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Diffstat (limited to 'ghc/runtime/gmp/mpz_mul.c')
-rw-r--r-- | ghc/runtime/gmp/mpz_mul.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/ghc/runtime/gmp/mpz_mul.c b/ghc/runtime/gmp/mpz_mul.c new file mode 100644 index 0000000000..7bb2b90859 --- /dev/null +++ b/ghc/runtime/gmp/mpz_mul.c @@ -0,0 +1,114 @@ +/* mpz_mul -- Multiply two integers. + +Copyright (C) 1991 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 General Public License as published by +the Free Software Foundation; either version 2, 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 General Public License for more details. + +You should have received a copy of the GNU General Public License +along with the GNU MP Library; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "gmp.h" +#include "gmp-impl.h" + +#ifndef BERKELEY_MP +void +#ifdef __STDC__ +mpz_mul (MP_INT *w, const MP_INT *u, const MP_INT *v) +#else +mpz_mul (w, u, v) + MP_INT *w; + const MP_INT *u; + const MP_INT *v; +#endif +#else /* BERKELEY_MP */ +void +#ifdef __STDC__ +mult (const MP_INT *u, const MP_INT *v, MP_INT *w) +#else +mult (u, v, w) + const MP_INT *u; + const MP_INT *v; + MP_INT *w; +#endif +#endif /* BERKELEY_MP */ +{ + mp_size usize = u->size; + mp_size vsize = v->size; + mp_size wsize; + mp_size sign_product; + mp_ptr up, vp; + mp_ptr wp; + mp_ptr free_me = NULL; + size_t free_me_size; + + sign_product = usize ^ vsize; + usize = ABS (usize); + vsize = ABS (vsize); + + if (usize < vsize) + { + /* Swap U and V. */ + {const MP_INT *t = u; u = v; v = t;} + {mp_size t = usize; usize = vsize; vsize = t;} + } + + up = u->d; + vp = v->d; + wp = w->d; + + /* Ensure W has space enough to store the result. */ + wsize = usize + vsize; + if (w->alloc < wsize) + { + if (wp == up || wp == vp) + { + free_me = wp; + free_me_size = w->alloc; + } + else + (*_mp_free_func) (wp, w->alloc * BYTES_PER_MP_LIMB); + + w->alloc = wsize; + wp = (mp_ptr) (*_mp_allocate_func) (wsize * BYTES_PER_MP_LIMB); + w->d = wp; + } + else + { + /* Make U and V not overlap with W. */ + if (wp == up) + { + /* W and U are identical. Allocate temporary space for U. */ + up = (mp_ptr) alloca (usize * BYTES_PER_MP_LIMB); + /* Is V identical too? Keep it identical with U. */ + if (wp == vp) + vp = up; + /* Copy to the temporary space. */ + MPN_COPY (up, wp, usize); + } + else if (wp == vp) + { + /* W and V are identical. Allocate temporary space for V. */ + vp = (mp_ptr) alloca (vsize * BYTES_PER_MP_LIMB); + /* Copy to the temporary space. */ + MPN_COPY (vp, wp, vsize); + } + } + + wsize = mpn_mul (wp, up, usize, vp, vsize); + w->size = sign_product < 0 ? -wsize : wsize; + if (free_me != NULL) + (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB); + + alloca (0); +} |