diff options
Diffstat (limited to 'gcc/cfgrtl.c')
| -rw-r--r-- | gcc/cfgrtl.c | 208 |
1 files changed, 81 insertions, 127 deletions
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c index 70d06563ac6..01a5f3dbe66 100644 --- a/gcc/cfgrtl.c +++ b/gcc/cfgrtl.c @@ -76,18 +76,20 @@ static rtx last_loop_beg_note (rtx); static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); basic_block force_nonfallthru_and_redirect (edge, basic_block); static basic_block rtl_split_edge (edge); +static bool rtl_move_block_after (basic_block, basic_block); static int rtl_verify_flow_info (void); -static edge cfg_layout_split_block (basic_block, void *); +static basic_block cfg_layout_split_block (basic_block, void *); static bool cfg_layout_redirect_edge_and_branch (edge, basic_block); static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); static void cfg_layout_delete_block (basic_block); static void rtl_delete_block (basic_block); static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); static bool rtl_redirect_edge_and_branch (edge, basic_block); -static edge rtl_split_block (basic_block, void *); -static void rtl_dump_bb (basic_block, FILE *); +static basic_block rtl_split_block (basic_block, void *); +static void rtl_dump_bb (basic_block, FILE *, int); static int rtl_verify_flow_info_1 (void); static void mark_killed_regs (rtx, rtx, void *); +static void rtl_make_forwarder_block (edge); /* Return true if NOTE is not one of the ones that must be kept paired, so that we may simply delete it. */ @@ -337,7 +339,7 @@ rtl_create_basic_block (void *headp, void *endp, basic_block after) basic_block bb; /* Place the new block just after the end. */ - VARRAY_GROW (basic_block_info, last_basic_block+1); + VARRAY_GROW (basic_block_info, last_basic_block + 1); n_basic_blocks++; @@ -407,19 +409,6 @@ rtl_delete_block (basic_block b) /* Selectively delete the entire chain. */ BB_HEAD (b) = NULL; delete_insn_chain (insn, end); - - /* Remove the edges into and out of this block. Note that there may - indeed be edges in, if we are removing an unreachable loop. */ - while (b->pred != NULL) - remove_edge (b->pred); - while (b->succ != NULL) - remove_edge (b->succ); - - b->pred = NULL; - b->succ = NULL; - - /* Remove the basic block from the array. */ - expunge_block (b); } /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ @@ -470,28 +459,34 @@ update_bb_for_insn (basic_block bb) } } -/* Split a block BB after insn INSN creating a new fallthru edge. - Return the new edge. Note that to keep other parts of the compiler happy, - this function renumbers all the basic blocks so that the new - one has a number one greater than the block split. */ +/* Creates a new basic block just after basic block B by splitting + everything after specified instruction I. */ -static edge +static basic_block rtl_split_block (basic_block bb, void *insnp) { basic_block new_bb; - edge new_edge; - edge e; rtx insn = insnp; + edge e; - /* There is no point splitting the block after its end. */ - if (BB_END (bb) == insn) - return 0; + if (!insn) + { + insn = first_insn_after_basic_block_note (bb); + + if (insn) + insn = PREV_INSN (insn); + else + insn = get_last_insn (); + } + + /* We probably should check type of the insn so that we do not create + inconsistent cfg. It is checked in verify_flow_info anyway, so do not + bother. */ + if (insn == BB_END (bb)) + emit_note_after (NOTE_INSN_DELETED, insn); /* Create the new basic block. */ new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); - new_bb->count = bb->count; - new_bb->frequency = bb->frequency; - new_bb->loop_depth = bb->loop_depth; BB_END (bb) = insn; /* Redirect the outgoing edges. */ @@ -500,8 +495,6 @@ rtl_split_block (basic_block bb, void *insnp) for (e = new_bb->succ; e; e = e->succ_next) e->src = new_bb; - new_edge = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU); - if (bb->global_live_at_start) { new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); @@ -528,34 +521,7 @@ rtl_split_block (basic_block bb, void *insnp) #endif } - return new_edge; -} - -/* Assume that the code of basic