X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fbb-reorder.c;h=9428ef3b92302abf0f8e994a1489161693503a68;hb=f1225f6f0f9b7acb3a64314f2113807ebeea5abf;hp=f89900d470b12e2e95b1771b1d8bccc7726c0cc1;hpb=d5ade7f449e69d05f535d632bf7f3410b1eb3e7f;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c index f89900d470b..9428ef3b923 100644 --- a/gcc/bb-reorder.c +++ b/gcc/bb-reorder.c @@ -1,5 +1,6 @@ /* Basic block reordering routines for the GNU compiler. - Copyright (C) 2000, 2002, 2003 Free Software Foundation, Inc. + Copyright (C) 2000, 2002, 2003, 2004, 2005, 2006, 2007 + Free Software Foundation, Inc. This file is part of GCC. @@ -15,8 +16,8 @@ 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. */ + Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA + 02110-1301, USA. */ /* This (greedy) algorithm constructs traces in several rounds. The construction starts from "seeds". The seed for the first round @@ -70,21 +71,44 @@ #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 "toplev.h" +#include "tree-pass.h" + +#ifndef HAVE_conditional_execution +#define HAVE_conditional_execution 0 +#endif + +/* 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 -/* The number of rounds. */ -#define N_ROUNDS 4 /* 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. */ @@ -102,6 +126,9 @@ 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; @@ -120,8 +147,7 @@ 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 @@ -137,43 +163,84 @@ 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 PARAMS ((int *, struct trace *)); -static basic_block rotate_loop PARAMS ((edge, struct trace *, int)); -static void mark_bb_visited PARAMS ((basic_block, int)); -static void find_traces_1_round PARAMS ((int, int, gcov_type, - struct trace *, int *, int, - fibheap_t *)); -static basic_block copy_bb PARAMS ((basic_block, edge, - basic_block, int)); -static fibheapkey_t bb_to_key PARAMS ((basic_block)); -static bool better_edge_p PARAMS ((basic_block, edge, int, int, - int, int)); -static void connect_traces PARAMS ((int, struct trace *)); -static bool copy_bb_p PARAMS ((basic_block, int)); -static int get_uncond_jump_length PARAMS ((void)); +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); +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, 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 push_to_next_round_p (basic_block, int, int, int, gcov_type); +static void find_rarely_executed_basic_blocks_and_crossing_edges (edge *, + int *, + int *); +static void add_labels_and_missing_jumps (edge *, int); +static void add_reg_crossing_jump_notes (void); +static void fix_up_fall_thru_edges (void); +static void fix_edges_for_rarely_executed_code (edge *, int); +static void fix_crossing_conditional_branches (void); +static void fix_crossing_unconditional_branches (void); +/* 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 (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. */ static void -find_traces (n_traces, traces) - int *n_traces; - struct trace *traces; +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), @@ -185,12 +252,12 @@ find_traces (n_traces, traces) } /* Find the traces. */ - for (i = 0; i < N_ROUNDS; i++) + for (i = 0; i < number_of_rounds; i++) { gcov_type count_threshold; - if (rtl_dump_file) - fprintf (rtl_dump_file, "STC - round %d\n", i + 1); + if (dump_file) + fprintf (dump_file, "STC - round %d\n", i + 1); if (max_entry_count < INT_MAX / 1000) count_threshold = max_entry_count * exec_threshold[i] / 1000; @@ -199,22 +266,23 @@ find_traces (n_traces, 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); - if (rtl_dump_file) + if (dump_file) { for (i = 0; i < *n_traces; i++) { basic_block bb; - fprintf (rtl_dump_file, "Trace %d (round %d): ", i + 1, + fprintf (dump_file, "Trace %d (round %d): ", i + 1, traces[i].round + 1); - for (bb = traces[i].first; bb != traces[i].last; bb = RBI (bb)->next) - fprintf (rtl_dump_file, "%d [%d] ", bb->index, bb->frequency); - fprintf (rtl_dump_file, "%d [%d]\n", bb->index, bb->frequency); + for (bb = traces[i].first; bb != traces[i].last; bb = bb->aux) + fprintf (dump_file, "%d [%d] ", bb->index, bb->frequency); + fprintf (dump_file, "%d [%d]\n", bb->index, bb->frequency); } - fflush (rtl_dump_file); + fflush (dump_file); } } @@ -222,10 +290,7 @@ find_traces (n_traces, traces) (with sequential number TRACE_N). */ static basic_block -rotate_loop (back_edge, trace, trace_n) - edge back_edge; - struct trace *trace; - int trace_n; +rotate_loop (edge back_edge, struct trace *trace, int trace_n) { basic_block bb; @@ -243,16 +308,18 @@ rotate_loop (back_edge, trace, 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 - && RBI (e->dest)->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 (!RBI (e->dest)->visited + if (!e->dest->il.rtl->visited || bbd[e->dest->index].start_of_trace >= 0) { /* The current edge E is also preferred. */ @@ -268,7 +335,7 @@ rotate_loop (back_edge, trace, trace_n) } else { - if (!RBI (e->dest)->visited + if (!e->dest->il.rtl->visited || bbd[e->dest->index].start_of_trace >= 0) { /* The current edge E is preferred. */ @@ -291,7 +358,7 @@ rotate_loop (back_edge, trace, trace_n) } } } - bb = RBI (bb)->next; + bb = bb->aux; } while (bb != back_edge->dest); @@ -301,29 +368,29 @@ rotate_loop (back_edge, trace, trace_n) the trace. */ if (back_edge->dest == trace->first) { - trace->first = RBI (best_bb)->next; + trace->first = best_bb->aux; } else { basic_block prev_bb; for (prev_bb = trace->first; - RBI (prev_bb)->next != back_edge->dest; - prev_bb = RBI (prev_bb)->next) + prev_bb->aux != back_edge->dest; + prev_bb = prev_bb->aux) ; - RBI (prev_bb)->next = RBI (best_bb)->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 (header->end) && 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); } } } @@ -332,18 +399,16 @@ rotate_loop (back_edge, trace, trace_n) /* We have not found suitable loop tail so do no rotation. */ best_bb = back_edge->src; } - RBI (best_bb)->next = NULL; + best_bb->aux = NULL; return best_bb; } /* This function marks BB that it was visited in trace number TRACE. */ static void -mark_bb_visited (bb, trace) - basic_block bb; - int trace; +mark_bb_visited (basic_block bb, int trace) { - RBI (bb)->visited = trace; + bb->il.rtl->visited = trace; if (bbd[bb->index].heap) { fibheap_delete_node (bbd[bb->index].heap, bbd[bb->index].node); @@ -361,15 +426,9 @@ mark_bb_visited (bb, trace) *HEAP and stores starting points for the next round into new *HEAP. */ static void -find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, - heap) - int branch_th; - int exec_th; - gcov_type count_th; - struct trace *traces; - int *n_traces; - int round; - fibheap_t *heap; +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, int number_of_rounds) { /* Heap for discarded basic blocks which are possible starting points for the next round. */ @@ -381,24 +440,29 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, struct trace *trace; edge best_edge, e; fibheapkey_t key; + edge_iterator ei; bb = fibheap_extract_min (*heap); bbd[bb->index].heap = NULL; bbd[bb->index].node = NULL; - if (rtl_dump_file) - fprintf (rtl_dump_file, "Getting bb %d\n", bb->index); + 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. 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 the BB's frequency is too low send BB to the next round. */ - if (bb->frequency < exec_th || bb->count < count_th - || ((round < N_ROUNDS - 1) && probably_never_executed_bb_p (bb))) + 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; bbd[bb->index].node = fibheap_insert (new_heap, key, bb); - if (rtl_dump_file) - fprintf (rtl_dump_file, + if (dump_file) + fprintf (dump_file, " Possible start point of next round: %d (key: %d)\n", bb->index, key); continue; @@ -408,11 +472,13 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, 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; @@ -422,33 +488,55 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, mark_bb_visited (bb, *n_traces); trace->length++; - if (rtl_dump_file) - fprintf (rtl_dump_file, "Basic block %d was visited in trace %d\n", + if (dump_file) + 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) { - if (e->flags & EDGE_FAKE) - abort (); + gcc_assert (!