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   struct predicate *predicate;
 124 };
 125
 126 typedef struct inline_edge_summary inline_edge_summary_t;
 127 DEF_VEC_O(inline_edge_summary_t);
 128 DEF_VEC_ALLOC_O(inline_edge_summary_t,heap);
 129 extern VEC(inline_edge_summary_t,heap) *inline_edge_summary_vec;
 130
 131 typedef struct edge_growth_cache_entry
 132 {
 133   int time, size;
 134 } edge_growth_cache_entry;
 135 DEF_VEC_O(edge_growth_cache_entry);
 136 DEF_VEC_ALLOC_O(edge_growth_cache_entry,heap);
 137
 138 extern VEC(int,heap) *node_growth_cache;
 139 extern VEC(edge_growth_cache_entry,heap) *edge_growth_cache;
 140
 141 /* In ipa-inline-analysis.c  */
 142 void debug_inline_summary (struct cgraph_node *);
 143 void dump_inline_summaries (FILE *f);
 144 void inline_generate_summary (void);
 145 void inline_read_summary (void);
 146 void inline_write_summary (cgraph_node_set, varpool_node_set);
 147 void inline_free_summary (void);
 148 void initialize_inline_failed (struct cgraph_edge *);
 149 int estimate_time_after_inlining (struct cgraph_node *, struct cgraph_edge *);
 150 int estimate_size_after_inlining (struct cgraph_node *, struct cgraph_edge *);
 151 int do_estimate_growth (struct cgraph_node *);
 152 void inline_merge_summary (struct cgraph_edge *edge);
 153 int do_estimate_edge_growth (struct cgraph_edge *edge);
 154 int do_estimate_edge_time (struct cgraph_edge *edge);
 155 void initialize_growth_caches (void);
 156 void free_growth_caches (void);
 157 void compute_inline_parameters (struct cgraph_node *, bool);
 158
 159 /* In ipa-inline-transform.c  */
 160 bool inline_call (struct cgraph_edge *, bool, VEC (cgraph_edge_p, heap) **, int *);
 161 unsigned int inline_transform (struct cgraph_node *);
 162 void clone_inlined_nodes (struct cgraph_edge *e, bool, bool, int *);
 163
 164 extern int ncalls_inlined;
 165 extern int nfunctions_inlined;
 166
 167 static inline struct inline_summary *
 168 inline_summary (struct cgraph_node *node)
 169 {
 170   return VEC_index (inline_summary_t, inline_summary_vec, node->uid);
 171 }
 172
 173 static inline struct inline_edge_summary *
 174 inline_edge_summary (struct cgraph_edge *edge)
 175 {
 176   return VEC_index (inline_edge_summary_t,
 177                     inline_edge_summary_vec, edge->uid);
 178 }
 179
 180 /* Return estimated unit growth after inlning all calls to NODE.
 181    Quick accesors to the inline growth caches.
 182    For convenience we keep zero 0 as unknown.  Because growth
 183    can be both positive and negative, we simply increase positive
 184    growths by 1. */
 185 static inline int
 186 estimate_growth (struct cgraph_node *node)
 187 {
 188   int ret;
 189   if ((int)VEC_length (int, node_growth_cache) <= node->uid
 190       || !(ret = VEC_index (int, node_growth_cache, node->uid)))
 191     return do_estimate_growth (node);
 192   return ret - (ret > 0);
 193 }
 194
 195
 196 /* Return estimated callee growth after inlining EDGE.  */
 197
 198 static inline int
 199 estimate_edge_growth (struct cgraph_edge *edge)
 200 {
 201   int ret;
 202   if ((int)VEC_length (edge_growth_cache_entry, edge_growth_cache) <= edge->uid
 203       || !(ret = VEC_index (edge_growth_cache_entry,
 204                             edge_growth_cache,
 205                             edge->uid)->size))
 206     return do_estimate_edge_growth (edge);
 207   return ret - (ret > 0);
 208 }
 209
 210
 211 /* Return estimated callee runtime increase after inlning
 212    EDGE.  */
 213
 214 static inline int
 215 estimate_edge_time (struct cgraph_edge *edge)
 216 {
 217   int ret;
 218   if ((int)VEC_length (edge_growth_cache_entry, edge_growth_cache) <= edge->uid
 219       || !(ret = VEC_index (edge_growth_cache_entry,
 220                             edge_growth_cache,
 221                             edge->uid)->size))
 222     return do_estimate_edge_time (edge);
 223   return ret - (ret > 0);
 224 }
 225
 226
 227 /* Reset cached value for NODE.  */
 228
 229 static inline void
 230 reset_node_growth_cache (struct cgraph_node *node)
 231 {
 232   if ((int)VEC_length (int, node_growth_cache) > node->uid)
 233     VEC_replace (int, node_growth_cache, node->uid, 0);
 234 }
 235
 236 /* Reset cached value for EDGE.  */
 237
 238 static inline void
 239 reset_edge_growth_cache (struct cgraph_edge *edge)
 240 {
 241   if ((int)VEC_length (edge_growth_cache_entry, edge_growth_cache) > edge->uid)
 242     {
 243       struct edge_growth_cache_entry zero = {0, 0};
 244       VEC_replace (edge_growth_cache_entry, edge_growth_cache, edge->uid, &zero);
 245     }
 246 }