X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fbb-reorder.c;h=a35b8e62942be478dfea5f9d79921578f3b7be83;hb=6d36105aaae27d356f305625f314a169d037cd1a;hp=74f93203f23c6fdadbd1257f9635cb0a4e361ccb;hpb=6fb33aa006ad25bb36d2ebec2ae2de101c63fed6;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c index 74f93203f23..a35b8e62942 100644 --- a/gcc/bb-reorder.c +++ b/gcc/bb-reorder.c @@ -1,11 +1,12 @@ /* Basic block reordering routines for the GNU compiler. - Copyright (C) 2000, 2002, 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, + 2012 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) + the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT @@ -14,9 +15,8 @@ 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, 59 Temple Place - Suite 330, Boston, MA - 02111-1307, USA. */ + along with GCC; see the file COPYING3. If not see + . */ /* This (greedy) algorithm constructs traces in several rounds. The construction starts from "seeds". The seed for the first round @@ -70,30 +70,57 @@ #include "coretypes.h" #include "tm.h" #include "rtl.h" -#include "basic-block.h" +#include "regs.h" #include "flags.h" #include "timevar.h" #include "output.h" #include "cfglayout.h" #include "fibheap.h" #include "target.h" +#include "function.h" +#include "tm_p.h" +#include "obstack.h" +#include "expr.h" +#include "params.h" +#include "diagnostic-core.h" +#include "toplev.h" /* user_defined_section_attribute */ +#include "tree-pass.h" +#include "df.h" +#include "bb-reorder.h" +#include "except.h" + +/* The number of rounds. In most cases there will only be 4 rounds, but + when partitioning hot and cold basic blocks into separate sections of + the .o file there will be an extra round.*/ +#define N_ROUNDS 5 + +/* Stubs in case we don't have a return insn. + We have to check at runtime too, not only compiletime. */ + +#ifndef HAVE_return +#define HAVE_return 0 +#define gen_return() NULL_RTX +#endif + + +struct target_bb_reorder default_target_bb_reorder; +#if SWITCHABLE_TARGET +struct target_bb_reorder *this_target_bb_reorder = &default_target_bb_reorder; +#endif -/* The number of rounds. */ -#define N_ROUNDS 4 +#define uncond_jump_length \ + (this_target_bb_reorder->x_uncond_jump_length) /* Branch thresholds in thousandths (per mille) of the REG_BR_PROB_BASE. */ -static int branch_threshold[N_ROUNDS] = {400, 200, 100, 0}; +static int branch_threshold[N_ROUNDS] = {400, 200, 100, 0, 0}; /* Exec thresholds in thousandths (per mille) of the frequency of bb 0. */ -static int exec_threshold[N_ROUNDS] = {500, 200, 50, 0}; +static int exec_threshold[N_ROUNDS] = {500, 200, 50, 0, 0}; /* If edge frequency is lower than DUPLICATION_THRESHOLD per mille of entry block the edge destination is not duplicated while connecting traces. */ #define DUPLICATION_THRESHOLD 100 -/* Length of unconditional jump instruction. */ -static int uncond_jump_length; - /* Structure to hold needed information for each basic block. */ typedef struct bbro_basic_block_data_def { @@ -103,6 +130,9 @@ typedef struct bbro_basic_block_data_def /* Which trace is the bb end of (-1 means it is not an end of a trace). */ int end_of_trace; + /* Which trace is the bb in? */ + int in_trace; + /* Which heap is BB in (if any)? */ fibheap_t heap; @@ -121,8 +151,7 @@ static bbro_basic_block_data *bbd; #define GET_ARRAY_SIZE(X) ((((X) / 4) + 1) * 5) /* Free the memory and set the pointer to NULL. */ -#define FREE(P) \ - do { if (P) { free (P); P = 0; } else { abort (); } } while (0) +#define FREE(P) (gcc_assert (P), free (P), P = 0) /* Structure for holding information about a trace. */ struct trace @@ -138,22 +167,50 @@ struct trace }; /* Maximum frequency and count of one of the entry blocks. */ -int max_entry_frequency; -gcov_type max_entry_count; +static int max_entry_frequency; +static gcov_type max_entry_count; /* Local function prototypes. */ static void find_traces (int *, struct trace *); static basic_block rotate_loop (edge, struct trace *, int); static void mark_bb_visited (basic_block, int); static void find_traces_1_round (int, int, gcov_type, struct trace *, int *, - int, fibheap_t *); + int, fibheap_t *, int); static basic_block copy_bb (basic_block, edge, basic_block, int); static fibheapkey_t bb_to_key (basic_block); -static bool better_edge_p (basic_block, edge, int, int, int, int); +static bool better_edge_p (const_basic_block, const_edge, int, int, int, int, const_edge); static void connect_traces (int, struct trace *); -static bool copy_bb_p (basic_block, int); -static int get_uncond_jump_length (void); +static bool copy_bb_p (const_basic_block, int); +static bool push_to_next_round_p (const_basic_block, int, int, int, gcov_type); +/* Check to see if bb should be pushed into the next round of trace + collections or not. Reasons for pushing the block forward are 1). + If the block is cold, we are doing partitioning, and there will be + another round (cold partition blocks are not supposed to be + collected into traces until the very last round); or 2). There will + be another round, and the basic block is not "hot enough" for the + current round of trace collection. */ + +static bool +push_to_next_round_p (const_basic_block bb, int round, int number_of_rounds, + int exec_th, gcov_type count_th) +{ + bool there_exists_another_round; + bool block_not_hot_enough; + + there_exists_another_round = round < number_of_rounds - 1; + + block_not_hot_enough = (bb->frequency < exec_th + || bb->count < count_th + || probably_never_executed_bb_p (bb)); + + if (there_exists_another_round + && block_not_hot_enough) + return true; + else + return false; +} + /* Find the traces for Software Trace Cache. Chain each trace through RBI()->next. Store the number of traces to N_TRACES and description of traces to TRACES. */ @@ -162,14 +219,22 @@ static void find_traces (int *n_traces, struct trace *traces) { int i; + int number_of_rounds; edge e; + edge_iterator ei; fibheap_t heap; + /* Add one extra round of trace collection when partitioning hot/cold + basic blocks into separate sections. The last round is for all the + cold blocks (and ONLY the cold blocks). */ + + number_of_rounds = N_ROUNDS - 1; + /* Insert entry points of function into heap. */ heap = fibheap_new (); max_entry_frequency = 0; max_entry_count = 0; - for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) { bbd[e->dest->index].heap = heap; bbd[e->dest->index].node = fibheap_insert (heap, bb_to_key (e->dest), @@ -181,7 +246,7 @@ find_traces (int *n_traces, struct trace *traces) } /* Find the traces. */ - for (i = 0; i < N_ROUNDS; i++) + for (i = 0; i < number_of_rounds; i++) { gcov_type count_threshold; @@ -195,7 +260,8 @@ find_traces (int *n_traces, struct trace *traces) find_traces_1_round (REG_BR_PROB_BASE * branch_threshold[i] / 1000, max_entry_frequency * exec_threshold[i] / 1000, - count_threshold, traces, n_traces, i, &heap); + count_threshold, traces, n_traces, i, &heap, + number_of_rounds); } fibheap_delete (heap); @@ -206,7 +272,7 @@ find_traces (int *n_traces, struct trace *traces) basic_block bb; fprintf (dump_file, "Trace %d (round %d): ", i + 1, traces[i].round + 1); - for (bb = traces[i].first; bb != traces[i].last; bb = bb->rbi->next) + for (bb = traces[i].first; bb != traces[i].last; bb = (basic_block) bb->aux) fprintf (dump_file, "%d [%d] ", bb->index, bb->frequency); fprintf (dump_file, "%d [%d]\n", bb->index, bb->frequency); } @@ -236,16 +302,18 @@ rotate_loop (edge back_edge, struct trace *trace, int trace_n) do { edge e; - for (e = bb->succ; e; e = e->succ_next) + edge_iterator ei; + + FOR_EACH_EDGE (e, ei, bb->succs) if (e->dest != EXIT_BLOCK_PTR - && e->dest->rbi->visited != trace_n + && e->dest->il.rtl->visited != trace_n && (e->flags & EDGE_CAN_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) { if (is_preferred) { /* The best edge is preferred. */ - if (!e->dest->rbi->visited + if (!e->dest->il.rtl->visited || bbd[e->dest->index].start_of_trace >= 0) { /* The current edge E is also preferred. */ @@ -261,7 +329,7 @@ rotate_loop (edge back_edge, struct trace *trace, int trace_n) } else { - if (!e->dest->rbi->visited + if (!e->dest->il.rtl->visited || bbd[e->dest->index].start_of_trace >= 0) { /* The current edge E is preferred. */ @@ -284,7 +352,7 @@ rotate_loop (edge back_edge, struct trace *trace, int trace_n) } } } - bb = bb->rbi->next; + bb = (basic_block) bb->aux; } while (bb != back_edge->dest); @@ -294,29 +362,29 @@ rotate_loop (edge back_edge, struct trace *trace, int trace_n) the trace. */ if (back_edge->dest == trace->first) { - trace->first = best_bb->rbi->next; + trace->first = (basic_block) best_bb->aux; } else { basic_block prev_bb; for (prev_bb = trace->first; - prev_bb->rbi->next != back_edge->dest; - prev_bb = prev_bb->rbi->next) + prev_bb->aux != back_edge->dest; + prev_bb = (basic_block) prev_bb->aux) ; - prev_bb->rbi->next = best_bb->rbi->next; + prev_bb->aux = best_bb->aux; /* Try to get rid of uncond jump to cond jump. */ - if (prev_bb->succ && !prev_bb->succ->succ_next) + if (single_succ_p (prev_bb)) { - basic_block header = prev_bb->succ->dest; + basic_block header = single_succ (prev_bb); /* Duplicate HEADER if it is a small block containing cond jump in the end. */ - if (any_condjump_p (BB_END (header)) && copy_bb_p (header, 0)) - { - copy_bb (header, prev_bb->succ, prev_bb, trace_n); - } + if (any_condjump_p (BB_END (header)) && copy_bb_p (header, 0) + && !find_reg_note (BB_END (header), REG_CROSSING_JUMP, + NULL_RTX)) + copy_bb (header, single_succ_edge (prev_bb), prev_bb, trace_n); } } } @@ -325,7 +393,7 @@ rotate_loop (edge back_edge, struct trace *trace, int trace_n) /* We have not found suitable loop tail so do no rotation. */ best_bb = back_edge->src; } - best_bb->rbi->next = NULL; + best_bb->aux = NULL; return best_bb; } @@ -334,7 +402,7 @@ rotate_loop (edge back_edge, struct trace *trace, int trace_n) static void mark_bb_visited (basic_block bb, int trace) { - bb->rbi->visited = trace; + bb->il.rtl->visited = trace; if (bbd[bb->index].heap) { fibheap_delete_node (bbd[bb->index].heap, bbd[bb->index].node); @@ -354,7 +422,7 @@ mark_bb_visited (basic_block bb, int trace) static void find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, struct trace *traces, int *n_traces, int round, - fibheap_t *heap) + fibheap_t *heap, int number_of_rounds) { /* Heap for discarded basic blocks which are possible starting points for the next round. */ @@ -366,18 +434,22 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, struct trace *trace; edge best_edge, e; fibheapkey_t key; + edge_iterator ei; - bb = fibheap_extract_min (*heap); + bb = (basic_block) fibheap_extract_min (*heap); bbd[bb->index].heap = NULL; bbd[bb->index].node = NULL; if (dump_file) fprintf (dump_file, "Getting bb %d\n", bb->index); - /* If the BB's frequency is too low send BB to the next round. */ - if (round < N_ROUNDS - 1 - && (bb->frequency < exec_th || bb->count < count_th - || probably_never_executed_bb_p (bb))) + /* If the BB's frequency is too low send BB to the next round. When + partitioning hot/cold blocks into separate sections, make sure all + the cold blocks (and ONLY the cold blocks) go into the (extra) final + round. */ + + if (push_to_next_round_p (bb, round, number_of_rounds, exec_th, + count_th)) { int key = bb_to_key (bb); bbd[bb->index].heap = new_heap; @@ -394,11 +466,13 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, trace->first = bb; trace->round = round; trace->length = 0; + bbd[bb->index].in_trace = *n_traces; (*n_traces)++; do { int prob, freq; + bool ends_in_call; /* The probability and frequency of the best edge. */ int best_prob = INT_MIN / 2; @@ -412,31 +486,51 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, fprintf (dump_file, "Basic block %d was visited in trace %d\n", bb->index, *n_traces - 1); + ends_in_call = block_ends_with_call_p (bb); + /* Select the successor that will be placed after BB. */ - for (e = bb->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, bb->succs) { -#ifdef ENABLE_CHECKING - if (e->flags & EDGE_FAKE) - abort (); -#endif + gcc_assert (!(e->flags & EDGE_FAKE)); if (e->dest == EXIT_BLOCK_PTR) continue; - if (e->dest->rbi->visited - && e->dest->rbi->visited != *n_traces) + if (e->dest->il.rtl->visited + && e->dest->il.rtl->visited != *n_traces) + continue; + + if (BB_PARTITION (e->dest) != BB_PARTITION (bb)) continue; prob = e->probability; - freq = EDGE_FREQUENCY (e); + freq = e->dest->frequency; + + /* The only sensible preference for a call instruction is the + fallthru edge. Don't bother selecting anything else. */ + if (ends_in_call) + { + if (e->flags & EDGE_CAN_FALLTHRU) + { + best_edge = e; + best_prob = prob; + best_freq = freq; + } + continue; + } /* Edge that cannot be fallthru or improbable or infrequent - successor (ie. it is unsuitable successor). */ + successor (i.e. it is unsuitable successor). */ if (!(e->flags & EDGE_CAN_FALLTHRU) || (e->flags & EDGE_COMPLEX) - || prob < branch_th || freq < exec_th || e->count < count_th) + || prob < branch_th || EDGE_FREQUENCY (e) < exec_th + || e->count < count_th) continue; - if (better_edge_p (bb, e, prob, freq, best_prob, best_freq)) + /* If partitioning hot/cold basic blocks, don't consider edges + that cross section boundaries. */ + + if (better_edge_p (bb, e, prob, freq, best_prob, best_freq, + best_edge)) { best_edge = e; best_prob = prob; @@ -447,16 +541,16 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, /* If the best destination has multiple predecessors, and can be duplicated cheaper than a jump, don't allow it to be added to a trace. We'll duplicate it when connecting traces. */ - if (best_edge && best_edge->dest->pred->pred_next + if (best_edge && EDGE_COUNT (best_edge->dest->preds) >= 2 && copy_bb_p (best_edge->dest, 0)) best_edge = NULL; /* Add all non-selected successors to the heaps. */ - for (e = bb->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, bb->succs) { if (e == best_edge || e->dest == EXIT_BLOCK_PTR - || e->dest->rbi->visited) + || e->dest->il.rtl->visited) continue; key = bb_to_key (e->dest); @@ -490,7 +584,13 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, || prob < branch_th || freq < exec_th || e->count < count_th) { - if (round < N_ROUNDS - 1) + /* When partitioning hot/cold basic blocks, make sure + the cold blocks (and only the cold blocks) all get + pushed to the last round of trace collection. */ + + if (push_to_next_round_p (e->dest, round, + number_of_rounds, + exec_th, count_th)) which_heap = new_heap; } @@ -511,7 +611,7 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, if (best_edge) /* Suitable successor was found. */ { - if (best_edge->dest->rbi->visited == *n_traces) + if (best_edge->dest->il.rtl->visited == *n_traces) { /* We do nothing with one basic block loops. */ if (best_edge->dest != bb) @@ -531,7 +631,9 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, "Rotating loop %d - %d\n", best_edge->dest->index, bb->index); } - bb->rbi->next = best_edge->dest; + bb->aux = best_edge->dest; + bbd[best_edge->dest->index].in_trace = + (*n_traces) - 1; bb = rotate_loop (best_edge, trace, *n_traces); } } @@ -539,19 +641,13 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, { /* The loop has less than 4 iterations. */ - /* Check whether there is another edge from BB. */ - edge another_edge; - for (another_edge = bb->succ; - another_edge; - another_edge = another_edge->succ_next) - if (another_edge != best_edge) - break; - - if (!another_edge && copy_bb_p (best_edge->dest, - !optimize_size)) + if (single_succ_p (bb) + && copy_bb_p (best_edge->dest, + optimize_edge_for_speed_p (best_edge))) { bb = copy_bb (best_edge->dest, best_edge, bb, *n_traces); + trace->length++; } } } @@ -582,17 +678,18 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, */ - for (e = bb->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, bb->succs) if (e != best_edge && (e->flags & EDGE_CAN_FALLTHRU) && !