diff options
Diffstat (limited to 'gcc/tree-ssa-threadupdate.c')
| -rw-r--r-- | gcc/tree-ssa-threadupdate.c | 48 |
1 files changed, 28 insertions, 20 deletions
diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c index 1dab0f1fab4..045905eceb7 100644 --- a/gcc/tree-ssa-threadupdate.c +++ b/gcc/tree-ssa-threadupdate.c @@ -691,8 +691,7 @@ static bool compute_path_counts (struct redirection_data *rd, ssa_local_info_t *local_info, profile_count *path_in_count_ptr, - profile_count *path_out_count_ptr, - int *path_in_freq_ptr) + profile_count *path_out_count_ptr) { edge e = rd->incoming_edges->e; vec<jump_thread_edge *> *path = THREAD_PATH (e); @@ -700,7 +699,6 @@ compute_path_counts (struct redirection_data *rd, profile_count nonpath_count = profile_count::zero (); bool has_joiner = false; profile_count path_in_count = profile_count::zero (); - int path_in_freq = 0; /* Start by accumulating incoming edge counts to the path's first bb into a couple buckets: @@ -740,7 +738,6 @@ compute_path_counts (struct redirection_data *rd, source block. */ gcc_assert (ein_path->last ()->e == elast); path_in_count += ein->count (); - path_in_freq += EDGE_FREQUENCY (ein); } else if (!ein_path) { @@ -751,10 +748,6 @@ compute_path_counts (struct redirection_data *rd, } } - /* This is needed due to insane incoming frequencies. */ - if (path_in_freq > BB_FREQ_MAX) - path_in_freq = BB_FREQ_MAX; - /* Now compute the fraction of the total count coming into the first path bb that is from the current threading path. */ profile_count total_count = e->dest->count; @@ -843,7 +836,6 @@ compute_path_counts (struct redirection_data *rd, *path_in_count_ptr = path_in_count; *path_out_count_ptr = path_out_count; - *path_in_freq_ptr = path_in_freq; return has_joiner; } @@ -954,7 +946,6 @@ ssa_fix_duplicate_block_edges (struct redirection_data *rd, edge elast = path->last ()->e; profile_count path_in_count = profile_count::zero (); profile_count path_out_count = profile_count::zero (); - int path_in_freq = 0; /* First determine how much profile count to move from original path to the duplicate path. This is tricky in the presence of @@ -963,8 +954,7 @@ ssa_fix_duplicate_block_edges (struct redirection_data *rd, non-joiner case the path_in_count and path_out_count should be the same. */ bool has_joiner = compute_path_counts (rd, local_info, - &path_in_count, &path_out_count, - &path_in_freq); + &path_in_count, &path_out_count); for (unsigned int count = 0, i = 1; i < path->length (); i++) { @@ -2184,7 +2174,6 @@ thread_through_all_blocks (bool may_peel_loop_headers) { bool retval = false; unsigned int i; - bitmap_iterator bi; struct loop *loop; auto_bitmap threaded_blocks; @@ -2288,14 +2277,33 @@ thread_through_all_blocks (bool may_peel_loop_headers) initialize_original_copy_tables (); - /* First perform the threading requests that do not affect - loop structure. */ - EXECUTE_IF_SET_IN_BITMAP (threaded_blocks, 0, i, bi) - { - basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); + /* The order in which we process jump threads can be important. + + Consider if we have two jump threading paths A and B. If the + target edge of A is the starting edge of B and we thread path A + first, then we create an additional incoming edge into B->dest that + we can not discover as a jump threading path on this iteration. + + If we instead thread B first, then the edge into B->dest will have + already been redirected before we process path A and path A will + natually, with no further work, target the redirected path for B. - if (EDGE_COUNT (bb->preds) > 0) - retval |= thread_block (bb, true); + An post-order is sufficient here. Compute the ordering first, then + process the blocks. */ + if (!bitmap_empty_p (threaded_blocks)) + { + int *postorder = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); + unsigned int postorder_num = post_order_compute (postorder, false, false); + for (unsigned int i = 0; i < postorder_num; i++) + { + unsigned int indx = postorder[i]; + if (bitmap_bit_p (threaded_blocks, indx)) + { + basic_block bb = BASIC_BLOCK_FOR_FN (cfun, indx); + retval |= thread_block (bb, true); + } + } + free (postorder); } /* Then perform the threading through loop headers. We start with the |