1998-03-01 22:58:51 +00:00
|
|
|
|
/* atof_ieee.c - turn a Flonum into an IEEE floating point number
|
1998-09-06 22:57:45 +00:00
|
|
|
|
Copyright (C) 1987, 92, 93, 94, 95, 96, 97, 1998
|
|
|
|
|
|
Free Software Foundation, Inc.
|
1998-03-01 22:58:51 +00:00
|
|
|
|
|
|
|
|
|
|
This file is part of GAS, the GNU Assembler.
|
|
|
|
|
|
|
|
|
|
|
|
GAS is free software; you can redistribute it and/or modify
|
|
|
|
|
|
it under the terms of the GNU General Public License as published by
|
|
|
|
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
|
|
|
|
any later version.
|
|
|
|
|
|
|
|
|
|
|
|
GAS 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 General Public License for more details.
|
|
|
|
|
|
|
|
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
|
|
|
|
along with GAS; see the file COPYING. If not, write to the Free
|
|
|
|
|
|
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
|
|
|
|
|
02111-1307, USA. */
|
|
|
|
|
|
|
|
|
|
|
|
#include "as.h"
|
|
|
|
|
|
|
|
|
|
|
|
/* Flonums returned here. */
|
|
|
|
|
|
extern FLONUM_TYPE generic_floating_point_number;
|
|
|
|
|
|
|
|
|
|
|
|
static int next_bits PARAMS ((int));
|
|
|
|
|
|
static void unget_bits PARAMS ((int));
|
|
|
|
|
|
static void make_invalid_floating_point_number PARAMS ((LITTLENUM_TYPE *));
|
|
|
|
|
|
|
|
|
|
|
|
extern const char EXP_CHARS[];
|
|
|
|
|
|
/* Precision in LittleNums. */
|
|
|
|
|
|
/* Don't count the gap in the m68k extended precision format. */
|
|
|
|
|
|
#define MAX_PRECISION (5)
|
|
|
|
|
|
#define F_PRECISION (2)
|
|
|
|
|
|
#define D_PRECISION (4)
|
|
|
|
|
|
#define X_PRECISION (5)
|
|
|
|
|
|
#define P_PRECISION (5)
|
|
|
|
|
|
|
|
|
|
|
|
/* Length in LittleNums of guard bits. */
|
|
|
|
|
|
#define GUARD (2)
|
|
|
|
|
|
|
|
|
|
|
|
static const unsigned long mask[] =
|
|
|
|
|
|
{
|
|
|
|
|
|
0x00000000,
|
|
|
|
|
|
0x00000001,
|
|
|
|
|
|
0x00000003,
|
|
|
|
|
|
0x00000007,
|
|
|
|
|
|
0x0000000f,
|
|
|
|
|
|
0x0000001f,
|
|
|
|
|
|
0x0000003f,
|
|
|
|
|
|
0x0000007f,
|
|
|
|
|
|
0x000000ff,
|
|
|
|
|
|
0x000001ff,
|
|
|
|
|
|
0x000003ff,
|
|
|
|
|
|
0x000007ff,
|
|
|
|
|
|
0x00000fff,
|
|
|
|
|
|
0x00001fff,
|
|
|
|
|
|
0x00003fff,
|
|
|
|
|
|
0x00007fff,
|
|
|
|
|
|
0x0000ffff,
|
|
|
|
|
|
0x0001ffff,
|
|
|
|
|
|
0x0003ffff,
|
|
|
|
|
|
0x0007ffff,
|
|
|
|
|
|
0x000fffff,
|
|
|
|
|
|
0x001fffff,
|
|
|
|
|
|
0x003fffff,
|
|
|
|
|
|
0x007fffff,
|
|
|
|
|
|
0x00ffffff,
|
|
|
|
|
|
0x01ffffff,
|
|
|
|
|
|
0x03ffffff,
|
|
|
|
|
|
0x07ffffff,
|
|
|
|
|
|
0x0fffffff,
|
|
|
|
|
|
0x1fffffff,
|
|
|
|
|
|
0x3fffffff,
|
|
|
|
|
|
0x7fffffff,
|
|
|
|
|
|
0xffffffff,
|
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
static int bits_left_in_littlenum;
|
|
|
|
|
|
static int littlenums_left;
|
|
|
|
|
|
static LITTLENUM_TYPE *littlenum_pointer;
|
|
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
|
|
next_bits (number_of_bits)
|
|
|
|
|
|
int number_of_bits;
|
|
|
|
|
|
{
|
|
|
|
|
|
int return_value;
|
|
|
|
|
|
|
|
|
|
|
|
if (!littlenums_left)
|
|
|
|
|
|
return (0);
|
|
|
|
|
|
if (number_of_bits >= bits_left_in_littlenum)
