diff options
Diffstat (limited to 'gcc/cfgcleanup.c')
| -rw-r--r-- | gcc/cfgcleanup.c | 67 |
1 files changed, 47 insertions, 20 deletions
diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c index 0ad1c6bcd33..da874f77268 100644 --- a/gcc/cfgcleanup.c +++ b/gcc/cfgcleanup.c @@ -77,7 +77,6 @@ static bool label_is_jump_target_p (rtx, rtx); static bool tail_recursion_label_p (rtx); static void merge_blocks_move_predecessor_nojumps (basic_block, basic_block); static void merge_blocks_move_successor_nojumps (basic_block, basic_block); -static basic_block merge_blocks (edge,basic_block,basic_block, int); static bool try_optimize_cfg (int); static bool try_simplify_condjump (basic_block); static bool try_forward_edges (int, basic_block); @@ -704,7 +703,7 @@ merge_blocks_move_predecessor_nojumps (basic_block a, basic_block b) link_block (a, b->prev_bb); /* Now blocks A and B are contiguous. Merge them. */ - merge_blocks_nomove (a, b); + merge_blocks (a, b); } /* Blocks A and B are to be merged into a single block. B has no outgoing @@ -758,7 +757,7 @@ merge_blocks_move_successor_nojumps (basic_block a, basic_block b) b->index, a->index); /* Now blocks A and B are contiguous. Merge them. */ - merge_blocks_nomove (a, b); + merge_blocks (a, b); } /* Attempt to merge basic blocks that are potentially non-adjacent. @@ -774,7 +773,7 @@ merge_blocks_move_successor_nojumps (basic_block a, basic_block b) relative ordering of these two. Hopefully it is not too common. */ static basic_block -merge_blocks (edge e, basic_block b, basic_block c, int mode) +merge_blocks_move (edge e, basic_block b, basic_block c, int mode) { basic_block next; /* If C has a tail recursion label, do not merge. There is no @@ -790,7 +789,7 @@ merge_blocks (edge e, basic_block b, basic_block c, int mode) if (e->flags & EDGE_FALLTHRU) { int b_index = b->index, c_index = c->index; - merge_blocks_nomove (b, c); + merge_blocks (b, c); update_forwarder_flag (b); if (rtl_dump_file) @@ -1686,7 +1685,8 @@ try_optimize_cfg (int mode) b->index); delete_block (b); - changed = true; + if (!(mode & CLEANUP_CFGLAYOUT)) + changed = true; b = c; } @@ -1712,15 +1712,24 @@ try_optimize_cfg (int mode) { rtx label = b->head; - b->head = NEXT_INSN (b->head); delete_insn_chain (label, label); + /* In the case label is undeletable, move it after the + BASIC_BLOCK note. */ + if (NOTE_LINE_NUMBER (b->head) == NOTE_INSN_DELETED_LABEL) + { + rtx bb_note = NEXT_INSN (b->head); + + reorder_insns_nobb (label, label, bb_note); + b->head = bb_note; + } if (rtl_dump_file) fprintf (rtl_dump_file, "Deleted label in block %i.\n", b->index); } /* If we fall through an empty block, we can remove it. */ - if (b->pred->pred_next == NULL + if (!(mode & CLEANUP_CFGLAYOUT) + && b->pred->pred_next == NULL && (b->pred->flags & EDGE_FALLTHRU) && GET_CODE (b->head) != CODE_LABEL && FORWARDER_BLOCK_P (b) @@ -1746,21 +1755,39 @@ try_optimize_cfg (int mode) && !(s->flags & EDGE_COMPLEX) && (c = s->dest) != EXIT_BLOCK_PTR && c->pred->pred_next == NULL - && b != c - /* If the jump insn has side effects, - we can't kill the edge. */ - && (GET_CODE (b->end) != JUMP_INSN - || (flow2_completed - ? simplejump_p (b->end) - : onlyjump_p (b->end))) - && (next = merge_blocks (s, b, c, mode))) - { - b = next; - changed_here = true; + && b != c) + { + /* When not in cfg_layout mode use code aware of reordering + INSN. This code possibly creates new basic blocks so it + does not fit merge_blocks interface and is kept here in + hope that it will become useless once more of compiler + is transformed to use cfg_layout mode. */ + + if ((mode & CLEANUP_CFGLAYOUT) + && can_merge_blocks_p (b, c)) + { + merge_blocks (b, c); + update_forwarder_flag (b); + changed_here = true; + } + else if (!(mode & CLEANUP_CFGLAYOUT) + /* If the jump insn has side effects, + we can't kill the edge. */ + && (GET_CODE (b->end) != JUMP_INSN + || (flow2_completed + ? simplejump_p (b->end) + : onlyjump_p (b->end))) + && (next = merge_blocks_move (s, b, c, mode))) + { + b = next; + changed_here = true; + } } /* Simplify branch over branch. */ - if ((mode & CLEANUP_EXPENSIVE) && try_simplify_condjump (b)) + if ((mode & CLEANUP_EXPENSIVE) + && !(mode & CLEANUP_CFGLAYOUT) + && try_simplify_condjump (b)) changed_here = true; /* If B has a single outgoing edge, but uses a |