| /* Loop invariant motion. |
| Copyright (C) 2003-2022 Free Software Foundation, Inc. |
| |
| 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/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "cfghooks.h" |
| #include "tree-pass.h" |
| #include "ssa.h" |
| #include "gimple-pretty-print.h" |
| #include "fold-const.h" |
| #include "cfganal.h" |
| #include "tree-eh.h" |
| #include "gimplify.h" |
| #include "gimple-iterator.h" |
| #include "tree-cfg.h" |
| #include "tree-ssa-loop-manip.h" |
| #include "tree-ssa-loop.h" |
| #include "tree-into-ssa.h" |
| #include "cfgloop.h" |
| #include "tree-affine.h" |
| #include "tree-ssa-propagate.h" |
| #include "trans-mem.h" |
| #include "gimple-fold.h" |
| #include "tree-scalar-evolution.h" |
| #include "tree-ssa-loop-niter.h" |
| #include "alias.h" |
| #include "builtins.h" |
| #include "tree-dfa.h" |
| #include "dbgcnt.h" |
| |
| /* TODO: Support for predicated code motion. I.e. |
| |
| while (1) |
| { |
| if (cond) |
| { |
| a = inv; |
| something; |
| } |
| } |
| |
| Where COND and INV are invariants, but evaluating INV may trap or be |
| invalid from some other reason if !COND. This may be transformed to |
| |
| if (cond) |
| a = inv; |
| while (1) |
| { |
| if (cond) |
| something; |
| } */ |
| |
| /* The auxiliary data kept for each statement. */ |
| |
| struct lim_aux_data |
| { |
| class loop *max_loop; /* The outermost loop in that the statement |
| is invariant. */ |
| |
| class loop *tgt_loop; /* The loop out of that we want to move the |
| invariant. */ |
| |
| class loop *always_executed_in; |
| /* The outermost loop for that we are sure |
| the statement is executed if the loop |
| is entered. */ |
| |
| unsigned cost; /* Cost of the computation performed by the |
| statement. */ |
| |
| unsigned ref; /* The simple_mem_ref in this stmt or 0. */ |
| |
| vec<gimple *> depends; /* Vector of statements that must be also |
| hoisted out of the loop when this statement |
| is hoisted; i.e. those that define the |
| operands of the statement and are inside of |
| the MAX_LOOP loop. */ |
| }; |
| |
| /* Maps statements to their lim_aux_data. */ |
| |
| static hash_map<gimple *, lim_aux_data *> *lim_aux_data_map; |
| |
| /* Description of a memory reference location. */ |
| |
| struct mem_ref_loc |
| { |
| tree *ref; /* The reference itself. */ |
| gimple *stmt; /* The statement in that it occurs. */ |
| }; |
| |
| |
| /* Description of a memory reference. */ |
| |
| class im_mem_ref |
| { |
| public: |
| unsigned id : 30; /* ID assigned to the memory reference |
| (its index in memory_accesses.refs_list) */ |
| unsigned ref_canonical : 1; /* Whether mem.ref was canonicalized. */ |
| unsigned ref_decomposed : 1; /* Whether the ref was hashed from mem. */ |
| hashval_t hash; /* Its hash value. */ |
| |
| /* The memory access itself and associated caching of alias-oracle |
| query meta-data. We are using mem.ref == error_mark_node for the |
| case the reference is represented by its single access stmt |
| in accesses_in_loop[0]. */ |
| ao_ref mem; |
| |
| bitmap stored; /* The set of loops in that this memory location |
| is stored to. */ |
| bitmap loaded; /* The set of loops in that this memory location |
| is loaded from. */ |
| vec<mem_ref_loc> accesses_in_loop; |
| /* The locations of the accesses. */ |
| |
| /* The following set is computed on demand. */ |
| bitmap_head dep_loop; /* The set of loops in that the memory |
| reference is {in,}dependent in |
| different modes. */ |
| }; |
| |
| /* We use six bits per loop in the ref->dep_loop bitmap to record |
| the dep_kind x dep_state combinations. */ |
| |
| enum dep_kind { lim_raw, sm_war, sm_waw }; |
| enum dep_state { dep_unknown, dep_independent, dep_dependent }; |
| |
| /* coldest outermost loop for given loop. */ |
| vec<class loop *> coldest_outermost_loop; |
| /* hotter outer loop nearest to given loop. */ |
| vec<class loop *> hotter_than_inner_loop; |
| |
| /* Populate the loop dependence cache of REF for LOOP, KIND with STATE. */ |
| |
| static void |
| record_loop_dependence (class loop *loop, im_mem_ref *ref, |
| dep_kind kind, dep_state state) |
| { |
| gcc_assert (state != dep_unknown); |
| unsigned bit = 6 * loop->num + kind * 2 + state == dep_dependent ? 1 : 0; |
| bitmap_set_bit (&ref->dep_loop, bit); |
| } |
| |
| /* Query the loop dependence cache of REF for LOOP, KIND. */ |
| |
| static dep_state |
| query_loop_dependence (class loop *loop, im_mem_ref *ref, dep_kind kind) |
| { |
| unsigned first_bit = 6 * loop->num + kind * 2; |
| if (bitmap_bit_p (&ref->dep_loop, first_bit)) |
| return dep_independent; |
| else if (bitmap_bit_p (&ref->dep_loop, first_bit + 1)) |
| return dep_dependent; |
| return dep_unknown; |
| } |
| |
| /* Mem_ref hashtable helpers. */ |
| |
| struct mem_ref_hasher : nofree_ptr_hash <im_mem_ref> |
| { |
| typedef ao_ref *compare_type; |
| static inline hashval_t hash (const im_mem_ref *); |
| static inline bool equal (const im_mem_ref *, const ao_ref *); |
| }; |
| |
| /* A hash function for class im_mem_ref object OBJ. */ |
| |
| inline hashval_t |
| mem_ref_hasher::hash (const im_mem_ref *mem) |
| { |
| return mem->hash; |
| } |
| |
| /* An equality function for class im_mem_ref object MEM1 with |
| memory reference OBJ2. */ |
| |
| inline bool |
| mem_ref_hasher::equal (const im_mem_ref *mem1, const ao_ref *obj2) |
| { |
| if (obj2->max_size_known_p ()) |
| return (mem1->ref_decomposed |
| && ((TREE_CODE (mem1->mem.base) == MEM_REF |
| && TREE_CODE (obj2->base) == MEM_REF |
| && operand_equal_p (TREE_OPERAND (mem1->mem.base, 0), |
| TREE_OPERAND (obj2->base, 0), 0) |
| && known_eq (mem_ref_offset (mem1->mem.base) * BITS_PER_UNIT + mem1->mem.offset, |
| mem_ref_offset (obj2->base) * BITS_PER_UNIT + obj2->offset)) |
| || (operand_equal_p (mem1->mem.base, obj2->base, 0) |
| && known_eq (mem1->mem.offset, obj2->offset))) |
| && known_eq (mem1->mem.size, obj2->size) |
| && known_eq (mem1->mem.max_size, obj2->max_size) |
| && mem1->mem.volatile_p == obj2->volatile_p |
| && (mem1->mem.ref_alias_set == obj2->ref_alias_set |
| /* We are not canonicalizing alias-sets but for the |
| special-case we didn't canonicalize yet and the |
| incoming ref is a alias-set zero MEM we pick |
| the correct one already. */ |
| || (!mem1->ref_canonical |
| && (TREE_CODE (obj2->ref) == MEM_REF |
| || TREE_CODE (obj2->ref) == TARGET_MEM_REF) |
| && obj2->ref_alias_set == 0) |
| /* Likewise if there's a canonical ref with alias-set zero. */ |
| || (mem1->ref_canonical && mem1->mem.ref_alias_set == 0)) |
| && types_compatible_p (TREE_TYPE (mem1->mem.ref), |
| TREE_TYPE (obj2->ref))); |
| else |
| return operand_equal_p (mem1->mem.ref, obj2->ref, 0); |
| } |
| |
| |
| /* Description of memory accesses in loops. */ |
| |
| static struct |
| { |
| /* The hash table of memory references accessed in loops. */ |
| hash_table<mem_ref_hasher> *refs; |
| |
| /* The list of memory references. */ |
| vec<im_mem_ref *> refs_list; |
| |
| /* The set of memory references accessed in each loop. */ |
| vec<bitmap_head> refs_loaded_in_loop; |
| |
| /* The set of memory references stored in each loop. */ |
| vec<bitmap_head> refs_stored_in_loop; |
| |
| /* The set of memory references stored in each loop, including subloops . */ |
| vec<bitmap_head> all_refs_stored_in_loop; |
| |
| /* Cache for expanding memory addresses. */ |
| hash_map<tree, name_expansion *> *ttae_cache; |
| } memory_accesses; |
| |
| /* Obstack for the bitmaps in the above data structures. */ |
| static bitmap_obstack lim_bitmap_obstack; |
| static obstack mem_ref_obstack; |
| |
| static bool ref_indep_loop_p (class loop *, im_mem_ref *, dep_kind); |
| static bool ref_always_accessed_p (class loop *, im_mem_ref *, bool); |
| static bool refs_independent_p (im_mem_ref *, im_mem_ref *, bool = true); |
| |
| /* Minimum cost of an expensive expression. */ |
| #define LIM_EXPENSIVE ((unsigned) param_lim_expensive) |
| |
| /* The outermost loop for which execution of the header guarantees that the |
| block will be executed. */ |
| #define ALWAYS_EXECUTED_IN(BB) ((class loop *) (BB)->aux) |
| #define SET_ALWAYS_EXECUTED_IN(BB, VAL) ((BB)->aux = (void *) (VAL)) |
| |
| /* ID of the shared unanalyzable mem. */ |
| #define UNANALYZABLE_MEM_ID 0 |
| |
| /* Whether the reference was analyzable. */ |
| #define MEM_ANALYZABLE(REF) ((REF)->id != UNANALYZABLE_MEM_ID) |
| |
| static struct lim_aux_data * |
| init_lim_data (gimple *stmt) |
| { |
| lim_aux_data *p = XCNEW (struct lim_aux_data); |
| lim_aux_data_map->put (stmt, p); |
| |
| return p; |
| } |
| |
| static struct lim_aux_data * |
| get_lim_data (gimple *stmt) |
| { |
| lim_aux_data **p = lim_aux_data_map->get (stmt); |
| if (!p) |
| return NULL; |
| |
| return *p; |
| } |
| |
| /* Releases the memory occupied by DATA. */ |
| |
| static void |
| free_lim_aux_data (struct lim_aux_data *data) |
| { |
| data->depends.release (); |
| free (data); |
| } |
| |
| static void |
| clear_lim_data (gimple *stmt) |
| { |
| lim_aux_data **p = lim_aux_data_map->get (stmt); |
| if (!p) |
| return; |
| |
| free_lim_aux_data (*p); |
| *p = NULL; |
| } |
| |
| |
| /* The possibilities of statement movement. */ |
| enum move_pos |
| { |
| MOVE_IMPOSSIBLE, /* No movement -- side effect expression. */ |
| MOVE_PRESERVE_EXECUTION, /* Must not cause the non-executed statement |
| become executed -- memory accesses, ... */ |
| MOVE_POSSIBLE /* Unlimited movement. */ |
| }; |
| |
| |
| /* If it is possible to hoist the statement STMT unconditionally, |
| returns MOVE_POSSIBLE. |
| If it is possible to hoist the statement STMT, but we must avoid making |
| it executed if it would not be executed in the original program (e.g. |
| because it may trap), return MOVE_PRESERVE_EXECUTION. |
| Otherwise return MOVE_IMPOSSIBLE. */ |
| |
| enum move_pos |
| movement_possibility (gimple *stmt) |
| { |
| tree lhs; |
| enum move_pos ret = MOVE_POSSIBLE; |
| |
| if (flag_unswitch_loops |
| && gimple_code (stmt) == GIMPLE_COND) |
| { |
| /* If we perform unswitching, force the operands of the invariant |
| condition to be moved out of the loop. */ |
| return MOVE_POSSIBLE; |
| } |
| |
| if (gimple_code (stmt) == GIMPLE_PHI |
| && gimple_phi_num_args (stmt) <= 2 |
| && !virtual_operand_p (gimple_phi_result (stmt)) |
| && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_phi_result (stmt))) |
| return MOVE_POSSIBLE; |
| |
| if (gimple_get_lhs (stmt) == NULL_TREE) |
| return MOVE_IMPOSSIBLE; |
| |
| if (gimple_vdef (stmt)) |
| return MOVE_IMPOSSIBLE; |
| |
| if (stmt_ends_bb_p (stmt) |
| || gimple_has_volatile_ops (stmt) |
| || gimple_has_side_effects (stmt) |
| || stmt_could_throw_p (cfun, stmt)) |
| return MOVE_IMPOSSIBLE; |
| |
| if (is_gimple_call (stmt)) |
| { |
| /* While pure or const call is guaranteed to have no side effects, we |
| cannot move it arbitrarily. Consider code like |
| |
| char *s = something (); |
| |
| while (1) |
| { |
| if (s) |
| t = strlen (s); |
| else |
| t = 0; |
| } |
| |
| Here the strlen call cannot be moved out of the loop, even though |
| s is invariant. In addition to possibly creating a call with |
| invalid arguments, moving out a function call that is not executed |
| may cause performance regressions in case the call is costly and |
| not executed at all. */ |
| ret = MOVE_PRESERVE_EXECUTION; |
| lhs = gimple_call_lhs (stmt); |
| } |
| else if (is_gimple_assign (stmt)) |
| lhs = gimple_assign_lhs (stmt); |
| else |
| return MOVE_IMPOSSIBLE; |
| |
| if (TREE_CODE (lhs) == SSA_NAME |
| && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
| return MOVE_IMPOSSIBLE; |
| |
| if (TREE_CODE (lhs) != SSA_NAME |
| || gimple_could_trap_p (stmt)) |
| return MOVE_PRESERVE_EXECUTION; |
| |
| /* Non local loads in a transaction cannot be hoisted out. Well, |
| unless the load happens on every path out of the loop, but we |
| don't take this into account yet. */ |
| if (flag_tm |
| && gimple_in_transaction (stmt) |
| && gimple_assign_single_p (stmt)) |
| { |
| tree rhs = gimple_assign_rhs1 (stmt); |
