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-rw-r--r--stdlib/erand48_r.c12
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