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* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
79 lines
2.6 KiB
C
79 lines
2.6 KiB
C
/* Return the least floating-point number greater than X.
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Copyright (C) 2016-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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 <math_ldbl_opt.h>
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/* Return the least floating-point number greater than X. */
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long double
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__nextupl (long double x)
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{
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int64_t hx, ihx, lx;
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double xhi, xlo, yhi;
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ldbl_unpack (x, &xhi, &xlo);
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EXTRACT_WORDS64 (hx, xhi);
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EXTRACT_WORDS64 (lx, xlo);
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ihx = hx & 0x7fffffffffffffffLL;
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if (ihx > 0x7ff0000000000000LL) /* x is nan. */
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return x + x; /* Signal the nan. */
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if (ihx == 0)
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return LDBL_TRUE_MIN;
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long double u;
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if ((hx == 0x7fefffffffffffffLL) && (lx == 0x7c8ffffffffffffeLL))
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return INFINITY;
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if ((uint64_t) hx >= 0xfff0000000000000ULL)
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{
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u = -0x1.fffffffffffff7ffffffffffff8p+1023L;
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return u;
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}
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if (ihx <= 0x0360000000000000LL)
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{ /* x <= LDBL_MIN. */
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x += LDBL_TRUE_MIN;
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if (x == 0.0L) /* Handle negative LDBL_TRUE_MIN case. */
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x = -0.0L;
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return x;
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}
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/* If the high double is an exact power of two and the low
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double is the opposite sign, then 1ulp is one less than
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what we might determine from the high double. Similarly
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if X is an exact power of two, and negative, because
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making it a little larger will result in the exponent
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decreasing by one and normalisation of the mantissa. */
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if ((hx & 0x000fffffffffffffLL) == 0
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&& ((lx != 0 && lx != 0x8000000000000000LL && (hx ^ lx) < 0)
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|| ((lx == 0 || lx == 0x8000000000000000LL) && hx < 0)))
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ihx -= 1LL << 52;
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if (ihx < (106LL << 52))
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{ /* ulp will denormal. */
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INSERT_WORDS64 (yhi, ihx & (0x7ffLL << 52));
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u = yhi * 0x1p-105;
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}
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else
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{
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INSERT_WORDS64 (yhi, (ihx & (0x7ffLL << 52)) - (105LL << 52));
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u = yhi;
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}
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return x + u;
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}
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weak_alias (__nextupl, nextupl)
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