diff options
Diffstat (limited to 'gcc-4.2.1/gcc/cfglayout.c')
| -rw-r--r-- | gcc-4.2.1/gcc/cfglayout.c | 1283 |
1 files changed, 0 insertions, 1283 deletions
diff --git a/gcc-4.2.1/gcc/cfglayout.c b/gcc-4.2.1/gcc/cfglayout.c deleted file mode 100644 index cddb0daa5..000000000 --- a/gcc-4.2.1/gcc/cfglayout.c +++ /dev/null @@ -1,1283 +0,0 @@ -/* Basic block reordering routines for the GNU compiler. - Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. - -This file is part of GCC. - -GCC is free software; you can redistribute it and/or modify it under -the terms of the GNU General Public License as published by the Free -Software Foundation; either version 2, or (at your option) any later -version. - -GCC is distributed in the hope that it will be useful, but WITHOUT ANY -WARRANTY; without even the implied warranty of MERCHANTABILITY or -FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -for more details. - -You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING. If not, write to the Free -Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301, USA. */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "tree.h" -#include "rtl.h" -#include "hard-reg-set.h" -#include "obstack.h" -#include "basic-block.h" -#include "insn-config.h" -#include "output.h" -#include "function.h" -#include "cfglayout.h" -#include "cfgloop.h" -#include "target.h" -#include "ggc.h" -#include "alloc-pool.h" -#include "flags.h" -#include "tree-pass.h" -#include "vecprim.h" - -/* Holds the interesting trailing notes for the function. */ -rtx cfg_layout_function_footer, cfg_layout_function_header; - -static rtx skip_insns_after_block (basic_block); -static void record_effective_endpoints (void); -static rtx label_for_bb (basic_block); -static void fixup_reorder_chain (void); - -static void set_block_levels (tree, int); -static void change_scope (rtx, tree, tree); - -void verify_insn_chain (void); -static void fixup_fallthru_exit_predecessor (void); -static tree insn_scope (rtx); - -rtx -unlink_insn_chain (rtx first, rtx last) -{ - rtx prevfirst = PREV_INSN (first); - rtx nextlast = NEXT_INSN (last); - - PREV_INSN (first) = NULL; - NEXT_INSN (last) = NULL; - if (prevfirst) - NEXT_INSN (prevfirst) = nextlast; - if (nextlast) - PREV_INSN (nextlast) = prevfirst; - else - set_last_insn (prevfirst); - if (!prevfirst) - set_first_insn (nextlast); - return first; -} - -/* Skip over inter-block insns occurring after BB which are typically - associated with BB (e.g., barriers). If there are any such insns, - we return the last one. Otherwise, we return the end of BB. */ - -static rtx -skip_insns_after_block (basic_block bb) -{ - rtx insn, last_insn, next_head, prev; - - next_head = NULL_RTX; - if (bb->next_bb != EXIT_BLOCK_PTR) - next_head = BB_HEAD (bb->next_bb); - - for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; ) - { - if (insn == next_head) - break; - - switch (GET_CODE (insn)) - { - case BARRIER: - last_insn = insn; - continue; - - case NOTE: - switch (NOTE_LINE_NUMBER (insn)) - { - case NOTE_INSN_BLOCK_END: - last_insn = insn; - continue; - case NOTE_INSN_DELETED: - case NOTE_INSN_DELETED_LABEL: - continue; - - default: - continue; - break; - } - break; - - case CODE_LABEL: - if (NEXT_INSN (insn) - && JUMP_P (NEXT_INSN (insn)) - && (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC - || GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC)) - { - insn = NEXT_INSN (insn); - last_insn = insn; - continue; - } - break; - - default: - break; - } - - break; - } - - /* It is possible to hit contradictory sequence. For instance: - - jump_insn - NOTE_INSN_BLOCK_BEG - barrier - - Where barrier belongs to jump_insn, but the note does not. This can be - created by removing the basic block originally following - NOTE_INSN_BLOCK_BEG. In such case reorder the notes. */ - - for (insn = last_insn; insn != BB_END (bb); insn = prev) - { - prev = PREV_INSN (insn); - if (NOTE_P (insn)) - switch (NOTE_LINE_NUMBER (insn)) - { - case NOTE_INSN_BLOCK_END: - case NOTE_INSN_DELETED: - case NOTE_INSN_DELETED_LABEL: - continue; - default: - reorder_insns (insn, insn, last_insn); - } - } - - return last_insn; -} - -/* Locate or create a label for a given basic block. */ - -static rtx -label_for_bb (basic_block bb) -{ - rtx label = BB_HEAD (bb); - - if (!LABEL_P (label)) - { - if (dump_file) - fprintf (dump_file, "Emitting label for block %d\n", bb->index); - - label = block_label (bb); - } - - return label; -} - -/* Locate the effective beginning and end of the insn chain for each - block, as defined by skip_insns_after_block above. */ - -static void -record_effective_endpoints (void) -{ - rtx next_insn; - basic_block bb; - rtx insn; - - for (insn = get_insns (); - insn - && NOTE_P (insn) - && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; - insn = NEXT_INSN (insn)) - continue; - /* No basic blocks at all? */ - gcc_assert (insn); - - if (PREV_INSN (insn)) - cfg_layout_function_header = - unlink_insn_chain (get_insns (), PREV_INSN (insn)); - else - cfg_layout_function_header = NULL_RTX; - - next_insn = get_insns (); - FOR_EACH_BB (bb) - { - rtx end; - - if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb)) - bb->il.rtl->header = unlink_insn_chain (next_insn, - PREV_INSN (BB_HEAD (bb))); - end = skip_insns_after_block (bb); - if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end) - bb->il.rtl->footer = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end); - next_insn = NEXT_INSN (BB_END (bb)); - } - - cfg_layout_function_footer = next_insn; - if (cfg_layout_function_footer) - cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ()); -} - -/* Data structures representing mapping of INSN_LOCATOR into scope blocks, line - numbers and files. In order to be GGC friendly we need to use separate - varrays. This also slightly improve the memory locality in binary search. - The _locs array contains locators where the given property change. The - block_locators_blocks contains the scope block that is used for all insn - locator greater than corresponding block_locators_locs value and smaller - than the following one. Similarly for the other properties. */ -static VEC(int,heap) *block_locators_locs; -static GTY(()) VEC(tree,gc) *block_locators_blocks; -static VEC(int,heap) *line_locators_locs; -static VEC(int,heap) *line_locators_lines; -static VEC(int,heap) *file_locators_locs; -static GTY(()) varray_type file_locators_files; -int prologue_locator; -int epilogue_locator; - -/* During the RTL expansion the lexical blocks and line numbers are - represented via INSN_NOTEs. Replace them by representation using - INSN_LOCATORs. */ - -unsigned int -insn_locators_initialize (void) -{ - tree block = NULL; - tree last_block = NULL; - rtx insn, next; - int loc = 0; - int line_number = 0, last_line_number = 0; - const char *file_name = NULL, *last_file_name = NULL; - - prologue_locator = epilogue_locator = 0; - - block_locators_locs = VEC_alloc (int, heap, 32); - block_locators_blocks = VEC_alloc (tree, gc, 32); - line_locators_locs = VEC_alloc (int, heap, 32); - line_locators_lines = VEC_alloc (int, heap, 32); - file_locators_locs = VEC_alloc (int, heap, 32); - VARRAY_CHAR_PTR_INIT (file_locators_files, 32, "file_locators_files"); - - for (insn = get_insns (); insn; insn = next) - { - int active = 0; - - next = NEXT_INSN (insn); - - if (NOTE_P (insn)) - { - gcc_assert (NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_BEG - && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_END); - if (NOTE_LINE_NUMBER (insn) > 0) - { - expanded_location xloc; - NOTE_EXPANDED_LOCATION (xloc, insn); - line_number = xloc.line; - file_name = xloc.file; - } - } - else - active = (active_insn_p (insn) - && GET_CODE (PATTERN (insn)) != ADDR_VEC - && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC); - - check_block_change (insn, &block); - - if (active - || !next - || (!prologue_locator && file_name)) - { - if (last_block != block) - { - loc++; - VEC_safe_push (int, heap, block_locators_locs, loc); - VEC_safe_push (tree, gc, block_locators_blocks, block); - last_block = block; - } - if (last_line_number != line_number) - { - loc++; - VEC_safe_push (int, heap, line_locators_locs, loc); - VEC_safe_push (int, heap, line_locators_lines, line_number); - last_line_number = line_number; - } - if (last_file_name != file_name) - { - loc++; - VEC_safe_push (int, heap, file_locators_locs, loc); - VARRAY_PUSH_CHAR_PTR (file_locators_files, (char *) file_name); - last_file_name = file_name; - } - if (!prologue_locator && file_name) - prologue_locator = loc; - if (!next) - epilogue_locator = loc; - if (active) - INSN_LOCATOR (insn) = loc; - } - } - - /* Tag the blocks with a depth number so that change_scope can find - the common parent easily. */ - set_block_levels (DECL_INITIAL (cfun->decl), 0); - - free_block_changes (); - return 0; -} - -struct tree_opt_pass pass_insn_locators_initialize = -{ - "locators", /* name */ - NULL, /* gate */ - insn_locators_initialize, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - 0, /* tv_id */ - 0, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_dump_func, /* todo_flags_finish */ - 0 /* letter */ -}; - - -/* For each lexical block, set BLOCK_NUMBER to the depth at which it is - found in the block tree. */ - -static void -set_block_levels (tree block, int level) -{ - while (block) - { - BLOCK_NUMBER (block) = level; - set_block_levels (BLOCK_SUBBLOCKS (block), level + 1); - block = BLOCK_CHAIN (block); - } -} - -/* Return sope resulting from combination of S1 and S2. */ -static tree -choose_inner_scope (tree s1, tree s2) -{ - if (!s1) - return s2; - if (!s2) - return s1; - if (BLOCK_NUMBER (s1) > BLOCK_NUMBER (s2)) - return s1; - return s2; -} - -/* Emit lexical block notes needed to change scope from S1 to S2. */ - -static void -change_scope (rtx orig_insn, tree s1, tree s2) -{ - rtx insn = orig_insn; - tree com = NULL_TREE; - tree ts1 = s1, ts2 = s2; - tree s; - - while (ts1 != ts2) - { - gcc_assert (ts1 && ts2); - if (BLOCK_NUMBER (ts1) > BLOCK_NUMBER (ts2)) - ts1 = BLOCK_SUPERCONTEXT (ts1); - else if (BLOCK_NUMBER (ts1) < BLOCK_NUMBER (ts2)) - ts2 = BLOCK_SUPERCONTEXT (ts2); - else - { - ts1 = BLOCK_SUPERCONTEXT (ts1); - ts2 = BLOCK_SUPERCONTEXT (ts2); - } - } - com = ts1; - - /* Close scopes. */ - s = s1; - while (s != com) - { - rtx note = emit_note_before (NOTE_INSN_BLOCK_END, insn); - NOTE_BLOCK (note) = s; - s = BLOCK_SUPERCONTEXT (s); - } - - /* Open scopes. */ - s = s2; - while (s != com) - { - insn = emit_note_before (NOTE_INSN_BLOCK_BEG, insn); - NOTE_BLOCK (insn) = s; - s = BLOCK_SUPERCONTEXT (s); - } -} - -/* Return lexical scope block insn belong to. */ -static tree -insn_scope (rtx insn) -{ - int max = VEC_length (int, block_locators_locs); - int min = 0; - int loc = INSN_LOCATOR (insn); - - /* When block_locators_locs was initialized, the pro- and epilogue - insns didn't exist yet and can therefore not be found this way. - But we know that they belong to the outer most block of the - current function. - Without this test, the prologue would be put inside the block of - the first valid instruction in the function and when that first - insn is part of an inlined function then the low_pc of that - inlined function is messed up. Likewise for the epilogue and - the last valid instruction. */ - if (loc == prologue_locator || loc == epilogue_locator) - return DECL_INITIAL (cfun->decl); - - if (!max || !loc) - return NULL; - while (1) - { - int pos = (min + max) / 2; - int tmp = VEC_index (int, block_locators_locs, pos); - - if (tmp <= loc && min != pos) - min = pos; - else if (tmp > loc && max != pos) - max = pos; - else - { - min = pos; - break; - } - } - return VEC_index (tree, block_locators_blocks, min); -} - -/* Return line number of the statement specified by the locator. */ -int -locator_line (int loc) -{ - int max = VEC_length (int, line_locators_locs); - int min = 0; - - if (!max || !loc) - return 0; - while (1) - { - int pos = (min + max) / 2; - int tmp = VEC_index (int, line_locators_locs, pos); - - if (tmp <= loc && min != pos) - min = pos; - else if (tmp > loc && max != pos) - max = pos; - else - { - min = pos; - break; - } - } - return VEC_index (int, line_locators_lines, min); -} - -/* Return line number of the statement that produced this insn. */ -int -insn_line (rtx insn) -{ - return locator_line (INSN_LOCATOR (insn)); -} - -/* Return source file of the statement specified by LOC. */ -const char * -locator_file (int loc) -{ - int max = VEC_length (int, file_locators_locs); - int min = 0; - - if (!max || !loc) - return NULL; - while (1) - { - int pos = (min + max) / 2; - int tmp = VEC_index (int, file_locators_locs, pos); - - if (tmp <= loc && min != pos) - min = pos; - else if (tmp > loc && max != pos) - max = pos; - else - { - min = pos; - break; - } - } - return VARRAY_CHAR_PTR (file_locators_files, min); -} - -/* Return source file of the statement that produced this insn. */ -const char * -insn_file (rtx insn) -{ - return locator_file (INSN_LOCATOR (insn)); -} - -/* Rebuild all the NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes based - on the scope tree and the newly reordered instructions. */ - -void -reemit_insn_block_notes (void) -{ - tree cur_block = DECL_INITIAL (cfun->decl); - rtx insn, note; - - insn = get_insns (); - if (!active_insn_p (insn)) - insn = next_active_insn (insn); - for (; insn; insn = next_active_insn (insn)) - { - tree this_block; - - /* Avoid putting scope notes between jump table and its label. */ - if (JUMP_P (insn) - && (GET_CODE (PATTERN (insn)) == ADDR_VEC - || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) - continue; - - this_block = insn_scope (insn); - /* For sequences compute scope resulting from merging all scopes - of instructions nested inside. */ - if (GET_CODE (PATTERN (insn)) == SEQUENCE) - { - int i; - rtx body = PATTERN (insn); - - this_block = NULL; - for (i = 0; i < XVECLEN (body, 0); i++) - this_block = choose_inner_scope (this_block, - insn_scope (XVECEXP (body, 0, i))); - } - if (! this_block) - continue; - - if (this_block != cur_block) - { - change_scope (insn, cur_block, this_block); - cur_block = this_block; - } - } - - /* change_scope emits before the insn, not after. */ - note = emit_note (NOTE_INSN_DELETED); - change_scope (note, cur_block, DECL_INITIAL (cfun->decl)); - delete_insn (note); - - reorder_blocks (); -} - -/* Given a reorder chain, rearrange the code to match. */ - -static void -fixup_reorder_chain (void) -{ - basic_block bb, prev_bb; - int index; - rtx insn = NULL; - - if (cfg_layout_function_header) - { - set_first_insn (cfg_layout_function_header); - insn = cfg_layout_function_header; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - } - - /* 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++) - { - if (bb->il.rtl->header) - { - if (insn) - NEXT_INSN (insn) = bb->il.rtl->header; - else - set_first_insn (bb->il.rtl->header); - PREV_INSN (bb->il.rtl->header) = insn; - insn = bb->il.rtl->header; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - } - if (insn) - NEXT_INSN (insn) = BB_HEAD (bb); - else - set_first_insn (BB_HEAD (bb)); - PREV_INSN (BB_HEAD (bb)) = insn; - insn = BB_END (bb); - if (bb->il.rtl->footer) - { - NEXT_INSN (insn) = bb->il.rtl->footer; - PREV_INSN (bb->il.rtl->footer) = insn; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - } - } - - 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; - - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - - set_last_insn (insn); -#ifdef ENABLE_CHECKING - verify_insn_chain (); -#endif - delete_dead_jumptables (); - - /* Now add jumps and labels as needed to match the blocks new - outgoing edges. */ - - for (bb = ENTRY_BLOCK_PTR->next_bb; bb ; bb = bb->aux) - { - edge e_fall, e_taken, e; - rtx bb_end_insn; - basic_block nb; - edge_iterator ei; - - if (EDGE_COUNT (bb->succs) == 0) - continue; - - /* Find the old fallthru edge, and another non-EH edge for - a taken jump. */ - e_taken = e_fall = NULL; - - FOR_EACH_EDGE (e, ei, bb->succs) - if (e->flags & EDGE_FALLTHRU) - e_fall = e; - else if (! (e->flags & EDGE_EH)) - e_taken = e; - - bb_end_insn = BB_END (bb); - if (JUMP_P (bb_end_insn)) - { - if (any_condjump_p (bb_end_insn)) - { - /* If the old fallthru is still next, nothing to do. */ - if (bb->aux == e_fall->dest - || e_fall->dest == EXIT_BLOCK_PTR) - continue; - - /* The degenerated case of conditional jump jumping to the next - instruction can happen for jumps with side effects. We need - to construct a forwarder block and this will be done just - fine by force_nonfallthru below. */ - if (!e_taken) - ; - - /* There is another special case: if *neither* block is next, - such as happens at the very end of a function, then we'll - need to add a new unconditional jump. Choose the taken - edge based on known or assumed probability. */ - else if (bb->aux != e_taken->dest) - { - rtx note = find_reg_note (bb_end_insn, REG_BR_PROB, 0); - - if (note - && INTVAL (XEXP (note, 0)) < REG_BR_PROB_BASE / 2 - && invert_jump (bb_end_insn, - (e_fall->dest == EXIT_BLOCK_PTR - ? NULL_RTX - : label_for_bb (e_fall->dest)), 0)) - { - e_fall->flags &= ~EDGE_FALLTHRU; -#ifdef ENABLE_CHECKING - gcc_assert (could_fall_through - (e_taken->src, e_taken->dest)); -#endif - e_taken->flags |= EDGE_FALLTHRU; - update_br_prob_note (bb); - e = e_fall, e_fall = e_taken, e_taken = e; - } - } - - /* If the "jumping" edge is a crossing edge, and the fall - through edge is non-crossing, leave things as they are. */ - else if ((e_taken->flags & EDGE_CROSSING) - && !(e_fall->flags & EDGE_CROSSING)) - continue; - - /* Otherwise we can try to invert the jump. This will - basically never fail, however, keep up the pretense. */ - else if (invert_jump (bb_end_insn, - (e_fall->dest == EXIT_BLOCK_PTR - ? NULL_RTX - : label_for_bb (e_fall->dest)), 0)) - { - e_fall->flags &= ~EDGE_FALLTHRU; -#ifdef ENABLE_CHECKING - gcc_assert (could_fall_through - (e_taken->src, e_taken->dest)); -#endif - e_taken->flags |= EDGE_FALLTHRU; - update_br_prob_note (bb); - continue; - } - } - else - { - /* Otherwise we have some return, switch or computed - jump. In the 99% case, there should not have been a - fallthru edge. */ - gcc_assert (returnjump_p (bb_end_insn) || !e_fall); - continue; - } - } - else - { - /* No fallthru implies a noreturn function with EH edges, or - something similarly bizarre. In any case, we don't need to - do anything. */ - if (! e_fall) - continue; - - /* If the fallthru block is still next, nothing to do. */ - if (bb->aux == e_fall->dest) - continue; - - /* A fallthru to exit block. */ - if (e_fall->dest == EXIT_BLOCK_PTR) - continue; - } - - /* We got here if we need to add a new jump insn. */ - nb = force_nonfallthru (e_fall); - if (nb) - { - nb->il.rtl->visited = 1; - nb->aux = bb->aux; - bb->aux = nb; - /* Don't process this new block. */ - bb = nb; - - /* Make sure new bb is tagged for correct section (same as - fall-thru source, since you cannot fall-throu across - section boundaries). */ - BB_COPY_PARTITION (e_fall->src, single_pred (bb)); - if (flag_reorder_blocks_and_partition - && targetm.have_named_sections - && JUMP_P (BB_END (bb)) - && !any_condjump_p (BB_END (bb)) - && (EDGE_SUCC (bb, 0)->flags & EDGE_CROSSING)) - REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST - (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); - } - } - - /* 