VP_EXCEPTION_NaN,"(VpDivd) 0/0 not defined(NaN)",0);
    }
    if(VpIsZero(b)) {
        VpSetInf(c,VpGetSign(a)*VpGetSign(b));
        return VpException(VP_EXCEPTION_ZERODIVIDE,"(VpDivd) Divide by zero",0);
    }
    if(VpIsZero(a)) {
        /* numerator a is zero  */
        VpSetZero(c,VpGetSign(a)*VpGetSign(b));
        VpSetZero(r,VpGetSign(a)*VpGetSign(b));
        goto Exit;
    }
    if(VpIsOne(b)) {
        /* divide by one  */
        VpAsgn(c, a, VpGetSign(b));
        VpSetZero(r,VpGetSign(a));
        goto Exit;
    }

    word_a = a->Prec;
    word_b = b->Prec;
    word_c = c->MaxPrec;
    word_r = r->MaxPrec;

    ind_c = 0;
    ind_r = 1;

    if(word_a >= word_r) goto space_error;

    r->frac[0] = 0;
    while(ind_r <= word_a) {
        r->frac[ind_r] = a->frac[ind_r - 1];
        ++ind_r;
    }

    while(ind_r < word_r) r->frac[ind_r++] = 0;
    while(ind_c < word_c) c->frac[ind_c++] = 0;

    /* initial procedure */
    b1 = b1p1 = b->frac[0];
    if(b->Prec <= 1) {
        b1b2p1 = b1b2 = b1p1 * BASE;
    } else {
        b1p1 = b1 + 1;
        b1b2p1 = b1b2 = b1 * BASE + b->frac[1];
        if(b->Prec > 2) ++b1b2p1;
    }

    /* */
    /* loop start */
    ind_c = word_r - 1;
    nLoop = Min(word_c,ind_c);
    ind_c = 1;
    while(ind_c < nLoop) {
        if(r->frac[ind_c] == 0) {
            ++ind_c;
            continue;
        }
        r1r2 = r->frac[ind_c] * BASE + r->frac[ind_c + 1];
        if(r1r2 == b1b2) {
            /* The first two word digits is the same */
            ind_b = 2;
            ind_a = ind_c + 2;
            while(ind_b < word_b) {
                if(r->frac[ind_a] < b->frac[ind_b]) goto div_b1p1;
                if(r->frac[ind_a] > b->frac[ind_b]) break;
                ++ind_a;
                ++ind_b;
            }
            /* The first few word digits of r and b is the same and */
            /* the first different word digit of w is greater than that */
            /* of b, so quotinet is 1 and just subtract b from r. */
            borrow = 0;        /* quotient=1, then just r-b */
            ind_b = b->Prec - 1;
            ind_r = ind_c + ind_b;
            if(ind_r >= word_r) goto space_error;
            n = ind_b;
            for(i = 0; i <= n; ++i) {
                if(r->frac[ind_r] < b->frac[ind_b] + borrow) {
                    r->frac[ind_r] +=(BASE -(b->frac[ind_b] + borrow));
                    borrow = 1;
                } else {
                    r->frac[ind_r] = r->frac[ind_r] - b->frac[ind_b] - borrow;
                    borrow = 0;
                }
                --ind_r;
                --ind_b;
            }
            ++(c->frac[ind_c]);
            goto carry;
        }
        /* The first two word digits is not the same, */
        /* then compare magnitude, and divide actually. */
        if(r1r2 >= b1b2p1) {
            q = r1r2 / b1b2p1;
            c->frac[ind_c] += q;
            ind_r = b->Prec + ind_c - 1;
            goto sub_mult;
        }

div_b1p1:
        if(ind_c + 1 >= word_c) goto out_side;
        q = r1r2 / b1p1;
        c->frac[ind_c + 1] += q;
        ind_r = b->Prec + ind_c;

sub_mult:
        borrow1 = borrow2 = 0;
        ind_b = word_b - 1;
        if(ind_r >= word_r) goto space_error;
        n = ind_b;
        for(i = 0; i <= n; ++i) {
            /* now, perform r = r - q * b */
            qb = q *(b->frac[ind_b]);
            if(qb < BASE) borrow1 = 0;
            else {
                borrow1 = qb / BASE;
                qb = qb - borrow1 * BASE;
            }
            if(r->frac[ind_r] < qb) {
                r->frac[ind_r] +=(BASE - qb);
                borrow2 = borrow2 + borrow1 + 1;
            } else {
                r->frac[ind_r] -= qb;
                borrow2 += borrow1;
            }
            if(borrow2) {
                if(r->frac[ind_r - 1] < borrow2) {
                    r->frac[ind_r - 1] +=(BASE - borrow2);
                    borrow2 = 1;
                } else {
                    r->frac[ind_r - 1] -= borrow2;
                    borrow2 = 0;
                }
            }
            --ind_r;
            --ind_b;
        }

        r->frac[ind_r] -= borrow2;
carry:
        ind_r = ind_c;
        while(c->frac[ind_r] >= BASE) {
            c->frac[ind_r] -= BASE;
            --ind_r;
            ++(c->frac[ind_r]);
        }
    }
    /* End of operation, now final arrangement */
out_side:
    c->Prec = word_c;
    c->exponent = a->exponent;
    if(!AddExponent(c,(S_LONG)2))   return 0;
    if(!AddExponent(c,-(b->exponent))) return 0;

