/* Instruction scheduling pass. Copyright (C) 1992-2024 Free Software Foundation, Inc. Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by, and currently maintained by, Jim Wilson (wilson@cygnus.com) 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 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ /* This pass implements list scheduling within basic blocks. It is run twice: (1) after flow analysis, but before register allocation, and (2) after register allocation. The first run performs interblock scheduling, moving insns between different blocks in the same "region", and the second runs only basic block scheduling. Interblock motions performed are useful motions and speculative motions, including speculative loads. Motions requiring code duplication are not supported. The identification of motion type and the check for validity of speculative motions requires construction and analysis of the function's control flow graph. The main entry point for this pass is schedule_insns(), called for each function. The work of the scheduler is organized in three levels: (1) function level: insns are subject to splitting, control-flow-graph is constructed, regions are computed (after reload, each region is of one block), (2) region level: control flow graph attributes required for interblock scheduling are computed (dominators, reachability, etc.), data dependences and priorities are computed, and (3) block level: insns in the block are actually scheduled. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "backend.h" #include "target.h" #include "rtl.h" #include "df.h" #include "memmodel.h" #include "tm_p.h" #include "insn-config.h" #include "emit-rtl.h" #include "recog.h" #include "profile.h" #include "insn-attr.h" #include "except.h" #include "cfganal.h" #include "sched-int.h" #include "sel-sched.h" #include "tree-pass.h" #include "dbgcnt.h" #include "pretty-print.h" #include "print-rtl.h" /* Disable warnings about quoting issues in the pp_xxx calls below that (intentionally) don't follow GCC diagnostic conventions. */ #if __GNUC__ >= 10 # pragma GCC diagnostic push # pragma GCC diagnostic ignored "-Wformat-diag" #endif #ifdef INSN_SCHEDULING /* Some accessor macros for h_i_d members only used within this file. */ #define FED_BY_SPEC_LOAD(INSN) (HID (INSN)->fed_by_spec_load) #define IS_LOAD_INSN(INSN) (HID (insn)->is_load_insn) /* nr_inter/spec counts interblock/speculative motion for the function. */ static int nr_inter, nr_spec; static bool is_cfg_nonregular (void); /* Number of regions in the procedure. */ int nr_regions = 0; /* Same as above before adding any new regions. */ static int nr_regions_initial = 0; /* Table of region descriptions. */ region *rgn_table = NULL; /* Array of lists of regions' blocks. */ int *rgn_bb_table = NULL; /* Topological order of blocks in the region (if b2 is reachable from b1, block_to_bb[b2] > block_to_bb[b1]). Note: A basic block is always referred to by either block or b, while its topological order name (in the region) is referred to by bb. */ int *block_to_bb = NULL; /* The number of the region containing a block. */ int *containing_rgn = NULL; /* ebb_head [i] - is index in rgn_bb_table of the head basic block of i'th ebb. Currently we can get a ebb only through splitting of currently scheduling block, therefore, we don't need ebb_head array for every region, hence, its sufficient to hold it for current one only. */ int *ebb_head = NULL; /* The minimum probability of reaching a source block so that it will be considered for speculative scheduling. */ static int min_spec_prob; static void find_single_block_region (bool); static void find_rgns (void); static bool too_large (int, int *, int *); /* Blocks of the current region being scheduled. */ int current_nr_blocks; int current_blocks; /* A speculative motion requires checking live information on the path from 'source' to 'target'. The split blocks are those to be checked. After a speculative motion, live information should be modified in the 'update' blocks. Lists of split and update blocks for each candidate of the current target are in array bblst_table. */ static basic_block *bblst_table; static int bblst_size, bblst_last; /* Arrays that hold the DFA state at the end of a basic block, to re-use as the initial state at the start of successor blocks. The BB_STATE array holds the actual DFA state, and BB_STATE_ARRAY[I] is a pointer into BB_STATE for basic block I. FIXME: This should be a vec. */ static char *bb_state_array = NULL; static state_t *bb_state = NULL; /* Target info declarations. The block currently being scheduled is referred to as the "target" block, while other blocks in the region from which insns can be moved to the target are called "source" blocks. The candidate structure holds info about such sources: are they valid? Speculative? Etc. */ struct bblst { basic_block *first_member; int nr_members; }; struct candidate { char is_valid; char is_speculative; int src_prob; bblst split_bbs; bblst update_bbs; }; static candidate *candidate_table; #define IS_VALID(src) (candidate_table[src].is_valid) #define IS_SPECULATIVE(src) (candidate_table[src].is_speculative) #define IS_SPECULATIVE_INSN(INSN) \ (IS_SPECULATIVE (BLOCK_TO_BB (BLOCK_NUM (INSN)))) #define SRC_PROB(src) ( candidate_table[src].src_prob ) /* The bb being currently scheduled. */ int target_bb; /* List of edges. */ struct edgelst { edge *first_member; int nr_members; }; static edge *edgelst_table; static int edgelst_last; static void extract_edgelst (sbitmap, edgelst *); /* Target info functions. */ static void split_edges (int, int, edgelst *); static void compute_trg_info (int); void debug_candidate (int); void debug_candidates (int); /* Dominators array: dom[i] contains the sbitmap of dominators of bb i in the region. */ static sbitmap *dom; /* bb 0 is the only region entry. */ #define IS_RGN_ENTRY(bb) (!bb) /* Is bb_src dominated by bb_trg. */ #define IS_DOMINATED(bb_src, bb_trg) \ ( bitmap_bit_p (dom[bb_src], bb_trg) ) /* Probability: Prob[i] is an int in [0, REG_BR_PROB_BASE] which is the probability of bb i relative to the region entry. */ static int *prob; /* Bit-set of edges, where bit i stands for edge i. */ typedef sbitmap edgeset; /* Number of edges in the region. */ static int rgn_nr_edges; /* Array of size rgn_nr_edges. */ static edge *rgn_edges; /* Mapping from each edge in the graph to its number in the rgn. */ #define EDGE_TO_BIT(edge) ((int)(size_t)(edge)->aux) #define SET_EDGE_TO_BIT(edge,nr) ((edge)->aux = (void *)(size_t)(nr)) /* The split edges of a source bb is different for each target bb. In order to compute this efficiently, the 'potential-split edges' are computed for each bb prior to scheduling a region. This is actually the split edges of each bb relative to the region entry. pot_split[bb] is the set of potential split edges of bb. */ static edgeset *pot_split; /* For every bb, a set of its ancestor edges. */ static edgeset *ancestor_edges; #define INSN_PROBABILITY(INSN) (SRC_PROB (BLOCK_TO_BB (BLOCK_NUM (INSN)))) /* Speculative scheduling functions. */ static bool check_live_1 (int, rtx); static void update_live_1 (int, rtx); static bool is_pfree (rtx, int, int); static bool find_conditional_protection (rtx_insn *, int); static bool is_conditionally_protected (rtx, int, int); static bool is_prisky (rtx, int, int); static bool is_exception_free (rtx_insn *, int, int); static bool sets_likely_spilled (rtx); static void sets_likely_spilled_1 (rtx, const_rtx, void *); static void add_branch_dependences (rtx_insn *, rtx_insn *); static void compute_block_dependences (int); static void schedule_region (int); static void concat_insn_mem_list (rtx_insn_list *, rtx_expr_list *, rtx_insn_list **, rtx_expr_list **); static void propagate_deps (int, class deps_desc *); static void free_pending_lists (void); /* Functions for construction of the control flow graph. */ /* Return true if control flow graph should not be constructed, false otherwise. We decide not to build the control flow graph if there is possibly more than one entry to the function, if computed branches exist, if we have nonlocal gotos, or if we have an unreachable loop. */ static bool is_cfg_nonregular (void) { basic_block b; rtx_insn *insn; /* If we have a label that could be the target of a nonlocal goto, then the cfg is not well structured. */ if (nonlocal_goto_handler_labels) return true; /* If we have any forced labels, then the cfg is not well structured. */ if (forced_labels) return true; /* If we have exception handlers, then we consider the cfg not well structured. ?!? We should be able to handle this now that we compute an accurate cfg for EH. */ if (current_function_has_exception_handlers ()) return true; /* If we have insns which refer to labels as non-jumped-to operands, then we consider the cfg not well structured. */ FOR_EACH_BB_FN (b, cfun) FOR_BB_INSNS (b, insn) { rtx note, set, dest; rtx_insn *next; /* If this function has a computed jump, then we consider the cfg not well structured. */ if (JUMP_P (insn) && computed_jump_p (insn)) return true; if (!INSN_P (insn)) continue; note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX); if (note == NULL_RTX) continue; /* For that label not to be seen as a referred-to label, this must be a single-set which is feeding a jump *only*. This could be a conditional jump with the label split off for machine-specific reasons or a casesi/tablejump. */ next = next_nonnote_insn (insn); if (next == NULL_RTX || !JUMP_P (next) || (JUMP_LABEL (next) != XEXP (note, 0) && find_reg_note (next, REG_LABEL_TARGET, XEXP (note, 0)) == NULL_RTX) || BLOCK_FOR_INSN (insn) != BLOCK_FOR_INSN (next)) return true; set = single_set (insn); if (set == NULL_RTX) return true; dest = SET_DEST (set); if (!REG_P (dest) || !dead_or_set_p (next, dest)) return true; } /* Unreachable loops with more than one basic block are detected during the DFS traversal in find_rgns. Unreachable loops with a single block are detected here. This test is redundant with the one in find_rgns, but it's much cheaper to go ahead and catch the trivial case here. */ FOR_EACH_BB_FN (b, cfun) { if (EDGE_COUNT (b->preds) == 0 || (single_pred_p (b) && single_pred (b) == b)) return true; } /* All the tests passed. Consider the cfg well structured. */ return false; } /* Extract list of edges from a bitmap containing EDGE_TO_BIT bits. */ static void extract_edgelst (sbitmap set, edgelst *el) { unsigned int i = 0; sbitmap_iterator sbi; /* edgelst table space is reused in each call to extract_edgelst. */ edgelst_last = 0; el->first_member = &edgelst_table[edgelst_last]; el->nr_members = 0; /* Iterate over each word in the bitset. */ EXECUTE_IF_SET_IN_BITMAP (set, 0, i, sbi) { edgelst_table[edgelst_last++] = rgn_edges[i]; el->nr_members++; } } /* Functions for the construction of regions. */ /* Print the regions, for debugging purposes. Callable from debugger. */ DEBUG_FUNCTION void debug_regions (void) { int rgn, bb; fprintf (sched_dump, "\n;; ------------ REGIONS ----------\n\n"); for (rgn = 0; rgn < nr_regions; rgn++) { fprintf (sched_dump, ";;\trgn %d nr_blocks %d:\n", rgn, rgn_table[rgn].rgn_nr_blocks); fprintf (sched_dump, ";;\tbb/block: "); /* We don't have ebb_head initialized yet, so we can't use BB_TO_BLOCK (). */ current_blocks = RGN_BLOCKS (rgn); for (bb = 0; bb < rgn_table[rgn].rgn_nr_blocks; bb++) fprintf (sched_dump, " %d/%d ", bb, rgn_bb_table[current_blocks + bb]); fprintf (sched_dump, "\n\n"); } } /* Print the region's basic blocks. */ DEBUG_FUNCTION void debug_region (int rgn) { int bb; fprintf (stderr, "\n;; ------------ REGION %d ----------\n\n", rgn); fprintf (stderr, ";;\trgn %d nr_blocks %d:\n", rgn, rgn_table[rgn].rgn_nr_blocks); fprintf (stderr, ";;\tbb/block: "); /* We don't have ebb_head initialized yet, so we can't use BB_TO_BLOCK (). */ current_blocks = RGN_BLOCKS (rgn); for (bb = 0; bb < rgn_table[rgn].rgn_nr_blocks; bb++) fprintf (stderr, " %d/%d ", bb, rgn_bb_table[current_blocks + bb]); fprintf (stderr, "\n\n"); for (bb = 0; bb < rgn_table[rgn].rgn_nr_blocks; bb++) { dump_bb (stderr, BASIC_BLOCK_FOR_FN (cfun, rgn_bb_table[current_blocks + bb]), 0, TDF_SLIM | TDF_BLOCKS); fprintf (stderr, "\n"); } fprintf (stderr, "\n"); } /* True when a bb with index BB_INDEX contained in region RGN. */ static bool bb_in_region_p (int bb_index, int