block B has been merged into A. - Do corresponding CFG updates: redirect edges accordingly etc. */ -static void -update_cfg_after_block_merging (basic_block a, basic_block b) -{ - edge e; - - /* Normally there should only be one successor of A and that is B, but - partway though the merge of blocks for conditional_execution we'll - be merging a TEST block with THEN and ELSE successors. Free the - whole lot of them and hope the caller knows what they're doing. */ - while (a->succ) - remove_edge (a->succ); - - /* Adjust the edges out of B for the new owner. */ - for (e = b->succ; e; e = e->succ_next) - e->src = a; - a->succ = b->succ; - a->flags |= b->flags; - - /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ - b->pred = b->succ = NULL; - a->global_live_at_end = b->global_live_at_end; - - expunge_block (b); + return new_bb; } /* Blocks A and B are to be merged into a single block A. The insns @@ -625,10 +591,9 @@ rtl_merge_blocks (basic_block a, basic_block b) else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) del_first = NEXT_INSN (a_end); - update_cfg_after_block_merging (a, b); - /* Delete everything marked above as well as crap that might be hanging out between the two blocks. */ + BB_HEAD (b) = NULL; delete_insn_chain (del_first, del_last); /* Reassociate the insns of B with A. */ @@ -1159,10 +1124,16 @@ rtl_redirect_edge_and_branch_force (edge e, basic_block target) /* The given edge should potentially be a fallthru edge. If that is in fact true, delete the jump and barriers that are in the way. */ -void -tidy_fallthru_edge (edge e, basic_block b, basic_block c) +static void +rtl_tidy_fallthru_edge (edge e) { rtx q; + basic_block b = e->src, c = b->next_bb; + + /* If the jump insn has side effects, we can't tidy the edge. */ + if (GET_CODE (BB_END (b)) == JUMP_INSN + && !onlyjump_p (BB_END (b))) + return; /* ??? In a late-running flow pass, other folks may have deleted basic blocks by nopping out blocks, leaving multiple BARRIERs between here @@ -1208,48 +1179,6 @@ tidy_fallthru_edge (edge e, basic_block b, basic_block c) e->flags |= EDGE_FALLTHRU; } - -/* Fix up edges that now fall through, or rather should now fall through - but previously required a jump around now deleted blocks. Simplify - the search by only examining blocks numerically adjacent, since this - is how find_basic_blocks created them. */ - -void -tidy_fallthru_edges (void) -{ - basic_block b, c; - - if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) - return; - - FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb) - { - edge s; - - c = b->next_bb; - - /* We care about simple conditional or unconditional jumps with - a single successor. - - If we had a conditional branch to the next instruction when - find_basic_blocks was called, then there will only be one - out edge for the block which ended with the conditional - branch (since we do not create duplicate edges). - - Furthermore, the edge will be marked as a fallthru because we - merge the flags for the duplicate edges. So we do not want to - check that the edge is not a FALLTHRU edge. */ - - if ((s = b->succ) != NULL - && ! (s->flags & EDGE_COMPLEX) - && s->succ_next == NULL - && s->dest == c - /* If the jump insn has side effects, we can't tidy the edge. */ - && (GET_CODE (BB_END (b)) != JUMP_INSN - || onlyjump_p (BB_END (b)))) - tidy_fallthru_edge (s, b, c); - } -} /* Helper function for split_edge. Return true in case edge BB2 to BB1 is back edge of syntactic loop. */ @@ -1285,6 +1214,15 @@ back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) return count >= 0; } +/* Should move basic block BB after basic block AFTER. NIY. */ + +static bool +rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, + basic_block after ATTRIBUTE_UNUSED) +{ + return false; +} + /* Split a (typically critical) edge. Return the new block. Abort on abnormal edges. @@ -1347,8 +1285,6 @@ rtl_split_edge (edge edge_in) before = NULL_RTX; bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); - bb->count = edge_in->count; - bb->frequency = EDGE_FREQUENCY (edge_in); /* ??? This info is likely