    VpSetSign(c,VpGetSign(a)*VpGetSign(b));
    VpNmlz(c);            /* normalize c */
    r->Prec = word_r;
    r->exponent = a->exponent;
    if(!AddExponent(r,(S_LONG)1)) return 0;
    VpSetSign(r,VpGetSign(a));
    VpNmlz(r);            /* normalize r(remainder) */
    goto Exit;

space_error:
#ifdef _DEBUG
    if(gfDebug) {
        printf("   word_a=%lu\n", word_a);
        printf("   word_b=%lu\n", word_b);
        printf("   word_c=%lu\n", word_c);
        printf("   word_r=%lu\n", word_r);
        printf("   ind_r =%lu\n", ind_r);
    }
#endif /* _DEBUG */
    rb_bug("ERROR(VpDivd): space for remainder too small.");

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, " VpDivd(c=a/b), c=% \n", c);
        VPrint(stdout, "    r=% \n", r);
    }
#endif /* _DEBUG */
    return c->Prec*BASE_FIG;
}

/*
 *  Input  a = 00000xxxxxxxx En(5 preceeding zeros)
 *  Output a = xxxxxxxx En-5
 */
static int
VpNmlz(Real *a)
{
    U_LONG ind_a, i;

    if(!VpIsDef(a)) goto NoVal;
    if(VpIsZero(a)) goto NoVal;

    ind_a = a->Prec;
    while(ind_a--) {
        if(a->frac[ind_a]) {
            a->Prec = ind_a + 1;
            i = 0;
            while(a->frac[i] == 0) ++i;        /* skip the first few zeros */
            if(i) {
                a->Prec -= i;
                if(!AddExponent(a,-((S_INT)i))) return 0;
                memmove(&(a->frac[0]),&(a->frac[i]),(a->Prec)*sizeof(U_LONG));
            }
            return 1;
        }
    }
    /* a is zero(no non-zero digit) */
    VpSetZero(a,VpGetSign(a));
    return 0;

NoVal:
    a->frac[0] = 0;
    a->Prec=1;
    return 0;
}

/*
 *  VpComp = 0  ... if a=b,
 *   Pos  ... a>b,
 *   Neg  ... a<b.
 *   999  ... result undefined(NaN)
 */
VP_EXPORT int
VpComp(Real *a, Real *b)
{
    int val;
    U_LONG mx, ind;
    int e;
    val = 0;
    if(VpIsNaN(a)||VpIsNaN(b)) return 999;
    if(!VpIsDef(a)) {
        if(!VpIsDef(b)) e = a->sign - b->sign;
        else             e = a->sign;
        if(e>0)   return  1;
        else if(e<0) return -1;
        else   return  0;
    }
    if(!VpIsDef(b)) {
        e = -b->sign;
        if(e>0) return  1;
        else return -1;
    }
    /* Zero check */
    if(VpIsZero(a)) {
        if(VpIsZero(b))      return 0; /* both zero */
        val = -VpGetSign(b);
        goto Exit;
    }
    if(VpIsZero(b)) {
        val = VpGetSign(a);
        goto Exit;
    }

    /* compare sign */
    if(VpGetSign(a) > VpGetSign(b)) {
        val = 1;        /* a>b */
        goto Exit;
    }
    if(VpGetSign(a) < VpGetSign(b)) {
        val = -1;        /* a<b */
        goto Exit;
    }

    /* a and b have same sign, && signe!=0,then compare exponent */
    if((a->exponent) >(b->exponent)) {
        val = VpGetSign(a);
        goto Exit;
    }
    if((a->exponent) <(b->exponent)) {
        val = -VpGetSign(b);
        goto Exit;
    }

    /* a and b have same exponent, then compare significand. */
    mx =((a->Prec) <(b->Prec)) ?(a->Prec) :(b->Prec);
    ind = 0;
    while(ind < mx) {
        if((a->frac[ind]) >(b->frac[ind])) {
            val = VpGetSign(a);
         goto Exit;
        }
        if((a->frac[ind]) <(b->frac[ind])) {
            val = -VpGetSign(b);
            goto Exit;
        }
        ++ind;
    }
    if((a->Prec) >(b->Prec)) {
        val = VpGetSign(a);
    } else if((a->Prec) <(b->Prec)) {
        val = -VpGetSign(b);
    }

Exit:
    if  (val> 1) val =  1;
    else if(val<-1) val = -1;

#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, " VpComp a=%\n", a);
        VPrint(stdout, "  b=%\n", b);
        printf("  ans=%d\n", val);
    }
#endif /* _DEBUG */
    return (int)val;
}

#ifdef _DEBUG
/*
 *    cntl_chr ... ASCIIZ Character, print control characters
 *     Available control codes:
 *      %  ... VP variable. To print '%', use '%%'.
 *      \n ... new line
 *      \b ... backspace
 *           ... tab
 *     Note: % must must not appear more than once
 *    a  ... VP variable to be printed
 */
VP_EXPORT int
VPrint(FILE *fp, char *cntl_chr, Real *a)
{
    U_LONG i, j, nc, nd, ZeroSup;
    U_LONG n, m, e, nn;

