gcc/integrate.c

   1 /* Procedure integration for GCC.
   2    Copyright (C) 1988, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   3    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   4    Contributed by Michael Tiemann (tiemann@cygnus.com)
   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 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26
  27 #include "rtl.h"
  28 #include "tree.h"
  29 #include "tm_p.h"
  30 #include "regs.h"
  31 #include "flags.h"
  32 #include "debug.h"
  33 #include "insn-config.h"
  34 #include "expr.h"
  35 #include "output.h"
  36 #include "recog.h"
  37 #include "integrate.h"
  38 #include "real.h"
  39 #include "except.h"
  40 #include "function.h"
  41 #include "toplev.h"
  42 #include "intl.h"
  43 #include "params.h"
  44 #include "ggc.h"
  45 #include "target.h"
  46 #include "langhooks.h"
  47 #include "tree-pass.h"
  48 #include "df.h"
  49
  50 /* Round to the next highest integer that meets the alignment.  */
  51 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
  52 \f
  53
  54 /* Private type used by {get/has}_hard_reg_initial_val.  */
  55 typedef struct initial_value_pair GTY(()) {
  56   rtx hard_reg;
  57   rtx pseudo;
  58 } initial_value_pair;
  59 typedef struct initial_value_struct GTY(()) {
  60   int num_entries;
  61   int max_entries;
  62   initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
  63 } initial_value_struct;
  64
  65 static void set_block_origin_self (tree);
  66 static void set_block_abstract_flags (tree, int);
  67 \f
  68
  69 /* Return false if the function FNDECL cannot be inlined on account of its
  70    attributes, true otherwise.  */
  71 bool
  72 function_attribute_inlinable_p (tree fndecl)
  73 {
  74   if (targetm.attribute_table)
  75     {
  76       tree a;
  77
  78       for (a = DECL_ATTRIBUTES (fndecl); a; a = TREE_CHAIN (a))
  79         {
  80           tree name = TREE_PURPOSE (a);
  81           int i;
  82
  83           for (i = 0; targetm.attribute_table[i].name != NULL; i++)
  84             if (is_attribute_p (targetm.attribute_table[i].name, name))
  85               return targetm.function_attribute_inlinable_p (fndecl);
  86         }
  87     }
  88
  89   return true;
  90 }
  91 \f
  92 /* Given a pointer to some BLOCK node, if the BLOCK_ABSTRACT_ORIGIN for the
  93    given BLOCK node is NULL, set the BLOCK_ABSTRACT_ORIGIN for the node so
  94    that it points to the node itself, thus indicating that the node is its
  95    own (abstract) origin.  Additionally, if the BLOCK_ABSTRACT_ORIGIN for
  96    the given node is NULL, recursively descend the decl/block tree which
  97    it is the root of, and for each other ..._DECL or BLOCK node contained
  98    therein whose DECL_ABSTRACT_ORIGINs or BLOCK_ABSTRACT_ORIGINs are also
  99    still NULL, set *their* DECL_ABSTRACT_ORIGIN or BLOCK_ABSTRACT_ORIGIN
 100    values to point to themselves.  */
 101
 102 static void
 103 set_block_origin_self (tree stmt)
 104 {
 105   if (BLOCK_ABSTRACT_ORIGIN (stmt) == NULL_TREE)
 106     {
 107       BLOCK_ABSTRACT_ORIGIN (stmt) = stmt;
 108
 109       {
 110         tree local_decl;
 111
 112         for (local_decl = BLOCK_VARS (stmt);
 113              local_decl != NULL_TREE;
 114              local_decl = TREE_CHAIN (local_decl))
 115           set_decl_origin_self (local_decl);    /* Potential recursion.  */
 116       }
 117
 118       {
 119         tree subblock;
 120
 121         for (subblock = BLOCK_SUBBLOCKS (stmt);
 122              subblock != NULL_TREE;
 123              subblock = BLOCK_CHAIN (subblock))
 124           set_block_origin_self (subblock);     /* Recurse.  */
 125       }
 126     }
 127 }
 128
 129 /* Given a pointer to some ..._DECL node, if the DECL_ABSTRACT_ORIGIN for
 130    the given ..._DECL node is NULL, set the DECL_ABSTRACT_ORIGIN for the
 131    node to so that it points to the node itself, thus indicating that the
 132    node represents its own (abstract) origin.  Additionally, if the
 133    DECL_ABSTRACT_ORIGIN for the given node is NULL, recursively descend
 134    the decl/block tree of which the given node is the root of, and for