rgn) { int i; for (i = 0; i < rgn_table[rgn].rgn_nr_blocks; i++) if (rgn_bb_table[current_blocks + i] == bb_index) return true; return false; } /* Dump region RGN to file F using dot syntax. */ void dump_region_dot (FILE *f, int rgn) { int i; fprintf (f, "digraph Region_%d {\n", rgn); /* We don't have ebb_head initialized yet, so we can't use BB_TO_BLOCK (). */ current_blocks = RGN_BLOCKS (rgn); for (i = 0; i < rgn_table[rgn].rgn_nr_blocks; i++) { edge e; edge_iterator ei; int src_bb_num = rgn_bb_table[current_blocks + i]; basic_block bb = BASIC_BLOCK_FOR_FN (cfun, src_bb_num); FOR_EACH_EDGE (e, ei, bb->succs) if (bb_in_region_p (e->dest->index, rgn)) fprintf (f, "\t%d -> %d\n", src_bb_num, e->dest->index); } fprintf (f, "}\n"); } /* The same, but first open a file specified by FNAME. */ void dump_region_dot_file (const char *fname, int rgn) { FILE *f = fopen (fname, "wt"); dump_region_dot (f, rgn); fclose (f); } /* Build a single block region for each basic block in the function. This allows for using the same code for interblock and basic block scheduling. */ static void find_single_block_region (bool ebbs_p) { basic_block bb, ebb_start; int i = 0; nr_regions = 0; if (ebbs_p) { int probability_cutoff; if (profile_info && profile_status_for_fn (cfun) == PROFILE_READ) probability_cutoff = param_tracer_min_branch_probability_feedback; else probability_cutoff = param_tracer_min_branch_probability; probability_cutoff = REG_BR_PROB_BASE / 100 * probability_cutoff; FOR_EACH_BB_FN (ebb_start, cfun) { RGN_NR_BLOCKS (nr_regions) = 0; RGN_BLOCKS (nr_regions) = i; RGN_DONT_CALC_DEPS (nr_regions) = 0; RGN_HAS_REAL_EBB (nr_regions) = 0; for (bb = ebb_start; ; bb = bb->next_bb) { edge e; rgn_bb_table[i] = bb->index; RGN_NR_BLOCKS (nr_regions)++; CONTAINING_RGN (bb->index) = nr_regions; BLOCK_TO_BB (bb->index) = i - RGN_BLOCKS (nr_regions); i++; if (bb->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || LABEL_P (BB_HEAD (bb->next_bb))) break; e = find_fallthru_edge (bb->succs); if (! e) break; if (e->probability.initialized_p () && e->probability.to_reg_br_prob_base () <= probability_cutoff) break; } ebb_start = bb; nr_regions++; } } else FOR_EACH_BB_FN (bb, cfun) { rgn_bb_table[nr_regions] = bb->index; RGN_NR_BLOCKS (nr_regions) = 1; RGN_BLOCKS (nr_regions) = nr_regions; RGN_DONT_CALC_DEPS (nr_regions) = 0; RGN_HAS_REAL_EBB (nr_regions) = 0; CONTAINING_RGN (bb->index) = nr_regions; BLOCK_TO_BB (bb->index) = 0; nr_regions++; } } /* Estimate number of the insns in the BB. */ static int rgn_estimate_number_of_insns (basic_block bb) { int count; count = INSN_LUID (BB_END (bb)) - INSN_LUID (BB_HEAD (bb)); if (MAY_HAVE_DEBUG_INSNS) { rtx_insn *insn; FOR_BB_INSNS (bb, insn) if (DEBUG_INSN_P (insn)) count--; } return count; } /* Update number of blocks and the estimate for number of insns in the region. Return true if the region is "too large" for interblock scheduling (compile time considerations). */ static bool too_large (int block, int *num_bbs, int *num_insns) { (*num_bbs)++; (*num_insns) += (common_sched_info->estimate_number_of_insns (BASIC_BLOCK_FOR_FN (cfun, block))); return ((*num_bbs > param_max_sched_region_blocks) || (*num_insns > param_max_sched_region_insns)); } /* Update_loop_relations(blk, hdr): Check if the loop headed by max_hdr[blk] is still an inner loop. Put in max_hdr[blk] the header of the most inner loop containing blk. */ #define UPDATE_LOOP_RELATIONS(blk, hdr) \ { \ if (max_hdr[blk] == -1) \ max_hdr[blk] = hdr; \ else if (dfs_nr[max_hdr[blk]] > dfs_nr[hdr]) \ bitmap_clear_bit (inner, hdr); \ else if (dfs_nr[max_hdr[blk]] < dfs_nr[hdr]) \ { \ bitmap_clear_bit (inner,max_hdr[blk]); \ max_hdr[blk] = hdr; \ } \ } /* Find regions for interblock scheduling. A region for scheduling can be: * A loop-free procedure, or * A reducible inner loop, or * A basic block not contained in any other region. ?!? In theory we could build other regions based on extended basic blocks or reverse extended basic blocks. Is it worth the trouble? Loop blocks that form a region are put into the region's block list in topological order. This procedure stores its results into the following global (ick) variables * rgn_nr * rgn_table * rgn_bb_table * block_to_bb * containing region We use dominator relationships to avoid making regions out of non-reducible loops. This procedure needs to be converted to work on pred/succ lists instead of edge tables. That would simplify it somewhat. */ static void haifa_find_rgns (void) { int *max_hdr, *dfs_nr, *degree; char no_loops = 1; int node, child, loop_head, i, head, tail; int count = 0, sp, idx = 0; edge_iterator current_edge; edge_iterator *stack; int num_bbs, num_insns; bool unreachable; bool too_large_failure; basic_block bb; /* Perform a DFS traversal of the cfg. Identify loop headers, inner loops and a mapping from block to its loop header (if the block is contained in a loop, else -1). Store results in HEADER, INNER, and MAX_HDR respectively, these will be used as inputs to the second traversal. STACK, SP and DFS_NR are only used during the first traversal. */ /* Allocate and initialize variables for the first traversal. */ max_hdr = XNEWVEC (int, last_basic_block_for_fn (cfun)); dfs_nr = XCNEWVEC (int, last_basic_block_for_fn (cfun)); stack = XNEWVEC (edge_iterator, n_edges_for_fn (cfun)); /* Note if a block is a natural inner loop header. */ auto_sbitmap inner (last_basic_block_for_fn (cfun)); bitmap_ones (inner); /* Note if a block is a natural loop header. */ auto_sbitmap header (last_basic_block_for_fn (cfun)); bitmap_clear (header); /* Note if a block is in the block queue. */ auto_sbitmap in_queue (last_basic_block_for_fn (cfun)); bitmap_clear (in_queue); /* Note if a block is in the block queue. */ auto_sbitmap in_stack (last_basic_block_for_fn (cfun)); bitmap_clear (in_stack); for (i = 0; i < last_basic_block_for_fn (cfun); i++) max_hdr[i] = -1; #define EDGE_PASSED(E) (ei_end_p ((E)) || ei_edge ((E))->aux) #define SET_EDGE_PASSED(E) (ei_edge ((E))->aux = ei_edge ((E))) /* DFS traversal to find inner loops in the cfg. */ current_edge = ei_start (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))->succs); sp = -1; while (1) { if (EDGE_PASSED (current_edge)) { /* We have reached a leaf node or a node that was already processed. Pop edges off the stack until we find an edge that has not yet been processed. */ while (sp >= 0 && EDGE_PASSED (current_edge)) { /* Pop entry off the stack. */ current_edge = stack[sp--]; node = ei_edge (current_edge)->src->index; gcc_assert (node != ENTRY_BLOCK); child = ei_edge (current_edge)->dest->index; gcc_assert (child != EXIT_BLOCK); bitmap_clear_bit (in_stack, child); if (max_hdr[child] >= 0 && bitmap_bit_p (in_stack, max_hdr[child])) UPDATE_LOOP_RELATIONS (node, max_hdr[child]); ei_next (¤t_edge); } /* See if have finished the DFS tree traversal. */ if (sp < 0 && EDGE_PASSED (current_edge)) break; /* Nope, continue the traversal with the popped node. */ continue; } /* Process a node. */ node = ei_edge (current_edge)->src->index; gcc_assert (node != ENTRY_BLOCK); bitmap_set_bit (in_stack, node); dfs_nr[node] = ++count; /* We don't traverse to the exit block. */ child = ei_edge (current_edge)->dest->index; if (child == EXIT_BLOCK) { SET_EDGE_PASSED (current_edge); ei_next (¤t_edge); continue; } /* If the successor is in the stack, then we've found a loop. Mark the loop, if it is not a natural loop, then it will be rejected during the second traversal. */ if (bitmap_bit_p (in_stack, child)) { no_loops = 0; bitmap_set_bit (header, child); UPDATE_LOOP_RELATIONS (node, child); SET_EDGE_PASSED (current_edge); ei_next (¤t_edge); continue; } /* If the child was already visited, then there is no need to visit it again. Just update the loop relationships and restart with a new edge. */ if (dfs_nr[child]) { if (max_hdr[child] >= 0 && bitmap_bit_p (in_stack, max_hdr[child])) UPDATE_LOOP_RELATIONS (node, max_hdr[child]); SET_EDGE_PASSED (current_edge); ei_next (¤t_edge); continue; } /* Push an entry on the stack and continue DFS traversal. */ stack[++sp] = current_edge; SET_EDGE_PASSED (current_edge); current_edge = ei_start (ei_edge (current_edge)->dest->succs); } /* Reset ->aux field used by EDGE_PASSED. */ FOR_ALL_BB_FN (bb, cfun) { edge_iterator ei; edge e; FOR_EACH_EDGE (e, ei, bb->succs) e->aux = NULL; } /* Another check for unreachable blocks. The earlier test in is_cfg_nonregular only finds unreachable blocks that do not form a loop. The DFS traversal will mark every block that is reachable from the entry node by placing a nonzero value in dfs_nr. Thus if dfs_nr is zero for any block, then it must be unreachable. */ unreachable = false; FOR_EACH_BB_FN (bb, cfun) if (dfs_nr[bb->index] == 0) { unreachable = true; break; } /* Gross. To avoid wasting memory, the second pass uses the dfs_nr array to hold degree counts. */ degree = dfs_nr; FOR_EACH_BB_FN (bb, cfun) degree[bb->index] = EDGE_COUNT (bb->preds); /* Do not perform region scheduling if there are any unreachable blocks. */ if (!unreachable) { int *queue, *degree1 = NULL; /* We use EXTENDED_RGN_HEADER as an addition to HEADER and put there basic blocks, which are forced to be region heads. This is done to try to assemble few smaller regions from a too_large region. */ sbitmap extended_rgn_header = NULL; bool extend_regions_p; if (no_loops) bitmap_set_bit (header, 0); /* Second traversal:find reducible inner loops and topologically sort block of each region. */ queue = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); extend_regions_p = param_max_sched_extend_regions_iters > 0; if (extend_regions_p) { degree1 = XNEWVEC (int, last_basic_block_for_fn (cfun)); extended_rgn_header = sbitmap_alloc (last_basic_block_for_fn (cfun)); bitmap_clear (extended_rgn_header); } /* Find blocks which are inner loop headers. We still have non-reducible loops to consider at this point. */ FOR_EACH_BB_FN (bb, cfun) { if (bitmap_bit_p (header, bb->index) && bitmap_bit_p (inner, bb->index)) { edge e; edge_iterator ei; basic_block jbb; /* Now check that the loop is reducible. We do this separate from finding inner loops so that we do not find a reducible loop which contains an inner non-reducible loop. A simple way to find reducible/natural loops is to verify that each block in the loop is dominated by the loop header. If there exists a block that is not dominated by the loop header, then the block is reachable from outside the loop and thus the loop is not a natural loop. */ FOR_EACH_BB_FN (jbb, cfun) { /* First identify blocks in the loop, except for the loop entry block. */ if (bb->index == max_hdr[jbb->index] && bb != jbb) { /* Now verify that the block is dominated by the loop header. */ if (!dominated_by_p (CDI_DOMINATORS, jbb, bb)) break; } } /* If we exited the loop early, then I is the header of a non-reducible loop and we should quit processing it now. */ if (jbb != EXIT_BLOCK_PTR_FOR_FN (cfun)) continue; /* I is a header of an inner loop, or block 0 in a subroutine with no loops at all. */ head = tail = -1; too_large_failure = false; loop_head = max_hdr[bb->index]; if (extend_regions_p) /* We save degree in case when we meet a too_large region and cancel it. We need a correct degree later when calling extend_rgns. */ memcpy (degree1, degree, last_basic_block_for_fn (cfun) * sizeof (int)); /* Decrease degree of all I's successors for topological ordering. */ FOR_EACH_EDGE (e, ei, bb->succs) if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) --degree[e->dest->index]; /* Estimate # insns, and count # blocks in the region. */ num_bbs = 1; num_insns = common_sched_info->estimate_number_of_insns (bb); /* Find all loop latches (blocks with back edges to the loop header) or all the leaf blocks in the cfg has no loops. Place those blocks into the queue. */ if (no_loops) { FOR_EACH_BB_FN (jbb, cfun) /* Leaf nodes have only a single successor which must be EXIT_BLOCK. */ if (single_succ_p (jbb) && single_succ (jbb) == EXIT_BLOCK_PTR_FOR_FN (cfun)) { queue[++tail] = jbb->index; bitmap_set_bit (in_queue, jbb->index); if (too_large (jbb->index, &num_bbs, &num_insns)) { too_large_failure = true; break; } } } else { edge e; FOR_EACH_EDGE (e, ei, bb->preds) { if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) continue; node = e->src->index; if (max_hdr[node] == loop_head && node != bb->index) { /* This is a loop latch. */ queue[++tail] = node; bitmap_set_bit (in_queue, node); if (too_large (node, &num_bbs, &num_insns)) { too_large_failure = true; break; } } } } /* Now add all the blocks in the loop to the queue. We know the loop is a natural loop; however the algorithm above will not always mark certain blocks as being in the loop. Consider: node children a b,c b c c a,d d b The algorithm in the DFS traversal may not mark B & D as part of the loop (i.e. they will not have max_hdr set to A). We know they cannot be loop latches (else they would have had max_hdr set since they'd have a backedge to a dominator block). So we don't need them on the initial queue. We know they are part of the loop because they are dominated by the loop header and can be reached by a backwards walk of the edges starting with nodes on the initial queue. It is safe and desirable to include those nodes in the loop/scheduling region. To do so we would need to decrease the degree of a node if it is the target of a backedge within the loop itself as the node is placed in the queue. We do not do this because I'm not sure that the actual scheduling code will properly handle this case. ?!? */ while (head < tail && !too_large_failure) { edge e; child = queue[++head]; FOR_EACH_EDGE (e, ei, BASIC_BLOCK_FOR_FN (cfun, child)->preds) { node = e->src->index; /* See discussion above about nodes not marked as in this loop during the initial DFS traversal. */ if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || max_hdr[node] != loop_head) { tail = -1; break; } else if (!bitmap_bit_p (in_queue, node) && node != bb->index) { queue[++tail] = node; bitmap_set_bit (in_queue, node); if (too_large (node, &num_bbs, &num_insns)) { too_large_failure = true; break; } } } } if (tail >= 0 && !too_large_failure) { /* Place the loop header into list of region blocks. */ degree[bb->index] = -1; rgn_bb_table[idx] = bb->index; RGN_NR_BLOCKS (nr_regions) = num_bbs; RGN_BLOCKS (nr_regions) = idx++; RGN_DONT_CALC_DEPS (nr_regions) = 0; RGN_HAS_REAL_EBB (nr_regions) = 0; CONTAINING_RGN (bb->index) = nr_regions; BLOCK_TO_BB (bb->index) = count = 0; /* Remove blocks from queue[] when their in degree becomes zero. Repeat until no blocks are left on the list. This produces a topological list of blocks in the region. */ while (tail >= 0) { if (head < 0) head = tail; child = queue[head]; if (degree[child] == 0) { edge e; degree[child] = -1; rgn_bb_table[idx++] = child; BLOCK_TO_BB (child) = ++count; CONTAINING_RGN (child) = nr_regions; queue[head] = queue[tail--]; FOR_EACH_EDGE (e, ei, BASIC_BLOCK_FOR_FN (cfun, child)->succs) if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) --degree[e->dest->index]; } else --head; } ++nr_regions; } else if (extend_regions_p) { /* Restore DEGREE. */ int *t = degree; degree = degree1; degree1 = t; /* And force successors of BB to be region heads. This may provide several smaller regions instead of one too_large region. */ FOR_EACH_EDGE (e, ei, bb->succs) if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) bitmap_set_bit (extended_rgn_header, e->dest->index); } } } free (queue); if (extend_regions_p) { free (degree1); bitmap_ior (header, header, extended_rgn_header); sbitmap_free (extended_rgn_header); extend_rgns (degree, &idx, header, max_hdr); } } /* Any block that did not end up in a region is placed into a region by itself. */ FOR_EACH_BB_FN (bb, cfun) if (degree[bb->index] >= 0) { rgn_bb_table[idx] = bb->index; RGN_NR_BLOCKS (nr_regions) = 1; RGN_BLOCKS (nr_regions) = idx++; RGN_DONT_CALC_DEPS (nr_regions) = 0; RGN_HAS_REAL_EBB (nr_regions) = 0; CONTAINING_RGN (bb->index) = nr_regions++; BLOCK_TO_BB (bb->index) = 0; } free (max_hdr); free (degree); free (stack); } /* Wrapper function. If FLAG_SEL_SCHED_PIPELINING is set, then use custom function to form regions. Otherwise just call find_rgns_haifa. */ static void find_rgns (void) { if (sel_sched_p () && flag_sel_sched_pipelining) sel_find_rgns (); else haifa_find_rgns (); } static int gather_region_statistics (int **); static void print_region_statistics (int *, int, int *, int); /* Calculate the histogram that shows the number of regions having the given number of basic blocks, and store it in the RSP array. Return the size of this array. */ static int gather_region_statistics (int **rsp) { int i, *a = 0, a_sz = 0; /* a[i] is the number of regions that have (i + 1) basic blocks. */ for (i = 0; i < nr_regions; i++) { int nr_blocks = RGN_NR_BLOCKS (i); gcc_assert (nr_blocks >= 1); if (nr_blocks > a_sz) { a = XRESIZEVEC (int, a, nr_blocks); do a[a_sz++] = 0; while (a_sz != nr_blocks); } a[nr_blocks - 1]++; } *rsp = a; return a_sz; } /* Print regions statistics. S1 and S2 denote the data before and after calling extend_rgns, respectively. */ static void print_region_statistics (int *s1, int s1_sz, int *s2, int s2_sz) { int i; /* We iterate until s2_sz because extend_rgns does not decrease the maximal region size. */ for (i = 1; i < s2_sz; i++) { int n1, n2; n2 = s2[i]; if (n2 == 0) continue; if (i >= s1_sz) n1 = 0; else n1 = s1[i]; fprintf (sched_dump, ";; Region extension statistics: size %d: " \ "was %d + %d more\n", i + 1, n1, n2 - n1); } } /* Extend regions. DEGREE - Array of incoming edge count, considering only the edges, that don't have their sources in formed regions yet. IDXP - pointer to the next available index in rgn_bb_table. HEADER - set of all region heads. LOOP_HDR - mapping from block to the containing loop (two blocks can reside within one region if they have the same loop header). */ void extend_rgns (int *degree, int *idxp, sbitmap header, int *loop_hdr) { int *order, i, idx = *idxp, iter = 0, max_iter, *max_hdr; int nblocks = n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; bool rescan = false; max_iter = param_max_sched_extend_regions_iters; max_hdr = XNEWVEC (int, last_basic_block_for_fn (cfun)); order = XNEWVEC (int, last_basic_block_for_fn (cfun)); post_order_compute (order, false, false); for (i = nblocks - 1; i >= 0; i--) { int bbn = order[i]; if (degree[bbn] >= 0) { max_hdr[bbn] = bbn; rescan = true; } else /* This block already was processed in find_rgns. */ max_hdr[bbn] = -1; } /* The idea is to topologically walk through CFG in top-down order. During the traversal, if all the predecessors of a node are marked to be in the same region (they all have the same max_hdr), then current node is also marked to be a part of that region. Otherwise the node starts its own region. CFG should be traversed until no further changes are made. On each iteration the set of the region heads is extended (the set of those blocks that have max_hdr[bbi] == bbi). This set is upper bounded by the set of all basic blocks, thus the algorithm is guaranteed to terminate. */ while (rescan && iter < max_iter) { rescan = false; for (i = nblocks - 1; i >= 0; i--) { edge e; edge_iterator ei; int bbn = order[i]; if (max_hdr[bbn] != -1 && !bitmap_bit_p (header, bbn)) { int hdr = -1; FOR_EACH_EDGE (e, ei, BASIC_BLOCK_FOR_FN (cfun, bbn)->preds) { int predn = e->src->index; if (predn != ENTRY_BLOCK /* If pred wasn't processed in find_rgns. */ && max_hdr[predn] != -1 /* And pred and bb reside in the same loop. (Or out of any loop). */ && loop_hdr[bbn] == loop_hdr[predn]) { if (hdr == -1) /* Then bb extends the containing region of pred. */ hdr = max_hdr[predn]; else if (hdr != max_hdr[predn]) /* Too bad, there are at least two predecessors that reside in different regions. Thus, BB should begin its own region. */ { hdr = bbn; break; } } else /* BB starts its own region. */ { hdr = bbn; break; } } if (hdr == bbn) { /* If BB start its own region, update set of headers with BB. */ bitmap_set_bit (header, bbn); rescan = true; } else gcc_assert (hdr != -1); max_hdr[bbn] = hdr; } } iter++; } /* Statistics were gathered on the SPEC2000 package of tests with mainline weekly snapshot gcc-4.1-20051015 on ia64. Statistics for SPECint: 1 iteration : 1751 cases (38.7%) 2 iterations: 2770 cases (61.3%) Blocks wrapped in regions by find_rgns without extension: 18295 blocks Blocks wrapped in regions by 2 iterations in extend_rgns: 23821 blocks (We don't count single block regions here). Statistics for SPECfp: 1 iteration : 621 cases (35.9%) 2 iterations: 1110 cases (64.1%) Blocks wrapped in regions by find_rgns without extension: 6476 blocks Blocks wrapped in regions by 2 iterations in extend_rgns: 11155 blocks (We don't count single block regions here). By default we do at most 2 iterations. This can be overridden with max-sched-extend-regions-iters parameter: 0 - disable region extension, N > 0 - do at most N iterations. */ if (sched_verbose && iter != 0) fprintf (sched_dump, ";; Region extension iterations: %d%s\n", iter, rescan ? "... failed" : ""); if (!rescan && iter != 0) { int *s1 = NULL, s1_sz = 0; /* Save the old statistics for later printout. */ if (sched_verbose >= 6) s1_sz = gather_region_statistics (&s1); /* We have succeeded. Now assemble the regions. */ for (i = nblocks - 1; i >= 0; i--) { int bbn = order[i]; if (max_hdr[bbn] == bbn) /* BBN is a region head. */ { edge e; edge_iterator ei; int num_bbs = 0, j, num_insns = 0, large; large = too_large (bbn, &num_bbs, &num_insns); degree[bbn] = -1; rgn_bb_table[idx] = bbn; RGN_BLOCKS (nr_regions) = idx++; RGN_DONT_CALC_DEPS (nr_regions) = 0; RGN_HAS_REAL_EBB (nr_regions) = 0; CONTAINING_RGN (bbn) = nr_regions; BLOCK_TO_BB (bbn) = 0; FOR_EACH_EDGE (e, ei, BASIC_BLOCK_FOR_FN (cfun, bbn)->succs) if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) degree[e->dest->index]--; if (!large) /* Here we check whether the region is too_large. */ for (j = i - 1; j >= 0; j--) { int succn = order[j]; if (max_hdr[succn] == bbn) { if ((large = too_large (succn, &num_bbs, &num_insns))) break; } } if (large) /* If the region is too_large, then wrap every block of the region into single block region. Here we wrap region head only. Other blocks are processed in the below cycle. */ { RGN_NR_BLOCKS (nr_regions) = 1; nr_regions++; } num_bbs = 1; for (j = i - 1; j >= 0; j--) { int succn = order[j]; if (max_hdr[succn] == bbn) /* This cycle iterates over all basic blocks, that are supposed to be in the region with head BBN, and wraps them into that region (or in single block region). */ { gcc_assert (degree[succn] == 0); degree[succn] = -1; rgn_bb_table[idx] = succn; BLOCK_TO_BB (succn) = large ? 0 : num_bbs++; CONTAINING_RGN (succn) = nr_regions; if (large) /* Wrap SUCCN into single block region. */ { RGN_BLOCKS (nr_regions) = idx; RGN_NR_BLOCKS (nr_regions) = 1; RGN_DONT_CALC_DEPS (nr_regions) = 0; RGN_HAS_REAL_EBB (nr_regions) = 0; nr_regions++; } idx++; FOR_EACH_EDGE (e, ei, BASIC_BLOCK_FOR_FN (cfun, succn)->succs) if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) degree[e->dest->index]--; } } if (!large) { RGN_NR_BLOCKS (nr_regions) = num_bbs; nr_regions++; } } } if (sched_verbose >= 6) { int *s2, s2_sz; /* Get the new statistics and print the comparison with the one before calling this function. */ s2_sz = gather_region_statistics (&s2); print_region_statistics (s1, s1_sz, s2, s2_sz); free (s1); free (s2); } } free (order); free (max_hdr); *idxp = idx; } /* Functions for regions scheduling information. */ /* Compute dominators, probability, and potential-split-edges of bb. Assume that these values were already computed for bb's predecessors. */ static void compute_dom_prob_ps (int bb) { edge_iterator in_ei; edge in_edge; /* We shouldn't have any real ebbs yet. */ gcc_assert (ebb_head [bb] == bb + current_blocks); if (IS_RGN_ENTRY (bb)) { bitmap_set_bit (dom[bb], 0); prob[bb] = REG_BR_PROB_BASE; return; } prob[bb] = 0; /* Initialize dom[bb] to '111..1'. */ bitmap_ones (dom[bb]); FOR_EACH_EDGE (in_edge, in_ei, BASIC_BLOCK_FOR_FN (cfun, BB_TO_BLOCK (bb))->preds) { int pred_bb; edge out_edge; edge_iterator out_ei; if (in_edge->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) continue; pred_bb = BLOCK_TO_BB (in_edge->src->index); bitmap_and (dom[bb], dom[bb], dom[pred_bb]); bitmap_ior (ancestor_edges[bb], ancestor_edges[bb], ancestor_edges[pred_bb]); bitmap_set_bit (ancestor_edges[bb], EDGE_TO_BIT (in_edge)); bitmap_ior (pot_split[bb], pot_split[bb], pot_split[pred_bb]); FOR_EACH_EDGE (out_edge, out_ei, in_edge->src->succs) bitmap_set_bit (pot_split[bb], EDGE_TO_BIT (out_edge)); prob[bb] += combine_probabilities (prob[pred_bb], in_edge->probability.initialized_p () ? in_edge->probability.to_reg_br_prob_base () : 0); // The rounding divide in combine_probabilities can result in an extra // probability increment propagating along 50-50 edges. Eventually when // the edges re-merge, the accumulated probability can go slightly above // REG_BR_PROB_BASE. if (prob[bb] > REG_BR_PROB_BASE) prob[bb] = REG_BR_PROB_BASE; } bitmap_set_bit (dom[bb], bb); bitmap_and_compl (pot_split[bb], pot_split[bb], ancestor_edges[bb]); if (sched_verbose >= 2) fprintf (sched_dump, ";; bb_prob(%d, %d) = %3d\n", bb, BB_TO_BLOCK (bb), (100 * prob[bb]) / REG_BR_PROB_BASE); } /* Functions for target info. */ /* Compute in BL the list of split-edges of bb_src relatively to bb_trg. Note that bb_trg dominates bb_src. */ static void split_edges (int bb_src, int bb_trg, edgelst *bl) { auto_sbitmap src (SBITMAP_SIZE (pot_split[bb_src])); bitmap_copy (src, pot_split[bb_src]); bitmap_and_compl (src, src, pot_split[bb_trg]); extract_edgelst (src, bl); } /* Find the valid candidate-source-blocks for the target block TRG, compute their probability, and check if they are speculative or not. For speculative sources, compute their update-blocks and split-blocks. */ static void compute_trg_info (int trg) { candidate *sp; edgelst el = { NULL, 0 }; int i, j, k, update_idx; basic_block block; edge_iterator ei; edge e; candidate_table = XNEWVEC (candidate, current_nr_blocks); bblst_last = 0; /* bblst_table holds split blocks and update blocks for each block after the current one in the region. split blocks and update blocks are the TO blocks of region edges, so there can be at most rgn_nr_edges of them. */ bblst_size = (current_nr_blocks - target_bb) * rgn_nr_edges; bblst_table = XNEWVEC (basic_block, bblst_size); edgelst_last = 0; edgelst_table = XNEWVEC (edge, rgn_nr_edges); /* Define some of the fields for the target bb as well. */ sp = candidate_table + trg; sp->is_valid = 1; sp->is_speculative = 0; sp->src_prob = REG_BR_PROB_BASE; auto_sbitmap visited (last_basic_block_for_fn (cfun)); for (i = trg + 1; i < current_nr_blocks; i++) { sp = candidate_table + i; sp->is_valid = IS_DOMINATED (i, trg); if (sp->is_valid) { int tf = prob[trg], cf = prob[i]; /* In CFGs with low probability edges TF can possibly be zero. */ sp->src_prob = (tf ? GCOV_COMPUTE_SCALE (cf, tf) : 0); sp->is_valid = (sp->src_prob >= min_spec_prob); } if (sp->is_valid) { split_edges (i, trg, &el); sp->is_speculative = (el.nr_members) ? 1 : 0; if (sp->is_speculative && !flag_schedule_speculative) sp->is_valid = 0; } if (sp->is_valid) { /* Compute split blocks and store them in bblst_table. The TO block of every split edge is a split block. */ sp->split_bbs.first_member = &bblst_table[bblst_last]; sp->split_bbs.nr_members = el.nr_members; for (j = 0; j < el.nr_members; bblst_last++, j++) bblst_table[bblst_last] = el.first_member[j]->dest; sp->update_bbs.first_member = &bblst_table[bblst_last]; /* Compute update blocks and store them in bblst_table. For every split edge, look at the FROM block, and check all out edges. For each out edge that is not a split edge, add the TO block to the update block list. This list can end up with a lot of duplicates. We need to weed them out to avoid overrunning the end of the bblst_table. */ update_idx = 0; bitmap_clear (visited); for (j = 0; j < el.nr_members; j++) { block = el.first_member[j]->src; FOR_EACH_EDGE (e, ei, block->succs) { if (!bitmap_bit_p (visited, e->dest->index)) { for (k = 0; k < el.nr_members; k++) if (e == el.first_member[k]) break; if (k >= el.nr_members) { bblst_table[bblst_last++] = e->dest; bitmap_set_bit (visited, e->dest->index); update_idx++; } } } } sp->update_bbs.nr_members = update_idx; /* Make sure we didn't overrun the end of bblst_table. */ gcc_assert (bblst_last <= bblst_size); } else { sp->split_bbs.nr_members = sp->update_bbs.nr_members = 0; sp->is_speculative = 0; sp->src_prob = 0; } } } /* Free the computed target info. */ static void free_trg_info (void) { free (candidate_table); free (bblst_table); free (edgelst_table); } /* Print candidates info, for debugging purposes. Callable from debugger. */ DEBUG_FUNCTION void debug_candidate (int i) { if (!candidate_table[i].is_valid) return; if (candidate_table[i].is_speculative) { int j; fprintf (sched_dump, "src b %d bb %d speculative \n", BB_TO_BLOCK (i), i); fprintf (sched_dump, "split path: "); for (j = 0; j < candidate_table[i].split_bbs.nr_members; j++) { int b = candidate_table[i].split_bbs.first_member[j]->index; fprintf (sched_dump, " %d ", b); } fprintf (sched_dump, "\n"); fprintf (sched_dump, "update path: "); for (j = 0; j < candidate_table[i].update_bbs.nr_members; j++) { int b = candidate_table[i].update_bbs.first_member[j]->index; fprintf (sched_dump, " %d ", b); } fprintf (sched_dump, "\n"); } else { fprintf (sched_dump, " src %d equivalent\n", BB_TO_BLOCK (i)); } } /* Print candidates info, for debugging purposes. Callable from debugger. */ DEBUG_FUNCTION void debug_candidates (int trg) { int i; fprintf (sched_dump, "----------- candidate table: target: b=%d bb=%d ---\n", BB_TO_BLOCK (trg), trg); for (i = trg + 1; i < current_nr_blocks; i++) debug_candidate (i); } /* Functions for speculative scheduling. */ static bitmap_head not_in_df; /* Return false if x is a set of a register alive in the beginning of one of the split-blocks of src, otherwise return true. */ static bool check_live_1 (int src, rtx x) { int i; int regno; rtx reg = SET_DEST (x); if (reg == 0) return true; while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT || GET_CODE (reg) == STRICT_LOW_PART) reg = XEXP (reg, 0); if (GET_CODE (reg) == PARALLEL) { int i; for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) if (XEXP (XVECEXP (reg, 0, i), 0) != 0) if (check_live_1 (src, XEXP (XVECEXP (reg, 0, i), 0))) return true; return false; } if (!REG_P (reg)) return true; regno = REGNO (reg); if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) { /* Global registers are assumed live. */ return false; } else { if (regno < FIRST_PSEUDO_REGISTER) { /* Check for hard registers. */ int j = REG_NREGS (reg); while (--j >= 0) { for (i = 0; i < candidate_table[src].split_bbs.nr_members; i++) { basic_block b = candidate_table[src].split_bbs.first_member[i]; int t = bitmap_bit_p (¬_in_df, b->index); /* We can have split blocks, that were recently generated. Such blocks are always outside current region. */ gcc_assert (!t || (CONTAINING_RGN (b->index) != CONTAINING_RGN (BB_TO_BLOCK (src)))); if (t || REGNO_REG_SET_P (df_get_live_in (b), regno + j)) return false; } } } else { /* Check for pseudo registers. */ for (i = 0; i < candidate_table[src].split_bbs.nr_members; i++) { basic_block b = candidate_table[src].split_bbs.first_member[i]; int t = bitmap_bit_p (¬_in_df, b->index); gcc_assert (!t || (CONTAINING_RGN (b->index) != CONTAINING_RGN (BB_TO_BLOCK (src)))); if (t || REGNO_REG_SET_P (df_get_live_in (b), regno)) return false; } } } return true; } /* If x is a set of a register R, mark that R is alive in the beginning of every update-block of src. */ static void update_live_1 (int src, rtx x) { int i; int regno; rtx reg = SET_DEST (x); if (reg == 0) return; while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT || GET_CODE (reg) == STRICT_LOW_PART) reg = XEXP (reg, 0); if (GET_CODE (reg) == PARALLEL) { int i; for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) if (XEXP (XVECEXP (reg, 0, i), 0) != 0) update_live_1 (src, XEXP (XVECEXP (reg, 0, i), 0)); return; } if (!REG_P (reg)) return; /* Global registers are always live, so the code below does not apply to them. */ regno = REGNO (reg); if (! HARD_REGISTER_NUM_P (regno) || !global_regs[regno]) { for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++) { basic_block b = candidate_table[src].update_bbs.first_member[i]; bitmap_set_range (df_get_live_in (b), regno, REG_NREGS (reg)); } } } /* Return true if insn can be speculatively moved from block src to trg, otherwise return false. Called before first insertion of insn to ready-list or before the scheduling. */ static bool check_live (rtx_insn *insn, int src) { /* Find the registers set by instruction. */ if (GET_CODE (PATTERN (insn)) == SET || GET_CODE (PATTERN (insn)) == CLOBBER) return check_live_1 (src, PATTERN (insn)); else if (GET_CODE (PATTERN (insn)) == PARALLEL) { int j; for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) if ((GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) && !check_live_1 (src, XVECEXP (PATTERN (insn), 0, j))) return false; return true; } return true; } /* Update the live registers info after insn was moved speculatively from block src to trg. */ static void update_live (rtx_insn *insn, int src) { /* Find the registers set by instruction. */ if (GET_CODE (PATTERN (insn)) == SET || GET_CODE (PATTERN (insn)) == CLOBBER) update_live_1 (src, PATTERN (insn)); else if (GET_CODE (PATTERN (insn)) == PARALLEL) { int j; for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) update_live_1 (src, XVECEXP (PATTERN (insn), 0, j)); } } /* True if block bb_to is equal to, or reachable from block bb_from. */ #define IS_REACHABLE(bb_from, bb_to) \ (bb_from == bb_to \ || IS_RGN_ENTRY (bb_from) \ || (bitmap_bit_p \ (ancestor_edges[bb_to], \ EDGE_TO_BIT (single_pred_edge \ (BASIC_BLOCK_FOR_FN (cfun, \ BB_TO_BLOCK (bb_from))))))) /* Turns on the fed_by_spec_load flag for insns fed by load_insn. */ static void set_spec_fed (rtx load_insn) { sd_iterator_def sd_it; dep_t dep; FOR_EACH_DEP (load_insn, SD_LIST_FORW, sd_it, dep) if (DEP_TYPE (dep) == REG_DEP_TRUE) FED_BY_SPEC_LOAD (DEP_CON (dep)) = 1; } /* On the path from the insn to load_insn_bb, find a conditional branch depending on insn, that guards the speculative load. */ static bool find_conditional_protection (rtx_insn *insn, int load_insn_bb) { sd_iterator_def sd_it; dep_t dep; /* Iterate through DEF-USE forward dependences. */ FOR_EACH_DEP (insn, SD_LIST_FORW, sd_it, dep) { rtx_insn *next = DEP_CON (dep); if ((CONTAINING_RGN (BLOCK_NUM (next)) == CONTAINING_RGN (BB_TO_BLOCK (load_insn_bb))) && IS_REACHABLE (INSN_BB (next), load_insn_bb) && load_insn_bb != INSN_BB (next) && DEP_TYPE (dep) == REG_DEP_TRUE && (JUMP_P (next) || find_conditional_protection (next, load_insn_bb))) return true; } return false; } /* find_conditional_protection */ /* Returns true if the same insn1 that participates in the computation of load_insn's address is feeding a conditional branch that is guarding on load_insn. This is true if we find two DEF-USE chains: insn1 -> ... -> conditional-branch insn1 -> ... -> load_insn, and if a flow path exists: insn1 -> ... -> conditional-branch -> ... -> load_insn, and if insn1 is on the path region-entry -> ... -> bb_trg -> ... load_insn. Locate insn1 by climbing on INSN_BACK_DEPS from load_insn. Locate the branch by following INSN_FORW_DEPS from insn1. */ static bool is_conditionally_protected (rtx load_insn, int bb_src, int bb_trg) { sd_iterator_def sd_it; dep_t dep; FOR_EACH_DEP (load_insn, SD_LIST_BACK, sd_it, dep) { rtx_insn *insn1 = DEP_PRO (dep); /* Must be a DEF-USE dependence upon non-branch. */ if (DEP_TYPE (dep) != REG_DEP_TRUE || JUMP_P (insn1)) continue; /* Must exist a path: region-entry -> ... -> bb_trg -> ... load_insn. */ if (INSN_BB (insn1) == bb_src || (CONTAINING_RGN (BLOCK_NUM (insn1)) != CONTAINING_RGN (BB_TO_BLOCK (bb_src))) || (!IS_REACHABLE (bb_trg, INSN_BB (insn1)) && !IS_REACHABLE (INSN_BB (insn1), bb_trg))) continue; /* Now search for the conditional-branch. */ if (find_conditional_protection (insn1, bb_src)) return true; /* Recursive step: search another insn1, "above" current insn1. */ return is_conditionally_protected (insn1, bb_src, bb_trg); } /* The chain does not exist. */ return false; } /* is_conditionally_protected */ /* Returns true if a clue for "similar load" 'insn2' is found, and hence load_insn can move speculatively from bb_src to bb_trg. All the following must hold: (1) both loads have 1 base register (PFREE_CANDIDATEs). (2) load_insn and load1 have a def-use dependence upon the same insn 'insn1'. (3) either load2 is in bb_trg, or: - there's only one split-block, and - load1 is on the escape path, and From all these we can conclude that the two loads access memory addresses that differ at most by a constant, and hence if moving load_insn would cause an exception, it