gcc/cfg-flags.def

   1 /* Flags on basic blocks and edges.
   2    Copyright (C) 2012-2023 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 it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 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 /* This file defines flags that may appear on basic blocks or on
  21    edges.  Source files define DEF_BASIC_BLOCK_FLAG or DEF_EDGE_FLAG
  22    appropriately before including this file.  */
  23
  24 #if !defined(DEF_BASIC_BLOCK_FLAG) && !defined(DEF_EDGE_FLAG)
  25 #error "You must define DEF_BASIC_BLOCK_FLAG or DEF_EDGE_FLAG"
  26 #endif
  27
  28 #ifdef DEF_BASIC_BLOCK_FLAG
  29
  30 /* Masks for basic_block.flags.
  31
  32    The format of this file is: DEF_BASIC_BLOCK_FLAG(NAME, IDX).
  33    NAME is the name of the basic block flag.  A flag BB_#NAME will be
  34    created and the name is used in dump_edge_info.
  35    IDX is a sequence number that is used to determine the value
  36    of the flag, which is 1 << IDX).
  37
  38    BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
  39    the compilation, so they are never cleared.
  40
  41    All other flags may be cleared by clear_bb_flags().  It is generally
  42    a bad idea to rely on any flags being up-to-date.  */
  43
  44 /* Only set on blocks that have just been created by create_bb.  */
  45 DEF_BASIC_BLOCK_FLAG(NEW, 0)
  46
  47 /* Set by find_unreachable_blocks.  Do not rely on this being set in any
  48    pass.  */
  49 DEF_BASIC_BLOCK_FLAG(REACHABLE, 1)
  50
  51 /* Set for blocks in an irreducible loop by loop analysis.  */
  52 DEF_BASIC_BLOCK_FLAG(IRREDUCIBLE_LOOP, 2)
  53
  54 /* Set on blocks that may actually not be single-entry single-exit block.  */
  55 DEF_BASIC_BLOCK_FLAG(SUPERBLOCK, 3)
  56
  57 /* Set on basic blocks that the scheduler should not touch.  This is used
  58    by SMS to prevent other schedulers from messing with the loop schedule.  */
  59 DEF_BASIC_BLOCK_FLAG(DISABLE_SCHEDULE, 4)
  60
  61 /* Set on blocks that should be put in a hot section.  */
  62 DEF_BASIC_BLOCK_FLAG(HOT_PARTITION, 5)
  63
  64 /* Set on blocks that should be put in a cold section.  */
  65 DEF_BASIC_BLOCK_FLAG(COLD_PARTITION, 6)
  66
  67 /* Set on block that was duplicated.  */
  68 DEF_BASIC_BLOCK_FLAG(DUPLICATED, 7)
  69
  70 /* Set if the label at the top of this block is the target of a non-local goto.  */
  71 DEF_BASIC_BLOCK_FLAG(NON_LOCAL_GOTO_TARGET, 8)
  72
  73 /* Set on blocks that are in RTL format.  */
  74 DEF_BASIC_BLOCK_FLAG(RTL, 9)
  75
  76 /* Set on blocks that are forwarder blocks.
  77    Only used in cfgcleanup.cc.  */
  78 DEF_BASIC_BLOCK_FLAG(FORWARDER_BLOCK, 10)
  79
  80 /* Set on blocks that cannot be threaded through.
  81    Only used for jump threading.  */
  82 DEF_BASIC_BLOCK_FLAG(NONTHREADABLE_BLOCK, 11)
  83
  84 /* Set on blocks that were modified in some way.  This bit is set in
  85    df_set_bb_dirty, but not cleared by df_analyze, so it can be used
  86    to test whether a block has been modified prior to a df_analyze call.  */
  87 DEF_BASIC_BLOCK_FLAG(MODIFIED, 12)
  88
  89 /* A general visited flag for passes to use.  */
  90 DEF_BASIC_BLOCK_FLAG(VISITED, 13)
  91
  92 /* Set on blocks that are in a transaction.  This is calculated on
  93    demand, and is available after calling compute_transaction_bits().  */
  94 DEF_BASIC_BLOCK_FLAG(IN_TRANSACTION, 14)
  95
  96 #endif
  97
  98 #ifdef DEF_EDGE_FLAG
  99
 100 /* Masks for edge.flags.
 101
 102    The format of this file is: DEF_EDGE_FLAG(NAME, IDX, STRING).
 103    NAME is the name of the edge flag.  A flag EDGE_#NAME will be
 104    created and the name is used in dump_edge_info.