    /* Check if NaN & Inf. */
    if(VpIsNaN(a)) {
        fprintf(fp,SZ_NaN);
        return 8;
    }
    if(VpIsPosInf(a)) {
        fprintf(fp,SZ_INF);
        return 8;
    }
    if(VpIsNegInf(a)) {
        fprintf(fp,SZ_NINF);
        return 9;
    }
    if(VpIsZero(a)) {
        fprintf(fp,"0.0");
        return 3;
    }

    j = 0;
    nd = nc = 0;        /*  nd : number of digits in fraction part(every 10 digits, */
    /*    nd<=10). */
    /*  nc : number of caracters printed  */
    ZeroSup = 1;        /* Flag not to print the leading zeros as 0.00xxxxEnn */
    while(*(cntl_chr + j)) {
        if((*(cntl_chr + j) == '%') &&(*(cntl_chr + j + 1) != '%')) {
         nc = 0;
         if(!VpIsZero(a)) {
                if(VpGetSign(a) < 0) {
                    fprintf(fp, "-");
                    ++nc;
                }
                nc += fprintf(fp, "0.");
                n = a->Prec;
                for(i=0;i < n;++i) {
                    m = BASE1;
                    e = a->frac[i];
                    while(m) {
                        nn = e / m;
                        if((!ZeroSup) || nn) {
                            nc += fprintf(fp, "%lu", nn);    /* The reading zero(s) */
                            /* as 0.00xx will not */
                            /* be printed. */
                            ++nd;
                            ZeroSup = 0;    /* Set to print succeeding zeros */
                        }
                        if(nd >= 10) {    /* print ' ' after every 10 digits */
                            nd = 0;
                            nc += fprintf(fp, " ");
                        }
                        e = e - nn * m;
                        m /= 10;
                    }
                }
                nc += fprintf(fp, "E%ld", VpExponent10(a));
            } else {
                nc += fprintf(fp, "0.0");
            }
        } else {
            ++nc;
            if(*(cntl_chr + j) == '\\') {
                switch(*(cntl_chr + j + 1)) {
                case 'n':
                    fprintf(fp, "\n");
                    ++j;
                    break;
                case 't':
                    fprintf(fp, "\t");
                    ++j;
                 break;
                case 'b':
                    fprintf(fp, "\n");
                    ++j;
                    break;
                default:
                    fprintf(fp, "%c", *(cntl_chr + j));
                    break;
                }
            } else {
                fprintf(fp, "%c", *(cntl_chr + j));
                if(*(cntl_chr + j) == '%') ++j;
            }
        }
        j++;
    }
    return (int)nc;
}
#endif /* _DEBUG */

static void
VpFormatSt(char *psz,S_INT fFmt)
{
    U_LONG ie;
    U_LONG i;
    S_INT nf = 0;
    char ch;

    if(fFmt<=0) return;

    ie = strlen(psz);
    for(i = 0; i < ie; ++i) {
        ch = psz[i];
        if(!ch) break;
        if(ISSPACE(ch) || ch=='-' || ch=='+') continue;
        if(ch == '.')                { nf = 0;continue;}
        if(ch == 'E') break;
        nf++;
        if(nf > fFmt) {
            memmove(psz + i + 1, psz + i, ie - i + 1);
            ++ie;
            nf = 0;
            psz[i] = ' ';
        }
    }
}

VP_EXPORT S_LONG
VpExponent10(Real *a)
{
    S_LONG ex;
    U_LONG n;

    if(!VpHasVal(a)) return 0;

    ex =(a->exponent) * BASE_FIG;
    n = BASE1;
    while((a->frac[0] / n) == 0) {
         --ex;
         n /= 10;
    }
    return ex;
}

VP_EXPORT void
VpSzMantissa(Real *a,char *psz)
{
    U_LONG i, ZeroSup;
    U_LONG n, m, e, nn;

    if(VpIsNaN(a)) {
        sprintf(psz,SZ_NaN);
        return;
    }
    if(VpIsPosInf(a)) {
        sprintf(psz,SZ_INF);
        return;
    }
    if(VpIsNegInf(a)) {
        sprintf(psz,SZ_NINF);
        return;
    }

    ZeroSup = 1;        /* Flag not to print the leading zeros as 0.00xxxxEnn */
    if(!VpIsZero(a)) {
        if(VpGetSign(a) < 0) *psz++ = '-';
        n = a->Prec;
        for(i=0;i < n;++i) {
            m = BASE1;
            e = a->frac[i];
            while(m) {
                nn = e / m;
                if((!ZeroSup) || nn) {
                    sprintf(psz, "%lu", nn);    /* The reading zero(s) */
                    psz += strlen(psz);
                    /* as 0.00xx will be ignored. */
                    ZeroSup = 0;    /* Set to print succeeding zeros */
                }
                e = e - nn * m;
                m /= 10;
            }
        }
        *psz = 0;
        while(psz[-1]=='0') *(--psz) = 0;
    } else {
        if(VpIsPosZero(a)) sprintf(psz, "0");
        else      sprintf(psz, "-0");
    }
}

VP_EXPORT int
VpToSpecialString(Real *a,char *psz,int fPlus)
/* fPlus =0:default, =1: set ' ' before digits , =2: set '+' before digits. */
{
    if(VpIsNaN(a)) {
        sprintf(psz,SZ_NaN);
        return 1;
    }

    if(VpIsPosInf(a)) {
        if(fPlus==1) {
           *psz++ = ' ';
        } else if(fPlus==2) {
           *psz++ = '+';
        }
        sprintf(psz,SZ_INF);
        return 1;
    }
    if(VpIsNegInf(a)) {
        sprintf(psz,SZ_NINF);
        return 1;
    }
    if(VpIsZero(a)) {
        if(VpIsPosZero(a)) {
            if(fPlus==1)      sprintf(psz, " 0.0");
            else if(fPlus==2) sprintf(psz, "+0.0");
            else              sprintf(psz, "0.0");
        } else    sprintf(psz, "-0.0");
        return 1;
    }
    return 0;
}

VP_EXPORT void
VpToString(Real *a,char *psz,int fFmt,int fPlus)
/* fPlus =0:default, =1: set ' ' before digits , =2:set '+' before digits. */
{
    U_LONG i, ZeroSup;
    U_LONG n, m, e, nn;
    char *pszSav = psz;
    S_LONG ex;

    if(VpToSpecialString(a,psz,fPlus)) return;

