along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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
+
#include "ansidecl.h"
+#include "libiberty.h"
#include "floatformat.h"
-#include <math.h> /* ldexp */
-#ifdef ANSI_PROTOTYPES
-#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
-extern char *memcpy ();
-extern char *memset ();
+#define INFINITY (1.0 / 0.0)
+#endif
+#endif
+
+#ifndef NAN
+#define NAN (0.0 / 0.0)
#endif
static unsigned long get_field PARAMS ((const unsigned char *,
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_off = fmt->man_start;
+ mant_bits_left = fmt->man_len;
+ nan = 0;
+ 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)
+ {
+ /* This is a NaN. */
+ nan = 1;
+ break;
+ }
+
+ mant_off += mant_bits;
+ mant_bits_left -= mant_bits;
+ }
+
+ 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 (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;
}
int mant_bits_left;
unsigned char *uto = (unsigned char *)to;
- memcpy (&dfrom, from, sizeof (dfrom));
+ dfrom = *from;
memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT);
+
+ /* 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;
#ifdef IEEE_DEBUG
+#include <stdio.h>
+
/* This is to be run on a host which uses IEEE floating point. */
void
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, (char *) &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,
+ (char *) &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 ()
{
+ 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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