2008/7/16 Ian Lance Taylor <[EMAIL PROTECTED]>:
> "Mohamed Shafi" <[EMAIL PROTECTED]> writes:
>
>> I am involved in the porting of gcc 4.1.2 for 16 bit target. For this
>> target size of long long is 32bits. For the following code
>>
>> #define VALUE 0x1B4E81B4E81B4DLL
>
> That is not a 32-bit value.
>
>
>> #define AFTER 0x55
>>
>> //void test (int n, long long q, int y);
>> void test (int n, ...);
>>
>> int
>> main ()
>> {
>> test (1, VALUE, AFTER);
>> exit(0);
>> }
>>
>> i find that the machine mode of the arguments of test are HImode,
>> DImode and HImode. When replace function 'test' with normal one
>> instead of varargs i find that the machine modes are HImode, SImode
>> and HImode respectively.
>> My question is even if the function is a vararg function shouldn't the
>> mode of the argument be SImode instead of DImode since long long is
>> only 32bit for the target?
>
> The value is too big for a long long. When you specify the type, gcc
> is forced to convert (I hope you can get a warning for that). When
> you don't specify the type, gcc does not convert. The resulting value
> has a type which can only be expressed using a gcc extension.
So the behavior that i am getting is a proper one.
>
> If you change the TARGET_SCALAR_MODE_SUPPORTED_P hook to reject all
> modes larger than SImode, you may get a different result--probably
> some sort of error.
Yes this is one option that i dint think about. But let me ask you
some thing. for my target when returning structures will use
registers, if its available. So a structure that has size of 16x4 will
be given 4 registers (i.e DImode). So if i use this hook will the
structure returning work properly? I mean will they be broken down
into two 32bit data types?
Shafi