would have been caused by load2 anyhow. */ static bool is_pfree (rtx load_insn, int bb_src, int bb_trg) { sd_iterator_def back_sd_it; dep_t back_dep; candidate *candp = candidate_table + bb_src; if (candp->split_bbs.nr_members != 1) /* Must have exactly one escape block. */ return false; FOR_EACH_DEP (load_insn, SD_LIST_BACK, back_sd_it, back_dep) { rtx_insn *insn1 = DEP_PRO (back_dep); if (DEP_TYPE (back_dep) == REG_DEP_TRUE) /* Found a DEF-USE dependence (insn1, load_insn). */ { sd_iterator_def fore_sd_it; dep_t fore_dep; FOR_EACH_DEP (insn1, SD_LIST_FORW, fore_sd_it, fore_dep) { rtx_insn *insn2 = DEP_CON (fore_dep); if (DEP_TYPE (fore_dep) == REG_DEP_TRUE) { /* Found a DEF-USE dependence (insn1, insn2). */ if (haifa_classify_insn (insn2) != PFREE_CANDIDATE) /* insn2 not guaranteed to be a 1 base reg load. */ continue; if (INSN_BB (insn2) == bb_trg) /* insn2 is the similar load, in the target block. */ return true; if (*(candp->split_bbs.first_member) == BLOCK_FOR_INSN (insn2)) /* insn2 is a similar load, in a split-block. */ return true; } } } } /* Couldn't find a similar load. */ return false; } /* is_pfree */ /* Return true if load_insn is prisky (i.e. if load_insn is fed by a load moved speculatively, or if load_insn is protected by a compare on load_insn's address). */ static bool is_prisky (rtx load_insn, int bb_src, int bb_trg) { if (FED_BY_SPEC_LOAD (load_insn)) return true; if (sd_lists_empty_p (load_insn, SD_LIST_BACK)) /* Dependence may 'hide' out of the region. */ return true; if (is_conditionally_protected (load_insn, bb_src, bb_trg)) return true; return false; } /* Insn is a candidate to be moved speculatively from bb_src to bb_trg. Return true if insn is exception-free (and the motion is valid) and false otherwise. */ static bool is_exception_free (rtx_insn *insn, int bb_src, int bb_trg) { int insn_class = haifa_classify_insn (insn); /* Handle non-load insns. */ switch (insn_class) { case TRAP_FREE: return true; case TRAP_RISKY: return false; default:; } /* Handle loads. */ if (!flag_schedule_speculative_load) return false; IS_LOAD_INSN (insn) = 1; switch (insn_class) { case IFREE: return true; case IRISKY: return false; case PFREE_CANDIDATE: if (is_pfree (insn, bb_src, bb_trg)) return true; /* Don't 'break' here: PFREE-candidate is also PRISKY-candidate. */ /* FALLTHRU */ case PRISKY_CANDIDATE: if (!flag_schedule_speculative_load_dangerous || is_prisky (insn, bb_src, bb_trg)) return false; break; default:; } return flag_schedule_speculative_load_dangerous; } /* The number of insns from the current block scheduled so far. */ static int sched_target_n_insns; /* The number of insns from the current block to be scheduled in total. */ static int target_n_insns; /* The number of insns from the entire region scheduled so far. */ static int sched_n_insns; /* Implementations of the sched_info functions for region scheduling. */ static void init_ready_list (void); static bool can_schedule_ready_p (rtx_insn *); static void begin_schedule_ready (rtx_insn *); static ds_t new_ready (rtx_insn *, ds_t); static bool schedule_more_p (void); static const char *rgn_print_insn (const rtx_insn *, int); static int rgn_rank (rtx_insn *, rtx_insn *); static void compute_jump_reg_dependencies (rtx, regset); /* Functions for speculative scheduling. */ static void rgn_add_remove_insn (rtx_insn *, int); static void rgn_add_block (basic_block, basic_block); static void rgn_fix_recovery_cfg (int, int, int); static basic_block advance_target_bb (basic_block, rtx_insn *); /* Return true if there are more insns that should be scheduled. */ static bool schedule_more_p (void) { return sched_target_n_insns < target_n_insns; } /* Add all insns that are initially ready to the ready list READY. Called once before scheduling a set of insns. */ static void init_ready_list (void) { rtx_insn *prev_head = current_sched_info->prev_head; rtx_insn *next_tail = current_sched_info->next_tail; int bb_src; rtx_insn *insn; target_n_insns = 0; sched_target_n_insns = 0; sched_n_insns = 0; /* Print debugging information. */ if (sched_verbose >= 5) debug_rgn_dependencies (target_bb); /* Prepare current target block info. */ if (current_nr_blocks > 1) compute_trg_info (target_bb); /* Initialize ready list with all 'ready' insns in target block. Count number of insns in the target block being scheduled. */ for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn)) { gcc_assert (TODO_SPEC (insn) == HARD_DEP || TODO_SPEC (insn) == DEP_POSTPONED); TODO_SPEC (insn) = HARD_DEP; try_ready (insn); target_n_insns++; gcc_assert (!(TODO_SPEC (insn) & BEGIN_CONTROL)); } /* Add to ready list all 'ready' insns in valid source blocks. For speculative insns, check-live, exception-free, and issue-delay. */ for (bb_src = target_bb + 1; bb_src < current_nr_blocks; bb_src++) if (IS_VALID (bb_src)) { rtx_insn *src_head; rtx_insn *src_next_tail; rtx_insn *tail, *head; get_ebb_head_tail (EBB_FIRST_BB (bb_src), EBB_LAST_BB (bb_src), &head, &tail); src_next_tail = NEXT_INSN (tail); src_head = head; for (insn = src_head; insn != src_next_tail; insn = NEXT_INSN (insn)) if (INSN_P (insn)) { gcc_assert (TODO_SPEC (insn) == HARD_DEP || TODO_SPEC (insn) == DEP_POSTPONED); TODO_SPEC (insn) = HARD_DEP; try_ready (insn); } } } /* Called after taking INSN from the ready list. Returns true if this insn can be scheduled, nonzero if we should silently discard it. */ static bool can_schedule_ready_p (rtx_insn *insn) { /* An interblock motion? */ if (INSN_BB (insn) != target_bb && IS_SPECULATIVE_INSN (insn)) { /* Cannot schedule this insn unless all operands are live. */ if (!check_live (insn, INSN_BB (insn))) return false; /* Should not move expensive instructions speculatively. */ if (GET_CODE (PATTERN (insn)) != CLOBBER && !targetm.sched.can_speculate_insn (insn)) return false; } return true; } /* Updates counter and other information. Split from can_schedule_ready_p () because when we schedule insn speculatively then insn passed to can_schedule_ready_p () differs from the one passed to begin_schedule_ready (). */ static void begin_schedule_ready (rtx_insn *insn) { /* An interblock motion? */ if (INSN_BB (insn) != target_bb) { if (IS_SPECULATIVE_INSN (insn)) { gcc_assert (check_live (insn, INSN_BB (insn))); update_live (insn, INSN_BB (insn)); /* For speculative load, mark insns fed by it. */ if (IS_LOAD_INSN (insn) || FED_BY_SPEC_LOAD (insn)) set_spec_fed (insn); nr_spec++; } nr_inter++; } else { /* In block motion. */ sched_target_n_insns++; } sched_n_insns++; } /* Called after INSN has all its hard dependencies resolved and the speculation of type TS is enough to overcome them all. Return nonzero if it should be moved to the ready list or the queue, or zero if we should silently discard it. */ static ds_t new_ready (rtx_insn *next, ds_t ts) { if (INSN_BB (next) != target_bb) { int not_ex_free = 0; /* For speculative insns, before inserting to ready/queue, check live, exception-free, and issue-delay. */ if (!IS_VALID (INSN_BB (next)) || CANT_MOVE (next) || (IS_SPECULATIVE_INSN (next) && ((recog_memoized (next) >= 0 && min_insn_conflict_delay (curr_state, next, next) > param_max_sched_insn_conflict_delay) || IS_SPECULATION_CHECK_P (next) || !check_live (next, INSN_BB (next)) || (not_ex_free = !is_exception_free (next, INSN_BB (next), target_bb))))) { if (not_ex_free /* We are here because is_exception_free () == false. But we possibly can handle that with control speculation. */ && sched_deps_info->generate_spec_deps && spec_info->mask & BEGIN_CONTROL) { ds_t new_ds; /* Add control speculation to NEXT's dependency type. */ new_ds = set_dep_weak (ts, BEGIN_CONTROL, MAX_DEP_WEAK); /* Check if NEXT can be speculated with new dependency type. */ if (sched_insn_is_legitimate_for_speculation_p (next, new_ds)) /* Here we got new control-speculative instruction. */ ts = new_ds; else /* NEXT isn't ready yet. */ ts = DEP_POSTPONED; } else /* NEXT isn't ready yet. */ ts = DEP_POSTPONED; } } return ts; } /* Return a string that contains the insn uid and optionally anything else necessary to identify this insn in an output. It's valid to use a static buffer for this. The ALIGNED parameter should cause the string to be formatted so that multiple output lines will line up nicely. */ static const char * rgn_print_insn (const rtx_insn *insn, int aligned) { static char tmp[80]; if (aligned) sprintf (tmp, "b%3d: i%4d", INSN_BB (insn), INSN_UID (insn)); else { if (current_nr_blocks > 1 && INSN_BB (insn) != target_bb) sprintf (tmp, "%d/b%d", INSN_UID (insn), INSN_BB (insn)); else sprintf (tmp, "%d", INSN_UID (insn)); } return tmp; } /* Compare priority of two insns. Return a positive number if the second insn is to be preferred for scheduling, and a negative one if the first is to be preferred. Zero if they are equally good. */ static int rgn_rank (rtx_insn *insn1, rtx_insn *insn2) { /* Some comparison make sense in interblock scheduling only. */ if (INSN_BB (insn1) != INSN_BB (insn2)) { int spec_val, prob_val; /* Prefer an inblock motion on an interblock motion. */ if ((INSN_BB (insn2) == target_bb) && (INSN_BB (insn1) != target_bb)) return 1; if ((INSN_BB (insn1) == target_bb) && (INSN_BB (insn2) != target_bb)) return -1; /* Prefer a useful motion on a speculative one. */ spec_val = IS_SPECULATIVE_INSN (insn1) - IS_SPECULATIVE_INSN (insn2); if (spec_val) return spec_val; /* Prefer a more probable (speculative) insn. */ prob_val = INSN_PROBABILITY (insn2) - INSN_PROBABILITY (insn1); if (prob_val) return prob_val; } return 0; } /* NEXT is an instruction that depends on INSN (a backward dependence); return true if we should include this dependence in priority calculations. */ bool contributes_to_priority (rtx_insn *next, rtx_insn *insn) { /* NEXT and INSN reside in one ebb. */ return BLOCK_TO_BB (BLOCK_NUM (next)) == BLOCK_TO_BB (BLOCK_NUM (insn)); } /* INSN is a JUMP_INSN. Store the set of registers that must be considered as used by this jump in USED. */ static void compute_jump_reg_dependencies (rtx insn ATTRIBUTE_UNUSED, regset used ATTRIBUTE_UNUSED) { /* Nothing to do here, since we postprocess jumps in add_branch_dependences. */ } /* This variable holds common_sched_info hooks and data relevant to the interblock scheduler. */ static struct common_sched_info_def rgn_common_sched_info; /* This holds data for the dependence analysis relevant to the interblock scheduler. */ static struct sched_deps_info_def rgn_sched_deps_info; /* This holds constant data used for initializing the above structure for the Haifa scheduler. */ static const struct sched_deps_info_def rgn_const_sched_deps_info = { compute_jump_reg_dependencies, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 0, 0, 0 }; /* Same as above, but for the selective scheduler. */ static const struct sched_deps_info_def rgn_const_sel_sched_deps_info = { compute_jump_reg_dependencies, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 0, 0, 0 }; /* Return true if scheduling INSN will trigger finish of scheduling current block. */ static bool rgn_insn_finishes_block_p (rtx_insn *insn) { if (INSN_BB (insn) == target_bb && sched_target_n_insns + 1 == target_n_insns) /* INSN is the last not-scheduled instruction in the current block. */ return true; return false; } /* Used in schedule_insns to initialize current_sched_info for scheduling regions (or single basic blocks). */ static const struct haifa_sched_info rgn_const_sched_info = { init_ready_list, can_schedule_ready_p, schedule_more_p, new_ready, rgn_rank, rgn_print_insn, contributes_to_priority, rgn_insn_finishes_block_p, NULL, NULL, NULL, NULL, 0, 0, rgn_add_remove_insn, begin_schedule_ready, NULL, advance_target_bb, NULL, NULL, SCHED_RGN }; /* This variable holds the data and hooks needed to the Haifa scheduler backend for the interblock scheduler frontend. */ static struct haifa_sched_info rgn_sched_info; /* Returns maximum priority that an insn was assigned to. */ int get_rgn_sched_max_insns_priority (void) { return rgn_sched_info.sched_max_insns_priority; } /* Determine if PAT sets a TARGET_CLASS_LIKELY_SPILLED_P register. */ static bool sets_likely_spilled (rtx pat) { bool ret = false; note_pattern_stores (pat, sets_likely_spilled_1, &ret); return ret; } static void sets_likely_spilled_1 (rtx x, const_rtx pat, void *data) { bool *ret = (bool *) data; if (GET_CODE (pat) == SET && REG_P (x) && HARD_REGISTER_P (x) && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x)))) *ret = true; } /* A bitmap to note insns that participate in any dependency. Used in add_branch_dependences. */ static sbitmap insn_referenced; /* Add dependences so that branches are scheduled to run last in their block. */ static void add_branch_dependences (rtx_insn *head, rtx_insn *tail) { rtx_insn *insn, *last; /* For all branches, calls, uses, clobbers, and instructions that can throw exceptions, force them to remain in order at the end of the block by adding dependencies and giving the last a high priority. There may be notes present, and prev_head may also be a note. Branches must obviously remain at the end. Calls should remain at the end since moving them results in worse register allocation. Uses remain at the end to ensure proper register allocation. Predecessors of SCHED_GROUP_P instructions at the end remain at the end. COND_EXEC insns cannot be moved past a branch (see e.g. PR17808). Insns setting TARGET_CLASS_LIKELY_SPILLED_P registers (usually return values) are not moved before reload because we can wind up with register allocation failures. */ while (tail != head && DEBUG_INSN_P (tail)) tail = PREV_INSN (tail); insn = tail; last = 0; while (CALL_P (insn) || JUMP_P (insn) || JUMP_TABLE_DATA_P (insn) || (NONJUMP_INSN_P (insn) && (GET_CODE (PATTERN (insn)) == USE || GET_CODE (PATTERN (insn)) == CLOBBER || can_throw_internal (insn) || (!reload_completed && sets_likely_spilled (PATTERN (insn))))) || NOTE_P (insn) || (last != 0 && SCHED_GROUP_P (last))) { if (!NOTE_P (insn)) { if (last != 0 && sd_find_dep_between (insn, last, false) == NULL) { if (! sched_insns_conditions_mutex_p (last, insn)) add_dependence (last, insn, REG_DEP_ANTI); bitmap_set_bit (insn_referenced, INSN_LUID (insn)); } CANT_MOVE (insn) = 1; last = insn; } /* Don't overrun the bounds of the basic block. */ if (insn == head) break; do insn = PREV_INSN (insn); while (insn != head && DEBUG_INSN_P (insn)); } /* Selective scheduling handles control dependencies by itself, and CANT_MOVE flags ensure that other insns will be kept in place. */ if (sel_sched_p ()) return; /* Make sure these insns are scheduled last in their block. */ insn = last; if (insn != 0) while (insn != head) { insn = prev_nonnote_insn (insn); if (bitmap_bit_p (insn_referenced, INSN_LUID (insn)) || DEBUG_INSN_P (insn)) continue; if (! sched_insns_conditions_mutex_p (last, insn)) add_dependence (last, insn, REG_DEP_ANTI); } if (!targetm.have_conditional_execution ()) return; /* Finally, if the block ends in a jump, and we are doing intra-block scheduling, make sure that the branch depends on any COND_EXEC insns inside the block to avoid moving the COND_EXECs past the branch insn. We only have to do this after reload, because (1) before reload there are no COND_EXEC insns, and (2) the region scheduler is an intra-block scheduler after reload. FIXME: We could in some cases move COND_EXEC insns past the branch if this scheduler would be a little smarter. Consider this code: T = [addr] C ? addr += 4 !C ? X += 12 C ? T += 1 C ? jump foo On a target with a one cycle stall on a memory access the optimal sequence would be: T = [addr] C ? addr += 4 C ? T += 1 C ? jump foo !C ? X += 12 We don't want to put the 'X += 12' before the branch because it just wastes a cycle of execution time when the branch is taken. Note that in the example "!C" will always be true. That is another possible improvement for handling COND_EXECs in this scheduler: it could remove always-true predicates. */ if (!reload_completed || ! (JUMP_P (tail) || JUMP_TABLE_DATA_P (tail))) return; insn = tail; while (insn != head) { insn = PREV_INSN (insn); /* Note that we want to add this dependency even when sched_insns_conditions_mutex_p returns true. The whole point is that we _want_ this dependency, even if these insns really are independent. */ if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == COND_EXEC) add_dependence (tail, insn, REG_DEP_ANTI); } } /* Data structures for the computation of data dependences in a regions. We keep one `deps' structure for every basic block. Before analyzing the data dependences for a bb, its variables are initialized as a function of the variables of its predecessors. When the analysis for a bb completes, we save the contents to the corresponding bb_deps[bb] variable. */ static class deps_desc *bb_deps; static void concat_insn_mem_list (rtx_insn_list *copy_insns, rtx_expr_list *copy_mems, rtx_insn_list **old_insns_p, rtx_expr_list **old_mems_p) { rtx_insn_list *new_insns = *old_insns_p; rtx_expr_list *new_mems = *old_mems_p; while (copy_insns) { new_insns = alloc_INSN_LIST (copy_insns->insn (), new_insns); new_mems = alloc_EXPR_LIST (VOIDmode, copy_mems->element (), new_mems); copy_insns = copy_insns->next (); copy_mems = copy_mems->next (); } *old_insns_p = new_insns; *old_mems_p = new_mems; } /* Join PRED_DEPS to the SUCC_DEPS. */ void deps_join (class deps_desc *succ_deps, class deps_desc *pred_deps) { unsigned reg; reg_set_iterator rsi; /* The reg_last lists are inherited by successor. */ EXECUTE_IF_SET_IN_REG_SET (&pred_deps->reg_last_in_use, 0, reg, rsi) { struct deps_reg *pred_rl = &pred_deps->reg_last[reg]; struct deps_reg *succ_rl = &succ_deps->reg_last[reg]; succ_rl->uses = concat_INSN_LIST (pred_rl->uses, succ_rl->uses); succ_rl->sets = concat_INSN_LIST (pred_rl->sets, succ_rl->sets); succ_rl->implicit_sets = concat_INSN_LIST (pred_rl->implicit_sets, succ_rl->implicit_sets); succ_rl->clobbers = concat_INSN_LIST (pred_rl->clobbers, succ_rl->clobbers); succ_rl->uses_length += pred_rl->uses_length; succ_rl->clobbers_length += pred_rl->clobbers_length; } IOR_REG_SET (&succ_deps->reg_last_in_use, &pred_deps->reg_last_in_use); /* Mem read/write lists are inherited by successor. */ concat_insn_mem_list (pred_deps->pending_read_insns, pred_deps->pending_read_mems, &succ_deps->pending_read_insns, &succ_deps->pending_read_mems); concat_insn_mem_list (pred_deps->pending_write_insns, pred_deps->pending_write_mems, &succ_deps->pending_write_insns, &succ_deps->pending_write_mems); succ_deps->pending_jump_insns = concat_INSN_LIST (pred_deps->pending_jump_insns, succ_deps->pending_jump_insns); succ_deps->last_pending_memory_flush = concat_INSN_LIST (pred_deps->last_pending_memory_flush, succ_deps->last_pending_memory_flush); succ_deps->pending_read_list_length += pred_deps->pending_read_list_length; succ_deps->pending_write_list_length += pred_deps->pending_write_list_length; succ_deps->pending_flush_length += pred_deps->pending_flush_length; /* last_function_call is inherited by successor. */ succ_deps->last_function_call = concat_INSN_LIST (pred_deps->last_function_call, succ_deps->last_function_call); /* last_function_call_may_noreturn is inherited by successor. */ succ_deps->last_function_call_may_noreturn = concat_INSN_LIST (pred_deps->last_function_call_may_noreturn, succ_deps->last_function_call_may_noreturn); /* sched_before_next_call is inherited by successor. */ succ_deps->sched_before_next_call = concat_INSN_LIST (pred_deps->sched_before_next_call, succ_deps->sched_before_next_call); } /* After computing the dependencies for block BB, propagate the dependencies found in TMP_DEPS to the successors of the block. */ static void propagate_deps (int bb, class deps_desc *pred_deps) { basic_block block = BASIC_BLOCK_FOR_FN (cfun, BB_TO_BLOCK (bb)); edge_iterator ei; edge e; /* bb's structures are inherited by its successors. */ FOR_EACH_EDGE (e, ei, block->succs) { /* Only bbs "below" bb, in the same region, are interesting. */ if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) || CONTAINING_RGN (block->index) != CONTAINING_RGN (e->dest->index) || BLOCK_TO_BB (e->dest->index) <= bb) continue; deps_join (bb_deps + BLOCK_TO_BB (e->dest->index), pred_deps); } /* These lists should point to the right place, for correct freeing later. */ bb_deps[bb].pending_read_insns = pred_deps->pending_read_insns; bb_deps[bb].pending_read_mems = pred_deps->pending_read_mems; bb_deps[bb].pending_write_insns = pred_deps->pending_write_insns; bb_deps[bb].pending_write_mems = pred_deps->pending_write_mems; bb_deps[bb].pending_jump_insns = pred_deps->pending_jump_insns; /* Can't allow these to be freed twice. */ pred_deps->pending_read_insns = 0; pred_deps->pending_read_mems = 0; pred_deps->pending_write_insns = 0; pred_deps->pending_write_mems = 0; pred_deps->pending_jump_insns = 0; } /* Compute dependences inside bb. In a multiple blocks region: (1) a bb is analyzed after its predecessors, and (2) the lists in effect at the end of bb (after analyzing for bb) are inherited by bb's successors. Specifically for reg-reg data dependences, the block insns are scanned by sched_analyze () top-to-bottom. Three lists are maintained by sched_analyze (): reg_last[].sets for register DEFs, reg_last[].implicit_sets for implicit hard register DEFs, and reg_last[].uses for register USEs. When analysis is completed for bb, we update for its successors: ; - DEFS[succ] = Union (DEFS [succ], DEFS [bb]) ; - IMPLICIT_DEFS[succ] = Union (IMPLICIT_DEFS [succ], IMPLICIT_DEFS [bb]) ; - USES[succ] = Union (USES [succ], DEFS [bb]) The mechanism for computing mem-mem data dependence is very similar, and the result is interblock dependences in the region. */ static void compute_block_dependences (int bb) { rtx_insn *head, *tail; class deps_desc tmp_deps; tmp_deps = bb_deps[bb]; /* Do the analysis for this block. */ gcc_assert (EBB_FIRST_BB (bb) == EBB_LAST_BB (bb)); get_ebb_head_tail (EBB_FIRST_BB (bb), EBB_LAST_BB (bb), &head, &tail); sched_analyze (&tmp_deps, head, tail); add_branch_dependences (head, tail); if (current_nr_blocks > 1) propagate_deps (bb, &tmp_deps); /* Free up the INSN_LISTs. */ free_deps (&tmp_deps); if (targetm.sched.dependencies_evaluation_hook) targetm.sched.dependencies_evaluation_hook (head, tail); } /* Free dependencies of instructions inside BB. */ static void free_block_dependencies (int bb) { rtx_insn *head; rtx_insn *tail; get_ebb_head_tail (EBB_FIRST_BB (bb), EBB_LAST_BB (bb), &head, &tail); if (no_real_insns_p (head, tail)) return; sched_free_deps (head, tail, true); } /* Remove all INSN_LISTs and EXPR_LISTs from the pending lists and add them to the unused_*_list variables, so that they can be reused. */ static void free_pending_lists (void) { int bb; for (bb = 0; bb < current_nr_blocks; bb++) { free_INSN_LIST_list (&bb_deps[bb].pending_read_insns); free_INSN_LIST_list (&bb_deps[bb].pending_write_insns); free_EXPR_LIST_list (&bb_deps[bb].pending_read_mems); free_EXPR_LIST_list (&bb_deps[bb].pending_write_mems); free_INSN_LIST_list (&bb_deps[bb].pending_jump_insns); } } /* Print dependences for debugging starting from FROM_BB. Callable from debugger. */ /* Print dependences for debugging starting from FROM_BB. Callable from debugger. */ DEBUG_FUNCTION void debug_rgn_dependencies (int from_bb) { int bb; fprintf (sched_dump, ";; --------------- forward dependences: ------------ \n"); for (bb = from_bb; bb < current_nr_blocks; bb++) { rtx_insn *head, *tail; get_ebb_head_tail (EBB_FIRST_BB (bb), EBB_LAST_BB (bb), &head, &tail); fprintf (sched_dump, "\n;; --- Region Dependences --- b %d bb %d \n", BB_TO_BLOCK (bb), bb); debug_dependencies (head, tail); } } /* Print dependencies information for instructions between HEAD and TAIL. ??? This function would probably fit best in haifa-sched.cc. */ void debug_dependencies (rtx_insn *head, rtx_insn *tail) { rtx_insn *insn; rtx_insn *next_tail = NEXT_INSN (tail); fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%14s\n", "insn", "code", "bb", "dep", "prio", "cost", "reservation"); fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%14s\n", "----", "----", "--", "---", "----", "----", "-----------"); for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) { if (! INSN_P (insn)) { int n; fprintf (sched_dump, ";; %6d ", INSN_UID (insn)); if (NOTE_P (insn)) { n = NOTE_KIND (insn); fprintf (sched_dump, "%s\n", GET_NOTE_INSN_NAME (n)); } else fprintf (sched_dump, " {%s}\n", GET_RTX_NAME (GET_CODE (insn))); continue; } fprintf (sched_dump, ";; %s%5d%6d%6d%6d%6d%6d ", (SCHED_GROUP_P (insn) ? "+" : " "), INSN_UID (insn), INSN_CODE (insn), BLOCK_NUM (insn), sched_emulate_haifa_p ? -1 : sd_lists_size (insn, SD_LIST_BACK), (sel_sched_p () ? (sched_emulate_haifa_p ? -1 : INSN_PRIORITY (insn)) : INSN_PRIORITY (insn)), (sel_sched_p () ? (sched_emulate_haifa_p ? -1 : insn_sched_cost (insn)) : insn_sched_cost (insn))); if (recog_memoized (insn) < 0) fprintf (sched_dump, "nothing"); else print_reservation (sched_dump, insn); fprintf (sched_dump, "\t: "); { sd_iterator_def sd_it; dep_t dep; FOR_EACH_DEP (insn, SD_LIST_FORW, sd_it, dep) fprintf (sched_dump, "%d%s%s ", INSN_UID (DEP_CON (dep)), DEP_NONREG (dep) ? "n" : "", DEP_MULTIPLE (dep) ? "m" : ""); } fprintf (sched_dump, "\n"); } fprintf (sched_dump, "\n"); } /* Dump dependency graph for the current region to a file using dot syntax. */ void dump_rgn_dependencies_dot (FILE *file) { rtx_insn *head, *tail, *con, *pro; sd_iterator_def sd_it; dep_t dep; int bb; pretty_printer pp; pp.buffer->stream = file; pp_printf (&pp, "digraph SchedDG {\n"); for (bb = 0; bb < current_nr_blocks; ++bb) { /* Begin subgraph (basic block). */ pp_printf (&pp, "subgraph cluster_block_%d {\n", bb); pp_printf (&pp, "\t" "color=blue;" "\n"); pp_printf (&pp, "\t" "style=bold;" "\n"); pp_printf (&pp, "\t" "label=\"BB #%d\";\n", BB_TO_BLOCK (bb)); /* Setup head and tail (no support for EBBs). */ gcc_assert (EBB_FIRST_BB (bb) == EBB_LAST_BB (bb)); get_ebb_head_tail (EBB_FIRST_BB (bb), EBB_LAST_BB (bb), &head, &tail); tail = NEXT_INSN (tail); /* Dump all insns. */ for (con = head; con != tail; con = NEXT_INSN (con)) { if (!INSN_P (con)) continue; /* Pretty print the insn. */ pp_printf (&pp, "\t%d [label=\"{", INSN_UID (con)); pp_write_text_to_stream (&pp); print_insn (&pp, con, /*verbose=*/false); pp_write_text_as_dot_label_to_stream (&pp, /*for_record=*/true); pp_write_text_to_stream (&pp); /* Dump instruction attributes. */ pp_printf (&pp, "|{ uid:%d | luid:%d | prio:%d }}\",shape=record]\n", INSN_UID (con), INSN_LUID (con), INSN_PRIORITY (con)); /* Dump all deps. */ FOR_EACH_DEP (con, SD_LIST_BACK, sd_it, dep) { int weight = 0; const char *color; pro = DEP_PRO (dep); switch (DEP_TYPE (dep)) { case REG_DEP_TRUE: color = "black"; weight = 1; break; case REG_DEP_OUTPUT: case REG_DEP_ANTI: color = "orange"; break; case REG_DEP_CONTROL: color = "blue"; break; default: gcc_unreachable (); } pp_printf (&pp, "\t%d -> %d [color=%s", INSN_UID (pro), INSN_UID (con), color); if (int cost = dep_cost (dep)) pp_printf (&pp, ",label=%d", cost); pp_printf (&pp, ",weight=%d", weight); pp_printf (&pp, "];\n"); } } pp_printf (&pp, "}\n"); } pp_printf (&pp, "}\n"); pp_flush (&pp); } /* Dump dependency graph for the current region to a file using dot syntax. */ DEBUG_FUNCTION void dump_rgn_dependencies_dot (const char *fname) { FILE *fp; fp = fopen (fname, "w"); if (!fp) { perror ("fopen"); return; } dump_rgn_dependencies_dot (fp); fclose (fp); } /* Returns true if all the basic blocks of the current region have NOTE_DISABLE_SCHED_OF_BLOCK which means not to schedule that region. */ bool sched_is_disabled_for_current_region_p (void) { int bb; for (bb = 0; bb < current_nr_blocks; bb++) if (!(BASIC_BLOCK_FOR_FN (cfun, BB_TO_BLOCK (bb))->flags & BB_DISABLE_SCHEDULE)) return false; return true; } /* Free all region dependencies saved in INSN_BACK_DEPS and INSN_RESOLVED_BACK_DEPS. The Haifa scheduler does this on the fly when scheduling, so this function is supposed to be called from the selective scheduling only. */ void free_rgn_deps (void) { int bb; for (bb = 0; bb < current_nr_blocks; bb++) { rtx_insn *head, *tail; gcc_assert (EBB_FIRST_BB (bb) == EBB_LAST_BB (bb)); get_ebb_head_tail (EBB_FIRST_BB (bb), EBB_LAST_BB (bb), &head, &tail); sched_free_deps (head, tail, false); } } static int rgn_n_insns; /* Compute insn priority for a current region. */ void compute_priorities (void) { int bb; current_sched_info->sched_max_insns_priority = 0; for (bb = 0; bb < current_nr_blocks; bb++) { rtx_insn *head, *tail; gcc_assert (EBB_FIRST_BB (bb) == EBB_LAST_BB (bb)); get_ebb_head_tail (EBB_FIRST_BB (bb), EBB_LAST_BB (bb), &head, &tail); if (no_real_insns_p (head, tail)) continue; rgn_n_insns += set_priorities (head, tail); } current_sched_info->sched_max_insns_priority++; } /* (Re-)initialize the arrays of DFA states at the end of each basic block. SAVED_LAST_BASIC_BLOCK is the previous length of the arrays. It must be zero for the first call to this function, to allocate the arrays for the first time. This function is called once during initialization of the scheduler, and called again to resize the arrays if new basic blocks have been created, for example for speculation recovery code. */ static void realloc_bb_state_array (int saved_last_basic_block) { char *old_bb_state_array = bb_state_array; size_t lbb = (size_t) last_basic_block_for_fn (cfun); size_t slbb = (size_t) saved_last_basic_block; /* Nothing to do if nothing changed since the last time this was called. */ if (saved_last_basic_block == last_basic_block_for_fn (cfun)) return; /* The selective scheduler doesn't use the state arrays. */ if (sel_sched_p ()) { gcc_assert (bb_state_array == NULL && bb_state == NULL); return; } gcc_checking_assert (saved_last_basic_block == 0 || (bb_state_array != NULL && bb_state != NULL)); bb_state_array = XRESIZEVEC (char, bb_state_array, lbb * dfa_state_size); bb_state = XRESIZEVEC (state_t, bb_state, lbb); /* If BB_STATE_ARRAY has moved, fixup all the state pointers array. Otherwise only fixup the newly allocated ones. For the state array itself, only initialize the new entries. */ bool bb_state_array_moved = (bb_state_array != old_bb_state_array); for (size_t i = bb_state_array_moved ? 0 : slbb; i < lbb; i++) bb_state[i] = (state_t) (bb_state_array + i * dfa_state_size); for (size_t i = slbb; i < lbb; i++) state_reset (bb_state[i]); } /* Free the arrays of DFA states at the end of each basic block. */ static void free_bb_state_array (void) { free (bb_state_array); free (bb_state); bb_state_array = NULL; bb_state = NULL; } /* If LAST_BB falls through to another block B, record that B should start with DFA start STATE. */ static void save_state_for_fallthru_edge (basic_block last_bb, state_t state) { edge f = find_fallthru_edge (last_bb->succs); if (f && (!f->probability.initialized_p () || (f->probability.to_reg_br_prob_base () * 100 / REG_BR_PROB_BASE >= param_sched_state_edge_prob_cutoff))) { memcpy (bb_state[f->dest->index], state, dfa_state_size); if (sched_verbose >= 5) fprintf (sched_dump, "saving state for edge %d->%d\n", f->src->index, f->dest->index); } } /* Schedule a region. A region is either an inner loop, a loop-free subroutine, or a single basic block. Each bb in the region is scheduled after its flow predecessors. */ static void schedule_region (int rgn) { int bb; int sched_rgn_n_insns = 0; rgn_n_insns = 0; /* Do not support register pressure sensitive scheduling for the new regions as we don't update the liveness info for them. */ if (sched_pressure != SCHED_PRESSURE_NONE && rgn >= nr_regions_initial) { free_global_sched_pressure_data (); sched_pressure = SCHED_PRESSURE_NONE; } rgn_setup_region (rgn); /* Don't schedule region that is marked by NOTE_DISABLE_SCHED_OF_BLOCK. */ if (sched_is_disabled_for_current_region_p ()) return; sched_rgn_compute_dependencies (rgn); sched_rgn_local_init (rgn); /* Set priorities. */ compute_priorities (); sched_extend_ready_list (rgn_n_insns); if (sched_pressure == SCHED_PRESSURE_WEIGHTED) { sched_init_region_reg_pressure_info (); for (bb = 0; bb < current_nr_blocks; bb++) { basic_block first_bb, last_bb; rtx_insn *head, *tail; first_bb = EBB_FIRST_BB (bb); last_bb = EBB_LAST_BB (bb); get_ebb_head_tail (first_bb, last_bb, &head, &tail); if (no_real_insns_p (head, tail)) { gcc_assert (first_bb == last_bb); continue; } sched_setup_bb_reg_pressure_info (first_bb, PREV_INSN (head)); } } /* Now we can schedule all blocks. */ for (bb = 0; bb < current_nr_blocks; bb++) { basic_block first_bb, last_bb, curr_bb; rtx_insn *head, *tail; first_bb = EBB_FIRST_BB (bb); last_bb = EBB_LAST_BB (bb); get_ebb_head_tail (first_bb, last_bb, &head, &tail); if (no_real_insns_p (head, tail)) { gcc_assert (first_bb == last_bb); save_state_for_fallthru_edge (last_bb, bb_state[first_bb->index]); continue; } current_sched_info->prev_head = PREV_INSN (head); current_sched_info->next_tail = NEXT_INSN (tail); remove_notes (head, tail); unlink_bb_notes (first_bb, last_bb); target_bb = bb; gcc_assert (flag_schedule_interblock || current_nr_blocks == 1); current_sched_info->queue_must_finish_empty = current_nr_blocks == 1; curr_bb = first_bb; int saved_last_basic_block = last_basic_block_for_fn (cfun); schedule_block (&curr_bb, bb_state[first_bb->index]); gcc_assert (EBB_FIRST_BB (bb) == first_bb); sched_rgn_n_insns += sched_n_insns; realloc_bb_state_array (saved_last_basic_block); save_state_for_fallthru_edge (last_bb, curr_state); /* Clean up. */ if (current_nr_blocks > 1) free_trg_info (); } /* Sanity check: verify that all region insns were scheduled. */ gcc_assert (sched_rgn_n_insns == rgn_n_insns); sched_finish_ready_list (); /* Done with this region. */ sched_rgn_local_finish (); /* Free dependencies. */ for (bb = 0; bb < current_nr_blocks; ++bb) free_block_dependencies (bb); gcc_assert (haifa_recovery_bb_ever_added_p || deps_pools_are_empty_p ()); } /* Initialize data structures for region scheduling. */ void sched_rgn_init (bool single_blocks_p) { min_spec_prob = ((param_min_spec_prob * REG_BR_PROB_BASE) / 100); nr_inter = 0; nr_spec = 0; extend_regions (); CONTAINING_RGN (ENTRY_BLOCK) = -1; CONTAINING_RGN (EXIT_BLOCK) = -1; realloc_bb_state_array (0); /* Compute regions for scheduling. */ if (single_blocks_p || n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS + 1 || !flag_schedule_interblock || is_cfg_nonregular ()) { find_single_block_region (sel_sched_p ()); } else { /* Compute the dominators and post dominators. */ if (!sel_sched_p ()) calculate_dominance_info (CDI_DOMINATORS); /* Find regions. */ find_rgns (); if (sched_verbose >= 3) debug_regions (); /* For now. This will move as more and more of haifa is converted to using the cfg code. */ if (!sel_sched_p ()) free_dominance_info (CDI_DOMINATORS); } gcc_assert (nr_regions > 0 && nr_regions <= n_basic_blocks_for_fn (cfun)); RGN_BLOCKS (nr_regions) = (RGN_BLOCKS (nr_regions - 1) + RGN_NR_BLOCKS (nr_regions - 1)); nr_regions_initial = nr_regions; } /* Free data structures for region scheduling. */ void sched_rgn_finish (void) { free_bb_state_array (); /* Reposition the prologue and epilogue notes in case we moved the prologue/epilogue insns. */ if (reload_completed) reposition_prologue_and_epilogue_notes (); if (sched_verbose) { if (reload_completed == 0 && flag_schedule_interblock) { fprintf (sched_dump, "\n;; Procedure interblock/speculative motions == %d/%d \n", nr_inter, nr_spec); } else gcc_assert (nr_inter <= 0); fprintf (sched_dump, "\n\n"); } nr_regions = 0; free (rgn_table); rgn_table = NULL; free (rgn_bb_table); rgn_bb_table = NULL; free (block_to_bb); block_to_bb = NULL; free (containing_rgn); containing_rgn = NULL; free (ebb_head); ebb_head = NULL; } /* Setup global variables like CURRENT_BLOCKS and CURRENT_NR_BLOCK to point to the region RGN. */ void rgn_setup_region (int rgn) { int bb; /* Set variables for the current region. */ current_nr_blocks = RGN_NR_BLOCKS (rgn); current_blocks = RGN_BLOCKS (rgn); /* EBB_HEAD is a region-scope structure. But we realloc it for each region to save time/memory/something else. See comments in add_block1, for what reasons we allocate +1 element. */ ebb_head = XRESIZEVEC (int, ebb_head, current_nr_blocks + 1); for (bb = 0; bb <= current_nr_blocks; bb++) ebb_head[bb] = current_blocks + bb; } /* Compute instruction dependencies in region RGN. */ void sched_rgn_compute_dependencies (int rgn) { if (!RGN_DONT_CALC_DEPS (rgn)) { int bb; if (sel_sched_p ()) sched_emulate_haifa_p = 1; init_deps_global (); /* Initializations for region data dependence analysis. */ bb_deps = XNEWVEC (class deps_desc, current_nr_blocks); for (bb = 0; bb < current_nr_blocks; bb++) init_deps (bb_deps + bb, false); /* Initialize bitmap used in add_branch_dependences. */ insn_referenced = sbitmap_alloc (sched_max_luid); bitmap_clear (insn_referenced); /* Compute backward dependencies. */ for (bb = 0; bb < current_nr_blocks; bb++) compute_block_dependences (bb); sbitmap_free (insn_referenced); free_pending_lists (); finish_deps_global (); free (bb_deps); /* We