/* Floating point routines for GDB, the GNU debugger.
- Copyright (C) 1986-2013 Free Software Foundation, Inc.
+ Copyright (C) 1986-2017 Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "doublest.h"
#include "floatformat.h"
-#include "gdb_assert.h"
-#include "gdb_string.h"
#include "gdbtypes.h"
#include <math.h> /* ldexp */
+#include <algorithm>
/* 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
/* For non-numbers, reuse libiberty's logic to find the correct
format. We do not lose any precision in this case by passing
through a double. */
- kind = floatformat_classify (fmt, from);
+ kind = floatformat_classify (fmt, (const bfd_byte *) from);
if (kind == float_infinite || kind == float_nan)
{
double dto;
- floatformat_to_double (fmt, from, &dto);
+ floatformat_to_double (fmt->split_half ? fmt->split_half : fmt,
+ from, &dto);
*to = (DOUBLEST) dto;
return;
}
while (mant_bits_left > 0)
{
- mant_bits = min (mant_bits_left, 32);
+ mant_bits = std::min (mant_bits_left, 32);
mant = get_field (ufrom, order, fmt->totalsize, mant_off, mant_bits);
}
}
-#ifdef HAVE_LONG_DOUBLE
-/* Return the fractional part of VALUE, and put the exponent of VALUE in *EPTR.
- The range of the returned value is >= 0.5 and < 1.0. This is equivalent to
- frexp, but operates on the long double data type. */
-
-static long double ldfrexp (long double value, int *eptr);
-
-static long double
-ldfrexp (long double value, int *eptr)
-{
- long double tmp;
- int exp;
-
- /* Unfortunately, there are no portable functions for extracting the
- exponent of a long double, so we have to do it iteratively by
- multiplying or dividing by two until the fraction is between 0.5
- and 1.0. */
-
- if (value < 0.0l)
- value = -value;
-
- tmp = 1.0l;
- exp = 0;
-
- if (value >= tmp) /* Value >= 1.0 */
- while (value >= tmp)
- {
- tmp *= 2.0l;
- exp++;
- }
- else if (value != 0.0l) /* Value < 1.0 and > 0.0 */
- {
- while (value < tmp)
- {
- tmp /= 2.0l;
- exp--;
- }
- tmp *= 2.0l;
- exp++;
- }
-
- *eptr = exp;
- return value / tmp;
-}
-#endif /* HAVE_LONG_DOUBLE */
-
-
/* The converse: convert the DOUBLEST *FROM to an extended float and
store where TO points. Neither FROM nor TO have any alignment
restrictions. */
static void
-convert_doublest_to_floatformat (CONST struct floatformat *fmt,
+convert_doublest_to_floatformat (const struct floatformat *fmt,
const DOUBLEST *from, void *to)
{
DOUBLEST dfrom;
uto = newto;
memcpy (&dfrom, from, sizeof (dfrom));
- memset (uto, 0, (fmt->totalsize + FLOATFORMAT_CHAR_BIT - 1)
- / FLOATFORMAT_CHAR_BIT);
+ memset (uto, 0, floatformat_totalsize_bytes (fmt));
if (fmt->split_half)
{
}
#ifdef HAVE_LONG_DOUBLE
- mant = ldfrexp (dfrom, &exponent);
+ mant = frexpl (dfrom, &exponent);
#else
mant = frexp (dfrom, &exponent);
#endif
gdb_assert (fmt->totalsize
<= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
+ /* An IBM long double (a two element array of double) always takes the
+ sign of the first double. */
+ if (fmt->split_half)
+ fmt = fmt->split_half;
+
order = floatformat_normalize_byteorder (fmt, uval, newfrom);
if (order != fmt->byteorder)
gdb_assert (fmt->totalsize
<= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
+ /* An IBM long double (a two element array of double) can be classified
+ by looking at the first double. inf and nan are specified as
+ ignoring the second double. zero and subnormal will always have
+ the second double 0.0 if the long double is correctly rounded. */
+ if (fmt->split_half)
+ fmt = fmt->split_half;
+
order = floatformat_normalize_byteorder (fmt, uval, newfrom);
if (order != fmt->byteorder)
mant_zero = 1;
while (mant_bits_left > 0)
