1 /* IPA function body analysis. 2 Copyright (C) 2003-2018 Free Software Foundation, Inc. 3 Contributed by Jan Hubicka 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #ifndef GCC_IPA_SUMMARY_H 22 #define GCC_IPA_SUMMARY_H 23 24 #include "sreal.h" 25 #include "ipa-predicate.h" 26 27 28 /* Hints are reasons why IPA heuristics should preffer specializing given 29 function. They are represtented as bitmap of the following values. */ 30 enum ipa_hints_vals { 31 /* When specialization turns indirect call into a direct call, 32 it is good idea to do so. */ 33 INLINE_HINT_indirect_call = 1, 34 /* Inlining may make loop iterations or loop stride known. It is good idea 35 to do so because it enables loop optimizatoins. */ 36 INLINE_HINT_loop_iterations = 2, 37 INLINE_HINT_loop_stride = 4, 38 /* Inlining within same strongly connected component of callgraph is often 39 a loss due to increased stack frame usage and prologue setup costs. */ 40 INLINE_HINT_same_scc = 8, 41 /* Inlining functions in strongly connected component is not such a great 42 win. */ 43 INLINE_HINT_in_scc = 16, 44 /* If function is declared inline by user, it may be good idea to inline 45 it. Set by simple_edge_hints in ipa-inline-analysis.c. */ 46 INLINE_HINT_declared_inline = 32, 47 /* Programs are usually still organized for non-LTO compilation and thus 48 if functions are in different modules, inlining may not be so important. 49 Set by simple_edge_hints in ipa-inline-analysis.c. */ 50 INLINE_HINT_cross_module = 64, 51 /* If array indexes of loads/stores become known there may be room for 52 further optimization. */ 53 INLINE_HINT_array_index = 128, 54 /* We know that the callee is hot by profile. */ 55 INLINE_HINT_known_hot = 256 56 }; 57 58 typedef int ipa_hints; 59 60 /* Simple description of whether a memory load or a condition refers to a load 61 from an aggregate and if so, how and where from in the aggregate. 62 Individual fields have the same meaning like fields with the same name in 63 struct condition. */ 64 65 struct agg_position_info 66 { 67 HOST_WIDE_INT offset; 68 bool agg_contents; 69 bool by_ref; 70 }; 71 72 /* Representation of function body size and time depending on the call 73 context. We keep simple array of record, every containing of predicate 74 and time/size to account. */ 75 struct GTY(()) size_time_entry 76 { 77 /* Predicate for code to be executed. */ 78 predicate exec_predicate; 79 /* Predicate for value to be constant and optimized out in a specialized copy. 80 When deciding on specialization this makes it possible to see how much 81 the executed code paths will simplify. */ 82 predicate nonconst_predicate; 83 int size; 84 sreal GTY((skip)) time; 85 }; 86 87 /* Function inlining information. */ 88 struct GTY(()) ipa_fn_summary 89 { 90 /* Information about the function body itself. */ 91 92 /* Estimated stack frame consumption by the function. */ 93 HOST_WIDE_INT estimated_self_stack_size; 94 /* Size of the function body. */ 95 int self_size; 96 /* Minimal size increase after inlining. */ 97 int min_size; 98 99 /* False when there something makes inlining impossible (such as va_arg). */ 100 unsigned inlinable : 1; 101 /* True wen there is only one caller of the function before small function 102 inlining. */ 103 unsigned int single_caller : 1; 104 /* True if function contains any floating point expressions. */ 105 unsigned int fp_expressions : 1; 106 107 /* Information about function that will result after applying all the 108 inline decisions present in the callgraph. Generally kept up to 109 date only for functions that are not inline clones. */ 110 111 /* Estimated stack frame consumption by the function. */ 112 HOST_WIDE_INT estimated_stack_size; 113 /* Expected offset of the stack frame of function. */ 114 HOST_WIDE_INT stack_frame_offset; 115 /* Estimated size of the function after inlining. */ 116 sreal GTY((skip)) time; 117 int size; 118 119 /* Conditional size/time information. The summaries are being 120 merged during inlining. */ 121 conditions conds; 122 vec<size_time_entry, va_gc> *size_time_table; 123 124 /* Predicate on when some loop in the function becomes to have known 125 bounds. */ 126 predicate * GTY((skip)) loop_iterations; 127 /* Predicate on when some loop in the function becomes to have known 128 stride. */ 129 predicate * GTY((skip)) loop_stride; 130 /* Predicate on when some array indexes become constants. */ 131 predicate * GTY((skip)) array_index; 132 /* Estimated growth for inlining all copies of the function before start 133 of small functions inlining. 