(e->flags & EDGE_FAKE)); if (e->dest == EXIT_BLOCK_PTR) continue; - if (RBI (e->dest)->visited - && RBI (e->dest)->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; @@ -456,19 +544,19 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, } } - /* If the best destination has multiple precessesors, and can be + /* 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 - || RBI (e->dest)->visited) + || e->dest->il.rtl->visited) continue; key = bb_to_key (e->dest); @@ -478,9 +566,9 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, /* E->DEST is already in some heap. */ if (key != bbd[e->dest->index].node->key) { - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, + fprintf (dump_file, "Changing key for bb %d from %ld to %ld.\n", e->dest->index, (long) bbd[e->dest->index].node->key, @@ -502,7 +590,13 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, || 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; } @@ -510,9 +604,9 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, bbd[e->dest->index].node = fibheap_insert (which_heap, key, e->dest); - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, + fprintf (dump_file, " Possible start of %s round: %d (key: %ld)\n", (which_heap == new_heap) ? "next" : "this", e->dest->index, (long) key); @@ -523,7 +617,7 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, if (best_edge) /* Suitable successor was found. */ { - if (RBI (best_edge->dest)->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) @@ -537,13 +631,15 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, if (best_edge->dest != ENTRY_BLOCK_PTR->next_bb) { - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, + fprintf (dump_file, "Rotating loop %d - %d\n", best_edge->dest->index, bb->index); } - RBI (bb)->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); } } @@ -551,19 +647,12 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, { /* 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_size)) { bb = copy_bb (best_edge->dest, best_edge, bb, *n_traces); + trace->length++; } } } @@ -594,27 +683,29 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, */ - 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) - && !RBI (e->dest)->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; - if (rtl_dump_file) - fprintf (rtl_dump_file, "Selecting BB %d\n", + if (dump_file) + fprintf (dump_file, "Selecting BB %d\n", best_edge->dest->index); break; } - RBI (bb)->next = best_edge->dest; + bb->aux = best_edge->dest; + bbd[best_edge->dest->index].in_trace = (*n_traces) - 1; bb = best_edge->dest; } } @@ -627,10 +718,10 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, /* 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 - || RBI (e->dest)->visited) + || e->dest->il.rtl->visited) continue; if (bbd[e->dest->index].heap) @@ -638,9 +729,9 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, key = bb_to_key (e->dest); if (key != bbd[e->dest->index].node->key) { - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, + fprintf (dump_file, "Changing key for bb %d from %ld to %ld.