diff options
Diffstat (limited to 'gcc/flow.c')
| -rw-r--r-- | gcc/flow.c | 417 |
1 files changed, 108 insertions, 309 deletions
@@ -204,7 +204,6 @@ struct basic_block_def entry_exit_blocks[2] NULL, /* aux */ ENTRY_BLOCK, /* index */ 0, /* loop_depth */ - -1, -1, /* eh_beg, eh_end */ 0 /* count */ }, { @@ -219,7 +218,6 @@ struct basic_block_def entry_exit_blocks[2] NULL, /* aux */ EXIT_BLOCK, /* index */ 0, /* loop_depth */ - -1, -1, /* eh_beg, eh_end */ 0 /* count */ } }; @@ -368,16 +366,12 @@ static void clear_edges PARAMS ((void)); static void make_edges PARAMS ((rtx)); static void make_label_edge PARAMS ((sbitmap *, basic_block, rtx, int)); -static void make_eh_edge PARAMS ((sbitmap *, eh_nesting_info *, - basic_block, rtx, int)); +static void make_eh_edge PARAMS ((sbitmap *, basic_block, rtx)); static void mark_critical_edges PARAMS ((void)); -static void move_stray_eh_region_notes PARAMS ((void)); -static void record_active_eh_regions PARAMS ((rtx)); static void commit_one_edge_insertion PARAMS ((edge)); static void delete_unreachable_blocks PARAMS ((void)); -static void delete_eh_regions PARAMS ((void)); static int can_delete_note_p PARAMS ((rtx)); static void expunge_block PARAMS ((basic_block)); static int can_delete_label_p PARAMS ((rtx)); @@ -537,7 +531,6 @@ find_basic_blocks (f, nregs, file) compute_bb_for_insn (max_uid); /* Discover the edges of our cfg. */ - record_active_eh_regions (f); make_edges (label_value_list); /* Do very simple cleanup now, for the benefit of code that runs between @@ -599,46 +592,45 @@ count_basic_blocks (f) register rtx insn; register RTX_CODE prev_code; register int count = 0; - int eh_region = 0; - int call_had_abnormal_edge = 0; + int saw_abnormal_edge = 0; prev_code = JUMP_INSN; for (insn = f; insn; insn = NEXT_INSN (insn)) { - register RTX_CODE code = GET_CODE (insn); + enum rtx_code code = GET_CODE (insn); if (code == CODE_LABEL || (GET_RTX_CLASS (code) == 'i' && (prev_code == JUMP_INSN || prev_code == BARRIER - || (prev_code == CALL_INSN && call_had_abnormal_edge)))) - count++; + || saw_abnormal_edge))) + { + saw_abnormal_edge = 0; + count++; + } - /* Record whether this call created an edge. */ + /* Record whether this insn created an edge. */ if (code == CALL_INSN) { - rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); - int region = (note ? INTVAL (XEXP (note, 0)) : 1); - - call_had_abnormal_edge = 0; - - /* If there is an EH region or rethrow, we have an edge. */ - if ((eh_region && region > 0) - || find_reg_note (insn, REG_EH_RETHROW, NULL_RTX)) - call_had_abnormal_edge = 1; - else if (nonlocal_goto_handler_labels && region >= 0) - /* If there is a nonlocal goto label and the specified - region number isn't -1, we have an edge. (0 means - no throw, but might have a nonlocal goto). */ - call_had_abnormal_edge = 1; + rtx note; + + /* If there is a nonlocal goto label and the specified + region number isn't -1, we have an edge. */ + if (nonlocal_goto_handler_labels + && ((note = find_reg_note (insn, REG_EH_REGION, NULL_RTX)) == 0 + || INTVAL (XEXP (note, 0)) >= 0)) + saw_abnormal_edge = 1; + + else if (can_throw_internal (insn)) + saw_abnormal_edge = 1; } + else if (flag_non_call_exceptions + && code == INSN + && can_throw_internal (insn)) + saw_abnormal_edge = 1; if (code != NOTE) prev_code = code; - else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) - ++eh_region; - else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) - --eh_region; } /* The rest of the compiler works a bit smoother when we don't have to @@ -672,9 +664,6 @@ find_label_refs (f, lvl) Make a special exception for labels followed by an ADDR*VEC, as this would be a part of the tablejump setup code. - Make a special exception for the eh_return_stub_label, which - we know isn't part of any otherwise visible control flow. - Make a special exception to registers loaded with label values just before jump insns that use them. */ @@ -683,9 +672,7 @@ find_label_refs (f, lvl) { rtx lab = XEXP (note, 0), next; - if (lab == eh_return_stub_label) - ; - else if ((next = next_nonnote_insn (lab)) != NULL + if ((next = next_nonnote_insn (lab)) != NULL && GET_CODE (next) == JUMP_INSN && (GET_CODE (PATTERN (next)) == ADDR_VEC || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) @@ -815,7 +802,6 @@ find_basic_blocks_1 (f) register rtx insn, next; int i = 0; rtx bb_note = NULL_RTX; - rtx eh_list = NULL_RTX; rtx lvl = NULL_RTX; rtx trll = NULL_RTX; rtx head = NULL_RTX; @@ -839,22 +825,11 @@ find_basic_blocks_1 (f) { int kind = NOTE_LINE_NUMBER (insn); - /* Keep a LIFO list of the currently active exception notes. */ - if (kind == NOTE_INSN_EH_REGION_BEG) - eh_list = alloc_INSN_LIST (insn, eh_list); - else if (kind == NOTE_INSN_EH_REGION_END) - { - rtx t = eh_list; - - eh_list = XEXP (eh_list, 1); - free_INSN_LIST_node (t); - } - /* Look for basic block notes with which to keep the basic_block_info pointers stable. Unthread the note now; we'll put it back at the right place in create_basic_block. Or not at all if we've already found a note in this block. */ - else if (kind == NOTE_INSN_BASIC_BLOCK) + if (kind == NOTE_INSN_BASIC_BLOCK) { if (bb_note == NULL_RTX) bb_note = insn; @@ -938,8 +913,7 @@ find_basic_blocks_1 (f) { /* Record whether this call created an edge. */ rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); - int region = (note ? INTVAL (XEXP (note, 0)) : 1); - int call_has_abnormal_edge = 0; + int region = (note ? INTVAL (XEXP (note, 0)) : 0); if (GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) { @@ -952,19 +926,10 @@ find_basic_blocks_1 (f) trll = alloc_EXPR_LIST (0, XEXP (PATTERN (insn), 3), trll); } - /* If there is an EH region or rethrow, we have an edge. */ - if ((eh_list && region > 0) - || find_reg_note (insn, REG_EH_RETHROW, NULL_RTX)) - call_has_abnormal_edge = 1; - else if (nonlocal_goto_handler_labels && region >= 0) - /* If there is a nonlocal goto label and the specified - region number isn't -1, we have an edge. (0 means - no throw, but might have a nonlocal goto). */ - call_has_abnormal_edge = 1; - /* A basic block ends at a call that can either throw or do a non-local goto. */ - if (call_has_abnormal_edge) + if ((nonlocal_goto_handler_labels && region >= 0) + || can_throw_internal (insn)) { new_bb_inclusive: if (head == NULL_RTX) @@ -980,18 +945,21 @@ find_basic_blocks_1 (f) } /* Fall through. */ - default: - if (GET_RTX_CLASS (code) == 'i') - { - if (head == NULL_RTX) - head = insn; - end = insn; - } + case INSN: + /* Non-call exceptions generate new blocks just like calls. */ + if (flag_non_call_exceptions && can_throw_internal (insn)) + goto new_bb_inclusive; + + if (head == NULL_RTX) + head = insn; + end = insn; break; + + default: + abort (); } - if (GET_RTX_CLASS (code) == 'i' - && GET_CODE (insn) != JUMP_INSN) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN) { rtx note; @@ -1000,9 +968,6 @@ find_basic_blocks_1 (f) Make a special exception for labels followed by an ADDR*VEC, as this would be a part of the tablejump setup code. - Make a special exception for the eh_return_stub_label, which - we know isn't part of any otherwise visible control flow. - Make a special exception to registers loaded with label values just before jump insns that use them. */ @@ -1011,9 +976,7 @@ find_basic_blocks_1 (f) { rtx lab = XEXP (note, 0), next; - if (lab == eh_return_stub_label) - ; - else if ((next = next_nonnote_insn (lab)) != NULL + if ((next = next_nonnote_insn (lab)) != NULL && GET_CODE (next) == JUMP_INSN && (GET_CODE (PATTERN (next)) == ADDR_VEC || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) @@ -1047,8 +1010,6 @@ void cleanup_cfg () { delete_unreachable_blocks (); - move_stray_eh_region_notes (); - record_active_eh_regions (get_insns ()); try_merge_blocks (); mark_critical_edges (); @@ -1201,7 +1162,6 @@ make_edges (label_value_list) rtx label_value_list; { int i; - eh_nesting_info *eh_nest_info = init_eh_nesting_info (); sbitmap *edge_cache = NULL; /* Assume no computed jump; revise as we create edges. */ @@ -1241,9 +1201,13 @@ make_edges (label_value_list) { rtx tmp; + /* Recognize exception handling placeholders. */ + if (GET_CODE (PATTERN (insn)) == RESX) + make_eh_edge (edge_cache, bb, insn); + /* Recognize a non-local goto as a branch outside the current function. */ - if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX)) + else if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX)) ; /* ??? Recognize a tablejump and do the right thing. */ @@ -1318,37 +1282,15 @@ make_edges (label_value_list) EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); /* If this is a CALL_INSN, then mark it as reaching the active EH - handler for this CALL_INSN. If we're handling asynchronous + handler for this CALL_INSN. If we're handling non-call exceptions then any insn can reach any of the active handlers. Also mark the CALL_INSN as reaching any nonlocal goto handler. */ else if (code == CALL_INSN || flag_non_call_exceptions) { - /* Add any appropriate EH edges. We do this unconditionally - since there may be a REG_EH_REGION or REG_EH_RETHROW note - on the call, and this needn't be within an EH region. */ - make_eh_edge (edge_cache, eh_nest_info, bb, insn, bb->eh_end); - - /* If we have asynchronous exceptions, do the same for *all* - exception regions active in the block. */ - if (flag_non_call_exceptions - && bb->eh_beg != bb->eh_end) - { - if (bb->eh_beg >= 0) - make_eh_edge (edge_cache, eh_nest_info, bb, - NULL_RTX, bb->eh_beg); - - for (x = bb->head; x != bb->end; x = NEXT_INSN (x)) - if (GET_CODE (x) == NOTE - && (NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_BEG - || NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_END)) - { - int region = NOTE_EH_HANDLER (x); - make_eh_edge (edge_cache, eh_nest_info, bb, - NULL_RTX, region); - } - } + /* Add any appropriate EH edges. */ + make_eh_edge (edge_cache, bb, insn); if (code == CALL_INSN && nonlocal_goto_handler_labels) { @@ -1369,14 +1311,6 @@ make_edges (label_value_list) } } - /* We know something about the structure of the function __throw in - libgcc2.c. It is the only function that ever contains eh_stub - labels. It modifies its return address so that the last block - returns to one of the eh_stub labels within it. So we have to - make additional edges in the flow graph. */ - if (i + 1 == n_basic_blocks && eh_return_stub_label != 0) - make_label_edge (edge_cache, bb, eh_return_stub_label, EDGE_EH); - /* Find out if we can drop through to the next block. */ insn = next_nonnote_insn (insn); if (!insn || (i + 1 == n_basic_blocks && force_fallthru)) @@ -1391,7 +1325,6 @@ make_edges (label_value_list) } } - free_eh_nesting_info (eh_nest_info); if (edge_cache) sbitmap_vector_free (edge_cache); } @@ -1479,115 +1412,21 @@ make_label_edge (edge_cache, src, label, flags) /* Create the edges generated by INSN in REGION. */ static void -make_eh_edge (edge_cache, eh_nest_info, src, insn, region) +make_eh_edge (edge_cache, src, insn) sbitmap *edge_cache; - eh_nesting_info *eh_nest_info; basic_block src; rtx insn; - int region; -{ - handler_info **handler_list; - int num, is_call; - - is_call = (insn && GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); - num = reachable_handlers (region, eh_nest_info, insn, &handler_list); - while (--num >= 0) - { - make_label_edge (edge_cache, src, handler_list[num]->handler_label, - EDGE_ABNORMAL | EDGE_EH | is_call); - } -} - -/* EH_REGION notes appearing between basic blocks is ambiguous, and even - dangerous if we intend to move basic blocks around. Move such notes - into the following block. */ - -static void -move_stray_eh_region_notes () -{ - int i; - basic_block b1, b2; - - if (n_basic_blocks < 2) - return; - - b2 = BASIC_BLOCK (n_basic_blocks - 1); - for (i = n_basic_blocks - 2; i >= 0; --i, b2 = b1) - { - rtx insn, next, list = NULL_RTX; - - b1 = BASIC_BLOCK (i); - for (insn = NEXT_INSN (b1->end); insn != b2->head; insn = next) - { - next = NEXT_INSN (insn); - if (GET_CODE (insn) == NOTE - && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG - || NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) - { - /* Unlink from the insn chain. */ - NEXT_INSN (PREV_INSN (insn)) = next; - PREV_INSN (next) = PREV_INSN (insn); - - /* Queue it. */ - NEXT_INSN (insn) = list; - list = insn; - } - } - - if (list == NULL_RTX) - continue; - - /* Find where to insert these things. */ - insn = b2->head; - if (GET_CODE (insn) == CODE_LABEL) - insn = NEXT_INSN (insn); - - while (list) - { - next = NEXT_INSN (list); - add_insn_after (list, insn); - list = next; - } - } -} - -/* Recompute eh_beg/eh_end for each basic block. */ - -static void -record_active_eh_regions (f) - rtx f; { - rtx insn, eh_list = NULL_RTX; - int i = 0; - basic_block bb = BASIC_BLOCK (0); + int is_call = (GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); + rtx handlers, i; - for (insn = f; insn; insn = NEXT_INSN (insn)) - { - if (bb->head == insn) - bb->eh_beg = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); + handlers = reachable_handlers (insn); - if (GET_CODE (insn) == NOTE) - { - int kind = NOTE_LINE_NUMBER (insn); - if (kind == NOTE_INSN_EH_REGION_BEG) - eh_list = alloc_INSN_LIST (insn, eh_list); - else if (kind == NOTE_INSN_EH_REGION_END) - { - rtx t = XEXP (eh_list, 1); - free_INSN_LIST_node (eh_list); - eh_list = t; - } - } + for (i = handlers; i; i = XEXP (i, 1)) + make_label_edge (edge_cache, src, XEXP (i, 0), + EDGE_ABNORMAL | EDGE_EH | is_call); - if (bb->end == insn) - { - bb->eh_end = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); - i += 1; - if (i == n_basic_blocks) - break; - bb = BASIC_BLOCK (i); - } - } + free_INSN_LIST_list (&handlers); } /* Identify critical edges and set the bits appropriately. */ @@ -2223,7 +2062,6 @@ static void delete_unreachable_blocks () { basic_block *worklist, *tos; - int deleted_handler; edge e; int i, n; @@ -2261,10 +2099,9 @@ delete_unreachable_blocks () } } - /* Delete all unreachable basic blocks. Count down so that we don't - interfere with the block renumbering that happens in flow_delete_block. */ - - deleted_handler = 0; + /* Delete all unreachable basic blocks. Count down so that we + don't interfere with the block renumbering that happens in + flow_delete_block. */ for (i = n - 1; i >= 0; --i) { @@ -2274,46 +2111,14 @@ delete_unreachable_blocks () /* This block was found. Tidy up the mark. */ b->aux = NULL; else - deleted_handler |= flow_delete_block (b); + flow_delete_block (b); } tidy_fallthru_edges (); - /* If we deleted an exception handler, we may have EH region begin/end - blocks to remove as well. */ - if (deleted_handler) - delete_eh_regions (); - free (worklist); } -/* Find EH regions for which there is no longer a handler, and delete them. */ - -static void -delete_eh_regions () -{ - rtx insn; - - update_rethrow_references (); - - for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) - if (GET_CODE (insn) == NOTE) - { - if ((NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) - || (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) - { - int num = NOTE_EH_HANDLER (insn); - /* A NULL handler indicates a region is no longer needed, - as long as its rethrow label isn't used. */ - if (get_first_handler (num) == NULL && ! rethrow_used (num)) - { - NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (insn) = 0; - } - } - } -} - /* Return true if NOTE is not one of the ones that must be kept paired, so that we may simply delete them. */ @@ -2387,26 +2192,7 @@ flow_delete_block (b) never_reached_warning (insn); if (GET_CODE (insn) == CODE_LABEL) - { - rtx x, *prev = &exception_handler_labels; - - for (x = exception_handler_labels; x; x = XEXP (x, 1)) - { - if (XEXP (x, 0) == insn) - { - /* Found a match, splice this label out of the EH label list. */ - *prev = XEXP (x, 1); - XEXP (x, 1) = NULL_RTX; - XEXP (x, 0) = NULL_RTX; - - /* Remove the handler from all regions */ - remove_handler (insn); - deleted_handler = 1; - break; - } - prev = &XEXP (x, 1); - } - } + maybe_remove_eh_handler (insn); /* Include any jump table following the basic block. */ end = b->end; @@ -2804,7 +2590,6 @@ merge_blocks (e, b, c) else { edge tmp_edge; - basic_block d; int c_has_outgoing_fallthru; int b_has_incoming_fallthru; @@ -2832,37 +2617,22 @@ merge_blocks (e, b, c) break; b_has_incoming_fallthru = (tmp_edge != NULL); - /* If B does not have an incoming fallthru, and the exception regions - match, then it can be moved immediately before C without introducing - or modifying jumps. - - C can not be the first block, so we do not have to worry about + /* If B does not have an incoming fallthru, then it can be moved + immediately before C without introducing or modifying jumps. + C cannot be the first block, so we do not have to worry about accessing a non-existent block. */ - d = BASIC_BLOCK (c->index - 1); - if (! b_has_incoming_fallthru - && d->eh_end == b->eh_beg - && b->eh_end == c->eh_beg) + if (! b_has_incoming_fallthru) return merge_blocks_move_predecessor_nojumps (b, c); - /* Otherwise, we're going to try to move C after B. Make sure the - exception regions match. + /* Otherwise, we're going to try to move C after B. If C does + not have an outgoing fallthru, then it can be moved + immediately after B without introducing or modifying jumps. */ + if (! c_has_outgoing_fallthru) + return merge_blocks_move_successor_nojumps (b, c); - If B is the last basic block, then we must not try to access the - block structure for block B + 1. Luckily in that case we do not - need to worry about matching exception regions. */ - d = (b->index + 1 < n_basic_blocks ? BASIC_BLOCK (b->index + 1) : NULL); - if (b->eh_end == c->eh_beg - && (d == NULL || c->eh_end == d->eh_beg)) - { - /* If C does not have an outgoing fallthru, then it can be moved - immediately after B without introducing or modifying jumps. */ - if (! c_has_outgoing_fallthru) - return merge_blocks_move_successor_nojumps (b, c); - - /* Otherwise, we'll need to insert an extra jump, and possibly - a new block to contain it. */ - /* ??? Not implemented yet. */ - } + /* Otherwise, we'll need to insert an extra jump, and possibly + a new block to contain it. */ + /* ??? Not implemented yet. */ return 0; } @@ -3502,14 +3272,44 @@ mark_regs_live_at_end (set) if (global_regs[i] || EPILOGUE_USES (i)) SET_REGNO_REG_SET (set, i); - /* Mark all call-saved registers that we actaully used. */ if (HAVE_epilogue && reload_completed) { + /* Mark all call-saved registers that we actually used. */ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) if (regs_ever_live[i] && ! call_used_regs[i] && ! LOCAL_REGNO (i)) SET_REGNO_REG_SET (set, i); } +#ifdef EH_RETURN_DATA_REGNO + /* Mark the registers that will contain data for the handler. */ + if (reload_completed && current_function_calls_eh_return) + for (i = 0; ; ++i) + { + unsigned regno = EH_RETURN_DATA_REGNO(i); + if (regno == INVALID_REGNUM) + break; + SET_REGNO_REG_SET (set, regno); + } +#endif +#ifdef EH_RETURN_STACKADJ_RTX + if ((! HAVE_epilogue || ! reload_completed) + && current_function_calls_eh_return) + { + rtx tmp = EH_RETURN_STACKADJ_RTX; + if (tmp && REG_P (tmp)) + mark_reg (tmp, set); + } +#endif +#ifdef EH_RETURN_HANDLER_RTX + if ((! HAVE_epilogue || ! reload_completed) + && current_function_calls_eh_return) + { + rtx tmp = EH_RETURN_HANDLER_RTX; + if (tmp && REG_P (tmp)) + mark_reg (tmp, set); + } +#endif + /* Mark function return value. */ diddle_return_value (mark_reg, set); } @@ -4249,7 +4049,8 @@ init_propagate_block_info (bb, live, local_set, cond_local_set, flags) && (flags & PROP_SCAN_DEAD_CODE) && (bb->succ == NULL || (bb->succ->succ_next == NULL - && bb->succ->dest == EXIT_BLOCK_PTR))) + && bb->succ->dest == EXIT_BLOCK_PTR + && ! current_function_calls_eh_return))) { rtx insn, set; for (insn = bb->end; insn != bb->head; insn = PREV_INSN (insn)) @@ -6631,8 +6432,6 @@ dump_bb (bb, outf) fprintf (outf, ";; Basic block %d, loop depth %d, count %d", bb->index, bb->loop_depth, bb->count); - if (bb->eh_beg != -1 || bb->eh_end != -1) - fprintf (outf, ", eh regions %d/%d", bb->eh_beg, bb->eh_end); putc ('\n', outf); fputs (";; Predecessors: ", outf); |