diff options
Diffstat (limited to 'rts/gmp/mpn/generic/mul_basecase.c')
-rw-r--r-- | rts/gmp/mpn/generic/mul_basecase.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/rts/gmp/mpn/generic/mul_basecase.c b/rts/gmp/mpn/generic/mul_basecase.c new file mode 100644 index 0000000000..00c06aa5c4 --- /dev/null +++ b/rts/gmp/mpn/generic/mul_basecase.c @@ -0,0 +1,87 @@ +/* mpn_mul_basecase -- Internal routine to multiply two natural numbers + of length m and n. + + THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE. IT IS ONLY + SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES. + + +Copyright (C) 1991, 1992, 1993, 1994, 1996, 1997, 2000 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" + +/* Handle simple cases with traditional multiplication. + + This is the most critical code of multiplication. 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. */ + +void +#if __STDC__ +mpn_mul_basecase (mp_ptr prodp, + mp_srcptr up, mp_size_t usize, + mp_srcptr vp, mp_size_t vsize) +#else +mpn_mul_basecase (prodp, up, usize, vp, vsize) + mp_ptr prodp; + mp_srcptr up; + mp_size_t usize; + mp_srcptr vp; + mp_size_t vsize; +#endif +{ + /* We first multiply by the low order one or two limbs, as the result can + be stored, not added, to PROD. We also avoid a loop for zeroing this + way. */ +#if HAVE_NATIVE_mpn_mul_2 + if (vsize >= 2) + { + prodp[usize + 1] = mpn_mul_2 (prodp, up, usize, vp[0], vp[1]); + prodp += 2, vp += 2, vsize -= 2; + } + else + { + prodp[usize] = mpn_mul_1 (prodp, up, usize, vp[0]); + return; + } +#else + prodp[usize] = mpn_mul_1 (prodp, up, usize, vp[0]); + prodp += 1, vp += 1, vsize -= 1; +#endif + +#if HAVE_NATIVE_mpn_addmul_2 + while (vsize >= 2) + { + prodp[usize + 1] = mpn_addmul_2 (prodp, up, usize, vp[0], vp[1]); + prodp += 2, vp += 2, vsize -= 2; + } + if (vsize != 0) + prodp[usize] = mpn_addmul_1 (prodp, up, usize, vp[0]); +#else + /* For each iteration in the loop, multiply U with one limb from V, and + add the result to PROD. */ + while (vsize != 0) + { + prodp[usize] = mpn_addmul_1 (prodp, up, usize, vp[0]); + prodp += 1, vp += 1, vsize -= 1; + } +#endif +} |