| if (DECL_P (rhs) && is_global_var (rhs)) |
| { |
| if (dump_file) |
| { |
| fprintf (dump_file, "Cannot hoist conditional load of "); |
| print_generic_expr (dump_file, rhs, TDF_SLIM); |
| fprintf (dump_file, " because it is in a transaction.\n"); |
| } |
| return MOVE_IMPOSSIBLE; |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* Compare the profile count inequality of bb and loop's preheader, it is |
| three-state as stated in profile-count.h, FALSE is returned if inequality |
| cannot be decided. */ |
| bool |
| bb_colder_than_loop_preheader (basic_block bb, class loop *loop) |
| { |
| gcc_assert (bb && loop); |
| return bb->count < loop_preheader_edge (loop)->src->count; |
| } |
| |
| /* Check coldest loop between OUTERMOST_LOOP and LOOP by comparing profile |
| count. |
| It does three steps check: |
| 1) Check whether CURR_BB is cold in it's own loop_father, if it is cold, just |
| return NULL which means it should not be moved out at all; |
| 2) CURR_BB is NOT cold, check if pre-computed COLDEST_LOOP is outside of |
| OUTERMOST_LOOP, if it is inside of OUTERMOST_LOOP, return the COLDEST_LOOP; |
| 3) If COLDEST_LOOP is outside of OUTERMOST_LOOP, check whether there is a |
| hotter loop between OUTERMOST_LOOP and loop in pre-computed |
| HOTTER_THAN_INNER_LOOP, return it's nested inner loop, otherwise return |
| OUTERMOST_LOOP. |
| At last, the coldest_loop is inside of OUTERMOST_LOOP, just return it as |
| the hoist target. */ |
| |
| static class loop * |
| get_coldest_out_loop (class loop *outermost_loop, class loop *loop, |
| basic_block curr_bb) |
| { |
| gcc_assert (outermost_loop == loop |
| || flow_loop_nested_p (outermost_loop, loop)); |
| |
| /* If bb_colder_than_loop_preheader returns false due to three-state |
| comparision, OUTERMOST_LOOP is returned finally to preserve the behavior. |
| Otherwise, return the coldest loop between OUTERMOST_LOOP and LOOP. */ |
| if (curr_bb && bb_colder_than_loop_preheader (curr_bb, loop)) |
| return NULL; |
| |
| class loop *coldest_loop = coldest_outermost_loop[loop->num]; |
| if (loop_depth (coldest_loop) < loop_depth (outermost_loop)) |
| { |
| class loop *hotter_loop = hotter_than_inner_loop[loop->num]; |
| if (!hotter_loop |
| || loop_depth (hotter_loop) < loop_depth (outermost_loop)) |
| return outermost_loop; |
| |
| /* hotter_loop is between OUTERMOST_LOOP and LOOP like: |
| [loop tree root, ..., coldest_loop, ..., outermost_loop, ..., |
| hotter_loop, second_coldest_loop, ..., loop] |
| return second_coldest_loop to be the hoist target. */ |
| class loop *aloop; |
| for (aloop = hotter_loop->inner; aloop; aloop = aloop->next) |
| if (aloop == loop || flow_loop_nested_p (aloop, loop)) |
| return aloop; |
| } |
| return coldest_loop; |
| } |
| |
| /* Suppose that operand DEF is used inside the LOOP. Returns the outermost |
| loop to that we could move the expression using DEF if it did not have |
| other operands, i.e. the outermost loop enclosing LOOP in that the value |
| of DEF is invariant. */ |
| |
| static class loop * |
| outermost_invariant_loop (tree def, class loop *loop) |
| { |
| gimple *def_stmt; |
| basic_block def_bb; |
| class loop *max_loop; |
| struct lim_aux_data *lim_data; |
| |
| if (!def) |
| return superloop_at_depth (loop, 1); |
| |
| if (TREE_CODE (def) != SSA_NAME) |
| { |
| gcc_assert (is_gimple_min_invariant (def)); |
| return superloop_at_depth (loop, 1); |
| } |
| |
| def_stmt = SSA_NAME_DEF_STMT (def); |
| def_bb = gimple_bb (def_stmt); |
| if (!def_bb) |
| return superloop_at_depth (loop, 1); |
| |
| max_loop = find_common_loop (loop, def_bb->loop_father); |
| |
| lim_data = get_lim_data (def_stmt); |
| if (lim_data != NULL && lim_data->max_loop != NULL) |
| max_loop = find_common_loop (max_loop, |
| loop_outer (lim_data->max_loop)); |
| if (max_loop == loop) |
| return NULL; |
| max_loop = superloop_at_depth (loop, loop_depth (max_loop) + 1); |
| |
| return max_loop; |
| } |
| |
| /* DATA is a structure containing information associated with a statement |
| inside LOOP. DEF is one of the operands of this statement. |
| |
| Find the outermost loop enclosing LOOP in that value of DEF is invariant |
| and record this in DATA->max_loop field. If DEF itself is defined inside |
| this loop as well (i.e. we need to hoist it out of the loop if we want |
| to hoist the statement represented by DATA), record the statement in that |
| DEF is defined to the DATA->depends list. Additionally if ADD_COST is true, |
| add the cost of the computation of DEF to the DATA->cost. |
| |
| If DEF is not invariant in LOOP, return false. Otherwise return TRUE. */ |
| |
| static bool |
| add_dependency (tree def, struct lim_aux_data *data, class loop *loop, |
| bool add_cost) |
| { |
| gimple *def_stmt = SSA_NAME_DEF_STMT (def); |
| basic_block def_bb = gimple_bb (def_stmt); |
| class loop *max_loop; |
| struct lim_aux_data *def_data; |
| |
| if (!def_bb) |
| return true; |
| |
| max_loop = outermost_invariant_loop (def, loop); |
| if (!max_loop) |
| return false; |
| |
| if (flow_loop_nested_p (data->max_loop, max_loop)) |
| data->max_loop = max_loop; |
| |
| def_data = get_lim_data (def_stmt); |
| if (!def_data) |
| return true; |
| |
| if (add_cost |
| /* Only add the cost if the statement defining DEF is inside LOOP, |
| i.e. if it is likely that by moving the invariants dependent |
| on it, we will be able to avoid creating a new register for |
| it (since it will be only used in these dependent invariants). */ |
| && def_bb->loop_father == loop) |
| data->cost += def_data->cost; |
| |
| data->depends.safe_push (def_stmt); |
| |
| return true; |
| } |
| |
| /* Returns an estimate for a cost of statement STMT. The values here |
| are just ad-hoc constants, similar to costs for inlining. */ |
| |
| static unsigned |
| stmt_cost (gimple *stmt) |
| { |
| /* Always try to create possibilities for unswitching. */ |
| if (gimple_code (stmt) == GIMPLE_COND |
| || gimple_code (stmt) == GIMPLE_PHI) |
| return LIM_EXPENSIVE; |
| |
| /* We should be hoisting calls if possible. */ |
| if (is_gimple_call (stmt)) |
| { |
| tree fndecl; |
| |
| /* Unless the call is a builtin_constant_p; this always folds to a |
| constant, so moving it is useless. */ |
| fndecl = gimple_call_fndecl (stmt); |
| if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_CONSTANT_P)) |
| return 0; |
| |
| return LIM_EXPENSIVE; |
| } |
| |
| /* Hoisting memory references out should almost surely be a win. */ |
| if (gimple_references_memory_p (stmt)) |
| return LIM_EXPENSIVE; |
| |
| if (gimple_code (stmt) != GIMPLE_ASSIGN) |
| return 1; |
| |
| switch (gimple_assign_rhs_code (stmt)) |
| { |
| case MULT_EXPR: |
| case WIDEN_MULT_EXPR: |
| case WIDEN_MULT_PLUS_EXPR: |
| case WIDEN_MULT_MINUS_EXPR: |
| case DOT_PROD_EXPR: |
| case TRUNC_DIV_EXPR: |
| case CEIL_DIV_EXPR: |
| case FLOOR_DIV_EXPR: |
| case ROUND_DIV_EXPR: |
| case EXACT_DIV_EXPR: |
| case CEIL_MOD_EXPR: |
| case FLOOR_MOD_EXPR: |
| case ROUND_MOD_EXPR: |
| case TRUNC_MOD_EXPR: |
| case RDIV_EXPR: |
| /* Division and multiplication are usually expensive. */ |
| return LIM_EXPENSIVE; |
| |
| case LSHIFT_EXPR: |
| case RSHIFT_EXPR: |
| case WIDEN_LSHIFT_EXPR: |
| case LROTATE_EXPR: |
| case RROTATE_EXPR: |
| /* Shifts and rotates are usually expensive. */ |
| return LIM_EXPENSIVE; |
| |
| case CONSTRUCTOR: |
| /* Make vector construction cost proportional to the number |
| of elements. */ |
| return CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt)); |
| |
| case SSA_NAME: |
| case PAREN_EXPR: |
| /* Whether or not something is wrapped inside a PAREN_EXPR |
| should not change move cost. Nor should an intermediate |
| unpropagated SSA name copy. */ |
| return 0; |
| |
| default: |
| return 1; |
| } |
| } |
| |
| /* Finds the outermost loop between OUTER and LOOP in that the memory reference |
| REF is independent. If REF is not independent in LOOP, NULL is returned |
| instead. */ |
| |
| static class loop * |
| outermost_indep_loop (class loop *outer, class loop *loop, im_mem_ref *ref) |
| { |
| class loop *aloop; |
| |
| if (ref->stored && bitmap_bit_p (ref->stored, loop->num)) |
| return NULL; |
| |
| for (aloop = outer; |
| aloop != loop; |
| aloop = superloop_at_depth (loop, loop_depth (aloop) + 1)) |
| if ((!ref->stored || !bitmap_bit_p (ref->stored, aloop->num)) |
| && ref_indep_loop_p (aloop, ref, lim_raw)) |
| return aloop; |
| |
| if (ref_indep_loop_p (loop, ref, lim_raw)) |
| return loop; |
| else |
| return NULL; |
| } |
| |
| /* If there is a simple load or store to a memory reference in STMT, returns |
| the location of the memory reference, and sets IS_STORE according to whether |
| it is a store or load. Otherwise, returns NULL. */ |
| |
| static tree * |
| simple_mem_ref_in_stmt (gimple *stmt, bool *is_store) |
| { |
| tree *lhs, *rhs; |
| |
| /* Recognize SSA_NAME = MEM and MEM = (SSA_NAME | invariant) patterns. */ |
| if (!gimple_assign_single_p (stmt)) |
| return NULL; |
| |
| lhs = gimple_assign_lhs_ptr (stmt); |
| rhs = gimple_assign_rhs1_ptr (stmt); |
| |
| if (TREE_CODE (*lhs) == SSA_NAME && gimple_vuse (stmt)) |
| { |
| *is_store = false; |
| return rhs; |
| } |
| else if (gimple_vdef (stmt) |
| && (TREE_CODE (*rhs) == SSA_NAME || is_gimple_min_invariant (*rhs))) |
| { |
| *is_store = true; |
| return lhs; |
| } |
| else |
| return NULL; |
| } |
| |
| /* From a controlling predicate in DOM determine the arguments from |
| the PHI node PHI that are chosen if the predicate evaluates to |
| true and false and store them to *TRUE_ARG_P and *FALSE_ARG_P if |
| they are non-NULL. Returns true if the arguments can be determined, |
| else return false. */ |
| |
| static bool |
| extract_true_false_args_from_phi (basic_block dom, gphi *phi, |
| tree *true_arg_p, tree *false_arg_p) |
| { |
| edge te, fe; |
| if (! extract_true_false_controlled_edges (dom, gimple_bb (phi), |
| &te, &fe)) |
| return false; |
| |
| if (true_arg_p) |
| *true_arg_p = PHI_ARG_DEF (phi, te->dest_idx); |
| if (false_arg_p) |
| *false_arg_p = PHI_ARG_DEF (phi, fe->dest_idx); |
| |
| return true; |
| } |
| |
| /* Determine the outermost loop to that it is possible to hoist a statement |
| STMT and store it to LIM_DATA (STMT)->max_loop. To do this we determine |
| the outermost loop in that the value computed by STMT is invariant. |
| If MUST_PRESERVE_EXEC is true, additionally choose such a loop that |
| we preserve the fact whether STMT is executed. It also fills other related |
| information to LIM_DATA (STMT). |
| |
| The function returns false if STMT cannot be hoisted outside of the loop it |
| is defined in, and true otherwise. */ |
| |
| static bool |
| determine_max_movement (gimple *stmt, bool must_preserve_exec) |
| { |
| basic_block bb = gimple_bb (stmt); |
| class loop *loop = bb->loop_father; |
| class loop *level; |
| struct lim_aux_data *lim_data = get_lim_data (stmt); |
| tree val; |
| ssa_op_iter iter; |
| |
| if (must_preserve_exec) |
| level = ALWAYS_EXECUTED_IN (bb); |
| else |
| level = superloop_at_depth (loop, 1); |
| lim_data->max_loop = get_coldest_out_loop (level, loop, bb); |
| if (!lim_data->max_loop) |
| return false; |
| |
| if (gphi *phi = dyn_cast <gphi *> (stmt)) |
| { |
| use_operand_p use_p; |
| unsigned min_cost = UINT_MAX; |
| unsigned total_cost = 0; |
| struct lim_aux_data *def_data; |
| |
| /* We will end up promoting dependencies to be unconditionally |
| evaluated. For this reason the PHI cost (and thus the |
| cost we remove from the loop by doing the invariant motion) |
| is that of the cheapest PHI argument dependency chain. */ |
| FOR_EACH_PHI_ARG (use_p, phi, iter, SSA_OP_USE) |
| { |
| val = USE_FROM_PTR (use_p); |
| |
| if (TREE_CODE (val) != SSA_NAME) |
| { |
| /* Assign const 1 to constants. */ |
| min_cost = MIN (min_cost, 1); |
| total_cost += 1; |
| continue; |
| } |
| if (!add_dependency (val, lim_data, loop, false)) |
| return false; |
| |
| gimple *def_stmt = SSA_NAME_DEF_STMT (val); |
| if (gimple_bb (def_stmt) |
| && gimple_bb (def_stmt)->loop_father == loop) |
