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2000-08-05 Kazu Hirata <kazu@hxi.com>

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* config/atof-ieee.c: Fix formatting.
	* config/atof-tahoe.c: Likewise.
This commit is contained in:
Kazu Hirata 2000-08-07 19:54:34 +00:00
parent dce618356b
commit 2d484c7fa2
3 changed files with 233 additions and 241 deletions
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5
gas/ChangeLog
View File

@ -1,3 +1,8 @@
2000-08-07 Kazu Hirata <kazu@hxi.com>
* config/atof-ieee.c: Fix formatting.
* config/atof-tahoe.c: Likewise.
2000-07-29 Marek Michalkiewicz <marekm@linux.org.pl>
* config/tc-avr.c: Use PARAMS macro in function declarations.

211
gas/config/atof-ieee.c
View File

@ -29,7 +29,7 @@ static void unget_bits PARAMS ((int));
static void make_invalid_floating_point_number PARAMS ((LITTLENUM_TYPE *));
extern const char EXP_CHARS[];
/* Precision in LittleNums. */
/* Precision in LittleNums. */
/* Don't count the gap in the m68k extended precision format. */
#define MAX_PRECISION (5)
#define F_PRECISION (2)
@ -37,7 +37,7 @@ extern const char EXP_CHARS[];
#define X_PRECISION (5)
#define P_PRECISION (5)
/* Length in LittleNums of guard bits. */
/* Length in LittleNums of guard bits. */
#define GUARD (2)
static const unsigned long mask[] =
@ -77,7 +77,6 @@ static const unsigned long mask[] =
0xffffffff,
};
static int bits_left_in_littlenum;
static int littlenums_left;
static LITTLENUM_TYPE *littlenum_pointer;
@ -100,18 +99,22 @@ next_bits (number_of_bits)
{
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];
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_value =
mask[number_of_bits] & (*littlenum_pointer >> bits_left_in_littlenum);
}
return (return_value);
return return_value;
}
/* Num had better be less than LITTLENUM_NUMBER_OF_BITS */
/* Num had better be less than LITTLENUM_NUMBER_OF_BITS. */
static void
unget_bits (num)
int num;
@ -124,7 +127,8 @@ unget_bits (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);
bits_left_in_littlenum =
num - (LITTLENUM_NUMBER_OF_BITS - bits_left_in_littlenum);
++littlenum_pointer;
++littlenums_left;
}
@ -137,7 +141,8 @@ 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 */
/* Zero the leftmost bit. */
words[0] = (LITTLENUM_TYPE) ((unsigned) -1) >> 1;
words[1] = (LITTLENUM_TYPE) -1;
words[2] = (LITTLENUM_TYPE) -1;
words[3] = (LITTLENUM_TYPE) -1;
@ -145,29 +150,27 @@ make_invalid_floating_point_number (words)
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! *
* *
\************************************************************************/
/* 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. */
/* Returns pointer past text consumed. */
char *
atof_ieee (str, what_kind, words)
char *str; /* Text to convert to binary. */
int what_kind; /* 'd', 'f', 'g', 'h' */
LITTLENUM_TYPE *words; /* Build the binary here. */
char *str; /* Text to convert to binary. */
int 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. */
/* 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. */
/* Number of 16-bit words in the format. */
int precision;
long exponent_bits;
FLONUM_TYPE save_gen_flonum;
@ -186,7 +189,7 @@ atof_ieee (str, what_kind, words)
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. */
have 15 leading 0 bits, so could be useless. */
memset (bits, '\0', sizeof (LITTLENUM_TYPE) * MAX_PRECISION);
@ -247,6 +250,7 @@ atof_ieee (str, what_kind, words)
}
/* Turn generic_floating_point_number into a real float/double/extended. */
int
gen_to_words (words, precision, exponent_bits)
LITTLENUM_TYPE *words;
@ -274,17 +278,17 @@ gen_to_words (words, precision, exponent_bits)
if (generic_floating_point_number.low > generic_floating_point_number.leader)
{
/* 0.0e0 seen. */
/* 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);
return return_value;
}
/* NaN: Do the right thing */
/* NaN: Do the right thing. */
if (generic_floating_point_number.sign == 0)
{
if (precision == F_PRECISION)
@ -301,17 +305,17 @@ gen_to_words (words, precision, exponent_bits)
words[3] = 0xffff;
words[4] = 0xffff;