    ZeroSup = 1;    /* Flag not to print the leading zeros as 0.00xxxxEnn */

    if(VpGetSign(a) < 0) *psz++ = '-';
    else if(fPlus==1)    *psz++ = ' ';
    else if(fPlus==2)    *psz++ = '+';

    *psz++ = '0';
    *psz++ = '.';
    n = a->Prec;
    for(i=0;i < n;++i) {
        m = BASE1;
        e = a->frac[i];
        while(m) {
            nn = e / m;
            if((!ZeroSup) || nn) {
                sprintf(psz, "%lu", nn);    /* The reading zero(s) */
                psz += strlen(psz);
                /* as 0.00xx will be ignored. */
                ZeroSup = 0;    /* Set to print succeeding zeros */
            }
            e = e - nn * m;
            m /= 10;
        }
    }
    ex =(a->exponent) * BASE_FIG;
    n = BASE1;
    while((a->frac[0] / n) == 0) {
        --ex;
        n /= 10;
    }
    while(psz[-1]=='0') *(--psz) = 0;
    sprintf(psz, "E%ld", ex);
    if(fFmt) VpFormatSt(pszSav, fFmt);
}

VP_EXPORT void
VpToFString(Real *a,char *psz,int fFmt,int fPlus)
/* fPlus =0:default,=1: set ' ' before digits ,set '+' before digits. */
{
    U_LONG i;
    U_LONG n, m, e, nn;
    char *pszSav = psz;
    S_LONG ex;

    if(VpToSpecialString(a,psz,fPlus)) return;

    if(VpGetSign(a) < 0) *psz++ = '-';
    else if(fPlus==1)    *psz++ = ' ';
    else if(fPlus==2)    *psz++ = '+';

    n  = a->Prec;
    ex = a->exponent;
    if(ex<=0) {
       *psz++ = '0';*psz++ = '.';
       while(ex<0) {
          for(i=0;i<BASE_FIG;++i) *psz++ = '0';
          ++ex;
       }
       ex = -1;
    }

    for(i=0;i < n;++i) {
       --ex;
       if(i==0 && ex >= 0) {
           sprintf(psz, "%lu", a->frac[i]);
           psz += strlen(psz);
       } else {
           m = BASE1;
           e = a->frac[i];
           while(m) {
               nn = e / m;
               *psz++ = (char)(nn + '0');
               e = e - nn * m;
               m /= 10;
           }
       }
       if(ex == 0) *psz++ = '.';
    }
    while(--ex>=0) {
       m = BASE;
       while(m/=10) *psz++ = '0';
       if(ex == 0) *psz++ = '.';
    }
    *psz = 0;
    while(psz[-1]=='0') *(--psz) = 0;
    if(psz[-1]=='.') sprintf(psz, "0");
    if(fFmt) VpFormatSt(pszSav, fFmt);
}

/*
 *  [Output]
 *   a[]  ... variable to be assigned the value.
 *  [Input]
 *   int_chr[]  ... integer part(may include '+/-').
 *   ni   ... number of characters in int_chr[],not including '+/-'.
 *   frac[]  ... fraction part.
 *   nf   ... number of characters in frac[].
 *   exp_chr[]  ... exponent part(including '+/-').
 *   ne   ... number of characters in exp_chr[],not including '+/-'.
 */
VP_EXPORT int
VpCtoV(Real *a, const char *int_chr, U_LONG ni, const char *frac, U_LONG nf, const char *exp_chr, U_LONG ne)
{
    U_LONG i, j, ind_a, ma, mi, me;
    U_LONG loc;
    S_INT  e,es, eb, ef;
    S_INT  sign, signe;
    /* get exponent part */
    e = 0;
    ma = a->MaxPrec;
    mi = ni;
    me = ne;
    signe = 1;
    memset(a->frac, 0, ma * sizeof(U_LONG));
    if(ne > 0) {
        i = 0;
        if(exp_chr[0] == '-') {
            signe = -1;
            ++i;
            ++me;
        } else if(exp_chr[0] == '+') {
            ++i;
            ++me;
        }
        while(i < me) {
            es = e*((S_INT)BASE_FIG);
            e = e * 10 + exp_chr[i] - '0';
            if(es>e*((S_INT)BASE_FIG)) {
                VpException(VP_EXCEPTION_INFINITY,"exponent overflow",0);
                sign = 1;
                if(int_chr[0] == '-') sign = -1;
                if(signe > 0) VpSetInf(a, sign);
                else VpSetZero(a, sign);
                return 1;
            }
            ++i;
        }
    }

    /* get integer part */
    i = 0;
    sign = 1;
    if(ni >= 0) {
        if(int_chr[0] == '-') {
            sign = -1;
            ++i;
            ++mi;
        } else if(int_chr[0] == '+') {
            ++i;
            ++mi;
        }
    }

    e = signe * e;        /* e: The value of exponent part. */
    e = e + ni;        /* set actual exponent size. */

    if(e > 0)    signe = 1;
    else        signe = -1;

    /* Adjust the exponent so that it is the multiple of BASE_FIG. */
    j = 0;
    ef = 1;
    while(ef) {
        if(e>=0) eb =  e;
        else  eb = -e;
        ef = eb / ((S_INT)BASE_FIG);
        ef = eb - ef * ((S_INT)BASE_FIG);
        if(ef) {
            ++j;        /* Means to add one more preceeding zero */
            ++e;
        }
    }

    eb = e / ((S_INT)BASE_FIG);

    ind_a = 0;
    while(i < mi) {
        a->frac[ind_a] = 0;
        while((j < (U_LONG)BASE_FIG) &&(i < mi)) {
            a->frac[ind_a] = a->frac[ind_a] * 10 + int_chr[i] - '0';
            ++j;
            ++i;
        }
        if(i < mi) {
            ++ind_a;
            if(ind_a >= ma) goto over_flow;
            j = 0;
        }
    }
    loc = 1;

