/* Struct-reorg optimization. Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc. Contributed by Olga Golovanevsky (Initial version of this code was developed by Caroline Tice and Mostafa Hagog.) 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 . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "ggc.h" #include "tree.h" #include "rtl.h" #include "gimple.h" #include "tree-inline.h" #include "tree-flow.h" #include "tree-flow-inline.h" #include "langhooks.h" #include "pointer-set.h" #include "hashtab.h" #include "c-tree.h" #include "toplev.h" #include "flags.h" #include "debug.h" #include "target.h" #include "cgraph.h" #include "diagnostic.h" #include "timevar.h" #include "params.h" #include "fibheap.h" #include "intl.h" #include "function.h" #include "basic-block.h" #include "tree-iterator.h" #include "tree-pass.h" #include "ipa-struct-reorg.h" #include "opts.h" #include "ipa-type-escape.h" #include "tree-dump.h" #include "c-common.h" #include "gimple.h" /* This optimization implements structure peeling. For example, given a structure type: typedef struct { int a; float b; int c; }str_t; it can be peeled into two structure types as follows: typedef struct and typedef struct { { int a; float b; int c; } str_t_1; }str_t_0; or can be fully peeled: typedef struct { int a; }str_t_0; typedef struct { float b; }str_t_1; typedef struct { int c; }str_t_2; When structure type is peeled all instances and their accesses in the program are updated accordingly. For example, if there is array of structures: str_t A[N]; and structure type str_t was peeled into two structures str_t_0 and str_t_1 as it was shown above, then array A will be replaced by two arrays as follows: str_t_0 A_0[N]; str_t_1 A_1[N]; The field access of field a of element i of array A: A[i].a will be replaced by an access to field a of element i of array A_0: A_0[i].a. This optimization also supports dynamically allocated arrays. If array of structures was allocated by malloc function: str_t * p = (str_t *) malloc (sizeof (str_t) * N) the allocation site will be replaced to reflect new structure types: str_t_0 * p_0 = (str_t_0 *) malloc (sizeof (str_t_0) * N) str_t_1 * p_1 = (str_t_1 *) malloc (sizeof (str_t_1) * N) The field access through the pointer p[i].a will be changed by p_0[i].a. The goal of structure peeling is to improve spatial locality. For example, if one of the fields of a structure is accessed frequently in the loop: for (i = 0; i < N; i++) { ... = A[i].a; } the allocation of field a of str_t contiguously in memory will increase the chances of fetching the field from cache. The analysis part of this optimization is based on the frequency of field accesses, which are collected all over the program. Then the fields with the frequencies that satisfy the following condition get peeled out of the structure: freq(f) > C * max_field_freq_in_struct where max_field_freq_in_struct is the maximum field frequency in the structure. C is a constant defining which portion of max_field_freq_in_struct the fields should have in order to be peeled. If profiling information is provided, it is used to calculate the frequency of field accesses. Otherwise, the structure is fully peeled. IPA type-escape analysis is used to determine when it is safe to peel a structure. The optimization is activated by flag -fipa-struct-reorg. */ /* New variables created by this optimization. When doing struct peeling, each variable of the original struct type will be replaced by the set of new variables corresponding to the new structure types. */ struct new_var_data { /* VAR_DECL for original struct type. */ tree orig_var; /* Vector of new variables. */ VEC(tree, heap) *new_vars; }; typedef struct new_var_data *new_var; typedef const struct new_var_data *const_new_var; /* This structure represents allocation site of the structure. */ typedef struct alloc_site { gimple stmt; d_str str; } alloc_site_t; DEF_VEC_O (alloc_site_t); DEF_VEC_ALLOC_O (alloc_site_t, heap); /* Allocation sites that belong to the same function. */ struct func_alloc_sites { tree func; /* Vector of allocation sites for function. */ VEC (alloc_site_t, heap) *allocs; }; typedef struct func_alloc_sites *fallocs_t; typedef const struct func_alloc_sites *const_fallocs_t; /* All allocation sites in the program. */ htab_t alloc_sites = NULL; /* New global variables. Generated once for whole program. */ htab_t new_global_vars; /* New local variables. Generated per-function. */ htab_t new_local_vars; /* Vector of structures to be transformed. */ typedef struct data_structure structure; DEF_VEC_O (structure); DEF_VEC_ALLOC_O (structure, heap); VEC (structure, heap) *structures; /* Forward declarations. */ static bool is_equal_types (tree, tree); /* Strip structure TYPE from pointers and arrays. */ static inline tree strip_type (tree type) { gcc_assert (TYPE_P (type)); while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE) type = TREE_TYPE (type); return type; } /* This function returns type of VAR. */ static inline tree get_type_of_var (tree var) { if (!var) return NULL; if (TREE_CODE (var) == PARM_DECL) return DECL_ARG_TYPE (var); else return TREE_TYPE (var); } /* Set of actions we do for each newly generated STMT. */ static inline void finalize_stmt (gimple stmt) { update_stmt (stmt); mark_symbols_for_renaming (stmt); } /* This function finalizes STMT and appends it to the list STMTS. */ static inline void finalize_stmt_and_append (gimple_seq *stmts, gimple stmt) { gimple_seq_add_stmt (stmts, stmt); finalize_stmt (stmt); } /* Given structure type SRT_TYPE and field FIELD, this function is looking for a field with the same name and type as FIELD in STR_TYPE. It returns it if found, or NULL_TREE otherwise. */ static tree find_field_in_struct_1 (tree str_type, tree field) { tree str_field; for (str_field = TYPE_FIELDS (str_type); str_field; str_field = TREE_CHAIN (str_field)) { const char * str_field_name; const char * field_name; str_field_name = IDENTIFIER_POINTER (DECL_NAME (str_field)); field_name = IDENTIFIER_POINTER (DECL_NAME (field)); gcc_assert (str_field_name); gcc_assert (field_name); if (!strcmp (str_field_name, field_name)) { /* Check field types. */ if (is_equal_types (TREE_TYPE (str_field), TREE_TYPE (field))) return str_field; } } return NULL_TREE; } /* Given a field declaration FIELD_DECL, this function returns corresponding field entry in structure STR. */ static struct field_entry * find_field_in_struct (d_str str, tree field_decl) { int i; tree field = find_field_in_struct_1 (str->decl, field_decl); for (i = 0; i < str->num_fields; i++) if (str->fields[i].decl == field) return &(str->fields[i]); return NULL; } /* This function checks whether ARG is a result of multiplication of some number by STRUCT_SIZE. If yes, the function returns true and this number is filled into NUM. */ static bool is_result_of_mult (tree arg, tree *num, tree struct_size) { gimple size_def_stmt = SSA_NAME_DEF_STMT (arg); /* If the allocation statement was of the form D.2229_10 = (D.2228_9); then size_def_stmt can be D.2228_9 = num.3_8 * 8; */ if (size_def_stmt && is_gimple_assign (size_def_stmt)) { tree lhs = gimple_assign_lhs (size_def_stmt); /* We expect temporary here. */ if (!is_gimple_reg (lhs)) return false; if (gimple_assign_rhs_code (size_def_stmt) == MULT_EXPR) { tree arg0 = gimple_assign_rhs1 (size_def_stmt); tree arg1 = gimple_assign_rhs2 (size_def_stmt); if (operand_equal_p (arg0, struct_size, OEP_ONLY_CONST)) { *num = arg1; return true; } if (operand_equal_p (arg1, struct_size, OEP_ONLY_CONST)) { *num = arg0; return true; } } } *num = NULL_TREE; return false; } /* This function returns true if access ACC corresponds to the pattern generated by compiler when an address of element i of an array of structures STR_DECL (pointed by p) is calculated (p[i]). If this pattern is recognized correctly, this function returns true and fills missing fields in ACC. Otherwise it returns false. */ static bool decompose_indirect_ref_acc (tree str_decl, struct field_access_site *acc) { tree ref_var; tree struct_size, op0, op1; tree before_cast; enum tree_code rhs_code; ref_var = TREE_OPERAND (acc->ref, 0); if (TREE_CODE (ref_var) != SSA_NAME) return false; acc->ref_def_stmt = SSA_NAME_DEF_STMT (ref_var); if (!(acc->ref_def_stmt) || (gimple_code (acc->ref_def_stmt) != GIMPLE_ASSIGN)) return false; rhs_code = gimple_assign_rhs_code (acc->ref_def_stmt); if (rhs_code != PLUS_EXPR && rhs_code != MINUS_EXPR && rhs_code != POINTER_PLUS_EXPR) return false; op0 = gimple_assign_rhs1 (acc->ref_def_stmt); op1 = gimple_assign_rhs2 (acc->ref_def_stmt); if (!is_array_access_through_pointer_and_index (rhs_code, op0, op1, &acc->base, &acc->offset, &acc->cast_stmt)) return false; if (acc->cast_stmt) before_cast = SINGLE_SSA_TREE_OPERAND (acc->cast_stmt, SSA_OP_USE); else before_cast = acc->offset; if (!before_cast) return false; if (SSA_NAME_IS_DEFAULT_DEF (before_cast)) return false; struct_size = TYPE_SIZE_UNIT (str_decl); if (!is_result_of_mult (before_cast, &acc->num, struct_size)) return false; return true; } /* This function checks whether the access ACC of structure type STR is of the form suitable for transformation. If yes, it returns true. False otherwise. */ static bool decompose_access (tree str_decl, struct field_access_site *acc) { gcc_assert (acc->ref); if (TREE_CODE (acc->ref) == INDIRECT_REF) return decompose_indirect_ref_acc (str_decl, acc); else if (TREE_CODE (acc->ref) == ARRAY_REF) return true; else if (TREE_CODE (acc->ref) == VAR_DECL) return true; return false; } /* This function creates empty field_access_site node. */ static inline struct field_access_site * make_field_acc_node (void) { int size = sizeof (struct field_access_site); return (struct field_access_site *) xcalloc (1, size); } /* This function returns the structure field access, defined by STMT, if it is already in hashtable of function accesses F_ACCS. */ static struct field_access_site * is_in_field_accs (gimple stmt, htab_t f_accs) { return (struct field_access_site *) htab_find_with_hash (f_accs, stmt, htab_hash_pointer (stmt)); } /* This function adds an access ACC to the hashtable F_ACCS of field accesses. */ static void add_field_acc_to_acc_sites (struct field_access_site *acc, htab_t f_accs) { void **slot; gcc_assert (!is_in_field_accs (acc->stmt, f_accs)); slot = htab_find_slot_with_hash (f_accs, acc->stmt, htab_hash_pointer (acc->stmt), INSERT); *slot = acc; } /* This function adds the VAR to vector of variables of an access site defined by statement STMT. If access entry with statement STMT does not exist in hashtable of accesses ACCS, this function creates it. */ static void add_access_to_acc_sites (gimple stmt, tree var, htab_t accs) { struct access_site *acc; acc = (struct access_site *) htab_find_with_hash (accs, stmt, htab_hash_pointer (stmt)); if (!acc) { void **slot; acc = (struct access_site *) xmalloc (sizeof (struct access_site)); acc->stmt = stmt; acc->vars = VEC_alloc (tree, heap, 10); slot = htab_find_slot_with_hash (accs, stmt, htab_hash_pointer (stmt), INSERT); *slot = acc; } VEC_safe_push (tree, heap, acc->vars, var); } /* This function adds NEW_DECL to function referenced vars, and marks it for renaming. */ static void finalize_var_creation (tree new_decl) { add_referenced_var (new_decl); if (is_global_var (new_decl)) mark_call_clobbered (new_decl, ESCAPE_UNKNOWN); mark_sym_for_renaming (new_decl); } /* This function finalizes VAR creation if it is a global VAR_DECL. */ static void finalize_global_creation (tree var) { if (TREE_CODE (var) == VAR_DECL && is_global_var (var)) finalize_var_creation (var); } /* This function inserts NEW_DECL to varpool. */ static inline void insert_global_to_varpool (tree new_decl) { struct varpool_node *new_node; new_node = varpool_node (new_decl); notice_global_symbol (new_decl); varpool_mark_needed_node (new_node); varpool_finalize_decl (new_decl); } /* This function finalizes the creation of new variables, defined by *SLOT->new_vars. */ static int finalize_new_vars_creation (void **slot, void *data ATTRIBUTE_UNUSED) { new_var n_var = *(new_var *) slot; unsigned i; tree var; for (i = 0; VEC_iterate (tree, n_var->new_vars, i, var); i++) finalize_var_creation (var); return 1; } /* This function looks for the variable of NEW_TYPE type, stored in VAR. It returns it, if found, and NULL_TREE otherwise. */ static tree find_var_in_new_vars_vec (new_var var, tree new_type) { tree n_var; unsigned i; for (i = 0; VEC_iterate (tree, var->new_vars, i, n_var); i++) { tree type = strip_type(get_type_of_var (n_var)); gcc_assert (type); if (type == new_type) return n_var; } return NULL_TREE; } /* This function returns new_var node, the orig_var of which is DECL. It looks for new_var's in NEW_VARS_HTAB. If not found, the function returns NULL. */ static new_var is_in_new_vars_htab (tree decl, htab_t new_vars_htab) { return (new_var) htab_find_with_hash (new_vars_htab, decl, htab_hash_pointer (decl)); } /* Given original variable ORIG_VAR, this function returns new variable corresponding to it of NEW_TYPE type. */ static tree find_new_var_of_type (tree orig_var, tree new_type) { new_var var; gcc_assert (orig_var && new_type); if (TREE_CODE (orig_var) == SSA_NAME) orig_var = SSA_NAME_VAR (orig_var); var = is_in_new_vars_htab (orig_var, new_global_vars); if (!var) var = is_in_new_vars_htab (orig_var, new_local_vars); gcc_assert (var); return find_var_in_new_vars_vec (var, new_type); } /* This function generates stmt: res = NUM * sizeof(TYPE) and returns it. res is filled into RES. */ static gimple gen_size (tree num, tree type, tree *res) { tree struct_size = TYPE_SIZE_UNIT (type); HOST_WIDE_INT struct_size_int = TREE_INT_CST_LOW (struct_size); gimple new_stmt; *res = create_tmp_var (TREE_TYPE (num), NULL); if (*res) add_referenced_var (*res); if (exact_log2 (struct_size_int) == -1) { tree size = build_int_cst (TREE_TYPE (num), struct_size_int); new_stmt = gimple_build_assign_with_ops (MULT_EXPR, *res, num, size); } else { tree C = build_int_cst (TREE_TYPE (num), exact_log2 (struct_size_int)); new_stmt = gimple_build_assign_with_ops (LSHIFT_EXPR, *res, num, C); } finalize_stmt (new_stmt); return new_stmt; } /* This function generates and returns a statement, that cast variable BEFORE_CAST to NEW_TYPE. The cast result variable is stored into RES_P. ORIG_CAST_STMT is the original cast statement. */ static gimple gen_cast_stmt (tree before_cast, tree new_type, gimple orig_cast_stmt, tree *res_p) { tree lhs, new_lhs; gimple new_stmt; lhs = gimple_assign_lhs (orig_cast_stmt); new_lhs = find_new_var_of_type (lhs, new_type); gcc_assert (new_lhs); new_stmt = gimple_build_assign_with_ops (NOP_EXPR, new_lhs, before_cast, 0); finalize_stmt (new_stmt); *res_p = new_lhs; return new_stmt; } /* This function builds an edge between BB and E->dest and updates phi nodes of E->dest. It returns newly created edge. */ static edge make_edge_and_fix_phis_of_dest (basic_block bb, edge e) { edge new_e; tree arg; gimple_stmt_iterator si; new_e = make_edge (bb, e->dest, e->flags); for (si = gsi_start_phis (new_e->dest); !gsi_end_p (si); gsi_next (&si)) { gimple phi = gsi_stmt (si); arg = PHI_ARG_DEF_FROM_EDGE (phi, e); add_phi_arg (phi, arg, new_e, gimple_phi_arg_location_from_edge (phi, e)); } return new_e; } /* This function inserts NEW_STMT before STMT. */ static void insert_before_stmt (gimple stmt, gimple new_stmt) { gimple_stmt_iterator bsi; if (!stmt || !new_stmt) return; bsi = gsi_for_stmt (stmt); gsi_insert_before (&bsi, new_stmt, GSI_SAME_STMT); } /* Insert NEW_STMTS after STMT. */ static void insert_seq_after_stmt (gimple stmt, gimple_seq new_stmts) { gimple_stmt_iterator bsi; if (!stmt || !new_stmts) return; bsi = gsi_for_stmt (stmt); gsi_insert_seq_after (&bsi, new_stmts, GSI_SAME_STMT); } /* Insert NEW_STMT after STMT. */ static void insert_after_stmt (gimple stmt, gimple new_stmt) { gimple_stmt_iterator bsi; if (!stmt || !new_stmt) return; bsi = gsi_for_stmt (stmt); gsi_insert_after (&bsi, new_stmt, GSI_SAME_STMT); } /* This function returns vector of allocation sites that appear in function FN_DECL. */ static fallocs_t get_fallocs (tree fn_decl) { return (fallocs_t) htab_find_with_hash (alloc_sites, fn_decl, htab_hash_pointer (fn_decl)); } /* If ALLOC_STMT is D.2225_7 = (D.2224_6); and it is a part of allocation of a structure, then it is usually followed by a cast stmt p_8 = (struct str_t *) D.2225_7; which is returned by this function. */ static gimple get_final_alloc_stmt (gimple alloc_stmt) { gimple final_stmt; use_operand_p use_p; tree alloc_res; if (!alloc_stmt) return NULL; if (!is_gimple_call (alloc_stmt)) return NULL; alloc_res = gimple_get_lhs (alloc_stmt); if (TREE_CODE (alloc_res) != SSA_NAME) return NULL; if (!single_imm_use (alloc_res, &use_p, &final_stmt)) return NULL; else return final_stmt; } /* This function returns true if STMT is one of allocation sites of function FN_DECL. It returns false otherwise. */ static bool is_part_of_malloc (gimple stmt, tree fn_decl) { fallocs_t fallocs = get_fallocs (fn_decl); if (fallocs) { alloc_site_t *call; unsigned i; for (i = 0; VEC_iterate (alloc_site_t, fallocs->allocs, i, call); i++) if (call->stmt == stmt || get_final_alloc_stmt (call->stmt) == stmt) return true; } return false; } /* Auxiliary structure for a lookup over field accesses. */ struct find_stmt_data { bool found; gimple stmt; }; /* This function looks for DATA->stmt among the statements involved in the field access, defined by SLOT. It stops when it's found. */ static int find_in_field_accs (void **slot, void *data) { struct field_access_site *f_acc = *(struct field_access_site **) slot; gimple stmt = ((struct find_stmt_data *)data)->stmt; if (f_acc->stmt == stmt || f_acc->ref_def_stmt == stmt || f_acc->cast_stmt == stmt) { ((struct find_stmt_data *)data)->found = true; return 0; } else return 1; } /* This function checks whether STMT is part of field accesses of structure STR. It returns true, if found, and false otherwise. */ static bool is_part_of_field_access (gimple stmt, d_str str) { int i; for (i = 0; i < str->num_fields; i++) { struct find_stmt_data data; data.found = false; data.stmt = stmt; if (str->fields[i].acc_sites) htab_traverse (str->fields[i].acc_sites, find_in_field_accs, &data); if (data.found) return true; } return false; } /* Auxiliary data for exclude_from_accs function. */ struct exclude_data { tree fn_decl; d_str str; }; /* This function returns component_ref with the BASE and field named FIELD_ID from structure TYPE. */ static inline tree build_comp_ref (tree base, tree field_id, tree type) { tree field; bool found = false; /* Find field of structure type with the same name as field_id. */ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) { if (DECL_NAME (field) == field_id) { found = true; break; } } gcc_assert (found); return build3 (COMPONENT_REF, TREE_TYPE (field), base, field, NULL_TREE); } /* This struct represent data used for walk_tree called from function find_pos_in_stmt. - ref is a tree to be found, - and pos is a pointer that points to ref in stmt. */ struct ref_pos { tree *pos; tree ref; }; /* This is a callback function for walk_tree, called from collect_accesses_in_bb function. DATA is a pointer to ref_pos structure. When *TP is equal to DATA->ref, the walk_tree stops, and found position, equal to TP, is assigned to DATA->pos. */ static tree find_pos_in_stmt_1 (tree *tp, int *walk_subtrees, void * data) { struct walk_stmt_info *wi = (struct walk_stmt_info *) data; struct ref_pos *r_pos = (struct ref_pos *) wi->info; tree ref = r_pos->ref; tree t = *tp; if (t == ref || (TREE_CODE (t) == SSA_NAME && SSA_NAME_VAR (t) == ref)) { r_pos->pos = tp; return t; } *walk_subtrees = 1; return NULL_TREE; } /* This function looks for the pointer of REF in STMT, It returns it, if found, and NULL otherwise. */ static tree * find_pos_in_stmt (gimple stmt, tree ref) { struct ref_pos r_pos; struct walk_stmt_info wi; r_pos.ref = ref; r_pos.pos = NULL; memset (&wi, 0, sizeof (wi)); wi.info = &r_pos; walk_gimple_op (stmt, find_pos_in_stmt_1, &wi); return r_pos.pos; } /* This structure is used to represent array or pointer-to wrappers of structure type. For example, if type1 is structure type, then for type1 ** we generate two type_wrapper structures with wrap = 0 each one. It's used to unwind the original type up to structure type, replace it with the new structure type and wrap it back in the opposite order. */ typedef struct type_wrapper { /* 0 stand for pointer wrapper, and 1 for array wrapper. */ bool wrap; /* Relevant for arrays as domain or index. */ tree domain; }type_wrapper_t; DEF_VEC_O (type_wrapper_t); DEF_VEC_ALLOC_O (type_wrapper_t, heap); /* This function replace field access ACC by the new field access of structure type NEW_TYPE. */ static void replace_field_acc (struct field_access_site *acc, tree new_type) { tree ref_var = acc->ref; tree new_ref; tree lhs, rhs; tree *pos; tree new_acc; tree field_id = DECL_NAME (acc->field_decl); VEC (type_wrapper_t, heap) *wrapper = VEC_alloc (type_wrapper_t, heap, 10); type_wrapper_t *wr_p = NULL; while (TREE_CODE (ref_var) == INDIRECT_REF || TREE_CODE (ref_var) == ARRAY_REF) { type_wrapper_t wr; if ( TREE_CODE (ref_var) == INDIRECT_REF) { wr.wrap = 0; wr.domain = 0; } else { wr.wrap = 1; wr.domain = TREE_OPERAND (ref_var, 1); } VEC_safe_push (type_wrapper_t, heap, wrapper, &wr); ref_var = TREE_OPERAND (ref_var, 0); } new_ref = find_new_var_of_type (ref_var, new_type); finalize_global_creation (new_ref); while (VEC_length (type_wrapper_t, wrapper) != 0) { tree type = TREE_TYPE (TREE_TYPE (new_ref)); wr_p = VEC_last (type_wrapper_t, wrapper); if (wr_p->wrap) /* Array. */ new_ref = build4 (ARRAY_REF, type, new_ref, wr_p->domain, NULL_TREE, NULL_TREE); else /* Pointer. */ new_ref = build1 (INDIRECT_REF, type, new_ref); VEC_pop (type_wrapper_t, wrapper); } new_acc = build_comp_ref (new_ref, field_id, new_type); VEC_free (type_wrapper_t, heap, wrapper); if (is_gimple_assign (acc->stmt)) { lhs = gimple_assign_lhs (acc->stmt); rhs = gimple_assign_rhs1 (acc->stmt); if (lhs == acc->comp_ref) gimple_assign_set_lhs (acc->stmt, new_acc); else if (rhs == acc->comp_ref) gimple_assign_set_rhs1 (acc->stmt, new_acc); else { pos = find_pos_in_stmt (acc->stmt, acc->comp_ref); gcc_assert (pos); *pos = new_acc; } } else { pos = find_pos_in_stmt (acc->stmt, acc->comp_ref); gcc_assert (pos); *pos = new_acc; } finalize_stmt (acc->stmt); } /* This function replace field access ACC by a new field access