diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c b/sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c index 5149ba10bf..e46fde74fc 100644 --- a/sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c +++ b/sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c @@ -36,6 +36,7 @@ __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size, union ibm_extended_long_double u; unsigned long long hi, lo; int ediff; + u.ld = value; *is_neg = u.d[0].ieee.negative; @@ -43,27 +44,36 @@ __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size, lo = ((long long) u.d[1].ieee.mantissa0 << 32) | u.d[1].ieee.mantissa1; hi = ((long long) u.d[0].ieee.mantissa0 << 32) | u.d[0].ieee.mantissa1; - /* If the lower double is not a denomal or zero then set the hidden + + /* If the lower double is not a denormal or zero then set the hidden 53rd bit. */ - if (u.d[1].ieee.exponent > 0) - { - lo |= 1LL << 52; + if (u.d[1].ieee.exponent != 0) + lo |= 1ULL << 52; + else + lo = lo << 1; - /* The lower double is normalized separately from the upper. We may - need to adjust the lower manitissa to reflect this. */ - ediff = u.d[0].ieee.exponent - u.d[1].ieee.exponent; - if (ediff > 53) - lo = lo >> (ediff-53); + /* The lower double is normalized separately from the upper. We may + need to adjust the lower manitissa to reflect this. */ + ediff = u.d[0].ieee.exponent - u.d[1].ieee.exponent - 53; + if (ediff > 0) + { + if (ediff < 64) + lo = lo >> ediff; + else + lo = 0; } + else if (ediff < 0) + lo = lo << -ediff; + /* The high double may be rounded and the low double reflects the difference between the long double and the rounded high double value. This is indicated by a differnce between the signs of the high and low doubles. */ - if ((u.d[0].ieee.negative != u.d[1].ieee.negative) - && ((u.d[1].ieee.exponent != 0) && (lo != 0L))) + if (u.d[0].ieee.negative != u.d[1].ieee.negative + && lo != 0) { lo = (1ULL << 53) - lo; - if (hi == 0LL) + if (hi == 0) { /* we have a borrow from the hidden bit, so shift left 1. */ hi = 0x0ffffffffffffeLL | (lo >> 51); |