| /* Instruction scheduling pass. |
| Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
| 1999, 2000, 2001, 2002, 2003, 2004, 2005 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 2, 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 COPYING. If not, write to the Free |
| Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
| 02111-1307, USA. */ |
| |
| /* 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 "tm.h" |
| #include "toplev.h" |
| #include "rtl.h" |
| #include "tm_p.h" |
| #include "hard-reg-set.h" |
| #include "regs.h" |
| #include "function.h" |
| #include "flags.h" |
| #include "insn-config.h" |
| #include "insn-attr.h" |
| #include "except.h" |
| #include "toplev.h" |
| #include "recog.h" |
| #include "cfglayout.h" |
| #include "params.h" |
| #include "sched-int.h" |
| #include "target.h" |
| |
| /* Define when we want to do count REG_DEAD notes before and after scheduling |
| for sanity checking. We can't do that when conditional execution is used, |
| as REG_DEAD exist only for unconditional deaths. */ |
| |
| #if !defined (HAVE_conditional_execution) && defined (ENABLE_CHECKING) |
| #define CHECK_DEAD_NOTES 1 |
| #else |
| #define CHECK_DEAD_NOTES 0 |
| #endif |
| |
| |
| #ifdef INSN_SCHEDULING |
| /* Some accessor macros for h_i_d members only used within this file. */ |
| #define INSN_REF_COUNT(INSN) (h_i_d[INSN_UID (INSN)].ref_count) |
| #define FED_BY_SPEC_LOAD(insn) (h_i_d[INSN_UID (insn)].fed_by_spec_load) |
| #define IS_LOAD_INSN(insn) (h_i_d[INSN_UID (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); |
| static bool sched_is_disabled_for_current_region_p (void); |
| |
| /* A region is the main entity for interblock scheduling: insns |
| are allowed to move between blocks in the same region, along |
| control flow graph edges, in the 'up' direction. */ |
| typedef struct |
| { |
| int rgn_nr_blocks; /* Number of blocks in region. */ |
| int rgn_blocks; /* cblocks in the region (actually index in rgn_bb_table). */ |
| } |
| region; |
| |
| /* Number of regions in the procedure. */ |
| static int nr_regions; |
| |
| /* Table of region descriptions. */ |
| static region *rgn_table; |
| |
| /* Array of lists of regions' blocks. */ |
| static int *rgn_bb_table; |
| |
| /* 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. */ |
| static int *block_to_bb; |
| |
| /* The number of the region containing a block. */ |
| static int *containing_rgn; |
| |
| #define RGN_NR_BLOCKS(rgn) (rgn_table[rgn].rgn_nr_blocks) |
| #define RGN_BLOCKS(rgn) (rgn_table[rgn].rgn_blocks) |
| #define BLOCK_TO_BB(block) (block_to_bb[block]) |
| #define CONTAINING_RGN(block) (containing_rgn[block]) |
| |
| void debug_regions (void); |
| static void find_single_block_region (void); |
| static void find_rgns (void); |
| static bool too_large (int, int *, int *); |
| |
| extern void debug_live (int, int); |
| |
| /* Blocks of the current region being scheduled. */ |
| static int current_nr_blocks; |
| static int current_blocks; |
| |
| /* The mapping from bb to block. */ |
| #define BB_TO_BLOCK(bb) (rgn_bb_table[current_blocks + (bb)]) |
| |
| /* 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. */ |
| typedef struct |
| { |
| basic_block *first_member; |
| int nr_members; |
| } |
| bblst; |
| |
| typedef struct |
| { |
| char is_valid; |
| char is_speculative; |
| int src_prob; |
| bblst split_bbs; |
| bblst update_bbs; |
| } |
| candidate; |
| |
| static candidate *candidate_table; |
| |
| /* 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; |
| |
| #define IS_VALID(src) ( candidate_table[src].is_valid ) |
| #define IS_SPECULATIVE(src) ( candidate_table[src].is_speculative ) |
| #define SRC_PROB(src) ( candidate_table[src].src_prob ) |
| |
| /* The bb being currently scheduled. */ |
| static int target_bb; |
| |
| /* List of edges. */ |
| typedef struct |
| { |
| edge *first_member; |
| int nr_members; |
| } |
| edgelst; |
| |
| 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) \ |
| ( TEST_BIT (dom[bb_src], bb_trg) ) |
| |
| /* Probability: Prob[i] is a float in [0, 1] which is the probability |
| of bb i relative to the region entry. */ |
| static float *prob; |
| |
| /* The probability of bb_src, relative to bb_trg. Note, that while the |
| 'prob[bb]' is a float in [0, 1], this macro returns an integer |
| in [0, 100]. */ |
| #define GET_SRC_PROB(bb_src, bb_trg) ((int) (100.0 * (prob[bb_src] / \ |
| prob[bb_trg]))) |
| |
| /* 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; |
| |
| static void compute_dom_prob_ps (int); |
| |
| #define INSN_PROBABILITY(INSN) (SRC_PROB (BLOCK_TO_BB (BLOCK_NUM (INSN)))) |
| #define IS_SPECULATIVE_INSN(INSN) (IS_SPECULATIVE (BLOCK_TO_BB (BLOCK_NUM (INSN)))) |
| #define INSN_BB(INSN) (BLOCK_TO_BB (BLOCK_NUM (INSN))) |
| |
| /* Parameters affecting the decision of rank_for_schedule(). |
| ??? Nope. But MIN_PROBABILITY is used in compute_trg_info. */ |
| #define MIN_PROBABILITY 40 |
| |
| /* Speculative scheduling functions. */ |
| static int check_live_1 (int, rtx); |
| static void update_live_1 (int, rtx); |
| static int check_live (rtx, int); |
| static void update_live (rtx, int); |
| static void set_spec_fed (rtx); |
| static int is_pfree (rtx, int, int); |
| static int find_conditional_protection (rtx, int); |
| static int is_conditionally_protected (rtx, int, int); |
| static int is_prisky (rtx, int, int); |
| static int is_exception_free (rtx, int, int); |
| |
| static bool sets_likely_spilled (rtx); |
| static void sets_likely_spilled_1 (rtx, rtx, void *); |
| static void add_branch_dependences (rtx, rtx); |
| static void compute_block_backward_dependences (int); |
| void debug_dependencies (void); |
| |
| static void init_regions (void); |
| static void schedule_region (int); |
| static rtx concat_INSN_LIST (rtx, rtx); |
| static void concat_insn_mem_list (rtx, rtx, rtx *, rtx *); |
| static void propagate_deps (int, struct deps *); |
| 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; |
| |
| /* 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 flow.c |
| computes an accurate cfg for EH. */ |
| if (current_function_has_exception_handlers ()) |
| return 1; |
| |
| /* If we have non-jumping insns which refer to labels, then we consider |
| the cfg not well structured. */ |
| FOR_EACH_BB (b) |
| FOR_BB_INSNS (b, insn) |
| { |
| /* Check for labels referred by non-jump insns. */ |
| if (NONJUMP_INSN_P (insn) || CALL_P (insn)) |
| { |
| rtx note = find_reg_note (insn, REG_LABEL, NULL_RTX); |
| if (note |
| && ! (JUMP_P (NEXT_INSN (insn)) |
| && find_reg_note (NEXT_INSN (insn), REG_LABEL, |
| XEXP (note, 0)))) |
| return 1; |
| } |
| /* If this function has a computed jump, then we consider the cfg |
| not well structured. */ |
| else if (JUMP_P (insn) && computed_jump_p (insn)) |
| 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 (b) |
| { |
| if (EDGE_COUNT (b->preds) == 0 |
| || (EDGE_PRED (b, 0)->src == b |
| && EDGE_COUNT (b->preds) == 1)) |
| 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) |
| { |
| int i; |
| |
| /* 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_SBITMAP (set, 0, i, |
| { |
| 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. */ |
| |
| 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: "); |
| |
| for (bb = 0; bb < rgn_table[rgn].rgn_nr_blocks; bb++) |
| { |
| current_blocks = RGN_BLOCKS (rgn); |
| |
| gcc_assert (bb == BLOCK_TO_BB (BB_TO_BLOCK (bb))); |
| fprintf (sched_dump, " %d/%d ", bb, BB_TO_BLOCK (bb)); |
| } |
| |
| fprintf (sched_dump, "\n\n"); |
| } |
| } |
| |
| /* 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 (void) |
| { |
| basic_block bb; |
| |
| nr_regions = 0; |
| |
| FOR_EACH_BB (bb) |
| { |
| rgn_bb_table[nr_regions] = bb->index; |
| RGN_NR_BLOCKS (nr_regions) = 1; |
| RGN_BLOCKS (nr_regions) = nr_regions; |
| CONTAINING_RGN (bb->index) = nr_regions; |
| BLOCK_TO_BB (bb->index) = 0; |
| nr_regions++; |
| } |
| } |
| |
| /* 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) += (INSN_LUID (BB_END (BASIC_BLOCK (block))) |
| - INSN_LUID (BB_HEAD (BASIC_BLOCK (block)))); |
| |
| return ((*num_bbs > PARAM_VALUE (PARAM_MAX_SCHED_REGION_BLOCKS)) |
| || (*num_insns > PARAM_VALUE (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]) \ |
| RESET_BIT (inner, hdr); \ |
| else if (dfs_nr[max_hdr[blk]] < dfs_nr[hdr]) \ |
| { \ |
| RESET_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 |
| 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; |
| |
| /* Note if a block is a natural loop header. */ |
| sbitmap header; |
| |
| /* Note if a block is a natural inner loop header. */ |
| sbitmap inner; |
| |
| /* Note if a block is in the block queue. */ |
| sbitmap in_queue; |
| |
| /* Note if a block is in the block queue. */ |
| sbitmap in_stack; |
| |
| /* 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 = xmalloc (last_basic_block * sizeof (int)); |
| dfs_nr = xcalloc (last_basic_block, sizeof (int)); |
| stack = xmalloc (n_edges * sizeof (edge_iterator)); |
| |
| inner = sbitmap_alloc (last_basic_block); |
| sbitmap_ones (inner); |
| |
| header = sbitmap_alloc (last_basic_block); |
| sbitmap_zero (header); |
| |
| in_queue = sbitmap_alloc (last_basic_block); |
| sbitmap_zero (in_queue); |
| |
| in_stack = sbitmap_alloc (last_basic_block); |
| sbitmap_zero (in_stack); |
| |
| for (i = 0; i < last_basic_block; 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 (EDGE_SUCC (ENTRY_BLOCK_PTR, 0)->dest->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); |
| RESET_BIT (in_stack, child); |
| if (max_hdr[child] >= 0 && TEST_BIT (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); |
| 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 (TEST_BIT (in_stack, child)) |
| { |
| no_loops = 0; |
| 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 && TEST_BIT (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 (bb) |
| { |
| 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 (bb) |
| 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 (bb) |
| degree[bb->index] = EDGE_COUNT (bb->preds); |
| |
| /* Do not perform region scheduling if there are any unreachable |
| blocks. */ |
| if (!unreachable) |
| { |
| int *queue; |
| |
| if (no_loops) |
| SET_BIT (header, 0); |
| |
| /* Second traversal:find reducible inner loops and topologically sort |
| block of each region. */ |
| |
| queue = xmalloc (n_basic_blocks * sizeof (int)); |
| |
| /* Find blocks which are inner loop headers. We still have non-reducible |
| loops to consider at this point. */ |
| FOR_EACH_BB (bb) |
| { |
| if (TEST_BIT (header, bb->index) && TEST_BIT (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 (jbb) |
| { |
| /* 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) |
| 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]; |
| |
| /* Decrease degree of all I's successors for topological |
| ordering. */ |
| FOR_EACH_EDGE (e, ei, bb->succs) |
| if (e->dest != EXIT_BLOCK_PTR) |
| --degree[e->dest->index]; |
| |
| /* Estimate # insns, and count # blocks in the region. */ |
| num_bbs = 1; |
| num_insns = (INSN_LUID (BB_END (bb)) |
| - INSN_LUID (BB_HEAD (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 (jbb) |
| /* Leaf nodes have only a single successor which must |
| be EXIT_BLOCK. */ |
| if (EDGE_COUNT (jbb->succs) == 1 |
| && EDGE_SUCC (jbb, 0)->dest == EXIT_BLOCK_PTR) |
| { |
| queue[++tail] = jbb->index; |
| 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) |
| continue; |
| |
| node = e->src->index; |
| |
| if (max_hdr[node] == loop_head && node != bb->index) |
| { |
| /* This is a loop latch. */ |
| queue[++tail] = node; |
| 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 can not 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 (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 |
| || max_hdr[node] != loop_head) |
| { |
| tail = -1; |
| break; |
| } |
| else if (!TEST_BIT (in_queue, node) && node != bb->index) |
| { |
| queue[++tail] = node; |
| 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++; |
| 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 (child)->succs) |
| if (e->dest != EXIT_BLOCK_PTR) |
| --degree[e->dest->index]; |
| } |
| else |
| --head; |
| } |
| ++nr_regions; |
| } |
| } |
| } |
| free (queue); |
| } |
| |
| /* Any block that did not end up in a region is placed into a region |
| by itself. */ |
| FOR_EACH_BB (bb) |
| if (degree[bb->index] >= 0) |
| { |
| rgn_bb_table[idx] = bb->index; |
| RGN_NR_BLOCKS (nr_regions) = 1; |
| RGN_BLOCKS (nr_regions) = idx++; |
| CONTAINING_RGN (bb->index) = nr_regions++; |
| BLOCK_TO_BB (bb->index) = 0; |
| } |
| |
| free (max_hdr); |
| free (dfs_nr); |
| free (stack); |
| sbitmap_free (header); |
| sbitmap_free (inner); |
| sbitmap_free (in_queue); |
| sbitmap_free (in_stack); |
| } |
| |
| /* 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) |
| { |
| int pred_bb; |
| int nr_out_edges, nr_rgn_out_edges; |
| edge_iterator in_ei, out_ei; |
| edge in_edge, out_edge; |
| |
| prob[bb] = 0.0; |
| if (IS_RGN_ENTRY (bb)) |
| { |
| SET_BIT (dom[bb], 0); |
| prob[bb] = 1.0; |
| return; |
| } |
| |
| /* Initialize dom[bb] to '111..1'. */ |
| sbitmap_ones (dom[bb]); |
| |
| FOR_EACH_EDGE (in_edge, in_ei, BASIC_BLOCK (BB_TO_BLOCK (bb))->preds) |
| { |
| if (in_edge->src == ENTRY_BLOCK_PTR) |
| continue; |
| |
| pred_bb = BLOCK_TO_BB (in_edge->src->index); |
| sbitmap_a_and_b (dom[bb], dom[bb], dom[pred_bb]); |
| sbitmap_a_or_b (ancestor_edges[bb], |
| ancestor_edges[bb], ancestor_edges[pred_bb]); |
| |
| SET_BIT (ancestor_edges[bb], EDGE_TO_BIT (in_edge)); |
| |
| sbitmap_a_or_b (pot_split[bb], pot_split[bb], pot_split[pred_bb]); |
| |
| nr_out_edges = 0; |
| nr_rgn_out_edges = 0; |
| |
| FOR_EACH_EDGE (out_edge, out_ei, in_edge->src->succs) |
| { |
| ++nr_out_edges; |
| |
| /* The successor doesn't belong in the region? */ |
| if (out_edge->dest != EXIT_BLOCK_PTR |
| && CONTAINING_RGN (out_edge->dest->index) |
| != CONTAINING_RGN (BB_TO_BLOCK (bb))) |
| ++nr_rgn_out_edges; |
| |
| SET_BIT (pot_split[bb], EDGE_TO_BIT (out_edge)); |
| } |
| |
| /* Now nr_rgn_out_edges is the number of region-exit edges from |
| pred, and nr_out_edges will be the number of pred out edges |
| not leaving the region. */ |
| nr_out_edges -= nr_rgn_out_edges; |
| if (nr_rgn_out_edges > 0) |
| prob[bb] += 0.9 * prob[pred_bb] / nr_out_edges; |
| else |
| prob[bb] += prob[pred_bb] / nr_out_edges; |
| } |
| |
| SET_BIT (dom[bb], bb); |
| sbitmap_difference (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), |
| (int) (100.0 * prob[bb])); |
| } |
| |
| /* 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) |
| { |
| sbitmap src = sbitmap_alloc (pot_split[bb_src]->n_bits); |
| sbitmap_copy (src, pot_split[bb_src]); |
| |
| sbitmap_difference (src, src, pot_split[bb_trg]); |
| extract_edgelst (src, bl); |
| sbitmap_free (src); |
| } |
| |
| /* 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; |
| int i, j, k, update_idx; |
| basic_block block; |
| sbitmap visited; |
| edge_iterator ei; |
| edge e; |
| |
| /* APPLE LOCAL begin lno */ |
| el.nr_members = 0; |
| el.first_member = 0; |
| /* APPLE LOCAL end lno */ |
| |
| /* 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 = 100; |
| |
| visited = sbitmap_alloc (last_basic_block - (INVALID_BLOCK + 1)); |
| |
| for (i = trg + 1; i < current_nr_blocks; i++) |
| { |
| sp = candidate_table + i; |
| |
| sp->is_valid = IS_DOMINATED (i, trg); |
| if (sp->is_valid) |
| { |
| sp->src_prob = GET_SRC_PROB (i, trg); |
| sp->is_valid = (sp->src_prob >= MIN_PROBABILITY); |
| } |
| |
| 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; |
| sbitmap_zero (visited); |
| for (j = 0; j < el.nr_members; j++) |
| { |
| block = el.first_member[j]->src; |
| FOR_EACH_EDGE (e, ei, block->succs) |
| { |
| if (!TEST_BIT (visited, |
| e->dest->index - (INVALID_BLOCK + 1))) |
| { |
| 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; |
| SET_BIT (visited, |
| e->dest->index - (INVALID_BLOCK + 1)); |
| 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; |
| } |
| } |
| |
| sbitmap_free (visited); |
| } |
| |
| /* Print candidates info, for debugging purposes. Callable from debugger. */ |
| |
| 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. */ |
| |
| 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. */ |
| |
| /* 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 = hard_regno_nregs[regno][GET_MODE (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]; |
| |
| if (REGNO_REG_SET_P (b->global_live_at_start, 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]; |
| |
| if (REGNO_REG_SET_P (b->global_live_at_start, 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 (regno >= FIRST_PSEUDO_REGISTER || !global_regs[regno]) |
| { |
| if (regno < FIRST_PSEUDO_REGISTER) |
| { |
| int j = hard_regno_nregs[regno][GET_MODE (reg)]; |
| while (--j >= 0) |
| { |
| for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++) |
| { |
| basic_block b = candidate_table[src].update_bbs.first_member[i]; |
| |
| SET_REGNO_REG_SET (b->global_live_at_start, regno + j); |
| } |
| } |
| } |
| else |
| { |
| for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++) |
| { |
| basic_block b = candidate_table[src].update_bbs.first_member[i]; |
| |
| SET_REGNO_REG_SET (b->global_live_at_start, regno); |
| } |
| } |
| } |
| } |
| |
| /* 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, 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, 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) \ |
| || (TEST_BIT (ancestor_edges[bb_to], \ |
| EDGE_TO_BIT (EDGE_PRED (BASIC_BLOCK (BB_TO_BLOCK (bb_from)), 0))))) |
| |
| /* Turns on the fed_by_spec_load flag for insns fed by load_insn. */ |
| |
| static void |
| set_spec_fed (rtx load_insn) |
| { |
| rtx link; |
| |
| for (link = INSN_DEPEND (load_insn); link; link = XEXP (link, 1)) |
| if (GET_MODE (link) == VOIDmode) |
| FED_BY_SPEC_LOAD (XEXP (link, 0)) = 1; |
| } /* set_spec_fed */ |
| |
| /* 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, int load_insn_bb) |
| { |
| rtx link; |
| |
| /* Iterate through DEF-USE forward dependences. */ |
| for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1)) |
| { |
| rtx next = XEXP (link, 0); |
| 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) |
| && GET_MODE (link) == VOIDmode |
| && (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 a the two DEF-USE |
| chains: |
| insn1 -> ... -> conditional-branch |
| insn1 -> ... -> load_insn, |
| and if a flow path exist: |
| insn1 -> ... -> conditional-branch -> ... -> load_insn, |
| and if insn1 is on the path |
| region-entry -> ... -> bb_trg -> ... load_insn. |
| |
| Locate insn1 by climbing on LOG_LINKS from load_insn. |
| Locate the branch by following INSN_DEPEND from insn1. */ |
| |
| static int |
| is_conditionally_protected (rtx load_insn, int bb_src, int bb_trg) |
| { |
| rtx link; |
| |
| for (link = LOG_LINKS (load_insn); link; link = XEXP (link, 1)) |
| { |
| rtx insn1 = XEXP (link, 0); |
| |
| /* Must be a DEF-USE dependence upon non-branch. */ |
| if (GET_MODE (link) != VOIDmode |
| || 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) |
| { |
| rtx back_link; |
| candidate *candp = candidate_table + bb_src; |
| |
| if (candp->split_bbs.nr_members != 1) |
| /* Must have exactly one escape block. */ |
| return 0; |
| |
| for (back_link = LOG_LINKS (load_insn); |
| back_link; back_link = XEXP (back_link, 1)) |
| { |
| rtx insn1 = XEXP (back_link, 0); |
| |
| if (GET_MODE (back_link) == VOIDmode) |
| { |
| /* Found a DEF-USE dependence (insn1, load_insn). */ |
| rtx fore_link; |
| |
| for (fore_link = INSN_DEPEND (insn1); |
| fore_link; fore_link = XEXP (fore_link, 1)) |
| { |
| rtx insn2 = XEXP (fore_link, 0); |
| if (GET_MODE (fore_link) == VOIDmode) |
| { |
| /* 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 (LOG_LINKS (load_insn) == NULL) |
| /* 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, 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. */ |
| 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; |
| /* Nonzero if the last scheduled insn was a jump. */ |
| static int last_was_jump; |
| |
| /* Implementations of the sched_info functions for region scheduling. */ |
| static void init_ready_list (struct ready_list *); |
| static int can_schedule_ready_p (rtx); |
| static int new_ready (rtx); |
| static int schedule_more_p (void); |
| static const char *rgn_print_insn (rtx, int); |
| static int rgn_rank (rtx, rtx); |
| static int contributes_to_priority (rtx, rtx); |
| static void compute_jump_reg_dependencies (rtx, regset, regset, regset); |
| |
| /* Return nonzero if there are more insns that should be scheduled. */ |
| |
| static int |
| schedule_more_p (void) |
| { |
| return ! last_was_jump && 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 (struct ready_list *ready) |
| { |
| rtx prev_head = current_sched_info->prev_head; |
| rtx next_tail = current_sched_info->next_tail; |
| int bb_src; |
| rtx insn; |
| |
| target_n_insns = 0; |
| sched_target_n_insns = 0; |
| sched_n_insns = 0; |
| last_was_jump = 0; |
| |
| /* Print debugging information. */ |
| if (sched_verbose >= 5) |
| debug_dependencies (); |
| |
| /* Prepare current target block info. */ |
| if (current_nr_blocks > 1) |
| { |
| candidate_table = xmalloc (current_nr_blocks * sizeof (candidate)); |
| |
| 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 = xmalloc (bblst_size * sizeof (basic_block)); |
| |
| edgelst_last = 0; |
| edgelst_table = xmalloc (rgn_nr_edges * sizeof (edge)); |
| |
| 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)) |
| { |
| if (INSN_DEP_COUNT (insn) == 0) |
| { |
| ready_add (ready, insn); |
| |
| if (targetm.sched.adjust_priority) |
| INSN_PRIORITY (insn) = |
| targetm.sched.adjust_priority (insn, INSN_PRIORITY (insn)); |
| } |
| target_n_insns++; |
| } |
| |
| /* 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 src_head; |
| rtx src_next_tail; |
| rtx tail, head; |
| |
| get_block_head_tail (BB_TO_BLOCK (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)) |
| continue; |
| |
| if (!CANT_MOVE (insn) |
| && (!IS_SPECULATIVE_INSN (insn) |
| || ((recog_memoized (insn) < 0 |
| || min_insn_conflict_delay (curr_state, |
| insn, insn) <= 3) |
| && check_live (insn, bb_src) |
| && is_exception_free (insn, bb_src, target_bb)))) |
| if (INSN_DEP_COUNT (insn) == 0) |
| { |
| ready_add (ready, insn); |
| |
| if (targetm.sched.adjust_priority) |
| INSN_PRIORITY (insn) = |
| targetm.sched.adjust_priority (insn, INSN_PRIORITY (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) |
| { |
| if (JUMP_P (insn)) |
| last_was_jump = 1; |
| |
| /* An interblock motion? */ |
| if (INSN_BB (insn) != target_bb) |
| { |
| basic_block b1; |
| |
| if (IS_SPECULATIVE_INSN (insn)) |
| { |
| if (!check_live (insn, INSN_BB (insn))) |
| return 0; |
| 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++; |
| |
| /* Update source block boundaries. */ |
| b1 = BLOCK_FOR_INSN (insn); |
| if (insn == BB_HEAD (b1) && insn == BB_END (b1)) |
| { |
| /* We moved all the insns in the basic block. |
| Emit a note after the last insn and update the |
| begin/end boundaries to point to the note. */ |
| rtx note = emit_note_after (NOTE_INSN_DELETED, insn); |
| BB_HEAD (b1) = note; |
| BB_END (b1) = note; |
| } |
| else if (insn == BB_END (b1)) |
| { |
| /* We took insns from the end of the basic block, |
| so update the end of block boundary so that it |
| points to the first insn we did not move. */ |
| BB_END (b1) = PREV_INSN (insn); |
| } |
| else if (insn == BB_HEAD (b1)) |
| { |
| /* We took insns from the start of the basic block, |
| so update the start of block boundary so that |
| it points to the first insn we did not move. */ |
| BB_HEAD (b1) = NEXT_INSN (insn); |
| } |
| } |
| else |
| { |
| /* In block motion. */ |
| sched_target_n_insns++; |
| } |
| sched_n_insns++; |
| |
| return 1; |
| } |
| |
| /* Called after INSN has all its dependencies resolved. Return nonzero |
| if it should be moved to the ready list or the queue, or zero if we |
| should silently discard it. */ |
| static int |
| new_ready (rtx next) |
| { |
| /* For speculative insns, before inserting to ready/queue, |
| check live, exception-free, and issue-delay. */ |
| if (INSN_BB (next) != target_bb |
| && (!IS_VALID (INSN_BB (next)) |
| || CANT_MOVE (next) |
| || (IS_SPECULATIVE_INSN (next) |
| && ((recog_memoized (next) >= 0 |
| && min_insn_conflict_delay (curr_state, next, next) > 3) |
| || !check_live (next, INSN_BB (next)) |
| || !is_exception_free (next, INSN_BB (next), target_bb))))) |
| return 0; |
| return 1; |
| } |
| |
| /* 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 (rtx 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 insn1, rtx 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. */ |
| |
| static int |
| contributes_to_priority (rtx next, rtx insn) |
| { |
| return BLOCK_NUM (next) == BLOCK_NUM (insn); |
| } |
| |
| /* INSN is a JUMP_INSN, COND_SET is the set of registers that are |
| conditionally set before INSN. Store the set of registers that |
| must be considered as used by this jump in USED and that of |
| registers that must be considered as set in SET. */ |
| |
| static void |
| compute_jump_reg_dependencies (rtx insn ATTRIBUTE_UNUSED, |
| regset cond_exec ATTRIBUTE_UNUSED, |
| regset used ATTRIBUTE_UNUSED, |
| regset set ATTRIBUTE_UNUSED) |
| { |
| /* Nothing to do here, since we postprocess jumps in |
| add_branch_dependences. */ |
| } |
| |
| /* Used in schedule_insns to initialize current_sched_info for scheduling |
| regions (or single basic blocks). */ |
| |
| static struct sched_info region_sched_info = |
| { |
| init_ready_list, |
| can_schedule_ready_p, |
| schedule_more_p, |
| new_ready, |
| rgn_rank, |
| rgn_print_insn, |
| contributes_to_priority, |
| compute_jump_reg_dependencies, |
| |
| NULL, NULL, |
| NULL, NULL, |
| 0, 0, 0 |
| }; |
| |
| /* Determine if PAT sets a CLASS_LIKELY_SPILLED_P register. */ |
| |
| static bool |
| sets_likely_spilled (rtx pat) |
| { |
| bool ret = false; |
| note_stores (pat, sets_likely_spilled_1, &ret); |
| return ret; |
| } |
| |
| static void |
| sets_likely_spilled_1 (rtx x, rtx pat, void *data) |
| { |
| bool *ret = (bool *) data; |
| |
| if (GET_CODE (pat) == SET |
| && REG_P (x) |
| && REGNO (x) < FIRST_PSEUDO_REGISTER |
| && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x)))) |
| *ret = true; |
| } |
| |
| /* Add dependences so that branches are scheduled to run last in their |
| block. */ |
| |
| static void |
| add_branch_dependences (rtx head, rtx tail) |
| { |
| rtx insn, last; |
| |
| /* For all branches, calls, uses, clobbers, cc0 setters, 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. |
| |
| cc0 setters remain at the end because they can't be moved away from |
| their cc0 user. |
| |
| Insns setting CLASS_LIKELY_SPILLED_P registers (usually return values) |
| are not moved before reload because we can wind up with register |
| allocation failures. */ |
| |
| insn = tail; |
| last = 0; |
| while (CALL_P (insn) |
| || JUMP_P (insn) |
| || (NONJUMP_INSN_P (insn) |
| && (GET_CODE (PATTERN (insn)) == USE |
| || GET_CODE (PATTERN (insn)) == CLOBBER |
| || can_throw_internal (insn) |
| #ifdef HAVE_cc0 |
| || sets_cc0_p (PATTERN (insn)) |
| #endif |
| || (!reload_completed |
| && sets_likely_spilled (PATTERN (insn))))) |
| || NOTE_P (insn)) |
| { |
| if (!NOTE_P (insn)) |
| { |
| if (last != 0 && !find_insn_list (insn, LOG_LINKS (last))) |
| { |
| add_dependence (last, insn, REG_DEP_ANTI); |
| INSN_REF_COUNT (insn)++; |
| } |
| |
| CANT_MOVE (insn) = 1; |
| |
| last = insn; |
| } |
| |
| /* Don't overrun the bounds of the basic block. */ |
| if (insn == head) |
| break; |
| |
| insn = PREV_INSN (insn); |
| } |
| |
| /* Make sure these insns are scheduled last in their block. */ |
| insn = last; |
| if (insn != 0) |
| while (insn != head) |
| { |
| insn = prev_nonnote_insn (insn); |
| |
| if (INSN_REF_COUNT (insn) != 0) |
| continue; |
| |
| add_dependence (last, insn, REG_DEP_ANTI); |
| INSN_REF_COUNT (insn) = 1; |
| } |
| } |
| |
| /* 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 struct deps *bb_deps; |
| |
| /* Duplicate the INSN_LIST elements of COPY and prepend them to OLD. */ |
| |
| static rtx |
| concat_INSN_LIST (rtx copy, rtx old) |
| { |
| rtx new = old; |
| for (; copy ; copy = XEXP (copy, 1)) |
| new = alloc_INSN_LIST (XEXP (copy, 0), new); |
| return new; |
| } |
| |
| static void |
| concat_insn_mem_list (rtx copy_insns, rtx copy_mems, rtx *old_insns_p, |
| rtx *old_mems_p) |
| { |
| rtx new_insns = *old_insns_p; |
| rtx new_mems = *old_mems_p; |
| |
| while (copy_insns) |
| { |
| new_insns = alloc_INSN_LIST (XEXP (copy_insns, 0), new_insns); |
| new_mems = alloc_EXPR_LIST (VOIDmode, XEXP (copy_mems, 0), new_mems); |
| copy_insns = XEXP (copy_insns, 1); |
| copy_mems = XEXP (copy_mems, 1); |
| } |
| |
| *old_insns_p = new_insns; |
| *old_mems_p = new_mems; |
| } |
| |
| /* 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, struct deps *pred_deps) |
| { |
| basic_block block = BASIC_BLOCK (BB_TO_BLOCK (bb)); |
| edge_iterator ei; |
| edge e; |
| |
| /* bb's structures are inherited by its successors. */ |
| FOR_EACH_EDGE (e, ei, block->succs) |
| { |
| struct deps *succ_deps; |
| unsigned reg; |
| reg_set_iterator rsi; |
| |
| /* Only bbs "below" bb, in the same region, are interesting. */ |
| if (e->dest == EXIT_BLOCK_PTR |
| || CONTAINING_RGN (block->index) != CONTAINING_RGN (e->dest->index) |
| || BLOCK_TO_BB (e->dest->index) <= bb) |
| continue; |
| |
| succ_deps = bb_deps + BLOCK_TO_BB (e->dest->index); |
| |
| /* 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->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->last_pending_memory_flush |
| = concat_INSN_LIST (pred_deps->last_pending_memory_flush, |
| succ_deps->last_pending_memory_flush); |
| |
| succ_deps->pending_lists_length += pred_deps->pending_lists_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); |
| |
| /* 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); |
| } |
| |
| /* 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; |
| |
| /* 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; |
| } |
| |
| /* Compute backward 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. Two lists are |
| maintained by sched_analyze (): reg_last[].sets for 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]) |
| ; - 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_backward_dependences (int bb) |
| { |
| rtx head, tail; |
| struct deps tmp_deps; |
| |
| tmp_deps = bb_deps[bb]; |
| |
| /* Do the analysis for this block. */ |
| get_block_head_tail (BB_TO_BLOCK (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); |
| } |
| |
| /* 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); |
| } |
| } |
| |
| /* Print dependences for debugging, callable from debugger. */ |
| |
| void |
| debug_dependencies (void) |
| { |
| int bb; |
| |
| fprintf (sched_dump, ";; --------------- forward dependences: ------------ \n"); |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| { |
| rtx head, tail; |
| rtx next_tail; |
| rtx insn; |
| |
| get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); |
| next_tail = NEXT_INSN (tail); |
| fprintf (sched_dump, "\n;; --- Region Dependences --- b %d bb %d \n", |
| BB_TO_BLOCK (bb), bb); |
| |
| 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)) |
| { |
| rtx link; |
| |
| if (! INSN_P (insn)) |
| { |
| int n; |
| fprintf (sched_dump, ";; %6d ", INSN_UID (insn)); |
| if (NOTE_P (insn)) |
| { |
| n = NOTE_LINE_NUMBER (insn); |
| if (n < 0) |
| fprintf (sched_dump, "%s\n", GET_NOTE_INSN_NAME (n)); |
| else |
| { |
| expanded_location xloc; |
| NOTE_EXPANDED_LOCATION (xloc, insn); |
| fprintf (sched_dump, "line %d, file %s\n", |
| xloc.line, xloc.file); |
| } |
| } |
| 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), |
| INSN_BB (insn), |
| INSN_DEP_COUNT (insn), |
| INSN_PRIORITY (insn), |
| insn_cost (insn, 0, 0)); |
| |
| if (recog_memoized (insn) < 0) |
| fprintf (sched_dump, "nothing"); |
| else |
| print_reservation (sched_dump, insn); |
| |
| fprintf (sched_dump, "\t: "); |
| for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1)) |
| fprintf (sched_dump, "%d ", INSN_UID (XEXP (link, 0))); |
| fprintf (sched_dump, "\n"); |
| } |
| } |
| fprintf (sched_dump, "\n"); |
| } |
| |
| /* Returns true if all the basic blocks of the current region have |
| NOTE_DISABLE_SCHED_OF_BLOCK which means not to schedule that region. */ |
| static bool |
| sched_is_disabled_for_current_region_p (void) |
| { |
| int bb; |
| |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| if (!(BASIC_BLOCK (BB_TO_BLOCK (bb))->flags & BB_DISABLE_SCHEDULE)) |
| return false; |
| |
| return true; |
| } |
| |
| /* 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) |
| { |
| basic_block block; |
| edge_iterator ei; |
| edge e; |
| int bb; |
| int rgn_n_insns = 0; |
| int sched_rgn_n_insns = 0; |
| |
| /* Set variables for the current region. */ |
| current_nr_blocks = RGN_NR_BLOCKS (rgn); |
| current_blocks = RGN_BLOCKS (rgn); |
| |
| /* Don't schedule region that is marked by |
| NOTE_DISABLE_SCHED_OF_BLOCK. */ |
| if (sched_is_disabled_for_current_region_p ()) |
| return; |
| |
| init_deps_global (); |
| |
| /* Initializations for region data dependence analysis. */ |
| bb_deps = xmalloc (sizeof (struct deps) * current_nr_blocks); |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| init_deps (bb_deps + bb); |
| |
| /* Compute LOG_LINKS. */ |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| compute_block_backward_dependences (bb); |
| |
| /* Compute INSN_DEPEND. */ |
| for (bb = current_nr_blocks - 1; bb >= 0; bb--) |
| { |
| rtx head, tail; |
| get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); |
| |
| compute_forward_dependences (head, tail); |
| |
| if (targetm.sched.dependencies_evaluation_hook) |
| targetm.sched.dependencies_evaluation_hook (head, tail); |
| |
| } |
| |
| /* Set priorities. */ |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| { |
| rtx head, tail; |
| get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); |
| |
| rgn_n_insns += set_priorities (head, tail); |
| } |
| |
| /* Compute interblock info: probabilities, split-edges, dominators, etc. */ |
| if (current_nr_blocks > 1) |
| { |
| prob = xmalloc ((current_nr_blocks) * sizeof (float)); |
| |
| dom = sbitmap_vector_alloc (current_nr_blocks, current_nr_blocks); |
| sbitmap_vector_zero (dom, current_nr_blocks); |
| |
| /* Use ->aux to implement EDGE_TO_BIT mapping. */ |
| rgn_nr_edges = 0; |
| FOR_EACH_BB (block) |
| { |
| if (CONTAINING_RGN (block->index) != rgn) |
| continue; |
| FOR_EACH_EDGE (e, ei, block->succs) |
| SET_EDGE_TO_BIT (e, rgn_nr_edges++); |
| } |
| |
| rgn_edges = xmalloc (rgn_nr_edges * sizeof (edge)); |
| rgn_nr_edges = 0; |
| FOR_EACH_BB (block) |
| { |
| if (CONTAINING_RGN (block->index) != rgn) |
| continue; |
| FOR_EACH_EDGE (e, ei, block->succs) |
| rgn_edges[rgn_nr_edges++] = e; |
| } |
| |
| /* Split edges. */ |
| pot_split = sbitmap_vector_alloc (current_nr_blocks, rgn_nr_edges); |
| sbitmap_vector_zero (pot_split, current_nr_blocks); |
| ancestor_edges = sbitmap_vector_alloc (current_nr_blocks, rgn_nr_edges); |
| sbitmap_vector_zero (ancestor_edges, current_nr_blocks); |
| |
| /* Compute probabilities, dominators, split_edges. */ |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| compute_dom_prob_ps (bb); |
| } |
| |
| /* Now we can schedule all blocks. */ |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| { |
| rtx head, tail; |
| int b = BB_TO_BLOCK (bb); |
| |
| get_block_head_tail (b, &head, &tail); |
| |
| if (no_real_insns_p (head, tail)) |
| continue; |
| |
| current_sched_info->prev_head = PREV_INSN (head); |
| current_sched_info->next_tail = NEXT_INSN (tail); |
| |
| if (write_symbols != NO_DEBUG) |
| { |
| save_line_notes (b, head, tail); |
| rm_line_notes (head, tail); |
| } |
| |
| /* rm_other_notes only removes notes which are _inside_ the |
| block---that is, it won't remove notes before the first real insn |
| or after the last real insn of the block. So if the first insn |
| has a REG_SAVE_NOTE which would otherwise be emitted before the |
| insn, it is redundant with the note before the start of the |
| block, and so we have to take it out. */ |
| if (INSN_P (head)) |
| { |
| rtx note; |
| |
| for (note = REG_NOTES (head); note; note = XEXP (note, 1)) |
| if (REG_NOTE_KIND (note) == REG_SAVE_NOTE) |
| remove_note (head, note); |
| } |
| |
| /* Remove remaining note insns from the block, save them in |
| note_list. These notes are restored at the end of |
| schedule_block (). */ |
| rm_other_notes (head, tail); |
| |
| target_bb = bb; |
| |
| current_sched_info->queue_must_finish_empty |
| = current_nr_blocks > 1 && !flag_schedule_interblock; |
| |
| schedule_block (b, rgn_n_insns); |
| sched_rgn_n_insns += sched_n_insns; |
| |
| /* Update target block boundaries. */ |
| if (head == BB_HEAD (BASIC_BLOCK (b))) |
| BB_HEAD (BASIC_BLOCK (b)) = current_sched_info->head; |
| if (tail == BB_END (BASIC_BLOCK (b))) |
| BB_END (BASIC_BLOCK (b)) = current_sched_info->tail; |
| |
| /* Clean up. */ |
| if (current_nr_blocks > 1) |
| { |
| free (candidate_table); |
| free (bblst_table); |
| free (edgelst_table); |
| } |
| } |
| |
| /* Sanity check: verify that all region insns were scheduled. */ |
| gcc_assert (sched_rgn_n_insns == rgn_n_insns); |
| |
| /* Restore line notes. */ |
| if (write_symbols != NO_DEBUG) |
| { |
| for (bb = 0; bb < current_nr_blocks; bb++) |
| { |
| rtx head, tail; |
| get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); |
| restore_line_notes (head, tail); |
| } |
| } |
| |
| /* Done with this region. */ |
| free_pending_lists (); |
| |
| finish_deps_global (); |
| |
| free (bb_deps); |
| |
| if (current_nr_blocks > 1) |
| { |
| /* Cleanup ->aux used for EDGE_TO_BIT mapping. */ |
| FOR_EACH_BB (block) |
| { |
| if (CONTAINING_RGN (block->index) != rgn) |
| continue; |
| FOR_EACH_EDGE (e, ei, block->succs) |
| e->aux = NULL; |
| } |
| |
| free (prob); |
| sbitmap_vector_free (dom); |
| sbitmap_vector_free (pot_split); |
| sbitmap_vector_free (ancestor_edges); |
| free (rgn_edges); |
| } |
| } |
| |
| /* Indexed by region, holds the number of death notes found in that region. |
| Used for consistency checks. */ |
| static int *deaths_in_region; |
| |
| /* Initialize data structures for region scheduling. */ |
| |
| static void |
| init_regions (void) |
| { |
| sbitmap blocks; |
| int rgn; |
| |
| nr_regions = 0; |
| rgn_table = xmalloc ((n_basic_blocks) * sizeof (region)); |
| rgn_bb_table = xmalloc ((n_basic_blocks) * sizeof (int)); |
| block_to_bb = xmalloc ((last_basic_block) * sizeof (int)); |
| containing_rgn = xmalloc ((last_basic_block) * sizeof (int)); |
| |
| /* Compute regions for scheduling. */ |
| if (reload_completed |
| || n_basic_blocks == 1 |
| || !flag_schedule_interblock |
| || is_cfg_nonregular ()) |
| { |
| find_single_block_region (); |
| } |
| else |
| { |
| /* Compute the dominators and post dominators. */ |
| calculate_dominance_info (CDI_DOMINATORS); |
| |
| /* Find regions. */ |
| find_rgns (); |
| |
| if (sched_verbose >= 3) |
| debug_regions (); |
| |
| /* For now. This will move as more and more of haifa is converted |
| to using the cfg code in flow.c. */ |
| free_dominance_info (CDI_DOMINATORS); |
| } |
| |
| |
| if (CHECK_DEAD_NOTES) |
| { |
| blocks = sbitmap_alloc (last_basic_block); |
| deaths_in_region = xmalloc (sizeof (int) * nr_regions); |
| /* Remove all death notes from the subroutine. */ |
| for (rgn = 0; rgn < nr_regions; rgn++) |
| { |
| int b; |
| |
| sbitmap_zero (blocks); |
| for (b = RGN_NR_BLOCKS (rgn) - 1; b >= 0; --b) |
| SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn) + b]); |
| |
| deaths_in_region[rgn] = count_or_remove_death_notes (blocks, 1); |
| } |
| sbitmap_free (blocks); |
| } |
| else |
| count_or_remove_death_notes (NULL, 1); |
| } |
| |
| /* The one entry point in this file. DUMP_FILE is the dump file for |
| this pass. */ |
| |
| void |
| schedule_insns (FILE *dump_file) |
| { |
| sbitmap large_region_blocks, blocks; |
| int rgn; |
| int any_large_regions; |
| basic_block bb; |
| |
| /* Taking care of this degenerate case makes the rest of |
| this code simpler. */ |
| if (n_basic_blocks == 0) |
| return; |
| |
| nr_inter = 0; |
| nr_spec = 0; |
| |
| sched_init (dump_file); |
| |
| init_regions (); |
| |
| current_sched_info = ®ion_sched_info; |
| |
| /* Schedule every region in the subroutine. */ |
| for (rgn = 0; rgn < nr_regions; rgn++) |
| schedule_region (rgn); |
| |
| /* Update life analysis for the subroutine. Do single block regions |
| first so that we can verify that live_at_start didn't change. Then |
| do all other blocks. */ |
| /* ??? There is an outside possibility that update_life_info, or more |
| to the point propagate_block, could get called with nonzero flags |
| more than once for one basic block. This would be kinda bad if it |
| were to happen, since REG_INFO would be accumulated twice for the |
| block, and we'd have twice the REG_DEAD notes. |
| |
| I'm fairly certain that this _shouldn't_ happen, since I don't think |
| that live_at_start should change at region heads. Not sure what the |
| best way to test for this kind of thing... */ |
| |
| allocate_reg_life_data (); |
| compute_bb_for_insn (); |
| |
| any_large_regions = 0; |
| large_region_blocks = sbitmap_alloc (last_basic_block); |
| sbitmap_zero (large_region_blocks); |
| FOR_EACH_BB (bb) |
| SET_BIT (large_region_blocks, bb->index); |
| |
| blocks = sbitmap_alloc (last_basic_block); |
| sbitmap_zero (blocks); |
| |
| /* Update life information. For regions consisting of multiple blocks |
| we've possibly done interblock scheduling that affects global liveness. |
| For regions consisting of single blocks we need to do only local |
| liveness. */ |
| for (rgn = 0; rgn < nr_regions; rgn++) |
| if (RGN_NR_BLOCKS (rgn) > 1) |
| any_large_regions = 1; |
| else |
| { |
| SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn)]); |
| RESET_BIT (large_region_blocks, rgn_bb_table[RGN_BLOCKS (rgn)]); |
| } |
| |
| /* Don't update reg info after reload, since that affects |
| regs_ever_live, which should not change after reload. */ |
| update_life_info (blocks, UPDATE_LIFE_LOCAL, |
| (reload_completed ? PROP_DEATH_NOTES |
| : PROP_DEATH_NOTES | PROP_REG_INFO)); |
| if (any_large_regions) |
| { |
| update_life_info (large_region_blocks, UPDATE_LIFE_GLOBAL, |
| PROP_DEATH_NOTES | PROP_REG_INFO); |
| } |
| |
| if (CHECK_DEAD_NOTES) |
| { |
| /* Verify the counts of basic block notes in single the basic block |
| regions. */ |
| for (rgn = 0; rgn < nr_regions; rgn++) |
| if (RGN_NR_BLOCKS (rgn) == 1) |
| { |
| sbitmap_zero (blocks); |
| SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn)]); |
| |
| gcc_assert (deaths_in_region[rgn] |
| == count_or_remove_death_notes (blocks, 0)); |
| } |
| free (deaths_in_region); |
| } |
| |
| /* Reposition the prologue and epilogue notes in case we moved the |
| prologue/epilogue insns. */ |
| if (reload_completed) |
| reposition_prologue_and_epilogue_notes (get_insns ()); |
| |
| /* Delete redundant line notes. */ |
| if (write_symbols != NO_DEBUG) |
| rm_redundant_line_notes (); |
| |
| if (sched_verbose) |
| { |
| if (reload_completed == 0 && flag_schedule_interblock) |
| { |
| fprintf (sched_dump, |
| "\n;; Procedure interblock/speculative motions == %d/%d \n", |
| nr_inter, nr_spec); |
| } |
| else |
| gcc_assert (nr_inter <= 0); |
| fprintf (sched_dump, "\n\n"); |
| } |
| |
| /* Clean up. */ |
| free (rgn_table); |
| free (rgn_bb_table); |
| free (block_to_bb); |
| free (containing_rgn); |
| |
| sched_finish (); |
| |
| sbitmap_free (blocks); |
| sbitmap_free (large_region_blocks); |
| } |
| #endif |