Re: [patch, fortran] Index interchange for FORALL and DO CONCURRENT

[Thomas Koenig]

Hi Bernhard,

Regression-tested. OK for trunk?

s/shoud/should/; s/acessed/accessed/; s/indces/indices/;

Fixed.

why are struct ind_type "n" and "num" int and not unsigned int?

I tend not to use signed variables unless the special overflow
semantics are required.  I like Fortran, which doesn't have
unsigned ints.

Can't you scan the original dump for something characteristic?

I'd need a dejagnu multiline regexp, to reject


       i.7 = 1;
        count.10 = 512;
        while (1)
          {
            if (ANNOTATE_EXPR <count.10 <= 0, ivdep>) goto L.4;
            j.6 = 1;
            count.9 = 512;
            while (1)
              {
                if (ANNOTATE_EXPR <count.9 <= 0, ivdep>) goto L.3;

while accepting

       k.7 = 1;
        count.10 = 512;
        while (1)
          {
            if (ANNOTATE_EXPR <count.10 <= 0, ivdep>) goto L.4;
            j.6 = 1;
            count.9 = 512;
            while (1)
              {
                if (ANNOTATE_EXPR <count.9 <= 0, ivdep>) goto L.3;
                i.5 = 1;
                count.8 = 512;

and not being confused by

                    if (ANNOTATE_EXPR <count.8 <= 0, ivdep>) goto L.2;
                    (*(real(kind=4)[0:] * restrict) c.data)[((c.offset 
+ (integer(kind=8)) k.5 * c.dim[2].stride) + (integer(kind=8)) j.6 * 
c.dim[1].stride) + (integer(kind=8)) i.7] = (*(real(kind=4)[0:] * 
restrict) a.data)[((a.offset + (integer(kind=8)) k.5 * a.dim[2].stride) 
+ (integer(kind=8)) j.6 * a.dim[1].stride) + (integer(kind=8)) i.7] + 
(*(real(kind=4)[0:] * restrict) b.data)[((b.offset + (integer(kind=8)) 
k.5 * b.dim[2].stride) + (integer(kind=8)) j.6 * b.dim[1].stride) + 
(integer(kind=8)) i.7];
                    L.1:;
                    k.5 = k.5 + 1;
                    count.8 = count.8 + -1;
                  }
                L.2:;
                j.6 = j.6 + 1;
                count.9 = count.9 + -1;
              }
            L.3:;
            i.7 = i.7 + 1;
            count.10 = count.10 + -1;
          }
        L.4:;
      }

... but keep that easy enough to understand so people can
change it later if somebody changes something in trans-*.
I gave up.

Or maybe emit diagnostics into the frontend optimize dump file and scan
that?

If we could check the Fortran tree dumps with dejagnu, that would be
doable. Unfortunately, we don't have that in place.

This would be the difference between

DO CONCURRENT test_do_speed:k 1:512:1,test_do_speed:j 
1:512:1,test_do_speed:i 1:512:1()

and

DO CONCURRENT test_do_speed:i 1:512:1,test_do_speed:j 
1:512:1,test_do_speed:k 1:512:1()

Just about the only way I can think of is to add a warning
option if something is actually interchanged. Might be worth
doing anyway, but I would like not to add too many -W options.

-fopt-info would be nice to have here (PR 66576). I had a
preliminary look at what it does for gcc, but after a look
at the source, I decided that this was not really self-explanatory
and that I'd rather do other things :-)

Regards

        Thomas