diff options
Diffstat (limited to 'gcc/tree-ssa-threadedge.c')
| -rw-r--r-- | gcc/tree-ssa-threadedge.c | 33 |
1 files changed, 7 insertions, 26 deletions
diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c index 386aea7..ddd5061 100644 --- a/gcc/tree-ssa-threadedge.c +++ b/gcc/tree-ssa-threadedge.c @@ -566,7 +566,7 @@ simplify_control_stmt_condition (edge e, It is possible to get loops in the SSA_NAME_VALUE chains (consider threading the backedge of a loop where we have - a loop invariant SSA_NAME used in the condition. */ + a loop invariant SSA_NAME used in the condition). */ if (cached_lhs) { for (int i = 0; i < 2; i++) @@ -904,12 +904,10 @@ thread_through_normal_block (edge e, bitmap visited, bool *backedge_seen_p) { - /* If we have traversed a backedge, then we do not want to look - at certain expressions in the table that can not be relied upon. - Luckily the only code that looked at those expressions is the - SIMPLIFY callback, which we replace if we can no longer use it. */ + /* If we have seen a backedge, then we rely solely on the FSM threader + to find jump threads. */ if (*backedge_seen_p) - simplify = dummy_simplify; + return 0; /* We want to record any equivalences created by traversing E. */ if (!handle_dominating_asserts) @@ -1019,26 +1017,6 @@ thread_through_normal_block (edge e, backedge_seen_p); return 1; } - - if (!flag_expensive_optimizations - || optimize_function_for_size_p (cfun) - || !(TREE_CODE (cond) == SSA_NAME - || (TREE_CODE_CLASS (TREE_CODE (cond)) == tcc_comparison - && TREE_CODE (TREE_OPERAND (cond, 0)) == SSA_NAME - && TREE_CODE (TREE_OPERAND (cond, 1)) == INTEGER_CST)) - || e->dest->loop_father != e->src->loop_father - || loop_depth (e->dest->loop_father) == 0) - return 0; - - /* Extract the SSA_NAME we want to trace backwards if COND is not - already a bare SSA_NAME. */ - if (TREE_CODE (cond) != SSA_NAME) - cond = TREE_OPERAND (cond, 0); - - /* When COND cannot be simplified, try to find paths from a control - statement back through the PHI nodes which would affect that control - statement. */ - find_jump_threads_backwards (cond, e->dest); } return 0; } @@ -1118,6 +1096,8 @@ thread_across_edge (gcond *dummy_cond, path->release (); delete path; + find_jump_threads_backwards (e); + /* A negative status indicates the target block was deemed too big to duplicate. Just quit now rather than trying to use the block as a joiner in a jump threading path. @@ -1217,6 +1197,7 @@ thread_across_edge (gcond *dummy_cond, } else { + find_jump_threads_backwards (path->last ()->e); delete_jump_thread_path (path); } |