(e->flags & EDGE_COMPLEX) - && !e->dest->rbi->visited - && !e->dest->pred->pred_next - && e->dest->succ - && (e->dest->succ->flags & EDGE_CAN_FALLTHRU) - && !(e->dest->succ->flags & EDGE_COMPLEX) - && !e->dest->succ->succ_next - && e->dest->succ->dest == best_edge->dest + && !e->dest->il.rtl->visited + && single_pred_p (e->dest) + && !(e->flags & EDGE_CROSSING) + && single_succ_p (e->dest) + && (single_succ_edge (e->dest)->flags + & EDGE_CAN_FALLTHRU) + && !(single_succ_edge (e->dest)->flags & EDGE_COMPLEX) + && single_succ (e->dest) == best_edge->dest && 2 * e->dest->frequency >= EDGE_FREQUENCY (best_edge)) { best_edge = e; @@ -602,7 +699,8 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, break; } - bb->rbi->next = best_edge->dest; + bb->aux = best_edge->dest; + bbd[best_edge->dest->index].in_trace = (*n_traces) - 1; bb = best_edge->dest; } } @@ -615,10 +713,10 @@ find_traces_1_round (int branch_th, int exec_th, gcov_type count_th, /* The trace is terminated so we have to recount the keys in heap (some block can have a lower key because now one of its predecessors is an end of the trace). */ - for (e = bb->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, bb->succs) { if (e->dest == EXIT_BLOCK_PTR - || e->dest->rbi->visited) + || e->dest->il.rtl->visited) continue; if (bbd[e->dest->index].heap) @@ -656,18 +754,19 @@ copy_bb (basic_block old_bb, edge e, basic_block bb, int trace) { basic_block new_bb; - new_bb = cfg_layout_duplicate_bb (old_bb, e); - if (e->dest != new_bb) - abort (); - if (e->dest->rbi->visited) - abort (); + new_bb = duplicate_block (old_bb, e, bb); + BB_COPY_PARTITION (new_bb, old_bb); + + gcc_assert (e->dest == new_bb); + gcc_assert (!e->dest->il.rtl->visited); + if (dump_file) fprintf (dump_file, "Duplicated bb %d (created bb %d)\n", old_bb->index, new_bb->index); - new_bb->rbi->visited = trace; - new_bb->rbi->next = bb->rbi->next; - bb->rbi->next = new_bb; + new_bb->il.rtl->visited = trace; + new_bb->aux = bb->aux; + bb->aux = new_bb; if (new_bb->index >= array_size || last_basic_block > array_size) { @@ -676,10 +775,11 @@ copy_bb (basic_block old_bb, edge e, basic_block bb, int trace) new_size = MAX (last_basic_block, new_bb->index + 1); new_size = GET_ARRAY_SIZE (new_size); - bbd = xrealloc (bbd, new_size * sizeof (bbro_basic_block_data)); + bbd = XRESIZEVEC (bbro_basic_block_data, bbd, new_size); for (i = array_size; i < new_size; i++) { bbd[i].start_of_trace = -1; + bbd[i].in_trace = -1; bbd[i].end_of_trace = -1; bbd[i].heap = NULL; bbd[i].node = NULL; @@ -694,6 +794,8 @@ copy_bb (basic_block old_bb, edge e, basic_block bb, int trace) } } + bbd[new_bb->index].in_trace = trace; + return new_bb; } @@ -703,16 +805,18 @@ static fibheapkey_t bb_to_key (basic_block bb) { edge e; - + edge_iterator ei; int priority = 0; /* Do not start in probably never executed blocks. */ - if (probably_never_executed_bb_p (bb)) + + if (BB_PARTITION (bb) == BB_COLD_PARTITION + || probably_never_executed_bb_p (bb)) return BB_FREQ_MAX; /* Prefer blocks whose predecessor is an end of some trace or whose predecessor edge is EDGE_DFS_BACK. */ - for (e = bb->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, bb->preds) { if ((e->src != ENTRY_BLOCK_PTR && bbd[e->src->index].end_of_trace >= 0) || (e->flags & EDGE_DFS_BACK)) @@ -738,8 +842,8 @@ bb_to_key (basic_block bb) BEST_PROB; similarly for frequency. */ static bool -better_edge_p (basic_block bb, edge e, int prob, int freq, int best_prob, - int best_freq) +better_edge_p (const_basic_block bb, const_edge e, int prob, int freq, int best_prob, + int best_freq, const_edge cur_best_edge) { bool is_better_edge; @@ -770,6 +874,16 @@ better_edge_p (basic_block bb, edge e, int prob, int freq, int best_prob, else is_better_edge = false; + /* If we are doing hot/cold partitioning, make sure that we always favor + non-crossing edges over crossing edges. */ + + if (!is_better_edge + && flag_reorder_blocks_and_partition + && cur_best_edge + && (cur_best_edge->flags & EDGE_CROSSING) + && !(e->flags & EDGE_CROSSING)) + is_better_edge = true; + return is_better_edge; } @@ -780,7 +894,10 @@ connect_traces (int n_traces, struct trace *traces) { int i; bool *connected; + bool two_passes; int last_trace; + int current_pass; + int current_partition; int freq_threshold; gcov_type count_threshold; @@ -790,26 +907,53 @@ connect_traces (int n_traces, struct trace *traces) else count_threshold = max_entry_count / 1000 * DUPLICATION_THRESHOLD; - connected = xcalloc (n_traces, sizeof (bool)); + connected = XCNEWVEC (bool, n_traces); last_trace = -1; - for (i = 0; i < n_traces; i++) + current_pass = 1; + current_partition = BB_PARTITION (traces[0].first); + two_passes = false; + + if (flag_reorder_blocks_and_partition) + for (i = 0; i < n_traces && !two_passes; i++) + if (BB_PARTITION (traces[0].first) + != BB_PARTITION (traces[i].first)) + two_passes = true; + + for (i = 0; i < n_traces || (two_passes && current_pass == 1) ; i++) { int t = i; int t2; edge e, best; int best_len; + if (i >= n_traces) + { + gcc_assert (two_passes && current_pass == 1); + i = 0; + t = i; + current_pass = 2; + if (current_partition == BB_HOT_PARTITION) + current_partition = BB_COLD_PARTITION; + else + current_partition = BB_HOT_PARTITION; + } + if (connected[t]) continue; + if (two_passes + && BB_PARTITION (traces[t].first) != current_partition) + continue; + connected[t] = true; /* Find the predecessor traces. */ for (t2 = t; t2 > 0;) { + edge_iterator ei; best = NULL; best_len = 0; - for (e = traces[t2].first->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, traces[t2].first->preds) { int si = e->src->index; @@ -818,6 +962,7 @@ connect_traces (int n_traces, struct trace *traces) && !(e->flags & EDGE_COMPLEX) && bbd[si].end_of_trace >= 0 && !connected[bbd[si].end_of_trace] + && (BB_PARTITION (e->src) == current_partition) && (!best || e->probability > best->probability || (e->probability == best->probability @@ -829,9 +974,10 @@ connect_traces (int n_traces, struct trace *traces) } if (best) { - best->src->rbi->next = best->dest; + best->src->aux = best->dest; t2 = bbd[best->src->index].end_of_trace; connected[t2] = true; + if (dump_file) { fprintf (dump_file, "Connection: %d %d\n", @@ -843,16 +989,17 @@ connect_traces (int n_traces, struct trace *traces) } if (last_trace >= 0) - traces[last_trace].last->rbi->next = traces[t2].first; + traces[last_trace].last->aux = traces[t2].first; last_trace = t; /* Find the successor traces. */ while (1) { /* Find the continuation of the chain. */ + edge_iterator ei; best = NULL; best_len = 0; - for (e = traces[t].last->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, traces[t].last->succs) { int di = e->dest->index; @@ -861,6 +1008,7 @@ connect_traces (int n_traces, struct trace *traces) && !