[Bug tree-optimization/18441] New: Vectorizer: add a command line for simple vectorizer report

[giovannibajo at libero dot it]

If an user wants to know if vectorization succeeded or not, he has to use -
fdump-tree-vect-details and then grep for some special pattern to find the 
lines that say if loops were vectorized or not.

Such an information can be very useful while developing code, so I think it 
should be easily given. ICC has an option /Qvec_report[=n] to setup a 
diagnostic (equivalent to our inform()), with different verbosity levels. I 
suggest we add something like this to GCC as well.


/Qvec_report[n]  control amount of vectorizer diagnostic information:
            n=0    no diagnostic information
            n=1    indicate vectorized loops (DEFAULT)
            n=2    indicate vectorized/non-vectorized loops
            n=3    indicate vectorized/non-vectorized loops and prohibiting
                   data dependence information
            n=4    indicate non-vectorized loops
            n=5    indicate non-vectorized loops and prohibiting data
                   dependence information


With such an infrastructure, we could also change the vectorizer testsuite not 
to scan the details dump and just do a { dg-inform "VECTORIZED" } (or similar) 
on the line with the loop header.

-- 
           Summary: Vectorizer: add a command line for simple vectorizer
                    report
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: giovannibajo at libero dot it
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18441