+ /* Use 'double' operations.
+ Assumes an IEEE 754 'double' implementation. */
+# define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7)
+# define DBL_EXP_BIAS (DBL_EXP_MASK / 2 - 1)
+# define NWORDS \
+ ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+ union { double value; unsigned int word[NWORDS]; } m;
+
+ /* Use a single integer to floating-point conversion. */
+ m.value = msd;
+
+ s = GMP_LIMB_BITS
+ - (((m.word[DBL_EXPBIT0_WORD] >> DBL_EXPBIT0_BIT) & DBL_EXP_MASK)
+ - DBL_EXP_BIAS);