of structure type NEW_TYPE. */ static void replace_field_access_stmt (struct field_access_site *acc, tree new_type) { if (TREE_CODE (acc->ref) == INDIRECT_REF ||TREE_CODE (acc->ref) == ARRAY_REF ||TREE_CODE (acc->ref) == VAR_DECL) replace_field_acc (acc, new_type); else gcc_unreachable (); } /* This function looks for d_str, represented by TYPE, in the structures vector. If found, it returns an index of found structure. Otherwise it returns a length of the structures vector. */ static unsigned find_structure (tree type) { d_str str; unsigned i; type = TYPE_MAIN_VARIANT (type); for (i = 0; VEC_iterate (structure, structures, i, str); i++) if (is_equal_types (str->decl, type)) return i; return VEC_length (structure, structures); } /* In this function we create new statements that have the same form as ORIG_STMT, but of type NEW_TYPE. The statements treated by this function are simple assignments, like assignments: p.8_7 = p; or statements with rhs of tree codes PLUS_EXPR and MINUS_EXPR. */ static gimple create_base_plus_offset (gimple orig_stmt, tree new_type, tree offset) { tree lhs; tree new_lhs; gimple new_stmt; tree new_op0 = NULL_TREE, new_op1 = NULL_TREE; lhs = gimple_assign_lhs (orig_stmt); gcc_assert (TREE_CODE (lhs) == VAR_DECL || TREE_CODE (lhs) == SSA_NAME); new_lhs = find_new_var_of_type (lhs, new_type); gcc_assert (new_lhs); finalize_var_creation (new_lhs); switch (gimple_assign_rhs_code (orig_stmt)) { case PLUS_EXPR: case MINUS_EXPR: case POINTER_PLUS_EXPR: { tree op0 = gimple_assign_rhs1 (orig_stmt); tree op1 = gimple_assign_rhs2 (orig_stmt); unsigned str0, str1; unsigned length = VEC_length (structure, structures); str0 = find_structure (strip_type (get_type_of_var (op0))); str1 = find_structure (strip_type (get_type_of_var (op1))); gcc_assert ((str0 != length) || (str1 != length)); if (str0 != length) new_op0 = find_new_var_of_type (op0, new_type); if (str1 != length) new_op1 = find_new_var_of_type (op1, new_type); if (!new_op0) new_op0 = offset; if (!new_op1) new_op1 = offset; } break; default: gcc_unreachable(); } new_stmt = gimple_build_assign_with_ops (gimple_assign_rhs_code (orig_stmt), new_lhs, new_op0, new_op1); finalize_stmt (new_stmt); return new_stmt; } /* Given a field access F_ACC of the FIELD, this function replaces it by the new field access. */ static void create_new_field_access (struct field_access_site *f_acc, struct field_entry field) { tree new_type = field.field_mapping; gimple new_stmt; tree size_res = NULL; gimple mult_stmt; gimple cast_stmt; tree cast_res = NULL; if (f_acc->num) { mult_stmt = gen_size (f_acc->num, new_type, &size_res); insert_before_stmt (f_acc->ref_def_stmt, mult_stmt); } if (f_acc->cast_stmt) { cast_stmt = gen_cast_stmt (size_res, new_type, f_acc->cast_stmt, &cast_res); insert_after_stmt (f_acc->cast_stmt, cast_stmt); } if (f_acc->ref_def_stmt) { tree offset; if (cast_res) offset = cast_res; else offset = size_res; new_stmt = create_base_plus_offset (f_acc->ref_def_stmt, new_type, offset); insert_after_stmt (f_acc->ref_def_stmt, new_stmt); } /* In stmt D.2163_19 = D.2162_18->b; we replace variable D.2162_18 by an appropriate variable of new_type type. */ replace_field_access_stmt (f_acc, new_type); } /* This function creates a new condition statement corresponding to the original COND_STMT, adds new basic block and redirects condition edges. NEW_VAR is a new condition variable located in the condition statement at the position POS. */ static void create_new_stmts_for_cond_expr_1 (tree new_var, gimple cond_stmt, unsigned pos) { gimple new_stmt; edge true_e = NULL, false_e = NULL; basic_block new_bb; gimple_stmt_iterator si; extract_true_false_edges_from_block (gimple_bb (cond_stmt), &true_e, &false_e); new_stmt = gimple_build_cond (gimple_cond_code (cond_stmt), pos == 0 ? new_var : gimple_cond_lhs (cond_stmt), pos == 1 ? new_var : gimple_cond_rhs (cond_stmt), NULL_TREE, NULL_TREE); finalize_stmt (new_stmt); /* Create new basic block after bb. */ new_bb = create_empty_bb (gimple_bb (cond_stmt)); /* Add new condition stmt to the new_bb. */ si = gsi_start_bb (new_bb); gsi_insert_after (&si, new_stmt, GSI_NEW_STMT); /* Create false and true edges from new_bb. */ make_edge_and_fix_phis_of_dest (new_bb, true_e); make_edge_and_fix_phis_of_dest (new_bb, false_e); /* Redirect one of original edges to point to new_bb. */ if (gimple_cond_code (cond_stmt) == NE_EXPR) redirect_edge_succ (true_e, new_bb); else redirect_edge_succ (false_e, new_bb); } /* This function creates new condition statements corresponding to original condition STMT, one for each new type, and recursively redirect edges to newly generated basic blocks. */ static void create_new_stmts_for_cond_expr (gimple stmt) { tree arg0, arg1, arg; unsigned str0, str1; bool s0, s1; d_str str; tree type; unsigned pos; int i; unsigned length = VEC_length (structure, structures); gcc_assert (gimple_cond_code (stmt) == EQ_EXPR || gimple_cond_code (stmt) == NE_EXPR); arg0 = gimple_cond_lhs (stmt); arg1 = gimple_cond_rhs (stmt); str0 = find_structure (strip_type (get_type_of_var (arg0))); str1 = find_structure (strip_type (get_type_of_var (arg1))); s0 = (str0 != length) ? true : false; s1 = (str1 != length) ? true : false; gcc_assert (s0 || s1); /* For now we allow only comparison with 0 or NULL. */ gcc_assert (integer_zerop (arg0) || integer_zerop (arg1)); str = integer_zerop (arg0) ? VEC_index (structure, structures, str1): VEC_index (structure, structures, str0); arg = integer_zerop (arg0) ? arg1 : arg0; pos = integer_zerop (arg0) ? 1 : 0; for (i = 0; VEC_iterate (tree, str->new_types, i, type); i++) { tree new_arg; new_arg = find_new_var_of_type (arg, type); create_new_stmts_for_cond_expr_1 (new_arg, stmt, pos); } } /* Create a new general access to replace original access ACC for structure type NEW_TYPE. */ static gimple create_general_new_stmt (struct access_site *acc, tree new_type) { gimple old_stmt = acc->stmt; tree var; gimple new_stmt = gimple_copy (old_stmt); unsigned i; for (i = 0; VEC_iterate (tree, acc->vars, i, var); i++) { tree *pos; tree new_var = find_new_var_of_type (var, new_type); tree lhs, rhs = NULL_TREE; gcc_assert (new_var); finalize_var_creation (new_var); if (is_gimple_assign (new_stmt)) { lhs = gimple_assign_lhs (new_stmt); if (TREE_CODE (lhs) == SSA_NAME) lhs = SSA_NAME_VAR (lhs); if (gimple_assign_rhs_code (new_stmt) == SSA_NAME) rhs = SSA_NAME_VAR (gimple_assign_rhs1 (new_stmt)); /* It can happen that rhs is a constructor. Then we have to replace it to be of new_type. */ if (gimple_assign_rhs_code (new_stmt) == CONSTRUCTOR) { /* Dealing only with empty constructors right now. */ gcc_assert (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (rhs))); rhs = build_constructor (new_type, 0); gimple_assign_set_rhs1 (new_stmt, rhs); } if (lhs == var) gimple_assign_set_lhs (new_stmt, new_var); else if (rhs == var) gimple_assign_set_rhs1 (new_stmt, new_var); else { pos = find_pos_in_stmt (new_stmt, var); gcc_assert (pos); *pos = new_var; } } else { pos = find_pos_in_stmt (new_stmt, var); gcc_assert (pos); *pos = new_var; } } finalize_stmt (new_stmt); return new_stmt; } /* For each new type in STR this function creates new general accesses corresponding to the original access ACC. */ static void create_new_stmts_for_general_acc (struct access_site *acc, d_str str) { tree type; gimple stmt = acc->stmt; unsigned i; for (i = 0; VEC_iterate (tree, str->new_types, i, type); i++) { gimple new_stmt; new_stmt = create_general_new_stmt (acc, type); insert_after_stmt (stmt, new_stmt); } } /* This function creates a new general access of structure STR to replace the access ACC. */ static void create_new_general_access (struct access_site *acc, d_str str) { gimple stmt = acc->stmt; switch (gimple_code (stmt)) { case GIMPLE_COND: create_new_stmts_for_cond_expr (stmt); break; default: create_new_stmts_for_general_acc (acc, str); } } /* Auxiliary data for creation of accesses. */ struct create_acc_data { basic_block bb; d_str str; int field_index; }; /* This function creates a new general access, defined by SLOT. DATA is a pointer to create_acc_data structure. */ static int create_new_acc (void **slot, void *data) { struct access_site *acc = *(struct access_site **) slot; basic_block bb = ((struct create_acc_data *)data)->bb; d_str str = ((struct create_acc_data *)data)->str; if (gimple_bb (acc->stmt) == bb) create_new_general_access (acc, str); return 1; } /* This function creates a new field access, defined by SLOT. DATA is a pointer to create_acc_data structure. */ static int create_new_field_acc (void **slot, void *data) { struct field_access_site *f_acc = *(struct field_access_site **) slot; basic_block bb = ((struct create_acc_data *)data)->bb; d_str str = ((struct create_acc_data *)data)->str; int i = ((struct create_acc_data *)data)->field_index; if (gimple_bb (f_acc->stmt) == bb) create_new_field_access (f_acc, str->fields[i]); return 1; } /* This function creates new accesses for the structure type STR in basic block BB. */ static void create_new_accs_for_struct (d_str str, basic_block bb) { int i; struct create_acc_data dt; dt.str = str; dt.bb = bb; dt.field_index = -1; for (i = 0; i < str->num_fields; i++) { dt.field_index = i; if (str->fields[i].acc_sites) htab_traverse (str->fields[i].acc_sites, create_new_field_acc, &dt); } if (str->accs) htab_traverse (str->accs, create_new_acc, &dt); } /* This function inserts new variables from new_var, defined by SLOT, into varpool. */ static int update_varpool_with_new_var (void **slot, void *data ATTRIBUTE_UNUSED) { new_var n_var = *(new_var *) slot; tree var; unsigned i; for (i = 0; VEC_iterate (tree, n_var->new_vars, i, var); i++) insert_global_to_varpool (var); return 1; } /* This function prints a field access site, defined by SLOT. */ static int dump_field_acc (void **slot, void *data ATTRIBUTE_UNUSED) { struct field_access_site *f_acc = *(struct field_access_site **) slot; fprintf(dump_file, "\n"); if (f_acc->stmt) print_gimple_stmt (dump_file, f_acc->stmt, 0, 0); if (f_acc->ref_def_stmt) print_gimple_stmt (dump_file, f_acc->ref_def_stmt, 0, 0); if (f_acc->cast_stmt) print_gimple_stmt (dump_file, f_acc->cast_stmt, 0, 0); return 1; } /* Print field accesses from hashtable F_ACCS. */ static void dump_field_acc_sites (htab_t f_accs) { if (!dump_file) return; if (f_accs) htab_traverse (f_accs, dump_field_acc, NULL); } /* Hash value for fallocs_t. */ static hashval_t malloc_hash (const void *x) { return htab_hash_pointer (((const_fallocs_t)x)->func); } /* This function returns nonzero if function of func_alloc_sites' X is equal to Y. */ static int malloc_eq (const void *x, const void *y) { return ((const_fallocs_t)x)->func == (const_tree)y; } /* This function is a callback for traversal over a structure accesses. It frees an access represented by SLOT. */ static int free_accs (void **slot, void *data ATTRIBUTE_UNUSED) { struct access_site * acc = *(struct access_site **) slot; VEC_free (tree, heap, acc->vars); free (acc); return 1; } /* This is a callback function for traversal over field accesses. It frees a field access represented by SLOT. */ static int free_field_accs (void **slot, void *data ATTRIBUTE_UNUSED) { struct field_access_site *f_acc = *(struct