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* build-aux/gendocs.sh (version): * doc/gendocs_template: * doc/gendocs_template_min: * doc/gnulib.texi: * lib/version-etc.c (COPYRIGHT_YEAR): Update copyright dates by hand in templates and the like. * all files: Run 'make update-copyright'.
69 lines
1.7 KiB
C
69 lines
1.7 KiB
C
/*
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* Copyright (C) 2011-2017 Free Software Foundation, Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Written by Eric Blake. */
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#include <config.h>
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#include <strings.h>
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#include "signature.h"
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SIGNATURE_CHECK (ffs, int, (int));
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#include <limits.h>
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#include "macros.h"
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#define NBITS (sizeof (int) * CHAR_BIT)
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static int
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naive (int i)
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{
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unsigned int j;
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for (j = 0; j < NBITS; j++)
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if (i & (1U << j))
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return j + 1;
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return 0;
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}
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int
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main (int argc, char *argv[])
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{
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int x;
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int i;
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for (x = -128; x <= 128; x++)
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ASSERT (ffs (x) == naive (x));
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for (i = 0; i < NBITS; i++)
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{
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ASSERT (ffs (1U << i) == naive (1U << i));
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ASSERT (ffs (1U << i) == i + 1);
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ASSERT (ffs (-1U << i) == i + 1);
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}
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for (i = 0; i < NBITS - 1; i++)
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{
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ASSERT (ffs (3U << i) == i + 1);
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ASSERT (ffs (-3U << i) == i + 1);
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}
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for (i = 0; i < NBITS - 2; i++)
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{
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ASSERT (ffs (5U << i) == i + 1);
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ASSERT (ffs (-5U << i) == i + 1);
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ASSERT (ffs (7U << i) == i + 1);
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ASSERT (ffs (-7U << i) == i + 1);
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}
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return 0;
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}
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