| /* Full and partial redundancy elimination and code hoisting on SSA GIMPLE. |
| Copyright (C) 2001-2021 Free Software Foundation, Inc. |
| Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher |
| <stevenb@suse.de> |
| |
| 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 "rtl.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "predict.h" |
| #include "alloc-pool.h" |
| #include "tree-pass.h" |
| #include "ssa.h" |
| #include "cgraph.h" |
| #include "gimple-pretty-print.h" |
| #include "fold-const.h" |
| #include "cfganal.h" |
| #include "gimple-fold.h" |
| #include "tree-eh.h" |
| #include "gimplify.h" |
| #include "gimple-iterator.h" |
| #include "tree-cfg.h" |
| #include "tree-into-ssa.h" |
| #include "tree-dfa.h" |
| #include "tree-ssa.h" |
| #include "cfgloop.h" |
| #include "tree-ssa-sccvn.h" |
| #include "tree-scalar-evolution.h" |
| #include "dbgcnt.h" |
| #include "domwalk.h" |
| #include "tree-ssa-propagate.h" |
| #include "tree-ssa-dce.h" |
| #include "tree-cfgcleanup.h" |
| #include "alias.h" |
| |
| /* Even though this file is called tree-ssa-pre.c, we actually |
| implement a bit more than just PRE here. All of them piggy-back |
| on GVN which is implemented in tree-ssa-sccvn.c. |
| |
| 1. Full Redundancy Elimination (FRE) |
| This is the elimination phase of GVN. |
| |
| 2. Partial Redundancy Elimination (PRE) |
| This is adds computation of AVAIL_OUT and ANTIC_IN and |
| doing expression insertion to form GVN-PRE. |
| |
| 3. Code hoisting |
| This optimization uses the ANTIC_IN sets computed for PRE |
| to move expressions further up than PRE would do, to make |
| multiple computations of the same value fully redundant. |
| This pass is explained below (after the explanation of the |
| basic algorithm for PRE). |
| */ |
| |
| /* TODO: |
| |
| 1. Avail sets can be shared by making an avail_find_leader that |
| walks up the dominator tree and looks in those avail sets. |
| This might affect code optimality, it's unclear right now. |
| Currently the AVAIL_OUT sets are the remaining quadraticness in |
| memory of GVN-PRE. |
| 2. Strength reduction can be performed by anticipating expressions |
| we can repair later on. |
| 3. We can do back-substitution or smarter value numbering to catch |
| commutative expressions split up over multiple statements. |
| */ |
| |
| /* For ease of terminology, "expression node" in the below refers to |
| every expression node but GIMPLE_ASSIGN, because GIMPLE_ASSIGNs |
| represent the actual statement containing the expressions we care about, |
| and we cache the value number by putting it in the expression. */ |
| |
| /* Basic algorithm for Partial Redundancy Elimination: |
| |
| First we walk the statements to generate the AVAIL sets, the |
| EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the |
| generation of values/expressions by a given block. We use them |
| when computing the ANTIC sets. The AVAIL sets consist of |
| SSA_NAME's that represent values, so we know what values are |
| available in what blocks. AVAIL is a forward dataflow problem. In |
| SSA, values are never killed, so we don't need a kill set, or a |
| fixpoint iteration, in order to calculate the AVAIL sets. In |
| traditional parlance, AVAIL sets tell us the downsafety of the |
| expressions/values. |
| |
| Next, we generate the ANTIC sets. These sets represent the |
| anticipatable expressions. ANTIC is a backwards dataflow |
| problem. An expression is anticipatable in a given block if it could |
| be generated in that block. This means that if we had to perform |
| an insertion in that block, of the value of that expression, we |
| could. Calculating the ANTIC sets requires phi translation of |
| expressions, because the flow goes backwards through phis. We must |
| iterate to a fixpoint of the ANTIC sets, because we have a kill |
| set. Even in SSA form, values are not live over the entire |
| function, only from their definition point onwards. So we have to |
| remove values from the ANTIC set once we go past the definition |
| point of the leaders that make them up. |
| compute_antic/compute_antic_aux performs this computation. |
| |
| Third, we perform insertions to make partially redundant |
| expressions fully redundant. |
| |
| An expression is partially redundant (excluding partial |
| anticipation) if: |
| |
| 1. It is AVAIL in some, but not all, of the predecessors of a |
| given block. |
| 2. It is ANTIC in all the predecessors. |
| |
| In order to make it fully redundant, we insert the expression into |
| the predecessors where it is not available, but is ANTIC. |
| |
| When optimizing for size, we only eliminate the partial redundancy |
| if we need to insert in only one predecessor. This avoids almost |
| completely the code size increase that PRE usually causes. |
| |
| For the partial anticipation case, we only perform insertion if it |
| is partially anticipated in some block, and fully available in all |
| of the predecessors. |
| |
| do_pre_regular_insertion/do_pre_partial_partial_insertion |
| performs these steps, driven by insert/insert_aux. |
| |
| Fourth, we eliminate fully redundant expressions. |
| This is a simple statement walk that replaces redundant |
| calculations with the now available values. */ |
| |
| /* Basic algorithm for Code Hoisting: |
| |
| Code hoisting is: Moving value computations up in the control flow |
| graph to make multiple copies redundant. Typically this is a size |
| optimization, but there are cases where it also is helpful for speed. |
| |
| A simple code hoisting algorithm is implemented that piggy-backs on |
| the PRE infrastructure. For code hoisting, we have to know ANTIC_OUT |
| which is effectively ANTIC_IN - AVAIL_OUT. The latter two have to be |
| computed for PRE, and we can use them to perform a limited version of |
| code hoisting, too. |
| |
| For the purpose of this implementation, a value is hoistable to a basic |
| block B if the following properties are met: |
| |
| 1. The value is in ANTIC_IN(B) -- the value will be computed on all |
| paths from B to function exit and it can be computed in B); |
| |
| 2. The value is not in AVAIL_OUT(B) -- there would be no need to |
| compute the value again and make it available twice; |
| |
| 3. All successors of B are dominated by B -- makes sure that inserting |
| a computation of the value in B will make the remaining |
| computations fully redundant; |
| |
| 4. At least one successor has the value in AVAIL_OUT -- to avoid |
| hoisting values up too far; |
| |
| 5. There are at least two successors of B -- hoisting in straight |
| line code is pointless. |
| |
| The third condition is not strictly necessary, but it would complicate |
| the hoisting pass a lot. In fact, I don't know of any code hoisting |
| algorithm that does not have this requirement. Fortunately, experiments |
| have show that most candidate hoistable values are in regions that meet |
| this condition (e.g. diamond-shape regions). |
| |
| The forth condition is necessary to avoid hoisting things up too far |
| away from the uses of the value. Nothing else limits the algorithm |
| from hoisting everything up as far as ANTIC_IN allows. Experiments |
| with SPEC and CSiBE have shown that hoisting up too far results in more |
| spilling, less benefits for code size, and worse benchmark scores. |
| Fortunately, in practice most of the interesting hoisting opportunities |
| are caught despite this limitation. |
| |
| For hoistable values that meet all conditions, expressions are inserted |
| to make the calculation of the hoistable value fully redundant. We |
| perform code hoisting insertions after each round of PRE insertions, |
| because code hoisting never exposes new PRE opportunities, but PRE can |
| create new code hoisting opportunities. |
| |
| The code hoisting algorithm is implemented in do_hoist_insert, driven |
| by insert/insert_aux. */ |
| |
| /* Representations of value numbers: |
| |
| Value numbers are represented by a representative SSA_NAME. We |
| will create fake SSA_NAME's in situations where we need a |
| representative but do not have one (because it is a complex |
| expression). In order to facilitate storing the value numbers in |
| bitmaps, and keep the number of wasted SSA_NAME's down, we also |
| associate a value_id with each value number, and create full blown |
| ssa_name's only where we actually need them (IE in operands of |
| existing expressions). |
| |
| Theoretically you could replace all the value_id's with |
| SSA_NAME_VERSION, but this would allocate a large number of |
| SSA_NAME's (which are each > 30 bytes) just to get a 4 byte number. |
| It would also require an additional indirection at each point we |
| use the value id. */ |
| |
| /* Representation of expressions on value numbers: |
| |
| Expressions consisting of value numbers are represented the same |
| way as our VN internally represents them, with an additional |
| "pre_expr" wrapping around them in order to facilitate storing all |
| of the expressions in the same sets. */ |
| |
| /* Representation of sets: |
| |
| The dataflow sets do not need to be sorted in any particular order |
| for the majority of their lifetime, are simply represented as two |
| bitmaps, one that keeps track of values present in the set, and one |
| that keeps track of expressions present in the set. |
| |
| When we need them in topological order, we produce it on demand by |
| transforming the bitmap into an array and sorting it into topo |
| order. */ |
| |
| /* Type of expression, used to know which member of the PRE_EXPR union |
| is valid. */ |
| |
| enum pre_expr_kind |
| { |
| NAME, |
| NARY, |
| REFERENCE, |
| CONSTANT |
| }; |
| |
| union pre_expr_union |
| { |
| tree name; |
| tree constant; |
| vn_nary_op_t nary; |
| vn_reference_t reference; |
| }; |
| |
| typedef struct pre_expr_d : nofree_ptr_hash <pre_expr_d> |
| { |
| enum pre_expr_kind kind; |
| unsigned int id; |
| unsigned value_id; |
| location_t loc; |
| pre_expr_union u; |
| |
| /* hash_table support. */ |
| static inline hashval_t hash (const pre_expr_d *); |
| static inline int equal (const pre_expr_d *, const pre_expr_d *); |
| } *pre_expr; |
| |
| #define PRE_EXPR_NAME(e) (e)->u.name |
| #define PRE_EXPR_NARY(e) (e)->u.nary |
| #define PRE_EXPR_REFERENCE(e) (e)->u.reference |
| #define PRE_EXPR_CONSTANT(e) (e)->u.constant |
| |
| /* Compare E1 and E1 for equality. */ |
| |
| inline int |
| pre_expr_d::equal (const pre_expr_d *e1, const pre_expr_d *e2) |
| { |
| if (e1->kind != e2->kind) |
| return false; |
| |
| switch (e1->kind) |
| { |
| case CONSTANT: |
| return vn_constant_eq_with_type (PRE_EXPR_CONSTANT (e1), |
| PRE_EXPR_CONSTANT (e2)); |
| case NAME: |
| return PRE_EXPR_NAME (e1) == PRE_EXPR_NAME (e2); |
| case NARY: |
| return vn_nary_op_eq (PRE_EXPR_NARY (e1), PRE_EXPR_NARY (e2)); |
| case REFERENCE: |
| return vn_reference_eq (PRE_EXPR_REFERENCE (e1), |
| PRE_EXPR_REFERENCE (e2)); |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* Hash E. */ |
| |
| inline hashval_t |
| pre_expr_d::hash (const pre_expr_d *e) |
| { |
| switch (e->kind) |
| { |
| case CONSTANT: |
| return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e)); |
| case NAME: |
| return SSA_NAME_VERSION (PRE_EXPR_NAME (e)); |
| case NARY: |
| return PRE_EXPR_NARY (e)->hashcode; |
| case REFERENCE: |
| return PRE_EXPR_REFERENCE (e)->hashcode; |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* Next global expression id number. */ |
| static unsigned int next_expression_id; |
| |
| /* Mapping from expression to id number we can use in bitmap sets. */ |
| static vec<pre_expr> expressions; |
| static hash_table<pre_expr_d> *expression_to_id; |
| static vec<unsigned> name_to_id; |
| |
| /* Allocate an expression id for EXPR. */ |
| |
| static inline unsigned int |
| alloc_expression_id (pre_expr expr) |
| { |
| struct pre_expr_d **slot; |
| /* Make sure we won't overflow. */ |
| gcc_assert (next_expression_id + 1 > next_expression_id); |
| expr->id = next_expression_id++; |
| expressions.safe_push (expr); |
| if (expr->kind == NAME) |
| { |
| unsigned version = SSA_NAME_VERSION (PRE_EXPR_NAME (expr)); |
| /* vec::safe_grow_cleared allocates no headroom. Avoid frequent |
| re-allocations by using vec::reserve upfront. */ |
| unsigned old_len = name_to_id.length (); |
| name_to_id.reserve (num_ssa_names - old_len); |
