toaruos/libc/math/frexp.c
2018-06-25 12:11:33 +09:00

26 lines
445 B
C

#include <string.h>
#include <stdint.h>
double frexp(double x, int *exp) {
struct {
uint32_t lsw;
uint32_t msw;
} extract;
memcpy(&extract, &x, sizeof(double));
*exp = ((extract.msw & 0x7ff00000) >> 20) - 0x3FE;
struct {
uint32_t lsw;
uint32_t msw;
} out_double;
out_double.msw = (extract.msw & 0x800fffff) | 0x3FE00000;
out_double.lsw = extract.lsw;
double out;
memcpy(&out, &out_double, sizeof(double));
return out;
}