    /* get fraction part */

    i = 0;
    while(i < nf) {
        while((j < (U_LONG)BASE_FIG) &&(i < nf)) {
            a->frac[ind_a] = a->frac[ind_a] * 10 + frac[i] - '0';
            ++j;
            ++i;
        }
        if(i < nf) {
            ++ind_a;
            if(ind_a >= ma) goto over_flow;
            j = 0;
        }
    }
    goto Final;

over_flow:
    rb_warn("Conversion from String to BigDecimal overflow (last few digits discarded).");

Final:
    if(ind_a >= ma) ind_a = ma - 1;
    while(j < (U_LONG)BASE_FIG) {
        a->frac[ind_a] = a->frac[ind_a] * 10;
        ++j;
    }
    a->Prec = ind_a + 1;
    a->exponent = eb;
    VpSetSign(a,sign);
    VpNmlz(a);
    return 1;
}

/*
 * [Input]
 *   *m  ... Real
 * [Output]
 *   *d  ... fraction part of m(d = 0.xxxxxxx). where # of 'x's is fig.
 *   *e  ... U_LONG,exponent of m.
 * DBLE_FIG ... Number of digits in a double variable.
 *
 *  m -> d*10**e, 0<d<BASE
 * [Returns]
 *   0 ... Zero
 *   1 ... Normal
 *   2 ... Infinity
 *  -1 ... NaN
 */
VP_EXPORT int
VpVtoD(double *d, S_LONG *e, Real *m)
{
    U_LONG ind_m, mm, fig;
    double div;
    int    f = 1;

    if(VpIsNaN(m)) {
        *d = VpGetDoubleNaN();
        *e = 0;
        f = -1; /* NaN */
        goto Exit;
    } else
    if(VpIsPosZero(m)) {
        *d = 0.0;
        *e = 0;
        f  = 0;
        goto Exit;
    } else
    if(VpIsNegZero(m)) {
        *d = VpGetDoubleNegZero();
        *e = 0;
        f  = 0;
        goto Exit;
    } else
    if(VpIsPosInf(m)) {
        *d = VpGetDoublePosInf();
        *e = 0;
        f  = 2;
        goto Exit;
    } else
    if(VpIsNegInf(m)) {
        *d = VpGetDoubleNegInf();
        *e = 0;
        f  = 2;
        goto Exit;
    }
    /* Normal number */
    fig =(DBLE_FIG + BASE_FIG - 1) / BASE_FIG;
    ind_m = 0;
    mm = Min(fig,(m->Prec));
    *d = 0.0;
    div = 1.;
    while(ind_m < mm) {
        div /=(double)((S_INT)BASE);
        *d = *d +((double) ((S_INT)m->frac[ind_m++])) * div;
    }
    *e = m->exponent * ((S_INT)BASE_FIG);
    *d *= VpGetSign(m);

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, " VpVtoD: m=%\n", m);
        printf("   d=%e * 10 **%ld\n", *d, *e);
        printf("   DBLE_FIG = %ld\n", DBLE_FIG);
    }
#endif /*_DEBUG */
    return f;
}

/*
 * m <- d
 */
VP_EXPORT void
VpDtoV(Real *m, double d)
{
    U_LONG i, ind_m, mm;
    U_LONG ne;
    double  val, val2;

    if(isnan(d)) {
        VpSetNaN(m);
        goto Exit;
    }
    if(isinf(d)) {
        if(d>0.0) VpSetPosInf(m);
        else   VpSetNegInf(m);
        goto Exit;
    }

    if(d == 0.0) {
        VpSetZero(m,1);
        goto Exit;
    }
    val =(d > 0.) ? d :(-d);
    ne = 0;
    if(val >= 1.0) {
        while(val >= 1.0) {
            val /=(double)((S_INT)BASE);
            ++ne;
        }
    } else {
        val2 = 1.0 /(double)((S_INT)BASE);
        while(val < val2) {
            val *=(double)((S_INT)BASE);
            --ne;
        }
    }
    /* Now val = 0.xxxxx*BASE**ne */

    mm = m->MaxPrec;
    memset(m->frac, 0, mm * sizeof(U_LONG));
    for(ind_m = 0;val > 0.0 && ind_m < mm;ind_m++) {
        val *=(double)((S_INT)BASE);
        i =(U_LONG) val;
        val -=(double)((S_INT)i);
        m->frac[ind_m] = i;
    }
    if(ind_m >= mm) ind_m = mm - 1;
    if(d > 0.0) {
        VpSetSign(m, (S_INT)1);
    } else {
        VpSetSign(m,-(S_INT)1);
    }
    m->Prec = ind_m + 1;
    m->exponent = ne;

    VpInternalRound(m,0,(m->Prec>0)?m->frac[m->Prec-1]:0,
                      (U_LONG)(val*((double)((S_INT)BASE))));

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        printf("VpDtoV d=%30.30e\n", d);
        VPrint(stdout, "  m=%\n", m);
    }
#endif /* _DEBUG */
    return;
}