| name_to_id.quick_grow_cleared (num_ssa_names); |
| gcc_assert (name_to_id[version] == 0); |
| name_to_id[version] = expr->id; |
| } |
| else |
| { |
| slot = expression_to_id->find_slot (expr, INSERT); |
| gcc_assert (!*slot); |
| *slot = expr; |
| } |
| return next_expression_id - 1; |
| } |
| |
| /* Return the expression id for tree EXPR. */ |
| |
| static inline unsigned int |
| get_expression_id (const pre_expr expr) |
| { |
| return expr->id; |
| } |
| |
| static inline unsigned int |
| lookup_expression_id (const pre_expr expr) |
| { |
| struct pre_expr_d **slot; |
| |
| if (expr->kind == NAME) |
| { |
| unsigned version = SSA_NAME_VERSION (PRE_EXPR_NAME (expr)); |
| if (name_to_id.length () <= version) |
| return 0; |
| return name_to_id[version]; |
| } |
| else |
| { |
| slot = expression_to_id->find_slot (expr, NO_INSERT); |
| if (!slot) |
| return 0; |
| return ((pre_expr)*slot)->id; |
| } |
| } |
| |
| /* Return the existing expression id for EXPR, or create one if one |
| does not exist yet. */ |
| |
| static inline unsigned int |
| get_or_alloc_expression_id (pre_expr expr) |
| { |
| unsigned int id = lookup_expression_id (expr); |
| if (id == 0) |
| return alloc_expression_id (expr); |
| return expr->id = id; |
| } |
| |
| /* Return the expression that has expression id ID */ |
| |
| static inline pre_expr |
| expression_for_id (unsigned int id) |
| { |
| return expressions[id]; |
| } |
| |
| static object_allocator<pre_expr_d> pre_expr_pool ("pre_expr nodes"); |
| |
| /* Given an SSA_NAME NAME, get or create a pre_expr to represent it. */ |
| |
| static pre_expr |
| get_or_alloc_expr_for_name (tree name) |
| { |
| struct pre_expr_d expr; |
| pre_expr result; |
| unsigned int result_id; |
| |
| expr.kind = NAME; |
| expr.id = 0; |
| PRE_EXPR_NAME (&expr) = name; |
| result_id = lookup_expression_id (&expr); |
| if (result_id != 0) |
| return expression_for_id (result_id); |
| |
| result = pre_expr_pool.allocate (); |
| result->kind = NAME; |
| result->loc = UNKNOWN_LOCATION; |
| result->value_id = VN_INFO (name)->value_id; |
| PRE_EXPR_NAME (result) = name; |
| alloc_expression_id (result); |
| return result; |
| } |
| |
| /* Given an NARY, get or create a pre_expr to represent it. */ |
| |
| static pre_expr |
| get_or_alloc_expr_for_nary (vn_nary_op_t nary, |
| location_t loc = UNKNOWN_LOCATION) |
| { |
| struct pre_expr_d expr; |
| pre_expr result; |
| unsigned int result_id; |
| |
| expr.kind = NARY; |
| expr.id = 0; |
| PRE_EXPR_NARY (&expr) = nary; |
| result_id = lookup_expression_id (&expr); |
| if (result_id != 0) |
| return expression_for_id (result_id); |
| |
| result = pre_expr_pool.allocate (); |
| result->kind = NARY; |
| result->loc = loc; |
| result->value_id = nary->value_id; |
| PRE_EXPR_NARY (result) = nary; |
| alloc_expression_id (result); |
| return result; |
| } |
| |
| /* Given an REFERENCE, get or create a pre_expr to represent it. */ |
| |
| static pre_expr |
| get_or_alloc_expr_for_reference (vn_reference_t reference, |
| location_t loc = UNKNOWN_LOCATION) |
| { |
| struct pre_expr_d expr; |
| pre_expr result; |
| unsigned int result_id; |
| |
| expr.kind = REFERENCE; |
| expr.id = 0; |
| PRE_EXPR_REFERENCE (&expr) = reference; |
| result_id = lookup_expression_id (&expr); |
| if (result_id != 0) |
| return expression_for_id (result_id); |
| |
| result = pre_expr_pool.allocate (); |
| result->kind = REFERENCE; |
| result->loc = loc; |
| result->value_id = reference->value_id; |
| PRE_EXPR_REFERENCE (result) = reference; |
| alloc_expression_id (result); |
| return result; |
| } |
| |
| |
| /* An unordered bitmap set. One bitmap tracks values, the other, |
| expressions. */ |
| typedef class bitmap_set |
| { |
| public: |
| bitmap_head expressions; |
| bitmap_head values; |
| } *bitmap_set_t; |
| |
| #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi) \ |
| EXECUTE_IF_SET_IN_BITMAP (&(set)->expressions, 0, (id), (bi)) |
| |
| #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi) \ |
| EXECUTE_IF_SET_IN_BITMAP (&(set)->values, 0, (id), (bi)) |
| |
| /* Mapping from value id to expressions with that value_id. */ |
| static vec<bitmap> value_expressions; |
| /* We just record a single expression for each constant value, |
| one of kind CONSTANT. */ |
| static vec<pre_expr> constant_value_expressions; |
| |
| |
| /* This structure is used to keep track of statistics on what |
| optimization PRE was able to perform. */ |
| static struct |
| { |
| /* The number of new expressions/temporaries generated by PRE. */ |
| int insertions; |
| |
| /* The number of inserts found due to partial anticipation */ |
| int pa_insert; |
| |
| /* The number of inserts made for code hoisting. */ |
| int hoist_insert; |
| |
| /* The number of new PHI nodes added by PRE. */ |
| int phis; |
| } pre_stats; |
| |
| static bool do_partial_partial; |
| static pre_expr bitmap_find_leader (bitmap_set_t, unsigned int); |
| static void bitmap_value_insert_into_set (bitmap_set_t, pre_expr); |
| static bool bitmap_value_replace_in_set (bitmap_set_t, pre_expr); |
| static void bitmap_set_copy (bitmap_set_t, bitmap_set_t); |
| static bool bitmap_set_contains_value (bitmap_set_t, unsigned int); |
| static void bitmap_insert_into_set (bitmap_set_t, pre_expr); |
| static bitmap_set_t bitmap_set_new (void); |
| static tree create_expression_by_pieces (basic_block, pre_expr, gimple_seq *, |
| tree); |
| static tree find_or_generate_expression (basic_block, tree, gimple_seq *); |
| static unsigned int get_expr_value_id (pre_expr); |
| |
| /* We can add and remove elements and entries to and from sets |
| and hash tables, so we use alloc pools for them. */ |
| |
| static object_allocator<bitmap_set> bitmap_set_pool ("Bitmap sets"); |
| static bitmap_obstack grand_bitmap_obstack; |
| |
| /* A three tuple {e, pred, v} used to cache phi translations in the |
| phi_translate_table. */ |
| |
| typedef struct expr_pred_trans_d : public typed_noop_remove <expr_pred_trans_d> |
| { |
| typedef expr_pred_trans_d value_type; |
| typedef expr_pred_trans_d compare_type; |
| |
| /* The expression ID. */ |
| unsigned e; |
| |
| /* The value expression ID that resulted from the translation. */ |
| unsigned v; |
| |
| /* hash_table support. */ |
| static inline void mark_empty (expr_pred_trans_d &); |
| static inline bool is_empty (const expr_pred_trans_d &); |
| static inline void mark_deleted (expr_pred_trans_d &); |
| static inline bool is_deleted (const expr_pred_trans_d &); |
| static const bool empty_zero_p = true; |
| static inline hashval_t hash (const expr_pred_trans_d &); |
| static inline int equal (const expr_pred_trans_d &, const expr_pred_trans_d &); |
| } *expr_pred_trans_t; |
| typedef const struct expr_pred_trans_d *const_expr_pred_trans_t; |
| |
| inline bool |
| expr_pred_trans_d::is_empty (const expr_pred_trans_d &e) |
| { |
| return e.e == 0; |
| } |
| |
| inline bool |
| expr_pred_trans_d::is_deleted (const expr_pred_trans_d &e) |
| { |
| return e.e == -1u; |
| } |
| |
| inline void |
| expr_pred_trans_d::mark_empty (expr_pred_trans_d &e) |
| { |
| e.e = 0; |
| } |
| |
| inline void |
| expr_pred_trans_d::mark_deleted (expr_pred_trans_d &e) |
| { |
| e.e = -1u; |
| } |
| |
| inline hashval_t |
| expr_pred_trans_d::hash (const expr_pred_trans_d &e) |
| { |
| return e.e; |
| } |
| |
| inline int |
| expr_pred_trans_d::equal (const expr_pred_trans_d &ve1, |
| const expr_pred_trans_d &ve2) |
| { |
| return ve1.e == ve2.e; |
| } |
| |
| /* Sets that we need to keep track of. */ |
| typedef struct bb_bitmap_sets |
| { |
| /* The EXP_GEN set, which represents expressions/values generated in |
| a basic block. */ |
| bitmap_set_t exp_gen; |
| |
| /* The PHI_GEN set, which represents PHI results generated in a |
| basic block. */ |
| bitmap_set_t phi_gen; |
| |
| /* The TMP_GEN set, which represents results/temporaries generated |
| in a basic block. IE the LHS of an expression. */ |
| bitmap_set_t tmp_gen; |
| |
| /* The AVAIL_OUT set, which represents which values are available in |
| a given basic block. */ |
| bitmap_set_t avail_out; |
| |
| /* The ANTIC_IN set, which represents which values are anticipatable |
| in a given basic block. */ |
| bitmap_set_t antic_in; |
| |
| /* The PA_IN set, which represents which values are |
| partially anticipatable in a given basic block. */ |
| bitmap_set_t pa_in; |
| |
| /* The NEW_SETS set, which is used during insertion to augment the |
| AVAIL_OUT set of blocks with the new insertions performed during |
| the current iteration. */ |
| bitmap_set_t new_sets; |
| |
| /* A cache for value_dies_in_block_x. */ |
| bitmap expr_dies; |
| |
| /* The live virtual operand on successor edges. */ |
| tree vop_on_exit; |
| |
| /* PHI translate cache for the single successor edge. */ |
| hash_table<expr_pred_trans_d> *phi_translate_table; |
| |
| /* True if we have visited this block during ANTIC calculation. */ |
| unsigned int visited : 1; |
| |
| /* True when the block contains a call that might not return. */ |
| unsigned int contains_may_not_return_call : 1; |
| } *bb_value_sets_t; |
| |
| #define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen |
| #define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen |
| #define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen |
| #define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out |
| #define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in |
| #define PA_IN(BB) ((bb_value_sets_t) ((BB)->aux))->pa_in |
| #define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets |
| #define EXPR_DIES(BB) ((bb_value_sets_t) ((BB)->aux))->expr_dies |
| #define PHI_TRANS_TABLE(BB) ((bb_value_sets_t) ((BB)->aux))->phi_translate_table |
| #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited |
| #define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call |
| #define BB_LIVE_VOP_ON_EXIT(BB) ((bb_value_sets_t) ((BB)->aux))->vop_on_exit |
| |
| |
| /* Add the tuple mapping from {expression E, basic block PRED} to |
| the phi translation table and return whether it pre-existed. */ |
| |
| static inline bool |
| phi_trans_add (expr_pred_trans_t *entry, pre_expr e, basic_block pred) |
| { |
| if (!PHI_TRANS_TABLE (pred)) |
| PHI_TRANS_TABLE (pred) = new hash_table<expr_pred_trans_d> (11); |
| |
| expr_pred_trans_t slot; |
| expr_pred_trans_d tem; |
| unsigned id = get_expression_id (e); |
| tem.e = id; |
| slot = PHI_TRANS_TABLE (pred)->find_slot_with_hash (tem, id, INSERT); |
| if (slot->e) |
| { |
| *entry = slot; |
| return true; |
| } |
| |
| *entry = slot; |
| slot->e = id; |
| return false; |
| } |
| |
| |
| /* Add expression E to the expression set of value id V. */ |
| |
| static void |
| add_to_value (unsigned int v, pre_expr e) |
| { |
| gcc_checking_assert (get_expr_value_id (e) == v); |
| |
| if (value_id_constant_p (v)) |
| { |
| if (e->kind != CONSTANT) |
| return; |
| |
| if (-v >= constant_value_expressions.length ()) |
| constant_value_expressions.safe_grow_cleared (-v + 1); |
| |
| pre_expr leader = constant_value_expressions[-v]; |
| if (!leader) |
| constant_value_expressions[-v] = e; |
| } |
| else |
| { |
| if (v >= value_expressions.length ()) |
| value_expressions.safe_grow_cleared (v + 1); |
| |
| bitmap set = value_expressions[v]; |
| if (!set) |
| { |
| set = BITMAP_ALLOC (&grand_bitmap_obstack); |
| value_expressions[v] = set; |
| } |
| bitmap_set_bit (set, get_or_alloc_expression_id (e)); |
| } |
| } |
| |
| /* Create a new bitmap set and return it. */ |
| |
| static bitmap_set_t |
| bitmap_set_new (void) |
| { |
| bitmap_set_t ret = bitmap_set_pool.allocate (); |
| bitmap_initialize (&ret->expressions, &grand_bitmap_obstack); |
| bitmap_initialize (&ret->values, &grand_bitmap_obstack); |
| return ret; |
| } |
| |
| /* Return the value id for a PRE expression EXPR. */ |
| |
| static unsigned int |
| get_expr_value_id (pre_expr expr) |
| { |
| /* ??? We cannot assert that expr has a value-id (it can be 0), because |
| we assign value-ids only to expressions that have a result |
| in set_hashtable_value_ids. */ |
| return expr->value_id; |
| } |
| |
| /* Return a VN valnum (SSA name or constant) for the PRE value-id VAL. */ |
| |
| static tree |
| vn_valnum_from_value_id (unsigned int val) |
| { |
| if (value_id_constant_p (val)) |
| { |
| pre_expr vexpr = constant_value_expressions[-val]; |
| if (vexpr) |
| return PRE_EXPR_CONSTANT (vexpr); |
| return NULL_TREE; |
