diff options
Diffstat (limited to 'gcc/tree-cfg.c')
| -rw-r--r-- | gcc/tree-cfg.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index afeb4de..2eff754 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -3825,7 +3825,11 @@ tree_forwarder_block_p (basic_block bb) /* Thread jumps over empty statements. This code should _not_ thread over obviously equivalent conditions - as that requires nontrivial updates to the SSA graph. */ + as that requires nontrivial updates to the SSA graph. + + As a precondition, we require that all basic blocks be reachable. + That is, there should be no opportunities left for + delete_unreachable_blocks. */ static bool thread_jumps (void) @@ -3839,18 +3843,14 @@ thread_jumps (void) FOR_EACH_BB (bb) bb_ann (bb)->forwardable = 1; - FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) + FOR_EACH_BB (bb) { edge_iterator ei; - /* Don't waste time on unreachable blocks. */ - if (EDGE_COUNT (bb->preds) == 0) - continue; - - /* Nor on forwarders. */ + /* Don't waste time on forwarders. */ if (tree_forwarder_block_p (bb)) continue; - + /* This block is now part of a forwarding path, mark it as not forwardable so that we can detect loops. This bit will be reset below. */ |