gcc/ipa-inline.h

   1 /* Inlining decision heuristics.
   2    Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4    Contributed by Jan Hubicka
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 /* Representation of inline parameters that do depend on context function is
  23    inlined into (i.e. known constant values of function parameters.
  24
  25    Conditions that are interesting for function body are collected into CONDS
  26    vector.  They are of simple for  function_param OP VAL, where VAL is
  27    IPA invariant.  The conditions are then refered by predicates.  */
  28
  29 typedef struct GTY(()) condition
  30   {
  31     tree val;
  32     int operand_num;
  33     enum tree_code code;
  34   } condition;
  35
  36 DEF_VEC_O (condition);
  37 DEF_VEC_ALLOC_O (condition, gc);
  38
  39 typedef VEC(condition,gc) *conditions;
  40
  41 /* Representation of predicates i.e. formulas using conditions defined
  42    above.  Predicates are simple logical formulas in conjunctive-disjunctive
  43    form.
  44
  45    Predicate is array of clauses terminated by 0.  Every clause must be true
  46    in order to make predicate true.
  47    Clauses are represented as bitmaps of conditions. One of conditions
  48    must be true in order for clause to be true.  */
  49
  50 #define MAX_CLAUSES 8
  51 typedef int clause_t;
  52 struct GTY(()) predicate
  53 {
  54   clause_t clause[MAX_CLAUSES + 1];
  55 };
  56
  57 /* Represnetation of function body size and time depending on the inline
  58    context.  We keep simple array of record, every containing of predicate
  59    and time/size to account.
  60
  61    We keep values scaled up, so fractional sizes and times can be
  62    accounted.  */
  63 #define INLINE_SIZE_SCALE 2
  64 #define INLINE_TIME_SCALE (CGRAPH_FREQ_BASE * 2)
  65 typedef struct GTY(()) size_time_entry
  66 {
  67   struct predicate predicate;
  68   int size;
  69   int time;
  70 } size_time_entry;
  71 DEF_VEC_O (size_time_entry);
  72 DEF_VEC_ALLOC_O (size_time_entry, gc);
  73
  74 /* Function inlining information.  */
  75 struct GTY(()) inline_summary
  76 {
  77   /* Information about the function body itself.  */
  78
  79   /* Estimated stack frame consumption by the function.  */
  80   HOST_WIDE_INT estimated_self_stack_size;
  81   /* Size of the function body.  */
  82   int self_size;
  83   /* Time of the function body.  */
  84   int self_time;
  85
  86   /* False when there something makes inlining impossible (such as va_arg).  */
  87   unsigned inlinable : 1;
  88   /* False when there something makes versioning impossible.
  89      Currently computed and used only by ipa-cp.  */
  90   unsigned versionable : 1;
  91
  92   /* Information about function that will result after applying all the
  93      inline decisions present in the callgraph.  Generally kept up to
  94      date only for functions that are not inline clones. */
  95
  96   /* Estimated stack frame consumption by the function.  */
  97   HOST_WIDE_INT estimated_stack_size;
  98   /* Expected offset of the stack frame of inlined function.  */
  99   HOST_WIDE_INT stack_frame_offset;
 100   /* Estimated size of the function after inlining.  */
 101   int time;
 102   int size;
 103
 104   /* Conditional size/time information.  The summaries are being
 105      merged during inlining.  */
 106   conditions conds;
 107   VEC(size_time_entry,gc) *entry;
 108 };
 109
 110 typedef struct inline_summary inline_summary_t;
 111 DEF_VEC_O(inline_summary_t);
 112 DEF_VEC_ALLOC_O(inline_summary_t,gc);
 113 extern GTY(()) VEC(inline_summary_t,gc) *inline_summary_vec;
 114
 115 /* Information kept about callgraph edges.  */
 116 struct inline_edge_summary
 117 {
 118   /* Estimated size and time of the call statement.  */
 119   int call_stmt_size;
 120   int call_stmt_time;
 121   /* Depth of loop nest, 0 means no nesting.  */
 122   unsigned short int loop_depth;
 123 };
 124
 125 typedef struct inline_edge_summary inline_edge_summary_t;
 126 DEF_VEC_O(inline_edge_summary_t);
 127 DEF_VEC_ALLOC_O(inline_edge_summary_t,heap);
 128 extern VEC(inline_edge_summary_t,heap) *inline_edge_summary_vec;
 129
 130 typedef struct edge_growth_cache_entry
 131 {
