[avr] Fix argument passing for call
Commit Message
When calling function with argument of size more than 8 bytes fails with
an error "That operation is not available on integers of more than 8 bytes.".
avr-gdb considers only 8 bytes (sizeof(long long)) in case of passing the
argument in registers. When the argument is of size more than 8 byte
then the utility function to extract bytes failed with the above error.
Attached a patch fix this issue. This patch includes the fix discussed
here: https://sourceware.org/ml/gdb-patches/2016-02/msg00884.html
(Both fixes are in same function and the earlier is not committed)
Ran the tests for avr-gdb with internal simulators. No new regressions.
If ok, could someone commit please? I do not have commit access.
Regards,
Pitchumani
gdb/ChangeLog
2016-03-01 Pitchumani Sivanupandi<pitchumani.s@atmel.com>
* avr-tdep.c (AVR_LAST_ARG_REGNUM): Define.
(avr_push_dummy_call): Correct last needed argument register.
Write MSB of argument into register and subsequent bytes into
other registers in decreasing order.
Comments
2016-03-01 14:09 GMT+03:00 Pitchumani Sivanupandi <pitchumani.s@atmel.com>:
> When calling function with argument of size more than 8 bytes fails with
> an error "That operation is not available on integers of more than 8 bytes.".
> avr-gdb considers only 8 bytes (sizeof(long long)) in case of passing the
> argument in registers. When the argument is of size more than 8 byte
> then the utility function to extract bytes failed with the above error.
>
> Attached a patch fix this issue. This patch includes the fix discussed
> here: https://sourceware.org/ml/gdb-patches/2016-02/msg00884.html
> (Both fixes are in same function and the earlier is not committed)
>
> Ran the tests for avr-gdb with internal simulators. No new regressions.
>
> If ok, could someone commit please? I do not have commit access.
>
> Regards,
> Pitchumani
>
> gdb/ChangeLog
>
> 2016-03-01 Pitchumani Sivanupandi<pitchumani.s@atmel.com>
>
> * avr-tdep.c (AVR_LAST_ARG_REGNUM): Define.
> (avr_push_dummy_call): Correct last needed argument register.
> Write MSB of argument into register and subsequent bytes into
> other registers in decreasing order.
Committed.
Denis.
@@ -111,6 +111,7 @@ enum
AVR_ARG1_REGNUM = 24, /* Single byte argument */
AVR_ARGN_REGNUM = 25, /* Multi byte argments */
+ AVR_LAST_ARG_REGNUM = 8, /* Last argument register */
AVR_RET1_REGNUM = 24, /* Single byte return value */
AVR_RETN_REGNUM = 25, /* Multi byte return value */
@@ -1298,23 +1299,24 @@ avr_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
const bfd_byte *contents = value_contents (arg);
int len = TYPE_LENGTH (type);
- /* Calculate the potential last register needed. */
- last_regnum = regnum - (len + (len & 1));
+ /* Calculate the potential last register needed.
+ E.g. For length 2, registers regnum and regnum-1 (say 25 and 24)
+ shall be used. So, last needed register will be regnum-1(24). */
+ last_regnum = regnum - (len + (len & 1)) + 1;
/* If there are registers available, use them. Once we start putting
stuff on the stack, all subsequent args go on stack. */
- if ((si == NULL) && (last_regnum >= 8))
+ if ((si == NULL) && (last_regnum >= AVR_LAST_ARG_REGNUM))
{
- ULONGEST val;
-
/* Skip a register for odd length args. */
if (len & 1)
regnum--;
- val = extract_unsigned_integer (contents, len, byte_order);
+ /* Write MSB of argument into register and subsequent bytes in
+ decreasing register numbers. */
for (j = 0; j < len; j++)
regcache_cooked_write_unsigned
- (regcache, regnum--, val >> (8 * (len - j - 1)));
+ (regcache, regnum--, contents[len - j - 1]);
}
/* No registers available, push the args onto the stack. */
else