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  1. /*
  2.  * Copyright (C) 2005 Josef Cejka
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #include <arch/fmath.h>
  30. #include <print.h>
  31.  
  32.     //TODO:
  33. #define FMATH_MANTISA_MASK ( 0x000fffffffffffffLL )
  34.  
  35. int fmath_is_negative(double num)
  36. {   //TODO:
  37. /*  fmath_ld_union_t fmath_ld_union;
  38.     fmath_ld_union.bf = num;
  39.     return ((fmath_ld_union.ldd[7])&0x80)==0x80; //first bit is sign, IA32 is little endian -> 8th byte
  40. */
  41.     return 0;
  42. }
  43.  
  44. signed short fmath_get_binary_exponent(double num)
  45. {   //TODO:
  46. /*  fmath_ld_union_t fmath_ld_union;
  47.     fmath_ld_union.bf = num;
  48.     return (signed short)((((fmath_ld_union.ldd[7])&0x7f)<<4) + (((fmath_ld_union.ldd[6])&0xf0)>>4)) -FMATH_EXPONENT_BIAS; // exponent is 11 bits lenght, so sevent bits is in 8th byte and 4 bits in 7th
  49. */
  50.     return 0;
  51. }
  52.  
  53. double fmath_get_decimal_exponent(double num)
  54. {   //TODO:
  55.     double value;
  56.     // log10(2)*log2(x) => log10(x)
  57. /*  __asm__ __volatile__ ( \
  58.     "fldlg2     #load log10(2)  \n\t"   \
  59.     "fxch %%st(1)       \n\t" \
  60.     "fyl2x      #count st(0)*log2(st(1))->st(1); pop st(0)  \n\t" \
  61.     : "=t" (value) : "0"(num) );
  62. */  return value;
  63.    
  64. }
  65.  
  66. __u64 fmath_get_binary_mantisa(double num)
  67. {   //TODO:
  68. /*  union { __u64 _u; double _d;} un = { _d : num };
  69.     un._u=un._u &(FMATH_MANTISA_MASK); // mask 52 bits of mantisa
  70.     return un._u;
  71.     */
  72.     return 0;
  73. }
  74.  
  75. double fmath_fint(double num, double *intp)
  76. {   //TODO:
  77. /*  fmath_ld_union_t fmath_ld_union_num;
  78.     fmath_ld_union_t fmath_ld_union_int;
  79.     signed short exp;
  80.     __u64 mask,mantisa;
  81.     int i;
  82.    
  83.     exp=fmath_get_binary_exponent(num);
  84.    
  85.     if (exp<0) {
  86.         *intp = 0.0;
  87.         *intp = fmath_set_sign(0.0L,fmath_is_negative(num));
  88.         return num;
  89.         }
  90.        
  91.  
  92.     if (exp>51) {
  93.         *intp=num;
  94.         num=0.0;
  95.         num= fmath_set_sign(0.0L,fmath_is_negative(*intp));
  96.         return num;
  97.     }
  98.    
  99.     fmath_ld_union_num.bf = num;
  100.    
  101.     mask = FMATH_MANTISA_MASK>>exp;
  102.     //mantisa = (fmath_get-binary_mantisa(num))&(~mask);
  103.    
  104.     for (i=0;i<7;i++) {
  105.         // Ugly construction for obtain sign, exponent and integer part from num
  106.         fmath_ld_union_int.ldd[i]=fmath_ld_union_num.ldd[i]&(((~mask)>>(i*8))&0xff);
  107.     }
  108.    
  109.     fmath_ld_union_int.ldd[6]|=((fmath_ld_union_num.ldd[6])&(0xf0));
  110.     fmath_ld_union_int.ldd[7]=fmath_ld_union_num.ldd[7];
  111.    
  112.     *intp=fmath_ld_union_int.bf;
  113.     return fmath_ld_union_num.bf-fmath_ld_union_int.bf;
  114. */
  115.    
  116.     return 0.0;
  117. };
  118.    
  119. double fmath_set_sign(double num,__u8 sign)
  120. {   //TODO:
  121. /*  fmath_ld_union_t fmath_ld_union;
  122.     fmath_ld_union.bf = num;
  123.     fmath_ld_union.ldd[7]=((fmath_ld_union.ldd[7])&0x7f)|(sign<<7); // change 64th bit (IA32 is a little endian)
  124.     return fmath_ld_union.bf;
  125. */  return 1.0;
  126. }
  127.  
  128. double fmath_abs(double num)
  129. {   //TODO:
  130. /*
  131.     return fmath_set_sign(num,0);
  132. */
  133.     return 1.0;
  134. }
  135.  
  136. double fmath_dpow(double base, double exponent)
  137. {   //TODO:
  138. /*  double value=1.0;
  139.     if (base<=0.0) return base;
  140.    
  141.     //2^(x*log2(10)) = 2^y = 10^x
  142.    
  143.     __asm__ __volatile__ (      \
  144.         "fyl2x # ST(1):=ST(1)*log2(ST(0)), pop st(0) \n\t "     \
  145.         "fld    %%st(0) \n\t"   \
  146.         "frndint \n\t"      \
  147.         "fxch %%st(1) \n\t"     \
  148.         "fsub %%st(1),%%st(0) \n\t" \
  149.         "f2xm1  # ST := 2^ST -1\n\t"            \
  150.         "fld1 \n\t"         \
  151.         "faddp %%st(0),%%st(1) \n\t"    \
  152.         "fscale #ST:=ST*2^(ST(1))\n\t"      \
  153.         "fstp %%st(1) \n\t"     \
  154.     "" : "=t" (value) :  "0" (base), "u" (exponent) );
  155.     return value;
  156. */
  157.     return 1.0;
  158. }
  159.  
  160.