| { |
| def_data = get_lim_data (def_stmt); |
| if (def_data) |
| { |
| min_cost = MIN (min_cost, def_data->cost); |
| total_cost += def_data->cost; |
| } |
| } |
| } |
| |
| min_cost = MIN (min_cost, total_cost); |
| lim_data->cost += min_cost; |
| |
| if (gimple_phi_num_args (phi) > 1) |
| { |
| basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb); |
| gimple *cond; |
| if (gsi_end_p (gsi_last_bb (dom))) |
| return false; |
| cond = gsi_stmt (gsi_last_bb (dom)); |
| if (gimple_code (cond) != GIMPLE_COND) |
| return false; |
| /* Verify that this is an extended form of a diamond and |
| the PHI arguments are completely controlled by the |
| predicate in DOM. */ |
| if (!extract_true_false_args_from_phi (dom, phi, NULL, NULL)) |
| return false; |
| |
| /* Fold in dependencies and cost of the condition. */ |
| FOR_EACH_SSA_TREE_OPERAND (val, cond, iter, SSA_OP_USE) |
| { |
| if (!add_dependency (val, lim_data, loop, false)) |
| return false; |
| def_data = get_lim_data (SSA_NAME_DEF_STMT (val)); |
| if (def_data) |
| lim_data->cost += def_data->cost; |
| } |
| |
| /* We want to avoid unconditionally executing very expensive |
| operations. As costs for our dependencies cannot be |
| negative just claim we are not invariand for this case. |
| We also are not sure whether the control-flow inside the |
| loop will vanish. */ |
| if (total_cost - min_cost >= 2 * LIM_EXPENSIVE |
| && !(min_cost != 0 |
| && total_cost / min_cost <= 2)) |
| return false; |
| |
| /* Assume that the control-flow in the loop will vanish. |
| ??? We should verify this and not artificially increase |
| the cost if that is not the case. */ |
| lim_data->cost += stmt_cost (stmt); |
| } |
| |
| return true; |
| } |
| else |
| FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_USE) |
| if (!add_dependency (val, lim_data, loop, true)) |
| return false; |
| |
| if (gimple_vuse (stmt)) |
| { |
| im_mem_ref *ref |
| = lim_data ? memory_accesses.refs_list[lim_data->ref] : NULL; |
| if (ref |
| && MEM_ANALYZABLE (ref)) |
| { |
| lim_data->max_loop = outermost_indep_loop (lim_data->max_loop, |
| loop, ref); |
| if (!lim_data->max_loop) |
| return false; |
| } |
| else if (! add_dependency (gimple_vuse (stmt), lim_data, loop, false)) |
| return false; |
| } |
| |
| lim_data->cost += stmt_cost (stmt); |
| |
| return true; |
| } |
| |
| /* Suppose that some statement in ORIG_LOOP is hoisted to the loop LEVEL, |
| and that one of the operands of this statement is computed by STMT. |
| Ensure that STMT (together with all the statements that define its |
| operands) is hoisted at least out of the loop LEVEL. */ |
| |
| static void |
| set_level (gimple *stmt, class loop *orig_loop, class loop *level) |
| { |
| class loop *stmt_loop = gimple_bb (stmt)->loop_father; |
| struct lim_aux_data *lim_data; |
| gimple *dep_stmt; |
| unsigned i; |
| |
| stmt_loop = find_common_loop (orig_loop, stmt_loop); |
| lim_data = get_lim_data (stmt); |
| if (lim_data != NULL && lim_data->tgt_loop != NULL) |
| stmt_loop = find_common_loop (stmt_loop, |
| loop_outer (lim_data->tgt_loop)); |
| if (flow_loop_nested_p (stmt_loop, level)) |
| return; |
| |
| gcc_assert (level == lim_data->max_loop |
| || flow_loop_nested_p (lim_data->max_loop, level)); |
| |
| lim_data->tgt_loop = level; |
| FOR_EACH_VEC_ELT (lim_data->depends, i, dep_stmt) |
| set_level (dep_stmt, orig_loop, level); |
| } |
| |
| /* Determines an outermost loop from that we want to hoist the statement STMT. |
| For now we chose the outermost possible loop. TODO -- use profiling |
| information to set it more sanely. */ |
| |
| static void |
| set_profitable_level (gimple *stmt) |
| { |
| set_level (stmt, gimple_bb (stmt)->loop_father, get_lim_data (stmt)->max_loop); |
| } |
| |
| /* Returns true if STMT is a call that has side effects. */ |
| |
| static bool |
| nonpure_call_p (gimple *stmt) |
| { |
| if (gimple_code (stmt) != GIMPLE_CALL) |
| return false; |
| |
| return gimple_has_side_effects (stmt); |
| } |
| |
| /* Rewrite a/b to a*(1/b). Return the invariant stmt to process. */ |
| |
| static gimple * |
| rewrite_reciprocal (gimple_stmt_iterator *bsi) |
| { |
| gassign *stmt, *stmt1, *stmt2; |
| tree name, lhs, type; |
| tree real_one; |
| gimple_stmt_iterator gsi; |
| |
| stmt = as_a <gassign *> (gsi_stmt (*bsi)); |
| lhs = gimple_assign_lhs (stmt); |
| type = TREE_TYPE (lhs); |
| |
| real_one = build_one_cst (type); |
| |
| name = make_temp_ssa_name (type, NULL, "reciptmp"); |
| stmt1 = gimple_build_assign (name, RDIV_EXPR, real_one, |
| gimple_assign_rhs2 (stmt)); |
| stmt2 = gimple_build_assign (lhs, MULT_EXPR, name, |
| gimple_assign_rhs1 (stmt)); |
| |
| /* Replace division stmt with reciprocal and multiply stmts. |
| The multiply stmt is not invariant, so update iterator |
| and avoid rescanning. */ |
| gsi = *bsi; |
| gsi_insert_before (bsi, stmt1, GSI_NEW_STMT); |
| gsi_replace (&gsi, stmt2, true); |
| |
| /* Continue processing with invariant reciprocal statement. */ |
| return stmt1; |
| } |
| |
| /* Check if the pattern at *BSI is a bittest of the form |
| (A >> B) & 1 != 0 and in this case rewrite it to A & (1 << B) != 0. */ |
| |
| static gimple * |
| rewrite_bittest (gimple_stmt_iterator *bsi) |
| { |
| gassign *stmt; |
| gimple *stmt1; |
| gassign *stmt2; |
| gimple *use_stmt; |
| gcond *cond_stmt; |
| tree lhs, name, t, a, b; |
| use_operand_p use; |
| |
| stmt = as_a <gassign *> (gsi_stmt (*bsi)); |
| lhs = gimple_assign_lhs (stmt); |
| |
| /* Verify that the single use of lhs is a comparison against zero. */ |
| if (TREE_CODE (lhs) != SSA_NAME |
| || !single_imm_use (lhs, &use, &use_stmt)) |
| return stmt; |
| cond_stmt = dyn_cast <gcond *> (use_stmt); |
| if (!cond_stmt) |
| return stmt; |
| if (gimple_cond_lhs (cond_stmt) != lhs |
| || (gimple_cond_code (cond_stmt) != NE_EXPR |
| && gimple_cond_code (cond_stmt) != EQ_EXPR) |
| || !integer_zerop (gimple_cond_rhs (cond_stmt))) |
| return stmt; |
| |
| /* Get at the operands of the shift. The rhs is TMP1 & 1. */ |
| stmt1 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt)); |
| if (gimple_code (stmt1) != GIMPLE_ASSIGN) |
| return stmt; |
| |
| /* There is a conversion in between possibly inserted by fold. */ |
| if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt1))) |
| { |
| t = gimple_assign_rhs1 (stmt1); |
| if (TREE_CODE (t) != SSA_NAME |
| || !has_single_use (t)) |
| return stmt; |
| stmt1 = SSA_NAME_DEF_STMT (t); |
| if (gimple_code (stmt1) != GIMPLE_ASSIGN) |
| return stmt; |
| } |
| |
| /* Verify that B is loop invariant but A is not. Verify that with |
| all the stmt walking we are still in the same loop. */ |
| if (gimple_assign_rhs_code (stmt1) != RSHIFT_EXPR |
| || loop_containing_stmt (stmt1) != loop_containing_stmt (stmt)) |
| return stmt; |
| |
| a = gimple_assign_rhs1 (stmt1); |
| b = gimple_assign_rhs2 (stmt1); |
| |
| if (outermost_invariant_loop (b, loop_containing_stmt (stmt1)) != NULL |
| && outermost_invariant_loop (a, loop_containing_stmt (stmt1)) == NULL) |
| { |
| gimple_stmt_iterator rsi; |
| |
| /* 1 << B */ |
| t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (a), |
| build_int_cst (TREE_TYPE (a), 1), b); |
| name = make_temp_ssa_name (TREE_TYPE (a), NULL, "shifttmp"); |
| stmt1 = gimple_build_assign (name, t); |
| |
| /* A & (1 << B) */ |
| t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (a), a, name); |
| name = make_temp_ssa_name (TREE_TYPE (a), NULL, "shifttmp"); |
| stmt2 = gimple_build_assign (name, t); |
| |
| /* Replace the SSA_NAME we compare against zero. Adjust |
| the type of zero accordingly. */ |
| SET_USE (use, name); |
| gimple_cond_set_rhs (cond_stmt, |
| build_int_cst_type (TREE_TYPE (name), |
| 0)); |
| |
| /* Don't use gsi_replace here, none of the new assignments sets |
| the variable originally set in stmt. Move bsi to stmt1, and |
| then remove the original stmt, so that we get a chance to |
| retain debug info for it. */ |
| rsi = *bsi; |
| gsi_insert_before (bsi, stmt1, GSI_NEW_STMT); |
| gsi_insert_before (&rsi, stmt2, GSI_SAME_STMT); |
| gimple *to_release = gsi_stmt (rsi); |
| gsi_remove (&rsi, true); |
| release_defs (to_release); |
| |
| return stmt1; |
| } |
| |
| return stmt; |
| } |
| |
| /* Determine the outermost loops in that statements in basic block BB are |
| invariant, and record them to the LIM_DATA associated with the |
| statements. */ |
| |
| static void |
| compute_invariantness (basic_block bb) |
| { |
| enum move_pos pos; |
| gimple_stmt_iterator bsi; |
| gimple *stmt; |
| bool maybe_never = ALWAYS_EXECUTED_IN (bb) == NULL; |
| class loop *outermost = ALWAYS_EXECUTED_IN (bb); |
| struct lim_aux_data *lim_data; |
| |
| if (!loop_outer (bb->loop_father)) |
| return; |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "Basic block %d (loop %d -- depth %d):\n\n", |
| bb->index, bb->loop_father->num, loop_depth (bb->loop_father)); |
| |
| /* Look at PHI nodes, but only if there is at most two. |
| ??? We could relax this further by post-processing the inserted |
| code and transforming adjacent cond-exprs with the same predicate |
| to control flow again. */ |
| bsi = gsi_start_phis (bb); |
| if (!gsi_end_p (bsi) |
| && ((gsi_next (&bsi), gsi_end_p (bsi)) |
| || (gsi_next (&bsi), gsi_end_p (bsi)))) |
| for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
| { |
| stmt = gsi_stmt (bsi); |
| |
| pos = movement_possibility (stmt); |
| if (pos == MOVE_IMPOSSIBLE) |
| continue; |
| |
| lim_data = get_lim_data (stmt); |
| if (! lim_data) |
| lim_data = init_lim_data (stmt); |
| lim_data->always_executed_in = outermost; |
| |
| if (!determine_max_movement (stmt, false)) |
| { |
| lim_data->max_loop = NULL; |
| continue; |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| print_gimple_stmt (dump_file, stmt, 2); |
| fprintf (dump_file, " invariant up to level %d, cost %d.\n\n", |
| loop_depth (lim_data->max_loop), |
| lim_data->cost); |
| } |
| |
| if (lim_data->cost >= LIM_EXPENSIVE) |
| set_profitable_level (stmt); |
| } |
| |
| for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
| { |
| stmt = gsi_stmt (bsi); |
| |
| pos = movement_possibility (stmt); |
| if (pos == MOVE_IMPOSSIBLE) |
| { |
| if (nonpure_call_p (stmt)) |
| { |
| maybe_never = true; |
| outermost = NULL; |
| } |
| /* Make sure to note always_executed_in for stores to make |
| store-motion work. */ |
| else if (stmt_makes_single_store (stmt)) |
| { |
| struct lim_aux_data *lim_data = get_lim_data (stmt); |
| if (! lim_data) |
| lim_data = init_lim_data (stmt); |
| lim_data->always_executed_in = outermost; |
| } |
| continue; |
| } |
| |
| if (is_gimple_assign (stmt) |
| && (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) |
| == GIMPLE_BINARY_RHS)) |
| { |
| tree op0 = gimple_assign_rhs1 (stmt); |
| tree op1 = gimple_assign_rhs2 (stmt); |
| class loop *ol1 = outermost_invariant_loop (op1, |
| loop_containing_stmt (stmt)); |
| |
| /* If divisor is invariant, convert a/b to a*(1/b), allowing reciprocal |
| to be hoisted out of loop, saving expensive divide. */ |
| if (pos == MOVE_POSSIBLE |
| && gimple_assign_rhs_code (stmt) == RDIV_EXPR |
| && flag_unsafe_math_optimizations |
| && !flag_trapping_math |
| && ol1 != NULL |
| && outermost_invariant_loop (op0, ol1) == NULL) |
| stmt = rewrite_reciprocal (&bsi); |
| |
| /* If the shift count is invariant, convert (A >> B) & 1 to |
| A & (1 << B) allowing the bit mask to be hoisted out of the loop |
| saving an expensive shift. */ |
| if (pos == MOVE_POSSIBLE |
| && gimple_assign_rhs_code (stmt) == BIT_AND_EXPR |
| && integer_onep (op1) |
| && TREE_CODE (op0) == SSA_NAME |
| && has_single_use (op0)) |
| stmt = rewrite_bittest (&bsi); |
| } |
| |
| lim_data = get_lim_data (stmt); |
| if (! lim_data) |
| lim_data = init_lim_data (stmt); |
| lim_data->always_executed_in = outermost; |
| |
| if (maybe_never && pos == MOVE_PRESERVE_EXECUTION) |
| continue; |
| |
| if (!determine_max_movement (stmt, pos == MOVE_PRESERVE_EXECUTION)) |
| { |
| lim_data->max_loop = NULL; |
