X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=blobdiff_plain;f=gcc%2Fcfgloop.c;h=96175a8dbe1b601ef6d1c4c107c7fde94d66c5e6;hp=6fa8b17706ae6a7e40d69c6d6b23a9b05cfb122d;hb=ffc6b5d5b57e2da11b8cff38cc2476ee44c42796;hpb=5f5d4cd12a68a2564978c5cbacbae78e7f9f1559 diff --git a/gcc/cfgloop.c b/gcc/cfgloop.c index 6fa8b17706a..96175a8dbe1 100644 --- a/gcc/cfgloop.c +++ b/gcc/cfgloop.c @@ -1,5 +1,5 @@ /* Natural loop discovery code for GNU compiler. - Copyright (C) 2000, 2001, 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. This file is part of GCC. @@ -24,10 +24,14 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include "tm.h" #include "rtl.h" #include "hard-reg-set.h" +#include "obstack.h" +#include "function.h" #include "basic-block.h" #include "toplev.h" #include "cfgloop.h" #include "flags.h" +#include "tree.h" +#include "tree-flow.h" /* Ratio of frequencies of edges so that one of more latch edges is considered to belong to inner loop with same header. */ @@ -37,13 +41,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #define LATCH_EDGE(E) (*(int *) (E)->aux) static void flow_loops_cfg_dump (const struct loops *, FILE *); -static void flow_loop_entry_edges_find (struct loop *); -static void flow_loop_exit_edges_find (struct loop *); static int flow_loop_nodes_find (basic_block, struct loop *); -static void flow_loop_pre_header_scan (struct loop *); -static basic_block flow_loop_pre_header_find (basic_block); static int flow_loop_level_compute (struct loop *); -static int flow_loops_level_compute (struct loops *); +static void flow_loops_level_compute (struct loops *); static void establish_preds (struct loop *); static void canonicalize_loop_headers (void); static bool glb_enum_p (basic_block, void *); @@ -62,9 +62,10 @@ flow_loops_cfg_dump (const struct loops *loops, FILE *file) FOR_EACH_BB (bb) { edge succ; + edge_iterator ei; fprintf (file, ";; %d succs { ", bb->index); - for (succ = bb->succ; succ; succ = succ->succ_next) + FOR_EACH_EDGE (succ, ei, bb->succs) fprintf (file, "%d ", succ->dest->index); fprintf (file, "}\n"); } @@ -95,8 +96,22 @@ flow_loops_cfg_dump (const struct loops *loops, FILE *file) bool flow_loop_nested_p (const struct loop *outer, const struct loop *loop) { - return loop->depth > outer->depth - && loop->pred[outer->depth] == outer; + return (loop->depth > outer->depth + && loop->pred[outer->depth] == outer); +} + +/* Returns the loop such that LOOP is nested DEPTH (indexed from zero) + loops within LOOP. */ + +struct loop * +superloop_at_depth (struct loop *loop, unsigned depth) +{ + gcc_assert (depth <= (unsigned) loop->depth); + + if (depth == (unsigned) loop->depth) + return loop; + + return loop->pred[depth]; } /* Dump the loop information specified by LOOP to the stream FILE @@ -116,27 +131,18 @@ flow_loop_dump (const struct loop *loop, FILE *file, fprintf (file, ";;\n;; Loop %d:%s\n", loop->num, loop->invalid ? " invalid" : ""); - fprintf (file, ";; header %d, latch %d, pre-header %d\n", - loop->header->index, loop->latch->index, - loop->pre_header ? loop->pre_header->index : -1); + fprintf (file, ";; header %d, latch %d\n", + loop->header->index, loop->latch->index); fprintf (file, ";; depth %d, level %d, outer %ld\n", loop->depth, loop->level, (long) (loop->outer ? loop->outer->num : -1)); - if (loop->pre_header_edges) - flow_edge_list_print (";; pre-header edges", loop->pre_header_edges, - loop->num_pre_header_edges, file); - - flow_edge_list_print (";; entry edges", loop->entry_edges, - loop->num_entries, file); fprintf (file, ";; nodes:"); bbs = get_loop_body (loop); for (i = 0; i < loop->num_nodes; i++) fprintf (file, " %d", bbs[i]->index); free (bbs); fprintf (file, "\n"); - flow_edge_list_print (";; exit edges", loop->exit_edges, - loop->num_exits, file); if (loop_dump_aux) loop_dump_aux (loop, file, verbose); @@ -155,8 +161,7 @@ flow_loops_dump (const struct loops *loops, FILE *file, void (*loop_dump_aux) (c if (! num_loops || ! file) return; - fprintf (file, ";; %d loops found, %d levels\n", - num_loops, loops->levels); + fprintf (file, ";; %d loops found\n", num_loops); for (i = 0; i < num_loops; i++) { @@ -176,12 +181,6 @@ flow_loops_dump (const struct loops *loops, FILE *file, void (*loop_dump_aux) (c void flow_loop_free (struct loop *loop) { - if (loop->pre_header_edges) - free (loop->pre_header_edges); - if (loop->entry_edges) - free (loop->entry_edges); - if (loop->exit_edges) - free (loop->exit_edges); if (loop->pred) free (loop->pred); free (loop); @@ -196,8 +195,7 @@ flow_loops_free (struct loops *loops) { unsigned i; - if (! loops->num) - abort (); + gcc_assert (loops->num); /* Free the loop descriptors. */ for (i = 0; i < loops->num; i++) @@ -221,90 +219,6 @@ flow_loops_free (struct loops *loops) } } -/* Find the entry edges into the LOOP. */ - -static void -flow_loop_entry_edges_find (struct loop *loop) -{ - edge e; - int num_entries; - - num_entries = 0; - for (e = loop->header->pred; e; e = e->pred_next) - { - if (flow_loop_outside_edge_p (loop, e)) - num_entries++; - } - - if (! num_entries) - abort (); - - loop->entry_edges = xmalloc (num_entries * sizeof (edge *)); - - num_entries = 0; - for (e = loop->header->pred; e; e = e->pred_next) - { - if (flow_loop_outside_edge_p (loop, e)) - loop->entry_edges[num_entries++] = e; - } - - loop->num_entries = num_entries; -} - -/* Find the exit edges from the LOOP. */ - -static void -flow_loop_exit_edges_find (struct loop *loop) -{ - edge e; - basic_block node, *bbs; - unsigned num_exits, i; - - loop->exit_edges = NULL; - loop->num_exits = 0; - - /* Check all nodes within the loop to see if there are any - successors not in the loop. Note that a node may have multiple - exiting edges. */ - num_exits = 0; - bbs = get_loop_body (loop); - for (i = 0; i < loop->num_nodes; i++) - { - node = bbs[i]; - for (e = node->succ; e; e = e->succ_next) - { - basic_block dest = e->dest; - - if (!flow_bb_inside_loop_p (loop, dest)) - num_exits++; - } - } - - if (! num_exits) - { - free (bbs); - return; - } - - loop->exit_edges = xmalloc (num_exits * sizeof (edge *)); - - /* Store all exiting edges into an array. */ - num_exits = 0; - for (i = 0; i < loop->num_nodes; i++) - { - node = bbs[i]; - for (e = node->succ; e; e = e->succ_next) - { - basic_block dest = e->dest; - - if (!flow_bb_inside_loop_p (loop, dest)) - loop->exit_edges[num_exits++] = e; - } - } - free (bbs); - loop->num_exits = num_exits; -} - /* Find the nodes contained within the LOOP with header HEADER. Return the number of nodes within the loop. */ @@ -331,10 +245,11 @@ flow_loop_nodes_find (basic_block header, struct loop *loop) { basic_block node; edge e; + edge_iterator ei; node = stack[--sp]; - for (e = node->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, node->preds) { basic_block ancestor = e->src; @@ -353,73 +268,62 @@ flow_loop_nodes_find (basic_block