/*
 *  m <- ival
 */
#if 0  /* unused */
VP_EXPORT void
VpItoV(Real *m, S_INT ival)
{
    U_LONG mm, ind_m;
    U_LONG val, v1, v2, v;
    int isign;
    S_INT ne;

    if(ival == 0) {
        VpSetZero(m,1);
        goto Exit;
    }
    isign = 1;
    val = ival;
    if(ival < 0) {
        isign = -1;
        val =(U_LONG)(-ival);
    }
    ne = 0;
    ind_m = 0;
    mm = m->MaxPrec;
    while(ind_m < mm) {
        m->frac[ind_m] = 0;
        ++ind_m;
    }
    ind_m = 0;
    while(val > 0) {
        if(val) {
         v1 = val;
         v2 = 1;
            while(v1 >= BASE) {
                v1 /= BASE;
                v2 *= BASE;
            }
            val = val - v2 * v1;
            v = v1;
        } else {
            v = 0;
        }
        m->frac[ind_m] = v;
        ++ind_m;
        ++ne;
    }
    m->Prec = ind_m - 1;
    m->exponent = ne;
    VpSetSign(m,isign);
    VpNmlz(m);

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        printf(" VpItoV i=%d\n", ival);
        VPrint(stdout, "  m=%\n", m);
    }
#endif /* _DEBUG */
    return;
}
#endif

/*
 * y = SQRT(x),  y*y - x =>0
 */
VP_EXPORT int
VpSqrt(Real *y, Real *x)
{
    Real *f = NULL;
    Real *r = NULL;
    S_LONG y_prec, f_prec;
    S_LONG n;
    S_LONG e;
    S_LONG prec;
    S_LONG nr;
    double val;

    /* Zero, NaN or Infinity ? */
    if(!VpHasVal(x)) {
        if(VpIsZero(x)||VpGetSign(x)>0) {
            VpAsgn(y,x,1);
            goto Exit;
        }
        VpSetNaN(y);
        return VpException(VP_EXCEPTION_OP,"(VpSqrt) SQRT(NaN or negative value)",0);
        goto Exit;
    }

     /* Negative ? */
    if(VpGetSign(x) < 0) {
        VpSetNaN(y);
        return VpException(VP_EXCEPTION_OP,"(VpSqrt) SQRT(negative value)",0);
    }

    /* One ? */
    if(VpIsOne(x)) {
        VpSetOne(y);
        goto Exit;
    }

    n = (S_LONG)y->MaxPrec;
    if((S_LONG)x->MaxPrec > n) n = (S_LONG)x->MaxPrec;
    /* allocate temporally variables  */
    f = VpAlloc(y->MaxPrec *(BASE_FIG + 2), "#1");
    r = VpAlloc((n + n) *(BASE_FIG + 2), "#1");

    nr = 0;
    y_prec = (S_LONG)y->MaxPrec;
    f_prec = (S_LONG)f->MaxPrec;

    prec = x->exponent;
    if(prec > 0)    ++prec;
    else            --prec;
    prec = prec - (S_LONG)y->MaxPrec;
    VpVtoD(&val, &e, x);    /* val <- x  */
    e /= ((S_LONG)BASE_FIG);
    n = e / 2;
    if(e - n * 2 != 0) {
        val /=(double)((S_INT)BASE);
        n =(e + 1) / 2;
    }
    VpDtoV(y, sqrt(val));    /* y <- sqrt(val) */
    y->exponent += n;
    n = (DBLE_FIG + BASE_FIG - 1) / BASE_FIG;
    y->MaxPrec = (U_LONG)Min(n , y_prec);
    f->MaxPrec = y->MaxPrec + 1;
    n = y_prec*((S_LONG)BASE_FIG);
    if((U_LONG)n<maxnr) n = (U_LONG)maxnr;
    do {
        y->MaxPrec *= 2;
        if(y->MaxPrec > (U_LONG)y_prec) y->MaxPrec = (U_LONG)y_prec;
        f->MaxPrec = y->MaxPrec;
        VpDivd(f, r, x, y);     /* f = x/y    */
        VpAddSub(r, f, y, -1);  /* r = f - y  */
        VpMult(f, VpPt5, r);    /* f = 0.5*r  */
        if(VpIsZero(f))         goto converge;
        VpAddSub(r, f, y, 1);   /* r = y + f  */
        VpAsgn(y, r, 1);        /* y = r      */
        if(f->exponent <= prec) goto converge;
    } while(++nr < n);
    /* */
#ifdef _DEBUG
    if(gfDebug) {
        printf("ERROR(VpSqrt): did not converge within %ld iterations.\n",
            nr);
    }
#endif /* _DEBUG */
    y->MaxPrec = y_prec;

converge:
    VpChangeSign(y,(S_INT)1);
#ifdef _DEBUG
    if(gfDebug) {
        VpMult(r, y, y);
        VpAddSub(f, x, r, -1);
        printf("VpSqrt: iterations = %lu\n", nr);
        VPrint(stdout, "  y =% \n", y);
        VPrint(stdout, "  x =% \n", x);
        VPrint(stdout, "  x-y*y = % \n", f);
    }
#endif /* _DEBUG */
    y->MaxPrec = y_prec;

Exit:
    VpFree(f);
    VpFree(r);
    return 1;
}

/*
 *
 * nf: digit position for operation.
 *
 */
VP_EXPORT int
VpMidRound(Real *y, int f, int nf)
/*
 * Round reletively from the decimal point.
 *    f: rounding mode
 *   nf: digit location to round from the the decimal point.
 */
{
    /* fracf: any positive digit under rounding position? */
    /* exptoadd: number of digits needed to compensate negative nf */
    int n,i,ix,ioffset,fracf,exptoadd;
    U_LONG v,shifter;
    U_LONG div;

    nf += y->exponent*((int)BASE_FIG);
    exptoadd=0;
    if (nf < 0) {
                /* rounding position too left(large). */
                if((f!=VP_ROUND_CEIL) && (f!=VP_ROUND_FLOOR)) {
                        VpSetZero(y,VpGetSign(y)); /* truncate everything */
                        return 0;
                }
        exptoadd = -nf;
        nf = 0;
    }

