[Bug tree-optimization/46032] openmp inhibits loop vectorization

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46032

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-10-15 
10:30:42 UTC ---
If I hack PTA to make the omp function not escape IPA-PTA computes

<bb 4>:
  # idx_1 = PHI <idx_11(3), idx_18(6)>
  # PT = { D.2069 }
  D.2112_13 = .omp_data_i_12(D)->pData;
  D.2113_14 = *D.2112_13[idx_1];
  D.2114_15 = .omp_data_i_12(D)->coeff;
  D.2115_16 = D.2113_14 * D.2114_15;
  # PT = { D.2068 }
  D.2116_17 = .omp_data_i_12(D)->results;

thus knows what the pointers point to and we vectorize w/o a runtime
alias check (we still have no idea about alignment though, but that's
probably correct).

Thus it might be worth annotating some of the OMP builtins with
the fnspec attribute.