aboutsummaryrefslogtreecommitdiff
path: root/vendor/gmp-6.3.0/mpz/prodlimbs.c
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/gmp-6.3.0/mpz/prodlimbs.c')
-rw-r--r--vendor/gmp-6.3.0/mpz/prodlimbs.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mpz/prodlimbs.c b/vendor/gmp-6.3.0/mpz/prodlimbs.c
new file mode 100644
index 0000000..23f06a1
--- /dev/null
+++ b/vendor/gmp-6.3.0/mpz/prodlimbs.c
@@ -0,0 +1,108 @@
+/* mpz_prodlimbs(RESULT, V, LEN) -- Set RESULT to V[0]*V[1]*...*V[LEN-1].
+
+Contributed to the GNU project by Marco Bodrato.
+
+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 GNU MP RELEASE.
+
+Copyright 2010-2012 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-impl.h"
+
+/*********************************************************/
+/* Section list-prod: product of a list -> mpz_t */
+/*********************************************************/
+
+/* FIXME: should be tuned */
+#ifndef RECURSIVE_PROD_THRESHOLD
+#define RECURSIVE_PROD_THRESHOLD (MUL_TOOM22_THRESHOLD)
+#endif
+
+/* Computes the product of the j>1 limbs pointed by factors, puts the
+ * result in x. It assumes that all limbs are non-zero. Above
+ * Karatsuba's threshold it uses a binary splitting strategy, to gain
+ * speed by the asymptotically fast multiplication algorithms.
+ *
+ * The list in {factors, j} is overwritten.
+ * Returns the size of the result
+ */
+
+mp_size_t
+mpz_prodlimbs (mpz_ptr x, mp_ptr factors, mp_size_t j)
+{
+ mp_limb_t cy;
+ mp_size_t size, i;
+ mp_ptr prod;
+
+ ASSERT (j > 1);
+ ASSERT (RECURSIVE_PROD_THRESHOLD > 3);
+
+ if (BELOW_THRESHOLD (j, RECURSIVE_PROD_THRESHOLD)) {
+ j--;
+ size = 1;
+
+ for (i = 1; i < j; i++)
+ {
+ cy = mpn_mul_1 (factors, factors, size, factors[i]);
+ factors[size] = cy;
+ size += cy != 0;
+ };
+
+ prod = MPZ_NEWALLOC (x, size + 1);
+
+ cy = mpn_mul_1 (prod, factors, size, factors[i]);
+ prod[size] = cy;
+ return SIZ (x) = size + (cy != 0);
+ } else {
+ mpz_t x1, x2;
+ TMP_DECL;
+
+ i = j >> 1;
+ j -= i;
+ TMP_MARK;
+
+ MPZ_TMP_INIT (x2, j);
+
+ PTR (x1) = factors + i;
+ ALLOC (x1) = j;
+ j = mpz_prodlimbs (x2, factors + i, j);
+ i = mpz_prodlimbs (x1, factors, i);
+ size = i + j;
+ prod = MPZ_NEWALLOC (x, size);
+ if (i >= j)
+ cy = mpn_mul (prod, PTR(x1), i, PTR(x2), j);
+ else
+ cy = mpn_mul (prod, PTR(x2), j, PTR(x1), i);
+ TMP_FREE;
+
+ return SIZ (x) = size - (cy == 0);
+ }
+}