[deliverable/binutils-gdb.git] / gas / config / atof-tahoe.c


/* atof_tahoe.c - turn a string into a Tahoe floating point number
   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)

   I don't allow uppercase letters in the precision descrpitors. Ie 'f' and
   'd' are allowed but 'F' and 'D' aren't */

#include "as.h"

/* Precision in LittleNums. */
#define MAX_PRECISION (4)
#define D_PRECISION (4)
#define F_PRECISION (2)

/* Precision in chars. */
#define D_PRECISION_CHARS (8)
#define F_PRECISION_CHARS (4)

/* Length in LittleNums of guard bits. */
#define GUARD (2)

static const long int 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
};
\f

/* 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);

#else /* not __STDC__ */

int flonum_gen2tahoe ();

#endif /* not __STDC__ */


static int
next_bits (number_of_bits)
     int number_of_bits;
{
  int return_value;

  if (littlenum_pointer < littlenum_end)
    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;
      bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits;
      littlenum_pointer--;
      if (littlenum_pointer >= littlenum_end)
	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);
}

static void
make_invalid_floating_point_number (words)
     LITTLENUM_TYPE *words;
{
  *words = 0x8000;		/* Floating Reserved Operand Code */
}
\f
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. */
{
  int retval;			/* 0: OK. */

  retval = 0;
  switch (letter)
    {
    case 'f':
      *precisionP = F_PRECISION;
      *exponent_bitsP = 8;
      break;

    case 'd':
      *precisionP = D_PRECISION;
      *exponent_bitsP = 8;
      break;

    default:
      retval = 69;
      break;
    }
  return (retval);
}
\f
/***********************************************************************\
*									*
*	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. */
atof_tahoe (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. */
{
  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. */
  char *return_value;
  int precision;		/* Number of 16-bit words in the format. */
  long int exponent_bits;

  return_value = str;
  f.low = bits + MAX_PRECISION;
  f.high = NULL;
  f.leader = NULL;
  f.exponent = NULL;
  f.sign = '\0';

  if (what_kind_of_float (what_kind, &precision, &exponent_bits))
    {
      return_value = NULL;	/* We lost. */
      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. */
      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 */
	}
      else
	{
	  if (flonum_gen2tahoe (what_kind, &f, words))
	    {
	      return_value = NULL;
	    }
	}
    }
  return (return_value);
}
\f
/*
 * In: a flonum, a Tahoe floating point format.
 * Out: a Tahoe floating-point bit pattern.
 */

int				/* 0: OK. */
flonum_gen2tahoe (format_letter, f, words)
     char format_letter;	/* One of 'd' 'f'. */
     FLONUM_TYPE *f;
     LITTLENUM_TYPE *words;	/* Deliver answer here. */
{
  LITTLENUM_TYPE *lp;
  int precision;
  long int exponent_bits;
  int return_value;		/* 0 == OK. */

  return_value = what_kind_of_float (format_letter, &precision, &exponent_bits);
  if (return_value != 0)
    {
      make_invalid_floating_point_number (words);
    }
  else
    {
      if (f->low > f->leader)
	{
	  /* 0.0e0 seen. */
	  memset (words, '\0', sizeof (LITTLENUM_TYPE) * precision);
	}
      else
	{
	  long int exponent_1;
	  long int exponent_2;
	  long int exponent_3;
	  long int exponent_4;
	  int exponent_skippage;
	  LITTLENUM_TYPE word1;

	  /* 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.
	   */

	  bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
	  littlenum_pointer = f->leader;
	  littlenum_end = f->low;
	  /* 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. */
	  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));
	  /* Offset exponent. */

	  if (exponent_4 & ~mask[exponent_bits])
	    {
	      /*
	       * 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.
	       */
	    }
	  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))
		| ((f->sign == '+') ? 0 : 0x8000)
		| next_bits (15 - exponent_bits);
	      *lp++ = word1;