going to be out of date very soon. */ if (edge_in->dest->global_live_at_start) @@ -1714,15 +1650,21 @@ commit_edge_insertions_watch_calls (void) sbitmap_free (blocks); } -/* Print out one basic block with live information at start and end. */ +/* Print out RTL-specific basic block information (live information + at start and end). */ static void -rtl_dump_bb (basic_block bb, FILE *outf) +rtl_dump_bb (basic_block bb, FILE *outf, int indent) { rtx insn; rtx last; + char *s_indent; - fputs (";; Registers live at start:", outf); + s_indent = (char *) alloca ((size_t) indent + 1); + memset ((void *) s_indent, ' ', (size_t) indent); + s_indent[indent] = '\0'; + + fprintf (outf, ";;%s Registers live at start: ", s_indent); dump_regset (bb->global_live_at_start, outf); putc ('\n', outf); @@ -1730,7 +1672,7 @@ rtl_dump_bb (basic_block bb, FILE *outf) insn = NEXT_INSN (insn)) print_rtl_single (outf, insn); - fputs (";; Registers live at end:", outf); + fprintf (outf, ";;%s Registers live at end: ", s_indent); dump_regset (bb->global_live_at_end, outf); putc ('\n', outf); } @@ -1847,6 +1789,7 @@ update_br_prob_note (basic_block bb) In future it can be extended check a lot of other stuff as well (reachability of basic blocks, life information, etc. etc.). */ + static int rtl_verify_flow_info_1 (void) { @@ -2412,16 +2355,17 @@ purge_all_dead_edges (int update_life_p) } /* Same as split_block but update cfg_layout structures. */ -static edge + +static basic_block cfg_layout_split_block (basic_block bb, void *insnp) { rtx insn = insnp; + basic_block new_bb = rtl_split_block (bb, insn); - edge fallthru = rtl_split_block (bb, insn); + new_bb->rbi->footer = bb->rbi->footer; + bb->rbi->footer = NULL; - fallthru->dest->rbi->footer = fallthru->src->rbi->footer; - fallthru->src->rbi->footer = NULL; - return fallthru; + return new_bb; } @@ -2511,7 +2455,8 @@ cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) return NULL; } -/* Same as flow_delete_block but update cfg_layout structures. */ +/* Same as delete_basic_block but update cfg_layout structures. */ + static void cfg_layout_delete_block (basic_block bb) { @@ -2693,11 +2638,10 @@ cfg_layout_merge_blocks (basic_block a, basic_block b) if (rtl_dump_file) fprintf (rtl_dump_file, "Merged blocks %d and %d.\n", a->index, b->index); - - update_cfg_after_block_merging (a, b); } /* Split edge E. */ + static basic_block cfg_layout_split_edge (edge e) { @@ -2707,19 +2651,22 @@ cfg_layout_split_edge (edge e) ? NEXT_INSN (BB_END (e->src)) : get_insns (), NULL_RTX, e->src); - new_bb->count = e->count; - new_bb->frequency = EDGE_FREQUENCY (e); - new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); - new_e->probability = REG_BR_PROB_BASE; - new_e->count = e->count; redirect_edge_and_branch_force (e, new_bb); return new_bb; } +/* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ + +static void +rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) +{ +} + /* Implementation of CFG manipulation for linearized RTL. */ struct cfg_hooks rtl_cfg_hooks = { + "rtl", rtl_verify_flow_info, rtl_dump_bb, rtl_create_basic_block, @@ -2727,9 +2674,12 @@ struct cfg_hooks rtl_cfg_hooks = { rtl_redirect_edge_and_branch_force, rtl_delete_block, rtl_split_block, + rtl_move_block_after, rtl_can_merge_blocks, /* can_merge_blocks_p */ rtl_merge_blocks, - rtl_split_edge + rtl_split_edge, + rtl_make_forwarder_block, + rtl_tidy_fallthru_edge }; /* Implementation of CFG manipulation for cfg layout RTL, where @@ -2737,6 +2687,7 @@ struct cfg_hooks rtl_cfg_hooks = { This representation will hopefully become the default one in future version of the compiler. */ struct cfg_hooks cfg_layout_rtl_cfg_hooks = { + "cfglayout mode", rtl_verify_flow_info_1, rtl_dump_bb, cfg_layout_create_basic_block, @@ -2744,7 +2695,10 @@ struct cfg_hooks cfg_layout_rtl_cfg_hooks = { cfg_layout_redirect_edge_and_branch_force, cfg_layout_delete_block, cfg_layout_split_block, + rtl_move_block_after, cfg_layout_can_merge_blocks_p, cfg_layout_merge_blocks, - cfg_layout_split_edge + cfg_layout_split_edge, + rtl_make_forwarder_block, + NULL }; |
