/* IEEE floating point support routines, for GDB, the GNU Debugger.
- Copyright (C) 1991, 1994, 1999, 2000 Free Software Foundation, Inc.
+ Copyright 1991, 1994, 1999, 2000, 2003, 2005, 2006
+ Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
+/* This is needed to pick up the NAN macro on some systems. */
+#define _GNU_SOURCE
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <math.h>
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+/* On some platforms, <float.h> provides DBL_QNAN. */
+#ifdef STDC_HEADERS
+#include <float.h>
+#endif
+
+#include "ansidecl.h"
+#include "libiberty.h"
#include "floatformat.h"
-#include <math.h> /* ldexp */
-#ifdef __STDC__
-#include <stddef.h>
-extern void *memcpy (void *s1, const void *s2, size_t n);
-extern void *memset (void *s, int c, size_t n);
+
+#ifndef INFINITY
+#ifdef HUGE_VAL
+#define INFINITY HUGE_VAL
+#else
+#define INFINITY (1.0 / 0.0)
+#endif
+#endif
+
+#ifndef NAN
+#ifdef DBL_QNAN
+#define NAN DBL_QNAN
#else
-extern char *memcpy ();
-extern char *memset ();
+#define NAN (0.0 / 0.0)
#endif
+#endif
+
+static int mant_bits_set (const struct floatformat *, const unsigned char *);
+static unsigned long get_field (const unsigned char *,
+ enum floatformat_byteorders,
+ unsigned int,
+ unsigned int,
+ unsigned int);
+static int floatformat_always_valid (const struct floatformat *fmt,
+ const void *from);
+
+static int
+floatformat_always_valid (const struct floatformat *fmt ATTRIBUTE_UNUSED,
+ const void *from ATTRIBUTE_UNUSED)
+{
+ return 1;
+}
/* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not
going to bother with trying to muck around with whether it is defined in
{
floatformat_big, 32, 0, 1, 8, 127, 255, 9, 23,
floatformat_intbit_no,
- "floatformat_ieee_single_big"
+ "floatformat_ieee_single_big",
+ floatformat_always_valid,
+ NULL
};
const struct floatformat floatformat_ieee_single_little =
{
floatformat_little, 32, 0, 1, 8, 127, 255, 9, 23,
floatformat_intbit_no,
- "floatformat_ieee_single_little"
+ "floatformat_ieee_single_little",
+ floatformat_always_valid,
+ NULL
};
const struct floatformat floatformat_ieee_double_big =
{
floatformat_big, 64, 0, 1, 11, 1023, 2047, 12, 52,
floatformat_intbit_no,
- "floatformat_ieee_double_big"
+ "floatformat_ieee_double_big",
+ floatformat_always_valid,
+ NULL
};
const struct floatformat floatformat_ieee_double_little =
{
floatformat_little, 64, 0, 1, 11, 1023, 2047, 12, 52,
floatformat_intbit_no,
- "floatformat_ieee_double_little"
+ "floatformat_ieee_double_little",
+ floatformat_always_valid,
+ NULL
};
/* floatformat for IEEE double, little endian byte order, with big endian word
{
floatformat_littlebyte_bigword, 64, 0, 1, 11, 1023, 2047, 12, 52,
floatformat_intbit_no,
- "floatformat_ieee_double_littlebyte_bigword"
+ "floatformat_ieee_double_littlebyte_bigword",
+ floatformat_always_valid,
+ NULL
+};
+
+/* floatformat for VAX. Not quite IEEE, but close enough. */
+
+const struct floatformat floatformat_vax_f =
+{
+ floatformat_vax, 32, 0, 1, 8, 129, 0, 9, 23,
+ floatformat_intbit_no,
+ "floatformat_vax_f",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_vax_d =
+{
+ floatformat_vax, 64, 0, 1, 8, 129, 0, 9, 55,
+ floatformat_intbit_no,
+ "floatformat_vax_d",
+ floatformat_always_valid,
+ NULL
};
+const struct floatformat floatformat_vax_g =
+{
+ floatformat_vax, 64, 0, 1, 11, 1025, 0, 12, 52,
+ floatformat_intbit_no,
+ "floatformat_vax_g",
+ floatformat_always_valid,
+ NULL
+};
+
+static int floatformat_i387_ext_is_valid (const struct floatformat *fmt,
+ const void *from);
+
+static int
+floatformat_i387_ext_is_valid (const struct floatformat *fmt, const void *from)
+{
+ /* In the i387 double-extended format, if the exponent is all ones,
+ then the integer bit must be set. If the exponent is neither 0
+ nor ~0, the intbit must also be set. Only if the exponent is
+ zero can it be zero, and then it must be zero. */
+ unsigned long exponent, int_bit;
+ const unsigned char *ufrom = (const unsigned char *) from;
+
+ exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
+ fmt->exp_start, fmt->exp_len);
+ int_bit = get_field (ufrom, fmt->byteorder, fmt->totalsize,
+ fmt->man_start, 1);
