diff options
Diffstat (limited to 'gcc/cfglayout.c')
| -rw-r--r-- | gcc/cfglayout.c | 130 |
1 files changed, 74 insertions, 56 deletions
diff --git a/gcc/cfglayout.c b/gcc/cfglayout.c index ef085fcf6d4..01784319c19 100644 --- a/gcc/cfglayout.c +++ b/gcc/cfglayout.c @@ -634,13 +634,83 @@ reemit_insn_block_notes (void) reorder_blocks (); } + +/* Link the basic blocks in the correct order, compacting the basic + block queue while at it. This also clears the visited flag on + all basic blocks. If STAY_IN_CFGLAYOUT_MODE is false, this function + also clears the basic block header and footer fields. + + This function is usually called after a pass (e.g. tracer) finishes + some transformations while in cfglayout mode. The required sequence + of the basic blocks is in a linked list along the bb->aux field. + This functions re-links the basic block prev_bb and next_bb pointers + accordingly, and it compacts and renumbers the blocks. */ + +void +relink_block_chain (bool stay_in_cfglayout_mode) +{ + basic_block bb, prev_bb; + int index; + + /* Maybe dump the re-ordered sequence. */ + if (dump_file) + { + fprintf (dump_file, "Reordered sequence:\n"); + for (bb = ENTRY_BLOCK_PTR->next_bb, index = NUM_FIXED_BLOCKS; + bb; + bb = bb->aux, index++) + { + fprintf (dump_file, " %i ", index); + if (get_bb_original (bb)) + fprintf (dump_file, "duplicate of %i ", + get_bb_original (bb)->index); + else if (forwarder_block_p (bb) + && !LABEL_P (BB_HEAD (bb))) + fprintf (dump_file, "compensation "); + else + fprintf (dump_file, "bb %i ", bb->index); + fprintf (dump_file, " [%i]\n", bb->frequency); + } + } + + /* Now reorder the blocks. */ + prev_bb = ENTRY_BLOCK_PTR; + bb = ENTRY_BLOCK_PTR->next_bb; + for (; bb; prev_bb = bb, bb = bb->aux) + { + bb->prev_bb = prev_bb; + prev_bb->next_bb = bb; + } + prev_bb->next_bb = EXIT_BLOCK_PTR; + EXIT_BLOCK_PTR->prev_bb = prev_bb; + + /* Then, clean up the aux and visited fields. */ + FOR_ALL_BB (bb) + { + bb->aux = NULL; + bb->il.rtl->visited = 0; + if (!stay_in_cfglayout_mode) + bb->il.rtl->header = bb->il.rtl->footer = NULL; + } + + /* Maybe reset the original copy tables, they are not valid anymore + when we renumber the basic blocks in compact_blocks. If we are + are going out of cfglayout mode, don't re-allocate the tables. */ + free_original_copy_tables (); + if (stay_in_cfglayout_mode) + initialize_original_copy_tables (); + + /* Finally, put basic_block_info in the new order. */ + compact_blocks (); +} + + /* Given a reorder chain, rearrange the code to match. */ static void fixup_reorder_chain (void) { - basic_block bb, prev_bb; - int index; + basic_block bb; rtx insn = NULL; if (cfg_layout_function_header) @@ -654,9 +724,7 @@ fixup_reorder_chain (void) /* First do the bulk reordering -- rechain the blocks without regard to the needed changes to jumps and labels. */ - for (bb = ENTRY_BLOCK_PTR->next_bb, index = NUM_FIXED_BLOCKS; - bb != 0; - bb = bb->aux, index++) + for (bb = ENTRY_BLOCK_PTR->next_bb; bb; bb = bb->aux) { if (bb->il.rtl->header) { @@ -684,8 +752,6 @@ fixup_reorder_chain (void) } } - gcc_assert (index == n_basic_blocks); - NEXT_INSN (insn) = cfg_layout_function_footer; if (cfg_layout_function_footer) PREV_INSN (cfg_layout_function_footer) = insn; @@ -837,42 +903,7 @@ fixup_reorder_chain (void) } } - /* Put basic_block_info in the new order. */ - - if (dump_file) - { - fprintf (dump_file, "Reordered sequence:\n"); - for (bb = ENTRY_BLOCK_PTR->next_bb, index = NUM_FIXED_BLOCKS; - bb; - bb = bb->aux, index++) - { - fprintf (dump_file, " %i ", index); - if (get_bb_original (bb)) - fprintf (dump_file, "duplicate of %i ", - get_bb_original (bb)->index); - else if (forwarder_block_p (bb) - && !LABEL_P (BB_HEAD (bb))) - fprintf (dump_file, "compensation "); - else - fprintf (dump_file, "bb %i ", bb->index); - fprintf (dump_file, " [%i]\n", bb->frequency); - } - } - - prev_bb = ENTRY_BLOCK_PTR; - bb = ENTRY_BLOCK_PTR->next_bb; - index = NUM_FIXED_BLOCKS; - - for (; bb; prev_bb = bb, bb = bb->aux, index ++) - { - bb->index = index; - SET_BASIC_BLOCK (index, bb); - - bb->prev_bb = prev_bb; - prev_bb->next_bb = bb; - } - prev_bb->next_bb = EXIT_BLOCK_PTR; - EXIT_BLOCK_PTR->prev_bb = prev_bb; + relink_block_chain (/*stay_in_cfglayout_mode=*/false); /* Annoying special case - jump around dead jumptables left in the code. */ FOR_EACH_BB (bb) @@ -1178,8 +1209,6 @@ break_superblocks (void) void cfg_layout_finalize (void) { - basic_block bb; - #ifdef ENABLE_CHECKING verify_flow_info (); #endif @@ -1197,19 +1226,8 @@ cfg_layout_finalize (void) #ifdef ENABLE_CHECKING verify_insn_chain (); -#endif - FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) - { - bb->il.rtl->header = bb->il.rtl->footer = NULL; - bb->aux = NULL; - bb->il.rtl->visited = 0; - } - -#ifdef ENABLE_CHECKING verify_flow_info (); #endif - - free_original_copy_tables (); } /* Checks whether all N blocks in BBS array can be copied. */ |