(e->flags & EDGE_COMPLEX) && bbd[di].start_of_trace >= 0 && !connected[bbd[di].start_of_trace] + && (BB_PARTITION (e->dest) == current_partition) && (!best || e->probability > best->probability || (e->probability == best->probability @@ -879,7 +1027,7 @@ connect_traces (int n_traces, struct trace *traces) best->src->index, best->dest->index); } t = bbd[best->dest->index].start_of_trace; - traces[last_trace].last->rbi->next = traces[t].first; + traces[last_trace].last->aux = traces[t].first; connected[t] = true; last_trace = t; } @@ -890,12 +1038,13 @@ connect_traces (int n_traces, struct trace *traces) basic_block next_bb = NULL; bool try_copy = false; - for (e = traces[t].last->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, traces[t].last->succs) if (e->dest != EXIT_BLOCK_PTR && (e->flags & EDGE_CAN_FALLTHRU) && !(e->flags & EDGE_COMPLEX) && (!best || e->probability > best->probability)) { + edge_iterator ei; edge best2 = NULL; int best2_len = 0; @@ -911,7 +1060,7 @@ connect_traces (int n_traces, struct trace *traces) continue; } - for (e2 = e->dest->succ; e2; e2 = e2->succ_next) + FOR_EACH_EDGE (e2, ei, e->dest->succs) { int di = e2->dest->index; @@ -920,6 +1069,7 @@ connect_traces (int n_traces, struct trace *traces) && !(e2->flags & EDGE_COMPLEX) && bbd[di].start_of_trace >= 0 && !connected[bbd[di].start_of_trace] + && (BB_PARTITION (e2->dest) == current_partition) && (EDGE_FREQUENCY (e2) >= freq_threshold) && (e2->count >= count_threshold) && (!best2 @@ -940,11 +1090,14 @@ connect_traces (int n_traces, struct trace *traces) } } + if (flag_reorder_blocks_and_partition) + try_copy = false; + /* Copy tiny blocks always; copy larger blocks only when the edge is traversed frequently enough. */ if (try_copy && copy_bb_p (best->dest, - !optimize_size + optimize_edge_for_speed_p (best) && EDGE_FREQUENCY (best) >= freq_threshold && best->count >= count_threshold)) { @@ -967,7 +1120,7 @@ connect_traces (int n_traces, struct trace *traces) if (next_bb && next_bb != EXIT_BLOCK_PTR) { t = bbd[next_bb->index].start_of_trace; - traces[last_trace].last->rbi->next = traces[t].first; + traces[last_trace].last->aux = traces[t].first; connected[t] = true; last_trace = t; } @@ -985,7 +1138,7 @@ connect_traces (int n_traces, struct trace *traces) basic_block bb; fprintf (dump_file, "Final order:\n"); - for (bb = traces[0].first; bb; bb = bb->rbi->next) + for (bb = traces[0].first; bb; bb = (basic_block) bb->aux) fprintf (dump_file, "%d ", bb->index); fprintf (dump_file, "\n"); fflush (dump_file); @@ -998,38 +1151,30 @@ connect_traces (int n_traces, struct trace *traces) when code size is allowed to grow by duplication. */ static bool -copy_bb_p (basic_block bb, int code_may_grow) +copy_bb_p (const_basic_block bb, int code_may_grow) { int size = 0; int max_size = uncond_jump_length; rtx insn; - int n_succ; - edge e; if (!bb->frequency) return false; - if (!bb->pred || !bb->pred->pred_next) + if (EDGE_COUNT (bb->preds) < 2) return false; - if (!cfg_layout_can_duplicate_bb_p (bb)) + if (!can_duplicate_block_p (bb)) return false; /* Avoid duplicating blocks which have many successors (PR/13430). */ - n_succ = 0; - for (e = bb->succ; e; e = e->succ_next) - { - n_succ++; - if (n_succ > 8) - return false; - } + if (EDGE_COUNT (bb->succs) > 8) + return false; - if (code_may_grow && maybe_hot_bb_p (bb)) - max_size *= 8; + if (code_may_grow && optimize_bb_for_speed_p (bb)) + max_size *= PARAM_VALUE (PARAM_MAX_GROW_COPY_BB_INSNS); - for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb)); - insn = NEXT_INSN (insn)) + FOR_BB_INSNS (bb, insn) { if (INSN_P (insn)) - size += get_attr_length (insn); + size += get_attr_min_length (insn); } if (size <= max_size) @@ -1047,7 +1192,7 @@ copy_bb_p (basic_block bb, int code_may_grow) /* Return the length of unconditional jump instruction. */ -static int +int get_uncond_jump_length (void) { rtx label, jump; @@ -1056,14 +1201,707 @@ get_uncond_jump_length (void) label = emit_label_before (gen_label_rtx (), get_insns ()); jump = emit_jump_insn (gen_jump (label)); - length = get_attr_length (jump); + length = get_attr_min_length (jump); delete_insn (jump); delete_insn (label); return length; } -/* Reorder basic blocks. The main entry point to this file. */ +/* Emit a barrier into the footer of BB. */ + +static void +emit_barrier_after_bb (basic_block bb) +{ + rtx barrier = emit_barrier_after (BB_END (bb)); + bb->il.rtl->footer = unlink_insn_chain (barrier, barrier); +} + +/* The landing pad OLD_LP, in block OLD_BB, has edges from both partitions. + Duplicate the landing pad and split the edges so that no EH edge + crosses partitions. */ + +static void +fix_up_crossing_landing_pad (eh_landing_pad old_lp, basic_block old_bb) +{ + eh_landing_pad new_lp; + basic_block new_bb, last_bb, post_bb; + rtx new_label, jump, post_label; + unsigned new_partition; + edge_iterator ei; + edge e; + + /* Generate the new landing-pad structure. */ + new_lp = gen_eh_landing_pad (old_lp->region); + new_lp->post_landing_pad = old_lp->post_landing_pad; + new_lp->landing_pad = gen_label_rtx (); + LABEL_PRESERVE_P (new_lp->landing_pad) = 1; + + /* Put appropriate instructions in new bb. */ + new_label = emit_label (new_lp->landing_pad); + + expand_dw2_landing_pad_for_region (old_lp->region); + + post_bb = BLOCK_FOR_INSN (old_lp->landing_pad); + post_bb = single_succ (post_bb); + post_label = block_label (post_bb); + jump = emit_jump_insn (gen_jump (post_label)); + JUMP_LABEL (jump) = post_label; + + /* Create new basic block to be dest for lp. */ + last_bb = EXIT_BLOCK_PTR->prev_bb; + new_bb = create_basic_block (new_label, jump, last_bb); + new_bb->aux = last_bb->aux; + last_bb->aux = new_bb; + + emit_barrier_after_bb (new_bb); + + make_edge (new_bb, post_bb, 0); + + /* Make sure new bb is in the other partition. */ + new_partition = BB_PARTITION (old_bb); + new_partition ^= BB_HOT_PARTITION | BB_COLD_PARTITION; + BB_SET_PARTITION (new_bb, new_partition); + + /* Fix up the edges. */ + for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)) != NULL; ) + if (BB_PARTITION (e->src) == new_partition) + { + rtx insn = BB_END (e->src); + rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); + + gcc_assert (note != NULL); + gcc_checking_assert (INTVAL (XEXP (note, 0)) == old_lp->index); + XEXP (note, 0) = GEN_INT (new_lp->index); + + /* Adjust the edge to the new destination. */ + redirect_edge_succ (e, new_bb); + } + else + ei_next (&ei); +} + +/* Find the basic blocks that are rarely executed and need to be moved to + a separate section of the .o file (to cut down on paging and improve + cache locality). Return a vector of all edges that cross. */ + +static VEC(edge, heap) * +find_rarely_executed_basic_blocks_and_crossing_edges (void) +{ + VEC(edge, heap) *crossing_edges = NULL; + basic_block bb; + edge e; + edge_iterator ei; + + /* Mark which partition (hot/cold) each basic block belongs in. */ + FOR_EACH_BB (bb) + { + if (probably_never_executed_bb_p (bb)) + BB_SET_PARTITION (bb, BB_COLD_PARTITION); + else + BB_SET_PARTITION (bb, BB_HOT_PARTITION); + } + + /* The format of .gcc_except_table does not allow landing pads to + be in a different partition as the throw. Fix this by either + moving or duplicating the landing pads. */ + if (cfun->eh->lp_array) + { + unsigned i; + eh_landing_pad lp; + + FOR_EACH_VEC_ELT (eh_landing_pad, cfun->eh->lp_array, i, lp) + { + bool all_same, all_diff; + + if (lp == NULL + || lp->landing_pad == NULL_RTX + || !LABEL_P (lp->landing_pad)) + continue; + + all_same = all_diff = true; + bb = BLOCK_FOR_INSN (lp->landing_pad); + FOR_EACH_EDGE (e, ei, bb->preds) + { + gcc_assert (e->flags & EDGE_EH); + if (BB_PARTITION (bb) == BB_PARTITION (e->src)) + all_diff = false; + else + all_same = false; + } + + if (all_same) + ; + else if (all_diff) + { + int which = BB_PARTITION (bb); + which ^= BB_HOT_PARTITION | BB_COLD_PARTITION; + BB_SET_PARTITION (bb, which); + } + else + fix_up_crossing_landing_pad (lp, bb); + } + } + + /* Mark every edge that crosses between sections. */ + + FOR_EACH_BB (bb) + FOR_EACH_EDGE (e, ei, bb->succs) + { + unsigned int flags = e->flags; + + /* We should never have EDGE_CROSSING set yet. */ + gcc_checking_assert ((flags & EDGE_CROSSING) == 0); + + if (e->src != ENTRY_BLOCK_PTR + && e->dest != EXIT_BLOCK_PTR + && BB_PARTITION (e->src) != BB_PARTITION (e->dest)) + { + VEC_safe_push (edge, heap, crossing_edges, e); + flags |= EDGE_CROSSING; + } + + /* Now that we've split eh edges as appropriate, allow landing pads + to be merged with the post-landing pads. */ + flags &= ~EDGE_PRESERVE; + + e->flags = flags; + } + + return crossing_edges; +} + +/* If any destination of a crossing edge does not have a label, add label; + Convert any easy fall-through crossing edges to unconditional jumps. */ + +static void +add_labels_and_missing_jumps (VEC(edge, heap) *crossing_edges) +{ + size_t i; + edge e; + + FOR_EACH_VEC_ELT (edge, crossing_edges, i, e) + { + basic_block src = e->src; + basic_block dest = e->dest; + rtx label, new_jump; + + if (dest == EXIT_BLOCK_PTR) + continue; + + /* Make sure dest has a label. */ + label = block_label (dest); + + /* Nothing to do for non-fallthru edges. */ + if (src == ENTRY_BLOCK_PTR) + continue; + if ((e->flags & EDGE_FALLTHRU) == 0) + continue; + + /* If the block does not end with a control flow insn, then we + can trivially add a jump to the end to fixup the crossing. + Otherwise the jump will have to go in a new bb, which will + be handled by fix_up_fall_thru_edges function. */ + if (control_flow_insn_p (BB_END (src))) + continue; + + /* Make sure there's only one successor. */ + gcc_assert (single_succ_p (src)); + + new_jump = emit_jump_insn_after (gen_jump (label), BB_END (src)); + BB_END (src) = new_jump; + JUMP_LABEL (new_jump) = label; + LABEL_NUSES (label) += 1; + + emit_barrier_after_bb (src); + + /* Mark edge as non-fallthru. */ + e->flags &= ~EDGE_FALLTHRU; + } +} + +/* Find any bb's where the fall-through edge is a crossing edge (note that + these bb's must also contain a conditional jump or end with a call + instruction; we've already dealt with fall-through edges for blocks + that didn't have a conditional jump or didn't end with call instruction + in the call to add_labels_and_missing_jumps). Convert the fall-through + edge to non-crossing edge by inserting a new bb to fall-through into. + The new bb will contain an unconditional jump (crossing edge) to the + original fall through destination. */ + +static void +fix_up_fall_thru_edges (void) +{ + basic_block cur_bb; + basic_block new_bb; + edge succ1; + edge succ2; + edge fall_thru; + edge cond_jump = NULL; + edge e; + bool cond_jump_crosses; + int invert_worked; + rtx old_jump; + rtx fall_thru_label; + + FOR_EACH_BB (cur_bb) + { + fall_thru = NULL; + if (EDGE_COUNT (cur_bb->succs) > 0) + succ1 = EDGE_SUCC (cur_bb, 0); + else + succ1 = NULL; + + if (EDGE_COUNT (cur_bb->succs) > 1) + succ2 = EDGE_SUCC (cur_bb, 1); + else + succ2 = NULL; + + /* Find the fall-through edge. */ + + if (succ1 + && (succ1->flags & EDGE_FALLTHRU)) + { + fall_thru = succ1; + cond_jump = succ2; + } + else if (succ2 + && (succ2->flags & EDGE_FALLTHRU)) + { + fall_thru = succ2; + cond_jump = succ1; + } + else if (succ1 + && (block_ends_with_call_p (cur_bb) + || can_throw_internal (BB_END (cur_bb)))) + { + edge e; + edge_iterator ei; + + /* Find EDGE_CAN_FALLTHRU edge. */ + FOR_EACH_EDGE (e, ei, cur_bb->succs) + if (e->flags & EDGE_CAN_FALLTHRU) + { + fall_thru = e; + break; + } + } + + if (fall_thru && (fall_thru->dest != EXIT_BLOCK_PTR)) + { + /* Check to see if the fall-thru edge is a crossing edge. */ + + if (fall_thru->flags & EDGE_CROSSING) + { + /* The fall_thru edge crosses; now check the cond jump edge, if + it exists. */ + + cond_jump_crosses = true; + invert_worked = 0; + old_jump = BB_END (cur_bb); + + /* Find the jump instruction, if there is one. */ + + if (cond_jump) + { + if (!(cond_jump->flags & EDGE_CROSSING)) + cond_jump_crosses = false; + + /* We know the fall-thru edge crosses; if the cond + jump edge does NOT cross, and its destination is the + next block in the bb order, invert the jump + (i.e. fix it so the fall thru does not cross and + the cond jump does). */ + + if (!cond_jump_crosses + && cur_bb->aux == cond_jump->dest) + { + /* Find label in fall_thru block. We've already added + any missing labels, so there must be one. */ + + fall_thru_label = block_label (fall_thru->dest); + + if (old_jump && JUMP_P (old_jump) && fall_thru_label) + invert_worked = invert_jump (old_jump, + fall_thru_label,0); + if (invert_worked) + { + fall_thru->flags &= ~EDGE_FALLTHRU; + cond_jump->flags |= EDGE_FALLTHRU; + update_br_prob_note (cur_bb); + e = fall_thru; + fall_thru = cond_jump; + cond_jump = e; + cond_jump->flags |= EDGE_CROSSING; + fall_thru->flags &= ~EDGE_CROSSING; + } + } + } + + if (cond_jump_crosses || !invert_worked) + { + /* This is the case where both edges out of the basic + block are crossing edges. Here we will fix up the + fall through edge. The jump edge will be taken care + of later. The EDGE_CROSSING flag of fall_thru edge + is unset before the call to force_nonfallthru + function because if a new basic-block is created + this edge remains in the current section boundary + while the edge between new_bb and the fall_thru->dest + becomes EDGE_CROSSING. */ + + fall_thru->flags &= ~EDGE_CROSSING; + new_bb = force_nonfallthru (fall_thru); + + if (new_bb) + { + new_bb->aux = cur_bb->aux; + cur_bb->aux = new_bb; + + /* Make sure new fall-through bb is in same + partition as bb it's falling through from. */ + + BB_COPY_PARTITION (new_bb, cur_bb); + single_succ_edge (new_bb)->flags |= EDGE_CROSSING; + } + else + { + /* If a new basic-block was not created; restore + the EDGE_CROSSING flag. */ + fall_thru->flags |= EDGE_CROSSING; + } + + /* Add barrier after new jump */ + emit_barrier_after_bb (new_bb ? new_bb : cur_bb); + } + } + } + } +} + +/* This function checks the destination block of a "crossing jump" to + see if it has any crossing predecessors that begin with a code label + and end with an unconditional jump. If so, it returns that predecessor + block. (This is to avoid creating lots of new basic blocks that all + contain unconditional jumps to the same destination). */ + +static basic_block +find_jump_block (basic_block jump_dest) +{ + basic_block source_bb = NULL; + edge e; + rtx insn; + edge_iterator ei; + + FOR_EACH_EDGE (e, ei, jump_dest->preds) + if (e->flags & EDGE_CROSSING) + { + basic_block src = e->src; + + /* Check each predecessor to see if it has a label, and contains + only one executable instruction, which is an unconditional jump. + If so, we can use it. */ + + if (LABEL_P (BB_HEAD (src))) + for (insn = BB_HEAD (src); + !INSN_P (insn) && insn != NEXT_INSN (BB_END (src)); + insn = NEXT_INSN (insn)) + { + if (INSN_P (insn) + && insn == BB_END (src) + && JUMP_P (insn) + && !any_condjump_p (insn)) + { + source_bb = src; + break; + } + } + + if (source_bb) + break; + } + + return source_bb; +} + +/* Find all BB's with conditional jumps that are crossing edges; + insert a new bb and make the conditional jump branch to the new + bb instead (make the new bb