diff options
Diffstat (limited to 'gcc/cfgexpand.c')
| -rw-r--r-- | gcc/cfgexpand.c | 98 |
1 files changed, 82 insertions, 16 deletions
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index ab2b9d36af2..643ff207108 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -1244,6 +1244,38 @@ maybe_dump_rtl_for_tree_stmt (tree stmt, rtx since) } } +/* Returns the label_rtx expression for a label starting basic block BB. */ + +static rtx +label_rtx_for_bb (basic_block bb) +{ + tree_stmt_iterator tsi; + tree lab, lab_stmt; + + if (bb->flags & BB_RTL) + return block_label (bb); + + /* We cannot use tree_block_label, as we no longer have stmt annotations. + TODO -- avoid creating the new tree labels. */ + for (tsi = tsi_start (bb_stmt_list (bb)); !tsi_end_p (tsi); tsi_next (&tsi)) + { + lab_stmt = tsi_stmt (tsi); + if (TREE_CODE (lab_stmt) != LABEL_EXPR) + break; + + lab = LABEL_EXPR_LABEL (lab_stmt); + if (DECL_NONLOCAL (lab)) + break; + + return label_rtx (lab); + } + + lab = create_artificial_label (); + lab_stmt = build1 (LABEL_EXPR, void_type_node, lab); + tsi_link_before (&tsi, lab_stmt, TSI_NEW_STMT); + return label_rtx (lab); +} + /* A subroutine of expand_gimple_basic_block. Expand one COND_EXPR. Returns a new basic block if we've terminated the current basic block and created a new one. */ @@ -1256,10 +1288,10 @@ expand_gimple_cond_expr (basic_block bb, tree stmt) edge true_edge; edge false_edge; tree pred = COND_EXPR_COND (stmt); - tree then_exp = COND_EXPR_THEN (stmt); - tree else_exp = COND_EXPR_ELSE (stmt); rtx last2, last; + gcc_assert (COND_EXPR_THEN (stmt) == NULL_TREE); + gcc_assert (COND_EXPR_ELSE (stmt) == NULL_TREE); last2 = last = get_last_insn (); extract_true_false_edges_from_block (bb, &true_edge, &false_edge); @@ -1275,31 +1307,31 @@ expand_gimple_cond_expr (basic_block bb, tree stmt) /* We can either have a pure conditional jump with one fallthru edge or two-way jump that needs to be decomposed into two basic blocks. */ - if (TREE_CODE (then_exp) == GOTO_EXPR && IS_EMPTY_STMT (else_exp)) + if (false_edge->dest == bb->next_bb) { - jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp))); + jumpif (pred, label_rtx_for_bb (true_edge->dest)); add_reg_br_prob_note (last, true_edge->probability); maybe_dump_rtl_for_tree_stmt (stmt, last); - if (EXPR_LOCUS (then_exp)) - emit_line_note (*(EXPR_LOCUS (then_exp))); + if (true_edge->goto_locus) + emit_line_note (*true_edge->goto_locus); + false_edge->flags |= EDGE_FALLTHRU; return NULL; } - if (TREE_CODE (else_exp) == GOTO_EXPR && IS_EMPTY_STMT (then_exp)) + if (true_edge->dest == bb->next_bb) { - jumpifnot (pred, label_rtx (GOTO_DESTINATION (else_exp))); + jumpifnot (pred, label_rtx_for_bb (false_edge->dest)); add_reg_br_prob_note (last, false_edge->probability); maybe_dump_rtl_for_tree_stmt (stmt, last); - if (EXPR_LOCUS (else_exp)) - emit_line_note (*(EXPR_LOCUS (else_exp))); + if (false_edge->goto_locus) + emit_line_note (*false_edge->goto_locus); + true_edge->flags |= EDGE_FALLTHRU; return NULL; } - gcc_assert (TREE_CODE (then_exp) == GOTO_EXPR - && TREE_CODE (else_exp) == GOTO_EXPR); - jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp))); + jumpif (pred, label_rtx_for_bb (true_edge->dest)); add_reg_br_prob_note (last, true_edge->probability); last = get_last_insn (); - expand_expr (else_exp, const0_rtx, VOIDmode, 0); + emit_jump (label_rtx_for_bb (false_edge->dest)); BB_END (bb) = last; if (BARRIER_P (BB_END (bb))) @@ -1321,8 +1353,8 @@ expand_gimple_cond_expr (basic_block bb, tree stmt) maybe_dump_rtl_for_tree_stmt (stmt, last2); - if (EXPR_LOCUS (else_exp)) - emit_line_note (*(EXPR_LOCUS (else_exp))); + if (false_edge->goto_locus) + emit_line_note (*false_edge->goto_locus); return new_bb; } @@ -1457,6 +1489,25 @@ expand_gimple_basic_block (basic_block bb) init_rtl_bb_info (bb); bb->flags |= BB_RTL; + /* Remove the RETURN_EXPR if we may fall though to the exit + instead. */ + tsi = tsi_last (stmts); + if (!tsi_end_p (tsi) + && TREE_CODE (tsi_stmt (tsi)) == RETURN_EXPR) + { + tree ret_stmt = tsi_stmt (tsi); + + gcc_assert (single_succ_p (bb)); + gcc_assert (single_succ (bb) == EXIT_BLOCK_PTR); + + if (bb->next_bb == EXIT_BLOCK_PTR + && !TREE_OPERAND (ret_stmt, 0)) + { + tsi_delink (&tsi); + single_succ_edge (bb)->flags |= EDGE_FALLTHRU; + } + } + tsi = tsi_start (stmts); if (!tsi_end_p (tsi)) stmt = tsi_stmt (tsi); @@ -1546,6 +1597,21 @@ expand_gimple_basic_block (basic_block bb) } } + /* Expand implicit goto. */ + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (e->flags & EDGE_FALLTHRU) + break; + } + + if (e && e->dest != bb->next_bb) + { + emit_jump (label_rtx_for_bb (e->dest)); + if (e->goto_locus) + emit_line_note (*e->goto_locus); + e->flags &= ~EDGE_FALLTHRU; + } + do_pending_stack_adjust (); /* Find the block tail. The last insn in the block is the insn |