X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fdoublest.c;h=088037eab7163c29ca24cfd4e787211c88d801a3;hb=f3abeff575541dd80e1facd6d0f920e10f77fede;hp=af635f223cb822cd4781cb2e3919618426c634d0;hpb=64f6fcadfcd33a3ea554ab17015de033061db0f8;p=deliverable%2Fbinutils-gdb.git
diff --git a/gdb/doublest.c b/gdb/doublest.c
index af635f223c..088037eab7 100644
--- a/gdb/doublest.c
+++ b/gdb/doublest.c
@@ -1,13 +1,12 @@
/* Floating point routines for GDB, the GNU debugger.
- Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
- 1997, 1998, 1999, 2000, 2001
- Free Software Foundation, Inc.
+
+ Copyright (C) 1986-2016 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,
@@ -16,9 +15,7 @@
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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see . */
/* Support for converting target fp numbers into host DOUBLEST format. */
@@ -29,8 +26,7 @@
#include "defs.h"
#include "doublest.h"
#include "floatformat.h"
-#include "gdb_assert.h"
-#include "gdb_string.h"
+#include "gdbtypes.h"
#include /* ldexp */
/* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not
@@ -38,31 +34,35 @@
a system header, what we do if not, etc. */
#define FLOATFORMAT_CHAR_BIT 8
-static unsigned long get_field (unsigned char *,
- enum floatformat_byteorders,
- unsigned int, unsigned int, unsigned int);
+/* The number of bytes that the largest floating-point type that we
+ can convert to doublest will need. */
+#define FLOATFORMAT_LARGEST_BYTES 16
/* Extract 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 unsigned long
-get_field (unsigned char *data, enum floatformat_byteorders order,
+get_field (const bfd_byte *data, enum floatformat_byteorders order,
unsigned int total_len, unsigned int start, unsigned int len)
{
unsigned long result;
unsigned int cur_byte;
int cur_bitshift;
+ /* Caller must byte-swap words before calling this routine. */
+ gdb_assert (order == floatformat_little || order == floatformat_big);
+
/* Start at the least significant part of the field. */
- if (order == floatformat_little || order == floatformat_littlebyte_bigword)
+ if (order == floatformat_little)
{
/* 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)
@@ -79,7 +79,7 @@ get_field (unsigned char *data, enum floatformat_byteorders order,
else
result = 0;
cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little || order == floatformat_littlebyte_bigword)
+ if (order == floatformat_little)
++cur_byte;
else
--cur_byte;
@@ -89,25 +89,82 @@ get_field (unsigned char *data, enum floatformat_byteorders order,
{
result |= (unsigned long)*(data + cur_byte) << cur_bitshift;
cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little || order == floatformat_littlebyte_bigword)
- ++cur_byte;
- else
- --cur_byte;
+ switch (order)
+ {
+ case floatformat_little:
+ ++cur_byte;
+ break;
+ case floatformat_big:
+ --cur_byte;
+ break;
+ }
}
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;
}
+/* Normalize the byte order of FROM into TO. If no normalization is
+ needed then FMT->byteorder is returned and TO is not changed;
+ otherwise the format of the normalized form in TO is returned. */
+
+static enum floatformat_byteorders
+floatformat_normalize_byteorder (const struct floatformat *fmt,
+ const void *from, void *to)
+{
+ const unsigned char *swapin;
+ unsigned char *swapout;
+ int words;
+
+ if (fmt->byteorder == floatformat_little
+ || fmt->byteorder == floatformat_big)
+ return fmt->byteorder;
+
+ words = fmt->totalsize / FLOATFORMAT_CHAR_BIT;
+ words >>= 2;
+
+ swapout = (unsigned char *)to;
+ swapin = (const unsigned char *)from;
+
+ if (fmt->byteorder == floatformat_vax)
+ {
+ while (words-- > 0)
+ {
+ *swapout++ = swapin[1];
+ *swapout++ = swapin[0];
+ *swapout++ = swapin[3];
+ *swapout++ = swapin[2];
+ swapin += 4;
+ }
+ /* This may look weird, since VAX is little-endian, but it is
+ easier to translate to big-endian than to little-endian. */
+ return floatformat_big;
+ }
+ else
+ {
+ gdb_assert (fmt->byteorder == floatformat_littlebyte_bigword);
+
+ while (words-- > 0)
+ {
+ *swapout++ = swapin[3];
+ *swapout++ = swapin[2];
+ *swapout++ = swapin[1];
+ *swapout++ = swapin[0];
+ swapin += 4;
+ }
+ return floatformat_big;
+ }
+}
+
/* Convert from FMT to a DOUBLEST.
