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a2c8310fb0
* sysdeps/m68k/fpu/s_frexp.c: Put implementation here. * sysdeps/m68k/fpu/s_frexpl.c: Fix to handle unnormalized numbers.
60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/* Copyright (C) 2003 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, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <math.h>
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long double
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__frexpl (long double value, int *expptr)
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{
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long double mantissa, exponent;
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int iexponent;
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unsigned long fpsr;
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__asm ("ftst%.x %1\n"
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"fmove%.l %/fpsr, %0"
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: "=dm" (fpsr) : "f" (value));
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if (fpsr & (7 << 24))
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{
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/* Not finite or zero. */
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*expptr = 0;
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return value;
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}
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__asm ("fgetexp%.x %1, %0" : "=f" (exponent) : "f" (value));
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iexponent = (int) exponent + 1;
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*expptr = iexponent;
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/* Unnormalized numbers must be handled specially, otherwise fscale
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results in overflow. */
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if (iexponent <= -16384)
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{
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value *= 0x1p16383L;
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iexponent += 16383;
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}
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else if (iexponent >= 16384)
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{
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value *= 0x1p-16383L;
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iexponent -= 16383;
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}
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__asm ("fscale%.l %2, %0"
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: "=f" (mantissa)
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: "0" (value), "dmi" (-iexponent));
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return mantissa;
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}
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weak_alias (__frexpl, frexpl)
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