On Tue, Oct 15, 2013 at 8:04 AM, Nagaraju Mekala <gnuuser....@gmail.com> wrote:
> Hi Ian,
>
> Thanks for the reply.
>
> On Fri, Oct 11, 2013 at 10:31 PM, Ian Lance Taylor <i...@google.com> wrote:
>> On Fri, Oct 11, 2013 at 9:20 AM, Nagaraju Mekala <gnuuser....@gmail.com>
>> wrote:
>>>
>>> I observed that in rs6000 port longcall is implemented by using
>>> CALL_LONG define.
>>> #define CALL_LONG 0x00000008 /* always call indirect */
>>> In the md file they are checking the operand with CALL_LONG
>>> if (INTVAL (operands[3]) & CALL_LONG)
>>> operands[1] = rs6000_longcall_ref (operands[1]);
>>> In my port I dont have suchthing to compare. Can we somehow parse the
>>> tree chain and check the attributes of the functions..
>>
>> Look at init_cumulative_args in rs6000.c to see how CALL_LONG is set
>> based on the function attribute.
>
> I was able to get the function attribute from the init_cumulative_args
> function. I have used the fndecl tree to get the attribute details
> but I have failed to stop generating br instruction. It should print
> bk instruction.
> I was unable to relate the super attribute from init_cumulative_args
> to the branch pattern in md file to generate bk instruction.
> I have intialized a global variable to 1 if super is detected and
> checking the same in my pattern.
> My branch pattern looks like below
> (define_insn "call_int1"
> [(call (mem (match_operand:SI 0 "call_insn_simple_operand" "ri"))
> (match_operand:SI 1 "" "i"))
> (clobber (reg:SI R_RS))]
> ""
> {
> register rtx t = operands[0];
> register rtx t2 = gen_rtx_REG (Pmode,
> GP_REG_FIRST + RETURN_ADDR_REGNUM);
> if (GET_CODE (t) == SYMBOL_REF) {
> if(super_var()) ---------------> Here I am
> checking for global variable
> {
> return "bk\tr1,8\;%#";
> }
> else {
> gen_rtx_CLOBBER (VOIDmode, t2);
> return "br\tr1,%0\;%#";
>
> I observed that init_cumulative_args is called first for all the
> functions once they are done then the above pattern for all the
> instructions are called so my global variable is not useful.
>
> Can you help me how to exactly emit bk instruction from the pattern
> when super function is called.
Again I just have to say: look at the rs6000 port. Look at the rs6000
call instruction. Look at how it decides whether to do a longcall or
not.
Ian