FROM is the address of the extended float.
Store the DOUBLEST in *TO. */
-void
-floatformat_to_doublest (const struct floatformat *fmt,
- const void *from,
- DOUBLEST *to)
+static void
+convert_floatformat_to_doublest (const struct floatformat *fmt,
+ const void *from,
+ DOUBLEST *to)
{
unsigned char *ufrom = (unsigned char *) from;
DOUBLEST dto;
@@ -115,52 +172,54 @@ floatformat_to_doublest (const struct floatformat *fmt,
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;
+
+ gdb_assert (fmt->totalsize
+ <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
+
+ /* 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, (const bfd_byte *) from);
+ if (kind == float_infinite || kind == float_nan)
+ {
+ double dto;
+
+ floatformat_to_double (fmt->split_half ? fmt->split_half : fmt,
+ from, &dto);
+ *to = (DOUBLEST) dto;
+ return;
+ }
- /* If the mantissa bits are not contiguous from one end of the
- mantissa to the other, we need to make a private copy of the
- source bytes that is in the right order since the unpacking
- algorithm assumes that the bits are contiguous.
+ order = floatformat_normalize_byteorder (fmt, ufrom, newfrom);
- Swap the bytes individually rather than accessing them through
- "long *" since we have no guarantee that they start on a long
- alignment, and also sizeof(long) for the host could be different
- than sizeof(long) for the target. FIXME: Assumes sizeof(long)
- for the target is 4. */
+ if (order != fmt->byteorder)
+ ufrom = newfrom;
- if (fmt->byteorder == floatformat_littlebyte_bigword)
+ if (fmt->split_half)
{
- static unsigned char *newfrom;
- unsigned char *swapin, *swapout;
- int longswaps;
-
- longswaps = fmt->totalsize / FLOATFORMAT_CHAR_BIT;
- longswaps >>= 3;
+ DOUBLEST dtop, dbot;
- if (newfrom == NULL)
+ 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)
{
- newfrom = (unsigned char *) xmalloc (fmt->totalsize);
- }
- swapout = newfrom;
- swapin = ufrom;
- ufrom = newfrom;
- while (longswaps-- > 0)
- {
- /* This is ugly, but efficient */
- *swapout++ = swapin[4];
- *swapout++ = swapin[5];
- *swapout++ = swapin[6];
- *swapout++ = swapin[7];
- *swapout++ = swapin[0];
- *swapout++ = swapin[1];
- *swapout++ = swapin[2];
- *swapout++ = swapin[3];
- swapin += 8;
+ *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, fmt->byteorder, fmt->totalsize,
- fmt->exp_start, fmt->exp_len);
+ 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
(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. */
@@ -171,15 +230,17 @@ floatformat_to_doublest (const struct floatformat *fmt,
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. */
+ /* 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. */
@@ -196,8 +257,7 @@ floatformat_to_doublest (const struct floatformat *fmt,
{
mant_bits = min (mant_bits_left, 32);
- mant = get_field (ufrom, fmt->byteorder, fmt->totalsize,
- mant_off, mant_bits);
+ mant = get_field (ufrom, order, fmt->totalsize, mant_off, mant_bits);
dto += ldexp ((double) mant, exponent - mant_bits);
exponent -= mant_bits;
@@ -206,15 +266,11 @@ floatformat_to_doublest (const struct floatformat *fmt,
}
/* Negate it if negative. */
- if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
+ if (get_field (ufrom, order, fmt->totalsize, fmt->sign_start, 1))
dto = -dto;
*to = dto;
}
-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
@@ -225,10 +281,14 @@ put_field (unsigned char *data, enum floatformat_byteorders order,
unsigned int cur_byte;
int cur_bitshift;
+ /* Caller must byte-swap words before calling this routine. */
+ gdb_assert (order == floatformat_little || order == floatformat_big);
+
/* Start at the least significant part of the field. */
- if (order == floatformat_little || order == floatformat_littlebyte_bigword)
+ 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)
@@ -249,7 +309,7 @@ put_field (unsigned char *data, enum floatformat_byteorders order,
(stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift);
}
cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little || order == floatformat_littlebyte_bigword)
+ if (order == floatformat_little)
++cur_byte;
else
--cur_byte;
@@ -268,67 +328,20 @@ put_field (unsigned char *data, enum floatformat_byteorders order,
*(data + cur_byte) = ((stuff_to_put >> cur_bitshift)
& ((1 << FLOATFORMAT_CHAR_BIT) - 1));