{
- mant_bits = min (mant_bits_left, 32);
+ mant_bits = std::min (mant_bits_left, 32);
mant = get_field (uval, order, fmt->totalsize, mant_off, mant_bits);
gdb_assert (fmt->totalsize
<= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
+ /* For IBM long double (a two element array of double), return the
+ mantissa of the first double. The problem with returning the
+ actual mantissa from both doubles is that there can be an
+ arbitrary number of implied 0's or 1's between the mantissas
+ of the first and second double. In any case, this function
+ is only used for dumping out nans, and a nan is specified to
+ ignore the value in the second double. */
+ if (fmt->split_half)
+ fmt = fmt->split_half;
+
order = floatformat_normalize_byteorder (fmt, uval, newfrom);
if (order != fmt->byteorder)
If the host and target formats agree, we just copy the raw data
into the appropriate type of variable and return, letting the host
increase precision as necessary. Otherwise, we call the conversion
- routine and let it do the dirty work. */
+ routine and let it do the dirty work. Note that even if the target
+ and host floating-point formats match, the length of the types
+ might still be different, so the conversion routines must make sure
+ to not overrun any buffers. For example, on x86, long double is
+ the 80-bit extended precision type on both 32-bit and 64-bit ABIs,
+ but by default it is stored as 12 bytes on 32-bit, and 16 bytes on
+ 64-bit, for alignment reasons. See comment in store_typed_floating
+ for a discussion about zeroing out remaining bytes in the target
+ buffer. */
static const struct floatformat *host_float_format = GDB_HOST_FLOAT_FORMAT;
static const struct floatformat *host_double_format = GDB_HOST_DOUBLE_FORMAT;
static const struct floatformat *host_long_double_format
= GDB_HOST_LONG_DOUBLE_FORMAT;
+/* See doublest.h. */
+
+size_t
+floatformat_totalsize_bytes (const struct floatformat *fmt)
+{
+ return ((fmt->totalsize + FLOATFORMAT_CHAR_BIT - 1)
+ / FLOATFORMAT_CHAR_BIT);
+}
+
void
floatformat_to_doublest (const struct floatformat *fmt,
const void *in, DOUBLEST *out)
{
gdb_assert (fmt != NULL);
+
if (fmt == host_float_format)
{
- float val;
+ float val = 0;
- memcpy (&val, in, sizeof (val));
+ memcpy (&val, in, floatformat_totalsize_bytes (fmt));
*out = val;
}
else if (fmt == host_double_format)
{
- double val;
+ double val = 0;
- memcpy (&val, in, sizeof (val));
+ memcpy (&val, in, floatformat_totalsize_bytes (fmt));
*out = val;
}
else if (fmt == host_long_double_format)
{
- long double val;
+ long double val = 0;
- memcpy (&val, in, sizeof (val));
+ memcpy (&val, in, floatformat_totalsize_bytes (fmt));
*out = val;
}
else
const DOUBLEST *in, void *out)
{
gdb_assert (fmt != NULL);
+
if (fmt == host_float_format)
{
float val = *in;
- memcpy (out, &val, sizeof (val));
+ memcpy (out, &val, floatformat_totalsize_bytes (fmt));
}
else if (fmt == host_double_format)
{
double val = *in;
- memcpy (out, &val, sizeof (val));
+ memcpy (out, &val, floatformat_totalsize_bytes (fmt));
}
else if (fmt == host_long_double_format)
{
long double val = *in;
- memcpy (out, &val, sizeof (val));
+ memcpy (out, &val, floatformat_totalsize_bytes (fmt));
}
else
convert_doublest_to_floatformat (fmt, in, out);
}
\f
-/* Return a floating-point format for a floating-point variable of
- length LEN. If no suitable floating-point format is found, an
- error is thrown.
-
- We need this functionality since information about the
- floating-point format of a type is not always available to GDB; the
- debug information typically only tells us the size of a
- floating-point type.