|
|
|
|
|
|
{
|
|
|
|
|
|
return_value = mask[bits_left_in_littlenum] & *littlenum_pointer;
|
|
|
|
|
|
number_of_bits -= bits_left_in_littlenum;
|
|
|
|
|
|
return_value <<= number_of_bits;
|
|
|
|
|
|
|
|
|
|
|
|
if (--littlenums_left)
|
|
|
|
|
|
{
|
|
|
|
|
|
bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits;
|
|
|
|
|
|
--littlenum_pointer;
|
|
|
|
|
|
return_value |= (*littlenum_pointer >> bits_left_in_littlenum) & mask[number_of_bits];
|
|
|
|
|
|
}
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
bits_left_in_littlenum -= number_of_bits;
|
|
|
|
|
|
return_value = mask[number_of_bits] & (*littlenum_pointer >> bits_left_in_littlenum);
|
|
|
|
|
|
}
|
|
|
|
|
|
return (return_value);
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Num had better be less than LITTLENUM_NUMBER_OF_BITS */
|
|
|
|
|
|
static void
|
|
|
|
|
|
unget_bits (num)
|
|
|
|
|
|
int num;
|
|
|
|
|
|
{
|
|
|
|
|
|
if (!littlenums_left)
|
|
|
|
|
|
{
|
|
|
|
|
|
++littlenum_pointer;
|
|
|
|
|
|
++littlenums_left;
|
|
|
|
|
|
bits_left_in_littlenum = num;
|
|
|
|
|
|
}
|
|
|
|
|
|
else if (bits_left_in_littlenum + num > LITTLENUM_NUMBER_OF_BITS)
|
|
|
|
|
|
{
|
|
|
|
|
|
bits_left_in_littlenum = num - (LITTLENUM_NUMBER_OF_BITS - bits_left_in_littlenum);
|
|
|
|
|
|
++littlenum_pointer;
|
|
|
|
|
|
++littlenums_left;
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
bits_left_in_littlenum += num;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static void
|
|
|
|
|
|
make_invalid_floating_point_number (words)
|
|
|
|
|
|
LITTLENUM_TYPE *words;
|
|
|
|
|
|
{
|
|
|
|
|
|
as_bad ("cannot create floating-point number");
|
|
|
|
|
|
words[0] = (LITTLENUM_TYPE) ((unsigned) -1) >> 1; /* Zero the leftmost bit */
|
|
|
|
|
|
words[1] = (LITTLENUM_TYPE) -1;
|
|
|
|
|
|
words[2] = (LITTLENUM_TYPE) -1;
|
|
|
|
|
|
words[3] = (LITTLENUM_TYPE) -1;
|
|
|
|
|
|
words[4] = (LITTLENUM_TYPE) -1;
|
|
|
|
|
|
words[5] = (LITTLENUM_TYPE) -1;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/************************************************************************\
|
|
|
|
|
|
* Warning: this returns 16-bit LITTLENUMs. It is up to the caller *
|
|
|
|
|
|
* to figure out any alignment problems and to conspire for the *
|
|
|
|
|
|
* bytes/word to be emitted in the right order. Bigendians beware! *
|
|
|
|
|
|
* *
|
|
|
|
|
|
\************************************************************************/
|
|
|
|
|
|
|
|
|
|
|
|
/* Note that atof-ieee always has X and P precisions enabled. it is up
|
|
|
|
|
|
to md_atof to filter them out if the target machine does not support
|
|
|
|
|
|
them. */
|
|
|
|
|
|
|
|
|
|
|
|
/* Returns pointer past text consumed. */
|
|
|
|
|
|
char *
|
|
|
|
|
|
atof_ieee (str, what_kind, words)
|
|
|
|
|
|
char *str; /* Text to convert to binary. */
|
|
|
|
|
|
char what_kind; /* 'd', 'f', 'g', 'h' */
|
|
|
|
|
|
LITTLENUM_TYPE *words; /* Build the binary here. */
|
|
|
|
|
|
{
|
|
|
|
|
|
/* Extra bits for zeroed low-order bits. The 1st MAX_PRECISION are
|
|
|
|
|
|
zeroed, the last contain flonum bits. */
|
|
|
|
|
|
static LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD];
|
|
|
|
|
|
char *return_value;
|
|
|
|
|
|
/* Number of 16-bit words in the format. */
|
|
|
|
|
|
int precision;
|
|
|
|
|
|
long exponent_bits;
|
|
|
|
|
|
FLONUM_TYPE save_gen_flonum;
|
|
|
|
|
|
|
|
|
|
|
|
/* We have to save the generic_floating_point_number because it
|
|
|
|
|
|
contains storage allocation about the array of LITTLENUMs where
|
|
|
|
|
|
the value is actually stored. We will allocate our own array of
|
|
|
|
|
|
littlenums below, but have to restore the global one on exit. */
|
|
|
|
|
|
save_gen_flonum = generic_floating_point_number;
|
|
|
|
|
|
|
|
|
|
|
|
return_value = str;
|
|
|
|
|
|
generic_floating_point_number.low = bits + MAX_PRECISION;
|
|
|
|
|
|
generic_floating_point_number.high = NULL;
|
|
|
|
|
|
generic_floating_point_number.leader = NULL;
|
|
|
|
|
|
generic_floating_point_number.exponent = 0;
|
|
|
|
|
|
generic_floating_point_number.sign = '\0';
|
|
|
|
|
|
|
|
|
|
|
|
/* Use more LittleNums than seems necessary: the highest flonum may
|
|
|
|
|
|
have 15 leading 0 bits, so could be useless. */
|
|
|
|
|
|
|
|
|
|
|
|
memset (bits, '\0', sizeof (LITTLENUM_TYPE) * MAX_PRECISION);
|
|
|
|
|
|
|
|
|
|
|
|
switch (what_kind)
|
|
|
|
|
|
{
|
|
|
|
|
|
case 'f':
|
|
|
|
|
|
case 'F':
|
|
|
|
|
|
case 's':
|
|
|
|
|
|
case 'S':
|
|
|
|
|
|
precision = F_PRECISION;
|
|
|
|
|
|
exponent_bits = 8;
|
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
|
|
case 'd':
|
|
|
|
|
|
case 'D':
|
|
|
|
|
|
case 'r':
|
|
|
|
|
|
case 'R':
|
|
|
|
|
|
precision = D_PRECISION;
|
|
|
|
|
|
exponent_bits = 11;
|
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
|
|
case 'x':
|
|
|
|
|
|
case 'X':
|
|
|
|
|
|
case 'e':
|
|
|
|
|
|
case 'E':
|
|
|
|
|
|
precision = X_PRECISION;
|
|
|
|
|
|
exponent_bits = 15;
|
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
|
|
case 'p':
|
|
|
|
|
|
case 'P':
|
|
|
|
|
|
|
|
|
|
|
|
precision = P_PRECISION;
|
|
|
|
|
|
exponent_bits = -1;
|
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
|
|
default:
|
|
|
|
|
|
make_invalid_floating_point_number (words);
|
|
|
|
|
|
return (NULL);
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
generic_floating_point_number.high
|
|
|
|
|
|
= generic_floating_point_number.low + precision - 1 + GUARD;
|
|
|
|
|
|
|
|
|
|
|
|
if (atof_generic (&return_value, ".", EXP_CHARS,
|
|
|
|
|
|
&generic_floating_point_number))
|
|
|
|
|
|
{
|
|
|
|
|
|
make_invalid_floating_point_number (words);
|
|
|
|
|
|
return (NULL);
|
|
|
|
|
|
}
|
|
|
|
|
|
gen_to_words (words, precision, exponent_bits);
|
|
|
|
|
|
|
|
|
|
|
|
/* Restore the generic_floating_point_number's storage alloc (and
|
|
|
|
|
|
everything else). */
|
|
|
|
|
|
generic_floating_point_number = save_gen_flonum;
|
|
|
|
|
|
|
|
|
|
|
|
return return_value;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Turn generic_floating_point_number into a real float/double/extended. */
|
|
|
|
|
|
int
|
|
|
|
|
|
gen_to_words (words, precision, exponent_bits)
|
|
|
|
|
|
LITTLENUM_TYPE *words;
|
|
|
|
|
|
int precision;
|
|
|
|
|
|
long exponent_bits;
|
|
|
|
|
|
{
|
|
|
|
|
|
int return_value = 0;
|
|
|
|
|
|
|
|
|
|
|
|
long exponent_1;
|
|
|
|
|
|
long exponent_2;
|
|
|
|
|
|
long exponent_3;
|
|
|
|
|
|
long exponent_4;
|
|
|
|
|
|
int exponent_skippage;
|
|
|
|
|
|
LITTLENUM_TYPE word1;
|
|
|
|
|
|
LITTLENUM_TYPE *lp;
|
|
|
|
|
|
LITTLENUM_TYPE *words_end;
|
|
|
|
|
|
|
|
|
|
|
|
words_end = words + precision;
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
if (precision == X_PRECISION)
|
|
|
|
|
|
/* On the m68k the extended precision format has a gap of 16 bits
|
|
|
|
|
|
between the exponent and the mantissa. */
|
|
|
|
|
|
words_end++;
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
if (generic_floating_point_number.low > generic_floating_point_number.leader)
|
|
|
|
|
|
{
|
|
|
|
|
|
/* 0.0e0 seen. */
|
|
|
|
|
|
if (generic_floating_point_number.sign == '+')
|
|
|
|
|
|
words[0] = 0x0000;
|
|
|
|
|
|
else
|
|
|
|
|
|
words[0] = 0x8000;
|
|
|
|
|
|
memset (&words[1], '\0',
|
|
|
|
|
|
(words_end - words - 1) * sizeof (LITTLENUM_TYPE));
|
|
|
|
|
|
return (return_value);
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* NaN: Do the right thing */
|
|
|
|
|
|
if (generic_floating_point_number.sign == 0)
|
|
|
|
|
|
{
|
|
|
|
|
|
if (precision == F_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
words[0] = 0x7fff;
|
|
|
|
|
|
words[1] = 0xffff;
|
|
|
|
|
|
}
|
|
|
|
|
|
else if (precision == X_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
words[0] = 0x7fff;
|
|
|
|
|
|
words[1] = 0;
|
|
|
|
|
|
words[2] = 0xffff;
|
|
|
|
|
|
words[3] = 0xffff;
|
|
|
|
|
|
words[4] = 0xffff;
|
|
|
|
|
|
words[5] = 0xffff;
|
|
|
|
|
|
#else /* ! TC_M68K */
|
|
|
|
|
|
#ifdef TC_I386
|
|
|
|
|
|
words[0] = 0xffff;
|
|
|
|
|
|
words[1] = 0xc000;
|
|
|
|
|
|
words[2] = 0;
|
|
|
|
|
|
words[3] = 0;
|
|
|
|
|
|
words[4] = 0;
|
|
|
|
|
|
#else /* ! TC_I386 */
|
|
|
|
|
|
abort ();
|
|
|
|
|
|
#endif /* ! TC_I386 */
|
|
|
|
|
|
#endif /* ! TC_M68K */
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
words[0] = 0x7fff;
|
|
|
|
|
|
words[1] = 0xffff;
|
|
|
|
|
|
words[2] = 0xffff;
|
|
|
|
|
|
words[3] = 0xffff;
|
|
|
|
|
|
}
|
|
|
|
|
|
return return_value;
|
|
|
|
|
|
}
|
|
|
|
|
|
else if (generic_floating_point_number.sign == 'P')
|
|
|
|
|
|
{
|
|
|
|
|
|
/* +INF: Do the right thing */
|
|
|
|
|
|
if (precision == F_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
words[0] = 0x7f80;
|
|
|
|
|
|
words[1] = 0;
|
|
|
|
|
|
}
|
|
|
|
|
|
else if (precision == X_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
words[0] = 0x7fff;
|
|
|
|
|
|
words[1] = 0;
|
|
|
|
|
|
words[2] = 0;
|
|
|
|
|
|
words[3] = 0;
|
|
|
|
|
|
words[4] = 0;
|
|
|
|
|
|
words[5] = 0;
|
|
|
|
|
|
#else /* ! TC_M68K */
|
|
|
|
|
|
#ifdef TC_I386
|
|
|
|
|
|
words[0] = 0x7fff;
|
|
|
|
|
|
words[1] = 0x8000;
|
|
|
|
|
|
words[2] = 0;
|
|
|
|
|
|
words[3] = 0;
|
|
|
|
|
|
words[4] = 0;
|
|
|
|
|
|
#else /* ! TC_I386 */
|
|
|
|
|
|
abort ();
|
|
|
|
|
|
#endif /* ! TC_I386 */
|
|
|
|
|
|
#endif /* ! TC_M68K */
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