don't want to recalculate this twice. */ RGN_DONT_CALC_DEPS (rgn) = 1; if (sel_sched_p ()) sched_emulate_haifa_p = 0; } else /* (This is a recovery block. It is always a single block region.) OR (We use selective scheduling.) */ gcc_assert (current_nr_blocks == 1 || sel_sched_p ()); } /* Init region data structures. Returns true if this region should not be scheduled. */ void sched_rgn_local_init (int rgn) { int bb; /* Compute interblock info: probabilities, split-edges, dominators, etc. */ if (current_nr_blocks > 1) { basic_block block; edge e; edge_iterator ei; prob = XNEWVEC (int, current_nr_blocks); dom = sbitmap_vector_alloc (current_nr_blocks, current_nr_blocks); bitmap_vector_clear (dom, current_nr_blocks); /* Use ->aux to implement EDGE_TO_BIT mapping. */ rgn_nr_edges = 0; FOR_EACH_BB_FN (block, cfun) { if (CONTAINING_RGN (block->index) != rgn) continue; FOR_EACH_EDGE (e, ei, block->succs) SET_EDGE_TO_BIT (e, rgn_nr_edges++); } rgn_edges = XNEWVEC (edge, rgn_nr_edges); rgn_nr_edges = 0; FOR_EACH_BB_FN (block, cfun) { if (CONTAINING_RGN (block->index) != rgn) continue; FOR_EACH_EDGE (e, ei, block->succs) rgn_edges[rgn_nr_edges++] = e; } /* Split edges. */ pot_split = sbitmap_vector_alloc (current_nr_blocks, rgn_nr_edges); bitmap_vector_clear (pot_split, current_nr_blocks); ancestor_edges = sbitmap_vector_alloc (current_nr_blocks, rgn_nr_edges); bitmap_vector_clear (ancestor_edges, current_nr_blocks); /* Compute probabilities, dominators, split_edges. */ for (bb = 0; bb < current_nr_blocks; bb++) compute_dom_prob_ps (bb); /* Cleanup ->aux used for EDGE_TO_BIT mapping. */ /* We don't need them anymore. But we want to avoid duplication of aux fields in the newly created edges. */ FOR_EACH_BB_FN (block, cfun) { if (CONTAINING_RGN (block->index) != rgn) continue; FOR_EACH_EDGE (e, ei, block->succs) e->aux = NULL; } } } /* Free data computed for the finished region. */ void sched_rgn_local_free (void) { free (prob); sbitmap_vector_free (dom); sbitmap_vector_free (pot_split); sbitmap_vector_free (ancestor_edges); free (rgn_edges); } /* Free data computed for the finished region. */ void sched_rgn_local_finish (void) { if (current_nr_blocks > 1 && !sel_sched_p ()) { sched_rgn_local_free (); } } /* Setup scheduler infos. */ void rgn_setup_common_sched_info (void) { memcpy (&rgn_common_sched_info, &haifa_common_sched_info, sizeof (rgn_common_sched_info)); rgn_common_sched_info.fix_recovery_cfg = rgn_fix_recovery_cfg; rgn_common_sched_info.add_block = rgn_add_block; rgn_common_sched_info.estimate_number_of_insns = rgn_estimate_number_of_insns; rgn_common_sched_info.sched_pass_id = SCHED_RGN_PASS; common_sched_info = &rgn_common_sched_info; } /* Setup all *_sched_info structures (for the Haifa frontend and for the dependence analysis) in the interblock scheduler. */ void rgn_setup_sched_infos (void) { if (!sel_sched_p ()) memcpy (&rgn_sched_deps_info, &rgn_const_sched_deps_info, sizeof (rgn_sched_deps_info)); else memcpy (&rgn_sched_deps_info, &rgn_const_sel_sched_deps_info, sizeof (rgn_sched_deps_info)); sched_deps_info = &rgn_sched_deps_info; memcpy (&rgn_sched_info, &rgn_const_sched_info, sizeof (rgn_sched_info)); current_sched_info = &rgn_sched_info; } /* The one entry point in this file. */ void schedule_insns (void) { int rgn; /* Taking care of this degenerate case makes the rest of this code simpler. */ if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) return; rgn_setup_common_sched_info (); rgn_setup_sched_infos (); haifa_sched_init (); sched_rgn_init (reload_completed); bitmap_initialize (¬_in_df, &bitmap_default_obstack); /* Schedule every region in the subroutine. */ for (rgn = 0; rgn < nr_regions; rgn++) if (dbg_cnt (sched_region)) schedule_region (rgn); /* Clean up. */ sched_rgn_finish (); bitmap_release (¬_in_df); haifa_sched_finish (); } /* INSN has been added to/removed from current region. */ static void rgn_add_remove_insn (rtx_insn *insn, int remove_p) { if (!remove_p) rgn_n_insns++; else rgn_n_insns--; if (INSN_BB (insn) == target_bb) { if (!remove_p) target_n_insns++; else target_n_insns--; } } /* Extend internal data structures. */ void extend_regions (void) { rgn_table = XRESIZEVEC (region, rgn_table, n_basic_blocks_for_fn (cfun)); rgn_bb_table = XRESIZEVEC (int, rgn_bb_table, n_basic_blocks_for_fn (cfun)); block_to_bb = XRESIZEVEC (int, block_to_bb, last_basic_block_for_fn (cfun)); containing_rgn = XRESIZEVEC (int, containing_rgn, last_basic_block_for_fn (cfun)); } void rgn_make_new_region_out_of_new_block (basic_block bb) { int i; i = RGN_BLOCKS (nr_regions); /* I - first free position in rgn_bb_table. */ rgn_bb_table[i] = bb->index; RGN_NR_BLOCKS (nr_regions) = 1; RGN_HAS_REAL_EBB (nr_regions) = 0; RGN_DONT_CALC_DEPS (nr_regions) = 0; CONTAINING_RGN (bb->index) = nr_regions; BLOCK_TO_BB (bb->index) = 0; nr_regions++; RGN_BLOCKS (nr_regions) = i + 1; } /* BB was added to ebb after AFTER. */ static void rgn_add_block (basic_block bb, basic_block after) { extend_regions (); bitmap_set_bit (¬_in_df, bb->index); if (after == 0 || after == EXIT_BLOCK_PTR_FOR_FN (cfun)) { rgn_make_new_region_out_of_new_block (bb); RGN_DONT_CALC_DEPS (nr_regions - 1) = (after == EXIT_BLOCK_PTR_FOR_FN (cfun)); } else { int i, pos; /* We need to fix rgn_table, block_to_bb, containing_rgn and ebb_head. */ BLOCK_TO_BB (bb->index) = BLOCK_TO_BB (after->index); /* We extend ebb_head to one more position to easily find the last position of the last ebb in the current region. Thus, ebb_head[BLOCK_TO_BB (after) + 1] is _always_ valid for access. */ i = BLOCK_TO_BB (after->index) + 1; pos = ebb_head[i] - 1; /* Now POS is the index of the last block in the region. */ /* Find index of basic block AFTER. */ for (; rgn_bb_table[pos] != after->index; pos--) ; pos++; gcc_assert (pos > ebb_head[i - 1]); /* i - ebb right after "AFTER". */ /* ebb_head[i] - VALID. */ /* Source position: ebb_head[i] Destination position: ebb_head[i] + 1 Last position: RGN_BLOCKS (nr_regions) - 1 Number of elements to copy: (last_position) - (source_position) + 1 */ memmove (rgn_bb_table + pos + 1, rgn_bb_table + pos, ((RGN_BLOCKS (nr_regions) - 1) - (pos) + 1) * sizeof (*rgn_bb_table)); rgn_bb_table[pos] = bb->index; for (; i <= current_nr_blocks; i++) ebb_head [i]++; i = CONTAINING_RGN (after->index); CONTAINING_RGN (bb->index) = i; RGN_HAS_REAL_EBB (i) = 1; for (++i; i <= nr_regions; i++) RGN_BLOCKS (i)++; } } /* Fix internal data after interblock movement of jump instruction. For parameter meaning please refer to sched-int.h: struct sched_info: fix_recovery_cfg. */ static void rgn_fix_recovery_cfg (int bbi, int check_bbi, int check_bb_nexti) { int old_pos, new_pos, i; BLOCK_TO_BB (check_bb_nexti) = BLOCK_TO_BB (bbi); for (old_pos = ebb_head[BLOCK_TO_BB (check_bbi) + 1] - 1; rgn_bb_table[old_pos] != check_bb_nexti; old_pos--) ; gcc_assert (old_pos > ebb_head[BLOCK_TO_BB (check_bbi)]); for (new_pos = ebb_head[BLOCK_TO_BB (bbi) + 1] - 1; rgn_bb_table[new_pos] != bbi; new_pos--) ; new_pos++; gcc_assert (new_pos > ebb_head[BLOCK_TO_BB (bbi)]); gcc_assert (new_pos < old_pos); memmove (rgn_bb_table + new_pos + 1, rgn_bb_table + new_pos, (old_pos - new_pos) * sizeof (*rgn_bb_table)); rgn_bb_table[new_pos] = check_bb_nexti; for (i = BLOCK_TO_BB (bbi) + 1; i <= BLOCK_TO_BB (check_bbi); i++) ebb_head[i]++; } /* Return next block in ebb chain. For parameter meaning please refer to sched-int.h: struct sched_info: advance_target_bb. */ static basic_block advance_target_bb (basic_block bb, rtx_insn *insn) { if (insn) return 0; gcc_assert (BLOCK_TO_BB (bb->index) == target_bb && BLOCK_TO_BB (bb->next_bb->index) == target_bb); return bb->next_bb; } #endif /* Run instruction scheduler. */ static unsigned int rest_of_handle_live_range_shrinkage (void) { #ifdef INSN_SCHEDULING int saved; initialize_live_range_shrinkage (); saved = flag_schedule_interblock; flag_schedule_interblock = false; schedule_insns (); flag_schedule_interblock = saved; finish_live_range_shrinkage (); #endif return 0; } /* Run instruction scheduler. */ static unsigned int rest_of_handle_sched (void) { #ifdef INSN_SCHEDULING if (flag_selective_scheduling && ! maybe_skip_selective_scheduling ()) run_selective_scheduling (); else schedule_insns (); #endif return 0; } /* Run second scheduling pass after reload. */ static unsigned int rest_of_handle_sched2 (void) { #ifdef INSN_SCHEDULING if (flag_selective_scheduling2 && ! maybe_skip_selective_scheduling ()) run_selective_scheduling (); else { /* Do control and data sched analysis again, and write some more of the results to dump file. */ if (flag_sched2_use_superblocks) schedule_ebbs (); else schedule_insns (); } #endif return 0; } static unsigned int rest_of_handle_sched_fusion (void) { #ifdef INSN_SCHEDULING sched_fusion = true; schedule_insns (); sched_fusion = false; #endif return 0; } namespace { const pass_data pass_data_live_range_shrinkage = { RTL_PASS, /* type */ "lr_shrinkage", /* name */ OPTGROUP_NONE, /* optinfo_flags */ TV_LIVE_RANGE_SHRINKAGE, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_df_finish, /* todo_flags_finish */ }; class pass_live_range_shrinkage : public rtl_opt_pass { public: pass_live_range_shrinkage(gcc::context *ctxt) : rtl_opt_pass(pass_data_live_range_shrinkage, ctxt) {} /* opt_pass methods: */ bool gate (function *) final override { #ifdef INSN_SCHEDULING return flag_live_range_shrinkage; #else return 0; #endif } unsigned int execute (function *) final override { return rest_of_handle_live_range_shrinkage (); } }; // class pass_live_range_shrinkage } // anon namespace rtl_opt_pass * make_pass_live_range_shrinkage (gcc::context *ctxt) { return new pass_live_range_shrinkage (ctxt); } namespace { const pass_data pass_data_sched = { RTL_PASS, /* type */ "sched1", /* name */ OPTGROUP_NONE, /* optinfo_flags */ TV_SCHED, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_df_finish, /* todo_flags_finish */ }; class pass_sched : public rtl_opt_pass { public: pass_sched (gcc::context *ctxt) : rtl_opt_pass (pass_data_sched, ctxt) {} /* opt_pass methods: */ bool gate (function *) final override; unsigned int execute (function *) final override { return rest_of_handle_sched (); } }; // class pass_sched bool pass_sched::gate (function *) { #ifdef INSN_SCHEDULING return optimize > 0 && flag_schedule_insns && dbg_cnt (sched_func); #else return 0; #endif } } // anon namespace rtl_opt_pass * make_pass_sched (gcc::context *ctxt) { return new pass_sched (ctxt); } namespace { const pass_data pass_data_sched2 = { RTL_PASS, /* type */ "sched2", /* name */ OPTGROUP_NONE, /* optinfo_flags */ TV_SCHED2, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_df_finish, /* todo_flags_finish */ }; class pass_sched2 : public rtl_opt_pass { public: pass_sched2 (gcc::context *ctxt) : rtl_opt_pass (pass_data_sched2, ctxt) {} /* opt_pass methods: */ bool gate (function *) final override; unsigned int execute (function *) final override { return rest_of_handle_sched2 (); } }; // class pass_sched2 bool pass_sched2::gate (function *) { #ifdef INSN_SCHEDULING return optimize > 0 && flag_schedule_insns_after_reload && !targetm.delay_sched2 && dbg_cnt (sched2_func); #else return 0; #endif } } // anon namespace rtl_opt_pass * make_pass_sched2 (gcc::context *ctxt) { return new pass_sched2 (ctxt); } namespace { const pass_data pass_data_sched_fusion = { RTL_PASS, /* type */ "sched_fusion", /* name */ OPTGROUP_NONE, /* optinfo_flags */ TV_SCHED_FUSION, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_df_finish, /* todo_flags_finish */ }; class pass_sched_fusion : public rtl_opt_pass { public: pass_sched_fusion (gcc::context *ctxt) : rtl_opt_pass (pass_data_sched_fusion, ctxt) {} /* opt_pass methods: */ bool gate (function *) final override; unsigned int execute (function *) final override { return rest_of_handle_sched_fusion (); } }; // class pass_sched2 bool pass_sched_fusion::gate (function *) { #ifdef INSN_SCHEDULING /* Scheduling fusion relies on peephole2 to do real fusion work, so only enable it if peephole2 is in effect. */ return (optimize > 0 && flag_peephole2 && flag_schedule_fusion && targetm.sched.fusion_priority != NULL); #else return 0; #endif } } // anon namespace rtl_opt_pass * make_pass_sched_fusion (gcc::context *ctxt) { return new pass_sched_fusion (ctxt); } #if __GNUC__ >= 10 # pragma GCC diagnostic pop #endif