| continue; |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| print_gimple_stmt (dump_file, stmt, 2); |
| fprintf (dump_file, " invariant up to level %d, cost %d.\n\n", |
| loop_depth (lim_data->max_loop), |
| lim_data->cost); |
| } |
| |
| if (lim_data->cost >= LIM_EXPENSIVE) |
| set_profitable_level (stmt); |
| } |
| } |
| |
| /* Hoist the statements in basic block BB out of the loops prescribed by |
| data stored in LIM_DATA structures associated with each statement. Callback |
| for walk_dominator_tree. */ |
| |
| unsigned int |
| move_computations_worker (basic_block bb) |
| { |
| class loop *level; |
| unsigned cost = 0; |
| struct lim_aux_data *lim_data; |
| unsigned int todo = 0; |
| |
| if (!loop_outer (bb->loop_father)) |
| return todo; |
| |
| for (gphi_iterator bsi = gsi_start_phis (bb); !gsi_end_p (bsi); ) |
| { |
| gassign *new_stmt; |
| gphi *stmt = bsi.phi (); |
| |
| lim_data = get_lim_data (stmt); |
| if (lim_data == NULL) |
| { |
| gsi_next (&bsi); |
| continue; |
| } |
| |
| cost = lim_data->cost; |
| level = lim_data->tgt_loop; |
| clear_lim_data (stmt); |
| |
| if (!level) |
| { |
| gsi_next (&bsi); |
| continue; |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Moving PHI node\n"); |
| print_gimple_stmt (dump_file, stmt, 0); |
| fprintf (dump_file, "(cost %u) out of loop %d.\n\n", |
| cost, level->num); |
| } |
| |
| if (gimple_phi_num_args (stmt) == 1) |
| { |
| tree arg = PHI_ARG_DEF (stmt, 0); |
| new_stmt = gimple_build_assign (gimple_phi_result (stmt), |
| TREE_CODE (arg), arg); |
| } |
| else |
| { |
| basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb); |
| gimple *cond = gsi_stmt (gsi_last_bb (dom)); |
| tree arg0 = NULL_TREE, arg1 = NULL_TREE, t; |
| /* Get the PHI arguments corresponding to the true and false |
| edges of COND. */ |
| extract_true_false_args_from_phi (dom, stmt, &arg0, &arg1); |
| gcc_assert (arg0 && arg1); |
| t = build2 (gimple_cond_code (cond), boolean_type_node, |
| gimple_cond_lhs (cond), gimple_cond_rhs (cond)); |
| new_stmt = gimple_build_assign (gimple_phi_result (stmt), |
| COND_EXPR, t, arg0, arg1); |
| todo |= TODO_cleanup_cfg; |
| } |
| if (!ALWAYS_EXECUTED_IN (bb) |
| || (ALWAYS_EXECUTED_IN (bb) != level |
| && !flow_loop_nested_p (ALWAYS_EXECUTED_IN (bb), level))) |
| reset_flow_sensitive_info (gimple_assign_lhs (new_stmt)); |
| gsi_insert_on_edge (loop_preheader_edge (level), new_stmt); |
| remove_phi_node (&bsi, false); |
| } |
| |
| for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi); ) |
| { |
| edge e; |
| |
| gimple *stmt = gsi_stmt (bsi); |
| |
| lim_data = get_lim_data (stmt); |
| if (lim_data == NULL) |
| { |
| gsi_next (&bsi); |
| continue; |
| } |
| |
| cost = lim_data->cost; |
| level = lim_data->tgt_loop; |
| clear_lim_data (stmt); |
| |
| if (!level) |
| { |
| gsi_next (&bsi); |
| continue; |
| } |
| |
| /* We do not really want to move conditionals out of the loop; we just |
| placed it here to force its operands to be moved if necessary. */ |
| if (gimple_code (stmt) == GIMPLE_COND) |
| { |
| gsi_next (&bsi); |
| continue; |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Moving statement\n"); |
| print_gimple_stmt (dump_file, stmt, 0); |
| fprintf (dump_file, "(cost %u) out of loop %d.\n\n", |
| cost, level->num); |
| } |
| |
| e = loop_preheader_edge (level); |
| gcc_assert (!gimple_vdef (stmt)); |
| if (gimple_vuse (stmt)) |
| { |
| /* The new VUSE is the one from the virtual PHI in the loop |
| header or the one already present. */ |
| gphi_iterator gsi2; |
| for (gsi2 = gsi_start_phis (e->dest); |
| !gsi_end_p (gsi2); gsi_next (&gsi2)) |
| { |
| gphi *phi = gsi2.phi (); |
| if (virtual_operand_p (gimple_phi_result (phi))) |
| { |
| SET_USE (gimple_vuse_op (stmt), |
| PHI_ARG_DEF_FROM_EDGE (phi, e)); |
| break; |
| } |
| } |
| } |
| gsi_remove (&bsi, false); |
| if (gimple_has_lhs (stmt) |
| && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME |
| && (!ALWAYS_EXECUTED_IN (bb) |
| || !(ALWAYS_EXECUTED_IN (bb) == level |
| || flow_loop_nested_p (ALWAYS_EXECUTED_IN (bb), level)))) |
| reset_flow_sensitive_info (gimple_get_lhs (stmt)); |
| /* In case this is a stmt that is not unconditionally executed |
| when the target loop header is executed and the stmt may |
| invoke undefined integer or pointer overflow rewrite it to |
| unsigned arithmetic. */ |
| if (is_gimple_assign (stmt) |
| && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (stmt))) |
| && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (gimple_assign_lhs (stmt))) |
| && arith_code_with_undefined_signed_overflow |
| (gimple_assign_rhs_code (stmt)) |
| && (!ALWAYS_EXECUTED_IN (bb) |
| || !(ALWAYS_EXECUTED_IN (bb) == level |
| || flow_loop_nested_p (ALWAYS_EXECUTED_IN (bb), level)))) |
| gsi_insert_seq_on_edge (e, rewrite_to_defined_overflow (stmt)); |
| else |
| gsi_insert_on_edge (e, stmt); |
| } |
| |
| return todo; |
| } |
| |
| /* Checks whether the statement defining variable *INDEX can be hoisted |
| out of the loop passed in DATA. Callback for for_each_index. */ |
| |
| static bool |
| may_move_till (tree ref, tree *index, void *data) |
| { |
| class loop *loop = (class loop *) data, *max_loop; |
| |
| /* If REF is an array reference, check also that the step and the lower |
| bound is invariant in LOOP. */ |
| if (TREE_CODE (ref) == ARRAY_REF) |
| { |
| tree step = TREE_OPERAND (ref, 3); |
| tree lbound = TREE_OPERAND (ref, 2); |
| |
| max_loop = outermost_invariant_loop (step, loop); |
| if (!max_loop) |
| return false; |
| |
| max_loop = outermost_invariant_loop (lbound, loop); |
| if (!max_loop) |
| return false; |
| } |
| |
| max_loop = outermost_invariant_loop (*index, loop); |
| if (!max_loop) |
| return false; |
| |
| return true; |
| } |
| |
| /* If OP is SSA NAME, force the statement that defines it to be |
| moved out of the LOOP. ORIG_LOOP is the loop in that EXPR is used. */ |
| |
| static void |
| force_move_till_op (tree op, class loop *orig_loop, class loop *loop) |
| { |
| gimple *stmt; |
| |
| if (!op |
| || is_gimple_min_invariant (op)) |
| return; |
| |
| gcc_assert (TREE_CODE (op) == SSA_NAME); |
| |
| stmt = SSA_NAME_DEF_STMT (op); |
| if (gimple_nop_p (stmt)) |
| return; |
| |
| set_level (stmt, orig_loop, loop); |
| } |
| |
| /* Forces statement defining invariants in REF (and *INDEX) to be moved out of |
| the LOOP. The reference REF is used in the loop ORIG_LOOP. Callback for |
| for_each_index. */ |
| |
| struct fmt_data |
| { |
| class loop *loop; |
| class loop *orig_loop; |
| }; |
| |
| static bool |
| force_move_till (tree ref, tree *index, void *data) |
| { |
| struct fmt_data *fmt_data = (struct fmt_data *) data; |
| |
| if (TREE_CODE (ref) == ARRAY_REF) |
| { |
| tree step = TREE_OPERAND (ref, 3); |
| tree lbound = TREE_OPERAND (ref, 2); |
| |
| force_move_till_op (step, fmt_data->orig_loop, fmt_data->loop); |
| force_move_till_op (lbound, fmt_data->orig_loop, fmt_data->loop); |
| } |
| |
| force_move_till_op (*index, fmt_data->orig_loop, fmt_data->loop); |
| |
| return true; |
| } |
| |
| /* A function to free the mem_ref object OBJ. */ |
| |
| static void |
| memref_free (class im_mem_ref *mem) |
| { |
| mem->accesses_in_loop.release (); |
| } |
| |
| /* Allocates and returns a memory reference description for MEM whose hash |
| value is HASH and id is ID. */ |
| |
| static im_mem_ref * |
| mem_ref_alloc (ao_ref *mem, unsigned hash, unsigned id) |
| { |
| im_mem_ref *ref = XOBNEW (&mem_ref_obstack, class im_mem_ref); |
| if (mem) |
| ref->mem = *mem; |
| else |
| ao_ref_init (&ref->mem, error_mark_node); |
| ref->id = id; |
| ref->ref_canonical = false; |
| ref->ref_decomposed = false; |
| ref->hash = hash; |
| ref->stored = NULL; |
| ref->loaded = NULL; |
| bitmap_initialize (&ref->dep_loop, &lim_bitmap_obstack); |
| ref->accesses_in_loop.create (1); |
| |
| return ref; |
| } |
| |
| /* Records memory reference location *LOC in LOOP to the memory reference |
| description REF. The reference occurs in statement STMT. */ |
| |
| static void |
| record_mem_ref_loc (im_mem_ref *ref, gimple *stmt, tree *loc) |
| { |
| mem_ref_loc aref; |
| aref.stmt = stmt; |
| aref.ref = loc; |
| ref->accesses_in_loop.safe_push (aref); |
| } |
| |
| /* Set the LOOP bit in REF stored bitmap and allocate that if |
| necessary. Return whether a bit was changed. */ |
| |
| static bool |
| set_ref_stored_in_loop (im_mem_ref *ref, class loop *loop) |
| { |
| if (!ref->stored) |
| ref->stored = BITMAP_ALLOC (&lim_bitmap_obstack); |
| return bitmap_set_bit (ref->stored, loop->num); |
| } |
| |
| /* Marks reference REF as stored in LOOP. */ |
| |
| static void |
| mark_ref_stored (im_mem_ref *ref, class loop *loop) |
| { |
| while (loop != current_loops->tree_root |
| && set_ref_stored_in_loop (ref, loop)) |
| loop = loop_outer (loop); |
| } |
| |
| /* Set the LOOP bit in REF loaded bitmap and allocate that if |
| necessary. Return whether a bit was changed. */ |
| |
| static bool |
| set_ref_loaded_in_loop (im_mem_ref *ref, class loop *loop) |
| { |
| if (!ref->loaded) |
| ref->loaded = BITMAP_ALLOC (&lim_bitmap_obstack); |
| return bitmap_set_bit (ref->loaded, loop->num); |
| } |
| |
| /* Marks reference REF as loaded in LOOP. */ |
| |
| static void |
| mark_ref_loaded (im_mem_ref *ref, class loop *loop) |
| { |
| while (loop != current_loops->tree_root |
| && set_ref_loaded_in_loop (ref, loop)) |
| loop = loop_outer (loop); |
| } |
| |
| /* Gathers memory references in statement STMT in LOOP, storing the |
| information about them in the memory_accesses structure. Marks |
| the vops accessed through unrecognized statements there as |
| well. */ |
| |
| static void |
| gather_mem_refs_stmt (class loop *loop, gimple *stmt) |
| { |
| tree *mem = NULL; |
| hashval_t hash; |
| im_mem_ref **slot; |
| im_mem_ref *ref; |
| bool is_stored; |
| unsigned id; |
| |
| if (!gimple_vuse (stmt)) |
| return; |
| |
| mem = simple_mem_ref_in_stmt (stmt, &is_stored); |
| if (!mem && is_gimple_assign (stmt)) |
| { |
| /* For aggregate copies record distinct references but use them |
| only for disambiguation purposes. */ |
| id = memory_accesses.refs_list.length (); |
| ref = mem_ref_alloc (NULL, 0, id); |
| memory_accesses.refs_list.safe_push (ref); |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Unhandled memory reference %u: ", id); |
| print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
| } |
| record_mem_ref_loc (ref, stmt, mem); |
| is_stored = gimple_vdef (stmt); |
| } |
| else if (!mem) |
| { |
| /* We use the shared mem_ref for all unanalyzable refs. */ |
| id = UNANALYZABLE_MEM_ID; |
| ref = memory_accesses.refs_list[id]; |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Unanalyzed memory reference %u: ", id); |
| print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
| } |
| is_stored = gimple_vdef (stmt); |
| } |
| else |
| { |
| /* We are looking for equal refs that might differ in structure |
| such as a.b vs. MEM[&a + 4]. So we key off the ao_ref but |
| make sure we can canonicalize the ref in the hashtable if |
| non-operand_equal_p refs are found. For the lookup we mark |
| the case we want strict equality with aor.max_size == -1. */ |
| ao_ref aor; |
| ao_ref_init (&aor, *mem); |
| ao_ref_base (&aor); |
| ao_ref_alias_set (&aor); |
| HOST_WIDE_INT offset, size, max_size; |
| poly_int64 saved_maxsize = aor.max_size, mem_off; |
| tree mem_base; |
| bool ref_decomposed; |
| if (aor.max_size_known_p () |
| && aor.offset.is_constant (&offset) |
| && aor.size.is_constant (&size) |
| && aor.max_size.is_constant (&max_size) |
| && size == max_size |
| && (size % BITS_PER_UNIT) == 0 |
| /* We're canonicalizing to a MEM where TYPE_SIZE specifies the |
| size. Make sure this is consistent with the extraction. */ |
| && poly_int_tree_p (TYPE_SIZE (TREE_TYPE (*mem))) |
| && known_eq (wi::to_poly_offset (TYPE_SIZE (TREE_TYPE (*mem))), |
| aor.size) |
| && (mem_base = get_addr_base_and_unit_offset (aor.ref, &mem_off))) |
| { |
| ref_decomposed = true; |
| tree base = ao_ref_base (&aor); |
| poly_int64 moffset; |
