about summary refs log tree commit diff
path: root/sysdeps/powerpc/q_feq.c
blob: 3f5512a4a0b9bae66ff3a5faaee6d270d172060d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
/* 128-bit floating point unordered equality.
   Copyright (C) 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <fenv_libc.h>

/* int _q_feq(const long double *a, const long double *b);
   Returns nonzero if a==b, 0 otherwise.

   Special cases:
   NaNs are never equal to anything;
   -0 == +0;
   If either argument is a SNaN, we set FPSCR_VXSNAN to cause an
   'invalid operation' exception.
   */

int
__q_feq(const unsigned a[4], const unsigned b[4])
{
  unsigned a0, b0;

  a0 = a[0]; b0 = b[0];

  if ((a0 >> 16  &  0x7fff) != 0x7fff &&
      (b0 >> 16  &  0x7fff) != 0x7fff)
    {
      unsigned a3,b3,a2,b2,a1,b1;
      unsigned z, result;

      a3 = a[3]; b3 = b[3]; a2 = a[2];
      b2 = b[2]; a1 = a[1]; b1 = b[1];
      result = ~(a3 ^ b3);
      result &= ~(a2 ^ b2);
      result &= ~(a1 ^ b1);
      z = a3 | a2;
      z |= a1;
      z = (z >> 1 | z | a0) & 0x7fffffff;
      /* 'z' is 0 iff a==0.0, otherwise between 1 and 0x7fffffff */
      return (result & ~(a0^b0 & ~(-z & 0x80000000)))+1;
    }
  else
    {
      /* Deal with SNaNs */
      if (((a0|b0) & 0x8000) == 0)
	{
	  set_fpscr_bit(FPSCR_VXSNAN);
	}
      return 0;
    }
}