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Unified Diff: gcc/gmp/mpn/generic/mu_div_q.c

Issue 3050029: [gcc] GCC 4.5.0=>4.5.1 (Closed) Base URL: ssh://git@gitrw.chromium.org:9222/nacl-toolchain.git
Patch Set: Created 10 years, 5 months ago
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Index: gcc/gmp/mpn/generic/mu_div_q.c
diff --git a/gcc/gmp/mpn/generic/mu_div_q.c b/gcc/gmp/mpn/generic/mu_div_q.c
deleted file mode 100644
index 150e8b77cd8ac8afbca99c970a192e44ca4447f9..0000000000000000000000000000000000000000
--- a/gcc/gmp/mpn/generic/mu_div_q.c
+++ /dev/null
@@ -1,157 +0,0 @@
-/* mpn_mu_div_q, mpn_preinv_mu_div_q.
-
- Contributed to the GNU project by Torbjörn Granlund.
-
- THE FUNCTIONS IN THIS FILE ARE INTERNAL WITH A MUTABLE INTERFACE. IT IS
- ONLY SAFE TO REACH THEM THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS
- ALMOST GUARANTEED THAT THEY WILL CHANGE OR DISAPPEAR IN A FUTURE GMP
- RELEASE.
-
-Copyright 2005, 2006, 2007 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 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.
-
-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 Lesser General Public
-License for more details.
-
-You should have received a copy of the GNU Lesser General Public License
-along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
-
-
-/*
- Things to work on:
-
- 1. This is a rudimentary implementation of mpn_mu_div_q. The algorithm is
- probably close to optimal, except when mpn_mu_divappr_q fails.
-
- An alternative which could be considered for much simpler code for the
- complex qn>=dn arm would be to allocate a temporary nn+1 limb buffer, then
- simply call mpn_mu_divappr_q. Such a temporary allocation is
- unfortunately very large.
-
- 2. Instead of falling back to mpn_mu_div_qr when we detect a possible
- mpn_mu_divappr_q rounding problem, we could multiply and compare.
- Unfortunately, since mpn_mu_divappr_q does not return the partial
- remainder, this also doesn't become optimal. A mpn_mu_divappr_qr
- could solve that.
-
- 3. The allocations done here should be made from the scratch area.
-*/
-
-#include <stdlib.h> /* for NULL */
-#include "gmp.h"
-#include "gmp-impl.h"
-
-
-mp_limb_t
-mpn_mu_div_q (mp_ptr qp,
- mp_ptr np, mp_size_t nn,
- mp_srcptr dp, mp_size_t dn,
- mp_ptr scratch)
-{
- mp_ptr tp, rp, ip, this_ip;
- mp_size_t qn, in, this_in;
- mp_limb_t cy;
- TMP_DECL;
-
- TMP_MARK;
-
- qn = nn - dn;
-
- tp = TMP_BALLOC_LIMBS (qn + 1);
-
- if (qn >= dn) /* nn >= 2*dn + 1 */
- {
- /* Find max inverse size needed by the two preinv calls. */
- if (dn != qn)
- {
- mp_size_t in1, in2;
-
- in1 = mpn_mu_div_qr_choose_in (qn - dn, dn, 0);
- in2 = mpn_mu_divappr_q_choose_in (dn + 1, dn, 0);
- in = MAX (in1, in2);
- }
- else
- {
- in = mpn_mu_divappr_q_choose_in (dn + 1, dn, 0);
- }
-
- ip = TMP_BALLOC_LIMBS (in + 1);
-
- if (dn == in)
- {
- MPN_COPY (scratch + 1, dp, in);
- scratch[0] = 1;
- mpn_invert (ip, scratch, in + 1, NULL);
- MPN_COPY_INCR (ip, ip + 1, in);
- }
- else
- {
- cy = mpn_add_1 (scratch, dp + dn - (in + 1), in + 1, 1);
- if (UNLIKELY (cy != 0))
- MPN_ZERO (ip, in);
- else
- {
- mpn_invert (ip, scratch, in + 1, NULL);
- MPN_COPY_INCR (ip, ip + 1, in);
- }
- }
-
- /* |_______________________| dividend
- |________| divisor */
- rp = TMP_BALLOC_LIMBS (2 * dn + 1);
- if (dn != qn) /* FIXME: perhaps mpn_mu_div_qr should DTRT */
- {
- this_in = mpn_mu_div_qr_choose_in (qn - dn, dn, 0);
- this_ip = ip + in - this_in;
- mpn_preinv_mu_div_qr (tp + dn + 1, rp + dn + 1, np + dn, qn, dp, dn,
- this_ip, this_in, scratch);
- }
- else
- MPN_COPY (rp + dn + 1, np + dn, dn);
-
- MPN_COPY (rp + 1, np, dn);
- rp[0] = 0;
- this_in = mpn_mu_divappr_q_choose_in (dn + 1, dn, 0);
- this_ip = ip + in - this_in;
- mpn_preinv_mu_divappr_q (tp, rp, 2*dn + 1, dp, dn, this_ip, this_in, scratch);
-
- /* The max error of mpn_mu_divappr_q is +4. If the low quotient limb is
- greater than the max error, we cannot trust the quotient. */
- if (tp[0] > 4)
- {
- MPN_COPY (qp, tp + 1, qn);
- }
- else
- {
- /* Fall back to plain mpn_mu_div_qr. */
- mpn_mu_div_qr (qp, rp, np, nn, dp, dn, scratch);
- }
- }
- else
- {
- /* |_______________________| dividend
- |________________| divisor */
- mpn_mu_divappr_q (tp, np + nn - (2*qn + 2), 2*qn + 2, dp + dn - (qn + 1), qn + 1, scratch);
-
- if (tp[0] > 4)
- {
- MPN_COPY (qp, tp + 1, qn);
- }
- else
- {
- rp = TMP_BALLOC_LIMBS (dn);
- mpn_mu_div_qr (qp, rp, np, nn, dp, dn, scratch);
- }
- }
-
- TMP_FREE;
- return 0;
-}
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