/* Floating point routines for GDB, the GNU debugger.
- Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
- 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2007
- Free Software Foundation, Inc.
+ Copyright (C) 1986-2013 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
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., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Support for converting target fp numbers into host DOUBLEST format. */
{
/* We start counting from the other end (i.e, from the high bytes
rather than the low bytes). As such, we need to be concerned
- with what happens if bit 0 doesn't start on a byte boundary.
+ with what happens if bit 0 doesn't start on a byte boundary.
I.e, we need to properly handle the case where total_len is
not evenly divisible by 8. So we compute ``excess'' which
represents the number of bits from the end of our starting
- byte needed to get to bit 0. */
+ byte needed to get to bit 0. */
int excess = FLOATFORMAT_CHAR_BIT - (total_len % FLOATFORMAT_CHAR_BIT);
+
cur_byte = (total_len / FLOATFORMAT_CHAR_BIT)
- ((start + len + excess) / FLOATFORMAT_CHAR_BIT);
cur_bitshift = ((start + len + excess) % FLOATFORMAT_CHAR_BIT)
}
}
if (len < sizeof(result) * FLOATFORMAT_CHAR_BIT)
- /* Mask out bits which are not part of the field */
+ /* Mask out bits which are not part of the field. */
result &= ((1UL << len) - 1);
return result;
}
unsigned long mant;
unsigned int mant_bits, mant_off;
int mant_bits_left;
- int special_exponent; /* It's a NaN, denorm or zero */
+ int special_exponent; /* It's a NaN, denorm or zero. */
enum floatformat_byteorders order;
unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES];
enum float_kind kind;
if (kind == float_infinite || kind == float_nan)
{
double dto;
+
floatformat_to_double (fmt, from, &dto);
*to = (DOUBLEST) dto;
return;
if (order != fmt->byteorder)
ufrom = newfrom;
+ if (fmt->split_half)
+ {
+ DOUBLEST dtop, dbot;
+
+ floatformat_to_doublest (fmt->split_half, ufrom, &dtop);
+ /* Preserve the sign of 0, which is the sign of the top
+ half. */
+ if (dtop == 0.0)
+ {
+ *to = dtop;
+ return;
+ }
+ floatformat_to_doublest (fmt->split_half,
+ ufrom + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2,
+ &dbot);
+ *to = dtop + dbot;
+ return;
+ }
+
exponent = get_field (ufrom, order, fmt->totalsize, fmt->exp_start,
fmt->exp_len);
/* Note that if exponent indicates a NaN, we can't really do anything useful
special_exponent = exponent == 0 || exponent == fmt->exp_nan;
- /* Don't bias NaNs. Use minimum exponent for denorms. For simplicity,
- we don't check for zero as the exponent doesn't matter. Note the cast
- to int; exp_bias is unsigned, so it's important to make sure the
- operation is done in signed arithmetic. */
+ /* Don't bias NaNs. Use minimum exponent for denorms. For
+ simplicity, we don't check for zero as the exponent doesn't matter.
+ Note the cast to int; exp_bias is unsigned, so it's important to
+ make sure the operation is done in signed arithmetic. */
if (!special_exponent)
exponent -= fmt->exp_bias;
else if (exponent == 0)
exponent = 1 - fmt->exp_bias;
/* Build the result algebraically. Might go infinite, underflow, etc;
- who cares. */
+ who cares. */
/* If this format uses a hidden bit, explicitly add it in now. Otherwise,
increment the exponent by one to account for the integer bit. */
*to = dto;
}
\f
-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
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
static void
if (order == floatformat_little)
{
int excess = FLOATFORMAT_CHAR_BIT - (total_len % FLOATFORMAT_CHAR_BIT);
+
cur_byte = (total_len / FLOATFORMAT_CHAR_BIT)
- ((start + len + excess) / FLOATFORMAT_CHAR_BIT);
cur_bitshift = ((start + len + excess) % FLOATFORMAT_CHAR_BIT)
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. */