    /* ix: x->fraq[ix] contains round position */
    ix = nf/(int)BASE_FIG;
    if(((U_LONG)ix)>=y->Prec) return 0;  /* rounding position too right(small). */
    ioffset = nf - ix*((int)BASE_FIG);

    v = y->frac[ix];

    /* drop digits after pointed digit */
    n = BASE_FIG - ioffset - 1;
    for(shifter=1,i=0;i<n;++i) shifter *= 10;
    fracf = (v%(shifter*10) > 0);
    v /= shifter;
    div = v/10;
    v = v - div*10;
    if (fracf == 0) {
        for(i=ix+1;i<y->Prec;i++) {
            if (y->frac[i]%BASE) {
                fracf = 1;
                break;
            }
        }
    }
    memset(y->frac+ix+1, 0, (y->Prec - (ix+1)) * sizeof(U_LONG));
    switch(f) {
    case VP_ROUND_DOWN: /* Truncate */
         break;
    case VP_ROUND_UP:   /* Roundup */
        if(fracf) ++div;
         break;
    case VP_ROUND_HALF_UP:   /* Round half up  */
        if(v>=5) ++div;
        break;
    case VP_ROUND_HALF_DOWN: /* Round half down  */
        if(v>=6) ++div;
        break;
    case VP_ROUND_CEIL: /* ceil */
        if(fracf && (VpGetSign(y)>0)) ++div;
        break;
    case VP_ROUND_FLOOR: /* floor */
        if(fracf && (VpGetSign(y)<0)) ++div;
        break;
    case VP_ROUND_HALF_EVEN: /* Banker's rounding */
        if(v>5) ++div;
        else if(v==5) {
            if((U_LONG)i==(BASE_FIG-1)) {
                if(ix && (y->frac[ix-1]%2)) ++div;
            } else {
                if(div%2) ++div;
            }
        }
        break;
    }
    for(i=0;i<=n;++i) div *= 10;
    if(div>=BASE) {
        if(ix) {
            y->frac[ix] = 0;
            VpRdup(y,ix);
        } else {
            S_INT s = VpGetSign(y);
            int e = y->exponent;
            VpSetOne(y);
            VpSetSign(y,s);
            y->exponent = e+1;
        }
    } else {
        y->frac[ix] = div;
        VpNmlz(y);
    }
    if (exptoadd > 0) {
        y->exponent += exptoadd/BASE_FIG;
        exptoadd %= BASE_FIG;
        for(i=0;i<exptoadd;i++) {
            y->frac[0] *= 10;
            if (y->frac[0] >= BASE) {
                y->frac[0] /= BASE;
                y->exponent++;
            }
        }
    }
    return 1;
}

VP_EXPORT int
VpLeftRound(Real *y, int f, int nf)
/*
 * Round from the left hand side of the digits.
 */
{
    U_LONG v;
    if(!VpHasVal(y)) return 0; /* Unable to round */
    v = y->frac[0];
    nf -= VpExponent(y)*BASE_FIG;
    while((v /= 10) != 0) nf--;
    nf += (BASE_FIG-1);
    return VpMidRound(y,f,nf);
}

VP_EXPORT int 
VpActiveRound(Real *y, Real *x, int f, int nf)
{
    /* First,assign whole value in truncation mode */
    if(VpAsgn(y, x, 10)<=1) return 0; /* Zero,NaN,or Infinity */
    return VpMidRound(y,f,nf);
}

static int
VpLimitRound(Real *c,U_LONG ixDigit)
{
    U_LONG ix = VpGetPrecLimit();
    if(!VpNmlz(c))    return -1;
    if(!ix)           return 0;
    if(!ixDigit) ixDigit = c->Prec-1;
    if((ix+BASE_FIG-1)/BASE_FIG > ixDigit+1) return 0;
    return VpLeftRound(c,VpGetRoundMode(),ix);
}

static void 
VpInternalRound(Real *c,int ixDigit,U_LONG vPrev,U_LONG v)
{
    int f = 0;

    if(VpLimitRound(c,ixDigit)) return;
    if(!v)                      return;

    v /= BASE1;
    switch(gfRoundMode) {
    case VP_ROUND_DOWN:
        break;
    case VP_ROUND_UP:
        if(v)                    f = 1;
        break;
    case VP_ROUND_HALF_UP:
        if(v >= 5)               f = 1;
        break;
    case VP_ROUND_HALF_DOWN:
        if(v >= 6)               f = 1;
        break;
    case VP_ROUND_CEIL:  /* ceil */
        if(v && (VpGetSign(c)>0)) f = 1;
        break;
    case VP_ROUND_FLOOR: /* floor */
        if(v && (VpGetSign(c)<0)) f = 1;
        break;
    case VP_ROUND_HALF_EVEN:  /* Banker's rounding */
        if(v>5) f = 1;
        else if(v==5 && vPrev%2)  f = 1;
        break;
    }
    if(f) {
        VpRdup(c,ixDigit);    /* round up */
        VpNmlz(c);
    }
}

/*
 *  Rounds up m(plus one to final digit of m).
 */
static int
VpRdup(Real *m,U_LONG ind_m)
{
    U_LONG carry;

    if(!ind_m) ind_m = m->Prec;

    carry = 1;
    while(carry > 0 && (ind_m--)) {
        m->frac[ind_m] += carry;
        if(m->frac[ind_m] >= BASE) m->frac[ind_m] -= BASE;
        else                       carry = 0;
    }
    if(carry > 0) {        /* Overflow,count exponent and set fraction part be 1  */
        if(!AddExponent(m,(S_LONG)1)) return 0;
        m->Prec = m->frac[0] = 1;
    } else {
        VpNmlz(m);
    }
    return 1;
}

