libk/src/math/copysign.c


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#include <math.h>
#include <stdint.h>

#define DMASK 0x8000000000000000

double copysign(double n, double s) {
	union {double f; uint64_t i;} sb = {s};
	union {double f; uint64_t i;} nb = {n};
    nb.i = (nb.i & ~DMASK) | (sb.i & DMASK);
	return nb.f;
}

#define FMASK 0x80000000

float copysignf(float n, float s) {
	union {float f; uint32_t i;} sb = {s};
	union {float f; uint32_t i;} nb = {n};
    nb.i = (nb.i & ~FMASK) | (sb.i & FMASK);
	return nb.f;
}