words[0] = 0x7ff0;
|
|
|
|
|
|
words[1] = 0;
|
|
|
|
|
|
words[2] = 0;
|
|
|
|
|
|
words[3] = 0;
|
|
|
|
|
|
}
|
|
|
|
|
|
return (return_value);
|
|
|
|
|
|
}
|
|
|
|
|
|
else if (generic_floating_point_number.sign == 'N')
|
|
|
|
|
|
{
|
|
|
|
|
|
/* Negative INF */
|
|
|
|
|
|
if (precision == F_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
words[0] = 0xff80;
|
|
|
|
|
|
words[1] = 0x0;
|
|
|
|
|
|
}
|
|
|
|
|
|
else if (precision == X_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
words[0] = 0xffff;
|
|
|
|
|
|
words[1] = 0;
|
|
|
|
|
|
words[2] = 0;
|
|
|
|
|
|
words[3] = 0;
|
|
|
|
|
|
words[4] = 0;
|
|
|
|
|
|
words[5] = 0;
|
|
|
|
|
|
#else /* ! TC_M68K */
|
|
|
|
|
|
#ifdef TC_I386
|
|
|
|
|
|
words[0] = 0xffff;
|
|
|
|
|
|
words[1] = 0x8000;
|
|
|
|
|
|
words[2] = 0;
|
|
|
|
|
|
words[3] = 0;
|
|
|
|
|
|
words[4] = 0;
|
|
|
|
|
|
#else /* ! TC_I386 */
|
|
|
|
|
|
abort ();
|
|
|
|
|
|
#endif /* ! TC_I386 */
|
|
|
|
|
|
#endif /* ! TC_M68K */
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
words[0] = 0xfff0;
|
|
|
|
|
|
words[1] = 0x0;
|
|
|
|
|
|
words[2] = 0x0;
|
|
|
|
|
|
words[3] = 0x0;
|
|
|
|
|
|
}
|
|
|
|
|
|
return (return_value);
|
|
|
|
|
|
}
|
|
|
|
|
|
/*
|
|
|
|
|
|
* The floating point formats we support have:
|
|
|
|
|
|
* Bit 15 is sign bit.
|
|
|
|
|
|
* Bits 14:n are excess-whatever exponent.
|
|
|
|
|
|
* Bits n-1:0 (if any) are most significant bits of fraction.
|
|
|
|
|
|
* Bits 15:0 of the next word(s) are the next most significant bits.
|
|
|
|
|
|
*
|
|
|
|
|
|
* So we need: number of bits of exponent, number of bits of
|
|
|
|
|
|
* mantissa.
|
|
|
|
|
|
*/
|
|
|
|
|
|
bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
|
|
|
|
|
|
littlenum_pointer = generic_floating_point_number.leader;
|
|
|
|
|
|
littlenums_left = (1
|
|
|
|
|
|
+ generic_floating_point_number.leader
|
|
|
|
|
|
- generic_floating_point_number.low);
|
|
|
|
|
|
/* Seek (and forget) 1st significant bit */
|
|
|
|
|
|
for (exponent_skippage = 0; !next_bits (1); ++exponent_skippage);;
|
|
|
|
|
|
exponent_1 = (generic_floating_point_number.exponent
|
|
|
|
|
|
+ generic_floating_point_number.leader
|
|
|
|
|
|
+ 1
|
|
|
|
|
|
- generic_floating_point_number.low);
|
|
|
|
|
|
/* Radix LITTLENUM_RADIX, point just higher than
|
|
|
|
|
|
generic_floating_point_number.leader. */
|
|
|
|
|
|
exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS;
|
|
|
|
|
|
/* Radix 2. */
|
|
|
|
|
|
exponent_3 = exponent_2 - exponent_skippage;
|
|
|
|
|
|
/* Forget leading zeros, forget 1st bit. */
|
|
|
|
|
|
exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2);
|
|
|
|
|
|
/* Offset exponent. */
|
|
|
|
|
|
|
|
|
|
|
|
lp = words;
|
|
|
|
|
|
|
|
|
|
|
|
/* Word 1. Sign, exponent and perhaps high bits. */
|
|
|
|
|
|
word1 = ((generic_floating_point_number.sign == '+')
|
|
|
|
|
|
? 0
|
|
|
|
|
|
: (1 << (LITTLENUM_NUMBER_OF_BITS - 1)));
|
|
|
|
|
|
|
|
|
|
|
|
/* Assume 2's complement integers. */
|
|
|
|
|
|
if (exponent_4 <= 0)
|
|
|
|
|
|
{
|
|
|
|
|
|
int prec_bits;
|
|
|
|
|
|
int num_bits;
|
|
|
|
|
|
|
|
|
|
|
|
