/* Interprocedural analyses. Copyright (C) 2005-2015 Free Software Foundation, Inc. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #ifndef IPA_PROP_H #define IPA_PROP_H /* The following definitions and interfaces are used by interprocedural analyses or parameters. */ #define IPA_UNDESCRIBED_USE -1 /* ipa-prop.c stuff (ipa-cp, indirect inlining): */ /* A jump function for a callsite represents the values passed as actual arguments of the callsite. They were originally proposed in a paper called "Interprocedural Constant Propagation", by David Callahan, Keith D Cooper, Ken Kennedy, Linda Torczon in Comp86, pg 152-161. There are three main types of values : Pass-through - the caller's formal parameter is passed as an actual argument, possibly one simple operation performed on it. Constant - a constant (is_gimple_ip_invariant)is passed as an actual argument. Unknown - neither of the above. IPA_JF_ANCESTOR is a special pass-through jump function, which means that the result is an address of a part of the object pointed to by the formal parameter to which the function refers. It is mainly intended to represent getting addresses of of ancestor fields in C++ (e.g. &this_1(D)->D.1766.D.1756). Note that if the original pointer is NULL, ancestor jump function must behave like a simple pass-through. Other pass-through functions can either simply pass on an unchanged formal parameter or can apply one simple binary operation to it (such jump functions are called polynomial). Jump functions are computed in ipa-prop.c by function update_call_notes_after_inlining. Some information can be lost and jump functions degraded accordingly when inlining, see update_call_notes_after_inlining in the same file. */ enum jump_func_type { IPA_JF_UNKNOWN = 0, /* newly allocated and zeroed jump functions default */ IPA_JF_CONST, /* represented by field costant */ IPA_JF_PASS_THROUGH, /* represented by field pass_through */ IPA_JF_ANCESTOR /* represented by field ancestor */ }; struct ipa_cst_ref_desc; /* Structure holding data required to describe a constant jump function. */ struct GTY(()) ipa_constant_data { /* THe value of the constant. */ tree value; /* Pointer to the structure that describes the reference. */ struct ipa_cst_ref_desc GTY((skip)) *rdesc; }; /* Structure holding data required to describe a pass-through jump function. */ struct GTY(()) ipa_pass_through_data { /* If an operation is to be performed on the original parameter, this is the second (constant) operand. */ tree operand; /* Number of the caller's formal parameter being passed. */ int formal_id; /* Operation that is performed on the argument before it is passed on. NOP_EXPR means no operation. Otherwise oper must be a simple binary arithmetic operation where the caller's parameter is the first operand and operand field from this structure is the second one. */ enum tree_code operation; /* When the passed value is a pointer, it is set to true only when we are certain that no write to the object it points to has occurred since the caller functions started execution, except for changes noted in the aggregate part of the jump function (see description of ipa_agg_jump_function). The flag is used only when the operation is NOP_EXPR. */ unsigned agg_preserved : 1; }; /* Structure holding data required to describe an ancestor pass-through jump function. */ struct GTY(()) ipa_ancestor_jf_data { /* Offset of the field representing the ancestor. */ HOST_WIDE_INT offset; /* Number of the caller's formal parameter being passed. */ int formal_id; /* Flag with the same meaning like agg_preserve in ipa_pass_through_data. */ unsigned agg_preserved : 1; }; /* An element in an aggegate part of a jump function describing a known value at a given offset. When it is part of a pass-through jump function with agg_preserved set or an ancestor jump function with agg_preserved set, all unlisted positions are assumed to be preserved but the value can be a type node, which means that the particular piece (starting at offset and having the size of the type) is clobbered with an unknown value. When agg_preserved is false or the type of the containing jump function is different, all unlisted parts are assumed to be unknown and all values must fulfill is_gimple_ip_invariant. */ struct GTY(()) ipa_agg_jf_item { /* The offset at which the known value is located within the aggregate. */ HOST_WIDE_INT offset; /* The known constant or type if this is a clobber. */ tree value; }; /* Aggregate jump function - i.e. description of contents of aggregates passed either by reference or value. */ struct GTY(()) ipa_agg_jump_function { /* Description of the individual items. */ vec *items; /* True if the data was passed by reference (as opposed to by value). */ bool by_ref; }; typedef struct ipa_agg_jump_function *ipa_agg_jump_function_p; /* Info about pointer alignments. */ struct GTY(()) ipa_alignment { /* The data fields below are valid only if known is true. */ bool known; /* See ptr_info_def and get_pointer_alignment_1 for description of these two. */ unsigned align; unsigned misalign; }; /* A jump function for a callsite represents the values passed as actual arguments of the callsite. See enum jump_func_type for the various types of jump functions supported. */ struct GTY (()) ipa_jump_func { /* Aggregate contants description. See struct ipa_agg_jump_function and its description. */ struct ipa_agg_jump_function agg; /* Information about alignment of pointers. */ struct ipa_alignment alignment; enum jump_func_type type; /* Represents a value of a jump function. pass_through is used only in jump function context. constant represents the actual constant in constant jump functions and member_cst holds constant c++ member functions. */ union jump_func_value { struct ipa_constant_data GTY ((tag ("IPA_JF_CONST"))) constant; struct ipa_pass_through_data GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through; struct ipa_ancestor_jf_data GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor; } GTY ((desc ("%1.type"))) value; }; /* Return the constant stored in a constant jump functin JFUNC. */ static inline tree ipa_get_jf_constant (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_CONST); return jfunc->value.constant.value; } static inline struct ipa_cst_ref_desc * ipa_get_jf_constant_rdesc (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_CONST); return jfunc->value.constant.rdesc; } /* Return the operand of a pass through jmp function JFUNC. */ static inline tree ipa_get_jf_pass_through_operand (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH); return jfunc->value.pass_through.operand; } /* Return the number of the caller's formal parameter that a pass through jump function JFUNC refers to. */ static inline int ipa_get_jf_pass_through_formal_id (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH); return jfunc->value.pass_through.formal_id; } /* Return operation of a pass through jump function JFUNC. */ static inline enum tree_code ipa_get_jf_pass_through_operation (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH); return jfunc->value.pass_through.operation; } /* Return the agg_preserved flag of a pass through jump function JFUNC. */ static inline bool ipa_get_jf_pass_through_agg_preserved (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH); return jfunc->value.pass_through.agg_preserved; } /* Return true if pass through jump function JFUNC preserves type information. */ static inline bool ipa_get_jf_pass_through_type_preserved (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH); return jfunc->value.pass_through.agg_preserved; } /* Return the offset of an ancestor jump function JFUNC. */ static inline HOST_WIDE_INT ipa_get_jf_ancestor_offset (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR); return jfunc->value.ancestor.offset; } /* Return the number of the caller's formal parameter that an ancestor jump function JFUNC refers to. */ static inline int ipa_get_jf_ancestor_formal_id (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR); return jfunc->value.ancestor.formal_id; } /* Return the agg_preserved flag of an ancestor jump function JFUNC. */ static inline bool ipa_get_jf_ancestor_agg_preserved (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR); return jfunc->value.ancestor.agg_preserved; } /* Return true if ancestor jump function JFUNC presrves type information. */ static inline bool ipa_get_jf_ancestor_type_preserved (struct ipa_jump_func *jfunc) { gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR); return jfunc->value.ancestor.agg_preserved; } /* Summary describing a single formal parameter. */ struct ipa_param_descriptor { /* PARAM_DECL of this parameter. */ tree decl; /* If all uses of the parameter are described by ipa-prop structures, this says how many there are. If any use could not be described by means of ipa-prop structures, this is IPA_UNDESCRIBED_USE. */ int controlled_uses; unsigned int move_cost : 31; /* The parameter is used. */ unsigned used : 1; }; /* ipa_node_params stores information related to formal parameters of functions and some other information for interprocedural passes that operate on parameters (such as ipa-cp). */ struct ipa_node_params { ~ipa_node_params (); /* Information about individual formal parameters that are gathered when summaries are generated. */ vec descriptors; /* Pointer to an array of structures describing individual formal parameters. */ struct ipcp_param_lattices *lattices; /* Only for versioned nodes this field would not be NULL, it points to the node that IPA cp cloned from. */ struct cgraph_node *ipcp_orig_node; /* If this node is an ipa-cp clone, these are the known constants that describe what it has been specialized for. */ vec known_csts; /* If this node is an ipa-cp clone, these are the known polymorphic contexts that describe what