 135    each other ..._DECL or BLOCK node contained therein whose
 136    DECL_ABSTRACT_ORIGINs or BLOCK_ABSTRACT_ORIGINs are also still NULL,
 137    set *their* DECL_ABSTRACT_ORIGIN or BLOCK_ABSTRACT_ORIGIN values to
 138    point to themselves.  */
 139
 140 void
 141 set_decl_origin_self (tree decl)
 142 {
 143   if (DECL_ABSTRACT_ORIGIN (decl) == NULL_TREE)
 144     {
 145       DECL_ABSTRACT_ORIGIN (decl) = decl;
 146       if (TREE_CODE (decl) == FUNCTION_DECL)
 147         {
 148           tree arg;
 149
 150           for (arg = DECL_ARGUMENTS (decl); arg; arg = TREE_CHAIN (arg))
 151             DECL_ABSTRACT_ORIGIN (arg) = arg;
 152           if (DECL_INITIAL (decl) != NULL_TREE
 153               && DECL_INITIAL (decl) != error_mark_node)
 154             set_block_origin_self (DECL_INITIAL (decl));
 155         }
 156     }
 157 }
 158 \f
 159 /* Given a pointer to some BLOCK node, and a boolean value to set the
 160    "abstract" flags to, set that value into the BLOCK_ABSTRACT flag for
 161    the given block, and for all local decls and all local sub-blocks
 162    (recursively) which are contained therein.  */
 163
 164 static void
 165 set_block_abstract_flags (tree stmt, int setting)
 166 {
 167   tree local_decl;
 168   tree subblock;
 169
 170   BLOCK_ABSTRACT (stmt) = setting;
 171
 172   for (local_decl = BLOCK_VARS (stmt);
 173        local_decl != NULL_TREE;
 174        local_decl = TREE_CHAIN (local_decl))
 175     set_decl_abstract_flags (local_decl, setting);
 176
 177   for (subblock = BLOCK_SUBBLOCKS (stmt);
 178        subblock != NULL_TREE;
 179        subblock = BLOCK_CHAIN (subblock))
 180     set_block_abstract_flags (subblock, setting);
 181 }
 182
 183 /* Given a pointer to some ..._DECL node, and a boolean value to set the
 184    "abstract" flags to, set that value into the DECL_ABSTRACT flag for the
 185    given decl, and (in the case where the decl is a FUNCTION_DECL) also
 186    set the abstract flags for all of the parameters, local vars, local
 187    blocks and sub-blocks (recursively) to the same setting.  */
 188
 189 void
 190 set_decl_abstract_flags (tree decl, int setting)
 191 {
 192   DECL_ABSTRACT (decl) = setting;
 193   if (TREE_CODE (decl) == FUNCTION_DECL)
 194     {
 195       tree arg;
 196
 197       for (arg = DECL_ARGUMENTS (decl); arg; arg = TREE_CHAIN (arg))
 198         DECL_ABSTRACT (arg) = setting;
 199       if (DECL_INITIAL (decl) != NULL_TREE
 200           && DECL_INITIAL (decl) != error_mark_node)
 201         set_block_abstract_flags (DECL_INITIAL (decl), setting);
 202     }
 203 }
 204 \f
 205 /* Functions to keep track of the values hard regs had at the start of
 206    the function.  */
 207
 208 rtx
 209 get_hard_reg_initial_reg (struct function *fun, rtx reg)
 210 {
 211   struct initial_value_struct *ivs = fun->hard_reg_initial_vals;
 212   int i;
 213
 214   if (ivs == 0)
 215     return NULL_RTX;
 216
 217   for (i = 0; i < ivs->num_entries; i++)
 218     if (rtx_equal_p (ivs->entries[i].pseudo, reg))
 219       return ivs->entries[i].hard_reg;
 220
 221   return NULL_RTX;
 222 }
 223
 224 /* Make sure that there's a pseudo register of mode MODE that stores the
 225    initial value of hard register REGNO.  Return an rtx for such a pseudo.  */
 226
 227 rtx
 228 get_hard_reg_initial_val (enum machine_mode mode, unsigned int regno)
 229 {
 230   struct initial_value_struct *ivs;
 231   rtx rv;
 232
 233   rv = has_hard_reg_initial_val (mode, regno);
 234   if (rv)
 235     return rv;
 236
 237   ivs = cfun->hard_reg_initial_vals;
 238   if (ivs == 0)
 239     {
 240       ivs = ggc_alloc (sizeof (initial_value_struct));
 241       ivs->num_entries = 0;
 242       ivs->max_entries = 5;
 243       ivs->entries = ggc_alloc (5 * sizeof (initial_value_pair));
 244       cfun->hard_reg_initial_vals = ivs;
 245     }
 246
 247   if (ivs->num_entries >= ivs->max_entries)
 248     {
 249       ivs->max_entries += 5;
 250       ivs->entries = ggc_realloc (ivs->entries,
 251                                   ivs->max_entries
 252                                   * sizeof (initial_value_pair));
