diff options
Diffstat (limited to 'gcc/lcm.c')
| -rw-r--r-- | gcc/lcm.c | 14 |
1 files changed, 14 insertions, 0 deletions
@@ -269,6 +269,13 @@ compute_laterin (edge_list, earliest, antloc, later, laterin) of the optimistic edge. That will requeue the affected blocks. */ sbitmap_vector_ones (later, num_edges); + /* Note that even though we want an optimistic setting of LATER, we + do not want to be overly optimistic. Consider an outgoing edge from + the entry block. That edge should always have a LATER value the + same as EARLIEST for that edge. */ + for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) + sbitmap_copy (later[(int)e->aux], earliest[(int)e->aux]); + /* Add all the blocks to the worklist. This prevents an early exit from the loop given our optimistic initialization of LATER above. */ for (bb = n_basic_blocks - 1; bb >= 0; bb--) @@ -598,6 +605,13 @@ compute_nearerout (edge_list, farthest, st_avloc, nearer, nearerout) /* We want a maximal solution. */ sbitmap_vector_ones (nearer, num_edges); + /* Note that even though we want an optimistic setting of NEARER, we + do not want to be overly optimistic. Consider an incoming edge to + the exit block. That edge should always have a NEARER value the + same as FARTHEST for that edge. */ + for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next) + sbitmap_copy (nearer[(int)e->aux], farthest[(int)e->aux]); + /* Add all the blocks to the worklist. This prevents an early exit from the loop given our optimistic initialization of NEARER. */ for (bb = 0; bb < n_basic_blocks; bb++) |