| HOST_WIDE_INT mcoffset; |
| if (TREE_CODE (base) == MEM_REF |
| && (mem_ref_offset (base) * BITS_PER_UNIT + offset).to_shwi (&moffset) |
| && moffset.is_constant (&mcoffset)) |
| { |
| hash = iterative_hash_expr (TREE_OPERAND (base, 0), 0); |
| hash = iterative_hash_host_wide_int (mcoffset, hash); |
| } |
| else |
| { |
| hash = iterative_hash_expr (base, 0); |
| hash = iterative_hash_host_wide_int (offset, hash); |
| } |
| hash = iterative_hash_host_wide_int (size, hash); |
| } |
| else |
| { |
| ref_decomposed = false; |
| hash = iterative_hash_expr (aor.ref, 0); |
| aor.max_size = -1; |
| } |
| slot = memory_accesses.refs->find_slot_with_hash (&aor, hash, INSERT); |
| aor.max_size = saved_maxsize; |
| if (*slot) |
| { |
| if (!(*slot)->ref_canonical |
| && !operand_equal_p (*mem, (*slot)->mem.ref, 0)) |
| { |
| /* If we didn't yet canonicalize the hashtable ref (which |
| we'll end up using for code insertion) and hit a second |
| equal ref that is not structurally equivalent create |
| a canonical ref which is a bare MEM_REF. */ |
| if (TREE_CODE (*mem) == MEM_REF |
| || TREE_CODE (*mem) == TARGET_MEM_REF) |
| { |
| (*slot)->mem.ref = *mem; |
| (*slot)->mem.base_alias_set = ao_ref_base_alias_set (&aor); |
| } |
| else |
| { |
| tree ref_alias_type = reference_alias_ptr_type (*mem); |
| unsigned int ref_align = get_object_alignment (*mem); |
| tree ref_type = TREE_TYPE (*mem); |
| tree tmp = build1 (ADDR_EXPR, ptr_type_node, |
| unshare_expr (mem_base)); |
| if (TYPE_ALIGN (ref_type) != ref_align) |
| ref_type = build_aligned_type (ref_type, ref_align); |
| (*slot)->mem.ref |
| = fold_build2 (MEM_REF, ref_type, tmp, |
| build_int_cst (ref_alias_type, mem_off)); |
| if ((*slot)->mem.volatile_p) |
| TREE_THIS_VOLATILE ((*slot)->mem.ref) = 1; |
| gcc_checking_assert (TREE_CODE ((*slot)->mem.ref) == MEM_REF |
| && is_gimple_mem_ref_addr |
| (TREE_OPERAND ((*slot)->mem.ref, |
| 0))); |
| (*slot)->mem.base_alias_set = (*slot)->mem.ref_alias_set; |
| } |
| (*slot)->ref_canonical = true; |
| } |
| ref = *slot; |
| id = ref->id; |
| } |
| else |
| { |
| id = memory_accesses.refs_list.length (); |
| ref = mem_ref_alloc (&aor, hash, id); |
| ref->ref_decomposed = ref_decomposed; |
| memory_accesses.refs_list.safe_push (ref); |
| *slot = ref; |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Memory reference %u: ", id); |
| print_generic_expr (dump_file, ref->mem.ref, TDF_SLIM); |
| fprintf (dump_file, "\n"); |
| } |
| } |
| |
| record_mem_ref_loc (ref, stmt, mem); |
| } |
| if (is_stored) |
| { |
| bitmap_set_bit (&memory_accesses.refs_stored_in_loop[loop->num], ref->id); |
| mark_ref_stored (ref, loop); |
| } |
| /* A not simple memory op is also a read when it is a write. */ |
| if (!is_stored || id == UNANALYZABLE_MEM_ID |
| || ref->mem.ref == error_mark_node) |
| { |
| bitmap_set_bit (&memory_accesses.refs_loaded_in_loop[loop->num], ref->id); |
| mark_ref_loaded (ref, loop); |
| } |
| init_lim_data (stmt)->ref = ref->id; |
| return; |
| } |
| |
| static unsigned *bb_loop_postorder; |
| |
| /* qsort sort function to sort blocks after their loop fathers postorder. */ |
| |
| static int |
| sort_bbs_in_loop_postorder_cmp (const void *bb1_, const void *bb2_, |
| void *bb_loop_postorder_) |
| { |
| unsigned *bb_loop_postorder = (unsigned *)bb_loop_postorder_; |
| basic_block bb1 = *(const basic_block *)bb1_; |
| basic_block bb2 = *(const basic_block *)bb2_; |
| class loop *loop1 = bb1->loop_father; |
| class loop *loop2 = bb2->loop_father; |
| if (loop1->num == loop2->num) |
| return bb1->index - bb2->index; |
| return bb_loop_postorder[loop1->num] < bb_loop_postorder[loop2->num] ? -1 : 1; |
| } |
| |
| /* qsort sort function to sort ref locs after their loop fathers postorder. */ |
| |
| static int |
| sort_locs_in_loop_postorder_cmp (const void *loc1_, const void *loc2_, |
| void *bb_loop_postorder_) |
| { |
| unsigned *bb_loop_postorder = (unsigned *)bb_loop_postorder_; |
| const mem_ref_loc *loc1 = (const mem_ref_loc *)loc1_; |
| const mem_ref_loc *loc2 = (const mem_ref_loc *)loc2_; |
| class loop *loop1 = gimple_bb (loc1->stmt)->loop_father; |
| class loop *loop2 = gimple_bb (loc2->stmt)->loop_father; |
| if (loop1->num == loop2->num) |
| return 0; |
| return bb_loop_postorder[loop1->num] < bb_loop_postorder[loop2->num] ? -1 : 1; |
| } |
| |
| /* Gathers memory references in loops. */ |
| |
| static void |
| analyze_memory_references (bool store_motion) |
| { |
| gimple_stmt_iterator bsi; |
| basic_block bb, *bbs; |
| class loop *outer; |
| unsigned i, n; |
| |
| /* Collect all basic-blocks in loops and sort them after their |
| loops postorder. */ |
| i = 0; |
| bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS); |
| FOR_EACH_BB_FN (bb, cfun) |
| if (bb->loop_father != current_loops->tree_root) |
| bbs[i++] = bb; |
| n = i; |
| gcc_sort_r (bbs, n, sizeof (basic_block), sort_bbs_in_loop_postorder_cmp, |
| bb_loop_postorder); |
| |
| /* Visit blocks in loop postorder and assign mem-ref IDs in that order. |
| That results in better locality for all the bitmaps. It also |
| automatically sorts the location list of gathered memory references |
| after their loop postorder number allowing to binary-search it. */ |
| for (i = 0; i < n; ++i) |
| { |
| basic_block bb = bbs[i]; |
| for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
| gather_mem_refs_stmt (bb->loop_father, gsi_stmt (bsi)); |
| } |
| |
| /* Verify the list of gathered memory references is sorted after their |
| loop postorder number. */ |
| if (flag_checking) |
| { |
| im_mem_ref *ref; |
| FOR_EACH_VEC_ELT (memory_accesses.refs_list, i, ref) |
| for (unsigned j = 1; j < ref->accesses_in_loop.length (); ++j) |
| gcc_assert (sort_locs_in_loop_postorder_cmp |
| (&ref->accesses_in_loop[j-1], &ref->accesses_in_loop[j], |
| bb_loop_postorder) <= 0); |
| } |
| |
| free (bbs); |
| |
| if (!store_motion) |
| return; |
| |
| /* Propagate the information about accessed memory references up |
| the loop hierarchy. */ |
| for (auto loop : loops_list (cfun, LI_FROM_INNERMOST)) |
| { |
| /* Finalize the overall touched references (including subloops). */ |
| bitmap_ior_into (&memory_accesses.all_refs_stored_in_loop[loop->num], |
| &memory_accesses.refs_stored_in_loop[loop->num]); |
| |
| /* Propagate the information about accessed memory references up |
| the loop hierarchy. */ |
| outer = loop_outer (loop); |
| if (outer == current_loops->tree_root) |
| continue; |
| |
| bitmap_ior_into (&memory_accesses.all_refs_stored_in_loop[outer->num], |
| &memory_accesses.all_refs_stored_in_loop[loop->num]); |
| } |
| } |
| |
| /* Returns true if MEM1 and MEM2 may alias. TTAE_CACHE is used as a cache in |
| tree_to_aff_combination_expand. */ |
| |
| static bool |
| mem_refs_may_alias_p (im_mem_ref *mem1, im_mem_ref *mem2, |
| hash_map<tree, name_expansion *> **ttae_cache, |
| bool tbaa_p) |
| { |
| gcc_checking_assert (mem1->mem.ref != error_mark_node |
| && mem2->mem.ref != error_mark_node); |
| |
| /* Perform BASE + OFFSET analysis -- if MEM1 and MEM2 are based on the same |
| object and their offset differ in such a way that the locations cannot |
| overlap, then they cannot alias. */ |
| poly_widest_int size1, size2; |
| aff_tree off1, off2; |
| |
| /* Perform basic offset and type-based disambiguation. */ |
| if (!refs_may_alias_p_1 (&mem1->mem, &mem2->mem, tbaa_p)) |
| return false; |
| |
| /* The expansion of addresses may be a bit expensive, thus we only do |
| the check at -O2 and higher optimization levels. */ |
| if (optimize < 2) |
| return true; |
| |
| get_inner_reference_aff (mem1->mem.ref, &off1, &size1); |
| get_inner_reference_aff (mem2->mem.ref, &off2, &size2); |
| aff_combination_expand (&off1, ttae_cache); |
| aff_combination_expand (&off2, ttae_cache); |
| aff_combination_scale (&off1, -1); |
| aff_combination_add (&off2, &off1); |
| |
| if (aff_comb_cannot_overlap_p (&off2, size1, size2)) |
| return false; |
| |
| return true; |
| } |
| |
| /* Compare function for bsearch searching for reference locations |
| in a loop. */ |
| |
| static int |
| find_ref_loc_in_loop_cmp (const void *loop_, const void *loc_, |
| void *bb_loop_postorder_) |
| { |
| unsigned *bb_loop_postorder = (unsigned *)bb_loop_postorder_; |
| class loop *loop = (class loop *)const_cast<void *>(loop_); |
| mem_ref_loc *loc = (mem_ref_loc *)const_cast<void *>(loc_); |
| class loop *loc_loop = gimple_bb (loc->stmt)->loop_father; |
| if (loop->num == loc_loop->num |
| || flow_loop_nested_p (loop, loc_loop)) |
| return 0; |
| return (bb_loop_postorder[loop->num] < bb_loop_postorder[loc_loop->num] |
| ? -1 : 1); |
| } |
| |
| /* Iterates over all locations of REF in LOOP and its subloops calling |
| fn.operator() with the location as argument. When that operator |
| returns true the iteration is stopped and true is returned. |
| Otherwise false is returned. */ |
| |
| template <typename FN> |
| static bool |
| for_all_locs_in_loop (class loop *loop, im_mem_ref *ref, FN fn) |
| { |
| unsigned i; |
| mem_ref_loc *loc; |
| |
| /* Search for the cluster of locs in the accesses_in_loop vector |
| which is sorted after postorder index of the loop father. */ |
| loc = ref->accesses_in_loop.bsearch (loop, find_ref_loc_in_loop_cmp, |
| bb_loop_postorder); |
| if (!loc) |
| return false; |
| |
| /* We have found one location inside loop or its sub-loops. Iterate |
| both forward and backward to cover the whole cluster. */ |
| i = loc - ref->accesses_in_loop.address (); |
| while (i > 0) |
| { |
| --i; |
| mem_ref_loc *l = &ref->accesses_in_loop[i]; |
| if (!flow_bb_inside_loop_p (loop, gimple_bb (l->stmt))) |
| break; |
| if (fn (l)) |
| return true; |
| } |
| for (i = loc - ref->accesses_in_loop.address (); |
| i < ref->accesses_in_loop.length (); ++i) |
| { |
| mem_ref_loc *l = &ref->accesses_in_loop[i]; |
| if (!flow_bb_inside_loop_p (loop, gimple_bb (l->stmt))) |
| break; |
| if (fn (l)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* Rewrites location LOC by TMP_VAR. */ |
| |
| class rewrite_mem_ref_loc |
| { |
| public: |
| rewrite_mem_ref_loc (tree tmp_var_) : tmp_var (tmp_var_) {} |
| bool operator () (mem_ref_loc *loc); |
| tree tmp_var; |
| }; |
| |
| bool |
| rewrite_mem_ref_loc::operator () (mem_ref_loc *loc) |
| { |
| *loc->ref = tmp_var; |
| update_stmt (loc->stmt); |
| return false; |
| } |
| |
| /* Rewrites all references to REF in LOOP by variable TMP_VAR. */ |
| |
| static void |
| rewrite_mem_refs (class loop *loop, im_mem_ref *ref, tree tmp_var) |
| { |
| for_all_locs_in_loop (loop, ref, rewrite_mem_ref_loc (tmp_var)); |
| } |
| |
| /* Stores the first reference location in LOCP. */ |
| |
| class first_mem_ref_loc_1 |
| { |
| public: |
| first_mem_ref_loc_1 (mem_ref_loc **locp_) : locp (locp_) {} |
| bool operator () (mem_ref_loc *loc); |
| mem_ref_loc **locp; |
| }; |
| |
| bool |
| first_mem_ref_loc_1::operator () (mem_ref_loc *loc) |
| { |
| *locp = loc; |
| return true; |
| } |
| |
| /* Returns the first reference location to REF in LOOP. */ |
| |
| static mem_ref_loc * |
| first_mem_ref_loc (class loop *loop, im_mem_ref *ref) |
| { |
| mem_ref_loc *locp = NULL; |
| for_all_locs_in_loop (loop, ref, first_mem_ref_loc_1 (&locp)); |
| return locp; |
| } |
| |
| /* Helper function for execute_sm. Emit code to store TMP_VAR into |
| MEM along edge EX. |
| |
| The store is only done if MEM has changed. We do this so no |
| changes to MEM occur on code paths that did not originally store |
| into it. |
| |
| The common case for execute_sm will transform: |
| |
| for (...) { |
| if (foo) |
| stuff; |
| else |
| MEM = TMP_VAR; |
| } |
| |
| into: |
| |
| lsm = MEM; |
| for (...) { |
| if (foo) |
| stuff; |
| else |
| lsm = TMP_VAR; |
| } |
| MEM = lsm; |
| |
| This function will generate: |
| |
| lsm = MEM; |
| |
| lsm_flag = false; |
| ... |
| for (...) { |
| if (foo) |
| stuff; |
| else { |
| lsm = TMP_VAR; |
| lsm_flag = true; |
| } |
| } |
| if (lsm_flag) <-- |
| MEM = lsm; <-- (X) |
| |
| In case MEM and TMP_VAR are NULL the function will return the then |