| } |
| |
| bitmap exprset = value_expressions[val]; |
| bitmap_iterator bi; |
| unsigned int i; |
| EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi) |
| { |
| pre_expr vexpr = expression_for_id (i); |
| if (vexpr->kind == NAME) |
| return VN_INFO (PRE_EXPR_NAME (vexpr))->valnum; |
| } |
| return NULL_TREE; |
| } |
| |
| /* Insert an expression EXPR into a bitmapped set. */ |
| |
| static void |
| bitmap_insert_into_set (bitmap_set_t set, pre_expr expr) |
| { |
| unsigned int val = get_expr_value_id (expr); |
| if (! value_id_constant_p (val)) |
| { |
| /* Note this is the only function causing multiple expressions |
| for the same value to appear in a set. This is needed for |
| TMP_GEN, PHI_GEN and NEW_SETs. */ |
| bitmap_set_bit (&set->values, val); |
| bitmap_set_bit (&set->expressions, get_or_alloc_expression_id (expr)); |
| } |
| } |
| |
| /* Copy a bitmapped set ORIG, into bitmapped set DEST. */ |
| |
| static void |
| bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig) |
| { |
| bitmap_copy (&dest->expressions, &orig->expressions); |
| bitmap_copy (&dest->values, &orig->values); |
| } |
| |
| |
| /* Free memory used up by SET. */ |
| static void |
| bitmap_set_free (bitmap_set_t set) |
| { |
| bitmap_clear (&set->expressions); |
| bitmap_clear (&set->values); |
| } |
| |
| static void |
| pre_expr_DFS (pre_expr expr, bitmap_set_t set, bitmap val_visited, |
| vec<pre_expr> &post); |
| |
| /* DFS walk leaders of VAL to their operands with leaders in SET, collecting |
| expressions in SET in postorder into POST. */ |
| |
| static void |
| pre_expr_DFS (unsigned val, bitmap_set_t set, bitmap val_visited, |
| vec<pre_expr> &post) |
| { |
| unsigned int i; |
| bitmap_iterator bi; |
| |
| /* Iterate over all leaders and DFS recurse. Borrowed from |
| bitmap_find_leader. */ |
| bitmap exprset = value_expressions[val]; |
| if (!exprset->first->next) |
| { |
| EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi) |
| if (bitmap_bit_p (&set->expressions, i)) |
| pre_expr_DFS (expression_for_id (i), set, val_visited, post); |
| return; |
| } |
| |
| EXECUTE_IF_AND_IN_BITMAP (exprset, &set->expressions, 0, i, bi) |
| pre_expr_DFS (expression_for_id (i), set, val_visited, post); |
| } |
| |
| /* DFS walk EXPR to its operands with leaders in SET, collecting |
| expressions in SET in postorder into POST. */ |
| |
| static void |
| pre_expr_DFS (pre_expr expr, bitmap_set_t set, bitmap val_visited, |
| vec<pre_expr> &post) |
| { |
| switch (expr->kind) |
| { |
| case NARY: |
| { |
| vn_nary_op_t nary = PRE_EXPR_NARY (expr); |
| for (unsigned i = 0; i < nary->length; i++) |
| { |
| if (TREE_CODE (nary->op[i]) != SSA_NAME) |
| continue; |
| unsigned int op_val_id = VN_INFO (nary->op[i])->value_id; |
| /* If we already found a leader for the value we've |
| recursed already. Avoid the costly bitmap_find_leader. */ |
| if (bitmap_bit_p (&set->values, op_val_id) |
| && bitmap_set_bit (val_visited, op_val_id)) |
| pre_expr_DFS (op_val_id, set, val_visited, post); |
| } |
| break; |
| } |
| case REFERENCE: |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (expr); |
| vec<vn_reference_op_s> operands = ref->operands; |
| vn_reference_op_t operand; |
| for (unsigned i = 0; operands.iterate (i, &operand); i++) |
| { |
| tree op[3]; |
| op[0] = operand->op0; |
| op[1] = operand->op1; |
| op[2] = operand->op2; |
| for (unsigned n = 0; n < 3; ++n) |
| { |
| if (!op[n] || TREE_CODE (op[n]) != SSA_NAME) |
| continue; |
| unsigned op_val_id = VN_INFO (op[n])->value_id; |
| if (bitmap_bit_p (&set->values, op_val_id) |
| && bitmap_set_bit (val_visited, op_val_id)) |
| pre_expr_DFS (op_val_id, set, val_visited, post); |
| } |
| } |
| break; |
| } |
| default:; |
| } |
| post.quick_push (expr); |
| } |
| |
| /* Generate an topological-ordered array of bitmap set SET. */ |
| |
| static vec<pre_expr> |
| sorted_array_from_bitmap_set (bitmap_set_t set) |
| { |
| unsigned int i; |
| bitmap_iterator bi; |
| vec<pre_expr> result; |
| |
| /* Pre-allocate enough space for the array. */ |
| result.create (bitmap_count_bits (&set->expressions)); |
| |
| auto_bitmap val_visited (&grand_bitmap_obstack); |
| bitmap_tree_view (val_visited); |
| FOR_EACH_VALUE_ID_IN_SET (set, i, bi) |
| if (bitmap_set_bit (val_visited, i)) |
| pre_expr_DFS (i, set, val_visited, result); |
| |
| return result; |
| } |
| |
| /* Subtract all expressions contained in ORIG from DEST. */ |
| |
| static bitmap_set_t |
| bitmap_set_subtract_expressions (bitmap_set_t dest, bitmap_set_t orig) |
| { |
| bitmap_set_t result = bitmap_set_new (); |
| bitmap_iterator bi; |
| unsigned int i; |
| |
| bitmap_and_compl (&result->expressions, &dest->expressions, |
| &orig->expressions); |
| |
| FOR_EACH_EXPR_ID_IN_SET (result, i, bi) |
| { |
| pre_expr expr = expression_for_id (i); |
| unsigned int value_id = get_expr_value_id (expr); |
| bitmap_set_bit (&result->values, value_id); |
| } |
| |
| return result; |
| } |
| |
| /* Subtract all values in bitmap set B from bitmap set A. */ |
| |
| static void |
| bitmap_set_subtract_values (bitmap_set_t a, bitmap_set_t b) |
| { |
| unsigned int i; |
| bitmap_iterator bi; |
| unsigned to_remove = -1U; |
| bitmap_and_compl_into (&a->values, &b->values); |
| FOR_EACH_EXPR_ID_IN_SET (a, i, bi) |
| { |
| if (to_remove != -1U) |
| { |
| bitmap_clear_bit (&a->expressions, to_remove); |
| to_remove = -1U; |
| } |
| pre_expr expr = expression_for_id (i); |
| if (! bitmap_bit_p (&a->values, get_expr_value_id (expr))) |
| to_remove = i; |
| } |
| if (to_remove != -1U) |
| bitmap_clear_bit (&a->expressions, to_remove); |
| } |
| |
| |
| /* Return true if bitmapped set SET contains the value VALUE_ID. */ |
| |
| static bool |
| bitmap_set_contains_value (bitmap_set_t set, unsigned int value_id) |
| { |
| if (value_id_constant_p (value_id)) |
| return true; |
| |
| return bitmap_bit_p (&set->values, value_id); |
| } |
| |
| /* Return true if two bitmap sets are equal. */ |
| |
| static bool |
| bitmap_set_equal (bitmap_set_t a, bitmap_set_t b) |
| { |
| return bitmap_equal_p (&a->values, &b->values); |
| } |
| |
| /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists, |
| and add it otherwise. Return true if any changes were made. */ |
| |
| static bool |
| bitmap_value_replace_in_set (bitmap_set_t set, pre_expr expr) |
| { |
| unsigned int val = get_expr_value_id (expr); |
| if (value_id_constant_p (val)) |
| return false; |
| |
| if (bitmap_set_contains_value (set, val)) |
| { |
| /* The number of expressions having a given value is usually |
| significantly less than the total number of expressions in SET. |
| Thus, rather than check, for each expression in SET, whether it |
| has the value LOOKFOR, we walk the reverse mapping that tells us |
| what expressions have a given value, and see if any of those |
| expressions are in our set. For large testcases, this is about |
| 5-10x faster than walking the bitmap. If this is somehow a |
| significant lose for some cases, we can choose which set to walk |
| based on the set size. */ |
| unsigned int i; |
| bitmap_iterator bi; |
| bitmap exprset = value_expressions[val]; |
| EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi) |
| { |
| if (bitmap_clear_bit (&set->expressions, i)) |
| { |
| bitmap_set_bit (&set->expressions, get_expression_id (expr)); |
| return i != get_expression_id (expr); |
| } |
| } |
| gcc_unreachable (); |
| } |
| |
| bitmap_insert_into_set (set, expr); |
| return true; |
| } |
| |
| /* Insert EXPR into SET if EXPR's value is not already present in |
| SET. */ |
| |
| static void |
| bitmap_value_insert_into_set (bitmap_set_t set, pre_expr expr) |
| { |
| unsigned int val = get_expr_value_id (expr); |
| |
| gcc_checking_assert (expr->id == get_or_alloc_expression_id (expr)); |
| |
| /* Constant values are always considered to be part of the set. */ |
| if (value_id_constant_p (val)) |
| return; |
| |
| /* If the value membership changed, add the expression. */ |
| if (bitmap_set_bit (&set->values, val)) |
| bitmap_set_bit (&set->expressions, expr->id); |
| } |
| |
| /* Print out EXPR to outfile. */ |
| |
| static void |
| print_pre_expr (FILE *outfile, const pre_expr expr) |
| { |
| if (! expr) |
| { |
| fprintf (outfile, "NULL"); |
| return; |
| } |
| switch (expr->kind) |
| { |
| case CONSTANT: |
| print_generic_expr (outfile, PRE_EXPR_CONSTANT (expr)); |
| break; |
| case NAME: |
| print_generic_expr (outfile, PRE_EXPR_NAME (expr)); |
| break; |
| case NARY: |
| { |
| unsigned int i; |
| vn_nary_op_t nary = PRE_EXPR_NARY (expr); |
| fprintf (outfile, "{%s,", get_tree_code_name (nary->opcode)); |
| for (i = 0; i < nary->length; i++) |
| { |
| print_generic_expr (outfile, nary->op[i]); |
| if (i != (unsigned) nary->length - 1) |
| fprintf (outfile, ","); |
| } |
| fprintf (outfile, "}"); |
| } |
| break; |
| |
| case REFERENCE: |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (expr); |
| print_vn_reference_ops (outfile, ref->operands); |
| if (ref->vuse) |
| { |
| fprintf (outfile, "@"); |
| print_generic_expr (outfile, ref->vuse); |
| } |
| } |
| break; |
| } |
| } |
| void debug_pre_expr (pre_expr); |
| |
| /* Like print_pre_expr but always prints to stderr. */ |
| DEBUG_FUNCTION void |
| debug_pre_expr (pre_expr e) |
| { |
| print_pre_expr (stderr, e); |
| fprintf (stderr, "\n"); |
| } |
| |
| /* Print out SET to OUTFILE. */ |
| |
| static void |
| print_bitmap_set (FILE *outfile, bitmap_set_t set, |
| const char *setname, int blockindex) |
| { |
| fprintf (outfile, "%s[%d] := { ", setname, blockindex); |
| if (set) |
| { |
| bool first = true; |
| unsigned i; |
| bitmap_iterator bi; |
| |
| FOR_EACH_EXPR_ID_IN_SET (set, i, bi) |
| { |
| const pre_expr expr = expression_for_id (i); |
| |
| if (!first) |
| fprintf (outfile, ", "); |
| first = false; |
| print_pre_expr (outfile, expr); |
| |
| fprintf (outfile, " (%04d)", get_expr_value_id (expr)); |
| } |
| } |
| fprintf (outfile, " }\n"); |
| } |
| |
| void debug_bitmap_set (bitmap_set_t); |
| |
| DEBUG_FUNCTION void |
| debug_bitmap_set (bitmap_set_t set) |
| { |
| print_bitmap_set (stderr, set, "debug", 0); |
| } |
| |
| void debug_bitmap_sets_for (basic_block); |
| |
| DEBUG_FUNCTION void |
| debug_bitmap_sets_for (basic_block bb) |
| { |
| print_bitmap_set (stderr, AVAIL_OUT (bb), "avail_out", bb->index); |
| print_bitmap_set (stderr, EXP_GEN (bb), "exp_gen", bb->index); |
| print_bitmap_set (stderr, PHI_GEN (bb), "phi_gen", bb->index); |
| print_bitmap_set (stderr, TMP_GEN (bb), "tmp_gen", bb->index); |
| print_bitmap_set (stderr, ANTIC_IN (bb), "antic_in", bb->index); |
| if (do_partial_partial) |
| print_bitmap_set (stderr, PA_IN (bb), "pa_in", bb->index); |
| print_bitmap_set (stderr, NEW_SETS (bb), "new_sets", bb->index); |
| } |
| |
| /* Print out the expressions that have VAL to OUTFILE. */ |
| |
| static void |
| print_value_expressions (FILE *outfile, unsigned int val) |
| { |
| bitmap set = value_expressions[val]; |
| if (set) |
| { |
| bitmap_set x; |
| char s[10]; |
| sprintf (s, "%04d", val); |
| x.expressions = *set; |
| print_bitmap_set (outfile, &x, s, 0); |
| } |
| } |
| |
| |
| DEBUG_FUNCTION void |
| debug_value_expressions (unsigned int val) |
| { |
| print_value_expressions (stderr, val); |
| } |
| |
| /* Given a CONSTANT, allocate a new CONSTANT type PRE_EXPR to |
| represent it. */ |
| |
| static pre_expr |
| get_or_alloc_expr_for_constant (tree constant) |
| { |
| unsigned int result_id; |
| struct pre_expr_d expr; |
| pre_expr newexpr; |
| |
| expr.kind = CONSTANT; |
| PRE_EXPR_CONSTANT (&expr) = constant; |
| result_id = lookup_expression_id (&expr); |
| if (result_id != 0) |
| return expression_for_id (result_id); |
| |
| newexpr = pre_expr_pool.allocate (); |
| newexpr->kind = CONSTANT; |
| newexpr->loc = UNKNOWN_LOCATION; |
| PRE_EXPR_CONSTANT (newexpr) = constant; |
| alloc_expression_id (newexpr); |
| newexpr->value_id = get_or_alloc_constant_value_id (constant); |
| add_to_value (newexpr->value_id, newexpr); |
| return newexpr; |
| } |
| |
| /* Get or allocate a pre_expr for a piece of GIMPLE, and return it. |
| Currently only supports constants and SSA_NAMES. */ |
| static pre_expr |
| get_or_alloc_expr_for (tree t) |
| { |
| if (TREE_CODE (t) == SSA_NAME) |
| return get_or_alloc_expr_for_name (t); |
| else if (is_gimple_min_invariant (t)) |
| return get_or_alloc_expr_for_constant (t); |
| gcc_unreachable (); |
| } |
| |
