/* IEEE floating point support routines, for GDB, the GNU Debugger.
- Copyright (C) 1991, 1994, 1999, 2000, 2003 Free Software Foundation, Inc.
+ Copyright 1991, 1994, 1999, 2000, 2003, 2005, 2006
+ Free Software Foundation, Inc.
This file is part of GDB.
#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"
#endif
#ifndef NAN
+#ifdef DBL_QNAN
+#define NAN DBL_QNAN
+#else
#define NAN (0.0 / 0.0)
#endif
+#endif
static unsigned long get_field (const unsigned char *,
enum floatformat_byteorders,
unsigned int,
unsigned int);
static int floatformat_always_valid (const struct floatformat *fmt,
- const char *from);
+ const void *from);
static int
floatformat_always_valid (const struct floatformat *fmt ATTRIBUTE_UNUSED,
- const char *from ATTRIBUTE_UNUSED)
+ const void *from ATTRIBUTE_UNUSED)
{
return 1;
}
floatformat_always_valid
};
-static int floatformat_i387_ext_is_valid (const struct floatformat *fmt, const char *from);
+/* 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
+};
+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
+};
+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
+};
+
+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 char *from)
+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
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
floatformat_always_valid
};
\f
+
+#ifndef min
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
/* 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 (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 (const struct floatformat *fmt,
- const char *from, double *to)
+ const void *from, double *to)
{
- const unsigned char *ufrom = (const unsigned char *)from;
+ const unsigned char *ufrom = (const unsigned char *) from;
double dto;
long exponent;
unsigned long mant;
/* Handle denormalized numbers. FIXME: What should we do for
non-IEEE formats? */
- if (exponent == 0 && mant != 0)
+ if (special_exponent && exponent == 0 && mant != 0)
dto += ldexp ((double)mant,
(- fmt->exp_bias
- mant_bits
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
void
floatformat_from_double (const struct floatformat *fmt,
- const double *from, char *to)
+ 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;
dfrom = *from;
memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT);
/* Return non-zero iff the data at FROM is a valid number in format FMT. */
int
-floatformat_is_valid (const struct floatformat *fmt, const char *from)
+floatformat_is_valid (const struct floatformat *fmt, const void *from)
{
return fmt->is_valid (fmt, from);
}
{
double result;
- floatformat_to_double (&floatformat_ieee_double_little, (char *) &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_little, &n,
- (char *) &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))
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