| 0,0 → 1,26 |
|---|
| /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| #include <math.h> |
| |
| double |
| frexp(double x, int *exptr) |
| { |
| union { |
| double d; |
| unsigned char c[8]; |
| } u; |
| |
| u.d = x; |
| /* |
| * The format of the number is: |
| * Sign, 12 exponent bits, 51 mantissa bits |
| * The exponent is 1023 biased and there is an implicit zero. |
| * We get the exponent from the upper bits and set the exponent |
| * to 0x3fe (1022). |
| */ |
| *exptr = (int)(((u.c[7] & 0x7f) << 4) | (u.c[6] >> 4)) - 1022; |
| u.c[7] &= 0x80; |
| u.c[7] |= 0x3f; |
| u.c[6] &= 0x0f; |
| u.c[6] |= 0xe0; |
| return u.d; |
| } |