| /* Return the folded version of T if T, when folded, is a gimple |
| min_invariant or an SSA name. Otherwise, return T. */ |
| |
| static pre_expr |
| fully_constant_expression (pre_expr e) |
| { |
| switch (e->kind) |
| { |
| case CONSTANT: |
| return e; |
| case NARY: |
| { |
| vn_nary_op_t nary = PRE_EXPR_NARY (e); |
| tree res = vn_nary_simplify (nary); |
| if (!res) |
| return e; |
| if (is_gimple_min_invariant (res)) |
| return get_or_alloc_expr_for_constant (res); |
| if (TREE_CODE (res) == SSA_NAME) |
| return get_or_alloc_expr_for_name (res); |
| return e; |
| } |
| case REFERENCE: |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (e); |
| tree folded; |
| if ((folded = fully_constant_vn_reference_p (ref))) |
| return get_or_alloc_expr_for_constant (folded); |
| return e; |
| } |
| default: |
| return e; |
| } |
| return e; |
| } |
| |
| /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that |
| it has the value it would have in BLOCK. Set *SAME_VALID to true |
| in case the new vuse doesn't change the value id of the OPERANDS. */ |
| |
| static tree |
| translate_vuse_through_block (vec<vn_reference_op_s> operands, |
| alias_set_type set, alias_set_type base_set, |
| tree type, tree vuse, |
| basic_block phiblock, |
| basic_block block, bool *same_valid) |
| { |
| gimple *phi = SSA_NAME_DEF_STMT (vuse); |
| ao_ref ref; |
| edge e = NULL; |
| bool use_oracle; |
| |
| if (same_valid) |
| *same_valid = true; |
| |
| if (gimple_bb (phi) != phiblock) |
| return vuse; |
| |
| unsigned int cnt = param_sccvn_max_alias_queries_per_access; |
| use_oracle = ao_ref_init_from_vn_reference (&ref, set, base_set, |
| type, operands); |
| |
| /* Use the alias-oracle to find either the PHI node in this block, |
| the first VUSE used in this block that is equivalent to vuse or |
| the first VUSE which definition in this block kills the value. */ |
| if (gimple_code (phi) == GIMPLE_PHI) |
| e = find_edge (block, phiblock); |
| else if (use_oracle) |
| while (cnt > 0 |
| && !stmt_may_clobber_ref_p_1 (phi, &ref)) |
| { |
| --cnt; |
| vuse = gimple_vuse (phi); |
| phi = SSA_NAME_DEF_STMT (vuse); |
| if (gimple_bb (phi) != phiblock) |
| return vuse; |
| if (gimple_code (phi) == GIMPLE_PHI) |
| { |
| e = find_edge (block, phiblock); |
| break; |
| } |
| } |
| else |
| return NULL_TREE; |
| |
| if (e) |
| { |
| if (use_oracle && same_valid) |
| { |
| bitmap visited = NULL; |
| /* Try to find a vuse that dominates this phi node by skipping |
| non-clobbering statements. */ |
| vuse = get_continuation_for_phi (phi, &ref, true, |
| cnt, &visited, false, NULL, NULL); |
| if (visited) |
| BITMAP_FREE (visited); |
| } |
| else |
| vuse = NULL_TREE; |
| /* If we didn't find any, the value ID can't stay the same. */ |
| if (!vuse && same_valid) |
| *same_valid = false; |
| /* ??? We would like to return vuse here as this is the canonical |
| upmost vdef that this reference is associated with. But during |
| insertion of the references into the hash tables we only ever |
| directly insert with their direct gimple_vuse, hence returning |
| something else would make us not find the other expression. */ |
| return PHI_ARG_DEF (phi, e->dest_idx); |
| } |
| |
| return NULL_TREE; |
| } |
| |
| /* Like bitmap_find_leader, but checks for the value existing in SET1 *or* |
| SET2 *or* SET3. This is used to avoid making a set consisting of the union |
| of PA_IN and ANTIC_IN during insert and phi-translation. */ |
| |
| static inline pre_expr |
| find_leader_in_sets (unsigned int val, bitmap_set_t set1, bitmap_set_t set2, |
| bitmap_set_t set3 = NULL) |
| { |
| pre_expr result = NULL; |
| |
| if (set1) |
| result = bitmap_find_leader (set1, val); |
| if (!result && set2) |
| result = bitmap_find_leader (set2, val); |
| if (!result && set3) |
| result = bitmap_find_leader (set3, val); |
| return result; |
| } |
| |
| /* Get the tree type for our PRE expression e. */ |
| |
| static tree |
| get_expr_type (const pre_expr e) |
| { |
| switch (e->kind) |
| { |
| case NAME: |
| return TREE_TYPE (PRE_EXPR_NAME (e)); |
| case CONSTANT: |
| return TREE_TYPE (PRE_EXPR_CONSTANT (e)); |
| case REFERENCE: |
| return PRE_EXPR_REFERENCE (e)->type; |
| case NARY: |
| return PRE_EXPR_NARY (e)->type; |
| } |
| gcc_unreachable (); |
| } |
| |
| /* Get a representative SSA_NAME for a given expression that is available in B. |
| Since all of our sub-expressions are treated as values, we require |
| them to be SSA_NAME's for simplicity. |
| Prior versions of GVNPRE used to use "value handles" here, so that |
| an expression would be VH.11 + VH.10 instead of d_3 + e_6. In |
| either case, the operands are really values (IE we do not expect |
| them to be usable without finding leaders). */ |
| |
| static tree |
| get_representative_for (const pre_expr e, basic_block b = NULL) |
| { |
| tree name, valnum = NULL_TREE; |
| unsigned int value_id = get_expr_value_id (e); |
| |
| switch (e->kind) |
| { |
| case NAME: |
| return PRE_EXPR_NAME (e); |
| case CONSTANT: |
| return PRE_EXPR_CONSTANT (e); |
| case NARY: |
| case REFERENCE: |
| { |
| /* Go through all of the expressions representing this value |
| and pick out an SSA_NAME. */ |
| unsigned int i; |
| bitmap_iterator bi; |
| bitmap exprs = value_expressions[value_id]; |
| EXECUTE_IF_SET_IN_BITMAP (exprs, 0, i, bi) |
| { |
| pre_expr rep = expression_for_id (i); |
| if (rep->kind == NAME) |
| { |
| tree name = PRE_EXPR_NAME (rep); |
| valnum = VN_INFO (name)->valnum; |
| gimple *def = SSA_NAME_DEF_STMT (name); |
| /* We have to return either a new representative or one |
| that can be used for expression simplification and thus |
| is available in B. */ |
| if (! b |
| || gimple_nop_p (def) |
| || dominated_by_p (CDI_DOMINATORS, b, gimple_bb (def))) |
| return name; |
| } |
| else if (rep->kind == CONSTANT) |
| return PRE_EXPR_CONSTANT (rep); |
| } |
| } |
| break; |
| } |
| |
| /* If we reached here we couldn't find an SSA_NAME. This can |
| happen when we've discovered a value that has never appeared in |
| the program as set to an SSA_NAME, as the result of phi translation. |
| Create one here. |
| ??? We should be able to re-use this when we insert the statement |
| to compute it. */ |
| name = make_temp_ssa_name (get_expr_type (e), gimple_build_nop (), "pretmp"); |
| vn_ssa_aux_t vn_info = VN_INFO (name); |
| vn_info->value_id = value_id; |
| vn_info->valnum = valnum ? valnum : name; |
| /* ??? For now mark this SSA name for release by VN. */ |
| vn_info->needs_insertion = true; |
| add_to_value (value_id, get_or_alloc_expr_for_name (name)); |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Created SSA_NAME representative "); |
| print_generic_expr (dump_file, name); |
| fprintf (dump_file, " for expression:"); |
| print_pre_expr (dump_file, e); |
| fprintf (dump_file, " (%04d)\n", value_id); |
| } |
| |
| return name; |
| } |
| |
| |
| static pre_expr |
| phi_translate (bitmap_set_t, pre_expr, bitmap_set_t, bitmap_set_t, edge); |
| |
| /* Translate EXPR using phis in PHIBLOCK, so that it has the values of |
| the phis in PRED. Return NULL if we can't find a leader for each part |
| of the translated expression. */ |
| |
| static pre_expr |
| phi_translate_1 (bitmap_set_t dest, |
| pre_expr expr, bitmap_set_t set1, bitmap_set_t set2, edge e) |
| { |
| basic_block pred = e->src; |
| basic_block phiblock = e->dest; |
| location_t expr_loc = expr->loc; |
| switch (expr->kind) |
| { |
| case NARY: |
| { |
| unsigned int i; |
| bool changed = false; |
| vn_nary_op_t nary = PRE_EXPR_NARY (expr); |
| vn_nary_op_t newnary = XALLOCAVAR (struct vn_nary_op_s, |
| sizeof_vn_nary_op (nary->length)); |
| memcpy (newnary, nary, sizeof_vn_nary_op (nary->length)); |
| |
| for (i = 0; i < newnary->length; i++) |
| { |
| if (TREE_CODE (newnary->op[i]) != SSA_NAME) |
| continue; |
| else |
| { |
| pre_expr leader, result; |
| unsigned int op_val_id = VN_INFO (newnary->op[i])->value_id; |
| leader = find_leader_in_sets (op_val_id, set1, set2); |
| result = phi_translate (dest, leader, set1, set2, e); |
| if (result && result != leader) |
| /* If op has a leader in the sets we translate make |
| sure to use the value of the translated expression. |
| We might need a new representative for that. */ |
| newnary->op[i] = get_representative_for (result, pred); |
| else if (!result) |
| return NULL; |
| |
| changed |= newnary->op[i] != nary->op[i]; |
| } |
| } |
| if (changed) |
| { |
| pre_expr constant; |
| unsigned int new_val_id; |
| |
| PRE_EXPR_NARY (expr) = newnary; |
| constant = fully_constant_expression (expr); |
| PRE_EXPR_NARY (expr) = nary; |
| if (constant != expr) |
| { |
| /* For non-CONSTANTs we have to make sure we can eventually |
| insert the expression. Which means we need to have a |
| leader for it. */ |
| if (constant->kind != CONSTANT) |
| { |
| /* Do not allow simplifications to non-constants over |
| backedges as this will likely result in a loop PHI node |
| to be inserted and increased register pressure. |
| See PR77498 - this avoids doing predcoms work in |
| a less efficient way. */ |
| if (e->flags & EDGE_DFS_BACK) |
| ; |
| else |
| { |
| unsigned value_id = get_expr_value_id (constant); |
| /* We want a leader in ANTIC_OUT or AVAIL_OUT here. |
| dest has what we computed into ANTIC_OUT sofar |
| so pick from that - since topological sorting |
| by sorted_array_from_bitmap_set isn't perfect |
| we may lose some cases here. */ |
| constant = find_leader_in_sets (value_id, dest, |
| AVAIL_OUT (pred)); |
| if (constant) |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "simplifying "); |
| print_pre_expr (dump_file, expr); |
| fprintf (dump_file, " translated %d -> %d to ", |
| phiblock->index, pred->index); |
| PRE_EXPR_NARY (expr) = newnary; |
| print_pre_expr (dump_file, expr); |
| PRE_EXPR_NARY (expr) = nary; |
| fprintf (dump_file, " to "); |
| print_pre_expr (dump_file, constant); |
| fprintf (dump_file, "\n"); |
| } |
| return constant; |
| } |
| } |
| } |
| else |
| return constant; |
| } |
| |
| /* vn_nary_* do not valueize operands. */ |
| for (i = 0; i < newnary->length; ++i) |
| if (TREE_CODE (newnary->op[i]) == SSA_NAME) |
| newnary->op[i] = VN_INFO (newnary->op[i])->valnum; |
| tree result = vn_nary_op_lookup_pieces (newnary->length, |
| newnary->opcode, |
| newnary->type, |
| &newnary->op[0], |
| &nary); |
| if (result && is_gimple_min_invariant (result)) |
| return get_or_alloc_expr_for_constant (result); |
| |
| if (!nary || nary->predicated_values) |
| { |
| new_val_id = get_next_value_id (); |
| nary = vn_nary_op_insert_pieces (newnary->length, |
| newnary->opcode, |
| newnary->type, |
| &newnary->op[0], |
| result, new_val_id); |
| } |
| expr = get_or_alloc_expr_for_nary (nary, expr_loc); |
| add_to_value (get_expr_value_id (expr), expr); |
| } |
| return expr; |
| } |
| break; |
| |
| case REFERENCE: |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (expr); |
| vec<vn_reference_op_s> operands = ref->operands; |
| tree vuse = ref->vuse; |
| tree newvuse = vuse; |
| vec<vn_reference_op_s> newoperands = vNULL; |
| bool changed = false, same_valid = true; |
| unsigned int i, n; |
| vn_reference_op_t operand; |
| vn_reference_t newref; |
| |
| for (i = 0; operands.iterate (i, &operand); i++) |
| { |
| pre_expr opresult; |
| pre_expr leader; |
| tree op[3]; |
| tree type = operand->type; |
| vn_reference_op_s newop = *operand; |
| op[0] = operand->op0; |
| op[1] = operand->op1; |
| op[2] = operand->op2; |
| for (n = 0; n < 3; ++n) |
| { |
| unsigned int op_val_id; |
| if (!op[n]) |
| continue; |
| if (TREE_CODE (op[n]) != SSA_NAME) |
| { |
| /* We can't possibly insert these. */ |
| if (n != 0 |
| && !is_gimple_min_invariant (op[n])) |
| break; |
| continue; |
| } |
| op_val_id = VN_INFO (op[n])->value_id; |
| leader = find_leader_in_sets (op_val_id, set1, set2); |
| opresult = phi_translate (dest, leader, set1, set2, e); |
| if (opresult && opresult != leader) |
| { |
| tree name = get_representative_for (opresult); |
| changed |= name != op[n]; |
| op[n] = name; |
| } |
| else if (!opresult) |
| break; |
| } |
| if (n != 3) |
| { |
| newoperands.release (); |
| return NULL; |
| } |
| if (!changed) |
| continue; |
| if (!newoperands.exists ()) |
| newoperands = operands.copy (); |
| /* We may have changed from an SSA_NAME to a constant */ |
| if (newop.opcode == SSA_NAME && TREE_CODE (op[0]) != SSA_NAME) |
| newop.opcode = TREE_CODE (op[0]); |