words[5] = 0xffff;
#else /* ! TC_M68K */
#else /* ! TC_M68K */
#ifdef TC_I386
words[0] = 0xffff;
words[1] = 0xc000;
words[2] = 0;
words[3] = 0;
words[4] = 0;
#else /* ! TC_I386 */
#else /* ! TC_I386 */
abort ();
#endif /* ! TC_I386 */
#endif /* ! TC_M68K */
#endif /* ! TC_I386 */
#endif /* ! TC_M68K */
}
else
{
@ -324,7 +328,7 @@ gen_to_words (words, precision, exponent_bits)
}
else if (generic_floating_point_number.sign == 'P')
{
/* +INF: Do the right thing */
/* +INF: Do the right thing. */
if (precision == F_PRECISION)
{
words[0] = 0x7f80;
@ -339,17 +343,17 @@ gen_to_words (words, precision, exponent_bits)
words[3] = 0;
words[4] = 0;
words[5] = 0;
#else /* ! TC_M68K */
#else /* ! TC_M68K */
#ifdef TC_I386
words[0] = 0x7fff;
words[1] = 0x8000;
words[2] = 0;
words[3] = 0;
words[4] = 0;
#else /* ! TC_I386 */
#else /* ! TC_I386 */
abort ();
#endif /* ! TC_I386 */
#endif /* ! TC_M68K */
#endif /* ! TC_I386 */
#endif /* ! TC_M68K */
}
else
{
@ -358,11 +362,11 @@ gen_to_words (words, precision, exponent_bits)
words[2] = 0;
words[3] = 0;
}
return (return_value);
return return_value;
}
else if (generic_floating_point_number.sign == 'N')
{
/* Negative INF */
/* Negative INF. */
if (precision == F_PRECISION)
{
words[0] = 0xff80;
@ -377,17 +381,17 @@ gen_to_words (words, precision, exponent_bits)
words[3] = 0;
words[4] = 0;
words[5] = 0;
#else /* ! TC_M68K */
#else /* ! TC_M68K */
#ifdef TC_I386
words[0] = 0xffff;
words[1] = 0x8000;
words[2] = 0;
words[3] = 0;
words[4] = 0;
#else /* ! TC_I386 */
#else /* ! TC_I386 */
abort ();
#endif /* ! TC_I386 */
#endif /* ! TC_M68K */
#endif /* ! TC_I386 */
#endif /* ! TC_M68K */
}
else
{
@ -396,46 +400,49 @@ gen_to_words (words, precision, exponent_bits)
words[2] = 0x0;
words[3] = 0x0;
}
return (return_value);
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.
*/
/* 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 */
/* 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. */
/* 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. */
/* 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. */
/* Assume 2's complement integers. */
if (exponent_4 <= 0)
{
int prec_bits;
@ -443,7 +450,8 @@ gen_to_words (words, precision, exponent_bits)
unget_bits (1);
num_bits = -exponent_4;
prec_bits = LITTLENUM_NUMBER_OF_BITS * precision - (exponent_bits + 1 + num_bits);
prec_bits =
LITTLENUM_NUMBER_OF_BITS * precision - (exponent_bits + 1 + num_bits);
#ifdef TC_I386
if (precision == X_PRECISION && exponent_bits == 15)
{
@ -457,14 +465,15 @@ gen_to_words (words, precision, exponent_bits)
if (num_bits >= LITTLENUM_NUMBER_OF_BITS - exponent_bits)
{
/* Bigger than one littlenum */
/* 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)
if (num_bits + exponent_bits + 1
> precision * LITTLENUM_NUMBER_OF_BITS)
{
/* Exponent overflow */
/* Exponent overflow. */
make_invalid_floating_point_number (words);
return (return_value);
return return_value;
}
#ifdef TC_M68K
if (precision == X_PRECISION && exponent_bits == 15)
@ -490,14 +499,15 @@ gen_to_words (words, precision, exponent_bits)
}
else
{
word1 |= next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) - (exponent_bits + num_bits));
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 */
/* Round the mantissa up, but don't change the number. */
if (next_bits (1))
{
--lp;
@ -570,15 +580,11 @@ gen_to_words (words, precision, exponent_bits)
}
else if ((unsigned long) exponent_4 >= mask[exponent_bits])
{
/*
* Exponent overflow. Lose immediately.
*/
/* 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.
*/
/* 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;
}
@ -591,7 +597,7 @@ gen_to_words (words, precision, 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. */
middle. Either way, it is then followed by a 1 bit. */
if (exponent_bits == 15 && precision == X_PRECISION)
{
#ifdef TC_M68K
@ -601,21 +607,19 @@ gen_to_words (words, precision, exponent_bits)
| next_bits (LITTLENUM_NUMBER_OF_BITS - 1));
}
/* The rest of the words are just mantissa bits. */
/* 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?