 105    IDX is a sequence number that is used to determine the value
 106    of the flag, which is 1 << IDX).  */
 107
 108 /* 'Straight line' flow.  In GIMPLE and in cfglayout mode, all normal
 109    edges are fallthru edges.  In cfgrtl mode, this flag really means
 110    that control flow falls through to the next basic block in the line.  */
 111 DEF_EDGE_FLAG(FALLTHRU, 0)
 112
 113 /* Strange flow, like a computed jump or exception handling.  Usually
 114    this means that the edge cannot be split.  */
 115 DEF_EDGE_FLAG(ABNORMAL, 1)
 116
 117 /* Edge out of a basic block that ends with a CALL_INSN with abnormal
 118    exit, like an exception or a non-local goto.
 119    ABNORMAL_CALL edges also have ABNORMAL set.
 120    This flag is only used for the RTL CFG.  */
 121 DEF_EDGE_FLAG(ABNORMAL_CALL, 2)
 122
 123 /* Exception edge.  Exception handling edges represent possible control
 124    transfers from a trapping instruction to an exception handler.
 125    EH edges also have ABNORMAL set for the RTL CFG.  */
 126 DEF_EDGE_FLAG(EH, 3)
 127
 128 /* Never merge blocks via this edge.  This is used for exception handling,
 129    to prevent merging away edges to the post-landing-pad basic block.
 130    This flag is only used for the RTL CFG.  */
 131 DEF_EDGE_FLAG(PRESERVE, 4)
 132
 133 /* Not a real edge.  This is used to connect parts of the CFG that do
 134    not halt, such as infinite loops and noreturn functions, to the
 135    EXIT_BLOCK, so that traversing of the reverse CFG is possible.  */
 136 DEF_EDGE_FLAG(FAKE, 5)
 137
 138 /* A back edge, marked in a depth-first search of the CFG.  Back edges
 139    are hints that this edge may be part of a loop in the CFG.  */
 140 DEF_EDGE_FLAG(DFS_BACK, 6)
 141
 142 /* Edge in a part of the CFG that is an irreducible loop.  */
 143 DEF_EDGE_FLAG(IRREDUCIBLE_LOOP, 7)
 144
 145 /* Edge taken when controlling predicate is nonzero.
 146    This is only used for the GIMPLE CFG.  */
 147 DEF_EDGE_FLAG(TRUE_VALUE, 8)
 148
 149 /* Edge taken when controlling predicate is zero.
 150    This is only used for the GIMPLE CFG.  */
 151 DEF_EDGE_FLAG(FALSE_VALUE, 9)
 152
 153 /* Edge is executable.  This is only used in GIMPLE SSA-CCP and VRP.
 154    This is only used for the GIMPLE CFG.  */
 155 DEF_EDGE_FLAG(EXECUTABLE, 10)
 156
 157 /* Edge crosses between hot and cold sections, when we do partitioning.
 158    This flag is only used for the RTL CFG.  */
 159 DEF_EDGE_FLAG(CROSSING, 11)
 160
 161 /* Edge from a sibcall CALL_INSN to exit.
 162    SIBCALL edges also have ABNORMAL set.
 163    This flag is only used for the RTL CFG.  */
 164 DEF_EDGE_FLAG(SIBCALL, 12)
 165
 166 /* Candidate for straight line flow.  Only used in bb-reorder.cc.
 167    This flag is only used for the RTL CFG.  */
 168 DEF_EDGE_FLAG(CAN_FALLTHRU, 13)
 169
 170 /* Exit of a loop.  This is only used in ifcvt.cc.
 171    This flag is only used for the RTL CFG.  */
 172 DEF_EDGE_FLAG(LOOP_EXIT, 14)
 173
 174 /* Uninstrumented edge out of a GIMPLE_TRANSACTION statement.  */
 175 DEF_EDGE_FLAG(TM_UNINSTRUMENTED, 15)
 176
 177 /* Abort (over) edge out of a GIMPLE_TRANSACTION statement.  */
 178 DEF_EDGE_FLAG(TM_ABORT, 16)
 179
 180 /* An edge we should ignore.  It should be entirely local to
 181    passes.  ie, it is never set on any edge upon the completion
 182    of any pass.  */
 183 DEF_EDGE_FLAG(IGNORE, 17)
 184
 185 #endif
 186
 187 /*
 188 Local variables:
 189 mode:c
 190 End:
 191 */