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/* 128-bit floating point to 32-bit fixed point signed integer.
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 <quad_float.h>
/* int _q_qtoi(const long double *a);
Convert 'a' to signed int by truncation.
Special cases:
NaN: raise VXCVI, return 0x80000000
SNaN: raise VXSNAN, VXCVI, and return 0x80000000
>= 2^32: raise VXCVI, return 0x7fffffff
<= -2^32: raise VXCVI, return 0x80000000
*/
int
__q_qtoi(const unsigned long long a[2])
{
int ax, sgn;
unsigned long long a0;
a0 = a[0];
/* 'sgn' is -1 if 'a' is negative, 0 if positive. */
sgn = (long long)a0 >> 63;
ax = (a0 >> 48 & 0x7fff) - 16383;
/* Deal with non-special cases. */
if (ax <= 30)
/* If we had a '>>' operator that behaved properly with respect to
large shifts, we wouldn't need the '& -(ax >> 31)' term, which
clears 'result' if ax is negative. The '^ sgn) - sgn' part is
equivalent in this case to multiplication by 'sgn', but usually
faster. */
return (((unsigned)(a0 >> 17 | 0x80000000) >> 31-ax & -(ax >> 31))
^ sgn) - sgn;
/* Check for SNaN, if so raise VXSNAN. */
if ((a0 >> 32 & 0x7fff8000) == 0x7fff0000
&& (a[1] | a0 & 0x00007fffffffffffULL) != 0)
set_fpscr_bit(FPSCR_VXSNAN);
/* Treat all NaNs as large negative numbers. */
sgn |= -cntlzw(~(a0 >> 32) & 0x7fff0000) >> 5;
/* All the specials raise VXCVI. */
set_fpscr_bit(FPSCR_VXCVI);
/* Return 0x7fffffff (if a < 0) or 0x80000000 (otherwise). */
return sgn ^ 0x7fffffff;
}
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