	      /* The rest of the words are just mantissa bits. */
	      for (; lp < words + precision; lp++)
		{
		  *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?
		   */

		  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
		    */
		  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)))
		    {
		      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.
		       */
		    }
		}		/* if (we needed to round up) */
	    }			/* if (exponent overflow) */
	}			/* if (0.0e0) */
    }				/* if (float_type was OK) */
  return (return_value);
}
\f
/*
 *		md_atof()
 *
 * 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.
 *	Address of where to build floating point literal.
 *		Assumed to be 'big enough'.
 *	Address of where to return size of literal (in chars).
 *
 * 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.
 */

char *
md_atof (what_statement_type, literalP, sizeP)
     char what_statement_type;
     char *literalP;
     int *sizeP;
{
  LITTLENUM_TYPE words[MAX_PRECISION];
  register char kind_of_float;
  register int number_of_chars;
  register LITTLENUM_TYPE *littlenum_pointer;

  switch (what_statement_type)
    {
    case 'f':			/* .ffloat */
    case 'd':			/* .dfloat */
      kind_of_float = what_statement_type;
      break;

    default:
      kind_of_float = 0;
      break;
    };

  if (kind_of_float)
    {
      register LITTLENUM_TYPE *limit;

      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.
       */
      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));
      limit = words + (number_of_chars / sizeof (LITTLENUM_TYPE));
      for (littlenum_pointer = words;
	   littlenum_pointer < limit;
	   littlenum_pointer++)
	{
	  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 */
Commit	Line	Data
88db8f81 KR	1
88db8f81 KR	2	/* atof_tahoe.c - turn a string into a Tahoe floating point number
48401fcf	3	Copyright (C) 1987, 1998 Free Software Foundation, Inc.
88db8f81 KR	4	*/
	5
	6	/* This is really a simplified version of atof_vax.c. I glommed it wholesale
	7	and then shaved it down. I don't even know how it works. (Don't you find
	8	my honesty refreshing? bowen@cs.Buffalo.EDU (Devon E Bowen)
	9
	10	I don't allow uppercase letters in the precision descrpitors. Ie 'f' and
	11	'd' are allowed but 'F' and 'D' aren't */
	12
	13	#include "as.h"
	14
	15	/* Precision in LittleNums. */
	16	#define MAX_PRECISION (4)
	17	#define D_PRECISION (4)
	18	#define F_PRECISION (2)
	19
	20	/* Precision in chars. */
	21	#define D_PRECISION_CHARS (8)
	22	#define F_PRECISION_CHARS (4)
	23
	24	/* Length in LittleNums of guard bits. */
	25	#define GUARD (2)
	26
	27	static const long int mask[] =
	28	{
	29	0x00000000,
	30	0x00000001,
	31	0x00000003,
	32	0x00000007,
	33	0x0000000f,
	34	0x0000001f,
	35	0x0000003f,
	36	0x0000007f,
	37	0x000000ff,
	38	0x000001ff,
	39	0x000003ff,
	40	0x000007ff,
	41	0x00000fff,
	42	0x00001fff,
	43	0x00003fff,
	44	0x00007fff,
	45	0x0000ffff,
	46	0x0001ffff,
	47	0x0003ffff,
	48	0x0007ffff,
	49	0x000fffff,
	50	0x001fffff,
	51	0x003fffff,
	52	0x007fffff,
	53	0x00ffffff,
	54	0x01ffffff,
	55	0x03ffffff,
	56	0x07ffffff,
	57	0x0fffffff,
	58	0x1fffffff,
	59	0x3fffffff,
	60	0x7fffffff,
	61	0xffffffff
	62	};
	63	\f
	64
	65	/* Shared between flonum_gen2tahoe and next_bits */
	66	static int bits_left_in_littlenum;
	67	static LITTLENUM_TYPE *littlenum_pointer;
68	static LITTLENUM_TYPE *littlenum_end;
69
