diff options
Diffstat (limited to 'gcc/tree-loop-distribution.cc')
| -rw-r--r-- | gcc/tree-loop-distribution.cc | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/gcc/tree-loop-distribution.cc b/gcc/tree-loop-distribution.cc index a28470b..8abfa99 100644 --- a/gcc/tree-loop-distribution.cc +++ b/gcc/tree-loop-distribution.cc @@ -949,7 +949,8 @@ copy_loop_before (class loop *loop, bool redirect_lc_phi_defs) edge preheader = loop_preheader_edge (loop); initialize_original_copy_tables (); - res = slpeel_tree_duplicate_loop_to_edge_cfg (loop, NULL, preheader); + res = slpeel_tree_duplicate_loop_to_edge_cfg (loop, single_exit (loop), NULL, + NULL, preheader, NULL, false); gcc_assert (res != NULL); /* When a not last partition is supposed to keep the LC PHIs computed @@ -1574,6 +1575,7 @@ find_single_drs (class loop *loop, struct graph *rdg, const bitmap &partition_st basic_block bb_ld = NULL; basic_block bb_st = NULL; + edge exit = single_exit (loop); if (single_ld) { @@ -1589,6 +1591,14 @@ find_single_drs (class loop *loop, struct graph *rdg, const bitmap &partition_st bb_ld = gimple_bb (DR_STMT (single_ld)); if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb_ld)) return false; + + /* The data reference must also be executed before possibly exiting + the loop as otherwise we'd for example unconditionally execute + memset (ptr, 0, n) which even with n == 0 implies ptr is non-NULL. */ + if (bb_ld != loop->header + && (!exit + || !dominated_by_p (CDI_DOMINATORS, exit->src, bb_ld))) + return false; } if (single_st) @@ -1604,6 +1614,12 @@ find_single_drs (class loop *loop, struct graph *rdg, const bitmap &partition_st bb_st = gimple_bb (DR_STMT (single_st)); if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb_st)) return false; + + /* And before exiting the loop. */ + if (bb_st != loop->header + && (!exit + || !dominated_by_p (CDI_DOMINATORS, exit->src, bb_st))) + return false; } if (single_ld && single_st) |