\n", e->dest->index, (long) bbd[e->dest->index].node->key, key); @@ -664,26 +755,23 @@ find_traces_1_round (branch_th, exec_th, count_th, traces, n_traces, round, (TRACE is a number of trace which OLD_BB is duplicated to). */ static basic_block -copy_bb (old_bb, e, bb, trace) - basic_block old_bb; - edge e; - basic_block bb; - int trace; +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 (RBI (e->dest)->visited) - abort (); - if (rtl_dump_file) - fprintf (rtl_dump_file, + 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); - RBI (new_bb)->visited = trace; - RBI (new_bb)->next = RBI (bb)->next; - RBI (bb)->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) { @@ -696,40 +784,44 @@ copy_bb (old_bb, e, bb, trace) 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; } array_size = new_size; - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, + fprintf (dump_file, "Growing the dynamic array to %d elements.\n", array_size); } } + bbd[new_bb->index].in_trace = trace; + return new_bb; } /* Compute and return the key (for the heap) of the basic block BB. */ static fibheapkey_t -bb_to_key (bb) - basic_block bb; +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)) @@ -755,13 +847,8 @@ bb_to_key (bb) BEST_PROB; similarly for frequency. */ static bool -better_edge_p (bb, e, prob, freq, best_prob, best_freq) - basic_block bb; - edge e; - int prob; - int freq; - int best_prob; - int best_freq; +better_edge_p (basic_block bb, edge e, int prob, int freq, int best_prob, + int best_freq, edge cur_best_edge) { bool is_better_edge; @@ -792,19 +879,30 @@ better_edge_p (bb, e, prob, freq, best_prob, best_freq) 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; } /* Connect traces in array TRACES, N_TRACES is the count of traces. */ static void -connect_traces (n_traces, traces) - int n_traces; - struct trace *traces; +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; @@ -814,26 +912,53 @@ connect_traces (n_traces, 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; @@ -842,6 +967,7 @@ connect_traces (n_traces, 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 @@ -853,12 +979,13 @@ connect_traces (n_traces, traces) } if (best) { - RBI (best->src)->next = best->dest; + best->src->aux = best->dest; t2 = bbd[best->src->index].end_of_trace; connected[t2] = true; - if (rtl_dump_file) + + if (dump_file) { - fprintf (rtl_dump_file, "Connection: %d %d\n", + fprintf (dump_file, "Connection: %d %d\n", best->src->index, best->dest->index); } } @@ -867,16 +994,17 @@ connect_traces (n_traces, traces) } if (last_trace >= 0) - RBI (traces[last_trace].last)->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; @@ -885,6 +1013,7 @@ connect_traces (n_traces, 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 @@ -897,13 +1026,13 @@ connect_traces (n_traces, traces) if (best) { - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, "Connection: %d %d\n", + fprintf (dump_file, "Connection: %d %d\n", best->src->index, best->dest->index); } t = bbd[best->dest->index].start_of_trace; - RBI (traces[last_trace].last)->next = traces[t].first; + traces[last_trace].last->aux = traces[t].first; connected[t] = true; last_trace = t; } @@ -914,12 +1043,13 @@ connect_traces (n_traces, 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; @@ -935,7 +1065,7 @@ connect_traces (n_traces, 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; @@ -944,6 +1074,7 @@ connect_traces (n_traces, 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 @@ -964,6 +1095,9 @@ connect_traces (n_traces, 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 @@ -974,16 +1108,16 @@ connect_traces (n_traces, traces) { basic_block new_bb; - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, "Connection: %d %d ", + fprintf (dump_file, "Connection: %d %d ", traces[t].last->index, best->dest->index); if (!next_bb) - fputc ('\n', rtl_dump_file); + fputc ('\n', dump_file); else if (next_bb == EXIT_BLOCK_PTR) - fprintf (rtl_dump_file, "exit\n"); + fprintf (dump_file, "exit\n"); else - fprintf (rtl_dump_file, "%d\n", next_bb->index); + fprintf (dump_file, "%d\n", next_bb->index); } new_bb = copy_bb (best->dest, best, traces[t].last, t); @@ -991,7 +1125,7 @@ connect_traces (n_traces, traces) if (next_bb && next_bb != EXIT_BLOCK_PTR) { t = bbd[next_bb->index].start_of_trace; - RBI (traces[last_trace].last)->next = traces[t].first; + traces[last_trace].last->aux = traces[t].first; connected[t] = true; last_trace = t; } @@ -1004,15 +1138,15 @@ connect_traces (n_traces, traces) } } - if (rtl_dump_file) + if (dump_file) { basic_block bb; - fprintf (rtl_dump_file, "Final order:\n"); - for (bb = traces[0].first; bb; bb = RBI (bb)->next) - fprintf (rtl_dump_file, "%d ", bb->index); - fprintf (rtl_dump_file, "\n"); - fflush (rtl_dump_file); + fprintf (dump_file, "Final order:\n"); + for (bb = traces[0].first; bb; bb = bb->aux) + fprintf (dump_file, "%d ", bb->index); + fprintf (dump_file, "\n"); + fflush (dump_file); } FREE (connected); @@ -1022,9 +1156,7 @@ connect_traces (n_traces, traces) when code size is allowed to grow by duplication. */ static bool -copy_bb_p (bb, code_may_grow) - basic_block bb; - int code_may_grow; +copy_bb_p (basic_block bb, int code_may_grow) { int size = 0; int max_size = uncond_jump_length; @@ -1032,27 +1164,30 @@ copy_bb_p (bb, code_may_grow) 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). */ + if (EDGE_COUNT (bb->succs) > 8) return false; if (code_may_grow && maybe_hot_bb_p (bb)) - max_size *= 8; + max_size *= PARAM_VALUE (PARAM_MAX_GROW_COPY_BB_INSNS); - for (insn = bb->head; insn != NEXT_INSN (bb->end); - 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) return true; - if (rtl_dump_file) + if (dump_file) { - fprintf (rtl_dump_file, + fprintf (dump_file, "Block %d can't be copied because its size = %d.\n", bb->index, size); } @@ -1063,7 +1198,7 @@ copy_bb_p (bb, code_may_grow) /* Return the length of unconditional jump instruction. */ static int -get_uncond_jump_length () +get_uncond_jump_length (void) { rtx label, jump; int length; @@ -1071,58 +1206,1097 @@ get_uncond_jump_length () 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. */ +/* 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). */ + +static void +find_rarely_executed_basic_blocks_and_crossing_edges (edge *crossing_edges, + int *n_crossing_edges, + int *max_idx) +{ + basic_block bb; + bool has_hot_blocks = false; + edge e; + int i; + 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); + has_hot_blocks = true; + } + } + + /* Mark every edge that crosses between sections. */ + + i = 0; + FOR_EACH_BB (bb) + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (e->src != ENTRY_BLOCK_PTR + && e->dest != EXIT_BLOCK_PTR + && BB_PARTITION (e->src) != BB_PARTITION (e->dest)) + { + e->flags |= EDGE_CROSSING; + if (i == *max_idx) + { + *max_idx *= 2; + crossing_edges = xrealloc (crossing_edges, + (*max_idx) * sizeof (edge)); + } + crossing_edges[i++] = e; + } + else + e->flags &= ~EDGE_CROSSING; + } + *n_crossing_edges = i; +} + +/* If any destination of a crossing edge does not have a label, add label; + Convert any fall-through crossing edges (for blocks that do not contain + a jump) to unconditional jumps. */ + +static void +add_labels_and_missing_jumps (edge *crossing_edges, int n_crossing_edges) +{ + int i; + basic_block src; + basic_block dest; + rtx label; + rtx barrier; + rtx new_jump; + + for (i=0; i < n_crossing_edges; i++) + { + if (crossing_edges[i]) + { + src = crossing_edges[i]->src; + dest = crossing_edges[i]->dest; + + /* Make sure dest has a label. */ + + if (dest && (dest != EXIT_BLOCK_PTR)) + { + label = block_label (dest); + + /* Make sure source block ends with a jump. */ + + if (src && (src != ENTRY_BLOCK_PTR)) + { + if (!JUMP_P (BB_END (src))) + /* bb just falls through. */ + { + /* make sure there's only one successor */ + gcc_assert (single_succ_p (src)); + + /* Find label in dest block. */ + label = block_label (dest); + + new_jump = emit_jump_insn_after (gen_jump (label), + BB_END (src)); + barrier = emit_barrier_after (new_jump); + JUMP_LABEL (new_jump) = label; + LABEL_NUSES (label) += 1; + src->il.rtl->footer = unlink_insn_chain (barrier, barrier); + /* Mark edge as non-fallthru. */ + crossing_edges[i]->flags &= ~EDGE_FALLTHRU; + } /* end: 'if (GET_CODE ... ' */ + } /* end: 'if (src && src->index...' */ + } /* end: 'if (dest && dest->index...' */ + } /* end: 'if (crossing_edges[i]...' */ + } /* end for loop */ +} + +/* Find any bb's where the fall-through edge is a crossing edge (note that + these bb's must also contain a conditional jump; we've already + dealt with fall-through edges for blocks that didn't have a + conditional jump 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; + rtx barrier; + + 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; + } + + 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 && 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. */ + + 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; + } + + /* Add barrier after new jump */ + + if (new_bb) + { + barrier = emit_barrier_after (BB_END (new_bb)); + new_bb->il.rtl->footer = unlink_insn_chain (barrier, + barrier); + } + else + { + barrier = emit_barrier_after (BB_END (cur_bb)); + cur_bb->il.rtl->footer = unlink_insn_chain (barrier, + barrier); + } + } + } + } + } +} + +/* This function checks the destination blockof 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 last_bb; + basic_block dest; + basic_block prev_bb; + edge succ1; + edge succ2; + edge crossing_edge; + edge new_edge; + rtx old_jump; + rtx set_src; + rtx old_label = NULL_RTX; + rtx new_label; + rtx new_jump; + rtx barrier; + + last_bb = EXIT_BLOCK_PTR->prev_bb; + + 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 + { + /* Create new basic block to be dest for + conditional jump. */ + + new_bb = create_basic_block (NULL, NULL, last_bb); + new_bb->aux = last_bb->aux; + last_bb->aux = new_bb; + prev_bb = last_bb; + last_bb = new_bb; + + /* Update register liveness information. */ + + new_bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); + new_bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); + COPY_REG_SET (new_bb->il.rtl->global_live_at_end, + prev_bb->il.rtl->global_live_at_end); + COPY_REG_SET (new_bb->il.rtl->global_live_at_start, + prev_bb->il.rtl->global_live_at_end); + + /* Put appropriate instructions in new bb. */ + + new_label = gen_label_rtx (); + emit_label_before (new_label, BB_HEAD (new_bb)); + BB_HEAD (new_bb) = new_label; + + if (GET_CODE (old_label) == LABEL_REF) + { + old_label = JUMP_LABEL (old_jump); + new_jump = emit_jump_insn_after (gen_jump + (old_label), + BB_END (new_bb)); + } + else + { + gcc_assert (HAVE_return + && GET_CODE (old_label) == RETURN); + new_jump = emit_jump_insn_after (gen_return (), + BB_END (new_bb)); + } + + barrier = emit_barrier_after (new_jump); + JUMP_LABEL (new_jump) = old_label; + new_bb->il.rtl->footer = unlink_insn_chain (barrier, + barrier); + + /* 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))) + REG_NOTES (BB_END (e->src)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP, + NULL_RTX, + REG_NOTES (BB_END + (e->src))); +} + +/* 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 void +fix_edges_for_rarely_executed_code (edge *crossing_edges, + int n_crossing_edges) +{ + /* 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, n_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 (); + reg_scan (get_insns (), max_reg_num ()); + } + + add_reg_crossing_jump_notes (); +} + +/* 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 () +reorder_basic_blocks (unsigned int flags) { int n_traces; int i; struct trace *traces; - if (n_basic_blocks <= 1) + if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) return; - if ((* targetm.cannot_modify_jumps_p) ()) + if (targetm.cannot_modify_jumps_p ()) return; - cfg_layout_initialize (NULL); + cfg_layout_initialize (flags); set_edge_can_fallthru_flag (); mark_dfs_back_edges (); - /* We are estimating the lenght of uncond jump insn only once since the code - for getting the insn lenght always returns the minimal length now. */ - if (uncond_jump_length == 