| block so the caller can insert (X) and other related stmts. |
| */ |
| |
| static basic_block |
| execute_sm_if_changed (edge ex, tree mem, tree tmp_var, tree flag, |
| edge preheader, hash_set <basic_block> *flag_bbs, |
| edge &append_cond_position, edge &last_cond_fallthru) |
| { |
| basic_block new_bb, then_bb, old_dest; |
| bool loop_has_only_one_exit; |
| edge then_old_edge; |
| gimple_stmt_iterator gsi; |
| gimple *stmt; |
| bool irr = ex->flags & EDGE_IRREDUCIBLE_LOOP; |
| |
| profile_count count_sum = profile_count::zero (); |
| int nbbs = 0, ncount = 0; |
| profile_probability flag_probability = profile_probability::uninitialized (); |
| |
| /* Flag is set in FLAG_BBS. Determine probability that flag will be true |
| at loop exit. |
| |
| This code may look fancy, but it cannot update profile very realistically |
| because we do not know the probability that flag will be true at given |
| loop exit. |
| |
| We look for two interesting extremes |
| - when exit is dominated by block setting the flag, we know it will |
| always be true. This is a common case. |
| - when all blocks setting the flag have very low frequency we know |
| it will likely be false. |
| In all other cases we default to 2/3 for flag being true. */ |
| |
| for (hash_set<basic_block>::iterator it = flag_bbs->begin (); |
| it != flag_bbs->end (); ++it) |
| { |
| if ((*it)->count.initialized_p ()) |
| count_sum += (*it)->count, ncount ++; |
| if (dominated_by_p (CDI_DOMINATORS, ex->src, *it)) |
| flag_probability = profile_probability::always (); |
| nbbs++; |
| } |
| |
| profile_probability cap = profile_probability::always ().apply_scale (2, 3); |
| |
| if (flag_probability.initialized_p ()) |
| ; |
| else if (ncount == nbbs |
| && preheader->count () >= count_sum && preheader->count ().nonzero_p ()) |
| { |
| flag_probability = count_sum.probability_in (preheader->count ()); |
| if (flag_probability > cap) |
| flag_probability = cap; |
| } |
| |
| if (!flag_probability.initialized_p ()) |
| flag_probability = cap; |
| |
| /* ?? Insert store after previous store if applicable. See note |
| below. */ |
| if (append_cond_position) |
| ex = append_cond_position; |
| |
| loop_has_only_one_exit = single_pred_p (ex->dest); |
| |
| if (loop_has_only_one_exit) |
| ex = split_block_after_labels (ex->dest); |
| else |
| { |
| for (gphi_iterator gpi = gsi_start_phis (ex->dest); |
| !gsi_end_p (gpi); gsi_next (&gpi)) |
| { |
| gphi *phi = gpi.phi (); |
| if (virtual_operand_p (gimple_phi_result (phi))) |
| continue; |
| |
| /* When the destination has a non-virtual PHI node with multiple |
| predecessors make sure we preserve the PHI structure by |
| forcing a forwarder block so that hoisting of that PHI will |
| still work. */ |
| split_edge (ex); |
| break; |
| } |
| } |
| |
| old_dest = ex->dest; |
| new_bb = split_edge (ex); |
| then_bb = create_empty_bb (new_bb); |
| then_bb->count = new_bb->count.apply_probability (flag_probability); |
| if (irr) |
| then_bb->flags = BB_IRREDUCIBLE_LOOP; |
| add_bb_to_loop (then_bb, new_bb->loop_father); |
| |
| gsi = gsi_start_bb (new_bb); |
| stmt = gimple_build_cond (NE_EXPR, flag, boolean_false_node, |
| NULL_TREE, NULL_TREE); |
| gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING); |
| |
| /* Insert actual store. */ |
| if (mem) |
| { |
| gsi = gsi_start_bb (then_bb); |
| stmt = gimple_build_assign (unshare_expr (mem), tmp_var); |
| gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING); |
| } |
| |
| edge e1 = single_succ_edge (new_bb); |
| edge e2 = make_edge (new_bb, then_bb, |
| EDGE_TRUE_VALUE | (irr ? EDGE_IRREDUCIBLE_LOOP : 0)); |
| e2->probability = flag_probability; |
| |
| e1->flags |= EDGE_FALSE_VALUE | (irr ? EDGE_IRREDUCIBLE_LOOP : 0); |
| e1->flags &= ~EDGE_FALLTHRU; |
| |
| e1->probability = flag_probability.invert (); |
| |
| then_old_edge = make_single_succ_edge (then_bb, old_dest, |
| EDGE_FALLTHRU | (irr ? EDGE_IRREDUCIBLE_LOOP : 0)); |
| |
| set_immediate_dominator (CDI_DOMINATORS, then_bb, new_bb); |
| |
| if (append_cond_position) |
| { |
| basic_block prevbb = last_cond_fallthru->src; |
| redirect_edge_succ (last_cond_fallthru, new_bb); |
| set_immediate_dominator (CDI_DOMINATORS, new_bb, prevbb); |
| set_immediate_dominator (CDI_DOMINATORS, old_dest, |
| recompute_dominator (CDI_DOMINATORS, old_dest)); |
| } |
| |
| /* ?? Because stores may alias, they must happen in the exact |
| sequence they originally happened. Save the position right after |
| the (_lsm) store we just created so we can continue appending after |
| it and maintain the original order. */ |
| append_cond_position = then_old_edge; |
| last_cond_fallthru = find_edge (new_bb, old_dest); |
| |
| if (!loop_has_only_one_exit) |
| for (gphi_iterator gpi = gsi_start_phis (old_dest); |
| !gsi_end_p (gpi); gsi_next (&gpi)) |
| { |
| gphi *phi = gpi.phi (); |
| unsigned i; |
| |
| for (i = 0; i < gimple_phi_num_args (phi); i++) |
| if (gimple_phi_arg_edge (phi, i)->src == new_bb) |
| { |
| tree arg = gimple_phi_arg_def (phi, i); |
| add_phi_arg (phi, arg, then_old_edge, UNKNOWN_LOCATION); |
| update_stmt (phi); |
| } |
| } |
| |
| return then_bb; |
| } |
| |
| /* When REF is set on the location, set flag indicating the store. */ |
| |
| class sm_set_flag_if_changed |
| { |
| public: |
| sm_set_flag_if_changed (tree flag_, hash_set <basic_block> *bbs_) |
| : flag (flag_), bbs (bbs_) {} |
| bool operator () (mem_ref_loc *loc); |
| tree flag; |
| hash_set <basic_block> *bbs; |
| }; |
| |
| bool |
| sm_set_flag_if_changed::operator () (mem_ref_loc *loc) |
| { |
| /* Only set the flag for writes. */ |
| if (is_gimple_assign (loc->stmt) |
| && gimple_assign_lhs_ptr (loc->stmt) == loc->ref) |
| { |
| gimple_stmt_iterator gsi = gsi_for_stmt (loc->stmt); |
| gimple *stmt = gimple_build_assign (flag, boolean_true_node); |
| gsi_insert_after (&gsi, stmt, GSI_CONTINUE_LINKING); |
| bbs->add (gimple_bb (stmt)); |
| } |
| return false; |
| } |
| |
| /* Helper function for execute_sm. On every location where REF is |
| set, set an appropriate flag indicating the store. */ |
| |
| static tree |
| execute_sm_if_changed_flag_set (class loop *loop, im_mem_ref *ref, |
| hash_set <basic_block> *bbs) |
| { |
| tree flag; |
| char *str = get_lsm_tmp_name (ref->mem.ref, ~0, "_flag"); |
| flag = create_tmp_reg (boolean_type_node, str); |
| for_all_locs_in_loop (loop, ref, sm_set_flag_if_changed (flag, bbs)); |
| return flag; |
| } |
| |
| struct sm_aux |
| { |
| tree tmp_var; |
| tree store_flag; |
| hash_set <basic_block> flag_bbs; |
| }; |
| |
| /* Executes store motion of memory reference REF from LOOP. |
| Exits from the LOOP are stored in EXITS. The initialization of the |
| temporary variable is put to the preheader of the loop, and assignments |
| to the reference from the temporary variable are emitted to exits. */ |
| |
| static void |
| execute_sm (class loop *loop, im_mem_ref *ref, |
| hash_map<im_mem_ref *, sm_aux *> &aux_map, bool maybe_mt, |
| bool use_other_flag_var) |
| { |
| gassign *load; |
| struct fmt_data fmt_data; |
| struct lim_aux_data *lim_data; |
| bool multi_threaded_model_p = false; |
| gimple_stmt_iterator gsi; |
| sm_aux *aux = new sm_aux; |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Executing store motion of "); |
| print_generic_expr (dump_file, ref->mem.ref); |
| fprintf (dump_file, " from loop %d\n", loop->num); |
| } |
| |
| aux->tmp_var = create_tmp_reg (TREE_TYPE (ref->mem.ref), |
| get_lsm_tmp_name (ref->mem.ref, ~0)); |
| |
| fmt_data.loop = loop; |
| fmt_data.orig_loop = loop; |
| for_each_index (&ref->mem.ref, force_move_till, &fmt_data); |
| |
| bool always_stored = ref_always_accessed_p (loop, ref, true); |
| if (maybe_mt |
| && (bb_in_transaction (loop_preheader_edge (loop)->src) |
| || (! flag_store_data_races && ! always_stored))) |
| multi_threaded_model_p = true; |
| |
| if (multi_threaded_model_p && !use_other_flag_var) |
| aux->store_flag |
| = execute_sm_if_changed_flag_set (loop, ref, &aux->flag_bbs); |
| else |
| aux->store_flag = NULL_TREE; |
| |
| /* Remember variable setup. */ |
| aux_map.put (ref, aux); |
| |
| rewrite_mem_refs (loop, ref, aux->tmp_var); |
| |
| /* Emit the load code on a random exit edge or into the latch if |
| the loop does not exit, so that we are sure it will be processed |
| by move_computations after all dependencies. */ |
| gsi = gsi_for_stmt (first_mem_ref_loc (loop, ref)->stmt); |
| |
| /* Avoid doing a load if there was no load of the ref in the loop. |
| Esp. when the ref is not always stored we cannot optimize it |
| away later. But when it is not always stored we must use a conditional |
| store then. */ |
| if ((!always_stored && !multi_threaded_model_p) |
| || (ref->loaded && bitmap_bit_p (ref->loaded, loop->num))) |
| load = gimple_build_assign (aux->tmp_var, unshare_expr (ref->mem.ref)); |
| else |
| { |
| /* If not emitting a load mark the uninitialized state on the |
| loop entry as not to be warned for. */ |
| tree uninit = create_tmp_reg (TREE_TYPE (aux->tmp_var)); |
| suppress_warning (uninit, OPT_Wuninitialized); |
| load = gimple_build_assign (aux->tmp_var, uninit); |
| } |
| lim_data = init_lim_data (load); |
| lim_data->max_loop = loop; |
| lim_data->tgt_loop = loop; |
| gsi_insert_before (&gsi, load, GSI_SAME_STMT); |
| |
| if (aux->store_flag) |
| { |
| load = gimple_build_assign (aux->store_flag, boolean_false_node); |
| lim_data = init_lim_data (load); |
| lim_data->max_loop = loop; |
| lim_data->tgt_loop = loop; |
| gsi_insert_before (&gsi, load, GSI_SAME_STMT); |
| } |
| } |
| |
| /* sm_ord is used for ordinary stores we can retain order with respect |
| to other stores |
| sm_unord is used for conditional executed stores which need to be |
| able to execute in arbitrary order with respect to other stores |
| sm_other is used for stores we do not try to apply store motion to. */ |
| enum sm_kind { sm_ord, sm_unord, sm_other }; |
| struct seq_entry |
| { |
| seq_entry () {} |
| seq_entry (unsigned f, sm_kind k, tree fr = NULL) |
| : first (f), second (k), from (fr) {} |
| unsigned first; |
| sm_kind second; |
| tree from; |
| }; |
| |
| static void |
| execute_sm_exit (class loop *loop, edge ex, vec<seq_entry> &seq, |
| hash_map<im_mem_ref *, sm_aux *> &aux_map, sm_kind kind, |
| edge &append_cond_position, edge &last_cond_fallthru) |
| { |
| /* Sink the stores to exit from the loop. */ |
| for (unsigned i = seq.length (); i > 0; --i) |
| { |
| im_mem_ref *ref = memory_accesses.refs_list[seq[i-1].first]; |
| if (seq[i-1].second == sm_other) |
| { |
| gcc_assert (kind == sm_ord && seq[i-1].from != NULL_TREE); |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Re-issueing dependent store of "); |
| print_generic_expr (dump_file, ref->mem.ref); |
| fprintf (dump_file, " from loop %d on exit %d -> %d\n", |
| loop->num, ex->src->index, ex->dest->index); |
| } |
| gassign *store = gimple_build_assign (unshare_expr (ref->mem.ref), |
| seq[i-1].from); |
| gsi_insert_on_edge (ex, store); |
| } |
| else |
| { |
| sm_aux *aux = *aux_map.get (ref); |
| if (!aux->store_flag || kind == sm_ord) |
| { |
| gassign *store; |
| store = gimple_build_assign (unshare_expr (ref->mem.ref), |
| aux->tmp_var); |
| gsi_insert_on_edge (ex, store); |
| } |
| else |
| execute_sm_if_changed (ex, ref->mem.ref, aux->tmp_var, |
| aux->store_flag, |
| loop_preheader_edge (loop), &aux->flag_bbs, |
| append_cond_position, last_cond_fallthru); |
| } |
| } |
| } |
| |
| /* Push the SM candidate at index PTR in the sequence SEQ down until |
| we hit the next SM candidate. Return true if that went OK and |
| false if we could not disambiguate agains another unrelated ref. |
| Update *AT to the index where the candidate now resides. */ |
| |
| static bool |
| sm_seq_push_down (vec<seq_entry> &seq, unsigned ptr, unsigned *at) |
| { |
| *at = ptr; |
| for (; ptr > 0; --ptr) |
| { |
| seq_entry &new_cand = seq[ptr]; |
| seq_entry &against = seq[ptr-1]; |
| if (against.second == sm_ord |
| || (against.second == sm_other && against.from != NULL_TREE)) |
