gcc/tree-outof-ssa.h

   1 /* Routines for expanding from SSA form to RTL.
   2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #ifndef GCC_TREE_OUTOF_SSA_H
  22 #define GCC_TREE_OUTOF_SSA_H
  23
  24
  25 /* This structure (of which only a singleton SA exists) is used to
  26    pass around information between the outof-SSA functions, cfgexpand
  27    and expand itself.  */
  28 struct ssaexpand
  29 {
  30   /* The computed partitions of SSA names are stored here.  */
  31   var_map map;
  32
  33   /* For an SSA name version V bit V is set iff TER decided that
  34      its definition should be forwarded.  */
  35   bitmap values;
  36
  37   /* For a partition number I partition_to_pseudo[I] contains the
  38      RTL expression of the allocated space of it (either a MEM or
  39      a pseudos REG).  */
  40   rtx *partition_to_pseudo;
  41
  42   /* If partition I contains an SSA name that has a default def for a
  43      parameter, bit I will be set in this bitmap.  */
  44   bitmap partitions_for_parm_default_defs;
  45
  46   /* If partition I contains an SSA name that has an undefined value,
  47      bit I will be set in this bitmap.  */
  48   bitmap partitions_for_undefined_values;
  49 };
  50
  51 /* This is the singleton described above.  */
  52 extern struct ssaexpand SA;
  53
  54 /* Returns the RTX expression representing the storage of the outof-SSA
  55    partition that the SSA name EXP is a member of.  */
  56 static inline rtx
  57 get_rtx_for_ssa_name (tree exp)
  58 {
  59   int p = partition_find (SA.map->var_partition, SSA_NAME_VERSION (exp));
  60   if (SA.map->partition_to_view)
  61     p = SA.map->partition_to_view[p];
  62   gcc_assert (p != NO_PARTITION);
  63   return SA.partition_to_pseudo[p];
  64 }
  65
  66 /* If TER decided to forward the definition of SSA name EXP this function
  67    returns the defining statement, otherwise NULL.  */
  68 static inline gimple *
  69 get_gimple_for_ssa_name (tree exp)
  70 {
  71   int v = SSA_NAME_VERSION (exp);
  72   if (SA.values && bitmap_bit_p (SA.values, v))
  73     return SSA_NAME_DEF_STMT (exp);
  74   return NULL;
  75 }
  76
  77 extern bool ssa_is_replaceable_p (gimple *stmt);
  78 extern void finish_out_of_ssa (struct ssaexpand *sa);
  79 extern unsigned int rewrite_out_of_ssa (struct ssaexpand *sa);
  80 extern void expand_phi_nodes (struct ssaexpand *sa);
  81
  82 #endif /* GCC_TREE_OUTOF_SSA_H */