diff options
Diffstat (limited to 'stdlib/erand48_r.c')
| -rw-r--r-- | stdlib/erand48_r.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/stdlib/erand48_r.c b/stdlib/erand48_r.c index a2a0f58c14..958c2e2799 100644 --- a/stdlib/erand48_r.c +++ b/stdlib/erand48_r.c @@ -17,6 +17,7 @@ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +#include <ieee754.h> #include <stdlib.h> #include <limits.h> @@ -27,6 +28,8 @@ erand48_r (xsubi, buffer, result) struct drand48_data *buffer; double *result; { + union ieee754_double temp; + /* Compute next state. */ if (__drand48_iterate (xsubi, buffer) < 0) return -1; @@ -35,9 +38,12 @@ erand48_r (xsubi, buffer, result) its fractional part so the resulting FP number is [0.0,1.0). */ #if USHRT_MAX == 65535 - *result = ((double) xsubi[2] / (1ULL << 48) + - (double) xsubi[1] / (1ULL << 32) + - (double) xsubi[0] / (1ULL << 16)); + temp.ieee.negative = 0; + temp.ieee.exponent = IEEE754_DOUBLE_BIAS - 1; + temp.ieee.mantissa0 = (xsubi[2] << 4) | (xsubi[1] >> 12); + temp.ieee.mantissa1 = ((xsubi[1] & 0xfff) << 20) | (xsubi[0] << 4); + /* Please note the lower 4 bits of mantissa1 are always 0. */ + *result = temp.d; #else # error Unsupported size of short int #endif |