From 78acc472d9719316f22e002a009a998d9ceec29d Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Mon, 12 Apr 2010 22:28:05 -0500 Subject: Rename lib_generic/ to lib/ Now that the other architecture-specific lib directories have been moved out of the top-level directory there's not much reason to have the '_generic' suffix on the common lib directory. Signed-off-by: Peter Tyser --- lib/ldiv.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 lib/ldiv.c (limited to 'lib/ldiv.c') diff --git a/lib/ldiv.c b/lib/ldiv.c new file mode 100644 index 0000000..5d231a2 --- /dev/null +++ b/lib/ldiv.c @@ -0,0 +1,55 @@ +/* Copyright (C) 1992, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C 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. */ + +typedef struct { + long quot; + long rem; +} ldiv_t; +/* Return the `ldiv_t' representation of NUMER over DENOM. */ +ldiv_t +ldiv (long int numer, long int denom) +{ + ldiv_t result; + + result.quot = numer / denom; + result.rem = numer % denom; + + /* The ANSI standard says that |QUOT| <= |NUMER / DENOM|, where + NUMER / DENOM is to be computed in infinite precision. In + other words, we should always truncate the quotient towards + zero, never -infinity. Machine division and remainer may + work either way when one or both of NUMER or DENOM is + negative. If only one is negative and QUOT has been + truncated towards -infinity, REM will have the same sign as + DENOM and the opposite sign of NUMER; if both are negative + and QUOT has been truncated towards -infinity, REM will be + positive (will have the opposite sign of NUMER). These are + considered `wrong'. If both are NUM and DENOM are positive, + RESULT will always be positive. This all boils down to: if + NUMER >= 0, but REM < 0, we got the wrong answer. In that + case, to get the right answer, add 1 to QUOT and subtract + DENOM from REM. */ + + if (numer >= 0 && result.rem < 0) + { + ++result.quot; + result.rem -= denom; + } + + return result; +} -- cgit v1.1