Re: Vectorizer question

[Tim Prince]

On 5/16/2012 4:01 PM, Iyer, Balaji V wrote:
Hello Everyone,
        I have a question regarding the vectorizer. In the following code 
below...
Int func (int x, int y)
{
        If (x==y)
                Return (x+y);
        Else
                Return (x-y);
}

If we force the x and y to be vectors of vectorlength 4, then will the 
if-statement get a vector of booleans or does it get 1 boolean that compares 2 
very large values? I guess another way to ask is that, will it logically break 
it up into 4 if-statements or just 1?

Any help is greatly appreciated!

Thanks,

Balaji V. Iyer.

PS. Please CC me in response  so that I can get to it quickly.
Is this about vector extensions to C, or about other languages such as 
C++ or Fortran?  In Fortran, it's definitely an array of logical, in the 
case where the compiler can't optimize it away.  This would more likely 
be written
  return x==y ? x+y : x-y;

--
Tim Prince