diff options
| author | zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4> | 2017-01-24 10:34:36 +0000 |
|---|---|---|
| committer | zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4> | 2017-01-24 10:34:36 +0000 |
| commit | 57f4a88c504d9b8f82ffddd34f8c8b2484d55710 (patch) | |
| tree | 03e7b5ed9b3785b528c96af22d7f2de73432485e /src/invsqrt_limb.h | |
| parent | 86fa25560949294c84130ac07a883378f36a1aae (diff) | |
| download | mpfr-57f4a88c504d9b8f82ffddd34f8c8b2484d55710.tar.gz | |
[src/invsqrt_limb.h] changed slightly definition of d10 and d37 (does not
change final error analysis)
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@11224 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'src/invsqrt_limb.h')
| -rw-r--r-- | src/invsqrt_limb.h | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/src/invsqrt_limb.h b/src/invsqrt_limb.h index dffda944e..b830172f0 100644 --- a/src/invsqrt_limb.h +++ b/src/invsqrt_limb.h @@ -26,11 +26,11 @@ http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., /* for now, we only provide __gmpfr_invert_limb for 64-bit limb */ #if GMP_NUMB_BITS == 64 -/* For 256 <= d10 <= 1024, T[d10-256] = min(2^11-1,floor(sqrt(2^30/d10))). +/* For 257 <= d10 <= 1024, T[d10-257] = floor(sqrt(2^30/d10)). Sage code: - T = [min(2^11-1,floor(sqrt(2^30/d10))) for d10 in [256..1024]] */ -static const mp_limb_t T[] = - { 2047, 2044, 2040, 2036, 2032, 2028, 2024, 2020, 2016, 2012, 2009, 2005, + T = [floor(sqrt(2^30/d10)) for d10 in [257..1024]] */ +static const mp_limb_t T[768] = + { 2044, 2040, 2036, 2032, 2028, 2024, 2020, 2016, 2012, 2009, 2005, 2001, 1997, 1994, 1990, 1986, 1983, 1979, 1975, 1972, 1968, 1965, 1961, 1958, 1954, 1951, 1947, 1944, 1941, 1937, 1934, 1930, 1927, 1924, 1920, 1917, 1914, 1911, 1907, 1904, 1901, 1898, 1895, 1891, 1888, 1885, 1882, @@ -97,8 +97,8 @@ static const mp_limb_t T[] = 1024 }; /* table of v0^3 */ -static const mp_limb_t T3[] = - { 8577357823, 8539701184, 8489664000, 8439822656, 8390176768, 8340725952, +static const mp_limb_t T3[768] = + { 8539701184, 8489664000, 8439822656, 8390176768, 8340725952, 8291469824, 8242408000, 8193540096, 8144865728, 8108486729, 8060150125, 8012006001, 7964053973, 7928215784, 7880599000, 7833173256, 7797729087, 7750636739, 7703734375, 7668682048, 7622111232, 7587307125, 7541066681, @@ -246,10 +246,10 @@ static const mp_limb_t T3[] = do { \ mp_limb_t _d, _i, _v0, _e0, _d37, _v1, _e1, _h, _v2, _e2; \ _d = (d); \ - _i = ((_d - 1) >> 54) - 255; \ + _i = (_d >> 54) - 256; \ /* i = d10 - 256 */ \ _v0 = T[_i]; \ - _d37 = 1 + ((_d - 1) >> 27); \ + _d37 = 1 + (_d >> 27); \ _e0 = T3[_i] * _d37; \ /* the value (_v0 << 57) - _e0 is less than 2^61 */ \ _v1 = (_v0 << 11) + (((_v0 << 57) - _e0) >> 47); \ |