diff options
Diffstat (limited to 'extract-dbl.c')
| -rw-r--r-- | extract-dbl.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/extract-dbl.c b/extract-dbl.c index d86871a94..18a574db5 100644 --- a/extract-dbl.c +++ b/extract-dbl.c @@ -67,16 +67,40 @@ __gmp_extract_double (rp, d) { union ieee_double_extract x; x.d = d; - exp = x.s.exp; - sc = (unsigned) (exp + 2) % BITS_PER_MP_LIMB; #if BITS_PER_MP_LIMB == 64 manl = (((mp_limb_t) 1 << 63) | ((mp_limb_t) x.s.manh << 43) | ((mp_limb_t) x.s.manl << 11)); + if (exp == 0) + { + /* Denormalized number. Don't try to be clever about this, + since it is not an important case to make fast. */ + exp = 1; + do + { + manl = manl << 1; + exp--; + } + while ((mp_limb_signed_t) manl >= 0); + } #else manh = ((mp_limb_t) 1 << 31) | (x.s.manh << 11) | (x.s.manl >> 21); manl = x.s.manl << 11; + if (exp == 0) + { + /* Denormalized number. Don't try to be clever about this, + since it is not an important case to make fast. */ + exp = 1; + do + { + manh = (manh << 1) | (manl >> 31); + manl = manl << 1; + exp--; + } + while ((mp_limb_signed_t) manh >= 0); + } #endif + exp -= 1022; /* Remove IEEE bias. */ } #else { @@ -112,8 +136,6 @@ __gmp_extract_double (rp, d) } } - sc = (unsigned) exp % BITS_PER_MP_LIMB; - d *= MP_BASE_AS_DOUBLE; #if BITS_PER_MP_LIMB == 64 manl = d; @@ -121,12 +143,13 @@ __gmp_extract_double (rp, d) manh = d; manl = (d - manh) * MP_BASE_AS_DOUBLE; #endif - - exp += 1022; } #endif - exp = (unsigned) (exp + 1) / BITS_PER_MP_LIMB - 1024 / BITS_PER_MP_LIMB + 1; + sc = (unsigned) exp % BITS_PER_MP_LIMB; + + /* We add something here to get rounding right. */ + exp = (exp + 2048) / BITS_PER_MP_LIMB - 2048 / BITS_PER_MP_LIMB + 1; #if BITS_PER_MP_LIMB == 64 if (sc != 0) |