/* Interprocedural constant propagation Copyright (C) 2005-2015 Free Software Foundation, Inc. Contributed by Razya Ladelsky and Martin Jambor 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 . */ /* Interprocedural constant propagation (IPA-CP). The goal of this transformation is to 1) discover functions which are always invoked with some arguments with the same known constant values and modify the functions so that the subsequent optimizations can take advantage of the knowledge, and 2) partial specialization - create specialized versions of functions transformed in this way if some parameters are known constants only in certain contexts but the estimated tradeoff between speedup and cost size is deemed good. The algorithm also propagates types and attempts to perform type based devirtualization. Types are propagated much like constants. The algorithm basically consists of three stages. In the first, functions are analyzed one at a time and jump functions are constructed for all known call-sites. In the second phase, the pass propagates information from the jump functions across the call to reveal what values are available at what call sites, performs estimations of effects of known values on functions and their callees, and finally decides what specialized extra versions should be created. In the third, the special versions materialize and appropriate calls are redirected. The algorithm used is to a certain extent based on "Interprocedural Constant Propagation", by David Callahan, Keith D Cooper, Ken Kennedy, Linda Torczon, Comp86, pg 152-161 and "A Methodology for Procedure Cloning" by Keith D Cooper, Mary W. Hall, and Ken Kennedy. First stage - intraprocedural analysis ======================================= This phase computes jump_function and modification flags. A jump function for a call-site represents the values passed as an actual arguments of a given call-site. In principle, there are three types of values: Pass through - the caller's formal parameter is passed as an actual argument, plus an operation on it can be performed. Constant - a constant is passed as an actual argument. Unknown - neither of the above. All jump function types are described in detail in ipa-prop.h, together with the data structures that represent them and methods of accessing them. ipcp_generate_summary() is the main function of the first stage. Second stage - interprocedural analysis ======================================== This stage is itself divided into two phases. In the first, we propagate known values over the call graph, in the second, we make cloning decisions. It uses a different algorithm than the original Callahan's paper. First, we traverse the functions topologically from callers to callees and, for each strongly connected component (SCC), we propagate constants according to previously computed jump functions. We also record what known values depend on other known values and estimate local effects. Finally, we propagate cumulative information about these effects from dependent values to those on which they depend. Second, we again traverse the call graph in the same topological order and make clones for functions which we know are called with the same values in all contexts and decide about extra specialized clones of functions just for some contexts - these decisions are based on both local estimates and cumulative estimates propagated from callees. ipcp_propagate_stage() and ipcp_decision_stage() together constitute the third stage. Third phase - materialization of clones, call statement updates. ============================================ This stage is currently performed by call graph code (mainly in cgraphunit.c and tree-inline.c) according to instructions inserted to the call graph by the second stage. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "hash-set.h" #include "machmode.h" #include "vec.h" #include "hash-map.h" #include "double-int.h" #include "input.h" #include "alias.h" #include "symtab.h" #include "options.h" #include "wide-int.h" #include "inchash.h" #include "tree.h" #include "fold-const.h" #include "gimple-fold.h" #include "gimple-expr.h" #include "target.h" #include "predict.h" #include "basic-block.h" #include "is-a.h" #include "plugin-api.h" #include "tm.h" #include "hard-reg-set.h" #include "input.h" #include "function.h" #include "ipa-ref.h" #include "cgraph.h" #include "alloc-pool.h" #include "symbol-summary.h" #include "ipa-prop.h" #include "bitmap.h" #include "tree-pass.h" #include "flags.h" #include "diagnostic.h" #include "tree-pretty-print.h" #include "tree-inline.h" #include "params.h" #include "ipa-inline.h" #include "ipa-utils.h" template class ipcp_value; /* Describes a particular source for an IPA-CP value. */ template class ipcp_value_source { public: /* Aggregate offset of the source, negative if the source is scalar value of the argument itself. */ HOST_WIDE_INT offset; /* The incoming edge that brought the value. */ cgraph_edge *cs; /* If the jump function that resulted into his value was a pass-through or an ancestor, this is the ipcp_value of the caller from which the described value has been derived. Otherwise it is NULL. */ ipcp_value *val; /* Next pointer in a linked list of sources of a value. */ ipcp_value_source *next; /* If the jump function that resulted into his value was a pass-through or an ancestor, this is the index of the parameter of the caller the jump function references. */ int index; }; /* Common ancestor for all ipcp_value instantiations. */ class ipcp_value_base { public: /* Time benefit and size cost that specializing the function for this value would bring about in this function alone. */ int local_time_benefit, local_size_cost; /* Time benefit and size cost that specializing the function for this value can bring about in it's callees (transitively). */ int prop_time_benefit, prop_size_cost; }; /* Describes one particular value stored in struct ipcp_lattice. */ template class ipcp_value : public ipcp_value_base { public: /* The actual value for the given parameter. */ valtype value; /* The list of sources from which this value originates. */ ipcp_value_source *sources; /* Next pointers in a linked list of all values in a lattice. */ ipcp_value *next; /* Next pointers in a linked list of values in a strongly connected component of values. */ ipcp_value *scc_next; /* Next pointers in a linked list of SCCs of values sorted topologically according their sources. */ ipcp_value *topo_next; /* A specialized node created for this value, NULL if none has been (so far) created. */ cgraph_node *spec_node; /* Depth first search number and low link for topological sorting of values. */ int dfs, low_link; /* True if this valye is currently on the topo-sort stack. */ bool on_stack; void add_source (cgraph_edge *cs, ipcp_value *src_val, int src_idx, HOST_WIDE_INT offset); }; /* Lattice describing potential values of a formal parameter of a function, or a part of an aggreagate. TOP is represented by a lattice with zero values and with contains_variable and bottom flags cleared. BOTTOM is represented by a lattice with the bottom flag set. In that case, values and contains_variable flag should be disregarded. */ template class ipcp_lattice { public: /* The list of known values and types in this lattice. Note that values are not deallocated if a lattice is set to bottom because there may be value sources referencing them. */ ipcp_value *values; /* Number of known values and types in this lattice. */ int values_count; /* The lattice contains a variable component (in addition to values). */ bool contains_variable; /* The value of the lattice is bottom (i.e. variable and unusable for any propagation). */ bool bottom; inline bool is_single_const (); inline bool set_to_bottom (); inline bool set_contains_variable (); bool add_value (valtype newval, cgraph_edge *cs, ipcp_value *src_val = NULL, int src_idx = 0, HOST_WIDE_INT offset = -1); void print (FILE * f, bool dump_sources, bool dump_benefits); }; /* Lattice of tree values with an offset to describe a part of an aggregate. */ class ipcp_agg_lattice : public ipcp_lattice { public: /* Offset that is being described by this lattice. */ HOST_WIDE_INT offset; /* Size so that we don't have to re-compute it every time we traverse the list. Must correspond to TYPE_SIZE of all lat values. */ HOST_WIDE_INT size; /* Next element of the linked list. */ struct ipcp_agg_lattice *next; }; /* Structure containing lattices for a parameter itself and for pieces of aggregates that are passed in the parameter or by a reference in a parameter plus some other useful flags. */ class ipcp_param_lattices { public: /* Lattice describing the value of the parameter itself. */ ipcp_lattice itself; /* Lattice describing the the polymorphic contexts of a parameter. */ ipcp_lattice ctxlat; /* Lattices describing aggregate parts. */ ipcp_agg_lattice *aggs; /* Alignment information. Very basic one value lattice where !known means TOP and zero alignment bottom. */ ipa_alignment alignment; /* Number of aggregate lattices */ int aggs_count; /* True if aggregate data were passed by reference (as opposed to by value). */ bool aggs_by_ref; /* All aggregate lattices contain a variable component (in addition to values). */ bool aggs_contain_variable; /* The value of all aggregate lattices is bottom (i.e. variable and unusable for any propagation). */ bool aggs_bottom; /* There is a virtual call based on this parameter. */ bool virt_call; }; /* Allocation pools for values and their sources in ipa-cp. */ alloc_pool ipcp_cst_values_pool; alloc_pool ipcp_poly_ctx_values_pool; alloc_pool ipcp_sources_pool; alloc_pool ipcp_agg_lattice_pool; /* Maximal count found in program. */ static gcov_type max_count; /* Original overall size of the program. */ static long overall_size, max_new_size; /* Return the param lattices structure corresponding to the Ith formal parameter of the function described by INFO. */ static inline struct ipcp_param_lattices * ipa_get_parm_lattices (struct ipa_node_params *info, int i) { gcc_assert (i >= 0 && i < ipa_get_param_count (info)); gcc_checking_assert (!info->ipcp_orig_node); gcc_checking_assert (info->lattices); return &(info->lattices[i]); } /* Return the lattice corresponding to the scalar value of the Ith formal parameter of the function described by INFO. */ static inline ipcp_lattice * ipa_get_scalar_lat (struct ipa_node_params *info, int i) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); return &plats->itself; } /* Return the lattice corresponding to the scalar value of the Ith formal parameter of the function described by INFO. */ static inline ipcp_lattice * ipa_get_poly_ctx_lat (struct ipa_node_params *info, int i) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); return &plats->ctxlat; } /* Return whether LAT is a lattice with a single constant and without an undefined value. */ template inline bool ipcp_lattice::is_single_const () { if (bottom || contains_variable || values_count != 1) return false; else return true; } /* Print V which is extracted from a value in a lattice to F. */ static void print_ipcp_constant_value (FILE * f, tree v) { if (TREE_CODE (v) == ADDR_EXPR && TREE_CODE (TREE_OPERAND (v, 0)) == CONST_DECL) { fprintf (f, "& "); print_generic_expr (f, DECL_INITIAL (TREE_OPERAND (v, 0)), 0); } else print_generic_expr (f, v, 0); } /* Print V which is extracted from a value in a lattice to F. */ static void print_ipcp_constant_value (FILE * f, ipa_polymorphic_call_context v) { v.dump(f, false); } /* Print a lattice LAT to F. */ template void ipcp_lattice::print (FILE * f, bool dump_sources, bool dump_benefits) { ipcp_value *val; bool prev = false; if (bottom) { fprintf (f, "BOTTOM\n"); return; } if (!values_count && !contains_variable) { fprintf (f, "TOP\n"); return; } if (contains_variable) { fprintf (f, "VARIABLE"); prev = true; if (dump_benefits) fprintf (f, "\n"); } for (val = values; val; val = val->next) { if (dump_benefits && prev) fprintf (f, " "); else if (!dump_benefits && prev) fprintf (f, ", "); else prev = true; print_ipcp_constant_value (f, val->value); if (dump_sources) { ipcp_value_source *s; fprintf (f, " [from:"); for (s = val->sources; s; s = s->next) fprintf (f, " %i(%i)", s->cs->caller->order, s->cs->frequency); fprintf (f, "]"); } if (dump_benefits) fprintf (f, " [loc_time: %i, loc_size: %i, " "prop_time: %i, prop_size: %i]\n", val->local_time_benefit, val->local_size_cost, val->prop_time_benefit, val->prop_size_cost); } if (!dump_benefits) fprintf (f, "\n"); } /* Print all ipcp_lattices of all functions to F. */ static void print_all_lattices (FILE * f, bool dump_sources, bool dump_benefits) { struct cgraph_node *node; int i, count; fprintf (f, "\nLattices:\n"); FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) { struct ipa_node_params *info; info = IPA_NODE_REF (node); fprintf (f, " Node: %s/%i:\n", node->name (), node->order); count = ipa_get_param_count (info); for (i = 0; i < count; i++) { struct ipcp_agg_lattice *aglat; struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); fprintf (f, " param [%d]: ", i); plats->itself.print (f, dump_sources, dump_benefits); fprintf (f, " ctxs: "); plats->ctxlat.print (f, dump_sources, dump_benefits); if (plats->alignment.known && plats->alignment.align > 0) fprintf (f, " Alignment %u, misalignment %u\n", plats->alignment.align, plats->alignment.misalign); else if (plats->alignment.known) fprintf (f, " Alignment unusable\n"); else fprintf (f, " Alignment unknown\n"); if (plats->virt_call) fprintf (f, " virt_call flag set\n"); if (plats->aggs_bottom) { fprintf (f, " AGGS BOTTOM\n"); continue; } if (plats->aggs_contain_variable) fprintf (f, " AGGS VARIABLE\n"); for (aglat = plats->aggs; aglat; aglat = aglat->next) { fprintf (f, " %soffset " HOST_WIDE_INT_PRINT_DEC ": ", plats->aggs_by_ref ? "ref " : "", aglat->offset); aglat->print (f, dump_sources, dump_benefits); } } } } /* Determine whether it is at all technically possible to create clones of NODE and store this information in the ipa_node_params structure associated with NODE. */ static void determine_versionability (struct cgraph_node *node) { const char *reason = NULL; /* There are a number of generic reasons functions cannot be versioned. We also cannot remove parameters if there are type attributes such as fnspec present. */ if (node->alias || node->thunk.thunk_p) reason = "alias or thunk"; else if (!node->local.versionable) reason = "not a tree_versionable_function"; else if (node->get_availability () <= AVAIL_INTERPOSABLE) reason = "insufficient body availability"; else if (!opt_for_fn (node->decl, optimize) || !opt_for_fn (node->decl, flag_ipa_cp)) reason = "non-optimized function"; else if (lookup_attribute ("omp declare simd", DECL_ATTRIBUTES (node->decl))) { /* Ideally we should clone the SIMD clones themselves and create vector copies of them, so IPA-cp and SIMD clones can happily coexist, but that may not be worth the effort. */ reason = "function has SIMD clones"; } /* Don't clone decls local to a comdat group; it breaks and for C++ decloned constructors, inlining is always better anyway. */ else if (node->comdat_local_p ()) reason = "comdat-local function"; if (reason && dump_file && !node->alias && !node->thunk.thunk_p) fprintf (dump_file, "Function %s/%i is not versionable, reason: %s.