+
+ if ((exponent == 0) != (int_bit == 0))
+ return 0;
+ else
+ return 1;
+}
const struct floatformat floatformat_i387_ext =
{
floatformat_little, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
floatformat_intbit_yes,
- "floatformat_i387_ext"
+ "floatformat_i387_ext",
+ floatformat_i387_ext_is_valid,
+ NULL
};
const struct floatformat floatformat_m68881_ext =
{
/* Note that the bits from 16 to 31 are unused. */
floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64,
floatformat_intbit_yes,
- "floatformat_m68881_ext"
+ "floatformat_m68881_ext",
+ floatformat_always_valid,
+ NULL
};
const struct floatformat floatformat_i960_ext =
{
/* Note that the bits from 0 to 15 are unused. */
floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64,
floatformat_intbit_yes,
- "floatformat_i960_ext"
+ "floatformat_i960_ext",
+ floatformat_always_valid,
+ NULL
};
const struct floatformat floatformat_m88110_ext =
{
-#ifdef HARRIS_FLOAT_FORMAT
+ floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
+ floatformat_intbit_yes,
+ "floatformat_m88110_ext",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_m88110_harris_ext =
+{
/* Harris uses raw format 128 bytes long, but the number is just an ieee
double, and the last 64 bits are wasted. */
floatformat_big,128, 0, 1, 11, 0x3ff, 0x7ff, 12, 52,
floatformat_intbit_no,
- "floatformat_m88110_ext(harris)"
-#else
- floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
- floatformat_intbit_yes,
- "floatformat_m88110_ext"
-#endif /* HARRIS_FLOAT_FORMAT */
+ "floatformat_m88110_ext_harris",
+ floatformat_always_valid,
+ NULL
};
-const struct floatformat floatformat_arm_ext =
+const struct floatformat floatformat_arm_ext_big =
{
/* Bits 1 to 16 are unused. */
floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
floatformat_intbit_yes,
- "floatformat_arm_ext"
+ "floatformat_arm_ext_big",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_arm_ext_littlebyte_bigword =
+{
+ /* Bits 1 to 16 are unused. */
+ floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
+ floatformat_intbit_yes,
+ "floatformat_arm_ext_littlebyte_bigword",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_ia64_spill_big =
+{
+ floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
+ floatformat_intbit_yes,
+ "floatformat_ia64_spill_big",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_ia64_spill_little =
+{
+ floatformat_little, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
+ floatformat_intbit_yes,
+ "floatformat_ia64_spill_little",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_ia64_quad_big =
+{
+ floatformat_big, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
+ floatformat_intbit_no,
+ "floatformat_ia64_quad_big",
+ floatformat_always_valid,
+ NULL
+};
+const struct floatformat floatformat_ia64_quad_little =
+{
+ floatformat_little, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
+ floatformat_intbit_no,
+ "floatformat_ia64_quad_little",
+ floatformat_always_valid,
+ NULL
+};
+
+static int
+floatformat_ibm_long_double_is_valid (const struct floatformat *fmt,
+ const void *from)
+{
+ const unsigned char *ufrom = (const unsigned char *) from;
+ const struct floatformat *hfmt = fmt->split_half;
+ long top_exp, bot_exp;
+ int top_nan = 0;
+
+ top_exp = get_field (ufrom, hfmt->byteorder, hfmt->totalsize,
+ hfmt->exp_start, hfmt->exp_len);
+ bot_exp = get_field (ufrom + 8, hfmt->byteorder, hfmt->totalsize,
+ hfmt->exp_start, hfmt->exp_len);
+
+ if ((unsigned long) top_exp == hfmt->exp_nan)
+ top_nan = mant_bits_set (hfmt, ufrom);
+
+ /* A NaN is valid with any low part. */
+ if (top_nan)
+ return 1;
+
+ /* An infinity, zero or denormal requires low part 0 (positive or
+ negative). */
+ if ((unsigned long) top_exp == hfmt->exp_nan || top_exp == 0)
+ {
+ if (bot_exp != 0)
+ return 0;
+
+ return !mant_bits_set (hfmt, ufrom + 8);
+ }
+
+ /* The top part is now a finite normal value. The long double value
+ is the sum of the two parts, and the top part must equal the
+ result of rounding the long double value to nearest double. Thus
+ the bottom part must be <= 0.5ulp of the top part in absolute