70	#if __STDC__ == 1
71
72	int flonum_gen2tahoe (int format_letter, FLONUM_TYPE * f, LITTLENUM_TYPE * words);
73
74	#else /* not __STDC__ */
75
76	int flonum_gen2tahoe ();
77
78	#endif /* not __STDC__ */
79
80
81	static int
82	next_bits (number_of_bits)
83	int number_of_bits;
84	{
85	int return_value;
86
87	if (littlenum_pointer < littlenum_end)
88	return 0;
89	if (number_of_bits >= bits_left_in_littlenum)
90	{
91	return_value = mask[bits_left_in_littlenum] & *littlenum_pointer;
92	number_of_bits -= bits_left_in_littlenum;
93	return_value <<= number_of_bits;
94	bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits;
95	littlenum_pointer--;
96	if (littlenum_pointer >= littlenum_end)
97	return_value \|= ((*littlenum_pointer) >> (bits_left_in_littlenum)) &
98	mask[number_of_bits];
99	}
100	else
101	{
102	bits_left_in_littlenum -= number_of_bits;
103	return_value = mask[number_of_bits] &
104	((*littlenum_pointer) >> bits_left_in_littlenum);
105	}
106	return (return_value);
107	}
108
109	static void
110	make_invalid_floating_point_number (words)
111	LITTLENUM_TYPE *words;
112	{
113	words = 0x8000; / Floating Reserved Operand Code */
114	}
115	\f
116	static int /* 0 means letter is OK. */
117	what_kind_of_float (letter, precisionP, exponent_bitsP)
118	char letter; /* In: lowercase please. What kind of float? */
119	int precisionP; / Number of 16-bit words in the float. */
120	long int exponent_bitsP; / Number of exponent bits. */
121	{
122	int retval; /* 0: OK. */
123
124	retval = 0;
125	switch (letter)
126	{
127	case 'f':
128	*precisionP = F_PRECISION;
129	*exponent_bitsP = 8;
130	break;
131
132	case 'd':
133	*precisionP = D_PRECISION;
134	*exponent_bitsP = 8;
135	break;
136
137	default:
138	retval = 69;
139	break;
140	}
141	return (retval);
142	}
143	\f
144	/***********************************************************************\
145	* *
146	* Warning: this returns 16-bit LITTLENUMs, because that is *
147	* what the VAX thinks in. It is up to the caller to figure *
148	* out any alignment problems and to conspire for the bytes/word *
149	* to be emitted in the right order. Bigendians beware! *
150	* *
151	\***********************************************************************/
152
153	char * /* Return pointer past text consumed. */
154	atof_tahoe (str, what_kind, words)
155	char str; / Text to convert to binary. */
156	char what_kind; /* 'd', 'f', 'g', 'h' */
157	LITTLENUM_TYPE words; / Build the binary here. */
158	{
159	FLONUM_TYPE f;
160	LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD];
161	/* Extra bits for zeroed low-order bits. */
162	/* The 1st MAX_PRECISION are zeroed, */
163	/* the last contain flonum bits. */
164	char *return_value;
165	int precision; /* Number of 16-bit words in the format. */
166	long int exponent_bits;
167
168	return_value = str;
169	f.low = bits + MAX_PRECISION;
170	f.high = NULL;
171	f.leader = NULL;
172	f.exponent = NULL;
173	f.sign = '\0';
174
175	if (what_kind_of_float (what_kind, &precision, &exponent_bits))
176	{
177	return_value = NULL; /* We lost. */
178	make_invalid_floating_point_number (words);
179	}
180	if (return_value)
181	{
182	memset (bits, '\0', sizeof (LITTLENUM_TYPE) * MAX_PRECISION);
183
184	/* Use more LittleNums than seems */
185	/* necessary: the highest flonum may have */
186	/* 15 leading 0 bits, so could be useless. */
187	f.high = f.low + precision - 1 + GUARD;
188
