diff options
Diffstat (limited to 'gcc/gimple-loop-jam.cc')
| -rw-r--r-- | gcc/gimple-loop-jam.cc | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/gcc/gimple-loop-jam.cc b/gcc/gimple-loop-jam.cc index a8a57d3..4f7a6e5 100644 --- a/gcc/gimple-loop-jam.cc +++ b/gcc/gimple-loop-jam.cc @@ -545,11 +545,25 @@ tree_loop_unroll_and_jam (void) /* If the refs are independend there's nothing to do. */ if (DDR_ARE_DEPENDENT (ddr) == chrec_known) continue; + dra = DDR_A (ddr); drb = DDR_B (ddr); - /* Nothing interesting for the self dependencies. */ + + /* Nothing interesting for the self dependencies, except for WAW if + the access function is not affine or constant because we may end + up reordering writes to the same location. */ if (dra == drb) - continue; + { + if (DR_IS_WRITE (dra) + && !DR_ACCESS_FNS (dra).is_empty () + && DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) + { + unroll_factor = 0; + break; + } + else + continue; + } /* Now check the distance vector, for determining a sensible outer unroll factor, and for validity of merging the inner |