header, struct loop *loop) return num_nodes; } -/* Find the root node of the loop pre-header extended basic block and - the edges along the trace from the root node to the loop header. */ - -static void -flow_loop_pre_header_scan (struct loop *loop) -{ - int num; - basic_block ebb; - edge e; - - loop->num_pre_header_edges = 0; - if (loop->num_entries != 1) - return; - - ebb = loop->entry_edges[0]->src; - if (ebb == ENTRY_BLOCK_PTR) - return; - - /* Count number of edges along trace from loop header to - root of pre-header extended basic block. Usually this is - only one or two edges. */ - for (num = 1; ebb->pred->src != ENTRY_BLOCK_PTR && ! ebb->pred->pred_next; - num++) - ebb = ebb->pred->src; - - loop->pre_header_edges = xmalloc (num * sizeof (edge)); - loop->num_pre_header_edges = num; - - /* Store edges in order that they are followed. The source of the first edge - is the root node of the pre-header extended basic block and the - destination of the last last edge is the loop header. */ - for (e = loop->entry_edges[0]; num; e = e->src->pred) - loop->pre_header_edges[--num] = e; -} - -/* Return the block for the pre-header of the loop with header - HEADER. Return NULL if there is no pre-header. */ +/* For each loop in the lOOPS tree that has just a single exit + record the exit edge. */ -static basic_block -flow_loop_pre_header_find (basic_block header) +void +mark_single_exit_loops (struct loops *loops) { - basic_block pre_header; + basic_block bb; edge e; + struct loop *loop; + unsigned i; - /* If block p is a predecessor of the header and is the only block - that the header does not dominate, then it is the pre-header. */ - pre_header = NULL; - for (e = header->pred; e; e = e->pred_next) + for (i = 1; i < loops->num; i++) { - basic_block node = e->src; + loop = loops->parray[i]; + if (loop) + loop->single_exit = NULL; + } - if (node != ENTRY_BLOCK_PTR - && ! dominated_by_p (CDI_DOMINATORS, node, header)) + FOR_EACH_BB (bb) + { + edge_iterator ei; + if (bb->loop_father == loops->tree_root) + continue; + FOR_EACH_EDGE (e, ei, bb->succs) { - if (pre_header == NULL) - pre_header = node; - else + if (e->dest == EXIT_BLOCK_PTR) + continue; + + if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) + continue; + + for (loop = bb->loop_father; + loop != e->dest->loop_father; + loop = loop->outer) { - /* There are multiple edges into the header from outside - the loop so there is no pre-header block. */ - pre_header = NULL; - break; + /* If we have already seen an exit, mark this by the edge that + surely does not occur as any exit. */ + if (loop->single_exit) + loop->single_exit = EDGE_SUCC (ENTRY_BLOCK_PTR, 0); + else + loop->single_exit = e; } } } - return pre_header; + for (i = 1; i < loops->num; i++) + { + loop = loops->parray[i]; + if (!loop) + continue; + + if (loop->single_exit == EDGE_SUCC (ENTRY_BLOCK_PTR, 0)) + loop->single_exit = NULL; + } + + loops->state |= LOOPS_HAVE_MARKED_SINGLE_EXITS; } static void @@ -428,6 +332,10 @@ establish_preds (struct loop *loop) struct loop *ploop, *father = loop->outer; loop->depth = father->depth + 1; + + /* Remember the current loop depth if it is the largest seen so far. */ + cfun->max_loop_depth = MAX (cfun->max_loop_depth, loop->depth); + if (loop->pred) free (loop->pred); loop->pred = xmalloc (sizeof (struct loop *) * loop->depth); @@ -509,43 +417,10 @@ flow_loop_level_compute (struct loop *loop) hierarchy tree specified by