field_access_site **) slot; free (f_acc); return 1; } /* This function inserts TYPE into vector of UNSUITABLE_TYPES, if it is not there yet. */ static void add_unsuitable_type (VEC (tree, heap) **unsuitable_types, tree type) { unsigned i; tree t; if (!type) return; type = TYPE_MAIN_VARIANT (type); for (i = 0; VEC_iterate (tree, *unsuitable_types, i, t); i++) if (is_equal_types (t, type)) break; if (i == VEC_length (tree, *unsuitable_types)) VEC_safe_push (tree, heap, *unsuitable_types, type); } /* Given a type TYPE, this function returns the name of the type. */ static const char * get_type_name (tree type) { if (! TYPE_NAME (type)) return NULL; if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) return IDENTIFIER_POINTER (TYPE_NAME (type)); else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL && DECL_NAME (TYPE_NAME (type))) return IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))); else return NULL; } /* This function is a temporary hack to overcome the types problem. When several compilation units are compiled together with -combine, the TYPE_MAIN_VARIANT of the same type can appear differently in different compilation units. Therefore this function first compares type names. If there are no names, structure bodies are recursively compared. */ static bool is_equal_types (tree type1, tree type2) { const char * name1,* name2; if ((!type1 && type2) ||(!type2 && type1)) return false; if (!type1 && !type2) return true; if (TREE_CODE (type1) != TREE_CODE (type2)) return false; if (type1 == type2) return true; if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) return true; name1 = get_type_name (type1); name2 = get_type_name (type2); if (name1 && name2 && !strcmp (name1, name2)) return true; if (name1 && name2 && strcmp (name1, name2)) return false; switch (TREE_CODE (type1)) { case POINTER_TYPE: case REFERENCE_TYPE: { return is_equal_types (TREE_TYPE (type1), TREE_TYPE (type2)); } break; case RECORD_TYPE: case UNION_TYPE: case QUAL_UNION_TYPE: case ENUMERAL_TYPE: { tree field1; /* Compare fields of structure. */ for (field1 = TYPE_FIELDS (type1); field1; field1 = TREE_CHAIN (field1)) { tree field2 = find_field_in_struct_1 (type2, field1); if (!field2) return false; } return true; } break; case INTEGER_TYPE: { if (TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2) && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)) return true; } break; case ARRAY_TYPE: { tree d1, d2; tree max1, min1, max2, min2; if (!is_equal_types (TREE_TYPE (type1), TREE_TYPE (type2))) return false; d1 = TYPE_DOMAIN (type1); d2 = TYPE_DOMAIN (type2); if (!d1 || !d2) return false; max1 = TYPE_MAX_VALUE (d1); max2 = TYPE_MAX_VALUE (d2); min1 = TYPE_MIN_VALUE (d1); min2 = TYPE_MIN_VALUE (d2); if (max1 && max2 && min1 && min2 && TREE_CODE (max1) == TREE_CODE (max2) && TREE_CODE (max1) == INTEGER_CST && TREE_CODE (min1) == TREE_CODE (min2) && TREE_CODE (min1) == INTEGER_CST && tree_int_cst_equal (max1, max2) && tree_int_cst_equal (min1, min2)) return true; } break; default: gcc_unreachable(); } return false; } /* This function free non-field accesses from hashtable ACCS. */ static void free_accesses (htab_t accs) { if (accs) htab_traverse (accs, free_accs, NULL); htab_delete (accs); } /* This function free field accesses hashtable F_ACCS. */ static void free_field_accesses (htab_t f_accs) { if (f_accs) htab_traverse (f_accs, free_field_accs, NULL); htab_delete (f_accs); } /* Update call graph with new edge generated by new MALLOC_STMT. The edge origin is CONTEXT function. */ static void update_cgraph_with_malloc_call (gimple malloc_stmt, tree context) { struct cgraph_node *src, *dest; tree malloc_fn_decl; if (!malloc_stmt) return; malloc_fn_decl = gimple_call_fndecl (malloc_stmt); src = cgraph_node (context); dest = cgraph_node (malloc_fn_decl); cgraph_create_edge (src, dest, malloc_stmt, 0, 0, gimple_bb (malloc_stmt)->loop_depth); } /* This function generates set of statements required to allocate number NUM of structures of type NEW_TYPE. The statements are stored in NEW_STMTS. The statement that contain call to malloc is returned. MALLOC_STMT is an original call to malloc. */ static gimple create_new_malloc (gimple malloc_stmt, tree new_type, gimple_seq *new_stmts, tree num) { tree new_malloc_size; tree malloc_fn_decl; gimple new_stmt; tree malloc_res; gimple call_stmt, final_stmt; tree cast_res; gcc_assert (num && malloc_stmt && new_type); *new_stmts = gimple_seq_alloc (); /* Generate argument to malloc as multiplication of num and size of new_type. */ new_stmt = gen_size (num, new_type, &new_malloc_size); gimple_seq_add_stmt (new_stmts, new_stmt); /* Generate new call for malloc. */ malloc_res = create_tmp_var (ptr_type_node, NULL); add_referenced_var (malloc_res); malloc_fn_decl = gimple_call_fndecl (malloc_stmt); call_stmt = gimple_build_call (malloc_fn_decl, 1, new_malloc_size); gimple_call_set_lhs (call_stmt, malloc_res); finalize_stmt_and_append (new_stmts, call_stmt); /* Create new cast statement. */ final_stmt = get_final_alloc_stmt (malloc_stmt); gcc_assert (final_stmt); new_stmt = gen_cast_stmt (malloc_res, new_type, final_stmt, &cast_res); gimple_seq_add_stmt (new_stmts, new_stmt); return call_stmt; } /* This function returns a tree representing the number of instances of structure STR_DECL allocated by allocation STMT. If new statements are generated, they are filled into NEW_STMTS_P. */ static tree gen_num_of_structs_in_malloc (gimple stmt, tree str_decl, gimple_seq *new_stmts_p) { tree arg; tree struct_size; HOST_WIDE_INT struct_size_int; if (!stmt) return NULL_TREE; /* Get malloc argument. */ if (!is_gimple_call (stmt)) return NULL_TREE; arg = gimple_call_arg (stmt, 0); if (TREE_CODE (arg) != SSA_NAME && !TREE_CONSTANT (arg)) return NULL_TREE; struct_size = TYPE_SIZE_UNIT (str_decl); struct_size_int = TREE_INT_CST_LOW (struct_size); gcc_assert (struct_size); if (TREE_CODE (arg) == SSA_NAME) { tree num; gimple div_stmt; if (is_result_of_mult (arg, &num, struct_size)) return num; num = create_tmp_var (integer_type_node, NULL); if (num) add_referenced_var (num); if (exact_log2 (struct_size_int) == -1) div_stmt = gimple_build_assign_with_ops (TRUNC_DIV_EXPR, num, arg, struct_size); else { tree C = build_int_cst (integer_type_node, exact_log2 (struct_size_int)); div_stmt = gimple_build_assign_with_ops (RSHIFT_EXPR, num, arg, C); } gimple_seq_add_stmt (new_stmts_p, div_stmt); finalize_stmt (div_stmt); return num; } if (CONSTANT_CLASS_P (arg) && multiple_of_p (TREE_TYPE (struct_size), arg, struct_size)) return int_const_binop (TRUNC_DIV_EXPR, arg, struct_size, 0); return NULL_TREE; } /* This function is a callback for traversal on new_var's hashtable. SLOT is a pointer to new_var. This function prints to dump_file an original variable and all new variables from the new_var pointed by *SLOT. */ static int dump_new_var (void **slot, void *data ATTRIBUTE_UNUSED) { new_var n_var = *(new_var *) slot; tree var_type; tree var; unsigned i; var_type = get_type_of_var (n_var->orig_var); fprintf (dump_file, "\nOrig var: "); print_generic_expr (dump_file, n_var->orig_var, 0); fprintf (dump_file, " of type "); print_generic_expr (dump_file, var_type, 0); fprintf (dump_file, "\n"); for (i = 0; VEC_iterate (tree, n_var->new_vars, i, var); i++) { var_type = get_type_of_var (var); fprintf (dump_file, " "); print_generic_expr (dump_file, var, 0); fprintf (dump_file, " of type "); print_generic_expr (dump_file, var_type, 0); fprintf (dump_file, "\n"); } return 1; } /* This function copies attributes form ORIG_DECL to NEW_DECL. */ static inline void copy_decl_attributes (tree new_decl, tree orig_decl) { DECL_ARTIFICIAL (new_decl) = 1; DECL_EXTERNAL (new_decl) = DECL_EXTERNAL (orig_decl); TREE_STATIC (new_decl) = TREE_STATIC (orig_decl); TREE_PUBLIC (new_decl) = TREE_PUBLIC (orig_decl); TREE_USED (new_decl) = TREE_USED (orig_decl); DECL_CONTEXT (new_decl) = DECL_CONTEXT (orig_decl); TREE_THIS_VOLATILE (new_decl) = TREE_THIS_VOLATILE (orig_decl); TREE_ADDRESSABLE (new_decl) = TREE_ADDRESSABLE (orig_decl); if (TREE_CODE (orig_decl) == VAR_DECL) { TREE_READONLY (new_decl) = TREE_READONLY (orig_decl); DECL_TLS_MODEL (new_decl) = DECL_TLS_MODEL (orig_decl); } } /* This function wraps NEW_STR_TYPE in pointers or arrays wrapper the same way as a structure type is wrapped in DECL. It returns the generated type. */ static inline tree gen_struct_type (tree decl, tree new_str_type) { tree type_orig = get_type_of_var (decl); tree new_type = new_str_type; VEC (type_wrapper_t, heap) *wrapper = VEC_alloc (type_wrapper_t, heap, 10); type_wrapper_t wr; type_wrapper_t *wr_p; while (POINTER_TYPE_P (type_orig) || TREE_CODE (type_orig) == ARRAY_TYPE) { if (POINTER_TYPE_P (type_orig)) { wr.wrap = 0; wr.domain = NULL_TREE; } else { gcc_assert (TREE_CODE (type_orig) == ARRAY_TYPE); wr.wrap = 1; wr.domain = TYPE_DOMAIN (type_orig); } VEC_safe_push (type_wrapper_t, heap, wrapper, &wr); type_orig = TREE_TYPE (type_orig); } while (VEC_length (type_wrapper_t, wrapper) != 0) { wr_p = VEC_last (type_wrapper_t, wrapper); if (wr_p->wrap) /* Array. */ new_type = build_array_type (new_type, wr_p->domain); else /* Pointer. */ new_type = build_pointer_type (new_type); VEC_pop (type_wrapper_t, wrapper); } VEC_free (type_wrapper_t, heap, wrapper); return new_type; } /* This function generates and returns new variable name based on ORIG_DECL name, combined with index I. The form of the new name is . . */ static tree gen_var_name (tree orig_decl, unsigned HOST_WIDE_INT i) { const char *old_name; char *prefix; char *new_name; if (!DECL_NAME (orig_decl) || !IDENTIFIER_POINTER (DECL_NAME (orig_decl))) return NULL; /* If the original variable has a name, create an appropriate new name for the new variable. */ old_name = IDENTIFIER_POINTER (DECL_NAME (orig_decl)); prefix = XALLOCAVEC (char, strlen (old_name) + 1); strcpy (prefix, old_name); ASM_FORMAT_PRIVATE_NAME (new_name, prefix, i); return get_identifier (new_name); } /* This function adds NEW_NODE to hashtable of new_var's NEW_VARS_HTAB. */ static void add_to_new_vars_htab (new_var new_node, htab_t new_vars_htab) { void **slot; slot = htab_find_slot_with_hash (new_vars_htab, new_node->orig_var, htab_hash_pointer (new_node->orig_var), INSERT); *slot = new_node; } /* This function creates and returns new_var_data node with empty new_vars and orig_var equal to VAR. */ static new_var create_new_var_node (tree var, d_str str) { new_var node; node = (new_var) xmalloc (sizeof (struct new_var_data)); node->orig_var = var; node->new_vars = VEC_alloc (tree, heap, VEC_length (tree, str->new_types)); return node; } /* Check whether the type of VAR is potential candidate for peeling. Returns true if yes, false otherwise. If yes, TYPE_P will contain candidate type. If VAR is initialized, the type of VAR will be added to UNSUITABLE_TYPES. */ static bool is_candidate (tree var, tree *type_p, VEC (tree, heap) **unsuitable_types) { tree type; bool initialized = false; *type_p = NULL; if (!var) return false; /* There is no support of initialized vars. */ if (TREE_CODE (var) == VAR_DECL && DECL_INITIAL (var) != NULL_TREE) initialized = true; type = get_type_of_var (var); if (type) { type = TYPE_MAIN_VARIANT (strip_type (type)); if (TREE_CODE (type) != RECORD_TYPE) return