\n", node->name (), node->order, reason); node->local.versionable = (reason == NULL); } /* Return true if it is at all technically possible to create clones of a NODE. */ static bool ipcp_versionable_function_p (struct cgraph_node *node) { return node->local.versionable; } /* Structure holding accumulated information about callers of a node. */ struct caller_statistics { gcov_type count_sum; int n_calls, n_hot_calls, freq_sum; }; /* Initialize fields of STAT to zeroes. */ static inline void init_caller_stats (struct caller_statistics *stats) { stats->count_sum = 0; stats->n_calls = 0; stats->n_hot_calls = 0; stats->freq_sum = 0; } /* Worker callback of cgraph_for_node_and_aliases accumulating statistics of non-thunk incoming edges to NODE. */ static bool gather_caller_stats (struct cgraph_node *node, void *data) { struct caller_statistics *stats = (struct caller_statistics *) data; struct cgraph_edge *cs; for (cs = node->callers; cs; cs = cs->next_caller) if (cs->caller->thunk.thunk_p) cs->caller->call_for_symbol_thunks_and_aliases (gather_caller_stats, stats, false); else { stats->count_sum += cs->count; stats->freq_sum += cs->frequency; stats->n_calls++; if (cs->maybe_hot_p ()) stats->n_hot_calls ++; } return false; } /* Return true if this NODE is viable candidate for cloning. */ static bool ipcp_cloning_candidate_p (struct cgraph_node *node) { struct caller_statistics stats; gcc_checking_assert (node->has_gimple_body_p ()); if (!opt_for_fn (node->decl, flag_ipa_cp_clone)) { if (dump_file) fprintf (dump_file, "Not considering %s for cloning; " "-fipa-cp-clone disabled.\n", node->name ()); return false; } if (!optimize_function_for_speed_p (DECL_STRUCT_FUNCTION (node->decl))) { if (dump_file) fprintf (dump_file, "Not considering %s for cloning; " "optimizing it for size.\n", node->name ()); return false; } init_caller_stats (&stats); node->call_for_symbol_thunks_and_aliases (gather_caller_stats, &stats, false); if (inline_summaries->get (node)->self_size < stats.n_calls) { if (dump_file) fprintf (dump_file, "Considering %s for cloning; code might shrink.\n", node->name ()); return true; } /* When profile is available and function is hot, propagate into it even if calls seems cold; constant propagation can improve function's speed significantly. */ if (max_count) { if (stats.count_sum > node->count * 90 / 100) { if (dump_file) fprintf (dump_file, "Considering %s for cloning; " "usually called directly.\n", node->name ()); return true; } } if (!stats.n_hot_calls) { if (dump_file) fprintf (dump_file, "Not considering %s for cloning; no hot calls.\n", node->name ()); return false; } if (dump_file) fprintf (dump_file, "Considering %s for cloning.\n", node->name ()); return true; } template class value_topo_info { public: /* Head of the linked list of topologically sorted values. */ ipcp_value *values_topo; /* Stack for creating SCCs, represented by a linked list too. */ ipcp_value *stack; /* Counter driving the algorithm in add_val_to_toposort. */ int dfs_counter; value_topo_info () : values_topo (NULL), stack (NULL), dfs_counter (0) {} void add_val (ipcp_value *cur_val); void propagate_effects (); }; /* Arrays representing a topological ordering of call graph nodes and a stack of nodes used during constant propagation and also data required to perform topological sort of values and propagation of benefits in the determined order. */ class ipa_topo_info { public: /* Array with obtained topological order of cgraph nodes. */ struct cgraph_node **order; /* Stack of cgraph nodes used during propagation within SCC until all values in the SCC stabilize. */ struct cgraph_node **stack; int nnodes, stack_top; value_topo_info constants; value_topo_info contexts; ipa_topo_info () : order(NULL), stack(NULL), nnodes(0), stack_top(0), constants () {} }; /* Allocate the arrays in TOPO and topologically sort the nodes into order. */ static void build_toporder_info (struct ipa_topo_info *topo) { topo->order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); topo->stack = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); gcc_checking_assert (topo->stack_top == 0); topo->nnodes = ipa_reduced_postorder (topo->order, true, true, NULL); } /* Free information about strongly connected components and the arrays in TOPO. */ static void free_toporder_info (struct ipa_topo_info *topo) { ipa_free_postorder_info (); free (topo->order); free (topo->stack); } /* Add NODE to the stack in TOPO, unless it is already there. */ static inline void push_node_to_stack (struct ipa_topo_info *topo, struct cgraph_node *node) { struct ipa_node_params *info = IPA_NODE_REF (node); if (info->node_enqueued) return; info->node_enqueued = 1; topo->stack[topo->stack_top++] = node; } /* Pop a node from the stack in TOPO and return it or return NULL if the stack is empty. */ static struct cgraph_node * pop_node_from_stack (struct ipa_topo_info *topo) { if (topo->stack_top) { struct cgraph_node *node; topo->stack_top--; node = topo->stack[topo->stack_top]; IPA_NODE_REF (node)->node_enqueued = 0; return node; } else return NULL; } /* Set lattice LAT to bottom and return true if it previously was not set as such. */ template inline bool ipcp_lattice::set_to_bottom () { bool ret = !bottom; bottom = true; return ret; } /* Mark lattice as containing an unknown value and return true if it previously was not marked as such. */ template inline bool ipcp_lattice::set_contains_variable () { bool ret = !contains_variable; contains_variable = true; return ret; } /* Set all aggegate lattices in PLATS to bottom and return true if they were not previously set as such. */ static inline bool set_agg_lats_to_bottom (struct ipcp_param_lattices *plats) { bool ret = !plats->aggs_bottom; plats->aggs_bottom = true; return ret; } /* Mark all aggegate lattices in PLATS as containing an unknown value and return true if they were not previously marked as such. */ static inline bool set_agg_lats_contain_variable (struct ipcp_param_lattices *plats) { bool ret = !plats->aggs_contain_variable; plats->aggs_contain_variable = true; return ret; } /* Return true if alignment information in PLATS is known to be unusable. */ static inline bool alignment_bottom_p (ipcp_param_lattices *plats) { return plats->alignment.known && (plats->alignment.align == 0); } /* Set alignment information in PLATS to unusable. Return true if it previously was usable or unknown. */ static inline bool set_alignment_to_bottom (ipcp_param_lattices *plats) { if (alignment_bottom_p (plats)) return false; plats->alignment.known = true; plats->alignment.align = 0; return true; } /* Mark bot aggregate and scalar lattices as containing an unknown variable, return true is any of them has not been marked as such so far. */ static inline bool set_all_contains_variable (struct ipcp_param_lattices *plats) { bool ret; ret = plats->itself.set_contains_variable (); ret |= plats->ctxlat.set_contains_variable (); ret |= set_agg_lats_contain_variable (plats); ret |= set_alignment_to_bottom (plats); return ret; } /* Initialize ipcp_lattices. */ static void initialize_node_lattices (struct cgraph_node *node) { struct ipa_node_params *info = IPA_NODE_REF (node); struct cgraph_edge *ie; bool disable = false, variable = false; int i; gcc_checking_assert (node->has_gimple_body_p ()); if (!cgraph_local_p (node)) { /* When cloning is allowed, we can assume that externally visible functions are not called. We will compensate this by cloning later. */ if (ipcp_versionable_function_p (node) && ipcp_cloning_candidate_p (node)) variable = true; else disable = true; } if (disable || variable) { for (i = 0; i < ipa_get_param_count (info) ; i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); if (disable) { plats->itself.set_to_bottom (); plats->ctxlat.set_to_bottom (); set_agg_lats_to_bottom (plats); set_alignment_to_bottom (plats); } else set_all_contains_variable (plats); } if (dump_file && (dump_flags & TDF_DETAILS) && !node->alias && !node->thunk.thunk_p) fprintf (dump_file, "Marking all lattices of %s/%i as %s\n", node->name (), node->order, disable ? "BOTTOM" : "VARIABLE"); } for (ie = node->indirect_calls; ie; ie = ie->next_callee) if (ie->indirect_info->polymorphic && ie->indirect_info->param_index >= 0) { gcc_checking_assert (ie->indirect_info->param_index >= 0); ipa_get_parm_lattices (info, ie->indirect_info->param_index)->virt_call = 1; } } /* Return the result of a (possibly arithmetic) pass through jump function JFUNC on the constant value INPUT. Return NULL_TREE if that cannot be determined or be considered an interprocedural invariant. */ static tree ipa_get_jf_pass_through_result (struct ipa_jump_func *jfunc, tree input) { tree restype, res; gcc_checking_assert (is_gimple_ip_invariant (input)); if (ipa_get_jf_pass_through_operation (jfunc) == NOP_EXPR) return input; if (TREE_CODE_CLASS (ipa_get_jf_pass_through_operation (jfunc)) == tcc_comparison) restype = boolean_type_node; else restype = TREE_TYPE (input); res = fold_binary (ipa_get_jf_pass_through_operation (jfunc), restype, input, ipa_get_jf_pass_through_operand (jfunc)); if (res && !is_gimple_ip_invariant (res)) return NULL_TREE; return res; } /* Return the result of an ancestor jump function JFUNC on the constant value INPUT. Return NULL_TREE if that cannot be determined. */ static tree ipa_get_jf_ancestor_result (struct ipa_jump_func *jfunc, tree input) { gcc_checking_assert (TREE_CODE (input) != TREE_BINFO); if (TREE_CODE (input) == ADDR_EXPR) { tree t = TREE_OPERAND (input, 0); t = build_ref_for_offset (EXPR_LOCATION (t), t, ipa_get_jf_ancestor_offset (jfunc), ptr_type_node, NULL, false); return build_fold_addr_expr (t); } else return NULL_TREE; } /* Determine whether JFUNC evaluates to a single known constant value and if so, return it. Otherwise return NULL. INFO describes the caller node or the one it is inlined to, so that pass-through jump functions can be evaluated. */ tree ipa_value_from_jfunc (struct ipa_node_params *info, struct ipa_jump_func *jfunc) { if (jfunc->type == IPA_JF_CONST) return ipa_get_jf_constant (jfunc); else if (jfunc->type == IPA_JF_PASS_THROUGH || jfunc->type == IPA_JF_ANCESTOR) { tree input; int idx; if (jfunc->type == IPA_JF_PASS_THROUGH) idx = ipa_get_jf_pass_through_formal_id (jfunc); else idx = ipa_get_jf_ancestor_formal_id (jfunc); if (info->ipcp_orig_node) input = info->known_csts[idx]; else { ipcp_lattice *lat; if (!info->lattices) return NULL_TREE; lat = ipa_get_scalar_lat (info, idx); if (!lat->is_single_const ()) return NULL_TREE; input = lat->values->value; } if (!input) return NULL_TREE; if (jfunc->type == IPA_JF_PASS_THROUGH) return ipa_get_jf_pass_through_result (jfunc, input); else return ipa_get_jf_ancestor_result (jfunc, input); } else return NULL_TREE; } /* Determie whether JFUNC evaluates to single known polymorphic context, given that INFO describes the caller node or the one it is inlined to, CS is the call graph edge corresponding to JFUNC and CSIDX index of the described parameter. */ ipa_polymorphic_call_context ipa_context_from_jfunc (ipa_node_params *info, cgraph_edge *cs, int csidx, ipa_jump_func *jfunc) { ipa_edge_args *args = IPA_EDGE_REF (cs); ipa_polymorphic_call_context ctx; ipa_polymorphic_call_context *edge_ctx = cs ? ipa_get_ith_polymorhic_call_context (args, csidx) : NULL; if (edge_ctx && !edge_ctx->useless_p ()) ctx = *edge_ctx; if (jfunc->type == IPA_JF_PASS_THROUGH || jfunc->type == IPA_JF_ANCESTOR) { ipa_polymorphic_call_context srcctx; int srcidx; bool type_preserved = true; if (jfunc->type == IPA_JF_PASS_THROUGH) { if (ipa_get_jf_pass_through_operation (jfunc) != NOP_EXPR) return ctx; type_preserved = ipa_get_jf_pass_through_type_preserved (jfunc); srcidx = ipa_get_jf_pass_through_formal_id (jfunc); } else { type_preserved = ipa_get_jf_ancestor_type_preserved (jfunc); srcidx = ipa_get_jf_ancestor_formal_id (jfunc); } if (info->ipcp_orig_node) { if (info->known_contexts.exists ()) srcctx = info->known_contexts[srcidx]; } else { if (!info->lattices) return ctx; ipcp_lattice *lat; lat = ipa_get_poly_ctx_lat (info, srcidx); if (!lat->is_single_const ()) return ctx; srcctx = lat->values->value; } if (srcctx.useless_p ()) return ctx; if (jfunc->type == IPA_JF_ANCESTOR) srcctx.offset_by (ipa_get_jf_ancestor_offset (jfunc)); if (!type_preserved) srcctx.possible_dynamic_type_change (cs->in_polymorphic_cdtor); srcctx.combine_with (ctx); return srcctx; } return ctx; } /* If checking is enabled, verify that no lattice is in the TOP state, i.e. not bottom, not containing a variable component and without any known value at the same time. */ DEBUG_FUNCTION void ipcp_verify_propagated_values (void) { struct cgraph_node *node; FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) { struct ipa_node_params *info = IPA_NODE_REF (node); int i, count = ipa_get_param_count (info); for (i = 0; i < count; i++) { ipcp_lattice *lat = ipa_get_scalar_lat (info, i); if (!lat->bottom && !lat->contains_variable && lat->values_count == 0) { if (dump_file) { symtab_node::dump_table (dump_file); fprintf (dump_file, "\nIPA lattices after constant " "propagation, before gcc_unreachable:\n"); print_all_lattices (dump_file, true, false); } gcc_unreachable (); } } } } /* Return true iff X and Y should be considered equal values by IPA-CP. */ static bool values_equal_for_ipcp_p (tree x, tree