diff options
Diffstat (limited to 'stdlib/mul.c')
| -rw-r--r-- | stdlib/mul.c | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/stdlib/mul.c b/stdlib/mul.c deleted file mode 100644 index fe0cbf3d7f..0000000000 --- a/stdlib/mul.c +++ /dev/null @@ -1,152 +0,0 @@ -/* mpn_mul -- Multiply two natural numbers. - -Copyright (C) 1991, 1993, 1994, 1996 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 2.1 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; see the file COPYING.LIB. If not, write to -the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, -MA 02111-1307, USA. */ - -#include <gmp.h> -#include "gmp-impl.h" - -/* Multiply the natural numbers u (pointed to by UP, with USIZE limbs) - and v (pointed to by VP, with VSIZE limbs), and store the result at - PRODP. USIZE + VSIZE limbs are always stored, but if the input - operands are normalized. Return the most significant limb of the - result. - - NOTE: The space pointed to by PRODP is overwritten before finished - with U and V, so overlap is an error. - - Argument constraints: - 1. USIZE >= VSIZE. - 2. PRODP != UP and PRODP != VP, i.e. the destination - must be distinct from the multiplier and the multiplicand. */ - -/* If KARATSUBA_THRESHOLD is not already defined, define it to a - value which is good on most machines. */ -#ifndef KARATSUBA_THRESHOLD -#define KARATSUBA_THRESHOLD 32 -#endif - -mp_limb_t -#if __STDC__ -mpn_mul (mp_ptr prodp, - mp_srcptr up, mp_size_t usize, - mp_srcptr vp, mp_size_t vsize) -#else -mpn_mul (prodp, up, usize, vp, vsize) - mp_ptr prodp; - mp_srcptr up; - mp_size_t usize; - mp_srcptr vp; - mp_size_t vsize; -#endif -{ - mp_ptr prod_endp = prodp + usize + vsize - 1; - mp_limb_t cy; - mp_ptr tspace; - TMP_DECL (marker); - - if (vsize < KARATSUBA_THRESHOLD) - { - /* Handle simple cases with traditional multiplication. - - This is the most critical code of the entire function. All - multiplies rely on this, both small and huge. Small ones arrive - here immediately. Huge ones arrive here as this is the base case - for Karatsuba's recursive algorithm below. */ - mp_size_t i; - mp_limb_t cy_limb; - mp_limb_t v_limb; - - if (vsize == 0) - return 0; - - /* Multiply by the first limb in V separately, as the result can be - stored (not added) to PROD. We also avoid a loop for zeroing. */ - v_limb = vp[0]; - if (v_limb <= 1) - { - if (v_limb == 1) - MPN_COPY (prodp, up, usize); - else - MPN_ZERO (prodp, usize); - cy_limb = 0; - } - else - cy_limb = mpn_mul_1 (prodp, up, usize, v_limb); - - prodp[usize] = cy_limb; - prodp++; - - /* For each iteration in the outer loop, multiply one limb from - U with one limb from V, and add it to PROD. */ - for (i = 1; i < vsize; i++) - { - v_limb = vp[i]; - if (v_limb <= 1) - { - cy_limb = 0; - if (v_limb == 1) - cy_limb = mpn_add_n (prodp, prodp, up, usize); - } - else - cy_limb = mpn_addmul_1 (prodp, up, usize, v_limb); - - prodp[usize] = cy_limb; - prodp++; - } - return cy_limb; - } - - TMP_MARK (marker); - - tspace = (mp_ptr) TMP_ALLOC (2 * vsize * BYTES_PER_MP_LIMB); - MPN_MUL_N_RECURSE (prodp, up, vp, vsize, tspace); - - prodp += vsize; - up += vsize; - usize -= vsize; - if (usize >= vsize) - { - mp_ptr tp = (mp_ptr) TMP_ALLOC (2 * vsize * BYTES_PER_MP_LIMB); - do - { - MPN_MUL_N_RECURSE (tp, up, vp, vsize, tspace); - cy = mpn_add_n (prodp, prodp, tp, vsize); - mpn_add_1 (prodp + vsize, tp + vsize, vsize, cy); - prodp += vsize; - up += vsize; - usize -= vsize; - } - while (usize >= vsize); - } - - /* True: usize < vsize. */ - - /* Make life simple: Recurse. */ - - if (usize != 0) - { - mpn_mul (tspace, vp, vsize, up, usize); - cy = mpn_add_n (prodp, prodp, tspace, vsize); - mpn_add_1 (prodp + vsize, tspace + vsize, usize, cy); - } - - TMP_FREE (marker); - return *prod_endp; -} |