*/
/* 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.
@ -640,33 +644,36 @@ gen_to_words (words, precision, exponent_bits)
{
#ifdef TC_M68K
/* On the m68k there is a gap of 16 bits. We must
explicitly propagate the carry into the exponent. */
explicitly propagate the carry into the exponent. */
words[0] += words[1];
words[1] = 0;
lp++;
#endif
/* Put back the integer bit. */
/* 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.
*/
/* 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; */
#if 0
make_invalid_floating_point_number (words);
return return_value;
#endif
}
}
return (return_value);
return return_value;
}
#if 0 /* unused */
#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;
@ -705,13 +712,9 @@ print_gen (gen)
sprintf (sbuf + strlen (sbuf), "%x %x %.12g\n", arr[0], arr[1], fv);
if (gen)
{
generic_floating_point_number = f;
}
generic_floating_point_number = f;
return (sbuf);
}
#endif
/* end of atof-ieee.c */

258
gas/config/atof-tahoe.c
View File

@ -1,27 +1,25 @@
/* atof_tahoe.c - turn a string into a Tahoe floating point number
Copyright (C) 1987, 1998 Free Software Foundation, Inc.
*/
Copyright (C) 1987, 1998 Free Software Foundation, Inc. */
/* This is really a simplified version of atof_vax.c. I glommed it wholesale
and then shaved it down. I don't even know how it works. (Don't you find
my honesty refreshing? bowen@cs.Buffalo.EDU (Devon E Bowen)
my honesty refreshing? Devon E Bowen <bowen@cs.buffalo.edu>
I don't allow uppercase letters in the precision descrpitors. Ie 'f' and
'd' are allowed but 'F' and 'D' aren't */
I don't allow uppercase letters in the precision descrpitors.
i.e. 'f' and 'd' are allowed but 'F' and 'D' aren't. */
#include "as.h"
/* Precision in LittleNums. */
/* Precision in LittleNums. */
#define MAX_PRECISION (4)
#define D_PRECISION (4)
#define F_PRECISION (2)
/* Precision in chars. */
/* Precision in chars. */
#define D_PRECISION_CHARS (8)
#define F_PRECISION_CHARS (4)
/* Length in LittleNums of guard bits. */
/* Length in LittleNums of guard bits. */
#define GUARD (2)
static const long int mask[] =
@ -61,22 +59,21 @@ static const long int mask[] =
0xffffffff
};
/* Shared between flonum_gen2tahoe and next_bits */
/* Shared between flonum_gen2tahoe and next_bits. */
static int bits_left_in_littlenum;
static LITTLENUM_TYPE *littlenum_pointer;
static LITTLENUM_TYPE *littlenum_end;
#if __STDC__ == 1
int flonum_gen2tahoe (int format_letter, FLONUM_TYPE * f, LITTLENUM_TYPE * words);
int flonum_gen2tahoe (int format_letter, FLONUM_TYPE * f,
LITTLENUM_TYPE * words);
#else /* not __STDC__ */
#else /* not __STDC__ */
int flonum_gen2tahoe ();
#endif /* not __STDC__ */
#endif /* not __STDC__ */
static int
next_bits (number_of_bits)
@ -103,23 +100,29 @@ next_bits (number_of_bits)
return_value = mask[number_of_bits] &
((*littlenum_pointer) >> bits_left_in_littlenum);
}
return (return_value);
return return_value;
}
static void
make_invalid_floating_point_number (words)
LITTLENUM_TYPE *words;
{
*words = 0x8000; /* Floating Reserved Operand Code */
/* Floating Reserved Operand Code. */
*words = 0x8000;
}
static int /* 0 means letter is OK. */
static int /* 0 means letter is OK. */
what_kind_of_float (letter, precisionP, exponent_bitsP)
char letter; /* In: lowercase please. What kind of float? */
int *precisionP; /* Number of 16-bit words in the float. */
long int *exponent_bitsP; /* Number of exponent bits. */
/* In: lowercase please. What kind of float? */
char letter;
/* Number of 16-bit words in the float. */
int *precisionP;
/* Number of exponent bits. */
long int *exponent_bitsP;
{
int retval; /* 0: OK. */
int retval; /* 0: OK. */
retval = 0;
switch (letter)
@ -141,28 +144,23 @@ what_kind_of_float (letter, precisionP, exponent_bitsP)
return (retval);
}
/***********************************************************************\
* *
* Warning: this returns 16-bit LITTLENUMs, because that is *
* what the VAX thinks in. 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! *
* *
\***********************************************************************/
/* Warning: This returns 16-bit LITTLENUMs, because that is what the
VAX thinks in. 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! */
