/* atof_ieee.c - turn a Flonum into an IEEE floating point number
- Copyright (C) 1987, 1992 Free Software Foundation, Inc.
-
+ Copyright (C) 1987, 92, 93, 94, 95, 96, 97, 98, 1999
+ 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. */
+ 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"
-#ifdef USG
-#define bzero(s,n) memset(s,0,n)
-#define bcopy(from,to,n) memcpy((to),(from),(n))
-#endif
+/* Flonums returned here. */
+extern FLONUM_TYPE generic_floating_point_number;
-extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */
+static int next_bits PARAMS ((int));
+static void unget_bits PARAMS ((int));
+static void make_invalid_floating_point_number PARAMS ((LITTLENUM_TYPE *));
-#ifndef NULL
-#define NULL (0)
-#endif
-
-extern char EXP_CHARS[];
+extern const char EXP_CHARS[];
/* Precision in LittleNums. */
-#define MAX_PRECISION (6)
+/* 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 (6)
-#define P_PRECISION (6)
+#define X_PRECISION (5)
+#define P_PRECISION (5)
/* 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 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,
};
\f
static LITTLENUM_TYPE *littlenum_pointer;
static int
- next_bits (number_of_bits)
-int number_of_bits;
+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);
+ 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];
}
- return(return_value);
+ }
+ 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;
+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;
+ 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;
+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;
+ 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;
}
\f
-/***********************************************************************\
+/************************************************************************\
* 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. */
+/* 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. */
{
- 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. */
-
- bzero(bits, 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);
+ /* 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;
+/* 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;
- bzero(&words[1], sizeof(LITTLENUM_TYPE) * (precision - 1));
- return(return_value);
+ 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;
}
-
- /* 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);
+ 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 */
}
- /*
- * 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);
+ 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;
}
-
- *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);
+ return (return_value);
+ }
+ else if (generic_floating_point_number.sign == 'N')
+ {
+ /* Negative INF */
+ if (precision == F_PRECISION)
+ {
+ words[0] = 0xff80;
+ words[1] = 0x0;
}
-
- /* 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;
+ 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 ((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; */
+ if (tmp_bits > LITTLENUM_NUMBER_OF_BITS
+ || (lp[n] & mask[tmp_bits]) != mask[tmp_bits]
+ || (prec_bits != (precision * LITTLENUM_NUMBER_OF_BITS
+ - exponent_bits - 1)
+#ifdef TC_I386
+ /* An extended precision float with only the integer
+ bit set would be invalid. That must be converted
+ to the smallest normalized number. */
+ && !(precision == X_PRECISION
+ && prec_bits == (precision * LITTLENUM_NUMBER_OF_BITS
+ - exponent_bits - 2))
+#endif
+ ))
+ {
+ unsigned long carry;
+
+ for (carry = 1; carry && (lp >= words); lp--)
+ {
+ carry = *lp + carry;
+ *lp = carry;
+ carry >>= LITTLENUM_NUMBER_OF_BITS;
+ }
}
+ 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;
+#ifdef TC_I386
+ /* Set the integer bit in the extended precision format.
+ This cannot happen on the m68k where the mantissa
+ just overflows into the integer bit above. */
+ if (precision == X_PRECISION)
+ *lp++ = 1 << (LITTLENUM_NUMBER_OF_BITS - 1);
+#endif
+ while (lp < words_end)
+ *lp++ = 0;
+ }
+ }
+ else
+ *lp += 1;
}
- return (return_value);
+
+ return return_value;
+ }
+ else if ((unsigned long) 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: 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);
}
-/* 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;
+#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?)");
+ 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;
+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);
- bcopy(&arr[0], &dv, 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);
- bcopy(&arr[0],&fv,sizeof(float));
- sprintf(sbuf + strlen(sbuf), "%x %x %.12g\n", arr[0], arr[1],
- fv);
-
- if (gen) {
- generic_floating_point_number = f;
- }
-
- return(sbuf);
+ 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 */
projects / external / binutils.git / blobdiff