y) { gcc_checking_assert (x != NULL_TREE && y != NULL_TREE); if (x == y) return true; if (TREE_CODE (x) == ADDR_EXPR && TREE_CODE (y) == ADDR_EXPR && TREE_CODE (TREE_OPERAND (x, 0)) == CONST_DECL && TREE_CODE (TREE_OPERAND (y, 0)) == CONST_DECL) return operand_equal_p (DECL_INITIAL (TREE_OPERAND (x, 0)), DECL_INITIAL (TREE_OPERAND (y, 0)), 0); else return operand_equal_p (x, y, 0); } /* Return true iff X and Y should be considered equal contexts by IPA-CP. */ static bool values_equal_for_ipcp_p (ipa_polymorphic_call_context x, ipa_polymorphic_call_context y) { return x.equal_to (y); } /* Add a new value source to the value represented by THIS, marking that a value comes from edge CS and (if the underlying jump function is a pass-through or an ancestor one) from a caller value SRC_VAL of a caller parameter described by SRC_INDEX. OFFSET is negative if the source was the scalar value of the parameter itself or the offset within an aggregate. */ template void ipcp_value::add_source (cgraph_edge *cs, ipcp_value *src_val, int src_idx, HOST_WIDE_INT offset) { ipcp_value_source *src; src = new (pool_alloc (ipcp_sources_pool)) ipcp_value_source; src->offset = offset; src->cs = cs; src->val = src_val; src->index = src_idx; src->next = sources; sources = src; } /* Allocate a new ipcp_value holding a tree constant, initialize its value to SOURCE and clear all other fields. */ static ipcp_value * allocate_and_init_ipcp_value (tree source) { ipcp_value *val; val = new (pool_alloc (ipcp_cst_values_pool)) ipcp_value; memset (val, 0, sizeof (*val)); val->value = source; return val; } /* Allocate a new ipcp_value holding a polymorphic context, initialize its value to SOURCE and clear all other fields. */ static ipcp_value * allocate_and_init_ipcp_value (ipa_polymorphic_call_context source) { ipcp_value *val; val = new (pool_alloc (ipcp_poly_ctx_values_pool)) ipcp_value; memset (val, 0, sizeof (*val)); val->value = source; return val; } /* Try to add NEWVAL to LAT, potentially creating a new ipcp_value for it. CS, SRC_VAL SRC_INDEX and OFFSET are meant for add_source and have the same meaning. OFFSET -1 means the source is scalar and not a part of an aggregate. */ template bool ipcp_lattice::add_value (valtype newval, cgraph_edge *cs, ipcp_value *src_val, int src_idx, HOST_WIDE_INT offset) { ipcp_value *val; if (bottom) return false; for (val = values; val; val = val->next) if (values_equal_for_ipcp_p (val->value, newval)) { if (ipa_edge_within_scc (cs)) { ipcp_value_source *s; for (s = val->sources; s ; s = s->next) if (s->cs == cs) break; if (s) return false; } val->add_source (cs, src_val, src_idx, offset); return false; } if (values_count == PARAM_VALUE (PARAM_IPA_CP_VALUE_LIST_SIZE)) { /* We can only free sources, not the values themselves, because sources of other values in this this SCC might point to them. */ for (val = values; val; val = val->next) { while (val->sources) { ipcp_value_source *src = val->sources; val->sources = src->next; pool_free (ipcp_sources_pool, src); } } values = NULL; return set_to_bottom (); } values_count++; val = allocate_and_init_ipcp_value (newval); val->add_source (cs, src_val, src_idx, offset); val->next = values; values = val; return true; } /* Propagate values through a pass-through jump function JFUNC associated with edge CS, taking values from SRC_LAT and putting them into DEST_LAT. SRC_IDX is the index of the source parameter. */ static bool propagate_vals_accross_pass_through (cgraph_edge *cs, ipa_jump_func *jfunc, ipcp_lattice *src_lat, ipcp_lattice *dest_lat, int src_idx) { ipcp_value *src_val; bool ret = false; /* Do not create new values when propagating within an SCC because if there are arithmetic functions with circular dependencies, there is infinite number of them and we would just make lattices bottom. */ if ((ipa_get_jf_pass_through_operation (jfunc) != NOP_EXPR) && ipa_edge_within_scc (cs)) ret = dest_lat->set_contains_variable (); else for (src_val = src_lat->values; src_val; src_val = src_val->next) { tree cstval = ipa_get_jf_pass_through_result (jfunc, src_val->value); if (cstval) ret |= dest_lat->add_value (cstval, cs, src_val, src_idx); else ret |= dest_lat->set_contains_variable (); } return ret; } /* Propagate values through an ancestor jump function JFUNC associated with edge CS, taking values from SRC_LAT and putting them into DEST_LAT. SRC_IDX is the index of the source parameter. */ static bool propagate_vals_accross_ancestor (struct cgraph_edge *cs, struct ipa_jump_func *jfunc, ipcp_lattice *src_lat, ipcp_lattice *dest_lat, int src_idx) { ipcp_value *src_val; bool ret = false; if (ipa_edge_within_scc (cs)) return dest_lat->set_contains_variable (); for (src_val = src_lat->values; src_val; src_val = src_val->next) { tree t = ipa_get_jf_ancestor_result (jfunc, src_val->value); if (t) ret |= dest_lat->add_value (t, cs, src_val, src_idx); else ret |= dest_lat->set_contains_variable (); } return ret; } /* Propagate scalar values across jump function JFUNC that is associated with edge CS and put the values into DEST_LAT. */ static bool propagate_scalar_accross_jump_function (struct cgraph_edge *cs, struct ipa_jump_func *jfunc, ipcp_lattice *dest_lat) { if (dest_lat->bottom) return false; if (jfunc->type == IPA_JF_CONST) { tree val = ipa_get_jf_constant (jfunc); return dest_lat->add_value (val, cs, NULL, 0); } else if (jfunc->type == IPA_JF_PASS_THROUGH || jfunc->type == IPA_JF_ANCESTOR) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); ipcp_lattice *src_lat; int src_idx; bool ret; if (jfunc->type == IPA_JF_PASS_THROUGH) src_idx = ipa_get_jf_pass_through_formal_id (jfunc); else src_idx = ipa_get_jf_ancestor_formal_id (jfunc); src_lat = ipa_get_scalar_lat (caller_info, src_idx); if (src_lat->bottom) return dest_lat->set_contains_variable (); /* If we would need to clone the caller and cannot, do not propagate. */ if (!ipcp_versionable_function_p (cs->caller) && (src_lat->contains_variable || (src_lat->values_count > 1))) return dest_lat->set_contains_variable (); if (jfunc->type == IPA_JF_PASS_THROUGH) ret = propagate_vals_accross_pass_through (cs, jfunc, src_lat, dest_lat, src_idx); else ret = propagate_vals_accross_ancestor (cs, jfunc, src_lat, dest_lat, src_idx); if (src_lat->contains_variable) ret |= dest_lat->set_contains_variable (); return ret; } /* TODO: We currently do not handle member method pointers in IPA-CP (we only use it for indirect inlining), we should propagate them too. */ return dest_lat->set_contains_variable (); } /* Propagate scalar values across jump function JFUNC that is associated with edge CS and describes argument IDX and put the values into DEST_LAT. */ static bool propagate_context_accross_jump_function (cgraph_edge *cs, ipa_jump_func *jfunc, int idx, ipcp_lattice *dest_lat) { ipa_edge_args *args = IPA_EDGE_REF (cs); if (dest_lat->bottom) return false; bool ret = false; bool added_sth = false; bool type_preserved = true; ipa_polymorphic_call_context edge_ctx, *edge_ctx_ptr = ipa_get_ith_polymorhic_call_context (args, idx); if (edge_ctx_ptr) edge_ctx = *edge_ctx_ptr; if (jfunc->type == IPA_JF_PASS_THROUGH || jfunc->type == IPA_JF_ANCESTOR) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); int src_idx; ipcp_lattice *src_lat; /* TODO: Once we figure out how to propagate speculations, it will probably be a good idea to switch to speculation if type_preserved is not set instead of punting. */ if (jfunc->type == IPA_JF_PASS_THROUGH) { if (ipa_get_jf_pass_through_operation (jfunc) != NOP_EXPR) goto prop_fail; type_preserved = ipa_get_jf_pass_through_type_preserved (jfunc); src_idx = ipa_get_jf_pass_through_formal_id (jfunc); } else { type_preserved = ipa_get_jf_ancestor_type_preserved (jfunc); src_idx = ipa_get_jf_ancestor_formal_id (jfunc); } src_lat = ipa_get_poly_ctx_lat (caller_info, src_idx); /* If we would need to clone the caller and cannot, do not propagate. */ if (!ipcp_versionable_function_p (cs->caller) && (src_lat->contains_variable || (src_lat->values_count > 1))) goto prop_fail; ipcp_value *src_val; for (src_val = src_lat->values; src_val; src_val = src_val->next) { ipa_polymorphic_call_context cur = src_val->value; if (!type_preserved) cur.possible_dynamic_type_change (cs->in_polymorphic_cdtor); if (jfunc->type == IPA_JF_ANCESTOR) cur.offset_by (ipa_get_jf_ancestor_offset (jfunc)); /* TODO: In cases we know how the context is going to be used, we can improve the result by passing proper OTR_TYPE. */ cur.combine_with (edge_ctx); if (!cur.useless_p ()) { if (src_lat->contains_variable && !edge_ctx.equal_to (cur)) ret |= dest_lat->set_contains_variable (); ret |= dest_lat->add_value (cur, cs, src_val, src_idx); added_sth = true; } } } prop_fail: if (!added_sth) { if (!edge_ctx.useless_p ()) ret |= dest_lat->add_value (edge_ctx, cs); else ret |= dest_lat->set_contains_variable (); } return ret; } /* Propagate alignments across jump function JFUNC that is associated with edge CS and update DEST_LAT accordingly. */ static bool propagate_alignment_accross_jump_function (struct cgraph_edge *cs, struct ipa_jump_func *jfunc, struct ipcp_param_lattices *dest_lat) { if (alignment_bottom_p (dest_lat)) return false; ipa_alignment cur; cur.known = false; if (jfunc->alignment.known) cur = jfunc->alignment; else if (jfunc->type == IPA_JF_PASS_THROUGH || jfunc->type == IPA_JF_ANCESTOR) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); struct ipcp_param_lattices *src_lats; HOST_WIDE_INT offset = 0; int src_idx; if (jfunc->type == IPA_JF_PASS_THROUGH) { enum tree_code op = ipa_get_jf_pass_through_operation (jfunc); if (op != NOP_EXPR) { if (op != POINTER_PLUS_EXPR && op != PLUS_EXPR && op != MINUS_EXPR) goto prop_fail; tree operand = ipa_get_jf_pass_through_operand (jfunc); if (!tree_fits_shwi_p (operand)) goto prop_fail; offset = tree_to_shwi (operand); } src_idx = ipa_get_jf_pass_through_formal_id (jfunc); } else { src_idx = ipa_get_jf_ancestor_formal_id (jfunc); offset = ipa_get_jf_ancestor_offset (jfunc); } src_lats = ipa_get_parm_lattices (caller_info, src_idx); if (!src_lats->alignment.known || alignment_bottom_p (src_lats)) goto prop_fail; cur = src_lats->alignment; cur.misalign = (cur.misalign + offset) % cur.align; } if (cur.known) { if (!dest_lat->alignment.known) { dest_lat->alignment = cur; return true; } else if (dest_lat->alignment.align == cur.align && dest_lat->alignment.misalign == cur.misalign) return false; } prop_fail: set_alignment_to_bottom (dest_lat); return true; } /* If DEST_PLATS already has aggregate items, check that aggs_by_ref matches NEW_AGGS_BY_REF and if not, mark all aggs as bottoms and return true (in all other cases, return false). If there are no aggregate items, set aggs_by_ref to NEW_AGGS_BY_REF. */ static bool set_check_aggs_by_ref (struct ipcp_param_lattices *dest_plats, bool new_aggs_by_ref) { if (dest_plats->aggs) { if (dest_plats->aggs_by_ref != new_aggs_by_ref) { set_agg_lats_to_bottom (dest_plats); return true; } } else dest_plats->aggs_by_ref = new_aggs_by_ref; return false; } /* Walk aggregate lattices in DEST_PLATS from ***AGLAT on, until ***aglat is an already existing lattice for the given OFFSET and SIZE, marking all skipped lattices as containing variable and checking for overlaps. If there is no already existing lattice for the OFFSET and VAL_SIZE, create one, initialize it with offset, size and contains_variable to PRE_EXISTING, and return true, unless there are too many already. If there are two many, return false. If there are overlaps turn whole DEST_PLATS to bottom and return false. If any skipped lattices were newly marked as containing variable, set *CHANGE to true. */ static bool merge_agg_lats_step (struct ipcp_param_lattices *dest_plats, HOST_WIDE_INT offset, HOST_WIDE_INT val_size, struct ipcp_agg_lattice ***aglat, bool pre_existing, bool *change) { gcc_checking_assert (offset >= 0); while (**aglat && (**aglat)->offset < offset) { if ((**aglat)->offset + (**aglat)->size > offset) { set_agg_lats_to_bottom (dest_plats); return false; } *change |= (**aglat)->set_contains_variable (); *aglat = &(**aglat)->next; } if (**aglat && (**aglat)->offset == offset) { if ((**aglat)->size != val_size || ((**aglat)->next && (**aglat)->next->offset < offset + val_size)) { set_agg_lats_to_bottom (dest_plats); return false; } gcc_checking_assert (!(**aglat)->next || (**aglat)->next->offset >= offset + val_size); return true; } else { struct ipcp_agg_lattice *new_al; if (**aglat && (**aglat)->offset < offset + val_size) { set_agg_lats_to_bottom (dest_plats); return false; } if (dest_plats->aggs_count == PARAM_VALUE (PARAM_IPA_MAX_AGG_ITEMS)) return false; dest_plats->aggs_count++; new_al = (struct ipcp_agg_lattice *) pool_alloc (ipcp_agg_lattice_pool); memset (new_al, 0, sizeof (*new_al)); new_al->offset = offset; new_al->size = val_size; new_al->contains_variable = pre_existing; new_al->next = **aglat; **aglat = new_al; return true; } } /* Set all AGLAT and all other aggregate lattices reachable by next pointers as containing an unknown value. */ static bool set_chain_of_aglats_contains_variable (struct ipcp_agg_lattice *aglat) { bool ret = false; while (aglat) { ret |= aglat->set_contains_variable (); aglat = aglat->next; } return ret; } /* Merge existing aggregate lattices in SRC_PLATS to DEST_PLATS, subtracting DELTA_OFFSET. CS is the call graph edge and SRC_IDX the index of the source parameter used for lattice value sources. Return true if DEST_PLATS changed in any way. */ static bool merge_aggregate_lattices (struct cgraph_edge *cs, struct ipcp_param_lattices *dest_plats, struct ipcp_param_lattices *src_plats, int src_idx, HOST_WIDE_INT offset_delta) { bool pre_existing = dest_plats->aggs != NULL; struct ipcp_agg_lattice **dst_aglat; bool ret = false; if (set_check_aggs_by_ref (dest_plats, src_plats->aggs_by_ref)) return true; if (src_plats->aggs_bottom) return set_agg_lats_contain_variable (dest_plats); if (src_plats->aggs_contain_variable) ret |= set_agg_lats_contain_variable (dest_plats); dst_aglat = &dest_plats->aggs; for (struct ipcp_agg_lattice *src_aglat = src_plats->aggs; src_aglat; src_aglat = src_aglat->next) { HOST_WIDE_INT new_offset = src_aglat->offset - offset_delta; if (new_offset < 0) continue; if (merge_agg_lats_step (dest_plats, new_offset, src_aglat->size, &dst_aglat, pre_existing, &ret)) { struct ipcp_agg_lattice *new_al = *dst_aglat; dst_aglat = &(*dst_aglat)->next; if (src_aglat->bottom) { ret |= new_al->set_contains_variable (); continue; } if (src_aglat->contains_variable) ret |= new_al->set_contains_variable (); for (ipcp_value *val = src_aglat->values; val; val = val->next) ret |= new_al->add_value (val->value, cs, val, src_idx, src_aglat->offset); } else if (dest_plats->aggs_bottom) return true; } ret |= set_chain_of_aglats_contains_variable (*dst_aglat); return ret; } /* Determine whether there is anything to propagate FROM SRC_PLATS through a pass-through JFUNC and if so, whether it has conform and conforms to the rules about propagating values passed by reference. */ static bool agg_pass_through_permissible_p (struct ipcp_param_lattices *src_plats, struct ipa_jump_func *jfunc) { return src_plats->aggs && (!src_plats->aggs_by_ref || ipa_get_jf_pass_through_agg_preserved (jfunc)); } /* Propagate scalar values across jump function JFUNC that is associated with edge CS and put the values into DEST_LAT. */ static bool propagate_aggs_accross_jump_function (struct cgraph_edge *cs, struct ipa_jump_func *jfunc, struct ipcp_param_lattices *dest_plats) { bool ret = false; if (dest_plats->aggs_bottom) return false; if (jfunc->type == IPA_JF_PASS_THROUGH && ipa_get_jf_pass_through_operation (jfunc) == NOP_EXPR) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); int src_idx = ipa_get_jf_pass_through_formal_id (jfunc); struct ipcp_param_lattices *src_plats; src_plats = ipa_get_parm_lattices (caller_info, src_idx); if (agg_pass_through_permissible_p (src_plats, jfunc)) { /* Currently we do not produce clobber aggregate jump functions, replace with merging when we do. */ gcc_assert (!jfunc->agg.items); ret |= merge_aggregate_lattices (cs, dest_plats, src_plats, src_idx, 0); } else ret |= set_agg_lats_contain_variable (dest_plats); } else if (jfunc->type == IPA_JF_ANCESTOR && ipa_get_jf_ancestor_agg_preserved (jfunc)) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); int src_idx = ipa_get_jf_ancestor_formal_id (jfunc); struct ipcp_param_lattices *src_plats; src_plats = ipa_get_parm_lattices (caller_info, src_idx); if (src_plats->aggs && src_plats->aggs_by_ref) { /* Currently we do not produce clobber aggregate jump functions, replace with merging when we do. */ gcc_assert (!jfunc->agg.items); ret |= merge_aggregate_lattices (cs, dest_plats, src_plats, src_idx, ipa_get_jf_ancestor_offset (jfunc)); } else if (!src_plats->aggs_by_ref) ret |= set_agg_lats_to_bottom (dest_plats); else ret |= set_agg_lats_contain_variable (dest_plats); } else if (jfunc->agg.items) { bool pre_existing = dest_plats->aggs != NULL; struct ipcp_agg_lattice **aglat = &dest_plats->aggs; struct ipa_agg_jf_item *item; int i; if (set_check_aggs_by_ref (dest_plats, jfunc->agg.by_ref)) return true; FOR_EACH_VEC_ELT (*jfunc->agg.items, i, item) { HOST_WIDE_INT val_size; if (item->offset < 0) continue; gcc_checking_assert (is_gimple_ip_invariant (item->value)); val_size = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (item->value))); if (merge_agg_lats_step (dest_plats, item->offset, val_size, &aglat, pre_existing, &ret)) { ret |= (*aglat)->add_value (item->value, cs, NULL, 0, 0); aglat = &(*aglat)->next; } else if (dest_plats->aggs_bottom) return true; } ret |= set_chain_of_aglats_contains_variable (*aglat); } else ret |= set_agg_lats_contain_variable (dest_plats); return ret; } /* Propagate constants from the caller to the callee of CS. INFO describes the caller. */ static bool propagate_constants_accross_call (struct cgraph_edge *cs) { struct ipa_node_params *callee_info; enum availability availability; struct cgraph_node *callee, *alias_or_thunk; struct ipa_edge_args *args; bool ret = false; int i, args_count, parms_count; callee = cs->callee->function_symbol (&availability); if (!callee->definition) return false; gcc_checking_assert (callee->has_gimple_body_p ()); callee_info = IPA_NODE_REF (callee); args = IPA_EDGE_REF (cs); args_count = ipa_get_cs_argument_count (args); parms_count = ipa_get_param_count (callee_info); if (parms_count == 0) return false; /* No propagation through instrumentation thunks is available yet. It should be possible with proper mapping of call args and instrumented callee params in the propagation loop below. But this case mostly occurs when legacy code calls instrumented code and it is not a primary target for optimizations. We detect instrumentation thunks in aliases and thunks chain by checking instrumentation_clone flag for chain source and target. Going through instrumentation thunks we always have it changed from 0 to 1 and all other nodes do not change it. */ if (!cs->callee->instrumentation_clone && callee->instrumentation_clone) { for (i = 0; i < parms_count; i++) ret |= set_all_contains_variable (ipa_get_parm_lattices (callee_info, i)); return ret; } /* If this call goes through a thunk we must not propagate to the first (0th) parameter. However, we might need to uncover a thunk from below a series of aliases first. */ alias_or_thunk = cs->callee; while (alias_or_thunk->alias) alias_or_thunk = alias_or_thunk->get_alias_target (); if (alias_or_thunk->thunk.thunk_p) { ret |= set_all_contains_variable (ipa_get_parm_lattices (callee_info, 0)); i = 1; } else i = 0; for (; (i < args_count) && (i < parms_count); i++) { struct ipa_jump_func *jump_func = ipa_get_ith_jump_func (args, i); struct ipcp_param_lattices *dest_plats; dest_plats = ipa_get_parm_lattices (callee_info, i); if (availability == AVAIL_INTERPOSABLE) ret |= set_all_contains_variable (dest_plats); else { ret |= propagate_scalar_accross_jump_function (cs, jump_func, &dest_plats->itself); ret |= propagate_context_accross_jump_function (cs, jump_func, i, &dest_plats->ctxlat); ret |= propagate_alignment_accross_jump_function (cs, jump_func, dest_plats); ret |= propagate_aggs_accross_jump_function (cs, jump_func, dest_plats); } } for (; i < parms_count; i++) ret |= set_all_contains_variable (ipa_get_parm_lattices (callee_info, i)); return ret; } /* If an indirect edge IE can be turned into a direct one based on KNOWN_VALS KNOWN_CONTEXTS, KNOWN_AGGS or AGG_REPS return the destination. The latter three can be NULL. If AGG_REPS is not NULL, KNOWN_AGGS is ignored. */ static tree ipa_get_indirect_edge_target_1 (struct cgraph_edge *ie, vec known_csts, vec known_contexts, vec known_aggs, struct ipa_agg_replacement_value *agg_reps, bool *speculative) { int param_index = ie->indirect_info->param_index; HOST_WIDE_INT anc_offset; tree t; tree target = NULL; *speculative = false; if (param_index == -1 || known_csts.length () <= (unsigned int) param_index) return NULL_TREE; if (!ie->indirect_info->polymorphic) { tree t; if (ie->indirect_info->agg_contents) { if (agg_reps) { t = NULL; while (agg_reps) { if (agg_reps->index == param_index && agg_reps->offset == ie->indirect_info->offset && agg_reps->by_ref == ie->indirect_info->by_ref) { t = agg_reps->value; break; } agg_reps = agg_reps->next; } } else if (known_aggs.length () > (unsigned int) param_index) { struct ipa_agg_jump_function *agg; agg = known_aggs[param_index]; t = ipa_find_agg_cst_for_param (agg, ie->indirect_info->offset, ie->indirect_info->by_ref); } else t = NULL; } else t = known_csts[param_index]; if (t && TREE_CODE (t) == ADDR_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == FUNCTION_DECL) return TREE_OPERAND (t, 0); else return NULL_TREE; } if (!opt_for_fn (ie->caller->decl, flag_devirtualize)) return NULL_TREE; gcc_assert (!ie->indirect_info->agg_contents); anc_offset = ie->indirect_info->offset; t = NULL; /* Try to work out value of virtual table pointer value in replacemnets. */ if (!t && agg_reps && !ie->indirect_info->by_ref) { while (agg_reps) { if (agg_reps->index == param_index && agg_reps->offset == ie->indirect_info->offset && agg_reps->by_ref) { t = agg_reps->value; break; } agg_reps = agg_reps->next; } } /* Try to work out value of virtual table pointer value in known aggregate values. */ if (!t && known_aggs.length () > (unsigned int) param_index && !ie->indirect_info->by_ref) { struct ipa_agg_jump_function *agg; agg = known_aggs[param_index]; t = ipa_find_agg_cst_for_param (agg, ie->indirect_info->offset, true); } /* If we found the virtual table pointer, lookup the target. */ if (t) { tree vtable; unsigned HOST_WIDE_INT offset; if (vtable_pointer_value_to_vtable (t, &vtable, &offset)) { target = gimple_get_virt_method_for_vtable (ie->indirect_info->otr_token, vtable, offset); if (target) { if ((TREE_CODE (TREE_TYPE (target)) == FUNCTION_TYPE && DECL_FUNCTION_CODE (target) == BUILT_IN_UNREACHABLE) || !possible_polymorphic_call_target_p (ie, cgraph_node::get (target))) target = ipa_impossible_devirt_target (ie, target); *speculative = ie->indirect_info->vptr_changed; if (!*speculative) return target; } } } /* Do we know the constant value of pointer? */ if (!t) t = known_csts[param_index]; gcc_checking_assert (!t || TREE_CODE (t) != TREE_BINFO); ipa_polymorphic_call_context context; if (known_contexts.length () > (unsigned int) param_index) { context = known_contexts[param_index]; context.offset_by (anc_offset); if (ie->indirect_info->vptr_changed) context.possible_dynamic_type_change (ie->in_polymorphic_cdtor, ie->indirect_info->otr_type); if (t) { ipa_polymorphic_call_context ctx2 = ipa_polymorphic_call_context (t, ie->indirect_info->otr_type, anc_offset); if (!ctx2.useless_p ()) context.combine_with (ctx2, ie->indirect_info->otr_type); } } else if (t) { context = ipa_polymorphic_call_context (t, ie->indirect_info->otr_type, anc_offset); if (ie->indirect_info->vptr_changed) context.possible_dynamic_type_change (ie->in_polymorphic_cdtor, ie->indirect_info->otr_type); } else return NULL_TREE; vec targets; bool final; targets = possible_polymorphic_call_targets (ie->indirect_info->otr_type, ie->indirect_info->otr_token, context, &final); if (!final || targets.length () > 1) { struct cgraph_node *node; if (*speculative) return target; if (!opt_for_fn (ie->caller->decl, flag_devirtualize_speculatively) || ie->speculative || !ie->maybe_hot_p ()) return NULL; node = try_speculative_devirtualization (ie->indirect_info->otr_type, ie->indirect_info->otr_token, context); if (node) { *speculative = true; target = node->decl; } else return NULL; } else { *speculative = false; if (targets.length () == 1) target = targets[0]->decl; else target = ipa_impossible_devirt_target (ie, NULL_TREE); } if (target && !possible_polymorphic_call_target_p (ie, cgraph_node::get (target))) target = ipa_impossible_devirt_target (ie, target); return target; } /* If an indirect edge IE can be turned into a direct one based on KNOWN_CSTS, KNOWN_CONTEXTS (which can be vNULL) or KNOWN_AGGS (which also can be vNULL) return the destination. */ tree ipa_get_indirect_edge_target (struct cgraph_edge *ie, vec known_csts, vec known_contexts, vec known_aggs, bool *speculative) { return ipa_get_indirect_edge_target_1 (ie, known_csts, known_contexts, known_aggs, NULL, speculative); } /* Calculate devirtualization time bonus for NODE, assuming we know KNOWN_CSTS and KNOWN_CONTEXTS. */ static int devirtualization_time_bonus (struct cgraph_node *node, vec known_csts, vec known_contexts, vec known_aggs) { struct cgraph_edge *ie; int res = 0; for (ie = node->indirect_calls; ie; ie = ie->next_callee) { struct cgraph_node *callee; struct inline_summary *isummary; enum availability avail; tree target; bool speculative; target = ipa_get_indirect_edge_target (ie, known_csts, known_contexts, known_aggs, &speculative); if (!target) continue; /* Only bare minimum benefit for clearly un-inlineable targets. */ res += 1; callee = cgraph_node::get (target); if (!callee || !callee->definition) continue; callee = callee->function_symbol (&avail); if (avail < AVAIL_AVAILABLE) continue; isummary = inline_summaries->get (callee); if (!isummary->inlinable) continue; /* FIXME: The values below need re-considering and perhaps also integrating into the cost metrics, at lest in some very basic way. */ if (isummary->size <= MAX_INLINE_INSNS_AUTO / 4) res += 31 / ((int)speculative + 1); else if (isummary->size <= MAX_INLINE_INSNS_AUTO / 2) res += 15 / ((int)speculative + 1); else if (isummary->size <= MAX_INLINE_INSNS_AUTO || DECL_DECLARED_INLINE_P (callee->decl)) res += 7 / ((int)speculative + 1); } return res; } /* Return time bonus incurred because of HINTS. */ static int hint_time_bonus (inline_hints hints) { int result = 0; if (hints & (INLINE_HINT_loop_iterations | INLINE_HINT_loop_stride)) result += PARAM_VALUE (PARAM_IPA_CP_LOOP_HINT_BONUS); if (hints & INLINE_HINT_array_index) result += PARAM_VALUE (PARAM_IPA_CP_ARRAY_INDEX_HINT_BONUS); return result; } /* Return true if cloning NODE is a good idea, given the estimated TIME_BENEFIT and SIZE_COST and with the sum of frequencies of incoming edges to the potential new clone in FREQUENCIES. */ static bool good_cloning_opportunity_p (struct cgraph_node *node, int time_benefit, int freq_sum, gcov_type count_sum, int size_cost) { if (time_benefit == 0 || !opt_for_fn (node->decl, flag_ipa_cp_clone) || !optimize_function_for_speed_p (DECL_STRUCT_FUNCTION (node->decl))) return false; gcc_assert (size_cost > 0); if (max_count) { int factor = (count_sum * 1000) / max_count; int64_t evaluation = (((int64_t) time_benefit * factor) / size_cost); if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " good_cloning_opportunity_p (time: %i, " "size: %i, count_sum: " HOST_WIDE_INT_PRINT_DEC ") -> evaluation: " "%"PRId64 ", threshold: %i\n", time_benefit, size_cost, (HOST_WIDE_INT) count_sum, evaluation, PARAM_VALUE (PARAM_IPA_CP_EVAL_THRESHOLD)); return evaluation >= PARAM_VALUE (PARAM_IPA_CP_EVAL_THRESHOLD); } else { int64_t evaluation = (((int64_t) time_benefit * freq_sum) / size_cost); if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " good_cloning_opportunity_p (time: %i, " "size: %i, freq_sum: %i) -> evaluation: " "%"PRId64 ", threshold: %i\n", time_benefit, size_cost, freq_sum, evaluation, PARAM_VALUE (PARAM_IPA_CP_EVAL_THRESHOLD)); return evaluation >= PARAM_VALUE (PARAM_IPA_CP_EVAL_THRESHOLD); } } /* Return all context independent values from aggregate lattices in PLATS in a vector. Return NULL if there are none. */ static vec * context_independent_aggregate_values (struct ipcp_param_lattices *plats) { vec *res = NULL; if (plats->aggs_bottom || plats->aggs_contain_variable || plats->aggs_count == 0) return NULL; for (struct ipcp_agg_lattice *aglat = plats->aggs; aglat; aglat = aglat->next) if (aglat->is_single_const ()) { struct ipa_agg_jf_item item; item.offset = aglat->offset; item.value = aglat->values->value; vec_safe_push (res, item); } return res; } /* Allocate KNOWN_CSTS, KNOWN_CONTEXTS and, if non-NULL, KNOWN_AGGS and populate them with values of parameters that are known independent of the context. INFO describes the function. If REMOVABLE_PARAMS_COST is non-NULL, the movement cost of all removable parameters will be stored in it. */ static bool gather_context_independent_values (struct ipa_node_params *info, vec *known_csts, vec *known_contexts, vec *known_aggs, int *removable_params_cost) { int i, count = ipa_get_param_count (info); bool ret = false; known_csts->create (0); known_contexts->create (0); known_csts->safe_grow_cleared (count); known_contexts->safe_grow_cleared (count); if (known_aggs) { known_aggs->create (0); known_aggs->safe_grow_cleared (count); } if (removable_params_cost) *removable_params_cost = 0; for (i = 0; i < count ; i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); ipcp_lattice *lat = &plats->itself; if (lat->is_single_const ()) { ipcp_value *val = lat->values; gcc_checking_assert (TREE_CODE (val->value) != TREE_BINFO); (*known_csts)[i] = val->value; if (removable_params_cost) *removable_params_cost += estimate_move_cost (TREE_TYPE (val->value), false); ret = true; } else if (removable_params_cost && !ipa_is_param_used (info, i)) *removable_params_cost += ipa_get_param_move_cost (info, i); ipcp_lattice *ctxlat = &plats->ctxlat; if (ctxlat->is_single_const ()) { (*known_contexts)[i] = ctxlat->values->value; ret = true; } if (known_aggs) { vec *agg_items; struct ipa_agg_jump_function *ajf; agg_items = context_independent_aggregate_values (plats); ajf = &(*known_aggs)[i]; ajf->items = agg_items; ajf->by_ref = plats->aggs_by_ref; ret |= agg_items != NULL; } } return ret; } /* The current interface in ipa-inline-analysis requires a pointer vector. Create it. FIXME: That interface should be re-worked, this is slightly silly. Still, I'd like to discuss how to change it first and this demonstrates the issue. */ static vec agg_jmp_p_vec_for_t_vec (vec known_aggs) { vec ret; struct ipa_agg_jump_function *ajf; int i; ret.create (known_aggs.length ()); FOR_EACH_VEC_ELT (known_aggs, i, ajf) ret.quick_push (ajf); return ret; } /* Perform time and size measurement of NODE with the context given in KNOWN_CSTS, KNOWN_CONTEXTS and KNOWN_AGGS, calculate the benefit and cost given BASE_TIME of the node without specialization, REMOVABLE_PARAMS_COST of all context-independent removable parameters and EST_MOVE_COST of estimated movement of the considered parameter and store it into VAL. */ static void perform_estimation_of_a_value (cgraph_node *node, vec known_csts, vec known_contexts, vec known_aggs_ptrs, int base_time, int removable_params_cost, int est_move_cost, ipcp_value_base *val) { int time, size, time_benefit; inline_hints hints; estimate_ipcp_clone_size_and_time (node, known_csts, known_contexts, known_aggs_ptrs, &size, &time, &hints); time_benefit = base_time - time + devirtualization_time_bonus (node, known_csts, known_contexts, known_aggs_ptrs) + hint_time_bonus (hints) + removable_params_cost + est_move_cost; gcc_checking_assert (size >=0); /* The inliner-heuristics based estimates may think that in certain contexts some functions do not have any size at all but we want all specializations to have at least a tiny cost, not least not to divide by zero. */ if (size == 0) size = 1; val->local_time_benefit = time_benefit; val->local_size_cost = size; } /* Iterate over known values of parameters of NODE and estimate the local effects in terms of time and size they have. */ static void estimate_local_effects (struct cgraph_node *node) { struct ipa_node_params *info = IPA_NODE_REF (node); int i, count = ipa_get_param_count (info); vec known_csts; vec known_contexts; vec known_aggs; vec known_aggs_ptrs; bool always_const; int base_time = inline_summaries->get (node)->time; int removable_params_cost; if (!count || !ipcp_versionable_function_p (node)) return; if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "\nEstimating effects for %s/%i, base_time: %i.\n", node->name (), node->order, base_time); always_const = gather_context_independent_values (info, &known_csts, &known_contexts, &known_aggs, &removable_params_cost); known_aggs_ptrs = agg_jmp_p_vec_for_t_vec (known_aggs); if (always_const) { struct caller_statistics stats; inline_hints hints; int time, size; init_caller_stats (&stats); node->call_for_symbol_thunks_and_aliases (gather_caller_stats, &stats, false); estimate_ipcp_clone_size_and_time (node, known_csts, known_contexts, known_aggs_ptrs, &size, &time, &hints); time -= devirtualization_time_bonus (node, known_csts, known_contexts, known_aggs_ptrs); time -= hint_time_bonus (hints); time -= removable_params_cost; size -= stats.n_calls * removable_params_cost; if (dump_file) fprintf (dump_file, " - context independent values, size: %i, " "time_benefit: %i\n", size, base_time - time); if (size <= 0 || node->will_be_removed_from_program_if_no_direct_calls_p ()) { info->do_clone_for_all_contexts = true; base_time = time; if (dump_file) fprintf (dump_file, " Decided to specialize for all " "known contexts, code not going to grow.\n"); } else if (good_cloning_opportunity_p (node, base_time - time, stats.freq_sum, stats.count_sum, size)) { if (size + overall_size <= max_new_size) { info->do_clone_for_all_contexts = true; base_time = time; overall_size += size; if (dump_file) fprintf (dump_file, " Decided to specialize for all " "known contexts, growth deemed beneficial.\n"); } else if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " Not cloning for all contexts because " "max_new_size would be reached with %li.\n", size + overall_size); } } for (i = 0; i < count ; i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); ipcp_lattice *lat = &plats->itself; ipcp_value *val; if (lat->bottom || !lat->values || known_csts[i]) continue; for (val = lat->values; val; val = val->next) { gcc_checking_assert (TREE_CODE (val->value) != TREE_BINFO); known_csts[i] = val->value; int emc = estimate_move_cost (TREE_TYPE (val->value), true); perform_estimation_of_a_value (node, known_csts, known_contexts, known_aggs_ptrs, base_time, removable_params_cost, emc, val); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " - estimates for value "); print_ipcp_constant_value (dump_file, val->value); fprintf (dump_file, " for "); ipa_dump_param (dump_file, info, i); fprintf (dump_file, ": time_benefit: %i, size: %i\n", val->local_time_benefit, val->local_size_cost); } } known_csts[i] = NULL_TREE; } for (i = 0; i < count; i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); if (!plats->virt_call) continue; ipcp_lattice *ctxlat = &plats->ctxlat; ipcp_value *val; if (ctxlat->bottom || !ctxlat->values || !known_contexts[i].useless_p ()) continue; for (val = ctxlat->values; val; val = val->next) { known_contexts[i] = val->value; perform_estimation_of_a_value (node, known_csts, known_contexts, known_aggs_ptrs, base_time, removable_params_cost, 0, val); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " - estimates for polymorphic context "); print_ipcp_constant_value (dump_file, val->value); fprintf (dump_file, " for "); ipa_dump_param (dump_file, info, i); fprintf (dump_file, ": time_benefit: %i, size: %i\n", val->local_time_benefit, val->local_size_cost); } } known_contexts[i] = ipa_polymorphic_call_context (); } for (i = 0; i < count ; i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); struct ipa_agg_jump_function *ajf; struct ipcp_agg_lattice *aglat; if (plats->aggs_bottom || !plats->aggs) continue; ajf = &known_aggs[i]; for (aglat = plats->aggs; aglat; aglat = aglat->next) { ipcp_value *val; if (aglat->bottom || !aglat->values /* If the following is true, the one value is in known_aggs. */ || (!plats->aggs_contain_variable && aglat->is_single_const ())) continue; for (val = aglat->values; val; val = val->next) { struct ipa_agg_jf_item item; item.offset = aglat->offset; item.value = val->value; vec_safe_push (ajf->items, item); perform_estimation_of_a_value (node, known_csts, known_contexts, known_aggs_ptrs, base_time, removable_params_cost, 0, val); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " - estimates for value "); print_ipcp_constant_value (dump_file, val->value); fprintf (dump_file, " for "); ipa_dump_param (dump_file, info, i); fprintf (dump_file, "[%soffset: " HOST_WIDE_INT_PRINT_DEC "]: time_benefit: %i, size: %i\n", plats->aggs_by_ref ? "ref " : "", aglat->offset, val->local_time_benefit, val->local_size_cost); } ajf->items->pop (); } } } for (i = 0; i < count ; i++) vec_free (known_aggs[i].items); known_csts.release (); known_contexts.release (); known_aggs.release (); known_aggs_ptrs.release (); } /* Add value CUR_VAL and all yet-unsorted values it is dependent on to the topological sort of values. */ template void value_topo_info::add_val (ipcp_value *cur_val) { ipcp_value_source *src; if (cur_val->dfs) return; dfs_counter++; cur_val->dfs = dfs_counter; cur_val->low_link = dfs_counter; cur_val->topo_next = stack; stack = cur_val; cur_val->on_stack = true; for (src = cur_val->sources; src; src = src->next) if (src->val) { if (src->val->dfs == 0) { add_val (src->val); if (src->val->low_link < cur_val->low_link) cur_val->low_link = src->val->low_link; } else if (src->val->on_stack && src->val->dfs < cur_val->low_link) cur_val->low_link = src->val->dfs; } if (cur_val->dfs == cur_val->low_link) { ipcp_value *v, *scc_list = NULL; do { v = stack; stack = v->topo_next; v->on_stack = false; v->scc_next = scc_list; scc_list = v; } while (v != cur_val); cur_val->topo_next = values_topo; values_topo = cur_val; } } /* Add all values in lattices associated with NODE to the topological sort if they are not there yet. */ static void add_all_node_vals_to_toposort (cgraph_node *node, ipa_topo_info *topo) { struct ipa_node_params *info = IPA_NODE_REF (node); int i, count = ipa_get_param_count (info); for (i = 0; i < count ; i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); ipcp_lattice *lat = &plats->itself; struct ipcp_agg_lattice *aglat; if (!lat->bottom) { ipcp_value *val; for (val = lat->values; val; val = val->next) topo->constants.add_val (val); } if (!plats->aggs_bottom) for (aglat = plats->aggs; aglat; aglat = aglat->next) if (!aglat->bottom) { ipcp_value *val; for (val = aglat->values; val; val = val->next) topo->constants.add_val (val); } ipcp_lattice *ctxlat = &plats->ctxlat; if (!ctxlat->bottom) { ipcp_value *ctxval; for (ctxval = ctxlat->values; ctxval; ctxval = ctxval->next) topo->contexts.add_val (ctxval); } } } /* One pass of constants propagation along the call graph edges, from callers to callees (requires topological ordering in TOPO), iterate over strongly connected components. */ static void propagate_constants_topo (struct ipa_topo_info *topo) { int i; for (i = topo->nnodes - 1; i >= 0; i--) { unsigned j; struct cgraph_node *v, *node = topo->order[i]; vec cycle_nodes = ipa_get_nodes_in_cycle (node); /* First, iteratively propagate within the strongly connected component until all lattices stabilize. */ FOR_EACH_VEC_ELT (cycle_nodes, j, v) if (v->has_gimple_body_p ()) push_node_to_stack (topo, v); v = pop_node_from_stack (topo); while (v) { struct cgraph_edge *cs; for (cs = v->callees; cs; cs = cs->next_callee) if (ipa_edge_within_scc (cs) && propagate_constants_accross_call (cs)) push_node_to_stack (topo, cs->callee); v = pop_node_from_stack (topo); } /* Afterwards, propagate along edges leading out of the SCC, calculates the local effects of the discovered constants and all valid values to their topological sort. */ FOR_EACH_VEC_ELT (cycle_nodes, j, v) if (v->has_gimple_body_p ()) { struct cgraph_edge *cs; estimate_local_effects (v); add_all_node_vals_to_toposort (v, topo); for (cs = v->callees; cs; cs = cs->next_callee) if (!ipa_edge_within_scc (cs)) propagate_constants_accross_call (cs); } cycle_nodes.release (); } } /* Return the sum of A and B if none of them is bigger than INT_MAX/2, return the bigger one if otherwise. */ static int safe_add (int a, int b) { if (a > INT_MAX/2 || b > INT_MAX/2) return a > b ? a : b; else return a + b; } /* Propagate the estimated effects of individual values along the topological from the dependent values to those they depend on. */ template void value_topo_info::propagate_effects () { ipcp_value *base; for (base = values_topo; base; base = base->topo_next) { ipcp_value_source *src; ipcp_value *val; int time = 0, size = 0; for (val = base; val; val = val->scc_next) { time = safe_add (time, val->local_time_benefit + val->prop_time_benefit); size = safe_add (size, val->local_size_cost + val->prop_size_cost); } for (val = base; val; val = val->scc_next) for (src = val->sources; src; src = src->next) if (src->val && src->cs->maybe_hot_p ()) { src->val->prop_time_benefit = safe_add (time, src->val->prop_time_benefit); src->val->prop_size_cost = safe_add (size, src->val->prop_size_cost); } } } /* Propagate constants, polymorphic contexts and their effects from the summaries interprocedurally. */ static void ipcp_propagate_stage (struct ipa_topo_info *topo) { struct cgraph_node *node; if (dump_file) fprintf (dump_file, "\n Propagating constants:\n\n"); if (in_lto_p) ipa_update_after_lto_read (); FOR_EACH_DEFINED_FUNCTION (node) { struct ipa_node_params *info = IPA_NODE_REF (node); determine_versionability (node); if (node->has_gimple_body_p ()) { info->lattices = XCNEWVEC (struct ipcp_param_lattices, ipa_get_param_count (info)); initialize_node_lattices (node); } if (node->definition && !node->alias) overall_size += inline_summaries->get (node)->self_size; if (node->count > max_count) max_count = node->count; } max_new_size = overall_size; if (max_new_size < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS)) max_new_size = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS); max_new_size += max_new_size * PARAM_VALUE (PARAM_IPCP_UNIT_GROWTH) / 100 + 1; if (dump_file) fprintf (dump_file, "\noverall_size: %li, max_new_size: %li\n", overall_size, max_new_size); propagate_constants_topo (topo); #ifdef ENABLE_CHECKING ipcp_verify_propagated_values (); #endif topo->constants.propagate_effects (); topo->contexts.propagate_effects (); if (dump_file) { fprintf (dump_file, "\nIPA lattices after all propagation:\n"); print_all_lattices (dump_file, (dump_flags & TDF_DETAILS), true); } } /* Discover newly direct outgoing edges from NODE which is a new clone with known KNOWN_CSTS and make them direct. */ static void ipcp_discover_new_direct_edges (struct cgraph_node *node, vec known_csts, vec known_contexts, struct ipa_agg_replacement_value *aggvals) { struct cgraph_edge *ie, *next_ie; bool found = false; for (ie = node->indirect_calls; ie; ie = next_ie) { tree target; bool speculative; next_ie = ie->next_callee; target = ipa_get_indirect_edge_target_1 (ie, known_csts, known_contexts, vNULL, aggvals, &speculative); if (target) { bool agg_contents = ie->indirect_info->agg_contents; bool polymorphic = ie->indirect_info->polymorphic; int param_index = ie->indirect_info->param_index; struct cgraph_edge *cs = ipa_make_edge_direct_to_target (ie, target, speculative); found = true; if (cs && !agg_contents && !polymorphic) { struct ipa_node_params *info = IPA_NODE_REF (node); int c = ipa_get_controlled_uses (info, param_index); if (c != IPA_UNDESCRIBED_USE) { struct ipa_ref *to_del; c--; ipa_set_controlled_uses (info, param_index, c); if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " controlled uses count of param " "%i bumped down to %i\n", param_index, c); if (c == 0 && (to_del = node->find_reference (cs->callee, NULL, 0))) { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " and even removing its " "cloning-created reference\n"); to_del->remove_reference (); } } } } } /* Turning calls to direct calls will improve overall summary. */ if (found) inline_update_overall_summary (node); } /* Vector of pointers which for linked lists of clones of an original crgaph edge. */ static vec next_edge_clone; static vec prev_edge_clone; static inline void grow_edge_clone_vectors (void) { if (next_edge_clone.length () <= (unsigned) symtab->edges_max_uid) next_edge_clone.safe_grow_cleared (symtab->edges_max_uid + 1); if (prev_edge_clone.length () <= (unsigned) symtab->edges_max_uid) prev_edge_clone.safe_grow_cleared (symtab->edges_max_uid + 1); } /* Edge duplication hook to grow the appropriate linked list in next_edge_clone. */ static void ipcp_edge_duplication_hook (struct cgraph_edge *src, struct cgraph_edge *dst, void *) { grow_edge_clone_vectors (); struct cgraph_edge *old_next = next_edge_clone[src->uid]; if (old_next) prev_edge_clone[old_next->uid] = dst; prev_edge_clone[dst->uid] = src; next_edge_clone[dst->uid] = old_next; next_edge_clone[src->uid] = dst; } /* Hook that is called by cgraph.c when an edge is removed. */ static void ipcp_edge_removal_hook (struct cgraph_edge *cs, void *) { grow_edge_clone_vectors (); struct cgraph_edge *prev = prev_edge_clone[cs->uid]; struct cgraph_edge *next = next_edge_clone[cs->uid]; if (prev) next_edge_clone[prev->uid] = next; if (next) prev_edge_clone[next->uid] = prev; } /* See if NODE is a clone with a known aggregate value at a given OFFSET of a parameter with the given INDEX. */ static tree get_clone_agg_value (struct cgraph_node *node, HOST_WIDE_INT offset, int index) { struct ipa_agg_replacement_value *aggval; aggval = ipa_get_agg_replacements_for_node (node); while (aggval) { if (aggval->offset == offset && aggval->index == index) return aggval->value; aggval = aggval->next; } return NULL_TREE; } /* Return true is NODE is DEST or its clone for all contexts. */ static bool same_node_or_its_all_contexts_clone_p (cgraph_node *node, cgraph_node *dest) { if (node == dest) return true; struct ipa_node_params *info = IPA_NODE_REF (node); return info->is_all_contexts_clone && info->ipcp_orig_node == dest; } /* Return true if edge CS does bring about the value described by SRC to node DEST or its clone for all contexts. */ static bool cgraph_edge_brings_value_p (cgraph_edge *cs, ipcp_value_source *src, cgraph_node *dest) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); enum availability availability; cgraph_node *real_dest = cs->callee->function_symbol (&availability); if (!same_node_or_its_all_contexts_clone_p (real_dest, dest) || availability <= AVAIL_INTERPOSABLE || caller_info->node_dead) return false; if (!src->val) return true; if (caller_info->ipcp_orig_node) { tree t; if (src->offset == -1) t = caller_info->known_csts[src->index]; else t = get_clone_agg_value (cs->caller, src->offset, src->index); return (t != NULL_TREE && values_equal_for_ipcp_p (src->val->value, t)); } else { struct ipcp_agg_lattice *aglat; struct ipcp_param_lattices *plats = ipa_get_parm_lattices (caller_info, src->index); if (src->offset == -1) return (plats->itself.is_single_const () && values_equal_for_ipcp_p (src->val->value, plats->itself.values->value)); else { if (plats->aggs_bottom || plats->aggs_contain_variable) return false; for (aglat = plats->aggs; aglat; aglat = aglat->next) if (aglat->offset == src->offset) return (aglat->is_single_const () && values_equal_for_ipcp_p (src->val->value, aglat->values->value)); } return false; } } /* Return true if edge CS does bring about the value described by SRC to node DEST or its clone for all contexts. */ static bool cgraph_edge_brings_value_p (cgraph_edge *cs, ipcp_value_source *src, cgraph_node *dest) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); cgraph_node *real_dest = cs->callee->function_symbol (); if (!same_node_or_its_all_contexts_clone_p (real_dest, dest) || caller_info->node_dead) return false; if (!src->val) return true; if (caller_info->ipcp_orig_node) return (caller_info->known_contexts.length () > (unsigned) src->index) && values_equal_for_ipcp_p (src->val->value, caller_info->known_contexts[src->index]); struct ipcp_param_lattices *plats = ipa_get_parm_lattices (caller_info, src->index); return plats->ctxlat.is_single_const () && values_equal_for_ipcp_p (src->val->value, plats->ctxlat.values->value); } /* Get the next clone in the linked list of clones of an edge. */ static inline struct cgraph_edge * get_next_cgraph_edge_clone (struct cgraph_edge *cs) { return next_edge_clone[cs->uid]; } /* Given VAL that is intended for DEST, iterate over all its sources and if they still hold, add their edge frequency and their number into *FREQUENCY and *CALLER_COUNT respectively. */ template static bool get_info_about_necessary_edges (ipcp_value *val, cgraph_node *dest, int *freq_sum, gcov_type *count_sum, int *caller_count) { ipcp_value_source *src; int freq = 0, count = 0; gcov_type cnt = 0; bool hot = false; for (src = val->sources; src; src = src->next) { struct cgraph_edge *cs = src->cs; while (cs) { if (cgraph_edge_brings_value_p (cs, src, dest)) { count++; freq += cs->frequency; cnt += cs->count; hot |= cs->maybe_hot_p (); } cs = get_next_cgraph_edge_clone (cs); } } *freq_sum = freq; *count_sum = cnt; *caller_count = count; return hot; } /* Return a vector of incoming edges that do bring value VAL to node DEST. It is assumed their number is known and equal to CALLER_COUNT. */ template static vec gather_edges_for_value (ipcp_value *val, cgraph_node *dest, int caller_count) { ipcp_value_source *src; vec ret; ret.create (caller_count); for (src = val->sources; src; src = src->next) { struct cgraph_edge *cs = src->cs; while (cs) { if (cgraph_edge_brings_value_p (cs, src, dest)) ret.quick_push (cs); cs = get_next_cgraph_edge_clone (cs); } } return ret; } /* Construct a replacement map for a know VALUE for a formal parameter PARAM. Return it or NULL if for some reason it cannot be created. */ static struct ipa_replace_map * get_replacement_map (struct ipa_node_params *info, tree value, int parm_num) { struct ipa_replace_map *replace_map; replace_map = ggc_alloc (); if (dump_file) { fprintf (dump_file, " replacing "); ipa_dump_param (dump_file, info, parm_num); fprintf (dump_file, " with const "); print_generic_expr (dump_file, value, 0); fprintf (dump_file, "\n"); } replace_map->old_tree = NULL; replace_map->parm_num = parm_num; replace_map->new_tree = value; replace_map->replace_p = true; replace_map->ref_p = false; return replace_map; } /* Dump new profiling counts */ static void dump_profile_updates (struct cgraph_node *orig_node, struct cgraph_node *new_node) { struct cgraph_edge *cs; fprintf (dump_file, " setting count of the specialized node to " HOST_WIDE_INT_PRINT_DEC "\n", (HOST_WIDE_INT) new_node->count); for (cs = new_node->callees; cs ; cs = cs->next_callee) fprintf (dump_file, " edge to %s has count " HOST_WIDE_INT_PRINT_DEC "\n", cs->callee->name (), (HOST_WIDE_INT) cs->count); fprintf (dump_file, " setting count of the original node to " HOST_WIDE_INT_PRINT_DEC "\n", (HOST_WIDE_INT) orig_node->count); for (cs = orig_node->callees; cs ; cs = cs->next_callee) fprintf (dump_file, " edge to %s is left with " HOST_WIDE_INT_PRINT_DEC "\n", cs->callee->name (), (HOST_WIDE_INT) cs->count); } /* After a specialized NEW_NODE version of ORIG_NODE has been created, update their profile information to reflect this. */ static void update_profiling_info (struct cgraph_node *orig_node, struct cgraph_node *new_node) { struct cgraph_edge *cs; struct caller_statistics stats; gcov_type new_sum, orig_sum; gcov_type remainder, orig_node_count = orig_node->count; if (orig_node_count == 0) return; init_caller_stats (&stats); orig_node->call_for_symbol_thunks_and_aliases (gather_caller_stats, &stats, false); orig_sum = stats.count_sum; init_caller_stats (&stats); new_node->call_for_symbol_thunks_and_aliases (gather_caller_stats, &stats, false); new_sum = stats.count_sum; if (orig_node_count < orig_sum + new_sum) { if (dump_file) fprintf (dump_file, " Problem: node %s/%i has too low count " HOST_WIDE_INT_PRINT_DEC " while the sum of incoming " "counts is " HOST_WIDE_INT_PRINT_DEC "\n", orig_node->name (), orig_node->order, (HOST_WIDE_INT) orig_node_count, (HOST_WIDE_INT) (orig_sum + new_sum)); orig_node_count = (orig_sum + new_sum) * 12 / 10; if (dump_file) fprintf (dump_file, " proceeding by pretending it was " HOST_WIDE_INT_PRINT_DEC "\n", (HOST_WIDE_INT) orig_node_count); } new_node->count = new_sum; remainder = orig_node_count - new_sum; orig_node->count = remainder; for (cs = new_node->callees; cs ; cs = cs->next_callee) if (cs->frequency) cs->count = apply_probability (cs->count, GCOV_COMPUTE_SCALE (new_sum, orig_node_count)); else cs->count = 0; for (cs = orig_node->callees; cs ; cs = cs->next_callee) cs->count = apply_probability (cs->count, GCOV_COMPUTE_SCALE (remainder, orig_node_count)); if (dump_file) dump_profile_updates (orig_node, new_node); } /* Update the respective profile of specialized NEW_NODE and the original ORIG_NODE after additional edges with cumulative count sum REDIRECTED_SUM have been redirected to the specialized version. */ static void update_specialized_profile (struct cgraph_node *new_node, struct cgraph_node *orig_node, gcov_type redirected_sum) { struct cgraph_edge *cs; gcov_type new_node_count, orig_node_count = orig_node->count; if (dump_file) fprintf (dump_file, " the sum of counts of redirected edges is " HOST_WIDE_INT_PRINT_DEC "\n", (HOST_WIDE_INT) redirected_sum); if (orig_node_count == 0) return; gcc_assert (orig_node_count >= redirected_sum); new_node_count = new_node->count; new_node->count += redirected_sum; orig_node->count -= redirected_sum; for (cs = new_node->callees; cs ; cs = cs->next_callee) if (cs->frequency) cs->count += apply_probability (cs->count, GCOV_COMPUTE_SCALE (redirected_sum, new_node_count)); else cs->count = 0; for (cs = orig_node->callees; cs ; cs = cs->next_callee) { gcov_type dec = apply_probability (cs->count, GCOV_COMPUTE_SCALE (redirected_sum, orig_node_count)); if (dec < cs->count) cs->count -= dec; else cs->count = 0; } if (dump_file) dump_profile_updates (orig_node, new_node); } /* Create a specialized version of NODE with known constants in KNOWN_CSTS, known contexts in KNOWN_CONTEXTS and known aggregate values in AGGVALS and redirect all edges in CALLERS to it. */ static struct cgraph_node * create_specialized_node (struct cgraph_node *node, vec known_csts, vec known_contexts, struct ipa_agg_replacement_value *aggvals, vec callers) { struct ipa_node_params *new_info, *info = IPA_NODE_REF (node); vec *replace_trees = NULL; struct ipa_agg_replacement_value *av; struct cgraph_node *new_node; int i, count = ipa_get_param_count (info); bitmap args_to_skip; gcc_assert (!info->ipcp_orig_node); if (node->local.can_change_signature) { args_to_skip = BITMAP_GGC_ALLOC (); for (i = 0; i < count; i++) { tree t = known_csts[i]; if (t || !ipa_is_param_used (info, i)) bitmap_set_bit (args_to_skip, i); } } else { args_to_skip = NULL; if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " cannot change function signature\n"); } for (i = 0; i < count ; i++) { tree t = known_csts[i]; if (t) { struct ipa_replace_map *replace_map; gcc_checking_assert (TREE_CODE (t) != TREE_BINFO); replace_map = get_replacement_map (info, t, i); if (replace_map) vec_safe_push (replace_trees, replace_map); } } new_node = node->create_virtual_clone (callers, replace_trees, args_to_skip, "constprop"); ipa_set_node_agg_value_chain (new_node, aggvals); for (av = aggvals; av; av = av->next) new_node->maybe_create_reference (av->value, IPA_REF_ADDR, NULL); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " the new node is %s/%i.