diff options
Diffstat (limited to 'gcc/tree-ssa-threadedge.c')
| -rw-r--r-- | gcc/tree-ssa-threadedge.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c index 7164122..451dc2e 100644 --- a/gcc/tree-ssa-threadedge.c +++ b/gcc/tree-ssa-threadedge.c @@ -553,6 +553,24 @@ simplify_control_stmt_condition (edge e, || !is_gimple_min_invariant (cached_lhs)) cached_lhs = (*simplify) (dummy_cond, stmt); + /* If we were just testing that an integral type was != 0, and that + failed, just return the first operand. This gives the FSM code a + chance to optimize the path. */ + if (cached_lhs == NULL + && cond_code == NE_EXPR) + { + /* Recover the original operands. They may have been simplified + using context sensitive equivalences. Those context sensitive + equivalences may not be valid on paths found by the FSM optimizer. */ + tree op0 = gimple_cond_lhs (stmt); + tree op1 = gimple_cond_rhs (stmt); + + if (INTEGRAL_TYPE_P (TREE_TYPE (op0)) + && TREE_CODE (op0) == SSA_NAME + && integer_zerop (op1)) + return op0; + } + return cached_lhs; } @@ -974,6 +992,21 @@ fsm_find_control_statement_thread_paths (tree expr, return; } + /* Make sure we haven't already visited any of the nodes in + NEXT_PATH. Don't add them here to avoid pollution. */ + for (unsigned int i = 0; i < next_path->length () - 1; i++) + { + if (visited_bbs->contains ((*next_path)[i])) + { + vec_free (next_path); + return; + } + } + + /* Now add the nodes to VISISTED_BBS. */ + for (unsigned int i = 0; i < next_path->length () - 1; i++) + visited_bbs->add ((*next_path)[i]); + /* Append all the nodes from NEXT_PATH to PATH. */ vec_safe_splice (path, next_path); next_path_length = next_path->length (); |