cur_bitshift += FLOATFORMAT_CHAR_BIT;
- if (order == floatformat_little || order == floatformat_littlebyte_bigword)
+ if (order == floatformat_little)
++cur_byte;
else
--cur_byte;
}
}
-#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
+/* The converse: convert the DOUBLEST *FROM to an extended float and
+ store where TO points. Neither FROM nor TO have any alignment
restrictions. */
-void
-floatformat_from_doublest (CONST struct floatformat *fmt,
- const DOUBLEST *from,
- void *to)
+static void
+convert_doublest_to_floatformat (const struct floatformat *fmt,
+ const DOUBLEST *from, void *to)
{
DOUBLEST dfrom;
int exponent;
@@ -336,48 +349,103 @@ floatformat_from_doublest (CONST struct floatformat *fmt,
unsigned int mant_bits, mant_off;
int mant_bits_left;
unsigned char *uto = (unsigned char *) to;
+ enum floatformat_byteorders order = fmt->byteorder;
+ unsigned char newto[FLOATFORMAT_LARGEST_BYTES];
+
+ if (order != floatformat_little)
+ order = floatformat_big;
+
+ if (order != fmt->byteorder)
+ uto = newto;
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, fmt->byteorder, fmt->totalsize, fmt->exp_start,
+ 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 */
- put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start,
- 32, 1);
- return;
+ /* Be sure it's not infinity, but NaN value is irrel. */
+ put_field (uto, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 1);
+ goto finalize_byteorder;
}
/* If negative, set the sign bit. */
if (dfrom < 0)
{
- put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1);
+ put_field (uto, order, fmt->totalsize, fmt->sign_start, 1, 1);
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, fmt->byteorder, fmt->totalsize, fmt->exp_start,
+ put_field (uto, order, fmt->totalsize, fmt->exp_start,
fmt->exp_len, fmt->exp_nan);
/* Infinity mantissa is all zeroes. */
- put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start,
+ put_field (uto, order, fmt->totalsize, fmt->man_start,
fmt->man_len, 0);
- return;
+ goto finalize_byteorder;
}
#ifdef HAVE_LONG_DOUBLE
- mant = ldfrexp (dfrom, &exponent);
+ mant = frexpl (dfrom, &exponent);
#else
mant = frexp (dfrom, &exponent);
#endif
- put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, fmt->exp_len,
+ 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);
mant_bits_left = fmt->man_len;
@@ -385,6 +453,7 @@ floatformat_from_doublest (CONST struct floatformat *fmt,
while (mant_bits_left > 0)
{
unsigned long mant_long;
+
mant_bits = mant_bits_left < 32 ? mant_bits_left : 32;
mant *= 4294967296.0;
@@ -400,7 +469,15 @@ floatformat_from_doublest (CONST struct floatformat *fmt,
{
mant_long <<= 1;
mant_long &= 0xffffffffL;
- mant_bits -= 1;
+ /* If we are processing the top 32 mantissa bits of a doublest
+ so as to convert to a float value with implied integer bit,
+ we will only be putting 31 of those 32 bits into the
+ final value due to the discarding of the top bit. In the
+ case of a small float value where the number of mantissa
+ bits is less than 32, discarding the top bit does not alter
+ the number of bits we will be adding to the result. */
+ if (mant_bits == 32)
+ mant_bits -= 1;
}
if (mant_bits < 32)
@@ -410,67 +487,87 @@ floatformat_from_doublest (CONST struct floatformat *fmt,
mant_long >>= 32 - mant_bits;
}
- put_field (uto, fmt->byteorder, fmt->totalsize,
+ put_field (uto, order, fmt->totalsize,
mant_off, mant_bits, mant_long);
mant_off += mant_bits;
mant_bits_left -= mant_bits;
}
- if (fmt->byteorder == floatformat_littlebyte_bigword)
- {
- int count;
- unsigned char *swaplow = uto;
- unsigned char *swaphigh = uto + 4;
- unsigned char tmp;
- for (count = 0; count < 4; count++)
- {
- tmp = *swaplow;
- *swaplow++ = *swaphigh;
- *swaphigh++ = tmp;
- }
- }
+ finalize_byteorder:
+ /* Do we need to byte-swap the words in the result? */
+ if (order != fmt->byteorder)
+ floatformat_normalize_byteorder (fmt, newto, to);
}
/* Check if VAL (which is assumed to be a floating point number whose
format is described by FMT) is negative. */
int
-floatformat_is_negative (const struct floatformat *fmt, char *val)
+floatformat_is_negative (const struct floatformat *fmt,
+ const bfd_byte *uval)
{
- unsigned char *uval = (unsigned char *) val;
+ enum floatformat_byteorders order;
+ unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES];
+
+ gdb_assert (fmt != NULL);