same color so conditional branch won't + be a 'crossing' edge). Insert an unconditional jump from the + new bb to the original destination of the conditional jump. */ + +static void +fix_crossing_conditional_branches (void) +{ + basic_block cur_bb; + basic_block new_bb; + basic_block dest; + edge succ1; + edge succ2; + edge crossing_edge; + edge new_edge; + rtx old_jump; + rtx set_src; + rtx old_label = NULL_RTX; + rtx new_label; + + FOR_EACH_BB (cur_bb) + { + crossing_edge = NULL; + if (EDGE_COUNT (cur_bb->succs) > 0) + succ1 = EDGE_SUCC (cur_bb, 0); + else + succ1 = NULL; + + if (EDGE_COUNT (cur_bb->succs) > 1) + succ2 = EDGE_SUCC (cur_bb, 1); + else + succ2 = NULL; + + /* We already took care of fall-through edges, so only one successor + can be a crossing edge. */ + + if (succ1 && (succ1->flags & EDGE_CROSSING)) + crossing_edge = succ1; + else if (succ2 && (succ2->flags & EDGE_CROSSING)) + crossing_edge = succ2; + + if (crossing_edge) + { + old_jump = BB_END (cur_bb); + + /* Check to make sure the jump instruction is a + conditional jump. */ + + set_src = NULL_RTX; + + if (any_condjump_p (old_jump)) + { + if (GET_CODE (PATTERN (old_jump)) == SET) + set_src = SET_SRC (PATTERN (old_jump)); + else if (GET_CODE (PATTERN (old_jump)) == PARALLEL) + { + set_src = XVECEXP (PATTERN (old_jump), 0,0); + if (GET_CODE (set_src) == SET) + set_src = SET_SRC (set_src); + else + set_src = NULL_RTX; + } + } + + if (set_src && (GET_CODE (set_src) == IF_THEN_ELSE)) + { + if (GET_CODE (XEXP (set_src, 1)) == PC) + old_label = XEXP (set_src, 2); + else if (GET_CODE (XEXP (set_src, 2)) == PC) + old_label = XEXP (set_src, 1); + + /* Check to see if new bb for jumping to that dest has + already been created; if so, use it; if not, create + a new one. */ + + new_bb = find_jump_block (crossing_edge->dest); + + if (new_bb) + new_label = block_label (new_bb); + else + { + basic_block last_bb; + rtx new_jump; + + /* Create new basic block to be dest for + conditional jump. */ + + /* Put appropriate instructions in new bb. */ + + new_label = gen_label_rtx (); + emit_label (new_label); + + gcc_assert (GET_CODE (old_label) == LABEL_REF); + old_label = JUMP_LABEL (old_jump); + new_jump = emit_jump_insn (gen_jump (old_label)); + JUMP_LABEL (new_jump) = old_label; + + last_bb = EXIT_BLOCK_PTR->prev_bb; + new_bb = create_basic_block (new_label, new_jump, last_bb); + new_bb->aux = last_bb->aux; + last_bb->aux = new_bb; + + emit_barrier_after_bb (new_bb); + + /* Make sure new bb is in same partition as source + of conditional branch. */ + BB_COPY_PARTITION (new_bb, cur_bb); + } + + /* Make old jump branch to new bb. */ + + redirect_jump (old_jump, new_label, 0); + + /* Remove crossing_edge as predecessor of 'dest'. */ + + dest = crossing_edge->dest; + + redirect_edge_succ (crossing_edge, new_bb); + + /* Make a new edge from new_bb to old dest; new edge + will be a successor for new_bb and a predecessor + for 'dest'. */ + + if (EDGE_COUNT (new_bb->succs) == 0) + new_edge = make_edge (new_bb, dest, 0); + else + new_edge = EDGE_SUCC (new_bb, 0); + + crossing_edge->flags &= ~EDGE_CROSSING; + new_edge->flags |= EDGE_CROSSING; + } + } + } +} + +/* Find any unconditional branches that cross between hot and cold + sections. Convert them into indirect jumps instead. */ + +static void +fix_crossing_unconditional_branches (void) +{ + basic_block cur_bb; + rtx last_insn; + rtx label; + rtx label_addr; + rtx indirect_jump_sequence; + rtx jump_insn = NULL_RTX; + rtx new_reg; + rtx cur_insn; + edge succ; + + FOR_EACH_BB (cur_bb) + { + last_insn = BB_END (cur_bb); + + if (EDGE_COUNT (cur_bb->succs) < 1) + continue; + + succ = EDGE_SUCC (cur_bb, 0); + + /* Check to see if bb ends in a crossing (unconditional) jump. At + this point, no crossing jumps should be conditional. */ + + if (JUMP_P (last_insn) + && (succ->flags & EDGE_CROSSING)) + { + rtx label2, table; + + gcc_assert (!any_condjump_p (last_insn)); + + /* Make sure the jump is not already an indirect or table jump. */ + + if (!computed_jump_p (last_insn) + && !tablejump_p (last_insn, &label2, &table)) + { + /* We have found a "crossing" unconditional branch. Now + we must convert it to an indirect jump. First create + reference of label, as target for jump. */ + + label = JUMP_LABEL (last_insn); + label_addr = gen_rtx_LABEL_REF (Pmode, label); + LABEL_NUSES (label) += 1; + + /* Get a register to use for the indirect jump. */ + + new_reg = gen_reg_rtx (Pmode); + + /* Generate indirect the jump sequence. */ + + start_sequence (); + emit_move_insn (new_reg, label_addr); + emit_indirect_jump (new_reg); + indirect_jump_sequence = get_insns (); + end_sequence (); + + /* Make sure every instruction in the new jump sequence has + its basic block set to be cur_bb. */ + + for (cur_insn = indirect_jump_sequence; cur_insn; + cur_insn = NEXT_INSN (cur_insn)) + { + if (!BARRIER_P (cur_insn)) + BLOCK_FOR_INSN (cur_insn) = cur_bb; + if (JUMP_P (cur_insn)) + jump_insn = cur_insn; + } + + /* Insert the new (indirect) jump sequence immediately before + the unconditional jump, then delete the unconditional jump. */ + + emit_insn_before (indirect_jump_sequence, last_insn); + delete_insn (last_insn); + + /* Make BB_END for cur_bb be the jump instruction (NOT the + barrier instruction at the end of the sequence...). */ + + BB_END (cur_bb) = jump_insn; + } + } + } +} + +/* Add REG_CROSSING_JUMP note to all crossing jump insns. */ + +static void +add_reg_crossing_jump_notes (void) +{ + basic_block bb; + edge e; + edge_iterator ei; + + FOR_EACH_BB (bb) + FOR_EACH_EDGE (e, ei, bb->succs) + if ((e->flags & EDGE_CROSSING) + && JUMP_P (BB_END (e->src))) + add_reg_note (BB_END (e->src), REG_CROSSING_JUMP, NULL_RTX); +} + +/* Verify, in the basic block chain, that there is at most one switch + between hot/cold partitions. This is modelled on + rtl_verify_flow_info_1, but it cannot go inside that function + because this condition will not be true until after + reorder_basic_blocks is called. */ + +static void +verify_hot_cold_block_grouping (void) +{ + basic_block bb; + int err = 0; + bool switched_sections = false; + int current_partition = 0; + + FOR_EACH_BB (bb) + { + if (!current_partition) + current_partition = BB_PARTITION (bb); + if (BB_PARTITION (bb) != current_partition) + { + if (switched_sections) + { + error ("multiple hot/cold transitions found (bb %i)", + bb->index); + err = 1; + } + else + { + switched_sections = true; + current_partition = BB_PARTITION (bb); + } + } + } + + gcc_assert(!err); +} + +/* Reorder basic blocks. The main entry point to this file. FLAGS is + the set of flags to pass to cfg_layout_initialize(). */ void reorder_basic_blocks (void) @@ -1072,16 +1910,11 @@ reorder_basic_blocks (void) int i; struct trace *traces; - if (n_basic_blocks <= 1) - return; + gcc_assert (current_ir_type () == IR_RTL_CFGLAYOUT); - if (targetm.cannot_modify_jumps_p ()) + if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) return; - timevar_push (TV_REORDER_BLOCKS); - - cfg_layout_initialize (); - set_edge_can_fallthru_flag (); mark_dfs_back_edges (); @@ -1092,26 +1925,467 @@ reorder_basic_blocks (void) /* We need to know some information for each basic block. */ array_size = GET_ARRAY_SIZE (last_basic_block); - bbd = xmalloc (array_size * sizeof (bbro_basic_block_data)); + bbd = XNEWVEC (bbro_basic_block_data, array_size); for (i = 0; i < array_size; i++) { bbd[i].start_of_trace = -1; + bbd[i].in_trace = -1; bbd[i].end_of_trace = -1; bbd[i].heap = NULL; bbd[i].node = NULL; } - traces = xmalloc (n_basic_blocks * sizeof (struct trace)); + traces = XNEWVEC (struct trace, n_basic_blocks); n_traces = 0; find_traces (&n_traces, traces); connect_traces (n_traces, traces); FREE (traces); FREE (bbd); + relink_block_chain (/*stay_in_cfglayout_mode=*/true); + if (dump_file) - dump_flow_info (dump_file); + dump_flow_info (dump_file, dump_flags); + + if (flag_reorder_blocks_and_partition) + verify_hot_cold_block_grouping (); +} + +/* Determine which partition the first basic block in the function + belongs to, then find the first basic block in the current function + that belongs to a different section, and insert a + NOTE_INSN_SWITCH_TEXT_SECTIONS note immediately before it in the + instruction stream. When writing out the assembly code, + encountering this note will make the compiler switch between the + hot and cold text sections. */ + +static void +insert_section_boundary_note (void) +{ + basic_block bb; + rtx new_note; + int first_partition = 0; + + if (!flag_reorder_blocks_and_partition) + return; + + FOR_EACH_BB (bb) + { + if (!first_partition) + first_partition = BB_PARTITION (bb); + if (BB_PARTITION (bb) != first_partition) + { + new_note = emit_note_before (NOTE_INSN_SWITCH_TEXT_SECTIONS, + BB_HEAD (bb)); + /* ??? This kind of note always lives between basic blocks, + but add_insn_before will set BLOCK_FOR_INSN anyway. */ + BLOCK_FOR_INSN (new_note) = NULL; + break; + } + } +} + +/* Duplicate the blocks containing computed gotos. This basically unfactors + computed gotos that were factored early on in the compilation process to + speed up edge based data flow. We used to not unfactoring them again, + which can seriously pessimize code with many computed jumps in the source + code, such as interpreters. See e.g. PR15242. */ + +static bool +gate_duplicate_computed_gotos (void) +{ + if (targetm.cannot_modify_jumps_p ()) + return false; + return (optimize > 0 + && flag_expensive_optimizations + && ! optimize_function_for_size_p (cfun)); +} + + +static unsigned int +duplicate_computed_gotos (void) +{ + basic_block bb, new_bb; + bitmap candidates; + int max_size; + + if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) + return 0; + + cfg_layout_initialize (0); + + /* We are estimating the length of uncond jump insn only once + since the code for getting the insn length always returns + the minimal length now. */ + if (uncond_jump_length == 0) + uncond_jump_length = get_uncond_jump_length (); + + max_size = uncond_jump_length * PARAM_VALUE (PARAM_MAX_GOTO_DUPLICATION_INSNS); + candidates = BITMAP_ALLOC (NULL); + + /* Look for blocks that end in a computed jump, and see if such blocks + are suitable for unfactoring. If a block is a candidate for unfactoring, + mark it in the candidates. */ + FOR_EACH_BB (bb) + { + rtx insn; + edge e; + edge_iterator ei; + int size, all_flags; + + /* Build the reorder chain for the original order of blocks. */ + if (bb->next_bb != EXIT_BLOCK_PTR) + bb->aux = bb->next_bb; + + /* Obviously the block has to end in a computed jump. */ + if (!computed_jump_p (BB_END (bb))) + continue; + + /* Only consider blocks that can be duplicated. */ + if (find_reg_note (BB_END (bb), REG_CROSSING_JUMP, NULL_RTX) + || !can_duplicate_block_p (bb)) + continue; + + /* Make sure that the block is small enough. */ + size = 0; + FOR_BB_INSNS (bb, insn) + if (INSN_P (insn)) + { + size += get_attr_min_length (insn); + if (size > max_size) + break; + } + if (size > max_size) + continue; + + /* Final check: there must not be any incoming abnormal edges. */ + all_flags = 0; + FOR_EACH_EDGE (e, ei, bb->preds) + all_flags |= e->flags; + if (all_flags & EDGE_COMPLEX) + continue; + + bitmap_set_bit (candidates, bb->index); + } + + /* Nothing to do if there is no computed jump here. */ + if (bitmap_empty_p (candidates)) + goto done; + + /* Duplicate computed gotos. */ + FOR_EACH_BB (bb) + { + if (bb->il.rtl->visited) + continue; + + bb->il.rtl->visited = 1; + + /* BB must have one outgoing edge. That edge must not lead to + the exit block or the next block. + The destination must have more than one predecessor. */ + if (!single_succ_p (bb) + || single_succ (bb) == EXIT_BLOCK_PTR + || single_succ (bb) == bb->next_bb + || single_pred_p (single_succ (bb))) + continue; + + /* The successor block has to be a duplication candidate. */ + if (!bitmap_bit_p (candidates, single_succ (bb)->index)) + continue; + + new_bb = duplicate_block (single_succ (bb), single_succ_edge (bb), bb); + new_bb->aux = bb->aux; + bb->aux = new_bb; + new_bb->il.rtl->visited = 1; + } + +done: + cfg_layout_finalize (); + + BITMAP_FREE (candidates); + return 0; +} + +struct rtl_opt_pass pass_duplicate_computed_gotos = +{ + { + RTL_PASS, + "compgotos", /* name */ + gate_duplicate_computed_gotos, /* gate */ + duplicate_computed_gotos, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_REORDER_BLOCKS, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_verify_rtl_sharing,/* todo_flags_finish */ + } +}; + + +/* This function is the main 'entrance' for the optimization that + partitions hot and cold basic blocks into separate sections of the + .o file (to improve performance and cache locality). Ideally it + would be called after all optimizations that rearrange the CFG have + been called. However part of this optimization may introduce new + register usage, so it must be called before register allocation has + occurred. This means that this optimization is actually called + well before the optimization that reorders basic blocks (see + function above). + + This optimization checks the feedback information to determine + which basic blocks are hot/cold, updates flags on the basic blocks + to indicate which section they belong in. This information is + later used for writing out sections in the .o file. Because hot + and cold sections can be arbitrarily large (within the bounds of + memory), far beyond the size of a single function, it is necessary + to fix up all edges that cross section boundaries, to make sure the + instructions used can actually span the required distance. The + fixes are described below. + + Fall-through edges must be changed into jumps; it is not safe or + legal to fall through across a section boundary. Whenever a + fall-through edge crossing a section boundary is encountered, a new + basic block is inserted (in the same section as the fall-through + source), and the fall through edge is redirected to the new basic + block. The new basic block contains an unconditional jump to the + original fall-through target. (If the unconditional jump is + insufficient to cross section boundaries, that is dealt with a + little later, see below). + + In order to deal with architectures that have short conditional + branches (which cannot span all of memory) we take any conditional + jump that attempts to cross a section boundary and add a level of + indirection: it becomes a conditional jump to a new basic block, in + the same section. The new basic block contains an unconditional + jump to the original target, in the other section. + + For those architectures whose unconditional branch is also + incapable of reaching all of memory, those unconditional jumps are + converted into indirect jumps, through a register. + + IMPORTANT NOTE: This optimization causes some messy interactions + with the cfg cleanup optimizations; those optimizations want to + merge blocks wherever possible, and to collapse indirect jump + sequences (change "A jumps to B jumps to C" directly into "A jumps + to C"). Those optimizations can undo the jump fixes that + partitioning is required to make (see above), in order to ensure + that