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Diffstat (limited to 'gmp/mpn/generic/sbpi1_divappr_q.c')
| -rw-r--r-- | gmp/mpn/generic/sbpi1_divappr_q.c | 199 |
1 files changed, 0 insertions, 199 deletions
diff --git a/gmp/mpn/generic/sbpi1_divappr_q.c b/gmp/mpn/generic/sbpi1_divappr_q.c deleted file mode 100644 index 3e7cf91ba6..0000000000 --- a/gmp/mpn/generic/sbpi1_divappr_q.c +++ /dev/null @@ -1,199 +0,0 @@ -/* mpn_sbpi1_divappr_q -- Schoolbook division using the Möller-Granlund 3/2 - division algorithm, returning approximate quotient. The quotient returned - is either correct, or one too large. - - Contributed to the GNU project by Torbjorn Granlund. - - THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE. IT IS ONLY - SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST - GUARANTEED THAT IT WILL CHANGE OR DISAPPEAR IN A FUTURE GMP RELEASE. - -Copyright 2007, 2009 Free Software Foundation, Inc. - -This file is part of the GNU MP Library. - -The GNU MP Library is free software; you can redistribute it and/or modify -it under the terms of either: - - * the GNU Lesser General Public License as published by the Free - Software Foundation; either version 3 of the License, or (at your - option) any later version. - -or - - * the GNU General Public License as published by the Free Software - Foundation; either version 2 of the License, or (at your option) any - later version. - -or both in parallel, as here. - -The GNU MP Library is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -for more details. - -You should have received copies of the GNU General Public License and the -GNU Lesser General Public License along with the GNU MP Library. If not, -see https://www.gnu.org/licenses/. */ - - -#include "gmp.h" -#include "gmp-impl.h" -#include "longlong.h" - -mp_limb_t -mpn_sbpi1_divappr_q (mp_ptr qp, - mp_ptr np, mp_size_t nn, - mp_srcptr dp, mp_size_t dn, - mp_limb_t dinv) -{ - mp_limb_t qh; - mp_size_t qn, i; - mp_limb_t n1, n0; - mp_limb_t d1, d0; - mp_limb_t cy, cy1; - mp_limb_t q; - mp_limb_t flag; - - ASSERT (dn > 2); - ASSERT (nn >= dn); - ASSERT ((dp[dn-1] & GMP_NUMB_HIGHBIT) != 0); - - np += nn; - - qn = nn - dn; - if (qn + 1 < dn) - { - dp += dn - (qn + 1); - dn = qn + 1; - } - - qh = mpn_cmp (np - dn, dp, dn) >= 0; - if (qh != 0) - mpn_sub_n (np - dn, np - dn, dp, dn); - - qp += qn; - - dn -= 2; /* offset dn by 2 for main division loops, - saving two iterations in mpn_submul_1. */ - d1 = dp[dn + 1]; - d0 = dp[dn + 0]; - - np -= 2; - - n1 = np[1]; - - for (i = qn - (dn + 2); i >= 0; i--) - { - np--; - if (UNLIKELY (n1 == d1) && np[1] == d0) - { - q = GMP_NUMB_MASK; - mpn_submul_1 (np - dn, dp, dn + 2, q); - n1 = np[1]; /* update n1, last loop's value will now be invalid */ - } - else - { - udiv_qr_3by2 (q, n1, n0, n1, np[1], np[0], d1, d0, dinv); - - cy = mpn_submul_1 (np - dn, dp, dn, q); - - cy1 = n0 < cy; - n0 = (n0 - cy) & GMP_NUMB_MASK; - cy = n1 < cy1; - n1 -= cy1; - np[0] = n0; - - if (UNLIKELY (cy != 0)) - { - n1 += d1 + mpn_add_n (np - dn, np - dn, dp, dn + 1); - q--; - } - } - - *--qp = q; - } - - flag = ~CNST_LIMB(0); - - if (dn >= 0) - { - for (i = dn; i > 0; i--) - { - np--; - if (UNLIKELY (n1 >= (d1 & flag))) - { - q = GMP_NUMB_MASK; - cy = mpn_submul_1 (np - dn, dp, dn + 2, q); - - if (UNLIKELY (n1 != cy)) - { - if (n1 < (cy & flag)) - { - q--; - mpn_add_n (np - dn, np - dn, dp, dn + 2); - } - else - flag = 0; - } - n1 = np[1]; - } - else - { - udiv_qr_3by2 (q, n1, n0, n1, np[1], np[0], d1, d0, dinv); - - cy = mpn_submul_1 (np - dn, dp, dn, q); - - cy1 = n0 < cy; - n0 = (n0 - cy) & GMP_NUMB_MASK; - cy = n1 < cy1; - n1 -= cy1; - np[0] = n0; - - if (UNLIKELY (cy != 0)) - { - n1 += d1 + mpn_add_n (np - dn, np - dn, dp, dn + 1); - q--; - } - } - - *--qp = q; - - /* Truncate operands. */ - dn--; - dp++; - } - - np--; - if (UNLIKELY (n1 >= (d1 & flag))) - { - q = GMP_NUMB_MASK; - cy = mpn_submul_1 (np, dp, 2, q); - - if (UNLIKELY (n1 != cy)) - { - if (n1 < (cy & flag)) - { - q--; - add_ssaaaa (np[1], np[0], np[1], np[0], dp[1], dp[0]); - } - else - flag = 0; - } - n1 = np[1]; - } - else - { - udiv_qr_3by2 (q, n1, n0, n1, np[1], np[0], d1, d0, dinv); - - np[1] = n1; - np[0] = n0; - } - - *--qp = q; - } - - ASSERT_ALWAYS (np[1] == n1); - - return qh; -} |