| newop.type = type; |
| newop.op0 = op[0]; |
| newop.op1 = op[1]; |
| newop.op2 = op[2]; |
| newoperands[i] = newop; |
| } |
| gcc_checking_assert (i == operands.length ()); |
| |
| if (vuse) |
| { |
| newvuse = translate_vuse_through_block (newoperands.exists () |
| ? newoperands : operands, |
| ref->set, ref->base_set, |
| ref->type, |
| vuse, phiblock, pred, |
| changed |
| ? NULL : &same_valid); |
| if (newvuse == NULL_TREE) |
| { |
| newoperands.release (); |
| return NULL; |
| } |
| } |
| |
| if (changed || newvuse != vuse) |
| { |
| unsigned int new_val_id; |
| |
| tree result = vn_reference_lookup_pieces (newvuse, ref->set, |
| ref->base_set, |
| ref->type, |
| newoperands.exists () |
| ? newoperands : operands, |
| &newref, VN_WALK); |
| if (result) |
| newoperands.release (); |
| |
| /* We can always insert constants, so if we have a partial |
| redundant constant load of another type try to translate it |
| to a constant of appropriate type. */ |
| if (result && is_gimple_min_invariant (result)) |
| { |
| tree tem = result; |
| if (!useless_type_conversion_p (ref->type, TREE_TYPE (result))) |
| { |
| tem = fold_unary (VIEW_CONVERT_EXPR, ref->type, result); |
| if (tem && !is_gimple_min_invariant (tem)) |
| tem = NULL_TREE; |
| } |
| if (tem) |
| return get_or_alloc_expr_for_constant (tem); |
| } |
| |
| /* If we'd have to convert things we would need to validate |
| if we can insert the translated expression. So fail |
| here for now - we cannot insert an alias with a different |
| type in the VN tables either, as that would assert. */ |
| if (result |
| && !useless_type_conversion_p (ref->type, TREE_TYPE (result))) |
| return NULL; |
| else if (!result && newref |
| && !useless_type_conversion_p (ref->type, newref->type)) |
| { |
| newoperands.release (); |
| return NULL; |
| } |
| |
| if (newref) |
| new_val_id = newref->value_id; |
| else |
| { |
| if (changed || !same_valid) |
| new_val_id = get_next_value_id (); |
| else |
| new_val_id = ref->value_id; |
| if (!newoperands.exists ()) |
| newoperands = operands.copy (); |
| newref = vn_reference_insert_pieces (newvuse, ref->set, |
| ref->base_set, ref->type, |
| newoperands, |
| result, new_val_id); |
| newoperands = vNULL; |
| } |
| expr = get_or_alloc_expr_for_reference (newref, expr_loc); |
| add_to_value (new_val_id, expr); |
| } |
| newoperands.release (); |
| return expr; |
| } |
| break; |
| |
| case NAME: |
| { |
| tree name = PRE_EXPR_NAME (expr); |
| gimple *def_stmt = SSA_NAME_DEF_STMT (name); |
| /* If the SSA name is defined by a PHI node in this block, |
| translate it. */ |
| if (gimple_code (def_stmt) == GIMPLE_PHI |
| && gimple_bb (def_stmt) == phiblock) |
| { |
| tree def = PHI_ARG_DEF (def_stmt, e->dest_idx); |
| |
| /* Handle constant. */ |
| if (is_gimple_min_invariant (def)) |
| return get_or_alloc_expr_for_constant (def); |
| |
| return get_or_alloc_expr_for_name (def); |
| } |
| /* Otherwise return it unchanged - it will get removed if its |
| value is not available in PREDs AVAIL_OUT set of expressions |
| by the subtraction of TMP_GEN. */ |
| return expr; |
| } |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* Wrapper around phi_translate_1 providing caching functionality. */ |
| |
| static pre_expr |
| phi_translate (bitmap_set_t dest, pre_expr expr, |
| bitmap_set_t set1, bitmap_set_t set2, edge e) |
| { |
| expr_pred_trans_t slot = NULL; |
| pre_expr phitrans; |
| |
| if (!expr) |
| return NULL; |
| |
| /* Constants contain no values that need translation. */ |
| if (expr->kind == CONSTANT) |
| return expr; |
| |
| if (value_id_constant_p (get_expr_value_id (expr))) |
| return expr; |
| |
| /* Don't add translations of NAMEs as those are cheap to translate. */ |
| if (expr->kind != NAME) |
| { |
| if (phi_trans_add (&slot, expr, e->src)) |
| return slot->v == 0 ? NULL : expression_for_id (slot->v); |
| /* Store NULL for the value we want to return in the case of |
| recursing. */ |
| slot->v = 0; |
| } |
| |
| /* Translate. */ |
| basic_block saved_valueize_bb = vn_context_bb; |
| vn_context_bb = e->src; |
| phitrans = phi_translate_1 (dest, expr, set1, set2, e); |
| vn_context_bb = saved_valueize_bb; |
| |
| if (slot) |
| { |
| /* We may have reallocated. */ |
| phi_trans_add (&slot, expr, e->src); |
| if (phitrans) |
| slot->v = get_expression_id (phitrans); |
| else |
| /* Remove failed translations again, they cause insert |
| iteration to not pick up new opportunities reliably. */ |
| PHI_TRANS_TABLE (e->src)->clear_slot (slot); |
| } |
| |
| return phitrans; |
| } |
| |
| |
| /* For each expression in SET, translate the values through phi nodes |
| in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting |
| expressions in DEST. */ |
| |
| static void |
| phi_translate_set (bitmap_set_t dest, bitmap_set_t set, edge e) |
| { |
| bitmap_iterator bi; |
| unsigned int i; |
| |
| if (gimple_seq_empty_p (phi_nodes (e->dest))) |
| { |
| bitmap_set_copy (dest, set); |
| return; |
| } |
| |
| /* Allocate the phi-translation cache where we have an idea about |
| its size. hash-table implementation internals tell us that |
| allocating the table to fit twice the number of elements will |
| make sure we do not usually re-allocate. */ |
| if (!PHI_TRANS_TABLE (e->src)) |
| PHI_TRANS_TABLE (e->src) = new hash_table<expr_pred_trans_d> |
| (2 * bitmap_count_bits (&set->expressions)); |
| FOR_EACH_EXPR_ID_IN_SET (set, i, bi) |
| { |
| pre_expr expr = expression_for_id (i); |
| pre_expr translated = phi_translate (dest, expr, set, NULL, e); |
| if (!translated) |
| continue; |
| |
| bitmap_insert_into_set (dest, translated); |
| } |
| } |
| |
| /* Find the leader for a value (i.e., the name representing that |
| value) in a given set, and return it. Return NULL if no leader |
| is found. */ |
| |
| static pre_expr |
| bitmap_find_leader (bitmap_set_t set, unsigned int val) |
| { |
| if (value_id_constant_p (val)) |
| return constant_value_expressions[-val]; |
| |
| if (bitmap_set_contains_value (set, val)) |
| { |
| /* Rather than walk the entire bitmap of expressions, and see |
| whether any of them has the value we are looking for, we look |
| at the reverse mapping, which tells us the set of expressions |
| that have a given value (IE value->expressions with that |
| value) and see if any of those expressions are in our set. |
| The number of expressions per value is usually significantly |
| less than the number of expressions in the set. In fact, for |
| large testcases, doing it this way is roughly 5-10x faster |
| than walking the bitmap. |
| If this is somehow a significant lose for some cases, we can |
| choose which set to walk based on which set is smaller. */ |
| unsigned int i; |
| bitmap_iterator bi; |
| bitmap exprset = value_expressions[val]; |
| |
| if (!exprset->first->next) |
| EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi) |
| if (bitmap_bit_p (&set->expressions, i)) |
| return expression_for_id (i); |
| |
| EXECUTE_IF_AND_IN_BITMAP (exprset, &set->expressions, 0, i, bi) |
| return expression_for_id (i); |
| } |
| return NULL; |
| } |
| |
| /* Determine if EXPR, a memory expression, is ANTIC_IN at the top of |
| BLOCK by seeing if it is not killed in the block. Note that we are |
| only determining whether there is a store that kills it. Because |
| of the order in which clean iterates over values, we are guaranteed |
| that altered operands will have caused us to be eliminated from the |
| ANTIC_IN set already. */ |
| |
| static bool |
| value_dies_in_block_x (pre_expr expr, basic_block block) |
| { |
| tree vuse = PRE_EXPR_REFERENCE (expr)->vuse; |
| vn_reference_t refx = PRE_EXPR_REFERENCE (expr); |
| gimple *def; |
| gimple_stmt_iterator gsi; |
| unsigned id = get_expression_id (expr); |
| bool res = false; |
| ao_ref ref; |
| |
| if (!vuse) |
| return false; |
| |
| /* Lookup a previously calculated result. */ |
| if (EXPR_DIES (block) |
| && bitmap_bit_p (EXPR_DIES (block), id * 2)) |
| return bitmap_bit_p (EXPR_DIES (block), id * 2 + 1); |
| |
| /* A memory expression {e, VUSE} dies in the block if there is a |
| statement that may clobber e. If, starting statement walk from the |
| top of the basic block, a statement uses VUSE there can be no kill |
| inbetween that use and the original statement that loaded {e, VUSE}, |
| so we can stop walking. */ |
| ref.base = NULL_TREE; |
| for (gsi = gsi_start_bb (block); !gsi_end_p (gsi); gsi_next (&gsi)) |
| { |
| tree def_vuse, def_vdef; |
| def = gsi_stmt (gsi); |
| def_vuse = gimple_vuse (def); |
| def_vdef = gimple_vdef (def); |
| |
| /* Not a memory statement. */ |
| if (!def_vuse) |
| continue; |
| |
| /* Not a may-def. */ |
| if (!def_vdef) |
| { |
| /* A load with the same VUSE, we're done. */ |
| if (def_vuse == vuse) |
| break; |
| |
| continue; |
| } |
| |
| /* Init ref only if we really need it. */ |
| if (ref.base == NULL_TREE |
| && !ao_ref_init_from_vn_reference (&ref, refx->set, refx->base_set, |
| refx->type, refx->operands)) |
| { |
| res = true; |
| break; |
| } |
| /* If the statement may clobber expr, it dies. */ |
| if (stmt_may_clobber_ref_p_1 (def, &ref)) |
| { |
| res = true; |
| break; |
| } |
| } |
| |
| /* Remember the result. */ |
| if (!EXPR_DIES (block)) |
| EXPR_DIES (block) = BITMAP_ALLOC (&grand_bitmap_obstack); |
| bitmap_set_bit (EXPR_DIES (block), id * 2); |
| if (res) |
| bitmap_set_bit (EXPR_DIES (block), id * 2 + 1); |
| |
| return res; |
| } |
| |
| |
| /* Determine if OP is valid in SET1 U SET2, which it is when the union |
| contains its value-id. */ |
| |
| static bool |
| op_valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, tree op) |
| { |
| if (op && TREE_CODE (op) == SSA_NAME) |
| { |
| unsigned int value_id = VN_INFO (op)->value_id; |
| if (!(bitmap_set_contains_value (set1, value_id) |
| || (set2 && bitmap_set_contains_value (set2, value_id)))) |
| return false; |
| } |
| return true; |
| } |
| |
| /* Determine if the expression EXPR is valid in SET1 U SET2. |
| ONLY SET2 CAN BE NULL. |
| This means that we have a leader for each part of the expression |
| (if it consists of values), or the expression is an SSA_NAME. |
| For loads/calls, we also see if the vuse is killed in this block. */ |
| |
| static bool |
| valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, pre_expr expr) |
| { |
| switch (expr->kind) |
| { |
| case NAME: |
| /* By construction all NAMEs are available. Non-available |
| NAMEs are removed by subtracting TMP_GEN from the sets. */ |
| return true; |
| case NARY: |
| { |
| unsigned int i; |
| vn_nary_op_t nary = PRE_EXPR_NARY (expr); |
| for (i = 0; i < nary->length; i++) |
| if (!op_valid_in_sets (set1, set2, nary->op[i])) |
| return false; |
| return true; |
| } |
| break; |
| case REFERENCE: |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (expr); |
| vn_reference_op_t vro; |
| unsigned int i; |
| |
| FOR_EACH_VEC_ELT (ref->operands, i, vro) |
| { |
| if (!op_valid_in_sets (set1, set2, vro->op0) |
| || !op_valid_in_sets (set1, set2, vro->op1) |
| || !op_valid_in_sets (set1, set2, vro->op2)) |
| return false; |
| } |
| return true; |
| } |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* Clean the set of expressions SET1 that are no longer valid in SET1 or SET2. |
| This means expressions that are made up of values we have no leaders for |
| in SET1 or SET2. */ |
| |
| static void |
| clean (bitmap_set_t set1, bitmap_set_t set2 = NULL) |
| { |
| vec<pre_expr> exprs = sorted_array_from_bitmap_set (set1); |
| pre_expr expr; |
| int i; |
| |
| FOR_EACH_VEC_ELT (exprs, i, expr) |
| { |
| if (!valid_in_sets (set1, set2, expr)) |
| { |
| unsigned int val = get_expr_value_id (expr); |
| bitmap_clear_bit (&set1->expressions, get_expression_id (expr)); |
| /* We are entered with possibly multiple expressions for a value |
| so before removing a value from the set see if there's an |
| expression for it left. */ |
| if (! bitmap_find_leader (set1, val)) |
| bitmap_clear_bit (&set1->values, val); |
| } |
| } |
| exprs.release (); |
| |
| if (flag_checking) |
| { |
| unsigned j; |
| bitmap_iterator bi; |
| FOR_EACH_EXPR_ID_IN_SET (set1, j, bi) |
| gcc_assert (valid_in_sets (set1, set2, expression_for_id (j))); |
| } |
| } |
| |
| /* Clean the set of expressions that are no longer valid in SET because |
| they are clobbered in BLOCK or because they trap and may not be executed. */ |
| |
| static void |
