diff options
Diffstat (limited to 'gcc/tree-if-conv.c')
| -rw-r--r-- | gcc/tree-if-conv.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c index 46b20c2..ca8f84a 100644 --- a/gcc/tree-if-conv.c +++ b/gcc/tree-if-conv.c @@ -716,6 +716,20 @@ if_convertible_stmt_p (gimple stmt, VEC (data_reference_p, heap) *refs) return true; } +/* Return true when BB post-dominates all its predecessors. */ + +static bool +bb_postdominates_preds (basic_block bb) +{ + unsigned i; + + for (i = 0; i < EDGE_COUNT (bb->preds); i++) + if (!dominated_by_p (CDI_POST_DOMINATORS, EDGE_PRED (bb, i)->src, bb)) + return false; + + return true; +} + /* Return true when BB is if-convertible. This routine does not check basic block's statements and phis. @@ -774,6 +788,11 @@ if_convertible_bb_p (struct loop *loop, basic_block bb, basic_block exit_bb) return false; } + if (EDGE_COUNT (bb->preds) == 2 + && bb != loop->header + && !bb_postdominates_preds (bb)) + return false; + return true; } @@ -992,6 +1011,7 @@ if_convertible_loop_p_1 (struct loop *loop, return false; calculate_dominance_info (CDI_DOMINATORS); + calculate_dominance_info (CDI_POST_DOMINATORS); /* Allow statements that can be handled during if-conversion. */ ifc_bbs = get_loop_body_in_if_conv_order (loop); @@ -1262,6 +1282,9 @@ predicate_scalar_phi (gimple phi, tree cond, arg_1 = gimple_phi_arg_def (phi, 1); } + gcc_checking_assert (bb == bb->loop_father->header + || bb_postdominates_preds (bb)); + /* Build new RHS using selected condition and arguments. */ rhs = build3 (COND_EXPR, TREE_TYPE (res), unshare_expr (cond), arg_0, arg_1); |