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; - - /* Annoying special case - jump around dead jumptables left in the code. */ - FOR_EACH_BB (bb) - { - edge e; - edge_iterator ei; - - FOR_EACH_EDGE (e, ei, bb->succs) - if (e->flags & EDGE_FALLTHRU) - break; - - if (e && !can_fallthru (e->src, e->dest)) - force_nonfallthru (e); - } -} - -/* Perform sanity checks on the insn chain. - 1. Check that next/prev pointers are consistent in both the forward and - reverse direction. - 2. Count insns in chain, going both directions, and check if equal. - 3. Check that get_last_insn () returns the actual end of chain. */ - -void -verify_insn_chain (void) -{ - rtx x, prevx, nextx; - int insn_cnt1, insn_cnt2; - - for (prevx = NULL, insn_cnt1 = 1, x = get_insns (); - x != 0; - prevx = x, insn_cnt1++, x = NEXT_INSN (x)) - gcc_assert (PREV_INSN (x) == prevx); - - gcc_assert (prevx == get_last_insn ()); - - for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn (); - x != 0; - nextx = x, insn_cnt2++, x = PREV_INSN (x)) - gcc_assert (NEXT_INSN (x) == nextx); - - gcc_assert (insn_cnt1 == insn_cnt2); -} - -/* If we have assembler epilogues, the block falling through to exit must - be the last one in the reordered chain when we reach final. Ensure - that this condition is met. */ -static void -fixup_fallthru_exit_predecessor (void) -{ - edge e; - edge_iterator ei; - basic_block bb = NULL; - - /* This transformation is not valid before reload, because we might - separate a call from the instruction that copies the return - value. */ - gcc_assert (reload_completed); - - FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) - if (e->flags & EDGE_FALLTHRU) - bb = e->src; - - if (bb && bb->aux) - { - basic_block c = ENTRY_BLOCK_PTR->next_bb; - - /* If the very first block is the one with the fall-through exit - edge, we have to split that block. */ - if (c == bb) - { - bb = split_block (bb, NULL)->dest; - bb->aux = c->aux; - c->aux = bb; - bb->il.rtl->footer = c->il.rtl->footer; - c->il.rtl->footer = NULL; - } - - while (c->aux != bb) - c = c->aux; - - c->aux = bb->aux; - while (c->aux) - c = c->aux; - - c->aux = bb; - bb->aux = NULL; - } -} - -/* Return true in case it is possible to duplicate the basic block BB. */ - -/* We do not want to declare the function in a header file, since it should - only be used through the cfghooks interface, and we do not want to move - it to cfgrtl.c since it would require also moving quite a lot of related - code. */ -extern bool cfg_layout_can_duplicate_bb_p (basic_block); - -bool -cfg_layout_can_duplicate_bb_p (basic_block bb) -{ - /* Do not attempt to duplicate tablejumps, as we need to unshare - the dispatch table. This is difficult to do, as the instructions - computing jump destination may be hoisted outside the basic block. */ - if (tablejump_p (BB_END (bb), NULL, NULL)) - return false; - - /* Do not duplicate blocks containing insns that can't be copied. */ - if (targetm.cannot_copy_insn_p) - { - rtx insn = BB_HEAD (bb); - while (1) - { - if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn)) - return false; - if (insn == BB_END (bb)) - break; - insn = NEXT_INSN (insn); - } - } - - return true; -} - -rtx -duplicate_insn_chain (rtx from, rtx to) -{ - rtx insn, last; - - /* Avoid updating of boundaries of previous basic block. The - note will get removed from insn stream in fixup. */ - last = emit_note (NOTE_INSN_DELETED); - - /* Create copy at the end of INSN chain. The chain will - be reordered later. */ - for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn)) - { - switch (GET_CODE (insn)) - { - case INSN: - case CALL_INSN: - case JUMP_INSN: - /* Avoid copying of dispatch tables. We never duplicate - tablejumps, so this can hit only in case the table got - moved far from original jump. */ - if (GET_CODE (PATTERN (insn)) == ADDR_VEC - || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) - break; - emit_copy_of_insn_after (insn, get_last_insn ()); - break; - - case CODE_LABEL: - break; - - case BARRIER: - emit_barrier (); - break; - - case NOTE: - switch (NOTE_LINE_NUMBER (insn)) - { - /* In case prologue is empty and function contain label - in first BB, we may want to copy the block. */ - case NOTE_INSN_PROLOGUE_END: - - case NOTE_INSN_DELETED: - case NOTE_INSN_DELETED_LABEL: - /* No problem to strip these. */ - case NOTE_INSN_EPILOGUE_BEG: - case NOTE_INSN_FUNCTION_END: - /* Debug code expect these notes to exist just once. - Keep them in the master copy. - ??? It probably makes more sense to duplicate them for each - epilogue copy. */ - case NOTE_INSN_FUNCTION_BEG: - /* There is always just single entry to function. */ - case NOTE_INSN_BASIC_BLOCK: - break; - - case NOTE_INSN_REPEATED_LINE_NUMBER: - case NOTE_INSN_SWITCH_TEXT_SECTIONS: - emit_note_copy (insn); - break; - - default: - /* All other notes should have already been eliminated. - */ - gcc_assert (NOTE_LINE_NUMBER (insn) >= 0); - - /* It is possible that no_line_number is set and the note - won't be emitted. */ - emit_note_copy (insn); - } - break; - default: - gcc_unreachable (); - } - } - insn = NEXT_INSN (last); - delete_insn (last); - return insn; -} -/* Create a duplicate of the basic block BB. */ - -/* We do not want to declare the function in a header file, since it should - only be used through the cfghooks interface, and we do not want to move - it to cfgrtl.c since it would require also moving quite a lot of related - code. */ -extern basic_block cfg_layout_duplicate_bb (basic_block); - -basic_block -cfg_layout_duplicate_bb (basic_block bb) -{ - rtx insn; - basic_block new_bb; - - insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb)); - new_bb = create_basic_block (insn, - insn ? get_last_insn () : NULL, - EXIT_BLOCK_PTR->prev_bb); - - BB_COPY_PARTITION (new_bb, bb); - if (bb->il.rtl->header) - { - insn = bb->il.rtl->header; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - insn = duplicate_insn_chain (bb->il.rtl->header, insn); - if (insn) - new_bb->il.rtl->header = unlink_insn_chain (insn, get_last_insn ()); - } - - if (bb->il.rtl->footer) - { - insn = bb->il.rtl->footer; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - insn = duplicate_insn_chain (bb->il.rtl->footer, insn); - if (insn) - new_bb->il.rtl->footer = unlink_insn_chain (insn, get_last_insn ()); - } - - if (bb->il.rtl->global_live_at_start) - { - new_bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); - new_bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); - COPY_REG_SET (new_bb->il.rtl->global_live_at_start, - bb->il.rtl->global_live_at_start); - COPY_REG_SET (new_bb->il.rtl->global_live_at_end, - bb->il.rtl->global_live_at_end); - } - - return new_bb; -} - -/* Main entry point to this module - initialize the datastructures for - CFG layout changes. It keeps LOOPS up-to-date if not null. - - FLAGS is a set of additional flags to pass to cleanup_cfg(). It should - include CLEANUP_UPDATE_LIFE if liveness information must be kept up - to date. */ - -void -cfg_layout_initialize (unsigned int flags) -{ - initialize_original_copy_tables (); - - cfg_layout_rtl_register_cfg_hooks (); - - record_effective_endpoints (); - - cleanup_cfg (CLEANUP_CFGLAYOUT | flags); -} - -/* Splits superblocks. */ -void -break_superblocks (void) -{ - sbitmap superblocks; - bool need = false; - basic_block bb; - - superblocks = sbitmap_alloc (last_basic_block); - sbitmap_zero (superblocks); - - FOR_EACH_BB (bb) - if (bb->flags & BB_SUPERBLOCK) - { - bb->flags &= ~BB_SUPERBLOCK; - SET_BIT (superblocks, bb->index); - need = true; - } - - if (need) - { - rebuild_jump_labels (get_insns ()); - find_many_sub_basic_blocks (superblocks); - } - - free (superblocks); -} - -/* Finalize the changes: reorder insn list according to