Problem supporting char and short int

[Prashant Purohit]

Hi Venkataramanan,

    Thanks for the quick reply.

    I tried with doing what you mentioned. But, still getting same assembly
output ( i.e. extra load and store instruction ).

Thanks & Regards,
Prashant.




Venkataramanan Kumar-3 wrote:
> 
> Check by including memory constaints  in your extend pattern.
> 
> (define_expand "extendhisi2"
>   [(set (match_operand:SI 0 "register_operand"      "=b,b")
>         (sign_extend:SI
>          (match_operand:HI 1 "nonimmediate_operand" " b,m")))] <==
> memory operand
>   ""
> 
> On Mon, Jan 4, 2010 at 3:09 PM, Prashant Purohit
> <prashantpurohit025@gmail.com> wrote:
>>
>> Hi,
>>  I am trying to port gcc-4.3.0 to a custom architecture. The high level
>> language selected is C.
>> The processor is a RISC processor and all the registers are of 32-bits
>> wide.
>> The integer data type (SImode) is set as 32-bits.
>>
>> I have already completed implementation to support integer data type and
>> it
>> works fine. Now I am trying to support other data types such as char
>> (8-bits), short int (16-bits).
>> I have defined the following things:
>> 1. macros in the .h file:
>> #define LOAD_EXTEND_OP(MODE) SIGN_EXTEND
>>
>> #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE) \
>>  if (GET_MODE_CLASS (MODE) == MODE_INT         \
>>      && GET_MODE_SIZE (MODE) < 4)              \
>>    {                                           \
>>      (MODE) = SImode;                          \
>>    }
>>
>> #define PROMOTE_FUNCTION_MODE(MODE, UNSIGNEDP, TYPE)    \
>>  if ((GET_MODE_CLASS (MODE) == MODE_INT                \
>>       || GET_MODE_CLASS (MODE) == MODE_COMPLEX_INT)    \
>>      && GET_MODE_SIZE (MODE) < 4)                      \
>>    (MODE) = SImode;
>>
>> 2. md patterns for zero_extend and extend patterns, movqi and movhi.
>>
>> The gcc builds successfully and also cc1 compiles the following C code.
>> But
>> you can see that the generated assembly has bugs.
>>
>> C code:
>>   void main()
>> {
>>   short int c;
>>   int b;
>>
>>   b = c;
>>
>> }
>>
>> generated .s looks something like :
>>
>> ...function prologue..
>> loadHI Reg1, (frame_pointer, #-18)
>> storeHI Reg1,[frame_pointer, #-28]
>> loadSI  Reg2, [frame_pointer, #-28]
>> ashiftleft   Reg1,Reg2,#16
>> ashiftright     Reg1,Reg1,#16
>> storeSI Reg1,[frame_pointer, #-16]
>> ...function epilogue
>>
>>
>> expected .s is:
>> ...function prologue..
>> loadHI Reg1, (frame_pointer, #-18)
>> storeSI Reg1,[frame_pointer, #-16]
>> ...function epilogue
>>
>> I am not able to find out why extra load, store and shift instructions
>> are
>> generated.
>>
>> -Rajeshwari
>> --
>> View this message in context:
>> http://old.nabble.com/Problem-supporting-char-and-short-int-tp27010666p27010666.html
>> Sent from the gcc - Help mailing list archive at Nabble.com.
>>
>>
> 
> 

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