+ gdb_assert (fmt->totalsize
+ <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
- return get_field (uval, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1);
+ /* 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)
+ uval = newfrom;
+
+ return get_field (uval, order, fmt->totalsize, fmt->sign_start, 1);
}
/* Check if VAL is "not a number" (NaN) for FMT. */
-int
-floatformat_is_nan (const struct floatformat *fmt, char *val)
+enum float_kind
+floatformat_classify (const struct floatformat *fmt,
+ const bfd_byte *uval)
{
- unsigned char *uval = (unsigned char *) val;
long exponent;
unsigned long mant;
unsigned int mant_bits, mant_off;
int mant_bits_left;
+ enum floatformat_byteorders order;
+ unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES];
+ int mant_zero;
+
+ gdb_assert (fmt != NULL);
+ gdb_assert (fmt->totalsize
+ <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
- if (! fmt->exp_nan)
- return 0;
+ /* 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;
- exponent = get_field (uval, fmt->byteorder, fmt->totalsize,
- fmt->exp_start, fmt->exp_len);
+ order = floatformat_normalize_byteorder (fmt, uval, newfrom);
- if (exponent != fmt->exp_nan)
- return 0;
+ if (order != fmt->byteorder)
+ uval = newfrom;
+
+ exponent = get_field (uval, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len);
mant_bits_left = fmt->man_len;
mant_off = fmt->man_start;
+ mant_zero = 1;
while (mant_bits_left > 0)
{
mant_bits = min (mant_bits_left, 32);
- mant = get_field (uval, fmt->byteorder, fmt->totalsize,
- mant_off, mant_bits);
+ mant = get_field (uval, order, fmt->totalsize, mant_off, mant_bits);
/* If there is an explicit integer bit, mask it off. */
if (mant_off == fmt->man_start
@@ -478,21 +575,49 @@ floatformat_is_nan (const struct floatformat *fmt, char *val)
mant &= ~(1 << (mant_bits - 1));
if (mant)
- return 1;
+ {
+ mant_zero = 0;
+ break;
+ }
mant_off += mant_bits;
mant_bits_left -= mant_bits;
}
- return 0;
+ /* If exp_nan is not set, assume that inf, NaN, and subnormals are not
+ supported. */
+ if (! fmt->exp_nan)
+ {
+ if (mant_zero)
+ return float_zero;
+ else
+ return float_normal;
+ }
+
+ if (exponent == 0 && !mant_zero)
+ return float_subnormal;
+
+ if (exponent == fmt->exp_nan)
+ {
+ if (mant_zero)
+ return float_infinite;
+ else
+ return float_nan;
+ }
+
+ if (mant_zero)
+ return float_zero;
+
+ return float_normal;
}
/* Convert the mantissa of VAL (which is assumed to be a floating
point number whose format is described by FMT) into a hexadecimal
and store it in a static string. Return a pointer to that string. */
-char *
-floatformat_mantissa (const struct floatformat *fmt, char *val)
+const char *
+floatformat_mantissa (const struct floatformat *fmt,
+ const bfd_byte *val)
{
unsigned char *uval = (unsigned char *) val;
unsigned long mant;
@@ -500,6 +625,31 @@ floatformat_mantissa (const struct floatformat *fmt, char *val)
int mant_bits_left;
static char res[50];
char buf[9];
+ int len;
+ enum floatformat_byteorders order;
+ unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES];
+
+ gdb_assert (fmt != NULL);
+ 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)
+ uval = newfrom;
+
+ if (! fmt->exp_nan)
+ return 0;
/* Make sure we have enough room to store the mantissa. */
gdb_assert (sizeof res > ((fmt->man_len + 7) / 8) * 2);
@@ -508,20 +658,19 @@ floatformat_mantissa (const struct floatformat *fmt, char *val)
mant_bits_left = fmt->man_len;
mant_bits = (mant_bits_left % 32) > 0 ? mant_bits_left % 32 : 32;
- mant = get_field (uval, fmt->byteorder, fmt->totalsize,
- mant_off, mant_bits);
+ mant = get_field (uval, order, fmt->totalsize, mant_off, mant_bits);
- sprintf (res, "%lx", mant);
+ len = xsnprintf (res, sizeof res, "%lx", mant);
mant_off += mant_bits;
mant_bits_left -= mant_bits;
-
+
while (mant_bits_left > 0)
{
- mant = get_field (uval, fmt->byteorder, fmt->totalsize,
- mant_off, 32);
+ mant = get_field (uval, order, fmt->totalsize, mant_off, 32);
- sprintf (buf, "%08lx", mant);
+ xsnprintf (buf, sizeof buf, "%08lx", mant);
+ gdb_assert (len + strlen (buf) <= sizeof res);
strcat (res, buf);
mant_off += 32;
@@ -531,99 +680,246 @@ floatformat_mantissa (const struct floatformat *fmt, char *val)
return res;
}
-
-/* Extract a floating-point number from a target-order byte-stream at ADDR.
- Returns the value as type DOUBLEST.
-
- 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. */
+/* Convert TO/FROM target to the hosts DOUBLEST floating-point format.
+
+ 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. 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);
+}
-DOUBLEST
-extract_floating (const void *addr, int len)
+void
+floatformat_to_doublest (const struct floatformat *fmt,
+ const void *in, DOUBLEST *out)
{
- DOUBLEST dretval;
+ gdb_assert (fmt != NULL);
- if (len * TARGET_CHAR_BIT == TARGET_FLOAT_BIT)
+ if (fmt == host_float_format)
{
- if (HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT)
- {
- float retval;
+ float val = 0;
- memcpy (&retval, addr, sizeof (retval));
- return retval;
- }
- else
- floatformat_to_doublest (TARGET_FLOAT_FORMAT, addr, &dretval);
+ memcpy (&val, in, floatformat_totalsize_bytes (fmt));
+ *out = val;
}
- else if (len * TARGET_CHAR_BIT == TARGET_DOUBLE_BIT)
+ else if (fmt == host_double_format)
{
- if (HOST_DOUBLE_FORMAT == TARGET_DOUBLE_FORMAT)
- {
- double retval;
+ double val = 0;
- memcpy (&retval, addr, sizeof (retval));
- return retval;
- }
- else
- floatformat_to_doublest (TARGET_DOUBLE_FORMAT, addr, &dretval);
+ memcpy (&val, in, floatformat_totalsize_bytes (fmt));
+ *out = val;
}
- else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
+ else if (fmt == host_long_double_format)
{
- if (HOST_LONG_DOUBLE_FORMAT == TARGET_LONG_DOUBLE_FORMAT)
- {
- DOUBLEST retval;
+ long double val = 0;
- memcpy (&retval, addr, sizeof (retval));
- return retval;
- }
- else
- floatformat_to_doublest (TARGET_LONG_DOUBLE_FORMAT, addr, &dretval);
+ memcpy (&val, in, floatformat_totalsize_bytes (fmt));
+ *out = val;
}
else
- {
- error ("Can't deal with a floating point number of %d bytes.", len);
- }
-
- return dretval;
+ convert_floatformat_to_doublest (fmt, in, out);
}
void
-store_floating (void *addr, int len, DOUBLEST val)
+floatformat_from_doublest (const struct floatformat *fmt,
+ const DOUBLEST *in, void *out)
{
- if (len * TARGET_CHAR_BIT == TARGET_FLOAT_BIT)
+ gdb_assert (fmt != NULL);
+
+ if (fmt == host_float_format)
{
- if (HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT)
- {
- float floatval = val;
+ float val = *in;
- memcpy (addr, &floatval, sizeof (floatval));
- }
- else
- floatformat_from_doublest (TARGET_FLOAT_FORMAT, &val, addr);
+ memcpy (out, &val, floatformat_totalsize_bytes (fmt));
}
- else if (len * TARGET_CHAR_BIT == TARGET_DOUBLE_BIT)
+ else if (fmt == host_double_format)
{
- if (HOST_DOUBLE_FORMAT == TARGET_DOUBLE_FORMAT)
- {
- double doubleval = val;
+ double val = *in;
- memcpy (addr, &doubleval, sizeof (doubleval));
- }
- else
- floatformat_from_doublest (TARGET_DOUBLE_FORMAT, &val, addr);
+ memcpy (out, &val, floatformat_totalsize_bytes (fmt));
}
- else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
+ else if (fmt == host_long_double_format)
{
- if (HOST_LONG_DOUBLE_FORMAT == TARGET_LONG_DOUBLE_FORMAT)
- memcpy (addr, &val, sizeof (val));
- else
- floatformat_from_doublest (TARGET_LONG_DOUBLE_FORMAT, &val, addr);
+ long double val = *in;
+
+ memcpy (out, &val, floatformat_totalsize_bytes (fmt));
+ }
+ else
+ convert_doublest_to_floatformat (fmt, in, out);
+}
+
+
+/* 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;
+}
+
+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)
+ fmt = TYPE_FLOATFORMAT (type)[gdbarch_byte_order (gdbarch)];
+ else
+ fmt = floatformat_from_length (gdbarch, TYPE_LENGTH (type));
+
+ gdb_assert (TYPE_LENGTH (type) >= floatformat_totalsize_bytes (fmt));
+ return fmt;
+}
+
+/* Extract a floating-point number of type TYPE from a target-order
+ byte-stream at ADDR. Returns the value as type DOUBLEST. */
+
+DOUBLEST
+extract_typed_floating (const void *addr, const struct type *type)
+{
+ const struct floatformat *fmt = floatformat_from_type (type);
+ DOUBLEST retval;
+
+ floatformat_to_doublest (fmt, addr, &retval);
+ return retval;
+}
+
+/* Store VAL as a floating-point number of type TYPE to a target-order
+ byte-stream at ADDR. */
+
+void
+store_typed_floating (void *addr, const struct type *type, DOUBLEST val)
+{
+ 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
+ longer than the actual underlying floating-point format. Perhaps
+ we should store a fixed bitpattern in those remaining bytes,
+ instead of zero, or perhaps we shouldn't touch those remaining
+ bytes at all.
+
+ NOTE: cagney/2001-10-28: With the way things currently work, it
+ isn't a good idea to leave the end bits undefined. This is
+ because GDB writes out the entire sizeof() bits of the
+ floating-point type even though the value might only be stored
+ in, and the target processor may only refer to, the first N <
+ TYPE_LENGTH (type) bits. If the end of the buffer wasn't
+ initialized, GDB would write undefined data to the target. An
+ errant program, refering to that undefined data, would then
+ become non-deterministic.
+
+ See also the function convert_typed_floating below. */
+ memset (addr, 0, TYPE_LENGTH (type));
+
+ floatformat_from_doublest (fmt, &val, addr);
+}
+
+/* Convert a floating-point number of type FROM_TYPE from a
+ target-order byte-stream at FROM to a floating-point number of type
+ TO_TYPE, and store it to a target-order byte-stream at TO. */
+
+void
+convert_typed_floating (const void *from, const struct type *from_type,
+ void *to, const struct type *to_type)
+{
+ const struct floatformat *from_fmt = floatformat_from_type (from_type);
+ const struct floatformat *to_fmt = floatformat_from_type (to_type);
+
+ if (from_fmt == NULL || to_fmt == NULL)
+ {
+ /* If we don't know the floating-point format of FROM_TYPE or
+ TO_TYPE, there's not much we can do. We might make the
+ assumption that if the length of FROM_TYPE and TO_TYPE match,
+ their floating-point format would match too, but that
+ assumption might be wrong on targets that support
+ floating-point types that only differ in endianness for
+ example. So we warn instead, and zero out the target buffer. */
+ warning (_("Can't convert floating-point number to desired type."));
+ memset (to, 0, TYPE_LENGTH (to_type));
+ }
+ else if (from_fmt == to_fmt)
+ {
+ /* We're in business. The floating-point format of FROM_TYPE
+ and TO_TYPE match. However, even though the floating-point
+ format matches, the length of the type might still be
+ different. Make sure we don't overrun any buffers. See
+ 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)));
}
else
{
- error ("Can't deal with a floating point number of %d bytes.", len);
+ /* The floating-point types don't match. The best we can do
+ (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_to_doublest (from_fmt, from, &d);
+ floatformat_from_doublest (to_fmt, &d, to);
}
}