jumps attempting to cross section boundaries are really able + to cover whatever distance the jump requires (on many architectures + conditional or unconditional jumps are not able to reach all of + memory). Therefore tests have to be inserted into each such + optimization to make sure that it does not undo stuff necessary to + cross partition boundaries. This would be much less of a problem + if we could perform this optimization later in the compilation, but + unfortunately the fact that we may need to create indirect jumps + (through registers) requires that this optimization be performed + before register allocation. + + Hot and cold basic blocks are partitioned and put in separate + sections of the .o file, to reduce paging and improve cache + performance (hopefully). This can result in bits of code from the + same function being widely separated in the .o file. However this + is not obvious to the current bb structure. Therefore we must take + care to ensure that: 1). There are no fall_thru edges that cross + between sections; 2). For those architectures which have "short" + conditional branches, all conditional branches that attempt to + cross between sections are converted to unconditional branches; + and, 3). For those architectures which have "short" unconditional + branches, all unconditional branches that attempt to cross between + sections are converted to indirect jumps. + + The code for fixing up fall_thru edges that cross between hot and + cold basic blocks does so by creating new basic blocks containing + unconditional branches to the appropriate label in the "other" + section. The new basic block is then put in the same (hot or cold) + section as the original conditional branch, and the fall_thru edge + is modified to fall into the new basic block instead. By adding + this level of indirection we end up with only unconditional branches + crossing between hot and cold sections. + + Conditional branches are dealt with by adding a level of indirection. + A new basic block is added in the same (hot/cold) section as the + conditional branch, and the conditional branch is retargeted to the + new basic block. The new basic block contains an unconditional branch + to the original target of the conditional branch (in the other section). + + Unconditional branches are dealt with by converting them into + indirect jumps. */ + +static unsigned +partition_hot_cold_basic_blocks (void) +{ + VEC(edge, heap) *crossing_edges; + + if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) + return 0; + + df_set_flags (DF_DEFER_INSN_RESCAN); + + crossing_edges = find_rarely_executed_basic_blocks_and_crossing_edges (); + if (crossing_edges == NULL) + return 0; + + /* Make sure the source of any crossing edge ends in a jump and the + destination of any crossing edge has a label. */ + add_labels_and_missing_jumps (crossing_edges); + + /* Convert all crossing fall_thru edges to non-crossing fall + thrus to unconditional jumps (that jump to the original fall + thru dest). */ + fix_up_fall_thru_edges (); + + /* If the architecture does not have conditional branches that can + span all of memory, convert crossing conditional branches into + crossing unconditional branches. */ + if (!HAS_LONG_COND_BRANCH) + fix_crossing_conditional_branches (); + + /* If the architecture does not have unconditional branches that + can span all of memory, convert crossing unconditional branches + into indirect jumps. Since adding an indirect jump also adds + a new register usage, update the register usage information as + well. */ + if (!HAS_LONG_UNCOND_BRANCH) + fix_crossing_unconditional_branches (); + + add_reg_crossing_jump_notes (); + + /* Clear bb->aux fields that the above routines were using. */ + clear_aux_for_blocks (); + + VEC_free (edge, heap, crossing_edges); + + /* ??? FIXME: DF generates the bb info for a block immediately. + And by immediately, I mean *during* creation of the block. + + #0 df_bb_refs_collect + #1 in df_bb_refs_record + #2 in create_basic_block_structure + + Which means that the bb_has_eh_pred test in df_bb_refs_collect + will *always* fail, because no edges can have been added to the + block yet. Which of course means we don't add the right + artificial refs, which means we fail df_verify (much) later. + + Cleanest solution would seem to make DF_DEFER_INSN_RESCAN imply + that we also shouldn't grab data from the new blocks those new + insns are in either. In this way one can create the block, link + it up properly, and have everything Just Work later, when deferred + insns are processed. + + In the meantime, we have no other option but to throw away all + of the DF data and recompute it all. */ + if (cfun->eh->lp_array) + { + df_finish_pass (true); + df_scan_alloc (NULL); + df_scan_blocks (); + /* Not all post-landing pads use all of the EH_RETURN_DATA_REGNO + data. We blindly generated all of them when creating the new + landing pad. Delete those assignments we don't use. */ + df_set_flags (DF_LR_RUN_DCE); + df_analyze (); + } + return TODO_verify_flow | TODO_verify_rtl_sharing; +} + +static bool +gate_handle_reorder_blocks (void) +{ + if (targetm.cannot_modify_jumps_p ()) + return false; + /* Don't reorder blocks when optimizing for size because extra jump insns may + be created; also barrier may create extra padding. + + More correctly we should have a block reordering mode that tried to + minimize the combined size of all the jumps. This would more or less + automatically remove extra jumps, but would also try to use more short + jumps instead of long jumps. */ + if (!optimize_function_for_speed_p (cfun)) + return false; + return (optimize > 0 + && (flag_reorder_blocks || flag_reorder_blocks_and_partition)); +} + + +/* Reorder basic blocks. */ +static unsigned int +rest_of_handle_reorder_blocks (void) +{ + basic_block bb; + + /* Last attempt to optimize CFG, as scheduling, peepholing and insn + splitting possibly introduced more crossjumping opportunities. */ + cfg_layout_initialize (CLEANUP_EXPENSIVE); + + reorder_basic_blocks (); + cleanup_cfg (CLEANUP_EXPENSIVE); + + FOR_EACH_BB (bb) + if (bb->next_bb != EXIT_BLOCK_PTR) + bb->aux = bb->next_bb; cfg_layout_finalize (); - timevar_pop (TV_REORDER_BLOCKS); + /* Add NOTE_INSN_SWITCH_TEXT_SECTIONS notes. */ + insert_section_boundary_note (); + return 0; +} + +struct rtl_opt_pass pass_reorder_blocks = +{ + { + RTL_PASS, + "bbro", /* name */ + gate_handle_reorder_blocks, /* gate */ + rest_of_handle_reorder_blocks, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_REORDER_BLOCKS, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_verify_rtl_sharing, /* todo_flags_finish */ + } +}; + +static bool +gate_handle_partition_blocks (void) +{ + /* The optimization to partition hot/cold basic blocks into separate + sections of the .o file does not work well with linkonce or with + user defined section attributes. Don't call it if either case + arises. */ + return (flag_reorder_blocks_and_partition + && optimize + /* See gate_handle_reorder_blocks. We should not partition if + we are going to omit the reordering. */ + && optimize_function_for_speed_p (cfun) + && !DECL_ONE_ONLY (current_function_decl) + && !user_defined_section_attribute); } + +struct rtl_opt_pass pass_partition_blocks = +{ + { + RTL_PASS, + "bbpart", /* name */ + gate_handle_partition_blocks, /* gate */ + partition_hot_cold_basic_blocks, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_REORDER_BLOCKS, /* tv_id */ + PROP_cfglayout, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + 0 /* todo_flags_finish */ + } +};