+ /* 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;
memcpy (&dfrom, from, sizeof (dfrom));
memset (uto, 0, (fmt->totalsize + FLOATFORMAT_CHAR_BIT - 1)
/ FLOATFORMAT_CHAR_BIT);
+
+ if (fmt->split_half)
+ {
+ /* Use static volatile to ensure that any excess precision is
+ removed via storing in memory, and so the top half really is
+ the result of converting to double. */
+ static volatile double dtop, dbot;
+ DOUBLEST dtopnv, dbotnv;
+
+ dtop = (double) dfrom;
+ /* If the rounded top half is Inf, the bottom must be 0 not NaN
+ or Inf. */
+ if (dtop + dtop == dtop && dtop != 0.0)
+ dbot = 0.0;
+ else
+ dbot = (double) (dfrom - (DOUBLEST) dtop);
+ dtopnv = dtop;
+ dbotnv = dbot;
+ floatformat_from_doublest (fmt->split_half, &dtopnv, uto);
+ floatformat_from_doublest (fmt->split_half, &dbotnv,
+ (uto
+ + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2));
+ return;
+ }
+
if (dfrom == 0)
return; /* Result is zero */
if (dfrom != dfrom) /* Result is NaN */
/* From is NaN */
put_field (uto, order, 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 irrel. */
put_field (uto, order, fmt->totalsize, fmt->man_start,
- 32, 1);
+ fmt->man_len, 1);
goto finalize_byteorder;
}
dfrom = -dfrom;
}
- if (dfrom + dfrom == dfrom && dfrom != 0.0) /* Result is Infinity */
+ if (dfrom + dfrom == dfrom && dfrom != 0.0) /* Result is Infinity. */
{
/* Infinity exponent is same as NaN's. */
put_field (uto, order, fmt->totalsize, fmt->exp_start,
mant = frexp (dfrom, &exponent);
#endif
+ if (exponent + fmt->exp_bias <= 0)
+ {
+ /* The value is too small to be expressed in the destination
+ type (not enough bits in the exponent. Treat as 0. */
+ put_field (uto, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, 0);
+ put_field (uto, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 0);
+ goto finalize_byteorder;
+ }
+
+ if (exponent + fmt->exp_bias >= (1 << fmt->exp_len))
+ {
+ /* The value is too large to fit into the destination.
+ Treat as infinity. */
+ put_field (uto, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, fmt->exp_nan);
+ put_field (uto, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 0);
+ goto finalize_byteorder;
+ }
+
put_field (uto, order, fmt->totalsize, fmt->exp_start, fmt->exp_len,
exponent + fmt->exp_bias - 1);
while (mant_bits_left > 0)
{
unsigned long mant_long;
+
mant_bits = mant_bits_left < 32 ? mant_bits_left : 32;
mant *= 4294967296.0;
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;
+static const struct floatformat *host_long_double_format
+ = GDB_HOST_LONG_DOUBLE_FORMAT;
void
floatformat_to_doublest (const struct floatformat *fmt,
if (fmt == host_float_format)
{
float val;
+
memcpy (&val, in, sizeof (val));
*out = val;
}
else if (fmt == host_double_format)
{
double val;
+
memcpy (&val, in, sizeof (val));
*out = val;
}
else if (fmt == host_long_double_format)
{
long double val;
+
memcpy (&val, in, sizeof (val));
*out = val;
}
if (fmt == host_float_format)
{
float val = *in;
+
memcpy (out, &val, sizeof (val));
}
else if (fmt == host_double_format)
{
double val = *in;
+
memcpy (out, &val, sizeof (val));
}
else if (fmt == host_long_double_format)
{
long double val = *in;
+
memcpy (out, &val, sizeof (val));
}
else
but not passed on by GDB. This should be fixed. */
static const struct floatformat *
-floatformat_from_length (int len)
+floatformat_from_length (struct gdbarch *gdbarch, int len)
{
const struct floatformat *format;
- if (len * TARGET_CHAR_BIT == TARGET_FLOAT_BIT)
- format = TARGET_FLOAT_FORMAT[TARGET_BYTE_ORDER];
- else if (len * TARGET_CHAR_BIT == TARGET_DOUBLE_BIT)
- format = TARGET_DOUBLE_FORMAT[TARGET_BYTE_ORDER];
- else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
- format = TARGET_LONG_DOUBLE_FORMAT[TARGET_BYTE_ORDER];
+
+ 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.
+ both in processor and in memory.