+ value, and if it is < 0.5ulp then the long double is definitely
+ valid. */
+ if (bot_exp < top_exp - 53)
+ return 1;
+ if (bot_exp > top_exp - 53 && bot_exp != 0)
+ return 0;
+ if (bot_exp == 0)
+ {
+ /* The bottom part is 0 or denormal. Determine which, and if
+ denormal the first two set bits. */
+ int first_bit = -1, second_bit = -1, cur_bit;
+ for (cur_bit = 0; (unsigned int) cur_bit < hfmt->man_len; cur_bit++)
+ if (get_field (ufrom + 8, hfmt->byteorder, hfmt->totalsize,
+ hfmt->man_start + cur_bit, 1))
+ {
+ if (first_bit == -1)
+ first_bit = cur_bit;
+ else
+ {
+ second_bit = cur_bit;
+ break;
+ }
+ }
+ /* Bottom part 0 is OK. */
+ if (first_bit == -1)
+ return 1;
+ /* The real exponent of the bottom part is -first_bit. */
+ if (-first_bit < top_exp - 53)
+ return 1;
+ if (-first_bit > top_exp - 53)
+ return 0;
+ /* The bottom part is at least 0.5ulp of the top part. For this
+ to be OK, the bottom part must be exactly 0.5ulp (i.e. no
+ more bits set) and the top part must have last bit 0. */
+ if (second_bit != -1)
+ return 0;
+ return !get_field (ufrom, hfmt->byteorder, hfmt->totalsize,
+ hfmt->man_start + hfmt->man_len - 1, 1);
+ }
+ else
+ {
+ /* The bottom part is at least 0.5ulp of the top part. For this
+ to be OK, it must be exactly 0.5ulp (i.e. no explicit bits
+ set) and the top part must have last bit 0. */
+ if (get_field (ufrom, hfmt->byteorder, hfmt->totalsize,
+ hfmt->man_start + hfmt->man_len - 1, 1))
+ return 0;
+ return !mant_bits_set (hfmt, ufrom + 8);
+ }
+}
+
+const struct floatformat floatformat_ibm_long_double =
+{
+ floatformat_big, 128, 0, 1, 11, 1023, 2047, 12, 52,
+ floatformat_intbit_no,
+ "floatformat_ibm_long_double",
+ floatformat_ibm_long_double_is_valid,
+ &floatformat_ieee_double_big
};
\f
-static unsigned long get_field PARAMS ((unsigned char *,
- enum floatformat_byteorders,
- unsigned int,
- unsigned int,
- unsigned int));
-/* Extract a field which starts at START and is LEN bytes long. DATA and
+#ifndef min
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+/* Return 1 if any bits are explicitly set in the mantissa of UFROM,
+ format FMT, 0 otherwise. */
+static int
+mant_bits_set (const struct floatformat *fmt, const unsigned char *ufrom)
+{
+ unsigned int mant_bits, mant_off;
+ int mant_bits_left;
+
+ mant_off = fmt->man_start;
+ mant_bits_left = fmt->man_len;
+ while (mant_bits_left > 0)
+ {
+ mant_bits = min (mant_bits_left, 32);
+
+ if (get_field (ufrom, fmt->byteorder, fmt->totalsize,
+ mant_off, mant_bits) != 0)
+ return 1;
+
+ mant_off += mant_bits;
+ mant_bits_left -= mant_bits;
+ }
+ return 0;
+}
+
+/* Extract a field which starts at START and is LEN bits long. DATA and
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
static unsigned long
-get_field (data, order, total_len, start, len)
- unsigned char *data;
- enum floatformat_byteorders order;
- unsigned int total_len;
- unsigned int start;
- unsigned int len;
+get_field (const unsigned char *data, enum floatformat_byteorders order,
+ unsigned int total_len, unsigned int start, unsigned int len)
{
- unsigned long result;
+ unsigned long result = 0;
unsigned int cur_byte;
- int cur_bitshift;
+ int lo_bit, hi_bit, cur_bitshift = 0;
+ int nextbyte = (order == floatformat_little) ? 1 : -1;
+
+ /* Start is in big-endian bit order! Fix that first. */
+ start = total_len - (start + len);
/* Start at the least significant part of the field. */
- cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT;
if (order == floatformat_little)
- cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1;
- cur_bitshift =
- ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT;
- result = *(data + cur_byte) >> (-cur_bitshift);
- cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little)
- ++cur_byte;
+ cur_byte = start / FLOATFORMAT_CHAR_BIT;
else
- --cur_byte;
+ cur_byte = (total_len - start - 1) / FLOATFORMAT_CHAR_BIT;
- /* Move towards the most significant part of the field. */
- while ((unsigned int) cur_bitshift < len)
+ lo_bit = start % FLOATFORMAT_CHAR_BIT;
+ hi_bit = min (lo_bit + len, FLOATFORMAT_CHAR_BIT);
+
+ do
{
- if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT)