| /* Found the tail of the sequence. */ |
| break; |
| /* We may not ignore self-dependences here. */ |
| if (new_cand.first == against.first |
| || !refs_independent_p (memory_accesses.refs_list[new_cand.first], |
| memory_accesses.refs_list[against.first], |
| false)) |
| /* ??? Prune new_cand from the list of refs to apply SM to. */ |
| return false; |
| std::swap (new_cand, against); |
| *at = ptr - 1; |
| } |
| return true; |
| } |
| |
| /* Computes the sequence of stores from candidates in REFS_NOT_IN_SEQ to SEQ |
| walking backwards from VDEF (or the end of BB if VDEF is NULL). */ |
| |
| static int |
| sm_seq_valid_bb (class loop *loop, basic_block bb, tree vdef, |
| vec<seq_entry> &seq, bitmap refs_not_in_seq, |
| bitmap refs_not_supported, bool forked, |
| bitmap fully_visited) |
| { |
| if (!vdef) |
| for (gimple_stmt_iterator gsi = gsi_last_bb (bb); !gsi_end_p (gsi); |
| gsi_prev (&gsi)) |
| { |
| vdef = gimple_vdef (gsi_stmt (gsi)); |
| if (vdef) |
| break; |
| } |
| if (!vdef) |
| { |
| gphi *vphi = get_virtual_phi (bb); |
| if (vphi) |
| vdef = gimple_phi_result (vphi); |
| } |
| if (!vdef) |
| { |
| if (single_pred_p (bb)) |
| /* This handles the perfect nest case. */ |
| return sm_seq_valid_bb (loop, single_pred (bb), vdef, |
| seq, refs_not_in_seq, refs_not_supported, |
| forked, fully_visited); |
| return 0; |
| } |
| do |
| { |
| gimple *def = SSA_NAME_DEF_STMT (vdef); |
| if (gimple_bb (def) != bb) |
| { |
| /* If we forked by processing a PHI do not allow our walk to |
| merge again until we handle that robustly. */ |
| if (forked) |
| { |
| /* Mark refs_not_in_seq as unsupported. */ |
| bitmap_ior_into (refs_not_supported, refs_not_in_seq); |
| return 1; |
| } |
| /* Otherwise it doesn't really matter if we end up in different |
| BBs. */ |
| bb = gimple_bb (def); |
| } |
| if (gphi *phi = dyn_cast <gphi *> (def)) |
| { |
| /* Handle CFG merges. Until we handle forks (gimple_bb (def) != bb) |
| this is still linear. |
| Eventually we want to cache intermediate results per BB |
| (but we can't easily cache for different exits?). */ |
| /* Stop at PHIs with possible backedges. */ |
| if (bb == bb->loop_father->header |
| || bb->flags & BB_IRREDUCIBLE_LOOP) |
| { |
| /* Mark refs_not_in_seq as unsupported. */ |
| bitmap_ior_into (refs_not_supported, refs_not_in_seq); |
| return 1; |
| } |
| if (gimple_phi_num_args (phi) == 1) |
| return sm_seq_valid_bb (loop, gimple_phi_arg_edge (phi, 0)->src, |
| gimple_phi_arg_def (phi, 0), seq, |
| refs_not_in_seq, refs_not_supported, |
| false, fully_visited); |
| if (bitmap_bit_p (fully_visited, |
| SSA_NAME_VERSION (gimple_phi_result (phi)))) |
| return 1; |
| auto_vec<seq_entry> first_edge_seq; |
| auto_bitmap tem_refs_not_in_seq (&lim_bitmap_obstack); |
| int eret; |
| bitmap_copy (tem_refs_not_in_seq, refs_not_in_seq); |
| eret = sm_seq_valid_bb (loop, gimple_phi_arg_edge (phi, 0)->src, |
| gimple_phi_arg_def (phi, 0), |
| first_edge_seq, |
| tem_refs_not_in_seq, refs_not_supported, |
| true, fully_visited); |
| if (eret != 1) |
| return -1; |
| /* Simplify our lives by pruning the sequence of !sm_ord. */ |
| while (!first_edge_seq.is_empty () |
| && first_edge_seq.last ().second != sm_ord) |
| first_edge_seq.pop (); |
| for (unsigned int i = 1; i < gimple_phi_num_args (phi); ++i) |
| { |
| tree vuse = gimple_phi_arg_def (phi, i); |
| edge e = gimple_phi_arg_edge (phi, i); |
| auto_vec<seq_entry> edge_seq; |
| bitmap_and_compl (tem_refs_not_in_seq, |
| refs_not_in_seq, refs_not_supported); |
| /* If we've marked all refs we search for as unsupported |
| we can stop processing and use the sequence as before |
| the PHI. */ |
| if (bitmap_empty_p (tem_refs_not_in_seq)) |
| return 1; |
| eret = sm_seq_valid_bb (loop, e->src, vuse, edge_seq, |
| tem_refs_not_in_seq, refs_not_supported, |
| true, fully_visited); |
| if (eret != 1) |
| return -1; |
| /* Simplify our lives by pruning the sequence of !sm_ord. */ |
| while (!edge_seq.is_empty () |
| && edge_seq.last ().second != sm_ord) |
| edge_seq.pop (); |
| unsigned min_len = MIN(first_edge_seq.length (), |
| edge_seq.length ()); |
| /* Incrementally merge seqs into first_edge_seq. */ |
| int first_uneq = -1; |
| auto_vec<seq_entry, 2> extra_refs; |
| for (unsigned int i = 0; i < min_len; ++i) |
| { |
| /* ??? We can more intelligently merge when we face different |
| order by additional sinking operations in one sequence. |
| For now we simply mark them as to be processed by the |
| not order-preserving SM code. */ |
| if (first_edge_seq[i].first != edge_seq[i].first) |
| { |
| if (first_edge_seq[i].second == sm_ord) |
| bitmap_set_bit (refs_not_supported, |
| first_edge_seq[i].first); |
| if (edge_seq[i].second == sm_ord) |
| bitmap_set_bit (refs_not_supported, edge_seq[i].first); |
| first_edge_seq[i].second = sm_other; |
| first_edge_seq[i].from = NULL_TREE; |
| /* Record the dropped refs for later processing. */ |
| if (first_uneq == -1) |
| first_uneq = i; |
| extra_refs.safe_push (seq_entry (edge_seq[i].first, |
| sm_other, NULL_TREE)); |
| } |
| /* sm_other prevails. */ |
| else if (first_edge_seq[i].second != edge_seq[i].second) |
| { |
| /* Make sure the ref is marked as not supported. */ |
| bitmap_set_bit (refs_not_supported, |
| first_edge_seq[i].first); |
| first_edge_seq[i].second = sm_other; |
| first_edge_seq[i].from = NULL_TREE; |
| } |
| else if (first_edge_seq[i].second == sm_other |
| && first_edge_seq[i].from != NULL_TREE |
| && (edge_seq[i].from == NULL_TREE |
| || !operand_equal_p (first_edge_seq[i].from, |
| edge_seq[i].from, 0))) |
| first_edge_seq[i].from = NULL_TREE; |
| } |
| /* Any excess elements become sm_other since they are now |
| coonditionally executed. */ |
| if (first_edge_seq.length () > edge_seq.length ()) |
| { |
| for (unsigned i = edge_seq.length (); |
| i < first_edge_seq.length (); ++i) |
| { |
| if (first_edge_seq[i].second == sm_ord) |
| bitmap_set_bit (refs_not_supported, |
| first_edge_seq[i].first); |
| first_edge_seq[i].second = sm_other; |
| } |
| } |
| else if (edge_seq.length () > first_edge_seq.length ()) |
| { |
| if (first_uneq == -1) |
| first_uneq = first_edge_seq.length (); |
| for (unsigned i = first_edge_seq.length (); |
| i < edge_seq.length (); ++i) |
| { |
| if (edge_seq[i].second == sm_ord) |
| bitmap_set_bit (refs_not_supported, edge_seq[i].first); |
| extra_refs.safe_push (seq_entry (edge_seq[i].first, |
| sm_other, NULL_TREE)); |
| } |
| } |
| /* Put unmerged refs at first_uneq to force dependence checking |
| on them. */ |
| if (first_uneq != -1) |
| { |
| /* Missing ordered_splice_at. */ |
| if ((unsigned)first_uneq == first_edge_seq.length ()) |
| first_edge_seq.safe_splice (extra_refs); |
| else |
| { |
| unsigned fes_length = first_edge_seq.length (); |
| first_edge_seq.safe_grow (fes_length |
| + extra_refs.length ()); |
| memmove (&first_edge_seq[first_uneq + extra_refs.length ()], |
| &first_edge_seq[first_uneq], |
| (fes_length - first_uneq) * sizeof (seq_entry)); |
| memcpy (&first_edge_seq[first_uneq], |
| extra_refs.address (), |
| extra_refs.length () * sizeof (seq_entry)); |
| } |
| } |
| } |
| /* Use the sequence from the first edge and push SMs down. */ |
| for (unsigned i = 0; i < first_edge_seq.length (); ++i) |
| { |
| unsigned id = first_edge_seq[i].first; |
| seq.safe_push (first_edge_seq[i]); |
| unsigned new_idx; |
| if ((first_edge_seq[i].second == sm_ord |
| || (first_edge_seq[i].second == sm_other |
| && first_edge_seq[i].from != NULL_TREE)) |
| && !sm_seq_push_down (seq, seq.length () - 1, &new_idx)) |
| { |
| if (first_edge_seq[i].second == sm_ord) |
| bitmap_set_bit (refs_not_supported, id); |
| /* Mark it sm_other. */ |
| seq[new_idx].second = sm_other; |
| seq[new_idx].from = NULL_TREE; |
| } |
| } |
| bitmap_set_bit (fully_visited, |
| SSA_NAME_VERSION (gimple_phi_result (phi))); |
| return 1; |
| } |
| lim_aux_data *data = get_lim_data (def); |
| gcc_assert (data); |
| if (data->ref == UNANALYZABLE_MEM_ID) |
| return -1; |
| /* Stop at memory references which we can't move. */ |
| else if (memory_accesses.refs_list[data->ref]->mem.ref == error_mark_node) |
| { |
| /* Mark refs_not_in_seq as unsupported. */ |
| bitmap_ior_into (refs_not_supported, refs_not_in_seq); |
| return 1; |
| } |
| /* One of the stores we want to apply SM to and we've not yet seen. */ |
| else if (bitmap_clear_bit (refs_not_in_seq, data->ref)) |
| { |
| seq.safe_push (seq_entry (data->ref, sm_ord)); |
| |
| /* 1) push it down the queue until a SMed |
| and not ignored ref is reached, skipping all not SMed refs |
| and ignored refs via non-TBAA disambiguation. */ |
| unsigned new_idx; |
| if (!sm_seq_push_down (seq, seq.length () - 1, &new_idx) |
| /* If that fails but we did not fork yet continue, we'll see |
| to re-materialize all of the stores in the sequence then. |
| Further stores will only be pushed up to this one. */ |
| && forked) |
| { |
| bitmap_set_bit (refs_not_supported, data->ref); |
| /* Mark it sm_other. */ |
| seq[new_idx].second = sm_other; |
| } |
| |
| /* 2) check whether we've seen all refs we want to SM and if so |
| declare success for the active exit */ |
| if (bitmap_empty_p (refs_not_in_seq)) |
| return 1; |
| } |
| else |
| /* Another store not part of the final sequence. Simply push it. */ |
| seq.safe_push (seq_entry (data->ref, sm_other, |
| gimple_assign_rhs1 (def))); |
| |
| vdef = gimple_vuse (def); |
| } |
| while (1); |
| } |
| |
| /* Hoists memory references MEM_REFS out of LOOP. EXITS is the list of exit |
| edges of the LOOP. */ |
| |
| static void |
| hoist_memory_references (class loop *loop, bitmap mem_refs, |
| const vec<edge> &exits) |
| { |
| im_mem_ref *ref; |
| unsigned i; |
| bitmap_iterator bi; |
| |
| /* There's a special case we can use ordered re-materialization for |
| conditionally excuted stores which is when all stores in the loop |
| happen in the same basic-block. In that case we know we'll reach |
| all stores and thus can simply process that BB and emit a single |
| conditional block of ordered materializations. See PR102436. */ |
| basic_block single_store_bb = NULL; |
| EXECUTE_IF_SET_IN_BITMAP (&memory_accesses.all_refs_stored_in_loop[loop->num], |
| 0, i, bi) |
| { |
| bool fail = false; |
| ref = memory_accesses.refs_list[i]; |
| for (auto loc : ref->accesses_in_loop) |
| if (!gimple_vdef (loc.stmt)) |
| ; |
| else if (!single_store_bb) |
| { |
| single_store_bb = gimple_bb (loc.stmt); |
| bool conditional = false; |
| for (edge e : exits) |
| if (!dominated_by_p (CDI_DOMINATORS, e->src, single_store_bb)) |
| { |
| /* Conditional as seen from e. */ |
| conditional = true; |
| break; |
| } |
| if (!conditional) |
| { |
| fail = true; |
| break; |
| } |
| } |
| else if (single_store_bb != gimple_bb (loc.stmt)) |
| { |
| fail = true; |
| break; |
| } |
| if (fail) |
| { |
| single_store_bb = NULL; |
| break; |
| } |
| } |
| if (single_store_bb) |
| { |
| /* Analyze the single block with stores. */ |
| auto_bitmap fully_visited; |
| auto_bitmap refs_not_supported; |
| auto_bitmap refs_not_in_seq; |
| auto_vec<seq_entry> seq; |
| bitmap_copy (refs_not_in_seq, mem_refs); |
| int res = sm_seq_valid_bb (loop, single_store_bb, NULL_TREE, |
| seq, refs_not_in_seq, refs_not_supported, |
| false, fully_visited); |
| if (res != 1) |
| { |
| /* Unhandled refs can still fail this. */ |
| bitmap_clear (mem_refs); |
| return; |
| } |
| |
| /* We cannot handle sm_other since we neither remember the |
| stored location nor the value at the point we execute them. */ |
| for (unsigned i = 0; i < seq.length (); ++i) |
| { |
| unsigned new_i; |
| if (seq[i].second == sm_other |
| && seq[i].from != NULL_TREE) |
| seq[i].from = NULL_TREE; |
| else if ((seq[i].second == sm_ord |
| || (seq[i].second == sm_other |
| && seq[i].from != NULL_TREE)) |
| && !sm_seq_push_down (seq, i, &new_i)) |
| { |
| bitmap_set_bit (refs_not_supported, seq[new_i].first); |
| seq[new_i].second = sm_other; |
| seq[new_i].from = NULL_TREE; |
| } |
| } |
| bitmap_and_compl_into (mem_refs, refs_not_supported); |