| prune_clobbered_mems (bitmap_set_t set, basic_block block) |
| { |
| bitmap_iterator bi; |
| unsigned i; |
| unsigned to_remove = -1U; |
| bool any_removed = false; |
| |
| FOR_EACH_EXPR_ID_IN_SET (set, i, bi) |
| { |
| /* Remove queued expr. */ |
| if (to_remove != -1U) |
| { |
| bitmap_clear_bit (&set->expressions, to_remove); |
| any_removed = true; |
| to_remove = -1U; |
| } |
| |
| pre_expr expr = expression_for_id (i); |
| if (expr->kind == REFERENCE) |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (expr); |
| if (ref->vuse) |
| { |
| gimple *def_stmt = SSA_NAME_DEF_STMT (ref->vuse); |
| if (!gimple_nop_p (def_stmt) |
| && ((gimple_bb (def_stmt) != block |
| && !dominated_by_p (CDI_DOMINATORS, |
| block, gimple_bb (def_stmt))) |
| || (gimple_bb (def_stmt) == block |
| && value_dies_in_block_x (expr, block)))) |
| to_remove = i; |
| } |
| } |
| else if (expr->kind == NARY) |
| { |
| vn_nary_op_t nary = PRE_EXPR_NARY (expr); |
| /* If the NARY may trap make sure the block does not contain |
| a possible exit point. |
| ??? This is overly conservative if we translate AVAIL_OUT |
| as the available expression might be after the exit point. */ |
| if (BB_MAY_NOTRETURN (block) |
| && vn_nary_may_trap (nary)) |
| to_remove = i; |
| } |
| } |
| |
| /* Remove queued expr. */ |
| if (to_remove != -1U) |
| { |
| bitmap_clear_bit (&set->expressions, to_remove); |
| any_removed = true; |
| } |
| |
| /* Above we only removed expressions, now clean the set of values |
| which no longer have any corresponding expression. We cannot |
| clear the value at the time we remove an expression since there |
| may be multiple expressions per value. |
| If we'd queue possibly to be removed values we could use |
| the bitmap_find_leader way to see if there's still an expression |
| for it. For some ratio of to be removed values and number of |
| values/expressions in the set this might be faster than rebuilding |
| the value-set. */ |
| if (any_removed) |
| { |
| bitmap_clear (&set->values); |
| FOR_EACH_EXPR_ID_IN_SET (set, i, bi) |
| { |
| pre_expr expr = expression_for_id (i); |
| unsigned int value_id = get_expr_value_id (expr); |
| bitmap_set_bit (&set->values, value_id); |
| } |
| } |
| } |
| |
| /* Compute the ANTIC set for BLOCK. |
| |
| If succs(BLOCK) > 1 then |
| ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK) |
| else if succs(BLOCK) == 1 then |
| ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)]) |
| |
| ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK]) |
| |
| Note that clean() is deferred until after the iteration. */ |
| |
| static bool |
| compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge) |
| { |
| bitmap_set_t S, old, ANTIC_OUT; |
| edge e; |
| edge_iterator ei; |
| |
| bool was_visited = BB_VISITED (block); |
| bool changed = ! BB_VISITED (block); |
| BB_VISITED (block) = 1; |
| old = ANTIC_OUT = S = NULL; |
| |
| /* If any edges from predecessors are abnormal, antic_in is empty, |
| so do nothing. */ |
| if (block_has_abnormal_pred_edge) |
| goto maybe_dump_sets; |
| |
| old = ANTIC_IN (block); |
| ANTIC_OUT = bitmap_set_new (); |
| |
| /* If the block has no successors, ANTIC_OUT is empty. */ |
| if (EDGE_COUNT (block->succs) == 0) |
| ; |
| /* If we have one successor, we could have some phi nodes to |
| translate through. */ |
| else if (single_succ_p (block)) |
| { |
| e = single_succ_edge (block); |
| gcc_assert (BB_VISITED (e->dest)); |
| phi_translate_set (ANTIC_OUT, ANTIC_IN (e->dest), e); |
| } |
| /* If we have multiple successors, we take the intersection of all of |
| them. Note that in the case of loop exit phi nodes, we may have |
| phis to translate through. */ |
| else |
| { |
| size_t i; |
| edge first = NULL; |
| |
| auto_vec<edge> worklist (EDGE_COUNT (block->succs)); |
| FOR_EACH_EDGE (e, ei, block->succs) |
| { |
| if (!first |
| && BB_VISITED (e->dest)) |
| first = e; |
| else if (BB_VISITED (e->dest)) |
| worklist.quick_push (e); |
| else |
| { |
| /* Unvisited successors get their ANTIC_IN replaced by the |
| maximal set to arrive at a maximum ANTIC_IN solution. |
| We can ignore them in the intersection operation and thus |
| need not explicitely represent that maximum solution. */ |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "ANTIC_IN is MAX on %d->%d\n", |
| e->src->index, e->dest->index); |
| } |
| } |
| |
| /* Of multiple successors we have to have visited one already |
| which is guaranteed by iteration order. */ |
| gcc_assert (first != NULL); |
| |
| phi_translate_set (ANTIC_OUT, ANTIC_IN (first->dest), first); |
| |
| /* If we have multiple successors we need to intersect the ANTIC_OUT |
| sets. For values that's a simple intersection but for |
| expressions it is a union. Given we want to have a single |
| expression per value in our sets we have to canonicalize. |
| Avoid randomness and running into cycles like for PR82129 and |
| canonicalize the expression we choose to the one with the |
| lowest id. This requires we actually compute the union first. */ |
| FOR_EACH_VEC_ELT (worklist, i, e) |
| { |
| if (!gimple_seq_empty_p (phi_nodes (e->dest))) |
| { |
| bitmap_set_t tmp = bitmap_set_new (); |
| phi_translate_set (tmp, ANTIC_IN (e->dest), e); |
| bitmap_and_into (&ANTIC_OUT->values, &tmp->values); |
| bitmap_ior_into (&ANTIC_OUT->expressions, &tmp->expressions); |
| bitmap_set_free (tmp); |
| } |
| else |
| { |
| bitmap_and_into (&ANTIC_OUT->values, &ANTIC_IN (e->dest)->values); |
| bitmap_ior_into (&ANTIC_OUT->expressions, |
| &ANTIC_IN (e->dest)->expressions); |
| } |
| } |
| if (! worklist.is_empty ()) |
| { |
| /* Prune expressions not in the value set. */ |
| bitmap_iterator bi; |
| unsigned int i; |
| unsigned int to_clear = -1U; |
| FOR_EACH_EXPR_ID_IN_SET (ANTIC_OUT, i, bi) |
| { |
| if (to_clear != -1U) |
| { |
| bitmap_clear_bit (&ANTIC_OUT->expressions, to_clear); |
| to_clear = -1U; |
| } |
| pre_expr expr = expression_for_id (i); |
| unsigned int value_id = get_expr_value_id (expr); |
| if (!bitmap_bit_p (&ANTIC_OUT->values, value_id)) |
| to_clear = i; |
| } |
| if (to_clear != -1U) |
| bitmap_clear_bit (&ANTIC_OUT->expressions, to_clear); |
| } |
| } |
| |
| /* Prune expressions that are clobbered in block and thus become |
| invalid if translated from ANTIC_OUT to ANTIC_IN. */ |
| prune_clobbered_mems (ANTIC_OUT, block); |
| |
| /* Generate ANTIC_OUT - TMP_GEN. */ |
| S = bitmap_set_subtract_expressions (ANTIC_OUT, TMP_GEN (block)); |
| |
| /* Start ANTIC_IN with EXP_GEN - TMP_GEN. */ |
| ANTIC_IN (block) = bitmap_set_subtract_expressions (EXP_GEN (block), |
| TMP_GEN (block)); |
| |
| /* Then union in the ANTIC_OUT - TMP_GEN values, |
| to get ANTIC_OUT U EXP_GEN - TMP_GEN */ |
| bitmap_ior_into (&ANTIC_IN (block)->values, &S->values); |
| bitmap_ior_into (&ANTIC_IN (block)->expressions, &S->expressions); |
| |
| /* clean (ANTIC_IN (block)) is defered to after the iteration converged |
| because it can cause non-convergence, see for example PR81181. */ |
| |
| /* Intersect ANTIC_IN with the old ANTIC_IN. This is required until |
| we properly represent the maximum expression set, thus not prune |
| values without expressions during the iteration. */ |
| if (was_visited |
| && bitmap_and_into (&ANTIC_IN (block)->values, &old->values)) |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "warning: intersecting with old ANTIC_IN " |
| "shrinks the set\n"); |
| /* Prune expressions not in the value set. */ |
| bitmap_iterator bi; |
| unsigned int i; |
| unsigned int to_clear = -1U; |
| FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (block), i, bi) |
| { |
| if (to_clear != -1U) |
| { |
| bitmap_clear_bit (&ANTIC_IN (block)->expressions, to_clear); |
| to_clear = -1U; |
| } |
| pre_expr expr = expression_for_id (i); |
| unsigned int value_id = get_expr_value_id (expr); |
| if (!bitmap_bit_p (&ANTIC_IN (block)->values, value_id)) |
| to_clear = i; |
| } |
| if (to_clear != -1U) |
| bitmap_clear_bit (&ANTIC_IN (block)->expressions, to_clear); |
| } |
| |
| if (!bitmap_set_equal (old, ANTIC_IN (block))) |
| changed = true; |
| |
| maybe_dump_sets: |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| if (ANTIC_OUT) |
| print_bitmap_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index); |
| |
| if (changed) |
| fprintf (dump_file, "[changed] "); |
| print_bitmap_set (dump_file, ANTIC_IN (block), "ANTIC_IN", |
| block->index); |
| |
| if (S) |
| print_bitmap_set (dump_file, S, "S", block->index); |
| } |
| if (old) |
| bitmap_set_free (old); |
| if (S) |
| bitmap_set_free (S); |
| if (ANTIC_OUT) |
| bitmap_set_free (ANTIC_OUT); |
| return changed; |
| } |
| |
| /* Compute PARTIAL_ANTIC for BLOCK. |
| |
| If succs(BLOCK) > 1 then |
| PA_OUT[BLOCK] = value wise union of PA_IN[b] + all ANTIC_IN not |
| in ANTIC_OUT for all succ(BLOCK) |
| else if succs(BLOCK) == 1 then |
| PA_OUT[BLOCK] = phi_translate (PA_IN[succ(BLOCK)]) |
| |
| PA_IN[BLOCK] = clean(PA_OUT[BLOCK] - TMP_GEN[BLOCK] - ANTIC_IN[BLOCK]) |
| |
| */ |
| static void |
| compute_partial_antic_aux (basic_block block, |
| bool block_has_abnormal_pred_edge) |
| { |
| bitmap_set_t old_PA_IN; |
| bitmap_set_t PA_OUT; |
| edge e; |
| edge_iterator ei; |
| unsigned long max_pa = param_max_partial_antic_length; |
| |
| old_PA_IN = PA_OUT = NULL; |
| |
| /* If any edges from predecessors are abnormal, antic_in is empty, |
| so do nothing. */ |
| if (block_has_abnormal_pred_edge) |
| goto maybe_dump_sets; |
| |
| /* If there are too many partially anticipatable values in the |
| block, phi_translate_set can take an exponential time: stop |
| before the translation starts. */ |
| if (max_pa |
| && single_succ_p (block) |
| && bitmap_count_bits (&PA_IN (single_succ (block))->values) > max_pa) |
| goto maybe_dump_sets; |
| |
| old_PA_IN = PA_IN (block); |
| PA_OUT = bitmap_set_new (); |
| |
| /* If the block has no successors, ANTIC_OUT is empty. */ |
| if (EDGE_COUNT (block->succs) == 0) |
| ; |
| /* If we have one successor, we could have some phi nodes to |
| translate through. Note that we can't phi translate across DFS |
| back edges in partial antic, because it uses a union operation on |
| the successors. For recurrences like IV's, we will end up |
| generating a new value in the set on each go around (i + 3 (VH.1) |
| VH.1 + 1 (VH.2), VH.2 + 1 (VH.3), etc), forever. */ |
| else if (single_succ_p (block)) |
| { |
| e = single_succ_edge (block); |
| if (!(e->flags & EDGE_DFS_BACK)) |
| phi_translate_set (PA_OUT, PA_IN (e->dest), e); |
| } |
| /* If we have multiple successors, we take the union of all of |
| them. */ |
| else |
| { |
| size_t i; |
| |
| auto_vec<edge> worklist (EDGE_COUNT (block->succs)); |
| FOR_EACH_EDGE (e, ei, block->succs) |
| { |
| if (e->flags & EDGE_DFS_BACK) |
| continue; |
| worklist.quick_push (e); |
| } |
| if (worklist.length () > 0) |
| { |
| FOR_EACH_VEC_ELT (worklist, i, e) |
| { |
| unsigned int i; |
| bitmap_iterator bi; |
| |
| FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (e->dest), i, bi) |
| bitmap_value_insert_into_set (PA_OUT, |
| expression_for_id (i)); |
| if (!gimple_seq_empty_p (phi_nodes (e->dest))) |
| { |
| bitmap_set_t pa_in = bitmap_set_new (); |
| phi_translate_set (pa_in, PA_IN (e->dest), e); |
| FOR_EACH_EXPR_ID_IN_SET (pa_in, i, bi) |
| bitmap_value_insert_into_set (PA_OUT, |
| expression_for_id (i)); |
| bitmap_set_free (pa_in); |
| } |
| else |
| FOR_EACH_EXPR_ID_IN_SET (PA_IN (e->dest), i, bi) |
| bitmap_value_insert_into_set (PA_OUT, |
| expression_for_id (i)); |
| } |
| } |
| } |
| |
| /* Prune expressions that are clobbered in block and thus become |
| invalid if translated from PA_OUT to PA_IN. */ |
| prune_clobbered_mems (PA_OUT, block); |
| |
| /* PA_IN starts with PA_OUT - TMP_GEN. |
| Then we subtract things from ANTIC_IN. */ |
| PA_IN (block) = bitmap_set_subtract_expressions (PA_OUT, TMP_GEN (block)); |
| |
| /* For partial antic, we want to put back in the phi results, since |
| we will properly avoid making them partially antic over backedges. */ |
| bitmap_ior_into (&PA_IN (block)->values, &PHI_GEN (block)->values); |
| bitmap_ior_into (&PA_IN (block)->expressions, &PHI_GEN (block)->expressions); |
| |
| /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */ |
| bitmap_set_subtract_values (PA_IN (block), ANTIC_IN (block)); |
| |
| clean (PA_IN (block), ANTIC_IN (block)); |
| |
| maybe_dump_sets: |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| if (PA_OUT) |