- /* This is the last byte; zero out the bits which are not part of
- this field. */
- result |=
- (*(data + cur_byte) & ((1 << (len - cur_bitshift)) - 1))
- << cur_bitshift;
- else
- result |= *(data + cur_byte) << cur_bitshift;
- cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little)
- ++cur_byte;
- else
- --cur_byte;
+ unsigned int shifted = *(data + cur_byte) >> lo_bit;
+ unsigned int bits = hi_bit - lo_bit;
+ unsigned int mask = (1 << bits) - 1;
+ result |= (shifted & mask) << cur_bitshift;
+ len -= bits;
+ cur_bitshift += bits;
+ cur_byte += nextbyte;
+ lo_bit = 0;
+ hi_bit = min (len, FLOATFORMAT_CHAR_BIT);
}
+ while (len != 0);
+
return result;
}
-#ifndef min
-#define min(a, b) ((a) < (b) ? (a) : (b))
-#endif
-
/* Convert from FMT to a double.
FROM is the address of the extended float.
Store the double in *TO. */
void
-floatformat_to_double (fmt, from, to)
- const struct floatformat *fmt;
- char *from;
- double *to;
+floatformat_to_double (const struct floatformat *fmt,
+ const void *from, double *to)
{
- unsigned char *ufrom = (unsigned char *)from;
+ const unsigned char *ufrom = (const unsigned char *) from;
double dto;
long exponent;
unsigned long mant;
int mant_bits_left;
int special_exponent; /* It's a NaN, denorm or zero */
+ /* Split values are not handled specially, since the top half has
+ the correctly rounded double value (in the only supported case of
+ split values). */
+
exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
fmt->exp_start, fmt->exp_len);
- /* Note that if exponent indicates a NaN, we can't really do anything useful
- (not knowing if the host has NaN's, or how to build one). So it will
- end up as an infinity or something close; that is OK. */
+
+ /* If the exponent indicates a NaN, we don't have information to
+ decide what to do. So we handle it like IEEE, except that we
+ don't try to preserve the type of NaN. FIXME. */
+ if ((unsigned long) exponent == fmt->exp_nan)
+ {
+ int nan = mant_bits_set (fmt, ufrom);
+
+ /* On certain systems (such as GNU/Linux), the use of the
+ INFINITY macro below may generate a warning that can not be
+ silenced due to a bug in GCC (PR preprocessor/11931). The
+ preprocessor fails to recognise the __extension__ keyword in
+ conjunction with the GNU/C99 extension for hexadecimal
+ floating point constants and will issue a warning when
+ compiling with -pedantic. */
+ if (nan)
+ dto = NAN;
+ else
+ dto = INFINITY;
+
+ if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
+ dto = -dto;
+
+ *to = dto;
+
+ return;
+ }
mant_bits_left = fmt->man_len;
mant_off = fmt->man_start;
mant = get_field (ufrom, fmt->byteorder, fmt->totalsize,
mant_off, mant_bits);
- dto += ldexp ((double)mant, exponent - mant_bits);
- exponent -= mant_bits;
+ /* Handle denormalized numbers. FIXME: What should we do for
+ non-IEEE formats? */
+ if (special_exponent && exponent == 0 && mant != 0)
+ dto += ldexp ((double)mant,
+ (- fmt->exp_bias
+ - mant_bits
+ - (mant_off - fmt->man_start)
+ + 1));
+ else
+ dto += ldexp ((double)mant, exponent - mant_bits);
+ if (exponent != 0)
+ exponent -= mant_bits;
mant_off += mant_bits;
mant_bits_left -= mant_bits;
}
*to = dto;
}
\f
-static void put_field PARAMS ((unsigned char *, enum floatformat_byteorders,
- unsigned int,
- unsigned int,
- unsigned int,
- unsigned long));
+static void put_field (unsigned char *, enum floatformat_byteorders,
+ unsigned int,
+ unsigned int,
+ unsigned int,
+ unsigned long);
-/* Set a field which starts at START and is LEN bytes long. DATA and
+/* Set a field which starts at START and is LEN bits long. DATA and
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
static void
-put_field (data, order, total_len, start, len, stuff_to_put)
- unsigned char *data;
- enum floatformat_byteorders order;
- unsigned int total_len;
- unsigned int start;
- unsigned int len;
- unsigned long stuff_to_put;
+put_field (unsigned char *data, enum floatformat_byteorders order,
+ unsigned int total_len, unsigned int start, unsigned int len,
+ unsigned long stuff_to_put)
{
unsigned int cur_byte;
- int cur_bitshift;
+ int lo_bit, hi_bit;
+ int nextbyte = (order == floatformat_little) ? 1 : -1;
+
