kolibrios-fun/programs/develop/ktcc/trunk/libc/math/fmod.c

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#include <math.h>
double remainder(double numer, double denom)
{
double res;
asm("fldl %2;"
"fldl %1;"
"fprem1;"
"fstpl %0;"
"fstp %%st;"
: "=m"(res)
: "m"(numer), "m"(denom)
);
return res;
}
//remainder of 5.3 / 2 is -0.700000
//remainder of 18.5 / 4.2 is 1.700000
double fmod(double numer, double denom)
{
double res;
asm("fldl %2;"
"fldl %1;"
"fprem;"
"fstpl %0;"
"fstp %%st;"
: "=m"(res)
: "m"(numer), "m"(denom)
);
return res;
}
// fmod of 5.3 / 2 is 1.300000
// fmod of 18.5 / 4.2 is 1.700000
double modf(double x, double *intpart)
{
double res, intp;
asm("fldl %2;"
"fldl %2;"
"frndint;"
"fstl %1;"
"fxch;"
"fsubp %%st, %%st(1);"
"fstpl %0"
: "=m"(res), "=m"(intp)
: "m"(x)
);
*intpart = intp;
return res;
}
double ldexp (double x, int expon)
// = x * 2^expot
{
double res;
asm("fildl %2;"
"fldl %1;"
"fscale;"
"fstpl %0;"
"fstp %%st;"
: "=m"(res)
: "m"(x), "m"(expon)
);
return res;
}
double frexp (double x, int* expon)
{
double res;
asm("fldl %2;"
"fxtract;"
"fstpl %0;"
"fistpl %1;"
"fstp %%st;"
: "=m"(res), "=m"(*expon)
: "m"(x)
);
// *expon = (int)ex;
return res;
}
// 8.000000 = 0.500000 * 2^ 4