#include "floatformat.h"
#include "gdb_assert.h"
#include "gdb_string.h"
+#include "gdbtypes.h"
#include <math.h> /* ldexp */
/* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not
floatformat_is_negative (const struct floatformat *fmt, char *val)
{
unsigned char *uval = (unsigned char *) val;
-
+ gdb_assert (fmt != NULL);
return get_field (uval, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1);
}
unsigned int mant_bits, mant_off;
int mant_bits_left;
+ gdb_assert (fmt != NULL);
+
if (! fmt->exp_nan)
return 0;
char buf[9];
/* Make sure we have enough room to store the mantissa. */
+ gdb_assert (fmt != NULL);
gdb_assert (sizeof res > ((fmt->man_len + 7) / 8) * 2);
mant_off = fmt->man_start;
return res;
}
-
\f
/* Convert TO/FROM target to the hosts DOUBLEST floating-point format.
}
\f
-/* Extract/store a floating-point number from a target-order
- byte-stream at ADDR. Returns the value as type DOUBLEST. */
+/* Return a floating-point format for a floating-point variable of
+ length LEN. Return NULL, if no suitable floating-point format
+ could be found.
-DOUBLEST
-extract_floating (const void *addr, int len)
+ 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. */
+
+const struct floatformat *
+floatformat_from_length (int len)
{
- DOUBLEST dretval;
if (len * TARGET_CHAR_BIT == TARGET_FLOAT_BIT)
- {
- floatformat_to_doublest (TARGET_FLOAT_FORMAT, addr, &dretval);
- }
+ return TARGET_FLOAT_FORMAT;
else if (len * TARGET_CHAR_BIT == TARGET_DOUBLE_BIT)
- {
- floatformat_to_doublest (TARGET_DOUBLE_FORMAT, addr, &dretval);
- }
+ return TARGET_DOUBLE_FORMAT;
else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
- {
- floatformat_to_doublest (TARGET_LONG_DOUBLE_FORMAT, addr, &dretval);
- }
+ return TARGET_LONG_DOUBLE_FORMAT;
+
+ return NULL;
+}
+
+const struct floatformat *
+floatformat_from_type (const struct type *type)
+{
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+ if (TYPE_FLOATFORMAT (type) != NULL)
+ return TYPE_FLOATFORMAT (type);
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. */
+
+DOUBLEST
+extract_floating (const void *addr, int len)
+{
+ const struct floatformat *fmt = floatformat_from_length (len);
+ DOUBLEST val;
+
+ if (fmt == NULL)
{
- error ("Can't deal with a floating point number of %d bytes.", len);
+ warning ("Can't store a floating-point number of %d bytes.", len);
+ return NAN;
}
- return dretval;
+
+ floatformat_to_doublest (fmt, addr, &val);
+ return val;
}
+/* Store VAL as a floating-point number of length LEN to a
+ target-order byte-stream at ADDR. */
+
void
store_floating (void *addr, int len, DOUBLEST val)
{
- if (len * TARGET_CHAR_BIT == TARGET_FLOAT_BIT)
- {
- floatformat_from_doublest (TARGET_FLOAT_FORMAT, &val, addr);
- }
- else if (len * TARGET_CHAR_BIT == TARGET_DOUBLE_BIT)
+ const struct floatformat *fmt = floatformat_from_length (len);
+
+ if (fmt == NULL)
{
- floatformat_from_doublest (TARGET_DOUBLE_FORMAT, &val, addr);
+ warning ("Can't store a floating-point number of %d bytes.", len);
+ memset (addr, 0, len);
+ return;
}
- else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
- {
- floatformat_from_doublest (TARGET_LONG_DOUBLE_FORMAT, &val, addr);
+
+ floatformat_from_doublest (fmt, &val, addr);
+}
+
+/* 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)
+{
+ DOUBLEST retval;
+
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+
+ if (TYPE_FLOATFORMAT (type) == NULL)
+ return extract_floating (addr, TYPE_LENGTH (type));
+
+ floatformat_to_doublest (TYPE_FLOATFORMAT (type), 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)
+{
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+
+ /* 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(<floating>) 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));
+
+ if (TYPE_FLOATFORMAT (type) == NULL)
+ store_floating (addr, TYPE_LENGTH (type), val);
+ else
+ floatformat_from_doublest (TYPE_FLOATFORMAT (type), &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);
+
+ 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
+ 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
+ (aport 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);
}
}
projects / deliverable / binutils-gdb.git / blobdiff