66 lines
1.9 KiB
C
66 lines
1.9 KiB
C
/* 128-bit floating point unordered equality.
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Copyright (C) 1997 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 Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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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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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <fenv_libc.h>
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/* int _q_feq(const long double *a, const long double *b);
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Returns nonzero if a==b, 0 otherwise.
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Special cases:
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NaNs are never equal to anything;
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-0 == +0;
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If either argument is a SNaN, we set FPSCR_VXSNAN to cause an
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'invalid operation' exception.
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*/
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int
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__q_feq(const unsigned a[4], const unsigned b[4])
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{
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unsigned a0, b0;
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a0 = a[0]; b0 = b[0];
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if ((a0 >> 16 & 0x7fff) != 0x7fff &&
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(b0 >> 16 & 0x7fff) != 0x7fff)
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{
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unsigned a3,b3,a2,b2,a1,b1;
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unsigned z, result;
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a3 = a[3]; b3 = b[3]; a2 = a[2];
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b2 = b[2]; a1 = a[1]; b1 = b[1];
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result = ~(a3 ^ b3);
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result &= ~(a2 ^ b2);
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result &= ~(a1 ^ b1);
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z = a3 | a2;
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z |= a1;
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z = (z >> 1 | z | a0) & 0x7fffffff;
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/* 'z' is 0 iff a==0.0, otherwise between 1 and 0x7fffffff */
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return (result & ~(a0^b0 & ~(-z & 0x80000000)))+1;
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}
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else
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{
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/* Deal with SNaNs */
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if (((a0|b0) & 0x8000) == 0)
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{
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set_fpscr_bit(FPSCR_VXSNAN);
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}
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return 0;
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}
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}
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