#include "Python.h"

#ifdef X87_DOUBLE_ROUNDING

/* On x86 platforms using an x87 FPU, this function is called from the

Py_FORCE_DOUBLE macro (defined in pymath.h) to force a floating-point

number out of an 80-bit x87 FPU register and into a 64-bit memory location,

thus rounding from extended precision to double precision. */

double _Py_force_double(double x)

{

volatile double y;

y = x;

return y;

}

#endif

#ifdef HAVE_GCC_ASM_FOR_X87

/* inline assembly for getting and setting the 387 FPU control word on

gcc/x86 */

unsigned short _Py_get_387controlword(void) {

unsigned short cw;

__asm__ __volatile__ ("fnstcw %0" : "=m" (cw));

return cw;

}

void _Py_set_387controlword(unsigned short cw) {

__asm__ __volatile__ ("fldcw %0" : : "m" (cw));

}

#endif

#ifndef HAVE_HYPOT

double hypot(double x, double y)

{

double yx;

x = fabs(x);

y = fabs(y);

if (x < y) {

double temp = x;

x = y;

y = temp;

}

if (x == 0.)

return 0.;

else {

yx = y/x;

return x*sqrt(1.+yx*yx);

}

}

#endif /* HAVE_HYPOT */

#ifndef HAVE_COPYSIGN

double

copysign(double x, double y)

{

/* use atan2 to distinguish -0. from 0. */

if (y > 0. || (y == 0. && atan2(y, -1.) > 0.)) {

return fabs(x);

} else {

return -fabs(x);

}

}

#endif /* HAVE_COPYSIGN */

#ifndef HAVE_ROUND

double

round(double x)

{

double absx, y;

absx = fabs(x);

y = floor(absx);

if (absx - y >= 0.5)

y += 1.0;

return copysign(y, x);

}

#endif /* HAVE_ROUND */