diff options
Diffstat (limited to 'gcc/flow.c')
| -rw-r--r-- | gcc/flow.c | 65 |
1 files changed, 65 insertions, 0 deletions
@@ -9466,6 +9466,71 @@ flow_loop_nodes_find (header, latch, nodes) return num_nodes; } +/* Compute reverse top sort order */ +void +flow_reverse_top_sort_order_compute (rts_order) + int *rts_order; +{ + edge *stack; + int sp; + int postnum = 0; + sbitmap visited; + + /* Allocate stack for back-tracking up CFG. */ + stack = (edge *) xmalloc ((n_basic_blocks + 1) * sizeof (edge)); + sp = 0; + + /* Allocate bitmap to track nodes that have been visited. */ + visited = sbitmap_alloc (n_basic_blocks); + + /* None of the nodes in the CFG have been visited yet. */ + sbitmap_zero (visited); + + /* Push the first edge on to the stack. */ + stack[sp++] = ENTRY_BLOCK_PTR->succ; + + while (sp) + { + edge e; + basic_block src; + basic_block dest; + + /* Look at the edge on the top of the stack. */ + e = stack[sp - 1]; + src = e->src; + dest = e->dest; + + /* Check if the edge destination has been visited yet. */ + if (dest != EXIT_BLOCK_PTR && ! TEST_BIT (visited, dest->index)) + { + /* Mark that we have visited the destination. */ + SET_BIT (visited, dest->index); + + if (dest->succ) + { + /* Since the DEST node has been visited for the first + time, check its successors. */ + stack[sp++] = dest->succ; + } + else + rts_order[postnum++] = dest->index; + } + else + { + if (! e->succ_next && src != ENTRY_BLOCK_PTR) + rts_order[postnum++] = src->index; + + if (e->succ_next) + stack[sp - 1] = e->succ_next; + else + sp--; + } + } + + free (stack); + sbitmap_free (visited); +} + /* Compute the depth first search order and store in the array DFS_ORDER if non-zero, marking the nodes visited in VISITED. If RC_ORDER is non-zero, return the reverse completion number for each |