Data Fields | |
| rtx | pattern |
| rtx | pattern_regs |
| rtx | antic_stores |
| rtx | avail_stores |
| struct st_expr * | next |
| int | index |
| unsigned int | hash_index |
| rtx | reaching_reg |
Detailed Description
@verbatim
Store motion via Lazy Code Motion on the reverse CFG. Copyright (C) 1997-2013 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see http://www.gnu.org/licenses/.
This pass implements downward store motion. As of May 1, 2009, the pass is not enabled by default on any target, but bootstrap completes on ia64 and x86_64 with the pass enabled.
TODO:
- remove_reachable_equiv_notes is an incomprehensible pile of goo and
a compile time hog that needs a rewrite (maybe cache st_exprs to
invalidate REG_EQUAL/REG_EQUIV notes for?).
- pattern_regs in st_expr should be a regset (on its own obstack).
- antic_stores and avail_stores should be VECs instead of lists.
- store_motion_mems should be a vec instead of a list.
- there should be an alloc pool for struct st_expr objects.
- investigate whether it is helpful to make the address of an st_expr
a cselib VALUE.
- when GIMPLE alias information is exported, the effectiveness of this
pass should be re-evaluated.
This is a list of store expressions (MEMs). The structure is used as an expression table to track stores which look interesting, and might be moveable towards the exit block.
Field Documentation
| rtx st_expr::antic_stores |
INSN list of stores that are locally anticipatable.
Referenced by compute_store_table(), find_moveable_store(), insert_store(), and store_killed_before().
| rtx st_expr::avail_stores |
INSN list of stores that are locally available.
| unsigned int st_expr::hash_index |
Hash value for the hash table.
| int st_expr::index |
Store ID in the dataflow bitmaps.
Referenced by insert_insn_start_basic_block(), and insert_store().
| struct st_expr* st_expr::next |
Next in the list.
| rtx st_expr::pattern |
Pattern of this mem.
Referenced by insert_store().
| rtx st_expr::pattern_regs |
List of registers mentioned by the mem.
Referenced by store_killed_before().
| rtx st_expr::reaching_reg |
Register holding the stored expression when a store is moved.
This field is also used as a cache in find_moveable_store, see
LAST_AVAIL_CHECK_FAILURE below.
The documentation for this struct was generated from the following file:
