| /* Instruction scheduling pass. |
| Copyright (C) 1992-2021 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* 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 int 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 int check_live_1 (int, rtx); |
| static void update_live_1 (int, rtx); |
| static int is_pfree (rtx, int, int); |
| static int find_conditional_protection (rtx_insn *, int); |
| static int is_conditionally_protected (rtx, int, int); |
| static int is_prisky (rtx, int, int); |
| static int 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 1 if control flow graph should not be constructed, 0 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 int |
| 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 1; |
| |
| /* If we have any forced labels, then the cfg is not well structured. */ |
| if (forced_labels) |
| return 1; |
| |
| /* 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 1; |
| |
| /* 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 1; |
| |
| 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 1; |
| |
| set = single_set (insn); |
| if (set == NULL_RTX) |
| return 1; |
| |
| dest = SET_DEST (set); |
| if (!REG_P (dest) || !dead_or_set_p (next, dest)) |
| return 1; |
| } |
| |
| /* 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 1; |
| } |
| |
| /* All the tests passed. Consider the cfg well structured. */ |
| return 0; |
| } |
| |
| /* 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, unreachable; |
| int 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 = 0; |
| FOR_EACH_BB_FN (bb, cfun) |
| if (dfs_nr[bb->index] == 0) |
| { |
| unreachable = 1; |
| 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 = 0; |
| 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 = 1; |
| 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 = 1; |
| 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 = 1; |
| 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, rescan = 0, idx = *idxp, iter = 0, max_iter, *max_hdr; |
| int nblocks = n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; |
| |
| 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 = 1; |
| } |
| 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 = 0; |
| |
| 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 = 1; |
| } |
| 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 0 if x is a set of a register alive in the beginning of one |
| of the split-blocks of src, otherwise return 1. */ |
| |
| static int |
| check_live_1 (int src, rtx x) |
| { |
| int i; |
| int regno; |
| rtx reg = SET_DEST (x); |
| |
| if (reg == 0) |
| return 1; |
| |
| 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 1; |
| |
| return 0; |
| } |
| |
| if (!REG_P (reg)) |
| return 1; |
| |
| regno = REGNO (reg); |
| |
| if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) |
| { |
| /* Global registers are assumed live. */ |
| return 0; |
| } |
| 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 0; |
| } |
| } |
| } |
| 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 0; |
| } |
| } |
| } |
| |
| return 1; |
| } |
| |
| /* 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 1 if insn can be speculatively moved from block src to trg, |
| otherwise return 0. Called before first insertion of insn to |
| ready-list or before the scheduling. */ |
| |
| static int |
| 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 0; |
| |
| return 1; |
| } |
| |
| return 1; |
| } |
| |
| /* 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)); |
| } |
| } |
| |
| /* Nonzero 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 int |
| 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 1; |
| } |
| return 0; |
| } /* find_conditional_protection */ |
| |
| /* Returns 1 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 int |
| 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 1; |
| |
| /* Recursive step: search another insn1, "above" current insn1. */ |
| return is_conditionally_protected (insn1, bb_src, bb_trg); |
| } |
| |
| /* The chain does not exist. */ |
| return 0; |
| } /* is_conditionally_protected */ |
| |
| /* Returns 1 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 int |
| 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 0; |
| |
| 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 1; |
| |
| if (*(candp->split_bbs.first_member) == BLOCK_FOR_INSN (insn2)) |
| /* insn2 is a similar load, in a split-block. */ |
| return 1; |
| } |
| } |
| } |
| } |
| |
| /* Couldn't find a similar load. */ |
| return 0; |
| } /* is_pfree */ |
| |
| /* Return 1 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 int |
| is_prisky (rtx load_insn, int bb_src, int bb_trg) |
| { |
| if (FED_BY_SPEC_LOAD (load_insn)) |
| return 1; |
| |
| if (sd_lists_empty_p (load_insn, SD_LIST_BACK)) |
| /* Dependence may 'hide' out of the region. */ |
| return 1; |
| |
| if (is_conditionally_protected (load_insn, bb_src, bb_trg)) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* Insn is a candidate to be moved speculatively from bb_src to bb_trg. |
| Return 1 if insn is exception-free (and the motion is valid) |
| and 0 otherwise. */ |
| |
| static int |
| 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 1; |
| case TRAP_RISKY: |
| return 0; |
| default:; |
| } |
| |
| /* Handle loads. */ |
| if (!flag_schedule_speculative_load) |
| return 0; |
| IS_LOAD_INSN (insn) = 1; |
| switch (insn_class) |
| { |
| case IFREE: |
| return (1); |
| case IRISKY: |
| return 0; |
| case PFREE_CANDIDATE: |
| if (is_pfree (insn, bb_src, bb_trg)) |
| return 1; |
| /* 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 0; |
| 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 int can_schedule_ready_p (rtx_insn *); |
| static void begin_schedule_ready (rtx_insn *); |
| static ds_t new_ready (rtx_insn *, ds_t); |
| static int 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 nonzero if there are more insns that should be scheduled. */ |
| |
| static int |
| 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 nonzero if this |
| insn can be scheduled, nonzero if we should silently discard it. */ |
| |
| static int |
| 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 0; |
| |
| /* Should not move expensive instructions speculatively. */ |
| if (GET_CODE (PATTERN (insn)) != CLOBBER |
| && !targetm.sched.can_speculate_insn (insn)) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* 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 nonzero if we should include this dependence in priority |
| calculations. */ |
| |
| int |
| 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.c. */ |
| 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; |
| } |
| |
| /* 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); |
| 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; |
| if (dbg_cnt (sched_block)) |
| { |
| edge f; |
| 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); |
| 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], curr_state, |
| dfa_state_size); |
| if (sched_verbose >= 5) |
| fprintf (sched_dump, "saving state for edge %d->%d\n", |
| f->src->index, f->dest->index); |
| } |
| } |
| else |
| { |
| sched_rgn_n_insns += rgn_n_insns; |
| } |
| |
| /* 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 (); |
| |
| |