false; else { if (initialized && unsuitable_types && *unsuitable_types) { if (dump_file) { fprintf (dump_file, "The type "); print_generic_expr (dump_file, type, 0); fprintf (dump_file, " is initialized...Excluded."); } add_unsuitable_type (unsuitable_types, type); } *type_p = type; return true; } } else return false; } /* Hash value for field_access_site. */ static hashval_t field_acc_hash (const void *x) { return htab_hash_pointer (((const struct field_access_site *)x)->stmt); } /* This function returns nonzero if stmt of field_access_site X is equal to Y. */ static int field_acc_eq (const void *x, const void *y) { return ((const struct field_access_site *)x)->stmt == (const_gimple)y; } /* This function prints an access site, defined by SLOT. */ static int dump_acc (void **slot, void *data ATTRIBUTE_UNUSED) { struct access_site *acc = *(struct access_site **) slot; tree var; unsigned i; fprintf(dump_file, "\n"); if (acc->stmt) print_gimple_stmt (dump_file, acc->stmt, 0, 0); fprintf(dump_file, " : "); for (i = 0; VEC_iterate (tree, acc->vars, i, var); i++) { print_generic_expr (dump_file, var, 0); fprintf(dump_file, ", "); } return 1; } /* This function frees memory allocated for structure clusters, starting from CLUSTER. */ static void free_struct_cluster (struct field_cluster* cluster) { if (cluster) { if (cluster->fields_in_cluster) sbitmap_free (cluster->fields_in_cluster); if (cluster->sibling) free_struct_cluster (cluster->sibling); free (cluster); } } /* Free all allocated memory under the structure node pointed by D_NODE. */ static void free_data_struct (d_str d_node) { int i; if (!d_node) return; if (dump_file) { fprintf (dump_file, "\nRemoving data structure \""); print_generic_expr (dump_file, d_node->decl, 0); fprintf (dump_file, "\" from data_struct_list."); } /* Free all space under d_node. */ if (d_node->fields) { for (i = 0; i < d_node->num_fields; i++) free_field_accesses (d_node->fields[i].acc_sites); free (d_node->fields); } if (d_node->accs) free_accesses (d_node->accs); if (d_node->struct_clustering) free_struct_cluster (d_node->struct_clustering); if (d_node->new_types) VEC_free (tree, heap, d_node->new_types); } /* This function creates new general and field accesses in BB. */ static void create_new_accesses_in_bb (basic_block bb) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) create_new_accs_for_struct (str, bb); } /* This function adds allocation sites for peeled structures. M_DATA is vector of allocation sites of function CONTEXT. */ static void create_new_alloc_sites (fallocs_t m_data, tree context) { alloc_site_t *call; unsigned j; for (j = 0; VEC_iterate (alloc_site_t, m_data->allocs, j, call); j++) { gimple stmt = call->stmt; d_str str = call->str; tree num; gimple_seq new_stmts = NULL; gimple last_stmt = get_final_alloc_stmt (stmt); unsigned i; tree type; num = gen_num_of_structs_in_malloc (stmt, str->decl, &new_stmts); if (new_stmts) { gimple last_stmt_tmp = gimple_seq_last_stmt (new_stmts); insert_seq_after_stmt (last_stmt, new_stmts); last_stmt = last_stmt_tmp; } /* Generate an allocation sites for each new structure type. */ for (i = 0; VEC_iterate (tree, str->new_types, i, type); i++) { gimple new_malloc_stmt = NULL; gimple last_stmt_tmp = NULL; new_stmts = NULL; new_malloc_stmt = create_new_malloc (stmt, type, &new_stmts, num); last_stmt_tmp = gimple_seq_last_stmt (new_stmts); insert_seq_after_stmt (last_stmt, new_stmts); update_cgraph_with_malloc_call (new_malloc_stmt, context); last_stmt = last_stmt_tmp; } } } /* This function prints new variables from hashtable NEW_VARS_HTAB to dump_file. */ static void dump_new_vars (htab_t new_vars_htab) { if (!dump_file) return; if (new_vars_htab) htab_traverse (new_vars_htab, dump_new_var, NULL); } /* Given an original variable ORIG_DECL of structure type STR, this function generates new variables of the types defined by STR->new_type. Generated types are saved in new_var node NODE. ORIG_DECL should has VAR_DECL tree_code. */ static void create_new_var_1 (tree orig_decl, d_str str, new_var node) { unsigned i; tree type; for (i = 0; VEC_iterate (tree, str->new_types, i, type); i++) { tree new_decl = NULL; tree new_name; new_name = gen_var_name (orig_decl, i); type = gen_struct_type (orig_decl, type); if (is_global_var (orig_decl)) new_decl = build_decl (VAR_DECL, new_name, type); else { const char *name = new_name ? IDENTIFIER_POINTER (new_name) : NULL; new_decl = create_tmp_var (type, name); } copy_decl_attributes (new_decl, orig_decl); VEC_safe_push (tree, heap, node->new_vars, new_decl); } } /* This function creates new variables to substitute the original variable VAR_DECL and adds them to the new_var's hashtable NEW_VARS_HTAB. */ static void create_new_var (tree var_decl, htab_t new_vars_htab) { new_var node; d_str str; tree type; unsigned i; if (!var_decl || is_in_new_vars_htab (var_decl, new_vars_htab)) return; if (!is_candidate (var_decl, &type, NULL)) return; i = find_structure (type); if (i == VEC_length (structure, structures)) return; str = VEC_index (structure, structures, i); node = create_new_var_node (var_decl, str); create_new_var_1 (var_decl, str, node); add_to_new_vars_htab (node, new_vars_htab); } /* Hash value for new_var. */ static hashval_t new_var_hash (const void *x) { return htab_hash_pointer (((const_new_var)x)->orig_var); } /* This function returns nonzero if orig_var of new_var X is equal to Y. */ static int new_var_eq (const void *x, const void *y) { return ((const_new_var)x)->orig_var == (const_tree)y; } /* This function check whether a structure type represented by STR escapes due to ipa-type-escape analysis. If yes, this type is added to UNSUITABLE_TYPES vector. */ static void check_type_escape (d_str str, VEC (tree, heap) **unsuitable_types) { tree type = str->decl; if (!ipa_type_escape_type_contained_p (type)) { if (dump_file) { fprintf (dump_file, "\nEscaping type is "); print_generic_expr (dump_file, type, 0); } add_unsuitable_type (unsuitable_types, type); } } /* Hash value for access_site. */ static hashval_t acc_hash (const void *x) { return htab_hash_pointer (((const struct access_site *)x)->stmt); } /* Return nonzero if stmt of access_site X is equal to Y. */ static int acc_eq (const void *x, const void *y) { return ((const struct access_site *)x)->stmt == (const_gimple)y; } /* Given a structure declaration STRUCT_DECL, and number of fields in the structure NUM_FIELDS, this function creates and returns corresponding field_entry's. */ static struct field_entry * get_fields (tree struct_decl, int num_fields) { struct field_entry *list; tree t = TYPE_FIELDS (struct_decl); int idx = 0; list = (struct field_entry *) xmalloc (num_fields * sizeof (struct field_entry)); for (idx = 0 ; t; t = TREE_CHAIN (t), idx++) if (TREE_CODE (t) == FIELD_DECL) { list[idx].index = idx; list[idx].decl = t; list[idx].acc_sites = htab_create (32, field_acc_hash, field_acc_eq, NULL); list[idx].count = 0; list[idx].field_mapping = NULL_TREE; } return list; } /* Print non-field accesses from hashtable ACCS of structure. */ static void dump_access_sites (htab_t accs) { if (!dump_file) return; if (accs) htab_traverse (accs, dump_acc, NULL); } /* This function is a callback for alloc_sites hashtable traversal. SLOT is a pointer to fallocs_t. This function removes all allocations of the structure defined by DATA. */ static int remove_str_allocs_in_func (void **slot, void *data) { fallocs_t fallocs = *(fallocs_t *) slot; unsigned i = 0; alloc_site_t *call; while (VEC_iterate (alloc_site_t, fallocs->allocs, i, call)) { if (call->str == (d_str) data) VEC_ordered_remove (alloc_site_t, fallocs->allocs, i); else i++; } return 1; } /* This function remove all entries corresponding to the STR structure from alloc_sites hashtable. */ static void remove_str_allocs (d_str str) { if (!str) return; if (alloc_sites) htab_traverse (alloc_sites, remove_str_allocs_in_func, str); } /* This function removes the structure with index I from structures vector. */ static void remove_structure (unsigned i) { d_str str; if (i >= VEC_length (structure, structures)) return; str = VEC_index (structure, structures, i); /* Before removing the structure str, we have to remove its allocations from alloc_sites hashtable. */ remove_str_allocs (str); free_data_struct (str); VEC_ordered_remove (structure, structures, i); } /* Currently we support only EQ_EXPR or NE_EXPR conditions. COND_STMT is a condition statement to check. */ static bool is_safe_cond_expr (gimple cond_stmt) { tree arg0, arg1; unsigned str0, str1; bool s0, s1; unsigned length = VEC_length (structure, structures); if (gimple_cond_code (cond_stmt) != EQ_EXPR && gimple_cond_code (cond_stmt) != NE_EXPR) return false; arg0 = gimple_cond_lhs (cond_stmt); arg1 = gimple_cond_rhs (cond_stmt); str0 = find_structure (strip_type (get_type_of_var (arg0))); str1 = find_structure (strip_type (get_type_of_var (arg1))); s0 = (str0 != length) ? true : false; s1 = (str1 != length) ? true : false; if (!s0 && !s1) return false; /* For now we allow only comparison with 0 or NULL. */ if (!integer_zerop (arg0) && !integer_zerop (arg1)) return false; return true; } /* This function excludes statements, that are part of allocation sites or field accesses, from the hashtable of general accesses. SLOT represents general access that will be checked. DATA is a pointer to exclude_data structure. */ static int exclude_from_accs (void **slot, void *data) { struct access_site *acc = *(struct access_site **) slot; tree fn_decl = ((struct exclude_data *)data)->fn_decl; d_str str = ((struct exclude_data *)data)->str; if (is_part_of_malloc (acc->stmt, fn_decl) || is_part_of_field_access (acc->stmt, str)) { VEC_free (tree, heap, acc->vars); free (acc); htab_clear_slot (str->accs, slot); } return 1; } /* Callback function for walk_tree called from collect_accesses_in_bb function. DATA is the statement which is analyzed. */ static tree get_stmt_accesses (tree *tp, int *walk_subtrees, void *data) { struct walk_stmt_info *wi = (struct walk_stmt_info *) data; gimple stmt = (gimple) wi->info; tree t = *tp; if (!t) return NULL; switch (TREE_CODE (t)) { case BIT_FIELD_REF: { tree var = TREE_OPERAND(t, 0); tree type = TYPE_MAIN_VARIANT (strip_type (get_type_of_var (var))); unsigned i = find_structure (type); if (i != VEC_length (structure, structures)) { if (dump_file) { fprintf (dump_file, "\nThe type "); print_generic_expr (dump_file, type, 0); fprintf (dump_file, " has bitfield."); } remove_structure (i); } } break; case COMPONENT_REF: { tree ref = TREE_OPERAND (t, 0); tree field_decl = TREE_OPERAND (t, 1); if ((TREE_CODE (ref) == INDIRECT_REF || TREE_CODE (ref) == ARRAY_REF || TREE_CODE (ref) == VAR_DECL) && TREE_CODE (field_decl) == FIELD_DECL) { tree type = TYPE_MAIN_VARIANT (TREE_TYPE (ref)); unsigned i = find_structure (type); if (i != VEC_length (structure, structures)) { d_str str = VEC_index (structure, structures, i); struct field_entry * field = find_field_in_struct (str, field_decl); if (field) { struct field_access_site *acc = make_field_acc_node (); gcc_assert (acc); acc->stmt = stmt; acc->comp_ref = t; acc->ref = ref; acc->field_decl = field_decl; /* Check whether the access is of the form we can deal with. */ if (!decompose_access (str->decl, acc)) { if (dump_file) { fprintf (dump_file, "\nThe type "); print_generic_expr (dump_file, type, 0); fprintf (dump_file, " has complicate access in statement "); print_gimple_stmt (dump_file, stmt, 0, 0); } remove_structure (i); free (acc); } else { /* Increase count of field. */ basic_block bb = gimple_bb (stmt); field->count += bb->count; /* Add stmt to the acc_sites of field. */ add_field_acc_to_acc_sites (acc, field->acc_sites); } *walk_subtrees = 0; } } } } break; case COND_EXPR: { tree cond = COND_EXPR_COND (t); int i; for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (cond)); i++) { tree t = TREE_OPERAND (cond, i); *walk_subtrees = 1; walk_tree (&t, get_stmt_accesses, data, NULL); } *walk_subtrees = 0; } break; case VAR_DECL: case SSA_NAME: { unsigned i; if (TREE_CODE (t) == SSA_NAME) t = SSA_NAME_VAR (t); i = find_structure (strip_type (get_type_of_var (t))); if (i != VEC_length (structure, structures)) { d_str str; str = VEC_index (structure, structures, i); add_access_to_acc_sites (stmt, t, str->accs); } *walk_subtrees = 0; } break; default: return NULL; } return NULL; } /* Free structures hashtable. */ static void free_structures (void) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) free_data_struct (str); VEC_free (structure, heap, structures); structures = NULL; } /* This function is a callback for traversal over new_var's hashtable. SLOT is a pointer to new_var. This function frees memory allocated for new_var and pointed by *SLOT. */ static int free_new_var (void **slot, void *data ATTRIBUTE_UNUSED) { new_var n_var = *(new_var *) slot; /* Free vector of new_vars. */ VEC_free (tree, heap, n_var->new_vars); free (n_var); return 1; } /* Free new_vars hashtable NEW_VARS_HTAB. */ static void free_new_vars_htab (htab_t new_vars_htab) { if (new_vars_htab) htab_traverse (new_vars_htab, free_new_var, NULL); htab_delete (new_vars_htab); new_vars_htab = NULL; } /* This function creates new general and field accesses that appear in cfun. */ static void create_new_accesses_for_func (void) { basic_block bb; FOR_EACH_BB_FN (bb, cfun) create_new_accesses_in_bb (bb); } /* Create new allocation sites for the function represented by NODE. */ static void create_new_alloc_sites_for_func (struct cgraph_node *node) { fallocs_t fallocs = get_fallocs (node->decl); if (fallocs) create_new_alloc_sites (fallocs, node->decl); } /* For each local variable of structure type from the vector of structures this function generates new variable(s) to replace it. */ static void create_new_local_vars (void) { tree var; referenced_var_iterator rvi; new_local_vars = htab_create (num_referenced_vars, new_var_hash, new_var_eq, NULL); FOR_EACH_REFERENCED_VAR (var, rvi) { if (!is_global_var (var)) create_new_var (var, new_local_vars); } if (new_local_vars) htab_traverse (new_local_vars, finalize_new_vars_creation, NULL); dump_new_vars (new_local_vars); } /* This function prints the SHIFT number of spaces to the DUMP_FILE. */ static inline void print_shift (unsigned HOST_WIDE_INT shift) { unsigned HOST_WIDE_INT sh = shift; while (sh--) fprintf (dump_file, " "); } /* This function updates field_mapping of FIELDS in CLUSTER with NEW_TYPE. */ static inline void update_fields_mapping (struct field_cluster *cluster, tree new_type, struct field_entry * fields, int num_fields) { int i; for (i = 0; i < num_fields; i++) if (TEST_BIT (cluster->fields_in_cluster, i)) fields[i].field_mapping = new_type; } /* This functions builds structure with FIELDS, NAME and attributes similar to ORIG_STRUCT. It returns the newly created structure. */ static tree build_basic_struct (tree fields, tree name, tree orig_struct) { tree attributes = NULL_TREE; tree ref = 0; tree x; if (TYPE_ATTRIBUTES (orig_struct)) attributes = unshare_expr (TYPE_ATTRIBUTES (orig_struct)); ref = make_node (RECORD_TYPE); TYPE_SIZE (ref) = 0; decl_attributes (&ref, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); TYPE_PACKED (ref) = TYPE_PACKED (orig_struct); for (x = fields; x; x = TREE_CHAIN (x)) { DECL_CONTEXT (x) = ref; DECL_PACKED (x) |= TYPE_PACKED (ref); } TYPE_FIELDS (ref) = fields; layout_type (ref); TYPE_NAME (ref) = name; return ref; } /* This function copies FIELDS from CLUSTER into TREE_CHAIN as part of preparation for new structure building. NUM_FIELDS is a total number of fields in the structure. The function returns newly generated fields. */ static tree create_fields (struct field_cluster * cluster, struct field_entry * fields, int num_fields) { int i; tree new_types = NULL_TREE; tree last = NULL_TREE; for (i = 0; i < num_fields; i++) if (TEST_BIT (cluster->fields_in_cluster, i)) { tree new_decl = unshare_expr (fields[i].decl); if (!new_types) new_types = new_decl; else TREE_CHAIN (last) = new_decl; last = new_decl; } TREE_CHAIN (last) = NULL_TREE; return new_types; } /* This function creates a cluster name. The name is based on the original structure name, if it is present. It has a form: _sub. The original structure name is taken from the type of DECL. If an original structure name is not present, it's generated to be: struct. The function returns identifier of the new cluster name. */ static inline tree gen_cluster_name (tree decl, int clust_num, int str_num) { const char * orig_name = get_type_name (decl); char * tmp_name = NULL; char * prefix; char * new_name; size_t len; if (!orig_name) ASM_FORMAT_PRIVATE_NAME(tmp_name, "struct", str_num); len = strlen (tmp_name ? tmp_name : orig_name) + strlen ("_sub"); prefix = XALLOCAVEC (char, len + 1); memcpy (prefix, tmp_name ? tmp_name : orig_name, strlen (tmp_name ? tmp_name : orig_name)); strcpy (prefix + strlen (tmp_name ? tmp_name : orig_name), "_sub"); ASM_FORMAT_PRIVATE_NAME (new_name, prefix, clust_num); return get_identifier (new_name); } /* This function checks whether the structure STR has bitfields. If yes, this structure type is added to UNSUITABLE_TYPES vector. */ static void check_bitfields (d_str str, VEC (tree, heap) **unsuitable_types) { tree type = str->decl; int i; for (i = 0; i < str->num_fields; i++) if (DECL_BIT_FIELD (str->fields[i].decl)) { add_unsuitable_type (unsuitable_types, type); if (dump_file) { fprintf (dump_file, "\nType "); print_generic_expr (dump_file, type, 0); fprintf (dump_file, "\nescapes due to bitfield "); print_generic_expr (dump_file, str->fields[i].decl, 0); } break; } } /* This function adds to UNSUITABLE_TYPES those types that escape due to results of ipa-type-escape analysis. See ipa-type-escape.[c,h]. */ static void exclude_escaping_types_1 (VEC (tree, heap) **unsuitable_types) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) check_type_escape (str, unsuitable_types); } /* If a structure type is a return type of any function, we cannot transform it. Such type is added to UNSUITABLE_TYPES vector. */ static void exclude_returned_types (VEC (tree, heap) **unsuitable_types) { struct cgraph_node *c_node; for (c_node = cgraph_nodes; c_node; c_node = c_node->next) { tree ret_t = TREE_TYPE (TREE_TYPE (c_node->decl)); if (ret_t) { ret_t = strip_type (ret_t); if (TREE_CODE (ret_t) == RECORD_TYPE) { add_unsuitable_type (unsuitable_types, TYPE_MAIN_VARIANT (ret_t)); if (dump_file) { fprintf (dump_file, "\nThe type \""); print_generic_expr (dump_file, ret_t, 0); fprintf (dump_file, "\" is return type of function...Excluded."); } } } } } /* This function looks for parameters of local functions which are of structure types, or derived from them (arrays of structures, pointers to structures, or their combinations). We are not handling peeling of such structures right now. The found structures types are added to UNSUITABLE_TYPES vector. */ static void exclude_types_passed_to_local_func (VEC (tree, heap) **unsuitable_types) { struct cgraph_node *c_node; for (c_node = cgraph_nodes; c_node; c_node = c_node->next) if (cgraph_function_body_availability (c_node) == AVAIL_LOCAL) { tree fn = c_node->decl; tree arg; for (arg = DECL_ARGUMENTS (fn); arg; arg = TREE_CHAIN (arg)) { tree type = TREE_TYPE (arg); type = strip_type (type); if (TREE_CODE (type) == RECORD_TYPE) { add_unsuitable_type (unsuitable_types, TYPE_MAIN_VARIANT (type)); if (dump_file) { fprintf (dump_file, "\nPointer to type \""); print_generic_expr (dump_file, type, 0); fprintf (dump_file, "\" is passed to local function...Excluded."); } } } } } /* This function analyzes structure form of structures potential for transformation. If we are not capable to transform structure of some form, we remove it from the structures hashtable. Right now we cannot handle nested structs, when nesting is through any level of pointers or arrays. TBD: release these constrains in future. Note, that in this function we suppose that all structures in the program are members of the structures hashtable right now, without excluding escaping types. */ static void check_struct_form (d_str str, VEC (tree, heap) **unsuitable_types) { int i; for (i = 0; i < str->num_fields; i++) { tree f_type = strip_type(TREE_TYPE (str->fields[i].decl)); if (TREE_CODE (f_type) == RECORD_TYPE) { add_unsuitable_type (unsuitable_types, TYPE_MAIN_VARIANT (f_type)); add_unsuitable_type (unsuitable_types, str->decl); if (dump_file) { fprintf (dump_file, "\nType "); print_generic_expr (dump_file, f_type, 0); fprintf (dump_file, " is a field in the structure "); print_generic_expr (dump_file, str->decl, 0); fprintf (dump_file, ". Escaping..."); } } } } /* This function adds a structure TYPE to the vector of structures, if it's not already there. */ static void add_structure (tree type) { struct data_structure node; unsigned i; int num_fields; type = TYPE_MAIN_VARIANT (type); i = find_structure (type); if (i != VEC_length (structure, structures)) return; num_fields = fields_length (type); node.decl = type; node.num_fields = num_fields; node.fields = get_fields (type, num_fields); node.struct_clustering = NULL; node.accs = htab_create (32, acc_hash, acc_eq, NULL); node.new_types = VEC_alloc (tree, heap, num_fields); node.count = 0; VEC_safe_push (structure, heap, structures, &node); if (dump_file) { fprintf (dump_file, "\nAdding data structure \""); print_generic_expr (dump_file, type, 0); fprintf (dump_file, "\" to data_struct_list."); } } /* This function adds an allocation site to alloc_sites hashtable. The allocation site appears in STMT of function FN_DECL and allocates the structure represented by STR. */ static void add_alloc_site (tree fn_decl, gimple stmt, d_str str) { fallocs_t fallocs = NULL; alloc_site_t m_call; m_call.stmt = stmt; m_call.str = str; fallocs = (fallocs_t) htab_find_with_hash (alloc_sites, fn_decl, htab_hash_pointer (fn_decl)); if (!fallocs) { void **slot; fallocs = (fallocs_t) xmalloc (sizeof (struct func_alloc_sites)); fallocs->func = fn_decl; fallocs->allocs = VEC_alloc (alloc_site_t, heap, 1); slot = htab_find_slot_with_hash (alloc_sites, fn_decl, htab_hash_pointer (fn_decl), INSERT); *slot = fallocs; } VEC_safe_push (alloc_site_t, heap, fallocs->allocs, &m_call); if (dump_file) { fprintf (dump_file, "\nAdding stmt "); print_gimple_stmt (dump_file, stmt, 0, 0); fprintf (dump_file, " to list of mallocs."); } } /* This function returns true if the result of STMT, that contains a call to an allocation function, is cast to one of the