gcc/libquadmath/printf/flt1282mpn.c
Joseph Myers 667b3ec15d Update libquadmath fmaq from glibc, fix nanq issues.
This patch extends update-quadmath.py to update fmaq from glibc.

The issue in that function was that quadmath-imp.h had a struct in a
union with mant_high and mant_low fields (up to 64-bit) whereas glibc
has mantissa0, mantissa1, mantissa2 and mantissa3 (up to 32-bit).  The
patch changes those fields to be the same as in glibc, moving printf /
strtod code that also uses those fields back to closer to the glibc
form.  This allows fmaq to be updated automatically from glibc (which
brings in at least one bug fix from glibc from 2015).

nanq was also using the mant_high field name, and had other issues: it
only partly initialized the union from which a value was returned, and
setting mant_high to 1 meant a signaling NaN would be returned rather
than a quiet NaN.  This patch fixes those issues as part of updating
it to use the changed interfaces (but does not fix the issue of not
using the argument).

Bootstrapped with no regressions on x86_64-pc-linux-gnu.

	* quadmath-imp.h (ieee854_float128): Use mantissa0, mantissa1,
	mantissa2 and mantissa3 fields instead of mant_high and mant_low.
	Change nan field to ieee_nan.
	* update-quadmath.py (update_sources): Also update fmaq.c.
	* math/nanq.c (nanq): Use ieee_nan field of union.
	Zero-initialize f.  Set quiet_nan field.
	* printf/flt1282mpn.c, printf/printf_fphex.c, strtod/mpn2flt128.c,
	strtod/strtoflt128.c: Use mantissa0, mantissa1, mantissa2 and
	mantissa3 fields.  Use ieee_nan and quiet_nan field.
	* math/fmaq.c: Regenerate from glibc sources with
	update-quadmath.py.

From-SVN: r265874
2018-11-07 13:49:03 +00:00

137 lines
4.0 KiB
C

/* Copyright (C) 1995,1996,1997,1998,1999,2002,2003
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 <float.h>
#include <math.h>
#include <stdlib.h>
#include "gmp-impl.h"
/* Convert a `__float128' in IEEE854 quad-precision format to a
multi-precision integer representing the significand scaled up by its
number of bits (113 for long double) and an integral power of two
(MPN frexpl). */
mp_size_t
mpn_extract_flt128 (mp_ptr res_ptr, mp_size_t size,
int *expt, int *is_neg,
__float128 value)
{
ieee854_float128 u;
u.value = value;
*is_neg = u.ieee.negative;
*expt = (int) u.ieee.exponent - IEEE854_FLOAT128_BIAS;
#if BITS_PER_MP_LIMB == 32
res_ptr[0] = u.ieee.mantissa3; /* Low-order 32 bits of fraction. */
res_ptr[1] = u.ieee.mantissa2;
res_ptr[2] = u.ieee.mantissa1;
res_ptr[3] = u.ieee.mantissa0; /* High-order 32 bits. */
#define N 4
#elif BITS_PER_MP_LIMB == 64
res_ptr[0] = ((mp_limb_t) u.ieee.mantissa2 << 32) | u.ieee.mantissa3;
res_ptr[1] = ((mp_limb_t) u.ieee.mantissa0 << 32) | u.ieee.mantissa1;
#define N 2
#else
#error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
/* The format does not fill the last limb. There are some zeros. */
#define NUM_LEADING_ZEROS (BITS_PER_MP_LIMB \
- (FLT128_MANT_DIG - ((N - 1) * BITS_PER_MP_LIMB)))
if (u.ieee.exponent == 0)
{
/* A biased exponent of zero is a special case.
Either it is a zero or it is a denormal number. */
if (res_ptr[0] == 0 && res_ptr[1] == 0
&& res_ptr[N - 2] == 0 && res_ptr[N - 1] == 0) /* Assumes N<=4. */
/* It's zero. */
*expt = 0;
else
{
/* It is a denormal number, meaning it has no implicit leading
one bit, and its exponent is in fact the format minimum. */
int cnt;
#if N == 2
if (res_ptr[N - 1] != 0)
{
count_leading_zeros (cnt, res_ptr[N - 1]);
cnt -= NUM_LEADING_ZEROS;
res_ptr[N - 1] = res_ptr[N - 1] << cnt
| (res_ptr[0] >> (BITS_PER_MP_LIMB - cnt));
res_ptr[0] <<= cnt;
*expt = FLT128_MIN_EXP - 1 - cnt;
}
else
{
count_leading_zeros (cnt, res_ptr[0]);
if (cnt >= NUM_LEADING_ZEROS)
{
res_ptr[N - 1] = res_ptr[0] << (cnt - NUM_LEADING_ZEROS);
res_ptr[0] = 0;
}
else
{
res_ptr[N - 1] = res_ptr[0] >> (NUM_LEADING_ZEROS - cnt);
res_ptr[0] <<= BITS_PER_MP_LIMB - (NUM_LEADING_ZEROS - cnt);
}
*expt = FLT128_MIN_EXP - 1
- (BITS_PER_MP_LIMB - NUM_LEADING_ZEROS) - cnt;
}
#else
int j, k, l;
for (j = N - 1; j > 0; j--)
if (res_ptr[j] != 0)
break;
count_leading_zeros (cnt, res_ptr[j]);
cnt -= NUM_LEADING_ZEROS;
l = N - 1 - j;
if (cnt < 0)
{
cnt += BITS_PER_MP_LIMB;
l--;
}
if (!cnt)
for (k = N - 1; k >= l; k--)
res_ptr[k] = res_ptr[k-l];
else
{
for (k = N - 1; k > l; k--)
res_ptr[k] = res_ptr[k-l] << cnt
| res_ptr[k-l-1] >> (BITS_PER_MP_LIMB - cnt);
res_ptr[k--] = res_ptr[0] << cnt;
}
for (; k >= 0; k--)
res_ptr[k] = 0;
*expt = FLT128_MIN_EXP - 1 - l * BITS_PER_MP_LIMB - cnt;
#endif
}
}
else
/* Add the implicit leading one bit for a normalized number. */
res_ptr[N - 1] |= (mp_limb_t) 1 << (FLT128_MANT_DIG - 1
- ((N - 1) * BITS_PER_MP_LIMB));
return N;
}