+ /* Start is in big-endian bit order! Fix that first. */
+ start = total_len - (start + len);
/* Start at the least significant part of the field. */
- cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT;
if (order == floatformat_little)
- cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1;
- cur_bitshift =
- ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT;
- *(data + cur_byte) &=
- ~(((1 << ((start + len) % FLOATFORMAT_CHAR_BIT)) - 1) << (-cur_bitshift));
- *(data + cur_byte) |=
- (stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift);
- cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little)
- ++cur_byte;
+ cur_byte = start / FLOATFORMAT_CHAR_BIT;
else
- --cur_byte;
+ cur_byte = (total_len - start - 1) / FLOATFORMAT_CHAR_BIT;
- /* Move towards the most significant part of the field. */
- while ((unsigned int) cur_bitshift < len)
+ lo_bit = start % FLOATFORMAT_CHAR_BIT;
+ hi_bit = min (lo_bit + len, FLOATFORMAT_CHAR_BIT);
+
+ do
{
- if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT)
- {
- /* This is the last byte. */
- *(data + cur_byte) &=
- ~((1 << (len - cur_bitshift)) - 1);
- *(data + cur_byte) |= (stuff_to_put >> cur_bitshift);
- }
- else
- *(data + cur_byte) = ((stuff_to_put >> cur_bitshift)
- & ((1 << FLOATFORMAT_CHAR_BIT) - 1));
- cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little)
- ++cur_byte;
- else
- --cur_byte;
+ unsigned char *byte_ptr = data + cur_byte;
+ unsigned int bits = hi_bit - lo_bit;
+ unsigned int mask = ((1 << bits) - 1) << lo_bit;
+ *byte_ptr = (*byte_ptr & ~mask) | ((stuff_to_put << lo_bit) & mask);
+ stuff_to_put >>= bits;
+ len -= bits;
+ cur_byte += nextbyte;
+ lo_bit = 0;
+ hi_bit = min (len, FLOATFORMAT_CHAR_BIT);
}
+ while (len != 0);
}
/* The converse: convert the double *FROM to an extended float
restrictions. */
void
-floatformat_from_double (fmt, from, to)
- const struct floatformat *fmt;
- double *from;
- char *to;
+floatformat_from_double (const struct floatformat *fmt,
+ const double *from, void *to)
{
double dfrom;
int exponent;
double mant;
unsigned int mant_bits, mant_off;
int mant_bits_left;
- unsigned char *uto = (unsigned char *)to;
+ unsigned char *uto = (unsigned char *) to;
- memcpy (&dfrom, from, sizeof (dfrom));
+ dfrom = *from;
memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT);
+
+ /* Split values are not handled specially, since a bottom half of
+ zero is correct for any value representable as double (in the
+ only supported case of split values). */
+
+ /* If negative, set the sign bit. */
+ if (dfrom < 0)
+ {
+ put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1);
+ dfrom = -dfrom;
+ }
+
if (dfrom == 0)
- return; /* Result is zero */
+ {
+ /* 0.0. */
+ return;
+ }
+
if (dfrom != dfrom)
{
- /* From is NaN */
+ /* NaN. */
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
fmt->exp_len, fmt->exp_nan);
- /* Be sure it's not infinity, but NaN value is irrel */
+ /* Be sure it's not infinity, but NaN value is irrelevant. */
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start,
32, 1);
return;
}
- /* If negative, set the sign bit. */
- if (dfrom < 0)
+ if (dfrom + dfrom == dfrom)
{
- put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1);
- dfrom = -dfrom;
+ /* This can only happen for an infinite value (or zero, which we
+ already handled above). */
+ put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, fmt->exp_nan);
+ return;
}
- /* How to tell an infinity from an ordinary number? FIXME-someday */
-
mant = frexp (dfrom, &exponent);
- put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, fmt->exp_len,
- exponent + fmt->exp_bias - 1);
+ if (exponent + fmt->exp_bias - 1 > 0)
+ put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, exponent + fmt->exp_bias - 1);
+ else
+ {
+ /* Handle a denormalized number. FIXME: What should we do for
+ non-IEEE formats? */
+ put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, 0);
+ mant = ldexp (mant, exponent + fmt->exp_bias - 1);
+ }
mant_bits_left = fmt->man_len;
mant_off = fmt->man_start;
mant_long = (unsigned long)mant;
mant -= mant_long;
- /* If the integer bit is implicit, then we need to discard it.