\n", new_node->name (), new_node->order); if (known_contexts.exists ()) { for (i = 0; i < count ; i++) if (!known_contexts[i].useless_p ()) { fprintf (dump_file, " known ctx %i is ", i); known_contexts[i].dump (dump_file); } } if (aggvals) ipa_dump_agg_replacement_values (dump_file, aggvals); } ipa_check_create_node_params (); update_profiling_info (node, new_node); new_info = IPA_NODE_REF (new_node); new_info->ipcp_orig_node = node; new_info->known_csts = known_csts; new_info->known_contexts = known_contexts; ipcp_discover_new_direct_edges (new_node, known_csts, known_contexts, aggvals); callers.release (); return new_node; } /* Given a NODE, and a subset of its CALLERS, try to populate blanks slots in KNOWN_CSTS with constants that are also known for all of the CALLERS. */ static void find_more_scalar_values_for_callers_subset (struct cgraph_node *node, vec known_csts, vec callers) { struct ipa_node_params *info = IPA_NODE_REF (node); int i, count = ipa_get_param_count (info); for (i = 0; i < count ; i++) { struct cgraph_edge *cs; tree newval = NULL_TREE; int j; bool first = true; if (ipa_get_scalar_lat (info, i)->bottom || known_csts[i]) continue; FOR_EACH_VEC_ELT (callers, j, cs) { struct ipa_jump_func *jump_func; tree t; if (i >= ipa_get_cs_argument_count (IPA_EDGE_REF (cs))) { newval = NULL_TREE; break; } jump_func = ipa_get_ith_jump_func (IPA_EDGE_REF (cs), i); t = ipa_value_from_jfunc (IPA_NODE_REF (cs->caller), jump_func); if (!t || (newval && !values_equal_for_ipcp_p (t, newval)) || (!first && !newval)) { newval = NULL_TREE; break; } else newval = t; first = false; } if (newval) { if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " adding an extra known scalar value "); print_ipcp_constant_value (dump_file, newval); fprintf (dump_file, " for "); ipa_dump_param (dump_file, info, i); fprintf (dump_file, "\n"); } known_csts[i] = newval; } } } /* Given a NODE and a subset of its CALLERS, try to populate plank slots in KNOWN_CONTEXTS with polymorphic contexts that are also known for all of the CALLERS. */ static void find_more_contexts_for_caller_subset (cgraph_node *node, vec *known_contexts, vec callers) { ipa_node_params *info = IPA_NODE_REF (node); int i, count = ipa_get_param_count (info); for (i = 0; i < count ; i++) { cgraph_edge *cs; if (ipa_get_poly_ctx_lat (info, i)->bottom || (known_contexts->exists () && !(*known_contexts)[i].useless_p ())) continue; ipa_polymorphic_call_context newval; bool first = true; int j; FOR_EACH_VEC_ELT (callers, j, cs) { if (i >= ipa_get_cs_argument_count (IPA_EDGE_REF (cs))) return; ipa_jump_func *jfunc = ipa_get_ith_jump_func (IPA_EDGE_REF (cs), i); ipa_polymorphic_call_context ctx; ctx = ipa_context_from_jfunc (IPA_NODE_REF (cs->caller), cs, i, jfunc); if (first) { newval = ctx; first = false; } else newval.meet_with (ctx); if (newval.useless_p ()) break; } if (!newval.useless_p ()) { if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " adding an extra known polymorphic " "context "); print_ipcp_constant_value (dump_file, newval); fprintf (dump_file, " for "); ipa_dump_param (dump_file, info, i); fprintf (dump_file, "\n"); } if (!known_contexts->exists ()) known_contexts->safe_grow_cleared (ipa_get_param_count (info)); (*known_contexts)[i] = newval; } } } /* Go through PLATS and create a vector of values consisting of values and offsets (minus OFFSET) of lattices that contain only a single value. */ static vec copy_plats_to_inter (struct ipcp_param_lattices *plats, HOST_WIDE_INT offset) { vec res = vNULL; if (!plats->aggs || plats->aggs_contain_variable || plats->aggs_bottom) return vNULL; for (struct ipcp_agg_lattice *aglat = plats->aggs; aglat; aglat = aglat->next) if (aglat->is_single_const ()) { struct ipa_agg_jf_item ti; ti.offset = aglat->offset - offset; ti.value = aglat->values->value; res.safe_push (ti); } return res; } /* Intersect all values in INTER with single value lattices in PLATS (while subtracting OFFSET). */ static void intersect_with_plats (struct ipcp_param_lattices *plats, vec *inter, HOST_WIDE_INT offset) { struct ipcp_agg_lattice *aglat; struct ipa_agg_jf_item *item; int k; if (!plats->aggs || plats->aggs_contain_variable || plats->aggs_bottom) { inter->release (); return; } aglat = plats->aggs; FOR_EACH_VEC_ELT (*inter, k, item) { bool found = false; if (!item->value) continue; while (aglat) { if (aglat->offset - offset > item->offset) break; if (aglat->offset - offset == item->offset) { gcc_checking_assert (item->value); if (values_equal_for_ipcp_p (item->value, aglat->values->value)) found = true; break; } aglat = aglat->next; } if (!found) item->value = NULL_TREE; } } /* Copy agggregate replacement values of NODE (which is an IPA-CP clone) to the vector result while subtracting OFFSET from the individual value offsets. */ static vec agg_replacements_to_vector (struct cgraph_node *node, int index, HOST_WIDE_INT offset) { struct ipa_agg_replacement_value *av; vec res = vNULL; for (av = ipa_get_agg_replacements_for_node (node); av; av = av->next) if (av->index == index && (av->offset - offset) >= 0) { struct ipa_agg_jf_item item; gcc_checking_assert (av->value); item.offset = av->offset - offset; item.value = av->value; res.safe_push (item); } return res; } /* Intersect all values in INTER with those that we have already scheduled to be replaced in parameter number INDEX of NODE, which is an IPA-CP clone (while subtracting OFFSET). */ static void intersect_with_agg_replacements (struct cgraph_node *node, int index, vec *inter, HOST_WIDE_INT offset) { struct ipa_agg_replacement_value *srcvals; struct ipa_agg_jf_item *item; int i; srcvals = ipa_get_agg_replacements_for_node (node); if (!srcvals) { inter->release (); return; } FOR_EACH_VEC_ELT (*inter, i, item) { struct ipa_agg_replacement_value *av; bool found = false; if (!item->value) continue; for (av = srcvals; av; av = av->next) { gcc_checking_assert (av->value); if (av->index == index && av->offset - offset == item->offset) { if (values_equal_for_ipcp_p (item->value, av->value)) found = true; break; } } if (!found) item->value = NULL_TREE; } } /* Intersect values in INTER with aggregate values that come along edge CS to parameter number INDEX and return it. If INTER does not actually exist yet, copy all incoming values to it. If we determine we ended up with no values whatsoever, return a released vector. */ static vec intersect_aggregates_with_edge (struct cgraph_edge *cs, int index, vec inter) { struct ipa_jump_func *jfunc; jfunc = ipa_get_ith_jump_func (IPA_EDGE_REF (cs), index); if (jfunc->type == IPA_JF_PASS_THROUGH && ipa_get_jf_pass_through_operation (jfunc) == NOP_EXPR) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); int src_idx = ipa_get_jf_pass_through_formal_id (jfunc); if (caller_info->ipcp_orig_node) { struct cgraph_node *orig_node = caller_info->ipcp_orig_node; struct ipcp_param_lattices *orig_plats; orig_plats = ipa_get_parm_lattices (IPA_NODE_REF (orig_node), src_idx); if (agg_pass_through_permissible_p (orig_plats, jfunc)) { if (!inter.exists ()) inter = agg_replacements_to_vector (cs->caller, src_idx, 0); else intersect_with_agg_replacements (cs->caller, src_idx, &inter, 0); } else { inter.release (); return vNULL; } } else { struct ipcp_param_lattices *src_plats; src_plats = ipa_get_parm_lattices (caller_info, src_idx); if (agg_pass_through_permissible_p (src_plats, jfunc)) { /* Currently we do not produce clobber aggregate jump functions, adjust when we do. */ gcc_checking_assert (!jfunc->agg.items); if (!inter.exists ()) inter = copy_plats_to_inter (src_plats, 0); else intersect_with_plats (src_plats, &inter, 0); } else { inter.release (); return vNULL; } } } else if (jfunc->type == IPA_JF_ANCESTOR && ipa_get_jf_ancestor_agg_preserved (jfunc)) { struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller); int src_idx = ipa_get_jf_ancestor_formal_id (jfunc); struct ipcp_param_lattices *src_plats; HOST_WIDE_INT delta = ipa_get_jf_ancestor_offset (jfunc); if (caller_info->ipcp_orig_node) { if (!inter.exists ()) inter = agg_replacements_to_vector (cs->caller, src_idx, delta); else intersect_with_agg_replacements (cs->caller, src_idx, &inter, delta); } else { src_plats = ipa_get_parm_lattices (caller_info, src_idx);; /* Currently we do not produce clobber aggregate jump functions, adjust when we do. */ gcc_checking_assert (!src_plats->aggs || !jfunc->agg.items); if (!inter.exists ()) inter = copy_plats_to_inter (src_plats, delta); else intersect_with_plats (src_plats, &inter, delta); } } else if (jfunc->agg.items) { struct ipa_agg_jf_item *item; int k; if (!inter.exists ()) for (unsigned i = 0; i < jfunc->agg.items->length (); i++) inter.safe_push ((*jfunc->agg.items)[i]); else FOR_EACH_VEC_ELT (inter, k, item) { int l = 0; bool found = false;; if (!item->value) continue; while ((unsigned) l < jfunc->agg.items->length ()) { struct ipa_agg_jf_item *ti; ti = &(*jfunc->agg.items)[l]; if (ti->offset > item->offset) break; if (ti->offset == item->offset) { gcc_checking_assert (ti->value); if (values_equal_for_ipcp_p (item->value, ti->value)) found = true; break; } l++; } if (!found) item->value = NULL; } } else { inter.release (); return vec(); } return inter; } /* Look at edges in CALLERS and collect all known aggregate values that arrive from all of them. */ static struct ipa_agg_replacement_value * find_aggregate_values_for_callers_subset (struct cgraph_node *node, vec callers) { struct ipa_node_params *dest_info = IPA_NODE_REF (node); struct ipa_agg_replacement_value *res; struct ipa_agg_replacement_value **tail = &res; struct cgraph_edge *cs; int i, j, count = ipa_get_param_count (dest_info); FOR_EACH_VEC_ELT (callers, j, cs) { int c = ipa_get_cs_argument_count (IPA_EDGE_REF (cs)); if (c < count) count = c; } for (i = 0; i < count ; i++) { struct cgraph_edge *cs; vec inter = vNULL; struct ipa_agg_jf_item *item; struct ipcp_param_lattices *plats = ipa_get_parm_lattices (dest_info, i); int j; /* Among other things, the following check should deal with all by_ref mismatches. */ if (plats->aggs_bottom) continue; FOR_EACH_VEC_ELT (callers, j, cs) { inter = intersect_aggregates_with_edge (cs, i, inter); if (!inter.exists ()) goto next_param; } FOR_EACH_VEC_ELT (inter, j, item) { struct ipa_agg_replacement_value *v; if (!item->value) continue; v = ggc_alloc (); v->index = i; v->offset = item->offset; v->value = item->value; v->by_ref = plats->aggs_by_ref; *tail = v; tail = &v->next; } next_param: if (inter.exists ()) inter.release (); } *tail = NULL; return res; } /* Turn KNOWN_AGGS into a list of aggreate replacement values. */ static struct ipa_agg_replacement_value * known_aggs_to_agg_replacement_list (vec known_aggs) { struct ipa_agg_replacement_value *res; struct ipa_agg_replacement_value **tail = &res; struct ipa_agg_jump_function *aggjf; struct ipa_agg_jf_item *item; int i, j; FOR_EACH_VEC_ELT (known_aggs, i, aggjf) FOR_EACH_VEC_SAFE_ELT (aggjf->items, j, item) { struct ipa_agg_replacement_value *v; v = ggc_alloc (); v->index = i; v->offset = item->offset; v->value = item->value; v->by_ref = aggjf->by_ref; *tail = v; tail = &v->next; } *tail = NULL; return res; } /* Determine whether CS also brings all scalar values that the NODE is specialized for. */ static bool cgraph_edge_brings_all_scalars_for_node (struct cgraph_edge *cs, struct cgraph_node *node) { struct ipa_node_params *dest_info = IPA_NODE_REF (node); int count = ipa_get_param_count (dest_info); struct ipa_node_params *caller_info; struct ipa_edge_args *args; int i; caller_info = IPA_NODE_REF (cs->caller); args = IPA_EDGE_REF (cs); for (i = 0; i < count; i++) { struct ipa_jump_func *jump_func; tree val, t; val = dest_info->known_csts[i]; if (!val) continue; if (i >= ipa_get_cs_argument_count (args)) return false; jump_func = ipa_get_ith_jump_func (args, i); t = ipa_value_from_jfunc (caller_info, jump_func); if (!t || !values_equal_for_ipcp_p (val, t)) return false; } return true; } /* Determine whether CS also brings all aggregate values that NODE is specialized for. */ static bool cgraph_edge_brings_all_agg_vals_for_node (struct cgraph_edge *cs, struct cgraph_node *node) { struct ipa_node_params *orig_caller_info = IPA_NODE_REF (cs->caller); struct ipa_node_params *orig_node_info; struct ipa_agg_replacement_value *aggval; int i, ec, count; aggval = ipa_get_agg_replacements_for_node (node); if (!aggval) return true; count = ipa_get_param_count (IPA_NODE_REF (node)); ec = ipa_get_cs_argument_count (IPA_EDGE_REF (cs)); if (ec < count) for (struct ipa_agg_replacement_value *av = aggval; av; av = av->next) if (aggval->index >= ec) return false; orig_node_info = IPA_NODE_REF (IPA_NODE_REF (node)->ipcp_orig_node); if (orig_caller_info->ipcp_orig_node) orig_caller_info = IPA_NODE_REF (orig_caller_info->ipcp_orig_node); for (i = 0; i < count; i++) { static vec values = vec(); struct ipcp_param_lattices *plats; bool interesting = false; for (struct ipa_agg_replacement_value *av = aggval; av; av = av->next) if (aggval->index == i) { interesting = true; break; } if (!interesting) continue; plats = ipa_get_parm_lattices (orig_node_info, aggval->index); if (plats->aggs_bottom) return false; values = intersect_aggregates_with_edge (cs, i, values); if (!values.exists ()) return false; for (struct ipa_agg_replacement_value *av = aggval; av; av = av->next) if (aggval->index == i) { struct ipa_agg_jf_item *item; int j; bool found = false; FOR_EACH_VEC_ELT (values, j, item) if (item->value && item->offset == av->offset && values_equal_for_ipcp_p (item->value, av->value)) { found = true; break; } if (!found) { values.release (); return false; } } } return true; } /* Given an original NODE and a VAL for which we have already created a specialized clone, look whether there are incoming edges that still lead into the old node but now also bring the requested value and also conform to all other criteria such that they can be redirected the the special node. This function can therefore redirect the final edge in a SCC. */ template static void perhaps_add_new_callers (cgraph_node *node, ipcp_value *val) { ipcp_value_source *src; gcov_type redirected_sum = 0; for (src = val->sources; src; src = src->next) { struct cgraph_edge *cs = src->cs; while (cs) { if (cgraph_edge_brings_value_p (cs, src, node) && cgraph_edge_brings_all_scalars_for_node (cs, val->spec_node) && cgraph_edge_brings_all_agg_vals_for_node (cs, val->spec_node)) { if (dump_file) fprintf (dump_file, " - adding an extra caller %s/%i" " of %s/%i\n", xstrdup_for_dump (cs->caller->name ()), cs->caller->order, xstrdup_for_dump (val->spec_node->name ()), val->spec_node->order); cs->redirect_callee_duplicating_thunks (val->spec_node); val->spec_node->expand_all_artificial_thunks (); redirected_sum += cs->count; } cs = get_next_cgraph_edge_clone (cs); } } if (redirected_sum) update_specialized_profile (val->spec_node, node, redirected_sum); } /* Return true if KNOWN_CONTEXTS contain at least one useful context. */ static bool known_contexts_useful_p (vec known_contexts) { ipa_polymorphic_call_context *ctx; int i; FOR_EACH_VEC_ELT (known_contexts, i, ctx) if (!ctx->useless_p ()) return true; return false; } /* Return a copy of KNOWN_CSTS if it is not empty, otherwise return vNULL. */ static vec copy_useful_known_contexts (vec known_contexts) { if (known_contexts_useful_p (known_contexts)) return known_contexts.copy (); else return vNULL; } /* Copy KNOWN_CSTS and modify the copy according to VAL and INDEX. If non-empty, replace KNOWN_CONTEXTS with its copy too. */ static void modify_known_vectors_with_val (vec *known_csts, vec *known_contexts, ipcp_value *val, int index) { *known_csts = known_csts->copy (); *known_contexts = copy_useful_known_contexts (*known_contexts); (*known_csts)[index] = val->value; } /* Replace KNOWN_CSTS with its copy. Also copy KNOWN_CONTEXTS and modify the copy according to VAL and INDEX. */ static void modify_known_vectors_with_val (vec *known_csts, vec *known_contexts, ipcp_value *val, int index) { *known_csts = known_csts->copy (); *known_contexts = known_contexts->copy (); (*known_contexts)[index] = val->value; } /* Return true if OFFSET indicates this was not an aggregate value or there is a replacement equivalent to VALUE, INDEX and OFFSET among those in the AGGVALS list. */ DEBUG_FUNCTION bool ipcp_val_agg_replacement_ok_p (ipa_agg_replacement_value *aggvals, int index, HOST_WIDE_INT offset, tree value) { if (offset == -1) return true; while (aggvals) { if (aggvals->index == index && aggvals->offset == offset && values_equal_for_ipcp_p (aggvals->value, value)) return true; aggvals = aggvals->next; } return false; } /* Return true if offset is minus one because source of a polymorphic contect cannot be an aggregate value. */ DEBUG_FUNCTION bool ipcp_val_agg_replacement_ok_p (ipa_agg_replacement_value *, int , HOST_WIDE_INT offset, ipa_polymorphic_call_context) { return offset == -1; } /* Decide wheter to create a special version of NODE for value VAL of parameter at the given INDEX. If OFFSET is -1, the value is for the parameter itself, otherwise it is stored at the given OFFSET of the parameter. KNOWN_CSTS, KNOWN_CONTEXTS and KNOWN_AGGS describe the other already known values. */ template static bool decide_about_value (struct cgraph_node *node, int index, HOST_WIDE_INT offset, ipcp_value *val, vec known_csts, vec known_contexts) { struct ipa_agg_replacement_value *aggvals; int freq_sum, caller_count; gcov_type count_sum; vec callers; if (val->spec_node) { perhaps_add_new_callers (node, val); return false; } else if (val->local_size_cost + overall_size > max_new_size) { if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " Ignoring candidate value because " "max_new_size would be reached with %li.\n", val->local_size_cost + overall_size); return false; } else if (!get_info_about_necessary_edges (val, node, &freq_sum, &count_sum, &caller_count)) return false; if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " - considering value "); print_ipcp_constant_value (dump_file, val->value); fprintf (dump_file, " for "); ipa_dump_param (dump_file, IPA_NODE_REF (node), index); if (offset != -1) fprintf (dump_file, ", offset: " HOST_WIDE_INT_PRINT_DEC, offset); fprintf (dump_file, " (caller_count: %i)\n", caller_count); } if (!good_cloning_opportunity_p (node, val->local_time_benefit, freq_sum, count_sum, val->local_size_cost) && !good_cloning_opportunity_p (node, val->local_time_benefit + val->prop_time_benefit, freq_sum, count_sum, val->local_size_cost + val->prop_size_cost)) return false; if (dump_file) fprintf (dump_file, " Creating a specialized node of %s/%i.\n", node->name (), node->order); callers = gather_edges_for_value (val, node, caller_count); if (offset == -1) modify_known_vectors_with_val (&known_csts, &known_contexts, val, index); else { known_csts = known_csts.copy (); known_contexts = copy_useful_known_contexts (known_contexts); } find_more_scalar_values_for_callers_subset (node, known_csts, callers); find_more_contexts_for_caller_subset (node, &known_contexts, callers); aggvals = find_aggregate_values_for_callers_subset (node, callers); gcc_checking_assert (ipcp_val_agg_replacement_ok_p (aggvals, index, offset, val->value)); val->spec_node = create_specialized_node (node, known_csts, known_contexts, aggvals, callers); overall_size += val->local_size_cost; /* TODO: If for some lattice there is only one other known value left, make a special node for it too. */ return true; } /* Decide whether and what specialized clones of NODE should be created. */ static bool decide_whether_version_node (struct cgraph_node *node) { struct ipa_node_params *info = IPA_NODE_REF (node); int i, count = ipa_get_param_count (info); vec known_csts; vec known_contexts; vec known_aggs = vNULL; bool ret = false; if (count == 0) return false; if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "\nEvaluating opportunities for %s/%i.\n", node->name (), node->order); gather_context_independent_values (info, &known_csts, &known_contexts, info->do_clone_for_all_contexts ? &known_aggs : NULL, NULL); for (i = 0; i < count ;i++) { struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); ipcp_lattice *lat = &plats->itself; ipcp_lattice *ctxlat = &plats->ctxlat; if (!lat->bottom && !known_csts[i]) { ipcp_value *val; for (val = lat->values; val; val = val->next) ret |= decide_about_value (node, i, -1, val, known_csts, known_contexts); } if (!plats->aggs_bottom) { struct ipcp_agg_lattice *aglat; ipcp_value *val; for (aglat = plats->aggs; aglat; aglat = aglat->next) if (!aglat->bottom && aglat->values /* If the following is false, the one value is in known_aggs. */ && (plats->aggs_contain_variable || !aglat->is_single_const ())) for (val = aglat->values; val; val = val->next) ret |= decide_about_value (node, i, aglat->offset, val, known_csts, known_contexts); } if (!ctxlat->bottom && known_contexts[i].useless_p ()) { ipcp_value *val; for (val = ctxlat->values; val; val = val->next) ret |= decide_about_value (node, i, -1, val, known_csts, known_contexts); } info = IPA_NODE_REF (node); } if (info->do_clone_for_all_contexts) { struct cgraph_node *clone; vec callers; if (dump_file) fprintf (dump_file, " - Creating a specialized node of %s/%i " "for all known contexts.\n", node->name (), node->order); callers = node->collect_callers (); if (!known_contexts_useful_p (known_contexts)) { known_contexts.release (); known_contexts = vNULL; } clone = create_specialized_node (node, known_csts, known_contexts, known_aggs_to_agg_replacement_list (known_aggs), callers); info = IPA_NODE_REF (node); info->do_clone_for_all_contexts = false; IPA_NODE_REF (clone)->is_all_contexts_clone = true; for (i = 0; i < count ; i++) vec_free (known_aggs[i].items); known_aggs.release (); ret = true; } else { known_csts.release (); known_contexts.release (); } return ret; } /* Transitively mark all callees of NODE within the same SCC as not dead. */ static void spread_undeadness (struct cgraph_node *node) { struct cgraph_edge *cs; for (cs = node->callees; cs; cs = cs->next_callee) if (ipa_edge_within_scc (cs)) { struct cgraph_node *callee; struct ipa_node_params *info; callee = cs->callee->function_symbol (NULL); info = IPA_NODE_REF (callee); if (info->node_dead) { info->node_dead = 0; spread_undeadness (callee); } } } /* Return true if NODE has a caller from outside of its SCC that is not dead. Worker callback for cgraph_for_node_and_aliases. */ static bool has_undead_caller_from_outside_scc_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) { struct cgraph_edge *cs; for (cs = node->callers; cs; cs = cs->next_caller) if (cs->caller->thunk.thunk_p && cs->caller->call_for_symbol_thunks_and_aliases (has_undead_caller_from_outside_scc_p, NULL, true)) return true; else if (!ipa_edge_within_scc (cs) && !IPA_NODE_REF (cs->caller)->node_dead) return true; return false; } /* Identify nodes within the same SCC as NODE which are no longer needed because of new clones and will be removed as unreachable. */ static void identify_dead_nodes (struct cgraph_node *node) { struct cgraph_node *v; for (v = node; v ; v = ((struct ipa_dfs_info *) v->aux)->next_cycle) if (v->will_be_removed_from_program_if_no_direct_calls_p () && !v->call_for_symbol_thunks_and_aliases (has_undead_caller_from_outside_scc_p, NULL, true)) IPA_NODE_REF (v)->node_dead = 1; for (v = node; v ; v = ((struct ipa_dfs_info *) v->aux)->next_cycle) if (!IPA_NODE_REF (v)->node_dead) spread_undeadness (v); if (dump_file && (dump_flags & TDF_DETAILS)) { for (v = node; v ; v = ((struct ipa_dfs_info *) v->aux)->next_cycle) if (IPA_NODE_REF (v)->node_dead) fprintf (dump_file, " Marking node as dead: %s/%i.\n", v->name (), v->order); } } /* The decision stage. Iterate over the topological order of call graph nodes TOPO and make specialized clones if deemed beneficial. */ static void ipcp_decision_stage (struct ipa_topo_info *topo) { int i; if (dump_file) fprintf (dump_file, "\nIPA decision stage:\n\n"); for (i = topo->nnodes - 1; i >= 0; i--) { struct cgraph_node *node = topo->order[i]; bool change = false, iterate = true; while (iterate) { struct cgraph_node *v; iterate = false; for (v = node; v ; v = ((struct ipa_dfs_info *) v->aux)->next_cycle) if (v->has_gimple_body_p () && ipcp_versionable_function_p (v)) iterate |= decide_whether_version_node (v); change |= iterate; } if (change) identify_dead_nodes (node); } } /* Look up all alignment information that we have discovered and copy it over to the transformation summary. */ static void ipcp_store_alignment_results (void) { cgraph_node *node; FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) { ipa_node_params *info = IPA_NODE_REF (node); bool dumped_sth = false; bool found_useful_result = false; if (info->ipcp_orig_node) info = IPA_NODE_REF (info->ipcp_orig_node); unsigned count = ipa_get_param_count (info); for (unsigned i = 0; i < count ; i++) { ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); if (plats->alignment.known && plats->alignment.align > 0) { found_useful_result = true; break; } } if (!found_useful_result) continue; ipcp_grow_transformations_if_necessary (); ipcp_transformation_summary *ts = ipcp_get_transformation_summary (node); vec_safe_reserve_exact (ts->alignments, count); for (unsigned i = 0; i < count ; i++) { ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i); if (plats->alignment.align == 0) plats->alignment.known = false; ts->alignments->quick_push (plats->alignment); if (!dump_file || !plats->alignment.known) continue; if (!dumped_sth) { fprintf (dump_file, "Propagated alignment info for function %s/%i:\n", node->name (), node->order); dumped_sth = true; } fprintf (dump_file, " param %i: align: %u, misalign: %u\n", i, plats->alignment.align, plats->alignment.misalign); } } } /* The IPCP driver. */ static unsigned int ipcp_driver (void) { struct cgraph_2edge_hook_list *edge_duplication_hook_holder; struct cgraph_edge_hook_list *edge_removal_hook_holder; struct ipa_topo_info topo; ipa_check_create_node_params (); ipa_check_create_edge_args (); grow_edge_clone_vectors (); edge_duplication_hook_holder = symtab->add_edge_duplication_hook (&ipcp_edge_duplication_hook, NULL); edge_removal_hook_holder = symtab->add_edge_removal_hook (&ipcp_edge_removal_hook, NULL); ipcp_cst_values_pool = create_alloc_pool ("IPA-CP constant values", sizeof (ipcp_value), 32); ipcp_poly_ctx_values_pool = create_alloc_pool ("IPA-CP polymorphic contexts", sizeof (ipcp_value), 32); ipcp_sources_pool = create_alloc_pool ("IPA-CP value sources", sizeof (ipcp_value_source), 64); ipcp_agg_lattice_pool = create_alloc_pool ("IPA_CP aggregate lattices", sizeof (struct ipcp_agg_lattice), 32); if (dump_file) { fprintf (dump_file, "\nIPA structures before propagation:\n"); if (dump_flags & TDF_DETAILS) ipa_print_all_params (dump_file); ipa_print_all_jump_functions (dump_file); } /* Topological sort. */ build_toporder_info (&topo); /* Do the interprocedural propagation. */ ipcp_propagate_stage (&topo); /* Decide what constant propagation and cloning should be performed. */ ipcp_decision_stage (&topo); /* Store results of alignment propagation. */ ipcp_store_alignment_results (); /* Free all IPCP structures. */ free_toporder_info (&topo); next_edge_clone.release (); symtab->remove_edge_removal_hook (edge_removal_hook_holder); symtab->remove_edge_duplication_hook (edge_duplication_hook_holder); ipa_free_all_structures_after_ipa_cp (); if (dump_file) fprintf (dump_file, "\nIPA constant propagation end\n"); return 0; } /* Initialization and computation of IPCP data structures. This is the initial intraprocedural analysis of functions, which gathers information to be propagated later on. */ static void ipcp_generate_summary (void) { struct cgraph_node *node; if (dump_file) fprintf (dump_file, "\nIPA constant propagation start:\n"); ipa_register_cgraph_hooks (); FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) { node->local.versionable = tree_versionable_function_p (node->decl); ipa_analyze_node (node); } } /* Write ipcp summary for nodes in SET. */ static void ipcp_write_summary (void) { ipa_prop_write_jump_functions (); } /* Read ipcp summary. */ static void ipcp_read_summary (void) { ipa_prop_read_jump_functions (); } namespace { const pass_data pass_data_ipa_cp = { IPA_PASS, /* type */ "cp", /* name */ OPTGROUP_NONE, /* optinfo_flags */ TV_IPA_CONSTANT_PROP, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ ( TODO_dump_symtab | TODO_remove_functions ), /* todo_flags_finish */ }; class pass_ipa_cp : public ipa_opt_pass_d { public: pass_ipa_cp (gcc::context *ctxt) : ipa_opt_pass_d (pass_data_ipa_cp, ctxt, ipcp_generate_summary, /* generate_summary */ ipcp_write_summary, /* write_summary */ ipcp_read_summary, /* read_summary */ ipcp_write_transformation_summaries, /* write_optimization_summary */ ipcp_read_transformation_summaries, /* read_optimization_summary */ NULL, /* stmt_fixup */ 0, /* function_transform_todo_flags_start */ ipcp_transform_function, /* function_transform */ NULL) /* variable_transform */ {} /* opt_pass methods: */ virtual bool gate (function *) { /* FIXME: We should remove the optimize check after we ensure we never run IPA passes when not optimizing. */ return (flag_ipa_cp && optimize) || in_lto_p; } virtual unsigned int execute (function *) { return ipcp_driver (); } }; // class pass_ipa_cp } // anon namespace ipa_opt_pass_d * make_pass_ipa_cp (gcc::context *ctxt) { return new pass_ipa_cp (ctxt); } /* Reset all state within ipa-cp.c so that we can rerun the compiler within the same process. For use by toplev::finalize. */ void ipa_cp_c_finalize (void) { max_count = 0; overall_size = 0; max_new_size = 0; }