| if (bitmap_empty_p (mem_refs)) |
| return; |
| |
| /* Prune seq. */ |
| while (seq.last ().second == sm_other |
| && seq.last ().from == NULL_TREE) |
| seq.pop (); |
| |
| hash_map<im_mem_ref *, sm_aux *> aux_map; |
| |
| /* Execute SM but delay the store materialization for ordered |
| sequences on exit. */ |
| bool first_p = true; |
| EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi) |
| { |
| ref = memory_accesses.refs_list[i]; |
| execute_sm (loop, ref, aux_map, true, !first_p); |
| first_p = false; |
| } |
| |
| /* Get at the single flag variable we eventually produced. */ |
| im_mem_ref *ref |
| = memory_accesses.refs_list[bitmap_first_set_bit (mem_refs)]; |
| sm_aux *aux = *aux_map.get (ref); |
| |
| /* Materialize ordered store sequences on exits. */ |
| edge e; |
| FOR_EACH_VEC_ELT (exits, i, e) |
| { |
| edge append_cond_position = NULL; |
| edge last_cond_fallthru = NULL; |
| edge insert_e = e; |
| /* Construct the single flag variable control flow and insert |
| the ordered seq of stores in the then block. With |
| -fstore-data-races we can do the stores unconditionally. */ |
| if (aux->store_flag) |
| insert_e |
| = single_pred_edge |
| (execute_sm_if_changed (e, NULL_TREE, NULL_TREE, |
| aux->store_flag, |
| loop_preheader_edge (loop), |
| &aux->flag_bbs, append_cond_position, |
| last_cond_fallthru)); |
| execute_sm_exit (loop, insert_e, seq, aux_map, sm_ord, |
| append_cond_position, last_cond_fallthru); |
| gsi_commit_one_edge_insert (insert_e, NULL); |
| } |
| |
| for (hash_map<im_mem_ref *, sm_aux *>::iterator iter = aux_map.begin (); |
| iter != aux_map.end (); ++iter) |
| delete (*iter).second; |
| |
| return; |
| } |
| |
| /* To address PR57359 before actually applying store-motion check |
| the candidates found for validity with regards to reordering |
| relative to other stores which we until here disambiguated using |
| TBAA which isn't valid. |
| What matters is the order of the last stores to the mem_refs |
| with respect to the other stores of the loop at the point of the |
| loop exits. */ |
| |
| /* For each exit compute the store order, pruning from mem_refs |
| on the fly. */ |
| /* The complexity of this is at least |
| O(number of exits * number of SM refs) but more approaching |
| O(number of exits * number of SM refs * number of stores). */ |
| /* ??? Somehow do this in a single sweep over the loop body. */ |
| auto_vec<std::pair<edge, vec<seq_entry> > > sms; |
| auto_bitmap refs_not_supported (&lim_bitmap_obstack); |
| edge e; |
| FOR_EACH_VEC_ELT (exits, i, e) |
| { |
| vec<seq_entry> seq; |
| seq.create (4); |
| auto_bitmap refs_not_in_seq (&lim_bitmap_obstack); |
| bitmap_and_compl (refs_not_in_seq, mem_refs, refs_not_supported); |
| if (bitmap_empty_p (refs_not_in_seq)) |
| { |
| seq.release (); |
| break; |
| } |
| auto_bitmap fully_visited; |
| int res = sm_seq_valid_bb (loop, e->src, NULL_TREE, |
| seq, refs_not_in_seq, |
| refs_not_supported, false, |
| fully_visited); |
| if (res != 1) |
| { |
| bitmap_copy (refs_not_supported, mem_refs); |
| seq.release (); |
| break; |
| } |
| sms.safe_push (std::make_pair (e, seq)); |
| } |
| |
| /* Prune pruned mem_refs from earlier processed exits. */ |
| bool changed = !bitmap_empty_p (refs_not_supported); |
| while (changed) |
| { |
| changed = false; |
| std::pair<edge, vec<seq_entry> > *seq; |
| FOR_EACH_VEC_ELT (sms, i, seq) |
| { |
| bool need_to_push = false; |
| for (unsigned i = 0; i < seq->second.length (); ++i) |
| { |
| sm_kind kind = seq->second[i].second; |
| if (kind == sm_other && seq->second[i].from == NULL_TREE) |
| break; |
| unsigned id = seq->second[i].first; |
| unsigned new_idx; |
| if (kind == sm_ord |
| && bitmap_bit_p (refs_not_supported, id)) |
| { |
| seq->second[i].second = sm_other; |
| gcc_assert (seq->second[i].from == NULL_TREE); |
| need_to_push = true; |
| } |
| else if (need_to_push |
| && !sm_seq_push_down (seq->second, i, &new_idx)) |
| { |
| /* We need to push down both sm_ord and sm_other |
| but for the latter we need to disqualify all |
| following refs. */ |
| if (kind == sm_ord) |
| { |
| if (bitmap_set_bit (refs_not_supported, id)) |
| changed = true; |
| seq->second[new_idx].second = sm_other; |
| } |
| else |
| { |
| for (unsigned j = seq->second.length () - 1; |
| j > new_idx; --j) |
| if (seq->second[j].second == sm_ord |
| && bitmap_set_bit (refs_not_supported, |
| seq->second[j].first)) |
| changed = true; |
| seq->second.truncate (new_idx); |
| break; |
| } |
| } |
| } |
| } |
| } |
| std::pair<edge, vec<seq_entry> > *seq; |
| FOR_EACH_VEC_ELT (sms, i, seq) |
| { |
| /* Prune sm_other from the end. */ |
| while (!seq->second.is_empty () |
| && seq->second.last ().second == sm_other) |
| seq->second.pop (); |
| /* Prune duplicates from the start. */ |
| auto_bitmap seen (&lim_bitmap_obstack); |
| unsigned j, k; |
| for (j = k = 0; j < seq->second.length (); ++j) |
| if (bitmap_set_bit (seen, seq->second[j].first)) |
| { |
| if (k != j) |
| seq->second[k] = seq->second[j]; |
| ++k; |
| } |
| seq->second.truncate (k); |
| /* And verify. */ |
| seq_entry *e; |
| FOR_EACH_VEC_ELT (seq->second, j, e) |
| gcc_assert (e->second == sm_ord |
| || (e->second == sm_other && e->from != NULL_TREE)); |
| } |
| |
| /* Verify dependence for refs we cannot handle with the order preserving |
| code (refs_not_supported) or prune them from mem_refs. */ |
| auto_vec<seq_entry> unord_refs; |
| EXECUTE_IF_SET_IN_BITMAP (refs_not_supported, 0, i, bi) |
| { |
| ref = memory_accesses.refs_list[i]; |
| if (!ref_indep_loop_p (loop, ref, sm_waw)) |
| bitmap_clear_bit (mem_refs, i); |
| /* We've now verified store order for ref with respect to all other |
| stores in the loop does not matter. */ |
| else |
| unord_refs.safe_push (seq_entry (i, sm_unord)); |
| } |
| |
| hash_map<im_mem_ref *, sm_aux *> aux_map; |
| |
| /* Execute SM but delay the store materialization for ordered |
| sequences on exit. */ |
| EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi) |
| { |
| ref = memory_accesses.refs_list[i]; |
| execute_sm (loop, ref, aux_map, bitmap_bit_p (refs_not_supported, i), |
| false); |
| } |
| |
| /* Materialize ordered store sequences on exits. */ |
| FOR_EACH_VEC_ELT (exits, i, e) |
| { |
| edge append_cond_position = NULL; |
| edge last_cond_fallthru = NULL; |
| if (i < sms.length ()) |
| { |
| gcc_assert (sms[i].first == e); |
| execute_sm_exit (loop, e, sms[i].second, aux_map, sm_ord, |
| append_cond_position, last_cond_fallthru); |
| sms[i].second.release (); |
| } |
| if (!unord_refs.is_empty ()) |
| execute_sm_exit (loop, e, unord_refs, aux_map, sm_unord, |
| append_cond_position, last_cond_fallthru); |
| /* Commit edge inserts here to preserve the order of stores |
| when an exit exits multiple loops. */ |
| gsi_commit_one_edge_insert (e, NULL); |
| } |
| |
| for (hash_map<im_mem_ref *, sm_aux *>::iterator iter = aux_map.begin (); |
| iter != aux_map.end (); ++iter) |
| delete (*iter).second; |
| } |
| |
| class ref_always_accessed |
| { |
| public: |
| ref_always_accessed (class loop *loop_, bool stored_p_) |
| : loop (loop_), stored_p (stored_p_) {} |
| bool operator () (mem_ref_loc *loc); |
| class loop *loop; |
| bool stored_p; |
| }; |
| |
| bool |
| ref_always_accessed::operator () (mem_ref_loc *loc) |
| { |
| class loop *must_exec; |
| |
| struct lim_aux_data *lim_data = get_lim_data (loc->stmt); |
| if (!lim_data) |
| return false; |
| |
| /* If we require an always executed store make sure the statement |
| is a store. */ |
| if (stored_p) |
| { |
| tree lhs = gimple_get_lhs (loc->stmt); |
| if (!lhs |
| || !(DECL_P (lhs) || REFERENCE_CLASS_P (lhs))) |
| return false; |
| } |
| |
| must_exec = lim_data->always_executed_in; |
| if (!must_exec) |
| return false; |
| |
| if (must_exec == loop |
| || flow_loop_nested_p (must_exec, loop)) |
| return true; |
| |
| return false; |
| } |
| |
| /* Returns true if REF is always accessed in LOOP. If STORED_P is true |
| make sure REF is always stored to in LOOP. */ |
| |
| static bool |
| ref_always_accessed_p (class loop *loop, im_mem_ref *ref, bool stored_p) |
| { |
| return for_all_locs_in_loop (loop, ref, |
| ref_always_accessed (loop, stored_p)); |
| } |
| |
| /* Returns true if REF1 and REF2 are independent. */ |
| |
| static bool |
| refs_independent_p (im_mem_ref *ref1, im_mem_ref *ref2, bool tbaa_p) |
| { |
| if (ref1 == ref2) |
| return true; |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "Querying dependency of refs %u and %u: ", |
| ref1->id, ref2->id); |
| |
| if (mem_refs_may_alias_p (ref1, ref2, &memory_accesses.ttae_cache, tbaa_p)) |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "dependent.\n"); |
| return false; |
| } |
| else |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "independent.\n"); |
| return true; |
| } |
| } |
| |
| /* Returns true if REF is independent on all other accessess in LOOP. |
| KIND specifies the kind of dependence to consider. |
| lim_raw assumes REF is not stored in LOOP and disambiguates RAW |
| dependences so if true REF can be hoisted out of LOOP |
| sm_war disambiguates a store REF against all other loads to see |
| whether the store can be sunk across loads out of LOOP |
| sm_waw disambiguates a store REF against all other stores to see |
| whether the store can be sunk across stores out of LOOP. */ |
| |
| static bool |
| ref_indep_loop_p (class loop *loop, im_mem_ref *ref, dep_kind kind) |
| { |
| bool indep_p = true; |
| bitmap refs_to_check; |
| |
| if (kind == sm_war) |
| refs_to_check = &memory_accesses.refs_loaded_in_loop[loop->num]; |
| else |
| refs_to_check = &memory_accesses.refs_stored_in_loop[loop->num]; |
| |
| if (bitmap_bit_p (refs_to_check, UNANALYZABLE_MEM_ID) |
| || ref->mem.ref == error_mark_node) |
| indep_p = false; |
| else |
| { |
| /* tri-state, { unknown, independent, dependent } */ |
| dep_state state = query_loop_dependence (loop, ref, kind); |
| if (state != dep_unknown) |
| return state == dep_independent ? true : false; |
| |
| class loop *inner = loop->inner; |
| while (inner) |
| { |
| if (!ref_indep_loop_p (inner, ref, kind)) |
| { |
| indep_p = false; |
| break; |
| } |
| inner = inner->next; |
| } |
| |
| if (indep_p) |
| { |
| unsigned i; |
| bitmap_iterator bi; |
| EXECUTE_IF_SET_IN_BITMAP (refs_to_check, 0, i, bi) |
| { |
| im_mem_ref *aref = memory_accesses.refs_list[i]; |
| if (aref->mem.ref == error_mark_node) |
| { |
| gimple *stmt = aref->accesses_in_loop[0].stmt; |
| if ((kind == sm_war |
| && ref_maybe_used_by_stmt_p (stmt, &ref->mem, |
| kind != sm_waw)) |
| || stmt_may_clobber_ref_p_1 (stmt, &ref->mem, |
| kind != sm_waw)) |
| { |
| indep_p = false; |
| break; |
| } |
| } |
| else if (!refs_independent_p (ref, aref, kind != sm_waw)) |
| { |
| indep_p = false; |
| break; |
| } |
| } |
| } |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "Querying %s dependencies of ref %u in loop %d: %s\n", |
| kind == lim_raw ? "RAW" : (kind == sm_war ? "SM WAR" : "SM WAW"), |
| ref->id, loop->num, indep_p ? "independent" : "dependent"); |
| |
| /* Record the computed result in the cache. */ |
| record_loop_dependence (loop, ref, kind, |
| indep_p ? dep_independent : dep_dependent); |
| |
| return indep_p; |
| } |
| |
| class ref_in_loop_hot_body |
| { |
| public: |
| ref_in_loop_hot_body (class loop *loop_) : l (loop_) {} |
| bool operator () (mem_ref_loc *loc); |
| class loop *l; |
| }; |
| |
| /* Check the coldest loop between loop L and innermost loop. If there is one |
| cold loop between L and INNER_LOOP, store motion can be performed, otherwise |
| no cold loop means no store motion. get_coldest_out_loop also handles cases |
| when l is inner_loop. */ |
| bool |
| ref_in_loop_hot_body::operator () (mem_ref_loc *loc) |
| { |
| basic_block curr_bb = gimple_bb (loc->stmt); |
| class loop *inner_loop = curr_bb->loop_father; |
| return get_coldest_out_loop (l, inner_loop, curr_bb); |
| } |
| |
| |
| /* Returns true if we can perform store motion of REF from LOOP. */ |
| |
| static bool |
| can_sm_ref_p |