char * /* Return pointer past text consumed. */
char * /* Return pointer past text consumed. */
atof_tahoe (str, what_kind, words)
char *str; /* Text to convert to binary. */
char *str; /* Text to convert to binary. */
char what_kind; /* 'd', 'f', 'g', 'h' */
LITTLENUM_TYPE *words; /* Build the binary here. */
LITTLENUM_TYPE *words; /* Build the binary here. */
{
FLONUM_TYPE f;
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. */
/* 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. */
int precision; /* Number of 16-bit words in the format. */
long int exponent_bits;
return_value = str;
@ -174,51 +172,50 @@ atof_tahoe (str, what_kind, words)
if (what_kind_of_float (what_kind, &precision, &exponent_bits))
{
return_value = NULL; /* We lost. */
/* We lost. */
return_value = NULL;
make_invalid_floating_point_number (words);
}
if (return_value)
{
memset (bits, '\0', sizeof (LITTLENUM_TYPE) * MAX_PRECISION);
/* Use more LittleNums than seems */
/* necessary: the highest flonum may have */
/* 15 leading 0 bits, so could be useless. */
/* Use more LittleNums than seems necessary:
the highest flonum may have 15 leading 0 bits, so could be
useless. */
f.high = f.low + precision - 1 + GUARD;
if (atof_generic (&return_value, ".", "eE", &f))
{
make_invalid_floating_point_number (words);
return_value = NULL; /* we lost */
/* We lost. */
return_value = NULL;
}
else
{
if (flonum_gen2tahoe (what_kind, &f, words))
{
return_value = NULL;
}
return_value = NULL;
}
}
return (return_value);
return return_value;
}
/*
* In: a flonum, a Tahoe floating point format.
* Out: a Tahoe floating-point bit pattern.
*/
/* In: a flonum, a Tahoe floating point format.
Out: a Tahoe floating-point bit pattern. */
int /* 0: OK. */
int /* 0: OK. */
flonum_gen2tahoe (format_letter, f, words)
char format_letter; /* One of 'd' 'f'. */
char format_letter; /* One of 'd' 'f'. */
FLONUM_TYPE *f;
LITTLENUM_TYPE *words; /* Deliver answer here. */
LITTLENUM_TYPE *words; /* Deliver answer here. */
{
LITTLENUM_TYPE *lp;
int precision;
long int exponent_bits;
int return_value; /* 0 == OK. */
int return_value; /* 0 == OK. */
return_value = what_kind_of_float (format_letter, &precision, &exponent_bits);
return_value =
what_kind_of_float (format_letter, &precision, &exponent_bits);
if (return_value != 0)
{
make_invalid_floating_point_number (words);
@ -227,7 +224,7 @@ flonum_gen2tahoe (format_letter, f, words)
{
if (f->low > f->leader)
{
/* 0.0e0 seen. */
/* 0.0e0 seen. */
memset (words, '\0', sizeof (LITTLENUM_TYPE) * precision);
}
else
@ -239,95 +236,91 @@ flonum_gen2tahoe (format_letter, f, words)
int exponent_skippage;
LITTLENUM_TYPE word1;
/* JF: Deal with new Nan, +Inf and -Inf codes */
/* JF: Deal with new Nan, +Inf and -Inf codes. */
if (f->sign != '-' && f->sign != '+')
{
make_invalid_floating_point_number (words);
return return_value;
}
/*
* All tahoe floating_point formats 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 are the next most significant bits.
* And so on for each other word.
*
* So we need: number of bits of exponent, number of bits of
* mantissa.
*/
/* All tahoe floating_point formats 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 are the next most significant bits.
And so on for each other word.
So we need: number of bits of exponent, number of bits of
mantissa. */
bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
littlenum_pointer = f->leader;
littlenum_end = f->low;
/* Seek (and forget) 1st significant bit */
/* Seek (and forget) 1st significant bit. */
for (exponent_skippage = 0;
!next_bits (1);
exponent_skippage++)
{
}
;
exponent_1 = f->exponent + f->leader + 1 - f->low;
/* Radix LITTLENUM_RADIX, point just higher than f -> leader. */
/* Radix LITTLENUM_RADIX, point just higher than f -> leader. */
exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS;
/* Radix 2. */
/* Radix 2. */
exponent_3 = exponent_2 - exponent_skippage;
/* Forget leading zeros, forget 1st bit. */
/* Forget leading zeros, forget 1st bit. */
exponent_4 = exponent_3 + (1 << (exponent_bits - 1));
/* Offset exponent. */
/* Offset exponent. */
if (exponent_4 & ~mask[exponent_bits])
{
/*
* Exponent overflow. Lose immediately.