 132   int time, size;
 133 } edge_growth_cache_entry;
 134 DEF_VEC_O(edge_growth_cache_entry);
 135 DEF_VEC_ALLOC_O(edge_growth_cache_entry,heap);
 136
 137 extern VEC(int,heap) *node_growth_cache;
 138 extern VEC(edge_growth_cache_entry,heap) *edge_growth_cache;
 139
 140 /* In ipa-inline-analysis.c  */
 141 void debug_inline_summary (struct cgraph_node *);
 142 void dump_inline_summaries (FILE *f);
 143 void inline_generate_summary (void);
 144 void inline_read_summary (void);
 145 void inline_write_summary (cgraph_node_set, varpool_node_set);
 146 void inline_free_summary (void);
 147 void initialize_inline_failed (struct cgraph_edge *);
 148 int estimate_time_after_inlining (struct cgraph_node *, struct cgraph_edge *);
 149 int estimate_size_after_inlining (struct cgraph_node *, struct cgraph_edge *);
 150 int do_estimate_growth (struct cgraph_node *);
 151 void inline_merge_summary (struct cgraph_edge *edge);
 152 int do_estimate_edge_growth (struct cgraph_edge *edge);
 153 int do_estimate_edge_time (struct cgraph_edge *edge);
 154 void initialize_growth_caches (void);
 155 void free_growth_caches (void);
 156 void compute_inline_parameters (struct cgraph_node *, bool);
 157
 158 /* In ipa-inline-transform.c  */
 159 bool inline_call (struct cgraph_edge *, bool, VEC (cgraph_edge_p, heap) **, int *);
 160 unsigned int inline_transform (struct cgraph_node *);
 161 void clone_inlined_nodes (struct cgraph_edge *e, bool, bool, int *);
 162
 163 extern int ncalls_inlined;
 164 extern int nfunctions_inlined;
 165
 166 static inline struct inline_summary *
 167 inline_summary (struct cgraph_node *node)
 168 {
 169   return VEC_index (inline_summary_t, inline_summary_vec, node->uid);
 170 }
 171
 172 static inline struct inline_edge_summary *
 173 inline_edge_summary (struct cgraph_edge *edge)
 174 {
 175   return VEC_index (inline_edge_summary_t,
 176                     inline_edge_summary_vec, edge->uid);
 177 }
 178
 179 /* Return estimated unit growth after inlning all calls to NODE.
 180    Quick accesors to the inline growth caches.
 181    For convenience we keep zero 0 as unknown.  Because growth
 182    can be both positive and negative, we simply increase positive
 183    growths by 1. */
 184 static inline int
 185 estimate_growth (struct cgraph_node *node)
 186 {
 187   int ret;
 188   if ((int)VEC_length (int, node_growth_cache) <= node->uid
 189       || !(ret = VEC_index (int, node_growth_cache, node->uid)))
 190     return do_estimate_growth (node);
 191   return ret - (ret > 0);
 192 }
 193
 194
 195 /* Return estimated callee growth after inlining EDGE.  */
 196
 197 static inline int
 198 estimate_edge_growth (struct cgraph_edge *edge)
 199 {
 200   int ret;
 201   if ((int)VEC_length (edge_growth_cache_entry, edge_growth_cache) <= edge->uid
 202       || !(ret = VEC_index (edge_growth_cache_entry,
 203                             edge_growth_cache,
 204                             edge->uid)->size))
 205     return do_estimate_edge_growth (edge);
 206   return ret - (ret > 0);
 207 }
 208
 209
 210 /* Return estimated callee runtime increase after inlning
 211    EDGE.  */
 212
 213 static inline int
 214 estimate_edge_time (struct cgraph_edge *edge)
 215 {
 216   int ret;
 217   if ((int)VEC_length (edge_growth_cache_entry, edge_growth_cache) <= edge->uid
 218       || !(ret = VEC_index (edge_growth_cache_entry,
 219                             edge_growth_cache,
 220                             edge->uid)->size))
 221     return do_estimate_edge_time (edge);
 222   return ret - (ret > 0);
 223 }
 224
 225
 226 /* Reset cached value for NODE.  */
 227
 228 static inline void
 229 reset_node_growth_cache (struct cgraph_node *node)
 230 {
 231   if ((int)VEC_length (int, node_growth_cache) > node->uid)
 232     VEC_replace (int, node_growth_cache, node->uid, 0);
 233 }
 234
 235 /* Reset cached value for EDGE.  */
 236
 237 static inline void
 238 reset_edge_growth_cache (struct cgraph_edge *edge)
 239 {
 240   if ((int)VEC_length (edge_growth_cache_entry, edge_growth_cache) > edge->uid)
 241     {
 242       struct edge_growth_cache_entry zero = {0, 0};
 243       VEC_replace (edge_growth_cache_entry, edge_growth_cache, edge->uid, &zero);
 244     }
 245 }