it has been specialized for. */ vec known_contexts; /* Whether the param uses analysis and jump function computation has already been performed. */ unsigned analysis_done : 1; /* Whether the function is enqueued in ipa-cp propagation stack. */ unsigned node_enqueued : 1; /* Whether we should create a specialized version based on values that are known to be constant in all contexts. */ unsigned do_clone_for_all_contexts : 1; /* Set if this is an IPA-CP clone for all contexts. */ unsigned is_all_contexts_clone : 1; /* Node has been completely replaced by clones and will be removed after ipa-cp is finished. */ unsigned node_dead : 1; /* Node is involved in a recursion, potentionally indirect. */ unsigned node_within_scc : 1; /* Node is calling a private function called only once. */ unsigned node_calling_single_call : 1; }; /* Intermediate information that we get from alias analysis about a particular parameter in a particular basic_block. When a parameter or the memory it references is marked modified, we use that information in all dominated blocks without consulting alias analysis oracle. */ struct ipa_param_aa_status { /* Set when this structure contains meaningful information. If not, the structure describing a dominating BB should be used instead. */ bool valid; /* Whether we have seen something which might have modified the data in question. PARM is for the parameter itself, REF is for data it points to but using the alias type of individual accesses and PT is the same thing but for computing aggregate pass-through functions using a very inclusive ao_ref. */ bool parm_modified, ref_modified, pt_modified; }; /* Information related to a given BB that used only when looking at function body. */ struct ipa_bb_info { /* Call graph edges going out of this BB. */ vec cg_edges; /* Alias analysis statuses of each formal parameter at this bb. */ vec param_aa_statuses; }; /* Structure with global information that is only used when looking at function body. */ struct ipa_func_body_info { /* The node that is being analyzed. */ cgraph_node *node; /* Its info. */ struct ipa_node_params *info; /* Information about individual BBs. */ vec bb_infos; /* Number of parameters. */ int param_count; /* Number of statements already walked by when analyzing this function. */ unsigned int aa_walked; }; /* ipa_node_params access functions. Please use these to access fields that are or will be shared among various passes. */ /* Return the number of formal parameters. */ static inline int ipa_get_param_count (struct ipa_node_params *info) { return info->descriptors.length (); } /* Return the declaration of Ith formal parameter of the function corresponding to INFO. Note there is no setter function as this array is built just once using ipa_initialize_node_params. */ static inline tree ipa_get_param (struct ipa_node_params *info, int i) { gcc_checking_assert (!flag_wpa); return info->descriptors[i].decl; } /* Return the move cost of Ith formal parameter of the function corresponding to INFO. */ static inline int ipa_get_param_move_cost (struct ipa_node_params *info, int i) { return info->descriptors[i].move_cost; } /* Set the used flag corresponding to the Ith formal parameter of the function associated with INFO to VAL. */ static inline void ipa_set_param_used (struct ipa_node_params *info, int i, bool val) { info->descriptors[i].used = val; } /* Return how many uses described by ipa-prop a parameter has or IPA_UNDESCRIBED_USE if there is a use that is not described by these structures. */ static inline int ipa_get_controlled_uses (struct ipa_node_params *info, int i) { /* FIXME: introducing speuclation causes out of bounds access here. */ if (info->descriptors.length () > (unsigned)i) return info->descriptors[i].controlled_uses; return IPA_UNDESCRIBED_USE; } /* Set the controlled counter of a given parameter. */ static inline void ipa_set_controlled_uses (struct ipa_node_params *info, int i, int val) { info->descriptors[i].controlled_uses = val; } /* Return the used flag corresponding to the Ith formal parameter of the function associated with INFO. */ static inline bool ipa_is_param_used (struct ipa_node_params *info, int i) { return info->descriptors[i].used; } /* Information about replacements done in aggregates for a given node (each node has its linked list). */ struct GTY(()) ipa_agg_replacement_value { /* Next item in the linked list. */ struct ipa_agg_replacement_value *next; /* Offset within the aggregate. */ HOST_WIDE_INT offset; /* The constant value. */ tree value; /* The paramter index. */ int index; /* Whether the value was passed by reference. */ bool by_ref; }; /* Structure holding information for the transformation phase of IPA-CP. */ struct GTY(()) ipcp_transformation_summary { /* Linked list of known aggregate values. */ ipa_agg_replacement_value *agg_values; /* Alignment information for pointers. */ vec *alignments; }; void ipa_set_node_agg_value_chain (struct cgraph_node *node, struct ipa_agg_replacement_value *aggvals); void ipcp_grow_transformations_if_necessary (void); /* ipa_edge_args stores information related to a callsite and particularly its arguments. It can be accessed by the IPA_EDGE_REF macro. */ struct GTY(()) ipa_edge_args { /* Vector of the callsite's jump function of each parameter. */ vec *jump_functions; vec *polymorphic_call_contexts; }; /* ipa_edge_args access functions. Please use these to access fields that are or will be shared among various passes. */ /* Return the number of actual arguments. */ static inline int ipa_get_cs_argument_count (struct ipa_edge_args *args) { return vec_safe_length (args->jump_functions); } /* Returns a pointer to the jump function for the ith argument. Please note there is no setter function as jump functions are all set up in ipa_compute_jump_functions. */ static inline struct ipa_jump_func * ipa_get_ith_jump_func (struct ipa_edge_args *args, int i) { return &(*args->jump_functions)[i]; } /* Returns a pointer to the polymorphic call context for the ith argument. NULL if contexts are not computed. */ static inline struct ipa_polymorphic_call_context * ipa_get_ith_polymorhic_call_context (struct ipa_edge_args *args, int i) { if (!args->polymorphic_call_contexts) return NULL; return &(*args->polymorphic_call_contexts)[i]; } /* Function summary for ipa_node_params. */ class ipa_node_params_t: public function_summary { public: ipa_node_params_t (symbol_table *table): function_summary (table) { } /* Hook that is called by summary when a node is duplicated. */ virtual void duplicate (cgraph_node *node, cgraph_node *node2, ipa_node_params *data, ipa_node_params *data2); }; /* Function summary where the parameter infos are actually stored. */ extern ipa_node_params_t *ipa_node_params_sum; /* Vector of IPA-CP transformation data for each clone. */ extern GTY(()) vec *ipcp_transformations; /* Vector where the parameter infos are actually stored. */ extern GTY(()) vec *ipa_edge_args_vector; /* Return the associated parameter/argument info corresponding to the given node/edge. */ #define IPA_NODE_REF(NODE) (ipa_node_params_sum->get (NODE)) #define IPA_EDGE_REF(EDGE) (&(*ipa_edge_args_vector)[(EDGE)->uid]) /* This macro checks validity of index returned by ipa_get_param_decl_index function. */ #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1) /* Creating and freeing ipa_node_params and ipa_edge_args. */ void ipa_create_all_node_params (void); void ipa_create_all_edge_args (void); void ipa_free_edge_args_substructures (struct ipa_edge_args *); void ipa_free_all_node_params (void); void ipa_free_all_edge_args (void); void ipa_free_all_structures_after_ipa_cp (void); void ipa_free_all_structures_after_iinln (void); void ipa_register_cgraph_hooks (void); int count_formal_params (tree fndecl); /* This function ensures the array of node param infos is big enough to accommodate a structure for all nodes and reallocates it if not. */ static inline void ipa_check_create_node_params (void) { if (!ipa_node_params_sum) ipa_node_params_sum = new ipa_node_params_t (symtab); } /* This function ensures the array of edge arguments infos is big enough to accommodate a structure for all edges and reallocates it if not. */ static inline void ipa_check_create_edge_args (void) { if (vec_safe_length (ipa_edge_args_vector) <= (unsigned) symtab->edges_max_uid) vec_safe_grow_cleared (ipa_edge_args_vector, symtab->edges_max_uid + 1); } /* Returns true if the array of edge infos is large enough to accommodate an info for EDGE. The main purpose of this function is that debug dumping function can check info availability without causing reallocations. */ static inline bool ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge) { return ((unsigned) edge->uid < vec_safe_length (ipa_edge_args_vector)); } static inline ipcp_transformation_summary * ipcp_get_transformation_summary (cgraph_node *node) { if ((unsigned) node->uid >= vec_safe_length (ipcp_transformations)) return NULL; return &(*ipcp_transformations)[node->uid]; } /* Return the aggregate replacements for NODE, if there are any. */ static inline struct ipa_agg_replacement_value * ipa_get_agg_replacements_for_node (cgraph_node *node) { ipcp_transformation_summary *ts = ipcp_get_transformation_summary (node); return ts ? ts->agg_values : NULL; } /* Function formal parameters related computations. */ void ipa_initialize_node_params (struct cgraph_node *node); bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs, vec *new_edges); /* Indirect edge and binfo processing. */ tree ipa_get_indirect_edge_target (struct cgraph_edge *ie, vec , vec, vec, bool *); struct cgraph_edge *ipa_make_edge_direct_to_target (struct cgraph_edge *, tree, bool speculative = false); tree ipa_impossible_devirt_target (struct cgraph_edge *, tree); /* Functions related to both. */ void ipa_analyze_node (struct cgraph_node *); /* Aggregate jump function related functions. */ tree ipa_find_agg_cst_for_param (struct ipa_agg_jump_function *, HOST_WIDE_INT, bool); bool ipa_load_from_parm_agg (struct ipa_func_body_info *, vec, gimple, tree, int *, HOST_WIDE_INT *, HOST_WIDE_INT *, bool *); /* Debugging interface. */ void ipa_print_node_params (FILE *, struct cgraph_node *node); void ipa_print_all_params (FILE *); void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node); void ipa_print_all_jump_functions (FILE * f); void ipcp_verify_propagated_values (void); extern alloc_pool ipcp_cst_values_pool; extern alloc_pool ipcp_poly_ctx_values_pool; extern alloc_pool ipcp_sources_pool; extern alloc_pool ipcp_agg_lattice_pool; /* Operation to be performed for the parameter in ipa_parm_adjustment below. */ enum ipa_parm_op { IPA_PARM_OP_NONE, /* This describes a brand new parameter. The field `type' should be set to the new type, `arg_prefix' should be set to the string prefix for the new DECL_NAME, and `new_decl' will ultimately hold the newly created argument. */ IPA_PARM_OP_NEW, /* This new parameter is an unmodified parameter at index base_index. */ IPA_PARM_OP_COPY, /* This adjustment describes a parameter that is about to be removed completely. Most users will probably need to book keep those so that they don't leave behinfd any non default def ssa names belonging to them. */ IPA_PARM_OP_REMOVE }; /* Structure to describe transformations of formal parameters and actual arguments. Each instance describes one new parameter and they are meant to be stored in a vector. Additionally, most users will probably want to store adjustments about parameters that are being removed altogether so that SSA names belonging to them can be replaced by SSA names of an artificial variable. */ struct ipa_parm_adjustment { /* The original PARM_DECL itself, helpful for processing of the body of the function itself. Intended for traversing function bodies. ipa_modify_formal_parameters, ipa_modify_call_arguments and ipa_combine_adjustments ignore this and use base_index. ipa_modify_formal_parameters actually sets this. */ tree base; /* Type of the new parameter. However, if by_ref is true, the real type will be a pointer to this type. */ tree type; /* Alias refrerence type to be used in MEM_REFs when adjusting caller arguments. */ tree alias_ptr_type; /* The new declaration when creating/replacing a parameter. Created by ipa_modify_formal_parameters, useful for functions modifying the body accordingly. For brand new arguments, this is the newly created argument. */ tree new_decl; /* New declaration of a substitute variable that we may use to replace all non-default-def ssa names when a parm decl is going away. */ tree new_ssa_base; /* If non-NULL and the original parameter is to be removed (copy_param below is NULL), this is going to be its nonlocalized vars value. */ tree nonlocal_value; /* This holds the prefix to be used for the new DECL_NAME. */ const char *arg_prefix; /* Offset into the original parameter (for the cases when the new parameter is a component of an original one). */ HOST_WIDE_INT offset; /* Zero based index of the original parameter this one is based on. */ int base_index; /* Whether this parameter is a new parameter, a copy of an old one, or one about to be removed. */ enum ipa_parm_op op; /* The parameter is to be passed by reference. */ unsigned by_ref : 1; }; typedef vec ipa_parm_adjustment_vec; vec ipa_get_vector_of_formal_parms (tree fndecl); vec ipa_get_vector_of_formal_parm_types (tree fntype); void ipa_modify_formal_parameters (tree fndecl, ipa_parm_adjustment_vec); void ipa_modify_call_arguments (struct cgraph_edge *, gcall *, ipa_parm_adjustment_vec); ipa_parm_adjustment_vec ipa_combine_adjustments (ipa_parm_adjustment_vec, ipa_parm_adjustment_vec); void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec, tree); void ipa_dump_agg_replacement_values (FILE *f, struct ipa_agg_replacement_value *av); void ipa_prop_write_jump_functions (void); void ipa_prop_read_jump_functions (void); void ipcp_write_transformation_summaries (void); void ipcp_read_transformation_summaries (void); void ipa_update_after_lto_read (void); int ipa_get_param_decl_index (struct ipa_node_params *, tree); tree ipa_value_from_jfunc (struct ipa_node_params *info, struct ipa_jump_func *jfunc); unsigned int ipcp_transform_function (struct cgraph_node *node); ipa_polymorphic_call_context ipa_context_from_jfunc (ipa_node_params *, cgraph_edge *, int, ipa_jump_func *); void ipa_dump_param (FILE *, struct ipa_node_params *info, int i); bool ipa_modify_expr (tree *, bool, ipa_parm_adjustment_vec); ipa_parm_adjustment *ipa_get_adjustment_candidate (tree **, bool *, ipa_parm_adjustment_vec, bool); /* From tree-sra.c: */ tree build_ref_for_offset (location_t, tree, HOST_WIDE_INT, tree, gimple_stmt_iterator *, bool); /* In ipa-cp.c */ void ipa_cp_c_finalize (void); #endif /* IPA_PROP_H */