*/
/* Exponent overflow. Lose immediately. */
make_invalid_floating_point_number (words);
/*
* We leave return_value alone: admit we read the
* number, but return a floating exception
* because we can't encode the number.
*/
/* We leave return_value alone: admit we read the
number, but return a floating exception because we
can't encode the number. */
}
else
{
lp = words;
/* Word 1. Sign, exponent and perhaps high bits. */
/* Assume 2's complement integers. */
word1 = ((exponent_4 & mask[exponent_bits]) << (15 - exponent_bits))
/* Word 1. Sign, exponent and perhaps high bits. */
/* Assume 2's complement integers. */
word1 = ((exponent_4 & mask[exponent_bits])
<< (15 - exponent_bits))
| ((f->sign == '+') ? 0 : 0x8000)
| next_bits (15 - exponent_bits);
*lp++ = word1;
/* The rest of the words are just mantissa bits. */
/* The rest of the words are just mantissa bits. */
for (; lp < words + precision; lp++)
{
*lp = next_bits (LITTLENUM_NUMBER_OF_BITS);
}
*lp = next_bits (LITTLENUM_NUMBER_OF_BITS);
if (next_bits (1))
{
/*
* 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?
*/
/* 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? */
unsigned long int carry;
/*
#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
*/
/* #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--)
@ -337,26 +330,22 @@ flonum_gen2tahoe (format_letter, f, words)
carry >>= LITTLENUM_NUMBER_OF_BITS;
}
if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
if ((word1 ^ *words)
& (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
{
make_invalid_floating_point_number (words);
/*
* We leave return_value alone: admit we read the
* number, but return a floating exception
* because we can't encode the number.
*/
/* We leave return_value alone: admit we read
the number, but return a floating exception
because we can't encode the number. */
}
} /* if (we needed to round up) */
} /* if (exponent overflow) */
} /* if (0.0e0) */
} /* if (float_type was OK) */
return (return_value);
} /* if (we needed to round up) */
} /* if (exponent overflow) */
} /* if (0.0e0) */
} /* if (float_type was OK) */
return return_value;
}
/*
* md_atof()
*
* In: input_line_pointer -> the 1st character of a floating-point
/* In: input_line_pointer -> the 1st character of a floating-point
* number.
* 1 letter denoting the type of statement that wants a
* binary floating point number returned.
@ -367,8 +356,7 @@ flonum_gen2tahoe (format_letter, f, words)
* Out: Input_line_pointer -> of next char after floating number.
* Error message, or 0.
* Floating point literal.
* Number of chars we used for the literal.
*/
* Number of chars we used for the literal. */
char *
md_atof (what_statement_type, literalP, sizeP)
@ -383,15 +371,15 @@ md_atof (what_statement_type, literalP, sizeP)
switch (what_statement_type)
{
case 'f': /* .ffloat */
case 'd': /* .dfloat */
case 'f': /* .ffloat */
case 'd': /* .dfloat */
kind_of_float = what_statement_type;
break;
default:
kind_of_float = 0;
break;
};
}
if (kind_of_float)
{
@ -400,12 +388,10 @@ md_atof (what_statement_type, literalP, sizeP)
input_line_pointer = atof_tahoe (input_line_pointer,
kind_of_float,
words);
/*
* The atof_tahoe() builds up 16-bit numbers.
* Since the assembler may not be running on
* a different-endian machine, be very careful about
* converting words to chars.
*/
/* The atof_tahoe() builds up 16-bit numbers.
Since the assembler may not be running on
a different-endian machine, be very careful about
converting words to chars. */
number_of_chars = (kind_of_float == 'f' ? F_PRECISION_CHARS :
(kind_of_float == 'd' ? D_PRECISION_CHARS : 0));
know (number_of_chars <= MAX_PRECISION * sizeof (LITTLENUM_TYPE));
@ -417,15 +403,13 @@ md_atof (what_statement_type, literalP, sizeP)
md_number_to_chars (literalP, *littlenum_pointer,
sizeof (LITTLENUM_TYPE));
literalP += sizeof (LITTLENUM_TYPE);
};
}
}
else
{
number_of_chars = 0;
};
}
*sizeP = number_of_chars;
return kind_of_float ? 0 : _("Bad call to md_atof()");
}
/* atof_tahoe.c */