The code below accepts the real bit size. */
- else if ((TARGET_LONG_DOUBLE_FORMAT != NULL)
- && (len * TARGET_CHAR_BIT ==
- TARGET_LONG_DOUBLE_FORMAT[0]->totalsize))
- format = TARGET_LONG_DOUBLE_FORMAT[TARGET_BYTE_ORDER];
+ 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)
const struct floatformat *
floatformat_from_type (const struct type *type)
{
+ struct gdbarch *gdbarch = get_type_arch (type);
+
gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
if (TYPE_FLOATFORMAT (type) != NULL)
- return TYPE_FLOATFORMAT (type)[TARGET_BYTE_ORDER];
+ return TYPE_FLOATFORMAT (type)[gdbarch_byte_order (gdbarch)];
else
- return floatformat_from_length (TYPE_LENGTH (type));
-}
-
-/* If the host doesn't define NAN, use zero instead. */
-#ifndef NAN
-#define NAN 0.0
-#endif
-
-/* Extract a floating-point number of length LEN from a target-order
- byte-stream at ADDR. Returns the value as type DOUBLEST. */
-
-static DOUBLEST
-extract_floating_by_length (const void *addr, int len)
-{
- const struct floatformat *fmt = floatformat_from_length (len);
- DOUBLEST val;
-
- floatformat_to_doublest (fmt, addr, &val);
- return val;
-}
-
-DOUBLEST
-deprecated_extract_floating (const void *addr, int len)
-{
- return extract_floating_by_length (addr, len);
-}
-
-/* Store VAL as a floating-point number of length LEN to a
- target-order byte-stream at ADDR. */
-
-static void
-store_floating_by_length (void *addr, int len, DOUBLEST val)
-{
- const struct floatformat *fmt = floatformat_from_length (len);
-
- floatformat_from_doublest (fmt, &val, addr);
-}
-
-void
-deprecated_store_floating (void *addr, int len, DOUBLEST val)
-{
- store_floating_by_length (addr, len, val);
+ return floatformat_from_length (gdbarch, TYPE_LENGTH (type));
}
/* Extract a floating-point number of type TYPE from a target-order
DOUBLEST
extract_typed_floating (const void *addr, const struct type *type)
{
+ const struct floatformat *fmt = floatformat_from_type (type);
DOUBLEST retval;
- gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
-
- if (TYPE_FLOATFORMAT (type) == NULL)
- /* Not all code remembers to set the FLOATFORMAT (language
- specific code? stabs?) so handle that here as a special case. */
- return extract_floating_by_length (addr, TYPE_LENGTH (type));
-
- floatformat_to_doublest (TYPE_FLOATFORMAT (type)[TARGET_BYTE_ORDER],
- addr, &retval);
+ floatformat_to_doublest (fmt, addr, &retval);
return retval;
}
void
store_typed_floating (void *addr, const struct type *type, DOUBLEST val)
{
- gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+ const struct floatformat *fmt = floatformat_from_type (type);
/* FIXME: kettenis/2001-10-28: It is debatable whether we should
zero out any remaining bytes in the target buffer when TYPE is
See also the function convert_typed_floating below. */
memset (addr, 0, TYPE_LENGTH (type));
- if (TYPE_FLOATFORMAT (type) == NULL)
- /* Not all code remembers to set the FLOATFORMAT (language
- specific code? stabs?) so handle that here as a special case. */
- store_floating_by_length (addr, TYPE_LENGTH (type), val);
- else
- floatformat_from_doublest (TYPE_FLOATFORMAT (type)[TARGET_BYTE_ORDER],
- &val, addr);
+ floatformat_from_doublest (fmt, &val, addr);
}
/* Convert a floating-point number of type FROM_TYPE from a
const struct floatformat *from_fmt = floatformat_from_type (from_type);
const struct floatformat *to_fmt = floatformat_from_type (to_type);
- gdb_assert (TYPE_CODE (from_type) == TYPE_CODE_FLT);
- gdb_assert (TYPE_CODE (to_type) == TYPE_CODE_FLT);
-
if (from_fmt == NULL || to_fmt == NULL)
{
/* If we don't know the floating-point format of FROM_TYPE or
else
{
/* The floating-point types don't match. The best we can do
- (aport from simulating the target FPU) is converting to the
+ (apart from simulating the target FPU) is converting to the
widest floating-point type supported by the host, and then
again to the desired type. */
DOUBLEST d;
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_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;
projects / binutils.git / blobdiff