134 This value will get out of date as the callers are duplicated, but 135 using up-to-date value in the badness metric mean a lot of extra 136 expenses. */ 137 int growth; 138 /* Number of SCC on the beginning of inlining process. */ 139 int scc_no; 140 141 /* Keep all field empty so summary dumping works during its computation. 142 This is useful for debugging. */ 143 ipa_fn_summary () 144 : estimated_self_stack_size (0), self_size (0), min_size (0), 145 inlinable (false), single_caller (false), 146 fp_expressions (false), estimated_stack_size (false), 147 stack_frame_offset (false), time (0), size (0), conds (NULL), 148 size_time_table (NULL), loop_iterations (NULL), loop_stride (NULL), 149 array_index (NULL), growth (0), scc_no (0) 150 { 151 } 152 153 /* Record time and size under given predicates. */ 154 void account_size_time (int, sreal, const predicate &, const predicate &); 155 156 /* Reset summary to empty state. */ 157 void reset (struct cgraph_node *node); 158 159 /* We keep values scaled up, so fractional sizes can be accounted. */ 160 static const int size_scale = 2; 161 }; 162 163 class GTY((user)) ipa_fn_summary_t: public function_summary <ipa_fn_summary *> 164 { 165 public: 166 ipa_fn_summary_t (symbol_table *symtab, bool ggc): 167 function_summary <ipa_fn_summary *> (symtab, ggc) {} 168 169 static ipa_fn_summary_t *create_ggc (symbol_table *symtab) 170 { 171 struct ipa_fn_summary_t *summary = new (ggc_alloc <ipa_fn_summary_t> ()) 172 ipa_fn_summary_t(symtab, true); 173 summary->disable_insertion_hook (); 174 return summary; 175 } 176 177 178 virtual void insert (cgraph_node *, ipa_fn_summary *); 179 virtual void remove (cgraph_node *node, ipa_fn_summary *); 180 virtual void duplicate (cgraph_node *src, cgraph_node *dst, 181 ipa_fn_summary *src_data, ipa_fn_summary *dst_data); 182 }; 183 184 extern GTY(()) function_summary <ipa_fn_summary *> *ipa_fn_summaries; 185 186 /* Information kept about callgraph edges. */ 187 struct ipa_call_summary 188 { 189 class predicate *predicate; 190 /* Vector indexed by parameters. */ 191 vec<inline_param_summary> param; 192 /* Estimated size and time of the call statement. */ 193 int call_stmt_size; 194 int call_stmt_time; 195 /* Depth of loop nest, 0 means no nesting. */ 196 unsigned int loop_depth; 197 /* Indicates whether the caller returns the value of it's callee. */ 198 bool is_return_callee_uncaptured; 199 200 /* Keep all field empty so summary dumping works during its computation. 201 This is useful for debugging. */ 202 ipa_call_summary () 203 : predicate (NULL), param (vNULL), call_stmt_size (0), call_stmt_time (0), 204 loop_depth (0) 205 { 206 } 207 208 /* Reset inline summary to empty state. */ 209 void reset (); 210 }; 211 212 class ipa_call_summary_t: public call_summary <ipa_call_summary *> 213 { 214 public: 215 ipa_call_summary_t (symbol_table *symtab, bool ggc): 216 call_summary <ipa_call_summary *> (symtab, ggc) {} 217 218 /* Hook that is called by summary when an edge is duplicated. */ 219 virtual void remove (cgraph_edge *cs, ipa_call_summary *); 220 /* Hook that is called by summary when an edge is duplicated. */ 221 virtual void duplicate (cgraph_edge *src, cgraph_edge *dst, 222 ipa_call_summary *src_data, 223 ipa_call_summary *dst_data); 224 }; 225 226 extern call_summary <ipa_call_summary *> *ipa_call_summaries; 227 228 /* In ipa-fnsummary.c */ 229 void ipa_debug_fn_summary (struct cgraph_node *); 230 void ipa_dump_fn_summaries (FILE *f); 231 void ipa_dump_fn_summary (FILE *f, struct cgraph_node *node); 232 void ipa_dump_hints (FILE *f, ipa_hints); 233 void ipa_free_fn_summary (void); 234 void inline_analyze_function (struct cgraph_node *node); 235 void estimate_ipcp_clone_size_and_time (struct cgraph_node *, 236 vec<tree>, 237 vec<ipa_polymorphic_call_context>, 238 vec<ipa_agg_jump_function_p>, 239 int *, sreal *, sreal *, 240 ipa_hints *); 241 void ipa_merge_fn_summary_after_inlining (struct cgraph_edge *edge); 242 void ipa_update_overall_fn_summary (struct cgraph_node *node); 243 void compute_fn_summary (struct cgraph_node *, bool); 244 245 246 void evaluate_properties_for_edge (struct cgraph_edge *e, bool inline_p, 247 clause_t *clause_ptr, 248 clause_t *nonspec_clause_ptr, 249 vec<tree> *known_vals_ptr, 250 vec<ipa_polymorphic_call_context> 251 *known_contexts_ptr, 252 vec<ipa_agg_jump_function_p> *); 253 void estimate_node_size_and_time (struct cgraph_node *node, 254 clause_t possible_truths, 255 clause_t nonspec_possible_truths, 256 vec<tree> known_vals, 257 vec<ipa_polymorphic_call_context>, 258 vec<ipa_agg_jump_function_p> known_aggs, 259 int *ret_size, int *ret_min_size, 260 sreal *ret_time, 261 sreal *ret_nonspecialized_time, 262 ipa_hints *ret_hints, 263 vec<inline_param_summary> 264 inline_param_summary); 265 266 void ipa_fnsummary_c_finalize (void); 267 268 #endif /* GCC_IPA_FNSUMMARY_H */ 269