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 (); /* 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); - if (rtl_dump_file) - dump_flow_info (rtl_dump_file); + if (dump_file) + dump_flow_info (dump_file, dump_flags); + + cfg_layout_finalize (); + 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) + 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)); + 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) +{ + return (optimize > 0 && flag_expensive_optimizations && !optimize_size); +} + + +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; + + if (targetm.cannot_modify_jumps_p ()) + 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 tree_opt_pass pass_duplicate_computed_gotos = +{ + "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_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + + +/* 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. */ + +static void +partition_hot_cold_basic_blocks (void) +{ + basic_block cur_bb; + edge *crossing_edges; + int n_crossing_edges; + int max_edges = 2 * last_basic_block; + + if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1) + return; + + crossing_edges = XCNEWVEC (edge, max_edges); + + cfg_layout_initialize (0); + + FOR_EACH_BB (cur_bb) + if (cur_bb->index >= NUM_FIXED_BLOCKS + && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS) + cur_bb->aux = cur_bb->next_bb; + + find_rarely_executed_basic_blocks_and_crossing_edges (crossing_edges, + &n_crossing_edges, + &max_edges); + + if (n_crossing_edges > 0) + fix_edges_for_rarely_executed_code (crossing_edges, n_crossing_edges); + + free (crossing_edges); + + cfg_layout_finalize (); +} + +static bool +gate_handle_reorder_blocks (void) +{ + return (optimize > 0); } + + +/* Reorder basic blocks. */ +static unsigned int +rest_of_handle_reorder_blocks (void) +{ + bool changed; + unsigned int liveness_flags; + + /* Last attempt to optimize CFG, as scheduling, peepholing and insn + splitting possibly introduced more crossjumping opportunities. */ + liveness_flags = (!HAVE_conditional_execution ? CLEANUP_UPDATE_LIFE : 0); + changed = cleanup_cfg (CLEANUP_EXPENSIVE | liveness_flags); + + if (flag_sched2_use_traces && flag_schedule_insns_after_reload) + { + timevar_push (TV_TRACER); + tracer (liveness_flags); + timevar_pop (TV_TRACER); + } + + if (flag_reorder_blocks || flag_reorder_blocks_and_partition) + reorder_basic_blocks (liveness_flags); + if (flag_reorder_blocks || flag_reorder_blocks_and_partition + || (flag_sched2_use_traces && flag_schedule_insns_after_reload)) + changed |= cleanup_cfg (CLEANUP_EXPENSIVE | liveness_flags); + + /* On conditional execution targets we can not update the life cheaply, so + we deffer the updating to after both cleanups. This may lose some cases + but should not be terribly bad. */ + if (changed && HAVE_conditional_execution) + update_life_info (NULL, UPDATE_LIFE_GLOBAL_RM_NOTES, + PROP_DEATH_NOTES); + + /* Add NOTE_INSN_SWITCH_TEXT_SECTIONS notes. */ + insert_section_boundary_note (); + return 0; +} + +struct tree_opt_pass pass_reorder_blocks = +{ + "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_dump_func, /* todo_flags_finish */ + 'B' /* letter */ +}; + +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 + && !DECL_ONE_ONLY (current_function_decl) + && !user_defined_section_attribute); +} + +/* Partition hot and cold basic blocks. */ +static unsigned int +rest_of_handle_partition_blocks (void) +{ + no_new_pseudos = 0; + partition_hot_cold_basic_blocks (); + allocate_reg_life_data (); + update_life_info (NULL, UPDATE_LIFE_GLOBAL_RM_NOTES, + PROP_LOG_LINKS | PROP_REG_INFO | PROP_DEATH_NOTES); + no_new_pseudos = 1; + return 0; +} + +struct tree_opt_pass pass_partition_blocks = +{ + "bbpart", /* name */ + gate_handle_partition_blocks, /* gate */ + rest_of_handle_partition_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_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + +