diff options
Diffstat (limited to 'ghc/runtime/gmp/mpz_add_ui.c')
-rw-r--r-- | ghc/runtime/gmp/mpz_add_ui.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/ghc/runtime/gmp/mpz_add_ui.c b/ghc/runtime/gmp/mpz_add_ui.c new file mode 100644 index 0000000000..34f754b28e --- /dev/null +++ b/ghc/runtime/gmp/mpz_add_ui.c @@ -0,0 +1,84 @@ +/* mpz_add_ui -- Add an MP_INT and an unsigned one-word integer. + +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" + +void +#ifdef __STDC__ +mpz_add_ui (MP_INT *sum, const MP_INT *add1, mp_limb add2) +#else +mpz_add_ui (sum, add1, add2) + MP_INT *sum; + const MP_INT *add1; + mp_limb add2; +#endif +{ + mp_srcptr add1p; + mp_ptr sump; + mp_size add1size, sumsize; + mp_size abs_add1size; + + add1size = add1->size; + abs_add1size = ABS (add1size); + + /* If not space for SUM (and possible carry), increase space. */ + sumsize = abs_add1size + 1; + if (sum->alloc < sumsize) + _mpz_realloc (sum, sumsize); + + /* These must be after realloc (ADD1 may be the same as SUM). */ + add1p = add1->d; + sump = sum->d; + + if (add2 == 0) + { + MPN_COPY (sump, add1p, abs_add1size); + sum->size = add1size; + return; + } + if (abs_add1size == 0) + { + sump[0] = add2; + sum->size = 1; + return; + } + + if (add1size >= 0) + { + sumsize = mpn_add (sump, add1p, abs_add1size, &add2, 1); + if (sumsize != 0) + sump[abs_add1size] = 1; + sumsize = sumsize + abs_add1size; + } + else + { + /* The signs are different. Need exact comparision to determine + which operand to subtract from which. */ + if (abs_add1size == 1 && add1p[0] < add2) + sumsize = (abs_add1size + + mpn_sub (sump, &add2, 1, add1p, 1)); + else + sumsize = -(abs_add1size + + mpn_sub (sump, add1p, abs_add1size, &add2, 1)); + } + + sum->size = sumsize; +} |