- /* Note that if exponent indicates a NaN, we can't really do anything useful
- (not knowing if the host has NaN's, or how to build one). So it will
- end up as an infinity or something close; that is OK. */
+
+ /* If the exponent indicates a NaN, we don't have information to
+ decide what to do. So we handle it like IEEE, except that we
+ don't try to preserve the type of NaN. FIXME. */
+ if ((unsigned long) exponent == fmt->exp_nan)
+ {
+ int nan;
+
+ mant_off = fmt->man_start;
+ mant_bits_left = fmt->man_len;
+ nan = 0;
+ while (mant_bits_left > 0)
+ {
+ mant_bits = min (mant_bits_left, 32);
+
+ if (get_field (ufrom, fmt->byteorder, fmt->totalsize,
+ mant_off, mant_bits) != 0)
+ {
+ /* This is a NaN. */
+ nan = 1;
+ break;
+ }
+
+ mant_off += mant_bits;
+ mant_bits_left -= mant_bits;
+ }
+
+ if (nan)
+ dto = NAN;
+ else
+ dto = INFINITY;
+
+ if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
+ dto = -dto;
+
+ *to = dto;
+
+ return;
+ }