| print_bitmap_set (dump_file, PA_OUT, "PA_OUT", block->index); |
| |
| print_bitmap_set (dump_file, PA_IN (block), "PA_IN", block->index); |
| } |
| if (old_PA_IN) |
| bitmap_set_free (old_PA_IN); |
| if (PA_OUT) |
| bitmap_set_free (PA_OUT); |
| } |
| |
| /* Compute ANTIC and partial ANTIC sets. */ |
| |
| static void |
| compute_antic (void) |
| { |
| bool changed = true; |
| int num_iterations = 0; |
| basic_block block; |
| int i; |
| edge_iterator ei; |
| edge e; |
| |
| /* If any predecessor edges are abnormal, we punt, so antic_in is empty. |
| We pre-build the map of blocks with incoming abnormal edges here. */ |
| auto_sbitmap has_abnormal_preds (last_basic_block_for_fn (cfun)); |
| bitmap_clear (has_abnormal_preds); |
| |
| FOR_ALL_BB_FN (block, cfun) |
| { |
| BB_VISITED (block) = 0; |
| |
| FOR_EACH_EDGE (e, ei, block->preds) |
| if (e->flags & EDGE_ABNORMAL) |
| { |
| bitmap_set_bit (has_abnormal_preds, block->index); |
| break; |
| } |
| |
| /* While we are here, give empty ANTIC_IN sets to each block. */ |
| ANTIC_IN (block) = bitmap_set_new (); |
| if (do_partial_partial) |
| PA_IN (block) = bitmap_set_new (); |
| } |
| |
| /* At the exit block we anticipate nothing. */ |
| BB_VISITED (EXIT_BLOCK_PTR_FOR_FN (cfun)) = 1; |
| |
| /* For ANTIC computation we need a postorder that also guarantees that |
| a block with a single successor is visited after its successor. |
| RPO on the inverted CFG has this property. */ |
| auto_vec<int, 20> postorder; |
| inverted_post_order_compute (&postorder); |
| |
| auto_sbitmap worklist (last_basic_block_for_fn (cfun) + 1); |
| bitmap_clear (worklist); |
| FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds) |
| bitmap_set_bit (worklist, e->src->index); |
| while (changed) |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "Starting iteration %d\n", num_iterations); |
| /* ??? We need to clear our PHI translation cache here as the |
| ANTIC sets shrink and we restrict valid translations to |
| those having operands with leaders in ANTIC. Same below |
| for PA ANTIC computation. */ |
| num_iterations++; |
| changed = false; |
| for (i = postorder.length () - 1; i >= 0; i--) |
| { |
| if (bitmap_bit_p (worklist, postorder[i])) |
| { |
| basic_block block = BASIC_BLOCK_FOR_FN (cfun, postorder[i]); |
| bitmap_clear_bit (worklist, block->index); |
| if (compute_antic_aux (block, |
| bitmap_bit_p (has_abnormal_preds, |
| block->index))) |
| { |
| FOR_EACH_EDGE (e, ei, block->preds) |
| bitmap_set_bit (worklist, e->src->index); |
| changed = true; |
| } |
| } |
| } |
| /* Theoretically possible, but *highly* unlikely. */ |
| gcc_checking_assert (num_iterations < 500); |
| } |
| |
| /* We have to clean after the dataflow problem converged as cleaning |
| can cause non-convergence because it is based on expressions |
| rather than values. */ |
| FOR_EACH_BB_FN (block, cfun) |
| clean (ANTIC_IN (block)); |
| |
| statistics_histogram_event (cfun, "compute_antic iterations", |
| num_iterations); |
| |
| if (do_partial_partial) |
| { |
| /* For partial antic we ignore backedges and thus we do not need |
| to perform any iteration when we process blocks in postorder. */ |
| for (i = postorder.length () - 1; i >= 0; i--) |
| { |
| basic_block block = BASIC_BLOCK_FOR_FN (cfun, postorder[i]); |
| compute_partial_antic_aux (block, |
| bitmap_bit_p (has_abnormal_preds, |
| block->index)); |
| } |
| } |
| } |
| |
| |
| /* Inserted expressions are placed onto this worklist, which is used |
| for performing quick dead code elimination of insertions we made |
| that didn't turn out to be necessary. */ |
| static bitmap inserted_exprs; |
| |
| /* The actual worker for create_component_ref_by_pieces. */ |
| |
| static tree |
| create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref, |
| unsigned int *operand, gimple_seq *stmts) |
| { |
| vn_reference_op_t currop = &ref->operands[*operand]; |
| tree genop; |
| ++*operand; |
| switch (currop->opcode) |
| { |
| case CALL_EXPR: |
| gcc_unreachable (); |
| |
| case MEM_REF: |
| { |
| tree baseop = create_component_ref_by_pieces_1 (block, ref, operand, |
| stmts); |
| if (!baseop) |
| return NULL_TREE; |
| tree offset = currop->op0; |
| if (TREE_CODE (baseop) == ADDR_EXPR |
| && handled_component_p (TREE_OPERAND (baseop, 0))) |
| { |
| poly_int64 off; |
| tree base; |
| base = get_addr_base_and_unit_offset (TREE_OPERAND (baseop, 0), |
| &off); |
| gcc_assert (base); |
| offset = int_const_binop (PLUS_EXPR, offset, |
| build_int_cst (TREE_TYPE (offset), |
| off)); |
| baseop = build_fold_addr_expr (base); |
| } |
| genop = build2 (MEM_REF, currop->type, baseop, offset); |
| MR_DEPENDENCE_CLIQUE (genop) = currop->clique; |
| MR_DEPENDENCE_BASE (genop) = currop->base; |
| REF_REVERSE_STORAGE_ORDER (genop) = currop->reverse; |
| return genop; |
| } |
| |
| case TARGET_MEM_REF: |
| { |
| tree genop0 = NULL_TREE, genop1 = NULL_TREE; |
| vn_reference_op_t nextop = &ref->operands[(*operand)++]; |
| tree baseop = create_component_ref_by_pieces_1 (block, ref, operand, |
| stmts); |
| if (!baseop) |
| return NULL_TREE; |
| if (currop->op0) |
| { |
| genop0 = find_or_generate_expression (block, currop->op0, stmts); |
| if (!genop0) |
| return NULL_TREE; |
| } |
| if (nextop->op0) |
| { |
| genop1 = find_or_generate_expression (block, nextop->op0, stmts); |
| if (!genop1) |
| return NULL_TREE; |
| } |
| genop = build5 (TARGET_MEM_REF, currop->type, |
| baseop, currop->op2, genop0, currop->op1, genop1); |
| |
| MR_DEPENDENCE_CLIQUE (genop) = currop->clique; |
| MR_DEPENDENCE_BASE (genop) = currop->base; |
| return genop; |
| } |
| |
| case ADDR_EXPR: |
| if (currop->op0) |
| { |
| gcc_assert (is_gimple_min_invariant (currop->op0)); |
| return currop->op0; |
| } |
| /* Fallthrough. */ |
| case REALPART_EXPR: |
| case IMAGPART_EXPR: |
| case VIEW_CONVERT_EXPR: |
| { |
| tree genop0 = create_component_ref_by_pieces_1 (block, ref, operand, |
| stmts); |
| if (!genop0) |
| return NULL_TREE; |
| return fold_build1 (currop->opcode, currop->type, genop0); |
| } |
| |
| case WITH_SIZE_EXPR: |
| { |
| tree genop0 = create_component_ref_by_pieces_1 (block, ref, operand, |
| stmts); |
| if (!genop0) |
| return NULL_TREE; |
| tree genop1 = find_or_generate_expression (block, currop->op0, stmts); |
| if (!genop1) |
| return NULL_TREE; |
| return fold_build2 (currop->opcode, currop->type, genop0, genop1); |
| } |
| |
| case BIT_FIELD_REF: |
| { |
| tree genop0 = create_component_ref_by_pieces_1 (block, ref, operand, |
| stmts); |
| if (!genop0) |
| return NULL_TREE; |
| tree op1 = currop->op0; |
| tree op2 = currop->op1; |
| tree t = build3 (BIT_FIELD_REF, currop->type, genop0, op1, op2); |
| REF_REVERSE_STORAGE_ORDER (t) = currop->reverse; |
| return fold (t); |
| } |
| |
| /* For array ref vn_reference_op's, operand 1 of the array ref |
| is op0 of the reference op and operand 3 of the array ref is |
| op1. */ |
| case ARRAY_RANGE_REF: |
| case ARRAY_REF: |
| { |
| tree genop0; |
| tree genop1 = currop->op0; |
| tree genop2 = currop->op1; |
| tree genop3 = currop->op2; |
| genop0 = create_component_ref_by_pieces_1 (block, ref, operand, |
| stmts); |
| if (!genop0) |
| return NULL_TREE; |
| genop1 = find_or_generate_expression (block, genop1, stmts); |
| if (!genop1) |
| return NULL_TREE; |
| if (genop2) |
| { |
| tree domain_type = TYPE_DOMAIN (TREE_TYPE (genop0)); |
| /* Drop zero minimum index if redundant. */ |
| if (integer_zerop (genop2) |
| && (!domain_type |
| || integer_zerop (TYPE_MIN_VALUE (domain_type)))) |
| genop2 = NULL_TREE; |
| else |
| { |
| genop2 = find_or_generate_expression (block, genop2, stmts); |
| if (!genop2) |
| return NULL_TREE; |
| } |
| } |
| if (genop3) |
| { |
| tree elmt_type = TREE_TYPE (TREE_TYPE (genop0)); |
| /* We can't always put a size in units of the element alignment |
| here as the element alignment may be not visible. See |
| PR43783. Simply drop the element size for constant |
| sizes. */ |
| if (TREE_CODE (genop3) == INTEGER_CST |
| && TREE_CODE (TYPE_SIZE_UNIT (elmt_type)) == INTEGER_CST |
| && wi::eq_p (wi::to_offset (TYPE_SIZE_UNIT (elmt_type)), |
| (wi::to_offset (genop3) |
| * vn_ref_op_align_unit (currop)))) |
| genop3 = NULL_TREE; |
| else |
| { |
| genop3 = find_or_generate_expression (block, genop3, stmts); |
| if (!genop3) |
| return NULL_TREE; |
| } |
| } |
| return build4 (currop->opcode, currop->type, genop0, genop1, |
| genop2, genop3); |
| } |
| case COMPONENT_REF: |
| { |
| tree op0; |
| tree op1; |
| tree genop2 = currop->op1; |
| op0 = create_component_ref_by_pieces_1 (block, ref, operand, stmts); |
| if (!op0) |
| return NULL_TREE; |
| /* op1 should be a FIELD_DECL, which are represented by themselves. */ |
| op1 = currop->op0; |
| if (genop2) |
| { |
| genop2 = find_or_generate_expression (block, genop2, stmts); |
| if (!genop2) |
| return NULL_TREE; |
| } |
| return fold_build3 (COMPONENT_REF, TREE_TYPE (op1), op0, op1, genop2); |
| } |
| |
| case SSA_NAME: |
| { |
| genop = find_or_generate_expression (block, currop->op0, stmts); |
| return genop; |
| } |
| case STRING_CST: |
| case INTEGER_CST: |
| case POLY_INT_CST: |
| case COMPLEX_CST: |
| case VECTOR_CST: |
| case REAL_CST: |
| case CONSTRUCTOR: |
| case VAR_DECL: |
| case PARM_DECL: |
| case CONST_DECL: |
| case RESULT_DECL: |
| case FUNCTION_DECL: |
| return currop->op0; |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the |
| COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with |
| trying to rename aggregates into ssa form directly, which is a no no. |
| |
| Thus, this routine doesn't create temporaries, it just builds a |
| single access expression for the array, calling |
| find_or_generate_expression to build the innermost pieces. |
| |
| This function is a subroutine of create_expression_by_pieces, and |
| should not be called on it's own unless you really know what you |
| are doing. */ |
| |
| static tree |
| create_component_ref_by_pieces (basic_block block, vn_reference_t ref, |
| gimple_seq *stmts) |
| { |
| unsigned int op = 0; |
| return create_component_ref_by_pieces_1 (block, ref, &op, stmts); |
| } |
| |
| /* Find a simple leader for an expression, or generate one using |
| create_expression_by_pieces from a NARY expression for the value. |
| BLOCK is the basic_block we are looking for leaders in. |
| OP is the tree expression to find a leader for or generate. |
| Returns the leader or NULL_TREE on failure. */ |
| |
| static tree |
| find_or_generate_expression (basic_block block, tree op, gimple_seq *stmts) |
| { |
| pre_expr expr = get_or_alloc_expr_for (op); |
| unsigned int lookfor = get_expr_value_id (expr); |
| pre_expr leader = bitmap_find_leader (AVAIL_OUT (block), lookfor); |
| if (leader) |
| { |
| if (leader->kind == NAME) |
| return PRE_EXPR_NAME (leader); |
| else if (leader->kind == CONSTANT) |
| return PRE_EXPR_CONSTANT (leader); |
| |
| /* Defer. */ |
| return NULL_TREE; |
| } |
| |
| /* It must be a complex expression, so generate it recursively. Note |
| that this is only necessary to handle gcc.dg/tree-ssa/ssa-pre28.c |
| where the insert algorithm fails to insert a required expression. */ |
| bitmap exprset = value_expressions[lookfor]; |
| bitmap_iterator bi; |
| unsigned int i; |
| EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi) |
| { |
| pre_expr temp = expression_for_id (i); |
| /* We cannot insert random REFERENCE expressions at arbitrary |
| places. We can insert NARYs which eventually re-materializes |
| its operand values. */ |
| if (temp->kind == NARY) |
| return create_expression_by_pieces (block, temp, stmts, |
| get_expr_type (expr)); |
| } |
| |
| /* Defer. */ |
| return NULL_TREE; |
| } |
| |
| /* Create an expression in pieces, so that we can handle very complex |
| expressions that may be ANTIC, but not necessary GIMPLE. |
| BLOCK is the basic block the expression will be inserted into, |
| EXPR is the expression to insert (in value form) |
| STMTS is a statement list to append the necessary insertions into. |
| |
| This function will die if we hit some value that shouldn't be |
| ANTIC but is (IE there is no leader for it, or its components). |
| The function returns NULL_TREE in case a different antic expression |
| has to be inserted first. |
| This function may also generate expressions that are themselves |
| partially or fully redundant. Those that are will be either made |
| fully redundant during the next iteration of insert (for partially |
| redundant ones), or eliminated by eliminate (for fully redundant |
| ones). */ |
| |
| static tree |
| create_expression_by_pieces (basic_block block, pre_expr expr, |
| gimple_seq *stmts, tree type) |
| { |
| tree name; |
| tree folded; |
| gimple_seq forced_stmts = NULL; |
| unsigned int value_id; |
| gimple_stmt_iterator gsi; |
| tree exprtype = type ? type : get_expr_type (expr); |
| pre_expr nameexpr; |
| gassign *newstmt; |
| |
| switch (expr->kind) |
| { |
| /* We may hit the NAME/CONSTANT case if we have to convert types |
| that value numbering saw through. */ |
| case NAME: |
| folded = PRE_EXPR_NAME (expr); |
| if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (folded)) |
| return NULL_TREE; |
| if (useless_type_conversion_p (exprtype, TREE_TYPE (folded))) |
| return folded; |
| break; |
| case CONSTANT: |
| { |
| folded = PRE_EXPR_CONSTANT (expr); |
| tree tem = fold_convert (exprtype, folded); |
| if (is_gimple_min_invariant (tem)) |
| return tem; |
| break; |
| } |
| case REFERENCE: |
| if (PRE_EXPR_REFERENCE (expr)->operands[0].opcode == CALL_EXPR) |
| { |
| vn_reference_t ref = PRE_EXPR_REFERENCE (expr); |
| unsigned int operand = 1; |
| vn_reference_op_t currop = &ref->operands[0]; |
| tree sc = NULL_TREE; |
| tree fn = find_or_generate_expression (block, currop->op0, stmts); |
| if (!fn) |
| return NULL_TREE; |
| if (currop->op1) |
| { |
| sc = find_or_generate_expression (block, currop->op1, stmts); |
| if (!sc) |
| return NULL_TREE; |
| } |
| auto_vec<tree> args (ref->operands.length () - 1); |
| while (operand < ref->operands.length ()) |
| { |
| tree arg = create_component_ref_by_pieces_1 (block, ref, |
| &operand, stmts); |
| if (!arg) |
| return NULL_TREE; |
| args.quick_push (arg); |
| } |
| gcall *call = gimple_build_call_vec (fn, args); |
| gimple_set_location (call, expr->loc); |
| gimple_call_set_fntype (call, currop->type); |
| if (sc) |
| gimple_call_set_chain (call, sc); |
| tree forcedname = make_ssa_name (TREE_TYPE (currop->type)); |
| gimple_call_set_lhs (call, forcedname); |
| /* There's no CCP pass after PRE which would re-compute alignment |
| information so make sure we re-materialize this here. */ |
| if (gimple_call_builtin_p (call, BUILT_IN_ASSUME_ALIGNED) |
| && args.length () - 2 <= 1 |
| && tree_fits_uhwi_p (args[1]) |
| && (args.length () != 3 || tree_fits_uhwi_p (args[2]))) |
| { |
| unsigned HOST_WIDE_INT halign = tree_to_uhwi (args[1]); |
| unsigned HOST_WIDE_INT hmisalign |
| = args.length () == 3 ? tree_to_uhwi (args[2]) : 0; |
| if ((halign & (halign - 1)) == 0 |
| && (hmisalign & ~(halign - 1)) == 0 |
| && (unsigned int)halign != 0) |
| set_ptr_info_alignment (get_ptr_info (forcedname), |
| halign, hmisalign); |
| } |
| gimple_set_vuse (call, BB_LIVE_VOP_ON_EXIT (block)); |
| gimple_seq_add_stmt_without_update (&forced_stmts, call); |
| folded = forcedname; |
| } |
| else |
| { |
| folded = create_component_ref_by_pieces (block, |
| PRE_EXPR_REFERENCE (expr), |
| stmts); |
| if (!folded) |
| return NULL_TREE; |
| name = make_temp_ssa_name (exprtype, NULL, "pretmp"); |
| newstmt = gimple_build_assign (name, folded); |
| gimple_set_location (newstmt, expr->loc); |
| gimple_seq_add_stmt_without_update (&forced_stmts, newstmt); |
| gimple_set_vuse (newstmt, BB_LIVE_VOP_ON_EXIT (block)); |
| folded = name; |
| } |
| break; |
| case NARY: |
| { |
| vn_nary_op_t nary = PRE_EXPR_NARY (expr); |
| tree *genop = XALLOCAVEC (tree, nary->length); |
| unsigned i; |
| for (i = 0; i < nary->length; ++i) |
| { |
| genop[i] = find_or_generate_expression (block, nary->op[i], stmts); |
| if (!genop[i]) |
| return NULL_TREE; |
| /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR. It |
| may have conversions stripped. */ |
| if (nary->opcode == POINTER_PLUS_EXPR) |
| { |
| if (i == 0) |
| genop[i] = gimple_convert (&forced_stmts, |
| nary->type, genop[i]); |
| else if (i == 1) |
| genop[i] = gimple_convert (&forced_stmts, |
| sizetype, genop[i]); |
| } |
| else |
| genop[i] = gimple_convert (&forced_stmts, |
| TREE_TYPE (nary->op[i]), genop[i]); |
| } |
| if (nary->opcode == CONSTRUCTOR) |
| { |
| vec<constructor_elt, va_gc> *elts = NULL; |
| for (i = 0; i < nary->length; ++i) |
| CONSTRUCTOR_APPEND_ELT (elts, NULL_TREE, genop[i]); |
| folded = build_constructor (nary->type, elts); |
| name = make_temp_ssa_name (exprtype, NULL, "pretmp"); |
| newstmt = gimple_build_assign (name, folded); |
| gimple_set_location (newstmt, expr->loc); |
| gimple_seq_add_stmt_without_update (&forced_stmts, newstmt); |
| folded = name; |
| } |
| else |
| { |
| switch (nary->length) |
| { |
| case 1: |
| folded = gimple_build (&forced_stmts, expr->loc, |
| nary->opcode, nary->type, genop[0]); |
| break; |
| case 2: |
| folded = gimple_build (&forced_stmts, expr->loc, nary->opcode, |
| nary->type, genop[0], genop[1]); |
| break; |
| case 3: |
| folded = gimple_build (&forced_stmts, expr->loc, nary->opcode, |
| nary->type, genop[0], genop[1], |
| genop[2]); |
| break; |
| default: |
| gcc_unreachable (); |
| } |
| } |
| } |
| break; |
| default: |
| gcc_unreachable (); |
| } |
| |
| folded = gimple_convert (&forced_stmts, exprtype, folded); |
| |
| /* If there is nothing to insert, return the simplified result. */ |
| if (gimple_seq_empty_p (forced_stmts)) |
| return folded; |
| /* If we simplified to a constant return it and discard eventually |
| built stmts. */ |
| if (is_gimple_min_invariant (folded)) |
| { |
| gimple_seq_discard (forced_stmts); |
| return folded; |
| } |
| /* Likewise if we simplified to sth not queued for insertion. */ |
| bool found = false; |
| gsi = gsi_last (forced_stmts); |
| for (; !gsi_end_p (gsi); gsi_prev (&gsi)) |
| { |
| gimple *stmt = gsi_stmt (gsi); |
| tree forcedname = gimple_get_lhs (stmt); |
| if (forcedname == folded) |
| { |
| found = true; |
| break; |
| } |
| } |
| if (! found) |
| { |
| gimple_seq_discard (forced_stmts); |
| return folded; |
| } |
| gcc_assert (TREE_CODE (folded) == SSA_NAME); |
| |
| /* If we have any intermediate expressions to the value sets, add them |
| to the value sets and chain them in the instruction stream. */ |
| if (forced_stmts) |
| { |
| gsi = gsi_start (forced_stmts); |
| for (; !gsi_end_p (gsi); gsi_next (&gsi)) |
| { |
| gimple *stmt = gsi_stmt (gsi); |
| tree forcedname = gimple_get_lhs (stmt); |
| pre_expr nameexpr; |
| |
| if (forcedname != folded) |
| { |
| vn_ssa_aux_t vn_info = VN_INFO (forcedname); |
| vn_info->valnum = forcedname; |
| vn_info->value_id = get_next_value_id (); |
| nameexpr = get_or_alloc_expr_for_name (forcedname); |
| add_to_value (vn_info->value_id, nameexpr); |
| if (NEW_SETS (block)) |
| bitmap_value_replace_in_set (NEW_SETS (block), nameexpr); |
| bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr); |
| } |
| |
| bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (forcedname)); |
| } |
| gimple_seq_add_seq (stmts, forced_stmts); |
| } |
| |
| name = folded; |
| |
| /* Fold the last statement. */ |
| gsi = gsi_last (*stmts); |
| if (fold_stmt_inplace (&gsi)) |
| update_stmt (gsi_stmt (gsi)); |
| |
| /* Add a value number to the temporary. |
| The value may already exist in either NEW_SETS, or AVAIL_OUT, because |
| we are creating the expression by pieces, and this particular piece of |
| the expression may have been represented. There is no harm in replacing |
| here. */ |
| value_id = get_expr_value_id (expr); |
| vn_ssa_aux_t vn_info = VN_INFO (name); |
| vn_info->value_id = value_id; |
| vn_info->valnum = vn_valnum_from_value_id (value_id); |
| if (vn_info->valnum == NULL_TREE) |
| vn_info->valnum = name; |
| gcc_assert (vn_info->valnum != NULL_TREE); |
| nameexpr = get_or_alloc_expr_for_name (name); |
| add_to_value (value_id, nameexpr); |
| if (NEW_SETS (block)) |
| bitmap_value_replace_in_set (NEW_SETS (block), nameexpr); |
| bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr); |
| |
| pre_stats.insertions++; |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Inserted "); |
| print_gimple_stmt (dump_file, gsi_stmt (gsi_last (*stmts)), 0); |
| fprintf (dump_file, " in predecessor %d (%04d)\n", |
| block->index, value_id); |
| } |
| |
| return name; |
| } |
| |
| |
| /* Insert the to-be-made-available values of expression EXPRNUM for each |
| predecessor, stored in AVAIL, into the predecessors of BLOCK, and |
| merge the result with a phi node, given the same value number as |
| NODE. Return true if we have inserted new stuff. */ |
| |
| static bool |
| insert_into_preds_of_block (basic_block block, unsigned int exprnum, |
| vec<pre_expr> avail) |
| { |
| pre_expr expr = expression_for_id (exprnum); |
| pre_expr newphi; |
| unsigned int val = get_expr_value_id (expr); |
| edge pred; |
| bool insertions = false; |
| bool nophi = false; |
| basic_block bprime; |
| pre_expr eprime; |
| edge_iterator ei; |
| tree type = get_expr_type (expr); |
| tree temp; |
| gphi *phi; |
| |
| /* Make sure we aren't creating an induction variable. */ |
| if (bb_loop_depth (block) > 0 && EDGE_COUNT (block->preds) == 2) |
| { |
| bool firstinsideloop = false; |
| bool secondinsideloop = false; |
| firstinsideloop = flow_bb_inside_loop_p (block->loop_father, |
| EDGE_PRED (block, 0)->src); |
| secondinsideloop = flow_bb_inside_loop_p (block->loop_father, |
| EDGE_PRED (block, 1)->src); |
| /* Induction variables only have one edge inside the loop. */ |
| if ((firstinsideloop ^ secondinsideloop) |
| && expr->kind != REFERENCE) |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| fprintf (dump_file, "Skipping insertion of phi for partial " |
| "redundancy: Looks like an induction variable\n"); |
| nophi = true; |
| } |
| } |
| |
| /* Make the necessary insertions. */ |
| FOR_EACH_EDGE (pred, ei, block->preds) |
| { |
| /* When we are not inserting a PHI node do not bother inserting |
| into places that do not dominate the anticipated computations. */ |
| if (nophi && !dominated_by_p (CDI_DOMINATORS, block, pred->src)) |
| continue; |
| gimple_seq stmts = NULL; |
| tree builtexpr; |
| bprime = pred->src; |
| eprime = avail[pred->dest_idx]; |
| builtexpr = create_expression_by_pieces (bprime, eprime, |
| &stmts, type); |
| gcc_assert (!(pred->flags & EDGE_ABNORMAL)); |
| if (!gimple_seq_empty_p (stmts)) |
| { |
| basic_block new_bb = gsi_insert_seq_on_edge_immediate (pred, stmts); |
| gcc_assert (! new_bb); |
| insertions = true; |
| } |
| if (!builtexpr) |
| { |
| /* We cannot insert a PHI node if we failed to insert |
| on one edge. */ |
| nophi = true; |
| continue; |
| } |
| if (is_gimple_min_invariant (builtexpr)) |
| avail[pred->dest_idx] = get_or_alloc_expr_for_constant (builtexpr); |
| else |
| avail[pred->dest_idx] = get_or_alloc_expr_for_name (builtexpr); |
| } |
| /* If we didn't want a phi node, and we made insertions, we still have |
| inserted new stuff, and thus return true. If we didn't want a phi node, |
| and didn't make insertions, we haven't added anything new, so return |
| false. */ |
| if (nophi && insertions) |
| return true; |
| else if (nophi && !insertions) |
| return false; |
| |
| /* Now build a phi for the new variable. */ |
| temp = make_temp_ssa_name (type, NULL, "prephitmp"); |
| phi = create_phi_node (temp, block); |
| |
| vn_ssa_aux_t vn_info = VN_INFO (temp); |
| vn_info->value_id = val; |
| vn_info->valnum = vn_valnum_from_value_id (val); |
| if (vn_info->valnum == NULL_TREE) |
| vn_info->valnum = temp; |
| bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (temp)); |
| FOR_EACH_EDGE (pred, ei, block->preds) |
| { |
| pre_expr ae = avail[pred->dest_idx]; |
| gcc_assert (get_expr_type (ae) == type |
| || useless_type_conversion_p (type, get_expr_type (ae))); |
| if (ae->kind == CONSTANT) |
| add_phi_arg (phi, unshare_expr (PRE_EXPR_CONSTANT (ae)), |
| pred, UNKNOWN_LOCATION); |
| else |
| add_phi_arg (phi, PRE_EXPR_NAME (ae), pred, UNKNOWN_LOCATION); |
| } |
| |
| newphi = get_or_alloc_expr_for_name (temp); |
| add_to_value (val, newphi); |
| |
| /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing |
| this insertion, since we test for the existence of this value in PHI_GEN |
| before proceeding with the partial redundancy checks in insert_aux. |
| |
| The value may exist in AVAIL_OUT, in particular, it could be represented |
| by the expression we are trying to eliminate, in which case we want the |
| replacement to occur. If it's not existing in AVAIL_OUT, we want
|