-
- FIXME: kettenis/2001-10-28: In many places, particularly in
- target-dependent code, the format of floating-point types is known,
- but not passed on by GDB. This should be fixed. */
-
-static const struct floatformat *
-floatformat_from_length (struct gdbarch *gdbarch, int len)
-{
- const struct floatformat *format;
-
- if (len * TARGET_CHAR_BIT == gdbarch_half_bit (gdbarch))
- format = gdbarch_half_format (gdbarch)
- [gdbarch_byte_order (gdbarch)];
- else if (len * TARGET_CHAR_BIT == gdbarch_float_bit (gdbarch))
- format = gdbarch_float_format (gdbarch)
- [gdbarch_byte_order (gdbarch)];
- else if (len * TARGET_CHAR_BIT == gdbarch_double_bit (gdbarch))
- format = gdbarch_double_format (gdbarch)
- [gdbarch_byte_order (gdbarch)];
- else if (len * TARGET_CHAR_BIT == gdbarch_long_double_bit (gdbarch))
- format = gdbarch_long_double_format (gdbarch)
- [gdbarch_byte_order (gdbarch)];
- /* On i386 the 'long double' type takes 96 bits,
- while the real number of used bits is only 80,
- both in processor and in memory.
- The code below accepts the real bit size. */
- else if ((gdbarch_long_double_format (gdbarch) != NULL)
- && (len * TARGET_CHAR_BIT
- == gdbarch_long_double_format (gdbarch)[0]->totalsize))
- format = gdbarch_long_double_format (gdbarch)
- [gdbarch_byte_order (gdbarch)];
- else
- format = NULL;
- if (format == NULL)
- error (_("Unrecognized %d-bit floating-point type."),
- len * TARGET_CHAR_BIT);
- return format;
-}
+/* Return the floating-point format for a floating-point variable of
+ type TYPE. */
const struct floatformat *
floatformat_from_type (const struct type *type)
{
struct gdbarch *gdbarch = get_type_arch (type);
+ const struct floatformat *fmt;
gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
- if (TYPE_FLOATFORMAT (type) != NULL)
- return TYPE_FLOATFORMAT (type)[gdbarch_byte_order (gdbarch)];
- else
- return floatformat_from_length (gdbarch, TYPE_LENGTH (type));
+ gdb_assert (TYPE_FLOATFORMAT (type));
+ fmt = TYPE_FLOATFORMAT (type)[gdbarch_byte_order (gdbarch)];
+ gdb_assert (TYPE_LENGTH (type) >= floatformat_totalsize_bytes (fmt));
+ return fmt;
}
/* Extract a floating-point number of type TYPE from a target-order
comment in store_typed_floating for a discussion about
zeroing out remaining bytes in the target buffer. */
memset (to, 0, TYPE_LENGTH (to_type));
- memcpy (to, from, min (TYPE_LENGTH (from_type), TYPE_LENGTH (to_type)));
+ memcpy (to, from, std::min (TYPE_LENGTH (from_type),
+ TYPE_LENGTH (to_type)));
}
else
{
floatformat_from_doublest (to_fmt, &d, to);
}
}
-
-const struct floatformat *floatformat_ieee_single[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_ieee_double[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_ieee_quad[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_arm_ext[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_ia64_spill[BFD_ENDIAN_UNKNOWN];
-
-extern void _initialize_doublest (void);
-
-extern void
-_initialize_doublest (void)
-{
- floatformat_ieee_single[BFD_ENDIAN_LITTLE] = &floatformat_ieee_single_little;
- floatformat_ieee_single[BFD_ENDIAN_BIG] = &floatformat_ieee_single_big;
- floatformat_ieee_double[BFD_ENDIAN_LITTLE] = &floatformat_ieee_double_little;
- floatformat_ieee_double[BFD_ENDIAN_BIG] = &floatformat_ieee_double_big;
- floatformat_arm_ext[BFD_ENDIAN_LITTLE]
- = &floatformat_arm_ext_littlebyte_bigword;
- floatformat_arm_ext[BFD_ENDIAN_BIG] = &floatformat_arm_ext_big;
- floatformat_ia64_spill[BFD_ENDIAN_LITTLE] = &floatformat_ia64_spill_little;
- floatformat_ia64_spill[BFD_ENDIAN_BIG] = &floatformat_ia64_spill_big;
- floatformat_ieee_quad[BFD_ENDIAN_LITTLE] = &floatformat_ia64_quad_little;
- floatformat_ieee_quad[BFD_ENDIAN_BIG] = &floatformat_ia64_quad_big;
-}
projects / deliverable / binutils-gdb.git / blobdiff