mandelbrot/doubledouble.h
2013-06-28 09:09:55 +02:00

147 lines
3.8 KiB
C

#include <math.h>
typedef struct {
double hi;
double lo;
} DoubleDouble;
inline DoubleDouble dd_new(double hi, double lo) {
DoubleDouble num;
num.hi = hi;
num.lo = lo;
return num;
}
unsigned int dd_get_ui(DoubleDouble num) {
return num.hi;
}
inline DoubleDouble dd_sqrt(DoubleDouble num) {
double a, b, c, d, e;
d = 1 / sqrt(num.hi);
e = num.hi * d;
a = 0x08000001 * e;
a += e - a;
b = e - a;
c = e * e;
b = ((a * a - c) + a * b * 2) + b * b;
a = num.hi - c;
c = num.hi - a;
c = (a + ((((num.hi - (c + a)) + (c - c)) + num.lo) - b)) * d * 0.5;
a = e + c;
b = e - a;
return dd_new(a, (e - (b + a)) + (b + c));
}
inline DoubleDouble dd_div(DoubleDouble num1, DoubleDouble num2) {
double a, b, c, d, e, f, g;
f = num1.hi / num2.hi;
a = 0x08000001 * num2.hi;
a += num2.hi - a;
b = num2.hi - a;
c = 0x08000001 * f;
c += f - c;
d = f - c;
e = num2.hi * f;
c = (((a * c - e) + (a * d + b * c)) + b * d) + num2.lo * f;
b = num1.lo - c;
d = num1.lo - b;
a = num1.hi - e;
e = (num1.hi - ((num1.hi - a) + a)) + b;
g = a + e;
e += (a - g) + ((num1.lo - (d + b)) + (d - c));
a = g + e;
b = a / num2.hi;
f += (e + (g - a)) / num2.hi;
a = f + b;
return dd_new(a, b + (f - a));
}
inline DoubleDouble dd_ui_div(unsigned int num1, DoubleDouble num2) {
return dd_div(dd_new(num1, 0), num2);
}
inline DoubleDouble dd_div_ui(DoubleDouble num1, unsigned int num2) {
return dd_div(num1, dd_new(num2, 0));
}
inline DoubleDouble dd_si_div(signed int num1, DoubleDouble num2) {
return dd_div(dd_new(num1, 0), num2);
}
inline DoubleDouble dd_div_si(DoubleDouble num1, signed int num2) {
return dd_div(num1, dd_new(num2, 0));
}
inline DoubleDouble dd_add(DoubleDouble num1, DoubleDouble num2) {
double a, b, c, d, e, f;
e = num1.hi + num2.hi;
d = num1.hi - e;
a = num1.lo + num2.lo;
f = num1.lo - a;
d = ((num1.hi - (d + e)) + (d + num2.hi)) + a;
b = e + d;
c = ((num1.lo - (f + a)) + (f + num2.lo)) + (d + (e - b));
a = b + c;
return dd_new(a, c + (b - a));
}
inline DoubleDouble dd_mul(DoubleDouble num1, DoubleDouble num2) {
double a, b, c, d, e;
a = 0x08000001 * num1.hi;
a += num1.hi - a;
b = num1.hi - a;
c = 0x08000001 * num2.hi;
c += num2.hi - c;
d = num2.hi - c;
e = num1.hi * num2.hi;
c = (((a * c - e) + (a * d + b * c)) + b * d) + (num1.lo * num2.hi + num1.hi * num2.lo);
a = e + c;
return dd_new(a, c + (e - a));
}
inline DoubleDouble dd_mul2(DoubleDouble num1, DoubleDouble num2) {
double a, b, c, d, e;
a = 0x08000001 * num1.hi;
a += num1.hi - a;
b = num1.hi - a;
c = 0x08000001 * num2.hi;
c += num2.hi - c;
d = num2.hi - c;
e = num1.hi * num2.hi;
c = 2*((((a * c - e) + (a * d + b * c)) + b * d) + (num1.lo * num2.hi + num1.hi * num2.lo));
a = 2*e + c;
return dd_new(a, c + (2*e - a));
}
inline DoubleDouble dd_mul_ui(DoubleDouble num1, unsigned int num2) {
return dd_mul(num1, dd_new(num2, 0));
}
inline DoubleDouble dd_mul_d(DoubleDouble num1, double num2) {
return dd_mul(num1, dd_new(num2, 0));
}
inline DoubleDouble dd_sub(DoubleDouble num1, DoubleDouble num2) {
double a, b, c, d, e, f, g;
g = num1.lo - num2.lo;
f = num1.lo - g;
e = num1.hi - num2.hi;
d = num1.hi - e;
d = ((num1.hi - (d + e)) + (d - num2.hi)) + g;
b = e + d;
c = (d + (e - b)) + ((num1.lo - (f + g)) + (f - num2.lo));
a = b + c;
return dd_new(a, c + (b - a));
}
inline DoubleDouble dd_sqr(DoubleDouble num) {
double a, b, c;
a = 0x08000001 * num.hi;
a += num.hi - a;
b = num.hi - a;
c = num.hi * num.hi;
b = ((((a * a - c) + a * b * 2) + b * b) + num.hi * num.lo * 2) + num.lo * num.lo;
a = b + c;
return dd_new(a, b + (c - a));
}