unget_bits (1);
|
|
|
|
|
|
num_bits = -exponent_4;
|
|
|
|
|
|
prec_bits = LITTLENUM_NUMBER_OF_BITS * precision - (exponent_bits + 1 + num_bits);
|
|
|
|
|
|
#ifdef TC_I386
|
|
|
|
|
|
if (precision == X_PRECISION && exponent_bits == 15)
|
|
|
|
|
|
{
|
|
|
|
|
|
/* On the i386 a denormalized extended precision float is
|
|
|
|
|
|
shifted down by one, effectively decreasing the exponent
|
|
|
|
|
|
bias by one. */
|
|
|
|
|
|
prec_bits -= 1;
|
|
|
|
|
|
num_bits += 1;
|
|
|
|
|
|
}
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
if (num_bits >= LITTLENUM_NUMBER_OF_BITS - exponent_bits)
|
|
|
|
|
|
{
|
|
|
|
|
|
/* Bigger than one littlenum */
|
|
|
|
|
|
num_bits -= (LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits;
|
|
|
|
|
|
*lp++ = word1;
|
|
|
|
|
|
if (num_bits + exponent_bits + 1 >= precision * LITTLENUM_NUMBER_OF_BITS)
|
|
|
|
|
|
{
|
|
|
|
|
|
/* Exponent overflow */
|
|
|
|
|
|
make_invalid_floating_point_number (words);
|
|
|
|
|
|
return (return_value);
|
|
|
|
|
|
}
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
if (precision == X_PRECISION && exponent_bits == 15)
|
|
|
|
|
|
*lp++ = 0;
|
|
|
|
|
|
#endif
|
|
|
|
|
|
while (num_bits >= LITTLENUM_NUMBER_OF_BITS)
|
|
|
|
|
|
{
|
|
|
|
|
|
num_bits -= LITTLENUM_NUMBER_OF_BITS;
|
|
|
|
|
|
*lp++ = 0;
|
|
|
|
|
|
}
|
|
|
|
|
|
if (num_bits)
|
|
|
|
|
|
*lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - (num_bits));
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
if (precision == X_PRECISION && exponent_bits == 15)
|
|
|
|
|
|
{
|
|
|
|
|
|
*lp++ = word1;
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
*lp++ = 0;
|
|
|
|
|
|
#endif
|
|
|
|
|
|
*lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - num_bits);
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
word1 |= next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) - (exponent_bits + num_bits));
|
|
|
|
|
|
*lp++ = word1;
|
|
|
|
|
|
}
|
|
|
|
|
|
}
|
|
|
|
|
|
while (lp < words_end)
|
|
|
|
|
|
*lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS);
|
|
|
|
|
|
|
|
|
|
|
|
/* Round the mantissa up, but don't change the number */
|
|
|
|
|
|
if (next_bits (1))
|
|
|
|
|
|
{
|
|
|
|
|
|
--lp;
|
|
|
|
|
|
if (prec_bits > LITTLENUM_NUMBER_OF_BITS)
|
|
|
|
|
|
{
|
|
|
|
|
|
int n = 0;
|
|
|
|
|
|
int tmp_bits;
|
|
|
|
|
|
|
|
|
|
|
|
n = 0;
|
|
|
|
|
|
tmp_bits = prec_bits;
|
|
|
|
|
|
while (tmp_bits > LITTLENUM_NUMBER_OF_BITS)
|
|
|
|
|
|
{
|
|
|
|
|
|
if (lp[n] != (LITTLENUM_TYPE) - 1)
|
|
|
|
|
|
break;
|
|
|
|
|
|
--n;
|
|
|
|
|
|
tmp_bits -= LITTLENUM_NUMBER_OF_BITS;
|
|
|
|
|
|
}
|
|
|
|
|
|
if (tmp_bits > LITTLENUM_NUMBER_OF_BITS || (lp[n] & mask[tmp_bits]) != mask[tmp_bits])
|
|
|
|
|
|
{
|
|
|
|
|
|
unsigned long carry;
|
|
|
|
|
|
|
|
|
|
|
|
for (carry = 1; carry && (lp >= words); lp--)
|
|
|
|
|
|
{
|
|
|
|
|
|
carry = *lp + carry;
|
|
|
|
|
|
*lp = carry;
|
|
|
|
|
|
carry >>= LITTLENUM_NUMBER_OF_BITS;
|
|
|
|
|
|
}
|
|
|
|
|
|
}
|
1998-09-06 22:57:45 +00:00
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
/* This is an overflow of the denormal numbers. We
|
|
