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76 lines
2.0 KiB
C
76 lines
2.0 KiB
C
/* Round argument to nearest integral value according to current rounding
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direction.
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Copyright (C) 1997-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<http://www.gnu.org/licenses/>. */
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#include <math.h>
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#include <math_private.h>
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#include "mathimpl.h"
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long long int
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__llrint (double x)
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{
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int32_t e;
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u_int32_t h, l, s;
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long long int result;
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x = __m81_u(__rint) (x);
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/* We could use __fixxfdi from libgcc, but here we can take advantage of
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the known floating point format. */
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EXTRACT_WORDS (h, l, x);
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e = ((h >> 20) & 0x7ff) - 0x3ff;
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if (e < 0)
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return 0;
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s = h;
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h &= 0xfffff;
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h |= 0x100000;
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if (e < 63)
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{
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if (e > 52)
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{
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h <<= e - 52;
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h |= l >> (84 - e);
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l <<= e - 52;
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result = ((long long int) h << 32) | l;
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}
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else if (e > 20)
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{
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l >>= 52 - e;
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l |= h << (e - 20);
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h >>= 52 - e;
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result = ((long long int) h << 32) | l;
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}
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else
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result = h >> (20 - e);
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if (s & 0x80000000)
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result = -result;
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}
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else
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/* The number is too large or not finite. The standard leaves it
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undefined what to return when the number is too large to fit in a
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`long long int'. */
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result = -1LL;
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return result;
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}
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weak_alias (__llrint, llrint)
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