LOOPS. Return the maximum enclosed loop level. */ -static int +static void flow_loops_level_compute (struct loops *loops) { - return flow_loop_level_compute (loops->tree_root); -} - -/* Scan a single natural loop specified by LOOP collecting information - about it specified by FLAGS. */ - -int -flow_loop_scan (struct loop *loop, int flags) -{ - if (flags & LOOP_ENTRY_EDGES) - { - /* Find edges which enter the loop header. - Note that the entry edges should only - enter the header of a natural loop. */ - flow_loop_entry_edges_find (loop); - } - - if (flags & LOOP_EXIT_EDGES) - { - /* Find edges which exit the loop. */ - flow_loop_exit_edges_find (loop); - } - - if (flags & LOOP_PRE_HEADER) - { - /* Look to see if the loop has a pre-header node. */ - loop->pre_header = flow_loop_pre_header_find (loop->header); - - /* Find the blocks within the extended basic block of - the loop pre-header. */ - flow_loop_pre_header_scan (loop); - } - - return 1; + flow_loop_level_compute (loops->tree_root); } /* A callback to update latch and header info for basic block JUMP created @@ -556,8 +431,9 @@ update_latch_info (basic_block jump) { alloc_aux_for_block (jump, sizeof (int)); HEADER_BLOCK (jump) = 0; - alloc_aux_for_edge (jump->pred, sizeof (int)); - LATCH_EDGE (jump->pred) = 0; + alloc_aux_for_edge (EDGE_PRED (jump, 0), sizeof (int)); + LATCH_EDGE (EDGE_PRED (jump, 0)) = 0; + set_immediate_dominator (CDI_DOMINATORS, jump, EDGE_PRED (jump, 0)->src); } /* A callback for make_forwarder block, to redirect all edges except for @@ -589,19 +465,17 @@ canonicalize_loop_headers (void) basic_block header; edge e; - /* Compute the dominators. */ - calculate_dominance_info (CDI_DOMINATORS); - alloc_aux_for_blocks (sizeof (int)); alloc_aux_for_edges (sizeof (int)); /* Split blocks so that each loop has only single latch. */ FOR_EACH_BB (header) { + edge_iterator ei; int num_latches = 0; int have_abnormal_edge = 0; - for (e = header->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, header->preds) { basic_block latch = e->src; @@ -621,18 +495,16 @@ canonicalize_loop_headers (void) HEADER_BLOCK (header) = num_latches; } - free_dominance_info (CDI_DOMINATORS); - - if (HEADER_BLOCK (ENTRY_BLOCK_PTR->succ->dest)) + if (HEADER_BLOCK (EDGE_SUCC (ENTRY_BLOCK_PTR, 0)->dest)) { basic_block bb; /* We could not redirect edges freely here. On the other hand, we can simply split the edge from entry block. */ - bb = split_edge (ENTRY_BLOCK_PTR->succ); + bb = split_edge (EDGE_SUCC (ENTRY_BLOCK_PTR, 0)); - alloc_aux_for_edge (bb->succ, sizeof (int)); - LATCH_EDGE (bb->succ) = 0; + alloc_aux_for_edge (EDGE_SUCC (bb, 0), sizeof (int)); + LATCH_EDGE (EDGE_SUCC (bb, 0)) = 0; alloc_aux_for_block (bb, sizeof (int)); HEADER_BLOCK (bb) = 0; } @@ -641,6 +513,7 @@ canonicalize_loop_headers (void) { int max_freq, is_heavy; edge heavy, tmp_edge; + edge_iterator ei; if (HEADER_BLOCK (header) <= 1) continue; @@ -649,11 +522,11 @@ canonicalize_loop_headers (void) is_heavy = 1; heavy = NULL; max_freq = 0; - for (e = header->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, header->preds) if (LATCH_EDGE (e) && EDGE_FREQUENCY (e) > max_freq) max_freq = EDGE_FREQUENCY (e); - for (e = header->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, header->preds) if (LATCH_EDGE (e) && EDGE_FREQUENCY (e) >= max_freq / HEAVY_EDGE_RATIO) { @@ -694,17 +567,33 @@ canonicalize_loop_headers (void) free_aux_for_blocks (); free_aux_for_edges (); + +#ifdef ENABLE_CHECKING + verify_dominators (CDI_DOMINATORS); +#endif +} + +/* Initialize all the parallel_p fields of the loops structure to true. */ + +static void +initialize_loops_parallel_p (struct loops *loops) +{ + unsigned int i; + + for (i = 0; i < loops->num; i++) + { + struct loop *loop = loops->parray[i]; + loop->parallel_p = true; + } } /* Find all the natural loops in the function and save in LOOPS structure and - recalculate loop_depth information in basic block structures. FLAGS - controls which loop information is collected. Return the number of natural - loops found. */ + recalculate loop_depth information in basic block structures. + Return the number of natural loops found. */ int -flow_loops_find (struct loops *loops, int flags) +flow_loops_find (struct loops *loops) { - int i; int b; int num_loops; edge e; @@ -714,14 +603,12 @@ flow_loops_find (struct loops *loops, int flags) basic_block header; basic_block bb; - /* This function cannot be repeatedly called with different - flags to build up the loop information. The loop tree - must always be built if this function is called. */ - if (! (flags & LOOP_TREE)) - abort (); - memset (loops, 0, sizeof *loops); + /* We are going to recount the maximum loop depth, + so throw away the last count. */ + cfun->max_loop_depth = 0; + /* Taking care of this degenerate case makes the rest of this code simpler. */ if (n_basic_blocks == 0) @@ -730,12 +617,12 @@ flow_loops_find (struct loops *loops, int flags) dfs_order = NULL; rc_order = NULL; + /* Ensure that the dominators are computed. */ + calculate_dominance_info (CDI_DOMINATORS); + /* Join loops with shared headers. */ canonicalize_loop_headers (); - /* Compute the dominators. */ - calculate_dominance_info (CDI_DOMINATORS); - /* Count the number of loop headers. This should be the same as the number of natural loops. */ headers = sbitmap_alloc (last_basic_block); @@ -744,24 +631,24 @@ flow_loops_find (struct loops *loops, int flags) num_loops = 0; FOR_EACH_BB (header) { + edge_iterator ei; int more_latches = 0; header->loop_depth = 0; /* If we have an abnormal predecessor, do not consider the loop (not worth the problems). */ - for (e = header->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, header->preds) if (e->flags & EDGE_ABNORMAL) break; if (e) continue; - for (e = header->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, header->preds) { basic_block latch = e->src; - if (e->flags & EDGE_ABNORMAL) - abort (); + gcc_assert (!(e->flags & EDGE_ABNORMAL)); /* Look for back edges where a predecessor is dominated by this block. A natural loop has a single entry @@ -772,8 +659,7 @@ flow_loops_find (struct loops *loops, int flags) && dominated_by_p (CDI_DOMINATORS, latch, header)) { /* Shared headers should be eliminated by now. */ - if (more_latches) - abort (); + gcc_assert (!more_latches); more_latches = 1; SET_BIT (headers, header->index); num_loops++; @@ -822,6 +708,7 @@ flow_loops_find (struct loops *loops, int flags) for (b = 0; b < n_basic_blocks; b++) { struct loop *loop; + edge_iterator ei; /* Search the nodes of the CFG in reverse completion order so that we can find outer loops first. */ @@ -837,7 +724,7 @@ flow_loops_find (struct loops *loops, int flags) num_loops++; /* Look for the latch for this header block. */ - for (e = header->pred; e; e = e->pred_next) + FOR_EACH_EDGE (e, ei, header->preds) { basic_block latch = e->src; @@ -855,17 +742,10 @@ flow_loops_find (struct loops *loops, int flags) /* Assign the loop nesting depth and enclosed loop level for each loop. */ - loops->levels = flow_loops_level_compute (loops); - - /* Scan the loops. */ - for (i = 1; i < num_loops; i++) - flow_loop_scan (loops->parray[i], flags); + flow_loops_level_compute (loops); loops->num = num_loops; - } - else - { - free_dominance_info (CDI_DOMINATORS); + initialize_loops_parallel_p (loops); } sbitmap_free (headers); @@ -879,20 +759,6 @@ flow_loops_find (struct loops *loops, int flags) return loops->num; } -/* Update the information regarding the loops in the CFG - specified by LOOPS. */ - -int -flow_loops_update (struct loops *loops, int flags) -{ - /* One day we may want to update the current loop data. For now - throw away the old stuff and rebuild what we need. */ - if (loops->parray) - flow_loops_free (loops); - - return flow_loops_find (loops, flags); -} - /* Return nonzero if basic block BB belongs to LOOP. */ bool flow_bb_inside_loop_p (const struct loop *loop, const basic_block bb) @@ -911,8 +777,7 @@ flow_bb_inside_loop_p (const struct loop *loop, const basic_block bb) bool flow_loop_outside_edge_p (const struct loop *loop, edge e) { - if (e->dest != loop->header) - abort (); + gcc_assert (e->dest == loop->header); return !flow_bb_inside_loop_p (loop, e->src); } @@ -932,8 +797,7 @@ get_loop_body (const struct loop *loop) basic_block *tovisit, bb; unsigned tv = 0; - if (!loop->num_nodes) - abort (); + gcc_assert (loop->num_nodes); tovisit = xcalloc (loop->num_nodes, sizeof (basic_block)); tovisit[tv++] = loop->header; @@ -941,8 +805,7 @@ get_loop_body (const struct loop *loop) if (loop->latch == EXIT_BLOCK_PTR) { /* There may be blocks unreachable from EXIT_BLOCK. */ - if (loop->num_nodes != (unsigned) n_basic_blocks + 2) - abort (); + gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks + 2); FOR_EACH_BB (bb) tovisit[tv++] = bb; tovisit[tv++] = EXIT_BLOCK_PTR; @@ -954,11 +817,114 @@ get_loop_body (const struct loop *loop) loop->header) + 1; } - if (tv != loop->num_nodes) - abort (); + gcc_assert (tv == loop->num_nodes); + return tovisit; +} + +/* Fills dominance descendants inside LOOP of the basic block BB into + array TOVISIT from index *TV. */ + +static void +fill_sons_in_loop (const struct loop *loop, basic_block bb, + basic_block *tovisit, int *tv) +{ + basic_block son, postpone = NULL; + + tovisit[(*tv)++] = bb; + for (son = first_dom_son (CDI_DOMINATORS, bb); + son; + son = next_dom_son (CDI_DOMINATORS, son)) + { + if (!flow_bb_inside_loop_p (loop, son)) + continue; + + if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) + { + postpone = son; + continue; + } + fill_sons_in_loop (loop, son, tovisit, tv); + } + + if (postpone) + fill_sons_in_loop (loop, postpone, tovisit, tv); +} + +/* Gets body of a LOOP (that must be different from the outermost loop) + sorted by dominance relation. Additionally, if a basic block s dominates + the latch, then only blocks dominated by s are be after it. */ + +basic_block * +get_loop_body_in_dom_order (const struct loop *loop) +{ + basic_block *tovisit; + int tv; + + gcc_assert (loop->num_nodes); + + tovisit = xcalloc (loop->num_nodes, sizeof (basic_block)); + + gcc_assert (loop->latch != EXIT_BLOCK_PTR); + + tv = 0; + fill_sons_in_loop (loop, loop->header, tovisit, &tv); + + gcc_assert (tv == (int) loop->num_nodes); + return tovisit; } +/* Get