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71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
/* Round float to integer away from zero.
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Copyright (C) 1997, 2011 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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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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static const float huge = 1.0e30;
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float
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__roundf (float x)
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{
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int32_t i0, j0;
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GET_FLOAT_WORD (i0, x);
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j0 = ((i0 >> 23) & 0xff) - 0x7f;
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if (j0 < 23)
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{
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if (j0 < 0)
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{
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math_force_eval (huge + x);
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i0 &= 0x80000000;
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if (j0 == -1)
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i0 |= 0x3f800000;
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}
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else
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{
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u_int32_t i = 0x007fffff >> j0;
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if ((i0 & i) == 0)
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/* X is integral. */
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return x;
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math_force_eval (huge + x);
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/* Raise inexact if x != 0. */
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i0 += 0x00400000 >> j0;
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i0 &= ~i;
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}
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}
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else
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{
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if (j0 == 0x80)
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/* Inf or NaN. */
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return x + x;
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else
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return x;
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}
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SET_FLOAT_WORD (x, i0);
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return x;
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}
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weak_alias (__roundf, roundf)
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