Mercurial > hg > octave-lojdl > gnulib-hg
changeset 6763:16c1945e9422
Make generic.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sat, 29 Apr 2006 16:16:07 +0000 |
parents | 3f978fa80453 |
children | a156a04768bf |
files | lib/ChangeLog lib/gcd.c |
diffstat | 2 files changed, 16 insertions(+), 5 deletions(-) [+] |
line wrap: on
line diff
--- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,8 @@ +2006-04-29 Bruno Haible <bruno@clisp.org> + + * gcd.c: Use WORD_T and GCD instead of unsigned long and gcd. + Suggested by Oskar Liljeblad <oskar@osk.mine.nu>. + 2006-04-25 Paul Eggert <eggert@cs.ucla.edu> * getdate.y (get_date): When adding relative date, start with the
--- a/lib/gcd.c +++ b/lib/gcd.c @@ -1,5 +1,5 @@ /* Arithmetic. - Copyright (C) 2001-2002 Free Software Foundation, Inc. + Copyright (C) 2001-2002, 2006 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2001. This program is free software; you can redistribute it and/or modify @@ -16,14 +16,20 @@ along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ +/* This file can also be used to define gcd functions for other unsigned + types, such as 'unsigned long long' or 'uintmax_t'. */ +#ifndef WORD_T /* Specification. */ -#include "gcd.h" +# include "gcd.h" +# define WORD_T unsigned long +# define GCD gcd +#endif #include <stdlib.h> /* Return the greatest common divisor of a > 0 and b > 0. */ -unsigned long -gcd (unsigned long a, unsigned long b) +WORD_T +GCD (WORD_T a, WORD_T b) { /* Why no division, as in Euclid's algorithm? Because in Euclid's algorithm the division result floor(a/b) or floor(b/a) is very often = 1 or = 2, @@ -33,7 +39,7 @@ bit in a single instruction, and the algorithm uses fewer variables than Euclid's algorithm. */ - unsigned long c = a | b; + WORD_T c = a | b; c = c ^ (c - 1); /* c = largest power of 2 that divides a and b. */