/*
 *  y = x - fix(x)
 */
VP_EXPORT void
VpFrac(Real *y, Real *x)
{
    U_LONG my, ind_y, ind_x;

    if(!VpHasVal(x)) {
        VpAsgn(y,x,1);
        goto Exit;
    }

    if(x->exponent > 0 && (U_LONG)x->exponent >= x->Prec) {
        VpSetZero(y,VpGetSign(x));
        goto Exit;
    } else if(x->exponent <= 0) {
        VpAsgn(y, x, 1);
        goto Exit;
    }

    y->Prec = x->Prec -(U_LONG) x->exponent;
    y->Prec = Min(y->Prec, y->MaxPrec);
    y->exponent = 0;
    VpSetSign(y,VpGetSign(x));
    ind_y = 0;
    my = y->Prec;
    ind_x = x->exponent;
    while(ind_y < my) {
        y->frac[ind_y] = x->frac[ind_x];
        ++ind_y;
        ++ind_x;
    }
    VpNmlz(y);

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpFrac y=%\n", y);
        VPrint(stdout, "    x=%\n", x);
    }
#endif /* _DEBUG */
    return;
}

/*
 *   y = x ** n
 */
VP_EXPORT int
VpPower(Real *y, Real *x, S_INT n)
{
    U_LONG s, ss;
    S_LONG sign;
    Real *w1 = NULL;
    Real *w2 = NULL;

    if(VpIsZero(x)) {
        if(n==0) {
           VpSetOne(y);
           goto Exit;
        }
        sign = VpGetSign(x);
        if(n<0) {
           n = -n;
           if(sign<0) sign = (n%2)?(-1):(1);
           VpSetInf (y,sign);
        } else {
           if(sign<0) sign = (n%2)?(-1):(1);
           VpSetZero(y,sign);
        }
        goto Exit;
    }
    if(VpIsNaN(x)) {
        VpSetNaN(y);
        goto Exit;
    }
    if(VpIsInf(x)) {
        if(n==0) {
            VpSetOne(y);
            goto Exit;
        }
        if(n>0) {
            VpSetInf(y, (n%2==0 || VpIsPosInf(x)) ? 1 : -1);
            goto Exit;
        }
        VpSetZero(y, (n%2==0 || VpIsPosInf(x)) ? 1 : -1);
        goto Exit;
    }

    if((x->exponent == 1) &&(x->Prec == 1) &&(x->frac[0] == 1)) {
        /* abs(x) = 1 */
        VpSetOne(y);
        if(VpGetSign(x) > 0) goto Exit;
        if((n % 2) == 0) goto Exit;
        VpSetSign(y,-(S_INT)1);
        goto Exit;
    }

    if(n > 0) sign = 1;
    else if(n < 0) {
        sign = -1;
        n = -n;
    } else {
        VpSetOne(y);
        goto Exit;
    }

    /* Allocate working variables  */

    w1 = VpAlloc((y->MaxPrec + 2) * BASE_FIG, "#0");
    w2 = VpAlloc((w1->MaxPrec * 2 + 1) * BASE_FIG, "#0");
    /* calculation start */

    VpAsgn(y, x, 1);
    --n;
    while(n > 0) {
        VpAsgn(w1, x, 1);
        s = 1;
loop1:  ss = s;
        s += s;
        if(s >(U_LONG) n) goto out_loop1;
        VpMult(w2, w1, w1);
        VpAsgn(w1, w2, 1);
        goto loop1;
out_loop1:
        n -= ss;
        VpMult(w2, y, w1);
        VpAsgn(y, w2, 1);
    }
    if(sign < 0) {
        VpDivd(w1, w2, VpConstOne, y);
        VpAsgn(y, w1, 1);
    }

Exit:
#ifdef _DEBUG
    if(gfDebug) {
        VPrint(stdout, "VpPower y=%\n", y);
        VPrint(stdout, "VpPower x=%\n", x);
        printf("  n=%d\n", n);
    }
#endif /* _DEBUG */
    VpFree(w2);
    VpFree(w1);
    return 1;
}

#ifdef _DEBUG
int
VpVarCheck(Real * v)
/*
 * Checks the validity of the Real variable v.
 * [Input]
 *   v ... Real *, variable to be checked.
 * [Returns]
 *   0  ... correct v.
 *   other ... error
 */
{
    U_LONG i;

    if(v->MaxPrec <= 0) {
        printf("ERROR(VpVarCheck): Illegal Max. Precision(=%lu)\n",
            v->MaxPrec);
        return 1;
    }
    if((v->Prec <= 0) ||((v->Prec) >(v->MaxPrec))) {
        printf("ERROR(VpVarCheck): Illegal Precision(=%lu)\n", v->Prec);
        printf("       Max. Prec.=%lu\n", v->MaxPrec);
        return 2;
    }
    for(i = 0; i < v->Prec; ++i) {
        if((v->frac[i] >= BASE)) {
            printf("ERROR(VpVarCheck): Illegal fraction\n");
            printf("       Frac[%ld]=%lu\n", i, v->frac[i]);
            printf("       Prec.   =%lu\n", v->Prec);
            printf("       Exp. =%d\n", v->exponent);
            printf("       BASE =%lu\n", BASE);
            return 3;
        }
    }
    return 0;
}
#endif /* _DEBUG */

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