Diagnostic 13398: Default vector length for function 'xxxx' is 1 and therefore invalid. A valid vector length needs to be explicitly specified.

Cause:

This diagnostic message is emitted when the vectorlength is assumed as 1. The developer is expected to explicitly specify a vector length in this case.  Below is an example for this scenario.


Examples:

__declspec(vector)
double _Complex foo(){
  return 1;
}


$ icc example2.c -c -vec-report2 -std=c99
error #13398: Default vector length for function 'foo' is 1 and therefore invalid. A valid vector length needs to be explicitly specified.

 

For more complete information about compiler optimizations, see our Optimization Notice.