- If we are discarding a zero, we should be (but are not) creating
- a denormalized number which means adjusting the exponent
- (I think). */
+ /* If the integer bit is implicit, and we are not creating a
+ denormalized number, then we need to discard it. */
if ((unsigned int) mant_bits_left == fmt->man_len
- && fmt->intbit == floatformat_intbit_no)
+ && fmt->intbit == floatformat_intbit_no
+ && exponent + fmt->exp_bias - 1 > 0)
{
mant_long &= 0x7fffffff;
mant_bits -= 1;
}
}
+/* Return non-zero iff the data at FROM is a valid number in format FMT. */
+
+int
+floatformat_is_valid (const struct floatformat *fmt, const void *from)
+{
+ return fmt->is_valid (fmt, from);
+}
+
#ifdef IEEE_DEBUG
+#include <stdio.h>
+
/* This is to be run on a host which uses IEEE floating point. */
void
-ieee_test (n)
- double n;
+ieee_test (double n)
{
double result;
- char exten[16];
- floatformat_to_double (&floatformat_ieee_double_big, &n, &result);
- if (n != result)
+ floatformat_to_double (&floatformat_ieee_double_little, &n, &result);
+ if ((n != result && (! isnan (n) || ! isnan (result)))
+ || (n < 0 && result >= 0)
+ || (n >= 0 && result < 0))
printf ("Differ(to): %.20g -> %.20g\n", n, result);
- floatformat_from_double (&floatformat_ieee_double_big, &n, &result);
- if (n != result)
+
+ floatformat_from_double (&floatformat_ieee_double_little, &n, &result);
+ if ((n != result && (! isnan (n) || ! isnan (result)))
+ || (n < 0 && result >= 0)
+ || (n >= 0 && result < 0))
printf ("Differ(from): %.20g -> %.20g\n", n, result);
- floatformat_from_double (&floatformat_m68881_ext, &n, exten);
- floatformat_to_double (&floatformat_m68881_ext, exten, &result);
- if (n != result)
- printf ("Differ(to+from): %.20g -> %.20g\n", n, result);
+#if 0
+ {
+ char exten[16];
+
+ floatformat_from_double (&floatformat_m68881_ext, &n, exten);
+ floatformat_to_double (&floatformat_m68881_ext, exten, &result);
+ if (n != result)
+ printf ("Differ(to+from): %.20g -> %.20g\n", n, result);
+ }
+#endif
#if IEEE_DEBUG > 1
/* This is to be run on a host which uses 68881 format. */
}
int
-main ()
+main (void)
{
+ ieee_test (0.0);
ieee_test (0.5);
ieee_test (256.0);
ieee_test (0.12345);
ieee_test (234235.78907234);
ieee_test (-512.0);
ieee_test (-0.004321);
+ ieee_test (1.2E-70);
+ ieee_test (1.2E-316);
+ ieee_test (4.9406564584124654E-324);
+ ieee_test (- 4.9406564584124654E-324);
+ ieee_test (- 0.0);
+ ieee_test (- INFINITY);
+ ieee_test (- NAN);
+ ieee_test (INFINITY);
+ ieee_test (NAN);
return 0;
}
#endif
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