summaryrefslogtreecommitdiff
path: root/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/redc_n.c
diff options
context:
space:
mode:
Diffstat (limited to 'Build/source/libs/gmp/gmp-6.0.0/mpn/generic/redc_n.c')
-rw-r--r--Build/source/libs/gmp/gmp-6.0.0/mpn/generic/redc_n.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/redc_n.c b/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/redc_n.c
new file mode 100644
index 00000000000..c3d0cfe7fa3
--- /dev/null
+++ b/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/redc_n.c
@@ -0,0 +1,81 @@
+/* mpn_redc_n. Set rp[] <- up[]/R^n mod mp[]. Clobber up[].
+ mp[] is n limbs; up[] is 2n limbs, the inverse ip[] is n limbs.
+
+ THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE. IT IS ONLY
+ SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
+
+Copyright 2009, 2012 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"
+
+/*
+ TODO
+
+ * We assume mpn_mulmod_bnm1 is always faster than plain mpn_mul_n (or a
+ future mpn_mulhi) for the range we will be called. Follow up that
+ assumption.
+
+ * Decrease scratch usage.
+
+ * Consider removing the residue canonicalisation.
+*/
+
+void
+mpn_redc_n (mp_ptr rp, mp_ptr up, mp_srcptr mp, mp_size_t n, mp_srcptr ip)
+{
+ mp_ptr xp, yp, scratch;
+ mp_limb_t cy;
+ mp_size_t rn;
+ TMP_DECL;
+ TMP_MARK;
+
+ ASSERT (n > 8);
+
+ rn = mpn_mulmod_bnm1_next_size (n);
+
+ scratch = TMP_ALLOC_LIMBS (n + rn + mpn_mulmod_bnm1_itch (rn, n, n));
+
+ xp = scratch;
+ mpn_mullo_n (xp, up, ip, n);
+
+ yp = scratch + n;
+ mpn_mulmod_bnm1 (yp, rn, xp, n, mp, n, scratch + n + rn);
+
+ ASSERT_ALWAYS (2 * n > rn); /* could handle this */
+
+ cy = mpn_sub_n (yp + rn, yp, up, 2*n - rn); /* undo wrap around */
+ MPN_DECR_U (yp + 2*n - rn, rn, cy);
+
+ cy = mpn_sub_n (rp, up + n, yp + n, n);
+ if (cy != 0)
+ mpn_add_n (rp, rp, mp, n);
+
+ TMP_FREE;
+}