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author | partain <unknown> | 1996-01-08 20:28:12 +0000 |
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committer | partain <unknown> | 1996-01-08 20:28:12 +0000 |
commit | e7d21ee4f8ac907665a7e170c71d59e13a01da09 (patch) | |
tree | 93715bf4e6e4bbe8049e4d8d4d3fbd19158a88d6 /ghc/runtime/gmp/mpz_mdm.c | |
parent | e48474bff05e6cfb506660420f025f694c870d38 (diff) | |
download | haskell-e7d21ee4f8ac907665a7e170c71d59e13a01da09.tar.gz |
[project @ 1996-01-08 20:28:12 by partain]
Initial revision
Diffstat (limited to 'ghc/runtime/gmp/mpz_mdm.c')
-rw-r--r-- | ghc/runtime/gmp/mpz_mdm.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/ghc/runtime/gmp/mpz_mdm.c b/ghc/runtime/gmp/mpz_mdm.c new file mode 100644 index 0000000000..0844643626 --- /dev/null +++ b/ghc/runtime/gmp/mpz_mdm.c @@ -0,0 +1,64 @@ +/* mpz_mdivmod -- Mathematical DIVision and MODulo, i.e. division that rounds + the quotient towards -infinity, and with the remainder non-negative. + +Copyright (C) 1991, 1992 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_mdivmod (MP_INT *quot, MP_INT *rem, + const MP_INT *dividend, const MP_INT *divisor) +#else +mpz_mdivmod (quot, rem, dividend, divisor) + MP_INT *quot; + MP_INT *rem; + const MP_INT *dividend; + const MP_INT *divisor; +#endif +{ + if ((dividend->size ^ divisor->size) >= 0) + { + /* When the dividend and the divisor has same sign, this function + gives same result as mpz_divmod. */ + mpz_divmod (quot, rem, dividend, divisor); + } + else + { + MP_INT temp_divisor; /* N.B.: lives until function returns! */ + + /* We need the original value of the divisor after the quotient and + remainder have been preliminary calculated. We have to copy it to + temporary space if it's the same variable as either QUOT or REM. */ + if (quot == divisor || rem == divisor) + { + MPZ_TMP_INIT (&temp_divisor, ABS (divisor->size)); + mpz_set (&temp_divisor, divisor); + divisor = &temp_divisor; + } + + mpz_divmod (quot, rem, dividend, divisor); + if (rem->size != 0) + { + mpz_sub_ui (quot, quot, 1); + mpz_add (rem, rem, divisor); + } + } +} |