+/* Basic byte-swapping routines. GDB has needed these for a long time...
+ All extract a target-format integer at ADDR which is LEN bytes long. */
+
+#if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8
+ /* 8 bit characters are a pretty safe assumption these days, so we
+ assume it throughout all these swapping routines. If we had to deal with
+ 9 bit characters, we would need to make len be in bits and would have
+ to re-write these routines... */
+ you lose
+#endif
+
+LONGEST
+extract_signed_integer (addr, len)
+ PTR addr;
+ int len;
+{
+ LONGEST retval;
+ unsigned char *p;
+ unsigned char *startaddr = (unsigned char *)addr;
+ unsigned char *endaddr = startaddr + len;
+
+ if (len > sizeof (LONGEST))
+ error ("\
+That operation is not available on integers of more than %d bytes.",
+ sizeof (LONGEST));
+
+ /* Start at the most significant end of the integer, and work towards
+ the least significant. */
+#if TARGET_BYTE_ORDER == BIG_ENDIAN
+ p = startaddr;
+#else
+ p = endaddr - 1;
+#endif
+ /* Do the sign extension once at the start. */
+ retval = ((LONGEST)*p ^ 0x80) - 0x80;
+#if TARGET_BYTE_ORDER == BIG_ENDIAN
+ for (++p; p < endaddr; ++p)
+#else
+ for (--p; p >= startaddr; --p)
+#endif
+ {
+ retval = (retval << 8) | *p;
+ }
+ return retval;
+}
+
+unsigned LONGEST
+extract_unsigned_integer (addr, len)
+ PTR addr;
+ int len;
+{
+ unsigned LONGEST retval;
+ unsigned char *p;
+ unsigned char *startaddr = (unsigned char *)addr;
+ unsigned char *endaddr = startaddr + len;
+
+ if (len > sizeof (unsigned LONGEST))
+ error ("\
+That operation is not available on integers of more than %d bytes.",
+ sizeof (unsigned LONGEST));
+
+ /* Start at the most significant end of the integer, and work towards
+ the least significant. */
+ retval = 0;
+#if TARGET_BYTE_ORDER == BIG_ENDIAN
+ for (p = startaddr; p < endaddr; ++p)
+#else
+ for (p = endaddr - 1; p >= startaddr; --p)
+#endif
+ {
+ retval = (retval << 8) | *p;
+ }
+ return retval;
+}
+
+CORE_ADDR
+extract_address (addr, len)
+ PTR addr;
+ int len;
+{
+ /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
+ whether we want this to be true eventually. */
+ return extract_unsigned_integer (addr, len);
+}
+
+void
+store_signed_integer (addr, len, val)
+ PTR addr;
+ int len;
+ LONGEST val;
+{
+ unsigned char *p;
+ unsigned char *startaddr = (unsigned char *)addr;
+ unsigned char *endaddr = startaddr + len;
+
+ /* Start at the least significant end of the integer, and work towards
+ the most significant. */
+#if TARGET_BYTE_ORDER == BIG_ENDIAN
+ for (p = endaddr - 1; p >= startaddr; --p)
+#else
+ for (p = startaddr; p < endaddr; ++p)
+#endif
+ {
+ *p = val & 0xff;
+ val >>= 8;
+ }
+}
+
+void
+store_unsigned_integer (addr, len, val)
+ PTR addr;
+ int len;
+ unsigned LONGEST val;
+{
+ unsigned char *p;
+ unsigned char *startaddr = (unsigned char *)addr;
+ unsigned char *endaddr = startaddr + len;
+
+ /* Start at the least significant end of the integer, and work towards
+ the most significant. */
+#if TARGET_BYTE_ORDER == BIG_ENDIAN
+ for (p = endaddr - 1; p >= startaddr; --p)
+#else
+ for (p = startaddr; p < endaddr; ++p)
+#endif
+ {
+ *p = val & 0xff;
+ val >>= 8;
+ }
+}
+
+void
+store_address (addr, len, val)
+ PTR addr;
+ int len;
+ CORE_ADDR val;
+{
+ /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
+ whether we want this to be true eventually. */
+ store_unsigned_integer (addr, len, (LONGEST)val);
+}
+\f
+/* Swap LEN bytes at BUFFER between target and host byte-order. This is
+ the wrong way to do byte-swapping because it assumes that you have a way
+ to have a host variable of exactly the right size. Once extract_floating
+ and store_floating have been fixed, this can go away. */
+#if TARGET_BYTE_ORDER == HOST_BYTE_ORDER
+#define SWAP_TARGET_AND_HOST(buffer,len)
+#else /* Target and host byte order differ. */
+#define SWAP_TARGET_AND_HOST(buffer,len) \
+ { \
+ char tmp; \
+ char *p = (char *)(buffer); \
+ char *q = ((char *)(buffer)) + len - 1; \
+ for (; p < q; p++, q--) \
+ { \
+ tmp = *q; \
+ *q = *p; \
+ *p = tmp; \
+ } \
+ }
+#endif /* Target and host byte order differ. */
+
+/* There are many problems with floating point cross-debugging.
+
+ 1. These routines only handle byte-swapping, not conversion of
+ formats. So if host is IEEE floating and target is VAX floating,
+ or vice-versa, it loses. This means that we can't (yet) use these
+ routines for extendeds. Extendeds are handled by
+ REGISTER_CONVERTIBLE. What we want is a fixed version of
+ ieee-float.c (the current version can't deal with single or double,
+ and I suspect it is probably broken for some extendeds too).
+
+ 2. We can't deal with it if there is more than one floating point
+ format in use. This has to be fixed at the unpack_double level.
+
+ 3. We probably should have a LONGEST_DOUBLE or DOUBLEST or whatever
+ we want to call it which is long double where available. */
+
+double
+extract_floating (addr, len)
+ PTR addr;
+ int len;
+{
+ if (len == sizeof (float))
+ {
+ float retval;
+ memcpy (&retval, addr, sizeof (retval));
+ SWAP_TARGET_AND_HOST (&retval, sizeof (retval));
+ return retval;
+ }
+ else if (len == sizeof (double))
+ {
+ double retval;
+ memcpy (&retval, addr, sizeof (retval));
+ SWAP_TARGET_AND_HOST (&retval, sizeof (retval));
+ return retval;
+ }
+ else
+ {
+ error ("Can't deal with a floating point number of %d bytes.", len);
+ }
+}
+
+void
+store_floating (addr, len, val)
+ PTR addr;
+ int len;
+ double val;
+{
+ if (len == sizeof (float))
+ {
+ float floatval = val;
+ SWAP_TARGET_AND_HOST (&floatval, sizeof (floatval));
+ memcpy (addr, &floatval, sizeof (floatval));
+ }
+ else if (len == sizeof (double))
+ {
+ SWAP_TARGET_AND_HOST (&val, sizeof (val));
+ memcpy (addr, &val, sizeof (val));
+ }
+ else
+ {
+ error ("Can't deal with a floating point number of %d bytes.", len);
+ }
+}
+\f
projects / binutils.git / blobdiff