the sequence specified - by aux pointers, enter compensation code, rebuild scope forest. */ - -void -cfg_layout_finalize (void) -{ - basic_block bb; - -#ifdef ENABLE_CHECKING - verify_flow_info (); -#endif - rtl_register_cfg_hooks (); - if (reload_completed -#ifdef HAVE_epilogue - && !HAVE_epilogue -#endif - ) - fixup_fallthru_exit_predecessor (); - fixup_reorder_chain (); - -#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; - } - - break_superblocks (); - -#ifdef ENABLE_CHECKING - verify_flow_info (); -#endif - - free_original_copy_tables (); -} - -/* Checks whether all N blocks in BBS array can be copied. */ -bool -can_copy_bbs_p (basic_block *bbs, unsigned n) -{ - unsigned i; - edge e; - int ret = true; - - for (i = 0; i < n; i++) - bbs[i]->flags |= BB_DUPLICATED; - - for (i = 0; i < n; i++) - { - /* In case we should redirect abnormal edge during duplication, fail. */ - edge_iterator ei; - FOR_EACH_EDGE (e, ei, bbs[i]->succs) - if ((e->flags & EDGE_ABNORMAL) - && (e->dest->flags & BB_DUPLICATED)) - { - ret = false; - goto end; - } - - if (!can_duplicate_block_p (bbs[i])) - { - ret = false; - break; - } - } - -end: - for (i = 0; i < n; i++) - bbs[i]->flags &= ~BB_DUPLICATED; - - return ret; -} - -/* Duplicates N basic blocks stored in array BBS. Newly created basic blocks - are placed into array NEW_BBS in the same order. Edges from basic blocks - in BBS are also duplicated and copies of those of them - that lead into BBS are redirected to appropriate newly created block. The - function assigns bbs into loops (copy of basic block bb is assigned to - bb->loop_father->copy loop, so this must be set up correctly in advance) - and updates dominators locally (LOOPS structure that contains the information - about dominators is passed to enable this). - - BASE is the superloop to that basic block belongs; if its header or latch - is copied, we do not set the new blocks as header or latch. - - Created copies of N_EDGES edges in array EDGES are stored in array NEW_EDGES, - also in the same order. - - Newly created basic blocks are put after the basic block AFTER in the - instruction stream, and the order of the blocks in BBS array is preserved. */ - -void -copy_bbs (basic_block *bbs, unsigned n, basic_block *new_bbs, - edge *edges, unsigned num_edges, edge *new_edges, - struct loop *base, basic_block after) -{ - unsigned i, j; - basic_block bb, new_bb, dom_bb; - edge e; - - /* Duplicate bbs, update dominators, assign bbs to loops. */ - for (i = 0; i < n; i++) - { - /* Duplicate. */ - bb = bbs[i]; - new_bb = new_bbs[i] = duplicate_block (bb, NULL, after); - after = new_bb; - bb->flags |= BB_DUPLICATED; - /* Add to loop. */ - add_bb_to_loop (new_bb, bb->loop_father->copy); - /* Possibly set header. */ - if (bb->loop_father->header == bb && bb->loop_father != base) - new_bb->loop_father->header = new_bb; - /* Or latch. */ - if (bb->loop_father->latch == bb && bb->loop_father != base) - new_bb->loop_father->latch = new_bb; - } - - /* Set dominators. */ - for (i = 0; i < n; i++) - { - bb = bbs[i]; - new_bb = new_bbs[i]; - - dom_bb = get_immediate_dominator (CDI_DOMINATORS, bb); - if (dom_bb->flags & BB_DUPLICATED) - { - dom_bb = get_bb_copy (dom_bb); - set_immediate_dominator (CDI_DOMINATORS, new_bb, dom_bb); - } - } - - /* Redirect edges. */ - for (j = 0; j < num_edges; j++) - new_edges[j] = NULL; - for (i = 0; i < n; i++) - { - edge_iterator ei; - new_bb = new_bbs[i]; - bb = bbs[i]; - - FOR_EACH_EDGE (e, ei, new_bb->succs) - { - for (j = 0; j < num_edges; j++) - if (edges[j] && edges[j]->src == bb && edges[j]->dest == e->dest) - new_edges[j] = e; - - if (!(e->dest->flags & BB_DUPLICATED)) - continue; - redirect_edge_and_branch_force (e, get_bb_copy (e->dest)); - } - } - - /* Clear information about duplicates. */ - for (i = 0; i < n; i++) - bbs[i]->flags &= ~BB_DUPLICATED; -} - -#include "gt-cfglayout.h" |