 253     }
 254
 255   ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
 256   ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
 257
 258   return ivs->entries[ivs->num_entries++].pseudo;
 259 }
 260
 261 /* See if get_hard_reg_initial_val has been used to create a pseudo
 262    for the initial value of hard register REGNO in mode MODE.  Return
 263    the associated pseudo if so, otherwise return NULL.  */
 264
 265 rtx
 266 has_hard_reg_initial_val (enum machine_mode mode, unsigned int regno)
 267 {
 268   struct initial_value_struct *ivs;
 269   int i;
 270
 271   ivs = cfun->hard_reg_initial_vals;
 272   if (ivs != 0)
 273     for (i = 0; i < ivs->num_entries; i++)
 274       if (GET_MODE (ivs->entries[i].hard_reg) == mode
 275           && REGNO (ivs->entries[i].hard_reg) == regno)
 276         return ivs->entries[i].pseudo;
 277
 278   return NULL_RTX;
 279 }
 280
 281 unsigned int
 282 emit_initial_value_sets (void)
 283 {
 284   struct initial_value_struct *ivs = cfun->hard_reg_initial_vals;
 285   int i;
 286   rtx seq;
 287
 288   if (ivs == 0)
 289     return 0;
 290
 291   start_sequence ();
 292   for (i = 0; i < ivs->num_entries; i++)
 293     emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
 294   seq = get_insns ();
 295   end_sequence ();
 296
 297   emit_insn_at_entry (seq);
 298   return 0;
 299 }
 300
 301 struct tree_opt_pass pass_initial_value_sets =
 302 {
 303   "initvals",                           /* name */
 304   NULL,                                 /* gate */
 305   emit_initial_value_sets,              /* execute */
 306   NULL,                                 /* sub */
 307   NULL,                                 /* next */
 308   0,                                    /* static_pass_number */
 309   0,                                    /* tv_id */
 310   0,                                    /* properties_required */
 311   0,                                    /* properties_provided */
 312   0,                                    /* properties_destroyed */
 313   0,                                    /* todo_flags_start */
 314   TODO_dump_func,                       /* todo_flags_finish */
 315   0                                     /* letter */
 316 };
 317
 318 /* If the backend knows where to allocate pseudos for hard
 319    register initial values, register these allocations now.  */
 320 void
 321 allocate_initial_values (rtx *reg_equiv_memory_loc)
 322 {
 323   if (targetm.allocate_initial_value)
 324     {
 325       struct initial_value_struct *ivs = cfun->hard_reg_initial_vals;
 326       int i;
 327
 328       if (ivs == 0)
 329         return;
 330
 331       for (i = 0; i < ivs->num_entries; i++)
 332         {
 333           int regno = REGNO (ivs->entries[i].pseudo);
 334           rtx x = targetm.allocate_initial_value (ivs->entries[i].hard_reg);
 335
 336           if (x && REG_N_SETS (REGNO (ivs->entries[i].pseudo)) <= 1)
 337             {
 338               if (MEM_P (x))
 339                 reg_equiv_memory_loc[regno] = x;
 340               else
 341                 {
 342                   basic_block bb;
 343                   int new_regno;
 344
 345                   gcc_assert (REG_P (x));
 346                   new_regno = REGNO (x);
 347                   reg_renumber[regno] = new_regno;
 348                   /* Poke the regno right into regno_reg_rtx so that even
 349                      fixed regs are accepted.  */
 350                   SET_REGNO (ivs->entries[i].pseudo, new_regno);
 351                   /* Update global register liveness information.  */
 352                   FOR_EACH_BB (bb)
 353                     {
 354                       if (REGNO_REG_SET_P(df_get_live_in (bb), regno))
 355                         SET_REGNO_REG_SET (df_get_live_in (bb), new_regno);
 356                       if (REGNO_REG_SET_P(df_get_live_out (bb), regno))
 357                         SET_REGNO_REG_SET (df_get_live_out (bb), new_regno);
 358                     }
 359                 }
 360             }
 361         }
 362     }
 363 }
 364
 365 #include "gt-integrate.h"