utils/ipmitool/patches/100-cubic_root.patch

   1 --- ipmitool-1.8.9/lib/ipmi_sdr.c.orig  2007-07-16 13:09:13.000000000 +0200
   2 +++ ipmitool-1.8.9/lib/ipmi_sdr.c       2007-07-16 13:09:20.000000000 +0200
   3 @@ -4264,3 +4264,144 @@
   4
   5         return rc;
   6  }
   7 +
   8 +/*                                                     cbrt.c
   9 + *
  10 + *     Cube root
  11 + *
  12 + *
  13 + *
  14 + * SYNOPSIS:
  15 + *
  16 + * double x, y, cbrt();
  17 + *
  18 + * y = cbrt( x );
  19 + *
  20 + *
  21 + *
  22 + * DESCRIPTION:
  23 + *
  24 + * Returns the cube root of the argument, which may be negative.
  25 + *
  26 + * Range reduction involves determining the power of 2 of
  27 + * the argument.  A polynomial of degree 2 applied to the
  28 + * mantissa, and multiplication by the cube root of 1, 2, or 4
  29 + * approximates the root to within about 0.1%.  Then Newton's
  30 + * iteration is used three times to converge to an accurate
  31 + * result.
  32 + *
  33 + *
  34 + *
  35 + * ACCURACY:
  36 + *
  37 + *                      Relative error:
  38 + * arithmetic   domain     # trials      peak         rms
  39 + *    DEC        -10,10     200000      1.8e-17     6.2e-18
  40 + *    IEEE       0,1e308     30000      1.5e-16     5.0e-17
  41 + *
  42 + */
  43 +/*                                                     cbrt.c  */
  44 +
  45 +/*
  46 +Cephes Math Library Release 2.8:  June, 2000
  47 +Copyright 1984, 1991, 2000 by Stephen L. Moshier
  48 +*/
  49 +
  50 +
  51 +static double CBRT2  = 1.2599210498948731647672;
  52 +static double CBRT4  = 1.5874010519681994747517;
  53 +static double CBRT2I = 0.79370052598409973737585;
  54 +static double CBRT4I = 0.62996052494743658238361;
  55 +
  56 +#ifdef ANSIPROT
  57 +extern double frexp ( double, int * );
  58 +extern double ldexp ( double, int );
  59 +extern int isnan ( double );
  60 +extern int isfinite ( double );
  61 +#else
  62 +double frexp(), ldexp();
  63 +int isnan(), isfinite();
  64 +#endif
  65 +
  66 +double cbrt(x)
  67 +double x;
  68 +{
  69 +int e, rem, sign;
  70 +double z;
  71 +
  72 +#ifdef NANS
  73 +if( isnan(x) )
  74 +  return x;
  75 +#endif
  76 +#ifdef INFINITIES
  77 +if( !isfinite(x) )
  78 +  return x;
  79 +#endif
  80 +if( x == 0 )
  81 +       return( x );
  82 +if( x > 0 )
  83 +       sign = 1;
  84 +else
  85 +       {
  86 +       sign = -1;
  87 +       x = -x;
  88 +       }
  89 +
  90 +z = x;
  91 +/* extract power of 2, leaving
  92 + * mantissa between 0.5 and 1
  93 + */
  94 +x = frexp( x, &e );
  95 +
  96 +/* Approximate cube root of number between .5 and 1,
  97 + * peak relative error = 9.2e-6
  98 + */
  99 +x = (((-1.3466110473359520655053e-1  * x
 100 +      + 5.4664601366395524503440e-1) * x
 101 +      - 9.5438224771509446525043e-1) * x
 102 +      + 1.1399983354717293273738e0 ) * x
 103 +      + 4.0238979564544752126924e-1;
 104 +
 105 +/* exponent divided by 3 */
 106 +if( e >= 0 )
 107 +       {
 108 +       rem = e;
 109 +       e /= 3;
 110 +       rem -= 3*e;
 111 +       if( rem == 1 )
 112 +               x *= CBRT2;
 113 +       else if( rem == 2 )
 114 +               x *= CBRT4;
 115 +       }
 116 +
 117 +
 118 +/* argument less than 1 */
 119 +
 120 +else
 121 +       {
 122 +       e = -e;
 123 +       rem = e;
 124 +       e /= 3;
 125 +       rem -= 3*e;
 126 +       if( rem == 1 )
 127 +               x *= CBRT2I;
 128 +       else if( rem == 2 )
 129 +               x *= CBRT4I;
 130 +       e = -e;
 131 +       }
 132 +
 133 +/* multiply by power of 2 */
 134 +x = ldexp( x, e );
 135 +
 136 +/* Newton iteration */
 137 +x -= ( x - (z/(x*x)) )*0.33333333333333333333;
 138 +#ifdef DEC
 139 +x -= ( x - (z/(x*x)) )/3.0;
 140 +#else
 141 +x -= ( x - (z/(x*x)) )*0.33333333333333333333;
 142 +#endif
 143 +
 144 +if( sign < 0 )
 145 +       x = -x;
 146 +return(x);
 147 +}