mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2024-12-12 14:37:43 +00:00
355afbcd8b
Removed some unneeded files. obj-coff.c (obj_coff_endef): Use as_warn, not fprintf. tc-m68k.c (md_assemble): 68000+68881 is okay -- could be emulating.
577 lines
15 KiB
C
577 lines
15 KiB
C
/* atof_ieee.c - turn a Flonum into an IEEE floating point number
|
||
Copyright (C) 1987, 1992 Free Software Foundation, Inc.
|
||
|
||
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
|
||
|
||
#include "as.h"
|
||
|
||
extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */
|
||
|
||
#ifndef NULL
|
||
#define NULL (0)
|
||
#endif
|
||
|
||
extern const char EXP_CHARS[];
|
||
/* Precision in LittleNums. */
|
||
#define MAX_PRECISION (6)
|
||
#define F_PRECISION (2)
|
||
#define D_PRECISION (4)
|
||
#define X_PRECISION (6)
|
||
#define P_PRECISION (6)
|
||
|
||
/* Length in LittleNums of guard bits. */
|
||
#define GUARD (2)
|
||
|
||
static 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] = ((unsigned) -1) >> 1; /* Zero the leftmost bit */
|
||
words[1] = -1;
|
||
words[2] = -1;
|
||
words[3] = -1;
|
||
words[4] = -1;
|
||
words[5] = -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. */
|
||
|
||
char * /* Return pointer past text consumed. */
|
||
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. */
|
||
{
|
||
static LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD];
|
||
/* Extra bits for zeroed low-order bits. */
|
||
/* The 1st MAX_PRECISION are zeroed, */
|
||
/* the last contain flonum bits. */
|
||
char *return_value;
|
||
int precision; /* Number of 16-bit words in the format. */
|
||
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 = NULL;
|
||
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))
|
||
{
|
||
/* as_bad("Error converting floating point number (Exponent overflow?)"); */
|
||
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;
|
||
|
||
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', sizeof (LITTLENUM_TYPE) * (precision - 1));
|
||
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
|
||
{
|
||
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
|
||
{
|
||
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
|
||
{
|
||
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 < 1 && exponent_4 >= -62)
|
||
{
|
||
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);
|
||
if (precision == X_PRECISION && exponent_bits == 15)
|
||
prec_bits -= LITTLENUM_NUMBER_OF_BITS + 1;
|
||
|
||
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);
|
||
}
|
||
if (precision == X_PRECISION && exponent_bits == 15)
|
||
{
|
||
*lp++ = 0;
|
||
*lp++ = 0;
|
||
num_bits -= LITTLENUM_NUMBER_OF_BITS - 1;
|
||
}
|
||
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;
|
||
*lp++ = 0;
|
||
if (num_bits == LITTLENUM_NUMBER_OF_BITS)
|
||
{
|
||
*lp++ = 0;
|
||
*lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - 1);
|
||
}
|
||
else if (num_bits == LITTLENUM_NUMBER_OF_BITS - 1)
|
||
*lp++ = 0;
|
||
else
|
||
*lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - 1 - num_bits);
|
||
num_bits = 0;
|
||
}
|
||
else
|
||
{
|
||
word1 |= next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) - (exponent_bits + num_bits));
|
||
*lp++ = word1;
|
||
}
|
||
}
|
||
while (lp < words + precision)
|
||
*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;
|
||
}
|
||
}
|
||
}
|
||
else if ((*lp & mask[prec_bits]) != mask[prec_bits])
|
||
lp++;
|
||
}
|
||
|
||
return return_value;
|
||
}
|
||
else if (exponent_4 & ~mask[exponent_bits])
|
||
{
|
||
/*
|
||
* 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: it has 16 bits of zero in the middle,
|
||
followed by a 1 bit. */
|
||
if (exponent_bits == 15 && precision == X_PRECISION)
|
||
{
|
||
*lp++ = 0;
|
||
*lp++ = 1 << (LITTLENUM_NUMBER_OF_BITS) | next_bits (LITTLENUM_NUMBER_OF_BITS - 1);
|
||
}
|
||
|
||
/* The rest of the words are just mantissa bits. */
|
||
while (lp < words + precision)
|
||
*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 ((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);
|
||
}
|
||
|
||
/* 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)
|
||
*/
|
||
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?)");
|
||
}
|
||
|
||
#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 */
|