[Bug middle-end/49662] [4.7 Regression] FAIL: gcc.dg/graphite/interchange-XX.c

[spop at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49662

--- Comment #2 from Sebastian Pop <spop at gcc dot gnu.org> 2011-07-07 22:40:34 
UTC ---
The loop nest is not perfect, in interchange-15.c:

  for (i = 0; i < N; i++)
    for (j = 0; j < N; j++)
      x[i] += a[j][i];

used to be perfect nest, now we have x[i] read and written in
the outer loop, enough to confuse loop interchange.

Please XFail the testcases, or change them to only have a
scalar reduction:

  for (i = 0; i < N; i++)
    for (j = 0; j < N; j++)
      x += a[j][i];