189	if (atof_generic (&return_value, ".", "eE", &f))
190	{
191	make_invalid_floating_point_number (words);
192	return_value = NULL; /* we lost */
193	}
194	else
195	{
196	if (flonum_gen2tahoe (what_kind, &f, words))
197	{
198	return_value = NULL;
199	}
200	}
201	}
202	return (return_value);
203	}
204	\f
205	/*
206	* In: a flonum, a Tahoe floating point format.
207	* Out: a Tahoe floating-point bit pattern.
208	*/
209
210	int /* 0: OK. */
211	flonum_gen2tahoe (format_letter, f, words)
212	char format_letter; /* One of 'd' 'f'. */
213	FLONUM_TYPE *f;
214	LITTLENUM_TYPE words; / Deliver answer here. */
215	{
216	LITTLENUM_TYPE *lp;
217	int precision;
218	long int exponent_bits;
219	int return_value; /* 0 == OK. */
220
221	return_value = what_kind_of_float (format_letter, &precision, &exponent_bits);
222	if (return_value != 0)
223	{
224	make_invalid_floating_point_number (words);
225	}
226	else
227	{
228	if (f->low > f->leader)
229	{
230	/* 0.0e0 seen. */
231	memset (words, '\0', sizeof (LITTLENUM_TYPE) * precision);
232	}
233	else
234	{
235	long int exponent_1;
236	long int exponent_2;
237	long int exponent_3;
238	long int exponent_4;
239	int exponent_skippage;
240	LITTLENUM_TYPE word1;
241
242	/* JF: Deal with new Nan, +Inf and -Inf codes */
243	if (f->sign != '-' && f->sign != '+')
244	{
245	make_invalid_floating_point_number (words);
246	return return_value;
247	}
248	/*
249	* All tahoe floating_point formats have:
250	* Bit 15 is sign bit.
251	* Bits 14:n are excess-whatever exponent.
252	* Bits n-1:0 (if any) are most significant bits of fraction.
253	* Bits 15:0 of the next word are the next most significant bits.
254	* And so on for each other word.
255	*
256	* So we need: number of bits of exponent, number of bits of
257	* mantissa.
258	*/
259
260	bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
261	littlenum_pointer = f->leader;
262	littlenum_end = f->low;
263	/* Seek (and forget) 1st significant bit */
264	for (exponent_skippage = 0;
265	!next_bits (1);
266	exponent_skippage++)
267	{
268	}
269	exponent_1 = f->exponent + f->leader + 1 - f->low;
270	/* Radix LITTLENUM_RADIX, point just higher than f -> leader. */
271	exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS;
272	/* Radix 2. */
273	exponent_3 = exponent_2 - exponent_skippage;
274	/* Forget leading zeros, forget 1st bit. */
275	exponent_4 = exponent_3 + (1 << (exponent_bits - 1));
276	/* Offset exponent. */
277
278	if (exponent_4 & ~mask[exponent_bits])
279	{
280	/*
281	* Exponent overflow. Lose immediately.
282	*/
283
284	make_invalid_floating_point_number (words);
285
286	/*
287	* We leave return_value alone: admit we read the
288	* number, but return a floating exception
289	* because we can't encode the number.
290	*/
291	}
292	else
293	{
294	lp = words;
295
296	/* Word 1. Sign, exponent and perhaps high bits. */
297	/* Assume 2's complement integers. */
298	word1 = ((exponent_4 & mask[exponent_bits]) << (15 - exponent_bits))
299	\| ((f->sign == '+') ? 0 : 0x8000)
300	\| next_bits (15 - exponent_bits);
301	*lp++ = word1;
302
303	/* The rest of the words are just mantissa bits. */
304	for (; lp < words + precision; lp++)
305	{
306	*lp = next_bits (LITTLENUM_NUMBER_OF_BITS);
307	}
308
309	if (next_bits (1))
310	{
311	/*
312	* Since the NEXT bit is a 1, round UP the mantissa.
313	* The cunning design of these hidden-1 floats permits
314	* us to let the mantissa overflow into the exponent, and
