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Diffstat (limited to 'sysdeps/powerpc/q_qtos.c')
| -rw-r--r-- | sysdeps/powerpc/q_qtos.c | 84 |
1 files changed, 0 insertions, 84 deletions
diff --git a/sysdeps/powerpc/q_qtos.c b/sysdeps/powerpc/q_qtos.c deleted file mode 100644 index cd2715f8e9..0000000000 --- a/sysdeps/powerpc/q_qtos.c +++ /dev/null @@ -1,84 +0,0 @@ -/* 128-bit floating point to 32-bit floating point. - 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> - -/* float _q_qtos(const long double *a); - Convert 'a' to float. Round as per current rounding flags. - - Input Rounding Output - +/-0 * +/-0 - +/-Inf * +/-Inf - +/-NaN * +/-NaN (with mantissa truncated) - +/-SNaN * +/-NaN (with mantissa truncated, MSB of mantissa <- 1) - && raise VXSNAN - [Note: just truncating the mantissa may not give you - a SNaN!] - |a|>=2^128 Nearest +/-Inf && raise overflow && raise inexact - |a|>=2^128 Truncate +/-(2^128-2^104) && raise overflow && raise inexact - a>=2^128 +Inf +Inf && raise overflow && raise inexact - a<=-2^128 +Inf -(2^128-2^104) && raise overflow && raise inexact - a>=2^128 -Inf +(2^128-2^104) && raise overflow && raise inexact - a<=-2^128 -Inf -Inf && raise overflow && raise inexact - - We also need to raise 'inexact' if the result will be inexact, which - depends on the current rounding mode. - - To avoid having to deal with all that, we convert to a 'double' - that will round correctly (but is not itself rounded correctly), - and convert that to a float. This makes this procedure much - simpler and much faster. */ - -float -__q_qtos(const unsigned long long a[2]) -{ - unsigned long long a0,d; - union { - double d; - unsigned long long ull; - } u; - - a0 = a[0]; - - /* Truncate the mantissa to 48 bits. */ - d = a0 << 4; - /* Set the low bit in the mantissa if any of the bits we are dropping - were 1. This ensures correct rounding, and also distinguishes - 0 and Inf from denormalised numbers and SNaN (respectively). */ - d |= a[1] != 0; - /* Copy the sign bit. */ - d = d & 0x7fffffffffffffffULL | a0 & 0x8000000000000000ULL; - - /* Now, we need to fix the exponent. If the exponent of a was in - the range +127 to -152, or was +16384 or -16383, it is already - correct in 'd'. Otherwise, we need to ensure that the new - exponent is in the range +1023 to +128, or -153 to -1022, with - the same sign as the exponent of 'a'. We can do this by setting - bits 1-3 (the second through fourth-most significant bit) of 'd' - to 101 if bit 1 of 'a' is 1, or 010 if bit 1 of 'a' is 0. */ - if ((a0 >> 56 & 0x7f) - 0x3f > 1) - { - unsigned t = (a0 >> 32+2 & 2 << 31-1-2)*3 + (2 << 31-2); - d = (d & 0x8fffffffffffffffULL - | (unsigned long long)t<<32 & 0x7000000000000000ULL); - } - - u.ull = d; - return (float)u.d; -} |