|
|
|
|
need to forget what we have produced, and instead
|
|
|
|
|
|
generate the smallest normalized number. */
|
|
|
|
|
|
lp = words;
|
|
|
|
|
|
word1 = ((generic_floating_point_number.sign == '+')
|
|
|
|
|
|
? 0
|
|
|
|
|
|
: (1 << (LITTLENUM_NUMBER_OF_BITS - 1)));
|
|
|
|
|
|
word1 |= (1
|
|
|
|
|
|
<< ((LITTLENUM_NUMBER_OF_BITS - 1)
|
|
|
|
|
|
- exponent_bits));
|
|
|
|
|
|
*lp++ = word1;
|
|
|
|
|
|
while (lp < words_end)
|
|
|
|
|
|
*lp++ = 0;
|
|
|
|
|
|
}
|
1998-03-01 22:58:51 +00:00
|
|
|
|
}
|
|
|
|
|
|
else if ((*lp & mask[prec_bits]) != mask[prec_bits])
|
|
|
|
|
|
*lp += 1;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
return return_value;
|
|
|
|
|
|
}
|
1998-09-06 22:57:45 +00:00
|
|
|
|
else if ((unsigned long) exponent_4 >= mask[exponent_bits])
|
1998-03-01 22:58:51 +00:00
|
|
|
|
{
|
|
|
|
|
|
/*
|
|
|
|
|
|
* Exponent overflow. Lose immediately.
|
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
|
* We leave return_value alone: admit we read the
|
|
|
|
|
|
* number, but return a floating exception
|
|
|
|
|
|
* because we can't encode the number.
|
|
|
|
|
|
*/
|
|
|
|
|
|
make_invalid_floating_point_number (words);
|
|
|
|
|
|
return return_value;
|
|
|
|
|
|
}
|
|
|
|
|
|
else
|
|
|
|
|
|
{
|
|
|
|
|
|
word1 |= (exponent_4 << ((LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits))
|
|
|
|
|
|
| next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits);
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
*lp++ = word1;
|
|
|
|
|
|
|
|
|
|
|
|
/* X_PRECISION is special: on the 68k, it has 16 bits of zero in the
|
|
|
|
|
|
middle. Either way, it is then followed by a 1 bit. */
|
|
|
|
|
|
if (exponent_bits == 15 && precision == X_PRECISION)
|
|
|
|
|
|
{
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
*lp++ = 0;
|
|
|
|
|
|
#endif
|
|
|
|
|
|
*lp++ = (1 << (LITTLENUM_NUMBER_OF_BITS - 1)
|
|
|
|
|
|
| next_bits (LITTLENUM_NUMBER_OF_BITS - 1));
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* The rest of the words are just mantissa bits. */
|
|
|
|
|
|
while (lp < words_end)
|
|
|
|
|
|
*lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS);
|
|
|
|
|
|
|
|
|
|
|
|
if (next_bits (1))
|
|
|
|
|
|
{
|
|
|
|
|
|
unsigned long carry;
|
|
|
|
|
|
/*
|
|
|
|
|
|
* Since the NEXT bit is a 1, round UP the mantissa.
|
|
|
|
|
|
* The cunning design of these hidden-1 floats permits
|
|
|
|
|
|
* us to let the mantissa overflow into the exponent, and
|
|
|
|
|
|
* it 'does the right thing'. However, we lose if the
|
|
|
|
|
|
* highest-order bit of the lowest-order word flips.
|
|
|
|
|
|
* Is that clear?
|
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
/* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2)
|
|
|
|
|
|
Please allow at least 1 more bit in carry than is in a LITTLENUM.
|
|
|
|
|
|
We need that extra bit to hold a carry during a LITTLENUM carry
|
|
|
|
|
|
propagation. Another extra bit (kept 0) will assure us that we
|
|
|
|
|
|
don't get a sticky sign bit after shifting right, and that
|
|
|
|
|
|
permits us to propagate the carry without any masking of bits.
