58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
/* Multiply by integral power of radix.
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Copyright (C) 2011-2022 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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<https://www.gnu.org/licenses/>. */
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#include <math.h>
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#include <math_private.h>
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#include <libm-alias-finite.h>
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static FLOAT
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__attribute__ ((noinline))
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invalid_fn (FLOAT x, FLOAT fn)
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{
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if (M_SUF (rint) (fn) != fn)
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return (fn - fn) / (fn - fn);
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else if (fn > M_LIT (65000.0))
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return M_SUF (__scalbn) (x, 65000);
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else
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return M_SUF (__scalbn) (x,-65000);
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}
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FLOAT
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M_DECL_FUNC (__ieee754_scalb) (FLOAT x, FLOAT fn)
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{
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if (__glibc_unlikely (isnan (x)))
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return x * fn;
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if (__glibc_unlikely (!isfinite (fn)))
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{
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if (isnan (fn) || fn > M_LIT (0.0))
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return x * fn;
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if (x == M_LIT (0.0))
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return x;
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return x / -fn;
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}
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if (__glibc_unlikely (M_FABS (fn) >= M_LIT (0x1p31)
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|| (FLOAT) (int) fn != fn))
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return invalid_fn (x, fn);
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return M_SCALBN (x, (int) fn);
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}
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declare_mgen_finite_alias (__ieee754_scalb, __scalb)
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