diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c b/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c deleted file mode 100644 index 21d1e62..0000000 --- a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c +++ /dev/null @@ -1,152 +0,0 @@ -/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2002, 2003, 2004, 2006, 2007 - 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 Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -#include "gmp.h" -#include "gmp-impl.h" -#include <ieee754.h> -#include <float.h> -#include <math.h> - -/* Convert a multi-precision integer of the needed number of bits (106 - for long double) and an integral power of two to a `long double' in - IBM extended format. */ - -long double -__mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign) -{ - union ibm_extended_long_double u; - unsigned long lzcount; - unsigned long long hi, lo; - int exponent2; - - u.ieee.negative = sign; - u.ieee.negative2 = sign; - u.ieee.exponent = expt + IBM_EXTENDED_LONG_DOUBLE_BIAS; - u.ieee.exponent2 = 0; - exponent2 = expt - 53 + IBM_EXTENDED_LONG_DOUBLE_BIAS; - -#if BITS_PER_MP_LIMB == 32 - /* The low order 53 bits (52 + hidden) go into the lower double */ - lo = frac_ptr[0]; - lo |= (frac_ptr[1] & ((1LL << (53 - 32)) - 1)) << 32; - /* The high order 53 bits (52 + hidden) go into the upper double */ - hi = (frac_ptr[1] >> (53 - 32)) & ((1 << 11) - 1); - hi |= ((unsigned long long) frac_ptr[2]) << 11; - hi |= ((unsigned long long) frac_ptr[3]) << (32 + 11); -#elif BITS_PER_MP_LIMB == 64 - /* The low order 53 bits (52 + hidden) go into the lower double */ - lo = frac_ptr[0] & (((mp_limb_t) 1 << 53) - 1); - /* The high order 53 bits (52 + hidden) go into the upper double */ - hi = (frac_ptr[0] >> 53) & (((mp_limb_t) 1 << 11) - 1); - hi |= (frac_ptr[1] << 11); -#else - #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for" -#endif - - if ((hi & (1LL << 52)) == 0 && (hi | lo) != 0) - { - /* denormal number */ - unsigned long long val = hi ? hi : lo; - - if (sizeof (val) == sizeof (long)) - lzcount = __builtin_clzl (val); - else if ((val >> 32) != 0) - lzcount = __builtin_clzl ((long) (val >> 32)); - else - lzcount = __builtin_clzl ((long) val) + 32; - if (hi) - lzcount = lzcount - 11; - else - lzcount = lzcount + 42; - - if (lzcount > u.ieee.exponent) - { - lzcount = u.ieee.exponent; - u.ieee.exponent = 0; - exponent2 -= lzcount; - } - else - { - u.ieee.exponent -= (lzcount - 1); - exponent2 -= (lzcount - 1); - } - - if (lzcount <= 53) - { - hi = (hi << lzcount) | (lo >> (53 - lzcount)); - lo = (lo << lzcount) & ((1LL << 53) - 1); - } - else - { - hi = lo << (lzcount - 53); - lo = 0; - } - } - - if (lo != 0L) - { - /* hidden2 bit of low double controls rounding of the high double. - If hidden2 is '1' and either the explicit mantissa is non-zero - or hi is odd, then round up hi and adjust lo (2nd mantissa) - plus change the sign of the low double to compensate. */ - if ((lo & (1LL << 52)) != 0 - && ((hi & 1) != 0 || (lo & ((1LL << 52) - 1)))) - { - hi++; - if ((hi & ((1LL << 52) - 1)) == 0) - { - if ((hi & (1LL << 53)) != 0) - hi -= 1LL << 52; - u.ieee.exponent++; - } - u.ieee.negative2 = !sign; - lo = (1LL << 53) - lo; - } - - /* The hidden bit of the lo mantissa is zero so we need to normalize - it for the low double. Shift it left until the hidden bit is '1' - then adjust the 2nd exponent accordingly. */ - - if (sizeof (lo) == sizeof (long)) - lzcount = __builtin_clzl (lo); - else if ((lo >> 32) != 0) - lzcount = __builtin_clzl ((long) (lo >> 32)); - else - lzcount = __builtin_clzl ((long) lo) + 32; - lzcount = lzcount - 11; - if (lzcount > 0) - { - lo = lo << lzcount; - exponent2 = exponent2 - lzcount; - } - if (exponent2 > 0) - u.ieee.exponent2 = exponent2; - else - lo >>= 1 - exponent2; - } - else - u.ieee.negative2 = 0; - - u.ieee.mantissa3 = lo & 0xffffffffLL; - u.ieee.mantissa2 = (lo >> 32) & 0xfffff; - u.ieee.mantissa1 = hi & 0xffffffffLL; - u.ieee.mantissa0 = (hi >> 32) & ((1LL << (LDBL_MANT_DIG - 86)) - 1); - - return u.d; -} |