315	* it 'does the right thing'. However, we lose if the
316	* highest-order bit of the lowest-order word flips.
317	* Is that clear?
318	*/
319
320	unsigned long int carry;
321
322	/*
323	#if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2)
324	Please allow at least 1 more bit in carry than is in a LITTLENUM.
325	We need that extra bit to hold a carry during a LITTLENUM carry
326	propagation. Another extra bit (kept 0) will assure us that we
327	don't get a sticky sign bit after shifting right, and that
328	permits us to propagate the carry without any masking of bits.
329	#endif
330	*/
331	for (carry = 1, lp--;
332	carry && (lp >= words);
333	lp--)
334	{
335	carry = *lp + carry;
336	*lp = carry;
337	carry >>= LITTLENUM_NUMBER_OF_BITS;
338	}
339
340	if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
341	{
342	make_invalid_floating_point_number (words);
343	/*
344	* We leave return_value alone: admit we read the
345	* number, but return a floating exception
346	* because we can't encode the number.
347	*/
348	}
349	} /* if (we needed to round up) */
350	} /* if (exponent overflow) */
351	} /* if (0.0e0) */
352	} /* if (float_type was OK) */
353	return (return_value);
354	}
355	\f
356	/*
357	* md_atof()
358	*
359	* In: input_line_pointer -> the 1st character of a floating-point
360	* number.
361	* 1 letter denoting the type of statement that wants a
362	* binary floating point number returned.
363	* Address of where to build floating point literal.
364	* Assumed to be 'big enough'.
365	* Address of where to return size of literal (in chars).
366	*
367	* Out: Input_line_pointer -> of next char after floating number.
43029a8f	368	* Error message, or 0.
88db8f81 KR	369	* Floating point literal.
	370	* Number of chars we used for the literal.
	371	*/
	372
	373	char *
	374	md_atof (what_statement_type, literalP, sizeP)
	375	char what_statement_type;
	376	char *literalP;
	377	int *sizeP;
	378	{
	379	LITTLENUM_TYPE words[MAX_PRECISION];
	380	register char kind_of_float;
	381	register int number_of_chars;
	382	register LITTLENUM_TYPE *littlenum_pointer;
	383
	384	switch (what_statement_type)
	385	{
	386	case 'f': /* .ffloat */
	387	case 'd': /* .dfloat */
	388	kind_of_float = what_statement_type;
	389	break;
	390
	391	default:
	392	kind_of_float = 0;
	393	break;
	394	};
	395
	396	if (kind_of_float)
	397	{
	398	register LITTLENUM_TYPE *limit;
	399
	400	input_line_pointer = atof_tahoe (input_line_pointer,
	401	kind_of_float,
	402	words);
	403	/*
	404	* The atof_tahoe() builds up 16-bit numbers.
	405	* Since the assembler may not be running on
	406	* a different-endian machine, be very careful about
	407	* converting words to chars.
	408	*/
	409	number_of_chars = (kind_of_float == 'f' ? F_PRECISION_CHARS :
	410	(kind_of_float == 'd' ? D_PRECISION_CHARS : 0));
	411	know (number_of_chars <= MAX_PRECISION * sizeof (LITTLENUM_TYPE));
	412	limit = words + (number_of_chars / sizeof (LITTLENUM_TYPE));
	413	for (littlenum_pointer = words;
	414	littlenum_pointer < limit;
	415	littlenum_pointer++)
	416	{
	417	md_number_to_chars (literalP, *littlenum_pointer,
	418	sizeof (LITTLENUM_TYPE));
	419	literalP += sizeof (LITTLENUM_TYPE);
	420	};
	421	}
	422	else
	423	{
	424	number_of_chars = 0;
	425	};
	426
	427	*sizeP = number_of_chars;
48401fcf	428	return kind_of_float ? 0 : _("Bad call to md_atof()");
43029a8f	429	}
88db8f81 KR	430
88db8f81 KR	431	/* atof_tahoe.c */