structure types. STMT should be of the form: T.2 = (T.1); If true, I_P contains an index of an allocated structure. Otherwise I_P contains the length of the vector of structures. */ static bool is_alloc_of_struct (gimple stmt, unsigned *i_p) { tree lhs; tree type; gimple final_stmt; final_stmt = get_final_alloc_stmt (stmt); if (!final_stmt) return false; /* final_stmt should be of the form: T.3 = (struct_type *) T.2; */ if (gimple_code (final_stmt) != GIMPLE_ASSIGN) return false; lhs = gimple_assign_lhs (final_stmt); type = get_type_of_var (lhs); if (!type) return false; if (!POINTER_TYPE_P (type) || TREE_CODE (strip_type (type)) != RECORD_TYPE) return false; *i_p = find_structure (strip_type (type)); if (*i_p == VEC_length (structure, structures)) return false; return true; } /* This function prints non-field and field accesses of the structure STR. */ static void dump_accs (d_str str) { int i; fprintf (dump_file, "\nAccess sites of struct "); print_generic_expr (dump_file, str->decl, 0); for (i = 0; i < str->num_fields; i++) { fprintf (dump_file, "\nAccess site of field "); print_generic_expr (dump_file, str->fields[i].decl, 0); dump_field_acc_sites (str->fields[i].acc_sites); fprintf (dump_file, ":\n"); } fprintf (dump_file, "\nGeneral access sites\n"); dump_access_sites (str->accs); } /* This function checks whether an access statement, pointed by SLOT, is a condition we are capable to transform. It returns false if not, setting bool *DATA to false. */ static int safe_cond_expr_check (void **slot, void *data) { struct access_site *acc = *(struct access_site **) slot; if (gimple_code (acc->stmt) == GIMPLE_COND && !is_safe_cond_expr (acc->stmt)) { if (dump_file) { fprintf (dump_file, "\nUnsafe conditional statement "); print_gimple_stmt (dump_file, acc->stmt, 0, 0); } *(bool *) data = false; return 0; } return 1; } /* This function excludes statements that are part of allocation sites and field accesses from the hashtable of general accesses of the structure type STR. Only accesses that belong to the function represented by NODE are treated. */ static void exclude_alloc_and_field_accs_1 (d_str str, struct cgraph_node *node) { struct exclude_data dt; dt.str = str; dt.fn_decl = node->decl; if (dt.str->accs) htab_traverse (dt.str->accs, exclude_from_accs, &dt); } /* Collect accesses to the structure types that appear in basic block BB. */ static void collect_accesses_in_bb (basic_block bb) { gimple_stmt_iterator bsi; struct walk_stmt_info wi; memset (&wi, 0, sizeof (wi)); for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) { gimple stmt = gsi_stmt (bsi); /* In asm stmt we cannot always track the arguments, so we just give up. */ if (gimple_code (stmt) == GIMPLE_ASM) { free_structures (); break; } wi.info = (void *) stmt; walk_gimple_op (stmt, get_stmt_accesses, &wi); } } /* This function generates cluster substructure that contains FIELDS. The cluster added to the set of clusters of the structure STR. */ static void gen_cluster (sbitmap fields, d_str str) { struct field_cluster *crr_cluster = NULL; crr_cluster = (struct field_cluster *) xcalloc (1, sizeof (struct field_cluster)); crr_cluster->sibling = str->struct_clustering; str->struct_clustering = crr_cluster; crr_cluster->fields_in_cluster = fields; } /* This function peels a field with the index I from the structure DS. */ static void peel_field (int i, d_str ds) { struct field_cluster *crr_cluster = NULL; crr_cluster = (struct field_cluster *) xcalloc (1, sizeof (struct field_cluster)); crr_cluster->sibling = ds->struct_clustering; ds->struct_clustering = crr_cluster; crr_cluster->fields_in_cluster = sbitmap_alloc ((unsigned int) ds->num_fields); sbitmap_zero (crr_cluster->fields_in_cluster); SET_BIT (crr_cluster->fields_in_cluster, i); } /* This function calculates maximum field count in the structure STR. */ static gcov_type get_max_field_count (d_str str) { gcov_type max = 0; int i; for (i = 0; i < str->num_fields; i++) if (str->fields[i].count > max) max = str->fields[i].count; return max; } /* Do struct-reorg transformation for individual function represented by NODE. All structure types relevant for this function are transformed. */ static void do_reorg_for_func (struct cgraph_node *node) { create_new_local_vars (); create_new_alloc_sites_for_func (node); create_new_accesses_for_func (); update_ssa (TODO_update_ssa); cleanup_tree_cfg (); /* Free auxiliary data representing local variables. */ free_new_vars_htab (new_local_vars); } /* Print structure TYPE, its name, if it exists, and body. INDENT defines the level of indentation (similar to the option -i of indent command). SHIFT parameter defines a number of spaces by which a structure will be shifted right. */ static void dump_struct_type (tree type, unsigned HOST_WIDE_INT indent, unsigned HOST_WIDE_INT shift) { const char *struct_name; tree field; if (!type || !dump_file) return; if (TREE_CODE (type) != RECORD_TYPE) { print_generic_expr (dump_file, type, 0); return; } print_shift (shift); struct_name = get_type_name (type); fprintf (dump_file, "struct "); if (struct_name) fprintf (dump_file, "%s\n",struct_name); print_shift (shift); fprintf (dump_file, "{\n"); for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) { unsigned HOST_WIDE_INT s = indent; tree f_type = TREE_TYPE (field); print_shift (shift); while (s--) fprintf (dump_file, " "); dump_struct_type (f_type, indent, shift + indent); fprintf(dump_file, " "); print_generic_expr (dump_file, field, 0); fprintf(dump_file, ";\n"); } print_shift (shift); fprintf (dump_file, "}\n"); } /* This function creates new structure types to replace original type, indicated by STR->decl. The names of the new structure types are derived from the original structure type. If the original structure type has no name, we assume that its name is 'struct.'. */ static void create_new_type (d_str str, int *str_num) { int cluster_num = 0; struct field_cluster *cluster = str->struct_clustering; while (cluster) { tree name = gen_cluster_name (str->decl, cluster_num, *str_num); tree fields; tree new_type; cluster_num++; fields = create_fields (cluster, str->fields, str->num_fields); new_type = build_basic_struct (fields, name, str->decl); update_fields_mapping (cluster, new_type, str->fields, str->num_fields); VEC_safe_push (tree, heap, str->new_types, new_type); cluster = cluster->sibling; } (*str_num)++; } /* This function is a callback for alloc_sites hashtable traversal. SLOT is a pointer to fallocs_t. This function frees memory pointed by *SLOT. */ static int free_falloc_sites (void **slot, void *data ATTRIBUTE_UNUSED) { fallocs_t fallocs = *(fallocs_t *) slot; VEC_free (alloc_site_t, heap, fallocs->allocs); free (fallocs); return 1; } /* Remove structures collected in UNSUITABLE_TYPES from structures vector. */ static void remove_unsuitable_types (VEC (tree, heap) *unsuitable_types) { d_str str; tree type; unsigned i, j; for (j = 0; VEC_iterate (tree, unsuitable_types, j, type); j++) for (i = 0; VEC_iterate (structure, structures, i, str); i++) if (is_equal_types (str->decl, type)) { remove_structure (i); break; } } /* Exclude structure types with bitfields. We would not want to interfere with other optimizations that can be done in this case. The structure types with bitfields are added to UNSUITABLE_TYPES vector. */ static void exclude_types_with_bit_fields (VEC (tree, heap) **unsuitable_types) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) check_bitfields (str, unsuitable_types); } /* This function checks three types of escape. A structure type escapes: 1. if it's a type of parameter of a local function. 2. if it's a type of function return value. 3. if it escapes as a result of ipa-type-escape analysis. The escaping structure types are added to UNSUITABLE_TYPES vector. */ static void exclude_escaping_types (VEC (tree, heap) **unsuitable_types) { exclude_types_passed_to_local_func (unsuitable_types); exclude_returned_types (unsuitable_types); exclude_escaping_types_1 (unsuitable_types); } /* This function analyzes whether the form of structure is such that we are capable to transform it. Nested structures are checked here. Unsuitable structure types are added to UNSUITABLE_TYPE vector. */ static void analyze_struct_form (VEC (tree, heap) **unsuitable_types) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) check_struct_form (str, unsuitable_types); } /* This function looks for structure types instantiated in the program. The candidate types are added to the structures vector. Unsuitable types are collected into UNSUITABLE_TYPES vector. */ static void build_data_structure (VEC (tree, heap) **unsuitable_types) { tree var, type; tree var_list; struct varpool_node *current_varpool; struct cgraph_node *c_node; /* Check global variables. */ FOR_EACH_STATIC_VARIABLE (current_varpool) { var = current_varpool->decl; if (is_candidate (var, &type, unsuitable_types)) add_structure (type); } /* Now add structures that are types of function parameters and local variables. */ for (c_node = cgraph_nodes; c_node; c_node = c_node->next) { enum availability avail = cgraph_function_body_availability (c_node); /* We need AVAIL_AVAILABLE for main function. */ if (avail == AVAIL_LOCAL || avail == AVAIL_AVAILABLE) { struct function *fn = DECL_STRUCT_FUNCTION (c_node->decl); for (var = DECL_ARGUMENTS (c_node->decl); var; var = TREE_CHAIN (var)) if (is_candidate (var, &type, unsuitable_types)) add_structure (type); /* Check function local variables. */ for (var_list = fn->local_decls; var_list; var_list = TREE_CHAIN (var_list)) { var = TREE_VALUE (var_list); if (is_candidate (var, &type, unsuitable_types)) add_structure (type); } } } } /* This function returns true if the program contains a call to user defined allocation function, or other functions that can interfere with struct-reorg optimizations. */ static bool program_redefines_malloc_p (void) { struct cgraph_node *c_node; struct cgraph_node *c_node2; struct cgraph_edge *c_edge; tree fndecl; tree fndecl2; for (c_node = cgraph_nodes; c_node; c_node = c_node->next) { fndecl = c_node->decl; for (c_edge = c_node->callees; c_edge; c_edge = c_edge->next_callee) { c_node2 = c_edge->callee; fndecl2 = c_node2->decl; if (is_gimple_call (c_edge->call_stmt)) { const char * fname = get_name (fndecl2); if ((gimple_call_flags (c_edge->call_stmt) & ECF_MALLOC) && (DECL_FUNCTION_CODE (fndecl2) != BUILT_IN_MALLOC) && (DECL_FUNCTION_CODE (fndecl2) != BUILT_IN_CALLOC) && (DECL_FUNCTION_CODE (fndecl2) != BUILT_IN_ALLOCA)) return true; /* Check that there is no __builtin_object_size, __builtin_offsetof, or realloc's in the program. */ if (DECL_FUNCTION_CODE (fndecl2) == BUILT_IN_OBJECT_SIZE || !strcmp (fname, "__builtin_offsetof") || !strcmp (fname, "realloc")) return true; } } } return false; } /* In this function we assume that an allocation statement var = (type_cast) malloc (size); is converted into the following set of statements: T.1 = size; T.2 = malloc (T.1); T.3 = (type_cast) T.2; var = T.3; In this function we collect into alloc_sites the allocation sites of variables of structure types that are present in structures vector. */ static void collect_alloc_sites (void) { struct cgraph_node *node; struct cgraph_edge *cs; for (node = cgraph_nodes; node; node = node->next) if (node->analyzed && node->decl) { for (cs = node->callees; cs; cs = cs->next_callee) { gimple stmt = cs->call_stmt; if (stmt) { tree decl; if (is_gimple_call (stmt) && (decl = gimple_call_fndecl (stmt)) && gimple_call_lhs (stmt)) { unsigned i; if (is_alloc_of_struct (stmt, &i)) { /* We support only malloc now. */ if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MALLOC) { d_str str; str = VEC_index (structure, structures, i); add_alloc_site (node->decl, stmt, str); } else { if (dump_file) { fprintf (dump_file, "\nUnsupported allocation function "); print_gimple_stmt (dump_file, stmt, 0, 0); } remove_structure (i); } } } } } } } /* Print collected accesses. */ static void dump_accesses (void) { d_str str; unsigned i; if (!dump_file) return; for (i = 0; VEC_iterate (structure, structures, i, str); i++) dump_accs (str); } /* This function checks whether the accesses of structures in condition expressions are of the kind we are capable to transform. If not, such structures are removed from the vector of structures. */ static void check_cond_exprs (void) { d_str str; unsigned i; i = 0; while (VEC_iterate (structure, structures, i, str)) { bool safe_p = true; if (str->accs) htab_traverse (str->accs, safe_cond_expr_check, &safe_p); if (!safe_p) remove_structure (i); else i++; } } /* We exclude from non-field accesses of the structure all statements that will be treated as part of the structure allocation sites or field accesses. */ static void exclude_alloc_and_field_accs (struct cgraph_node *node) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) exclude_alloc_and_field_accs_1 (str, node); } /* This function collects accesses of the fields of the structures that appear at function FN. */ static void collect_accesses_in_func (struct function *fn) { basic_block bb; if (! fn) return; /* Collect accesses for each basic blocks separately. */ FOR_EACH_BB_FN (bb, fn) collect_accesses_in_bb (bb); } /* This function summarizes counts of the fields into the structure count. */ static void sum_counts (d_str str, gcov_type *hottest) { int i; str->count = 0; for (i = 0; i < str->num_fields; i++) { if (dump_file) { fprintf (dump_file, "\nCounter of field \""); print_generic_expr (dump_file, str->fields[i].decl, 0); fprintf (dump_file, "\" is " HOST_WIDEST_INT_PRINT_DEC, str->fields[i].count); } str->count += str->fields[i].count; } if (dump_file) { fprintf (dump_file, "\nCounter of struct \""); print_generic_expr (dump_file, str->decl, 0); fprintf (dump_file, "\" is " HOST_WIDEST_INT_PRINT_DEC, str->count); } if (str->count > *hottest) *hottest = str->count; } /* This function peels the field into separate structure if it's sufficiently hot, i.e. if its count provides at least 90% of the maximum field count in the structure. */ static void peel_hot_fields (d_str str) { gcov_type max_field_count; sbitmap fields_left = sbitmap_alloc (str->num_fields); int i; sbitmap_ones (fields_left); max_field_count = (gcov_type) (get_max_field_count (str)/100)*90; str->struct_clustering = NULL; for (i = 0; i < str->num_fields; i++) { if (str->count >= max_field_count) { RESET_BIT (fields_left, i); peel_field (i, str); } } i = sbitmap_first_set_bit (fields_left); if (i != -1) gen_cluster (fields_left, str); else sbitmap_free (fields_left); } /* This function is a helper for do_reorg. It goes over functions in call graph and performs actual transformation on them. */ static void do_reorg_1 (void) { struct cgraph_node *node; /* Initialize the default bitmap obstack. */ bitmap_obstack_initialize (NULL); for (node = cgraph_nodes; node; node = node->next) if (node->analyzed && node->decl && !node->next_clone) { push_cfun (DECL_STRUCT_FUNCTION (node->decl)); current_function_decl = node->decl; if (dump_file) fprintf (dump_file, "\nFunction to do reorg is %s: \n", (const char *) IDENTIFIER_POINTER (DECL_NAME (node->decl))); do_reorg_for_func (node); free_dominance_info (CDI_DOMINATORS); free_dominance_info (CDI_POST_DOMINATORS); current_function_decl = NULL; pop_cfun (); } set_cfun (NULL); bitmap_obstack_release (NULL); } /* This function creates new global struct variables. For each original variable, the set of new variables is created with the new structure types corresponding to the structure type of original variable. Only VAR_DECL variables are treated by this function. */ static void create_new_global_vars (void) { struct varpool_node *current_varpool; unsigned HOST_WIDE_INT i; unsigned HOST_WIDE_INT varpool_size = 0; for (i = 0; i < 2; i++) { if (i) new_global_vars = htab_create (varpool_size, new_var_hash, new_var_eq, NULL); FOR_EACH_STATIC_VARIABLE(current_varpool) { tree var_decl = current_varpool->decl; if (!var_decl || TREE_CODE (var_decl) != VAR_DECL) continue; if (!i) varpool_size++; else create_new_var (var_decl, new_global_vars); } } if (new_global_vars) htab_traverse (new_global_vars, update_varpool_with_new_var, NULL); } /* Dump all new types generated by this optimization. */ static void dump_new_types (void) { d_str str; tree type; unsigned i, j; if (!dump_file) return; fprintf (dump_file, "\nThe following are the new types generated by" " this optimization:\n"); for (i = 0; VEC_iterate (structure, structures, i, str); i++) { if (dump_file) { fprintf (dump_file, "\nFor type "); dump_struct_type (str->decl, 2, 0); fprintf (dump_file, "\nthe number of new types is %d\n", VEC_length (tree, str->new_types)); } for (j = 0; VEC_iterate (tree, str->new_types, j, type); j++) dump_struct_type (type, 2, 0); } } /* This function creates new types to replace old structure types. */ static void create_new_types (void) { d_str str; unsigned i; int str_num = 0; for (i = 0; VEC_iterate (structure, structures, i, str); i++) create_new_type (str, &str_num); } /* Free allocation sites hashtable. */ static void free_alloc_sites (void) { if (alloc_sites) htab_traverse (alloc_sites, free_falloc_sites, NULL); htab_delete (alloc_sites); alloc_sites = NULL; } /* This function collects structures potential for peeling transformation, and inserts them into structures hashtable. */ static void collect_structures (void) { VEC (tree, heap) *unsuitable_types = VEC_alloc (tree, heap, 32); structures = VEC_alloc (structure, heap, 32); /* If program contains user defined mallocs, we give up. */ if (program_redefines_malloc_p ()) return; /* Build data structures hashtable of all data structures in the program. */ build_data_structure (&unsuitable_types); /* This function analyzes whether the form of structure is such that we are capable to transform it. Nested structures are checked here. */ analyze_struct_form (&unsuitable_types); /* This function excludes those structure types that escape compilation unit. */ exclude_escaping_types (&unsuitable_types); /* We do not want to change data layout of the structures with bitfields. */ exclude_types_with_bit_fields (&unsuitable_types); remove_unsuitable_types (unsuitable_types); VEC_free (tree, heap, unsuitable_types); } /* Collect structure allocation sites. In case of arrays we have nothing to do. */ static void collect_allocation_sites (void) { alloc_sites = htab_create (32, malloc_hash, malloc_eq, NULL); collect_alloc_sites (); } /* This function collects data accesses for the structures to be transformed. For each structure field it updates the count field in field_entry. */ static void collect_data_accesses (void) { struct cgraph_node *c_node; for (c_node = cgraph_nodes; c_node; c_node = c_node->next) { enum availability avail = cgraph_function_body_availability (c_node); if (avail == AVAIL_LOCAL || avail == AVAIL_AVAILABLE) { struct function *func = DECL_STRUCT_FUNCTION (c_node->decl); if (!c_node->next_clone) collect_accesses_in_func (func); exclude_alloc_and_field_accs (c_node); } } check_cond_exprs (); /* Print collected accesses. */ dump_accesses (); } /* We do not bother to transform cold structures. Coldness of the structure is defined relatively to the highest structure count among the structures to be transformed. It's triggered by the compiler parameter --param struct-reorg-cold-struct-ratio= where ranges from 0 to 100. Structures with count ratios that are less than this parameter are considered to be cold. */ static void exclude_cold_structs (void) { gcov_type hottest = 0; unsigned i; d_str str; /* We summarize counts of fields of a structure into the structure count. */ for (i = 0; VEC_iterate (structure, structures, i, str); i++) sum_counts (str, &hottest); /* Remove cold structures from structures vector. */ i = 0; while (VEC_iterate (structure, structures, i, str)) if (str->count * 100 < (hottest * STRUCT_REORG_COLD_STRUCT_RATIO)) { if (dump_file) { fprintf (dump_file, "\nThe structure "); print_generic_expr (dump_file, str->decl, 0); fprintf (dump_file, " is cold."); } remove_structure (i); } else i++; } /* This function decomposes original structure into substructures, i.e.clusters. */ static void peel_structs (void) { d_str str; unsigned i; for (i = 0; VEC_iterate (structure, structures, i, str); i++) peel_hot_fields (str); } /* Stage 3. */ /* Do the actual transformation for each structure from the structures hashtable. */ static void do_reorg (void) { /* Check that there is a work to do. */ if (!VEC_length (structure, structures)) { if (dump_file) fprintf (dump_file, "\nNo structures to transform. Exiting..."); return; } else { if (dump_file) { fprintf (dump_file, "\nNumber of structures to transform is %d", VEC_length (structure, structures)); } } /* Generate new types. */ create_new_types (); dump_new_types (); /* Create new global variables. */ create_new_global_vars (); dump_new_vars (new_global_vars); /* Decompose structures for each function separately. */ do_reorg_1 (); /* Free auxiliary data collected for global variables. */ free_new_vars_htab (new_global_vars); } /* Free all auxiliary data used by this optimization. */ static void free_data_structs (void) { free_structures (); free_alloc_sites (); } /* Perform structure decomposition (peeling). */ static void reorg_structs (void) { /* Stage1. */ /* Collect structure types. */ collect_structures (); /* Collect structure allocation sites. */ collect_allocation_sites (); /* Collect structure accesses. */ collect_data_accesses (); /* We transform only hot structures. */ exclude_cold_structs (); /* Stage2. */ /* Decompose structures into substructures, i.e. clusters. */ peel_structs (); /* Stage3. */ /* Do the actual transformation for each structure from the structures hashtable. */ do_reorg (); /* Free all auxiliary data used by this optimization. */ free_data_structs (); } /* Struct-reorg optimization entry point function. */ static unsigned int reorg_structs_drive (void) { reorg_structs (); return 0; } /* Struct-reorg optimization gate function. */ static bool struct_reorg_gate (void) { return flag_ipa_struct_reorg && flag_whole_program && (optimize > 0); } struct simple_ipa_opt_pass pass_ipa_struct_reorg = { { SIMPLE_IPA_PASS, "ipa_struct_reorg", /* name */ struct_reorg_gate, /* gate */ reorg_structs_drive, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_INTEGRATION, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ TODO_verify_ssa, /* todo_flags_start */ TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */ } };