Subversion Repositories HelenOS-historic

Rev

Rev 230 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 230 Rev 266
Line 28... Line 28...
28 
 
 28 
 
29 
#include <arch/fmath.h>
 29 
#include <arch/fmath.h>
30 
#include <print.h>
 30 
#include <print.h>
31 
 
 31 
 
32 
#define FMATH_MANTISA_MASK ( 0x000fffffffffffffLL )
 32 
#define FMATH_MANTISA_MASK ( 0x000fffffffffffffLL )
33 
 
 - 
 
34 
int fmath_is_negative(double num)
 33 
#define FMATH_NAN ( 0x0001000000000001LL )
35 
{
 - 
 
36 
    fmath_ld_union_t fmath_ld_union;
 - 
 
37 
    fmath_ld_union.bf = num;
 - 
 
38 
    return ((fmath_ld_union.ldd[7])&0x80)==0x80; /*first bit is sign, IA32 is little endian -> 8th byte*/
 - 
 
39 
 
 - 
 
40 
}
 - 
 
41 
 
 - 
 
42 
signed short fmath_get_binary_exponent(double num)
 34 
signed short fmath_get_binary_exponent(double num)
43 
{
 35 
{
44 
    fmath_ld_union_t fmath_ld_union;
 36 
    fmath_ld_union_t fmath_ld_union;
45 
    fmath_ld_union.bf = num;
 37 
    fmath_ld_union.bf = num;
46 
    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 */
 38 
    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 */
Line 75... Line 67...
75 
   
 67 
   
76 
    exp=fmath_get_binary_exponent(num);
 68 
    exp=fmath_get_binary_exponent(num);
77 
   
 69 
   
78 
    if (exp<0) {
 70 
    if (exp<0) {
79 
        *intp = 0.0;
 71 
        *intp = 0.0;
80 
        *intp = fmath_set_sign(0.0L,fmath_is_negative(num));
 - 
 
81 
        return num;
 72 
        return num;
82 
        }
 73 
        }
83 
       
 74 
       
84 
 
 75 
 
85 
    if (exp>51) {
 76 
    if (exp>51) {
86 
        *intp=num;
 77 
        *intp=num;
87 
        num=0.0;
 78 
        num=0.0;
88 
        num= fmath_set_sign(0.0L,fmath_is_negative(*intp));
 - 
 
89 
        return num;
 79 
        return num;
90 
    }
 80 
    }
91 
   
 81 
   
92 
    fmath_ld_union_num.bf = num;
 82 
    fmath_ld_union_num.bf = num;
93 
   
 83 
   
Line 104... Line 94...
104 
   
 94 
   
105 
    *intp=fmath_ld_union_int.bf;
 95 
    *intp=fmath_ld_union_int.bf;
106 
    return fmath_ld_union_num.bf-fmath_ld_union_int.bf;
 96 
    return fmath_ld_union_num.bf-fmath_ld_union_int.bf;
107 
};
 97 
};
108 
   
 98 
   
109 
double fmath_set_sign(double num,__u8 sign)
 - 
 
110 
{
 - 
 
111 
    fmath_ld_union_t fmath_ld_union;
 - 
 
112 
    fmath_ld_union.bf = num;
 - 
 
113 
    fmath_ld_union.ldd[7]=((fmath_ld_union.ldd[7])&0x7f)|(sign<<7); /* change 64th bit (IA32 is a little endian)*/
 - 
 
114 
    return fmath_ld_union.bf;
 - 
 
115 
}
 - 
 
116 
 
 - 
 
117 
double fmath_abs(double num)
 - 
 
118 
{
 - 
 
119 
    return fmath_set_sign(num,0);
 - 
 
120 
}
 - 
 
121 
 
 99 
 
122 
double fmath_dpow(double base, double exponent)
 100 
double fmath_dpow(double base, double exponent)
123 
{
 101 
{
124 
    double value=1.0;
 102 
    double value=1.0;
125 
    if (base<=0.0) return base;
 103 
    if (base<=0.0) return base;
Line 139... Line 117...
139 
        "fstp %%st(1) \n\t"     \
 117 
        "fstp %%st(1) \n\t"     \
140 
    "" : "=t" (value) :  "0" (base), "u" (exponent) );
 118 
    "" : "=t" (value) :  "0" (base), "u" (exponent) );
141 
    return value;
 119 
    return value;
142 
}
 120 
}
143 
 
 121 
 
- 
 
 122 
int fmath_is_nan(double num)
- 
 
 123 
{
- 
 
 124 
    __u16 exp;
- 
 
 125 
    fmath_ld_union_t fmath_ld_union;
- 
 
 126 
    fmath_ld_union.bf = num;
- 
 
 127 
    exp=(((fmath_ld_union.ldd[7])&0x7f)<<4) + (((fmath_ld_union.ldd[6])&0xf0)>>4); /* exponent is 11 bits lenght, so sevent bits is in 8th byte and 4 bits in 7th */
- 
 
 128 
 
- 
 
 129 
    if (exp!=0x07ff) return 0;
- 
 
 130 
    if (fmath_get_binary_mantisa(num)>=FMATH_NAN) return 1;
- 
 
 131 
   
- 
 
 132 
       
- 
 
 133 
    return 0;
- 
 
 134 
}
- 
 
 135 
 
- 
 
 136 
int fmath_is_infinity(double num)
- 
 
 137 
{
- 
 
 138 
    __u16 exp;
- 
 
 139 
    fmath_ld_union_t fmath_ld_union;
- 
 
 140 
    fmath_ld_union.bf = num;
- 
 
 141 
    exp=(((fmath_ld_union.ldd[7])&0x7f)<<4) + (((fmath_ld_union.ldd[6])&0xf0)>>4); /* exponent is 11 bits lenght, so sevent bits is in 8th byte and 4 bits in 7th */
- 
 
 142 
 
- 
 
 143 
    if (exp!=0x07ff) return 0;
- 
 
 144 
    if (fmath_get_binary_mantisa(num)==0x0) return 1;
- 
 
 145 
    return 0;
- 
 
 146 
}