|
|
|
|
|
|
#endif */
|
|
|
|
|
|
for (carry = 1, lp--; carry && (lp >= words); lp--)
|
|
|
|
|
|
{
|
|
|
|
|
|
carry = *lp + carry;
|
|
|
|
|
|
*lp = carry;
|
|
|
|
|
|
carry >>= LITTLENUM_NUMBER_OF_BITS;
|
|
|
|
|
|
}
|
|
|
|
|
|
if (precision == X_PRECISION && exponent_bits == 15)
|
|
|
|
|
|
{
|
|
|
|
|
|
/* Extended precision numbers have an explicit integer bit
|
|
|
|
|
|
that we may have to restore. */
|
|
|
|
|
|
if (lp == words)
|
|
|
|
|
|
{
|
|
|
|
|
|
#ifdef TC_M68K
|
|
|
|
|
|
/* On the m68k there is a gap of 16 bits. We must
|
|
|
|
|
|
explicitly propagate the carry into the exponent. */
|
|
|
|
|
|
words[0] += words[1];
|
|
|
|
|
|
words[1] = 0;
|
|
|
|
|
|
lp++;
|
|
|
|
|
|
#endif
|
|
|
|
|
|
/* Put back the integer bit. */
|
|
|
|
|
|
lp[1] |= 1 << (LITTLENUM_NUMBER_OF_BITS - 1);
|
|
|
|
|
|
}
|
|
|
|
|
|
}
|
|
|
|
|
|
if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
|
|
|
|
|
|
{
|
|
|
|
|
|
/* We leave return_value alone: admit we read the
|
|
|
|
|
|
* number, but return a floating exception
|
|
|
|
|
|
* because we can't encode the number.
|
|
|
|
|
|
*/
|
|
|
|
|
|
*words &= ~(1 << (LITTLENUM_NUMBER_OF_BITS - 1));
|
|
|
|
|
|
/* make_invalid_floating_point_number (words); */
|
|
|
|
|
|
/* return return_value; */
|
|
|
|
|
|
}
|
|
|
|
|
|
}
|
|
|
|
|
|
return (return_value);
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
#if 0 /* unused */
|
|
|
|
|
|
/* This routine is a real kludge. Someone really should do it better,
|
|
|
|
|
|
but I'm too lazy, and I don't understand this stuff all too well
|
|
|
|
|
|
anyway. (JF) */
|
|
|
|
|
|
static void
|
|
|
|
|
|
int_to_gen (x)
|
|
|
|
|
|
long x;
|
|
|
|
|
|
{
|
|
|
|
|
|
char buf[20];
|
|
|
|
|
|
char *bufp;
|
|
|
|
|
|
|
|
|
|
|
|
sprintf (buf, "%ld", x);
|
|
|
|
|
|
bufp = &buf[0];
|
|
|
|
|
|
if (atof_generic (&bufp, ".", EXP_CHARS, &generic_floating_point_number))
|
|
|
|
|
|
as_bad ("Error converting number to floating point (Exponent overflow?)");
|
|
|
|
|
|
}
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
#ifdef TEST
|
|
|
|
|
|
char *
|
|
|
|
|
|
print_gen (gen)
|
|
|
|
|
|
FLONUM_TYPE *gen;
|
|
|
|
|
|
{
|
|
|
|
|
|
FLONUM_TYPE f;
|
|
|
|
|
|
LITTLENUM_TYPE arr[10];
|
|
|
|
|
|
double dv;
|
|
|
|
|
|
float fv;
|
|
|
|
|
|
static char sbuf[40];
|
|
|
|
|
|
|
|
|
|
|
|
if (gen)
|
|
|
|
|
|
{
|
|
|
|
|
|
f = generic_floating_point_number;
|
|
|
|
|
|
generic_floating_point_number = *gen;
|
|
|
|
|
|
}
|
|
|
|
|
|
gen_to_words (&arr[0], 4, 11);
|
|
|
|
|
|
memcpy (&dv, &arr[0], sizeof (double));
|
|
|
|
|
|
sprintf (sbuf, "%x %x %x %x %.14G ", arr[0], arr[1], arr[2], arr[3], dv);
|
|
|
|
|
|
gen_to_words (&arr[0], 2, 8);
|
|
|
|
|
|
memcpy (&fv, &arr[0], sizeof (float));
|
|
|
|
|
|
sprintf (sbuf + strlen (sbuf), "%x %x %.12g\n", arr[0], arr[1], fv);
|
|
|
|
|
|
|
|
|
|
|
|
if (gen)
|
|
|
|
|
|
{
|
|
|
|
|
|
generic_floating_point_number = f;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
return (sbuf);
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
/* end of atof-ieee.c */
|
