Generate abs target assembly code with saturation behavior

[Shiva Chen]

Hi,

I have a case which will generate abs instructions.

int main(int argc)
 {
    if (argc < 0)
       argc = -(unsigned int)argc;
     return argc;
  }

To my understanding, given that argc=0x80000000 in 32bit int plaform,
the result of (unsigned int)argc is well defined and should be 0x80000000u.
(C99  6.3.1.3 point 2)

And then the result of -0x80000000u should be 0x80000000 because
unsigned operation can never overflow and the value can be
represented by signed integer.
(C99  6.2.5 point 9)

when the case is compiled above -O1,
it would generate abs instruction directly if the target provides
abssi2 naming pattern.

However, if the target's abs have saturation behavior
(i.e  abs (0x80000000) = 0x7fffffff)
then the result will wrong.

My question is
Does the abssi2 semantically assume target abs shouldn't do saturation ?

If the target abs have saturation behavior
How should the target generate abs instruction to avoid the wrong result ?

I noticed that there is ss_abs rtx code.
But it seems there is no ss_abssi2 naming pattern.

Any suggestion?

Thanks in advance.

Shiva