body of a LOOP in breadth first sort order. */ + +basic_block * +get_loop_body_in_bfs_order (const struct loop *loop) +{ + basic_block *blocks; + basic_block bb; + bitmap visited; + unsigned int i = 0; + unsigned int vc = 1; + + gcc_assert (loop->num_nodes); + gcc_assert (loop->latch != EXIT_BLOCK_PTR); + + blocks = xcalloc (loop->num_nodes, sizeof (basic_block)); + visited = BITMAP_ALLOC (NULL); + + bb = loop->header; + while (i < loop->num_nodes) + { + edge e; + edge_iterator ei; + + if (!bitmap_bit_p (visited, bb->index)) + { + /* This basic block is now visited */ + bitmap_set_bit (visited, bb->index); + blocks[i++] = bb; + } + + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (flow_bb_inside_loop_p (loop, e->dest)) + { + if (!bitmap_bit_p (visited, e->dest->index)) + { + bitmap_set_bit (visited, e->dest->index); + blocks[i++] = e->dest; + } + } + } + + gcc_assert (i >= vc); + + bb = blocks[vc++]; + } + + BITMAP_FREE (visited); + return blocks; +} + /* Gets exit edges of a LOOP, returning their number in N_EDGES. */ edge * get_loop_exit_edges (const struct loop *loop, unsigned int *n_edges) @@ -966,21 +932,21 @@ get_loop_exit_edges (const struct loop *loop, unsigned int *n_edges) edge *edges, e; unsigned i, n; basic_block * body; + edge_iterator ei; - if (loop->latch == EXIT_BLOCK_PTR) - abort (); + gcc_assert (loop->latch != EXIT_BLOCK_PTR); body = get_loop_body (loop); n = 0; for (i = 0; i < loop->num_nodes; i++) - for (e = body[i]->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, body[i]->succs) if (!flow_bb_inside_loop_p (loop, e->dest)) n++; edges = xmalloc (n * sizeof (edge)); *n_edges = n; n = 0; for (i = 0; i < loop->num_nodes; i++) - for (e = body[i]->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, body[i]->succs) if (!flow_bb_inside_loop_p (loop, e->dest)) edges[n++] = e; free (body); @@ -988,6 +954,26 @@ get_loop_exit_edges (const struct loop *loop, unsigned int *n_edges) return edges; } +/* Counts the number of conditional branches inside LOOP. */ + +unsigned +num_loop_branches (const struct loop *loop) +{ + unsigned i, n; + basic_block * body; + + gcc_assert (loop->latch != EXIT_BLOCK_PTR); + + body = get_loop_body (loop); + n = 0; + for (i = 0; i < loop->num_nodes; i++) + if (EDGE_COUNT (body[i]->succs) >= 2) + n++; + free (body); + + return n; +} + /* Adds basic block BB to LOOP. */ void add_bb_to_loop (basic_block bb, struct loop *loop) @@ -1013,7 +999,7 @@ remove_bb_from_loops (basic_block bb) loop->pred[i]->num_nodes--; bb->loop_father = NULL; bb->loop_depth = 0; - } +} /* Finds nearest common ancestor in loop tree for given loops. */ struct loop * @@ -1042,8 +1028,7 @@ cancel_loop (struct loops *loops, struct loop *loop) basic_block *bbs; unsigned i; - if (loop->inner) - abort (); + gcc_assert (!loop->inner); /* Move blocks up one level (they should be removed as soon as possible). */ bbs = get_loop_body (loop); @@ -1107,8 +1092,6 @@ verify_loop_structure (struct loops *loops) } } - free (sizes); - /* Check get_loop_body. */ for (i = 1; i < loops->num; i++) { @@ -1135,21 +1118,19 @@ verify_loop_structure (struct loops *loops) continue; if ((loops->state & LOOPS_HAVE_PREHEADERS) - && (!loop->header->pred->pred_next - || loop->header->pred->pred_next->pred_next)) + && EDGE_COUNT (loop->header->preds) != 2) { error ("Loop %d's header does not have exactly 2 entries.", i); err = 1; } if (loops->state & LOOPS_HAVE_SIMPLE_LATCHES) { - if (!loop->latch->succ - || loop->latch->succ->succ_next) + if (EDGE_COUNT (loop->latch->succs) != 1) { error ("Loop %d's latch does not have exactly 1 successor.", i); err = 1; } - if (loop->latch->succ->dest != loop->header) + if (EDGE_SUCC (loop->latch, 0)->dest != loop->header) { error ("Loop %d's latch does not have header as successor.", i); err = 1; @@ -1180,11 +1161,12 @@ verify_loop_structure (struct loops *loops) irreds = sbitmap_alloc (last_basic_block); FOR_EACH_BB (bb) { + edge_iterator ei; if (bb->flags & BB_IRREDUCIBLE_LOOP) SET_BIT (irreds, bb->index); else RESET_BIT (irreds, bb->index); - for (e = bb->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, bb->succs) if (e->flags & EDGE_IRREDUCIBLE_LOOP) e->flags |= EDGE_ALL_FLAGS + 1; } @@ -1195,6 +1177,8 @@ verify_loop_structure (struct loops *loops) /* Compare. */ FOR_EACH_BB (bb) { + edge_iterator ei; + if ((bb->flags & BB_IRREDUCIBLE_LOOP) && !TEST_BIT (irreds, bb->index)) { @@ -1207,7 +1191,7 @@ verify_loop_structure (struct loops *loops) error ("Basic block %d should not be marked irreducible.", bb->index); err = 1; } - for (e = bb->succ; e; e = e->succ_next) + FOR_EACH_EDGE (e, ei, bb->succs) { if ((e->flags & EDGE_IRREDUCIBLE_LOOP) && !(e->flags & (EDGE_ALL_FLAGS + 1))) @@ -1229,20 +1213,78 @@ verify_loop_structure (struct loops *loops) free (irreds); } - if (err) - abort (); + /* Check the single_exit. */ + if (loops->state & LOOPS_HAVE_MARKED_SINGLE_EXITS) + { + memset (sizes, 0, sizeof (unsigned) * loops->num); + FOR_EACH_BB (bb) + { + edge_iterator ei; + if (bb->loop_father == loops->tree_root) + continue; + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (e->dest == EXIT_BLOCK_PTR) + continue; + + if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) + continue; + + for (loop = bb->loop_father; + loop != e->dest->loop_father; + loop = loop->outer) + { + sizes[loop->num]++; + if (loop->single_exit + && loop->single_exit != e) + { + error ("Wrong single exit %d->%d recorded for loop %d.", + loop->single_exit->src->index, + loop->single_exit->dest->index, + loop->num); + error ("Right exit is %d->%d.", + e->src->index, e->dest->index); + err = 1; + } + } + } + } + + for (i = 1; i < loops->num; i++) + { + loop = loops->parray[i]; + if (!loop) + continue; + + if (sizes[i] == 1 + && !loop->single_exit) + { + error ("Single exit not recorded for loop %d.", loop->num); + err = 1; + } + + if (sizes[i] != 1 + && loop->single_exit) + { + error ("Loop %d should not have single exit (%d -> %d).", + loop->num, + loop->single_exit->src->index, + loop->single_exit->dest->index); + err = 1; + } + } + } + + gcc_assert (!err); + + free (sizes); } /* Returns latch edge of LOOP. */ edge loop_latch_edge (const struct loop *loop) { - edge e; - - for (e = loop->header->pred; e->src != loop->latch; e = e->pred_next) - continue; - - return e; + return find_edge (loop->latch, loop->header); } /* Returns preheader edge of LOOP. */ @@ -1250,9 +1292,20 @@ edge loop_preheader_edge (const struct loop *loop) { edge e; + edge_iterator ei; - for (e = loop->header->pred; e->src == loop->latch; e = e->pred_next) - continue; + FOR_EACH_EDGE (e, ei, loop->header->preds) + if (e->src != loop->latch) + break; return e; } + +/* Returns true if E is an exit of LOOP. */ + +bool +loop_exit_edge_p (const struct loop *loop, edge e) +{ + return (flow_bb_inside_loop_p (loop, e->src) + && !flow_bb_inside_loop_p (loop, e->dest)); +}