aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.2.1-5666.3/gcc/tree-ssa-copyrename.c
diff options
context:
space:
mode:
Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/tree-ssa-copyrename.c')
-rw-r--r--gcc-4.2.1-5666.3/gcc/tree-ssa-copyrename.c404
1 files changed, 0 insertions, 404 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/tree-ssa-copyrename.c b/gcc-4.2.1-5666.3/gcc/tree-ssa-copyrename.c
deleted file mode 100644
index 45f65678e..000000000
--- a/gcc-4.2.1-5666.3/gcc/tree-ssa-copyrename.c
+++ /dev/null
@@ -1,404 +0,0 @@
-/* Rename SSA copies.
- Copyright (C) 2004 Free Software Foundation, Inc.
- Contributed by Andrew MacLeod <amacleod@redhat.com>
-
-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 2, 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 COPYING. If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
-
-#include "config.h"
-#include "system.h"
-#include "coretypes.h"
-#include "tm.h"
-#include "tree.h"
-#include "flags.h"
-#include "basic-block.h"
-#include "function.h"
-#include "diagnostic.h"
-#include "bitmap.h"
-#include "tree-flow.h"
-#include "tree-gimple.h"
-#include "tree-inline.h"
-#include "timevar.h"
-#include "hashtab.h"
-#include "tree-dump.h"
-#include "tree-ssa-live.h"
-#include "tree-pass.h"
-#include "langhooks.h"
-
-/* The following routines implement the SSA copy renaming phase.
-
- This optimization looks for copies between 2 SSA_NAMES, either through a
- direct copy, or an implicit one via a PHI node result and its arguments.
-
- Each copy is examined to determine if it is possible to rename the base
- variable of one of the operands to the same variable as the other operand.
- i.e.
- T.3_5 = <blah>
- a_1 = T.3_5
-
- If this copy couldn't be copy propagated, it could possibly remain in the
- program throughout the optimization phases. After SSA->normal, it would
- become:
-
- T.3 = <blah>
- a = T.3
-
- Since T.3_5 is distinct from all other SSA versions of T.3, there is no
- fundamental reason why the base variable needs to be T.3, subject to
- certain restrictions. This optimization attempts to determine if we can
- change the base variable on copies like this, and result in code such as:
-
- a_5 = <blah>
- a_1 = a_5
-
- This gives the SSA->normal pass a shot at coalescing a_1 and a_5. If it is
- possible, the copy goes away completely. If it isn't possible, a new temp
- will be created for a_5, and you will end up with the exact same code:
-
- a.8 = <blah>
- a = a.8
-
- The other benefit of performing this optimization relates to what variables
- are chosen in copies. Gimplification of the program uses temporaries for
- a lot of things. expressions like
-
- a_1 = <blah>
- <blah2> = a_1
-
- get turned into
-
- T.3_5 = <blah>
- a_1 = T.3_5
- <blah2> = a_1
-
- Copy propagation is done in a forward direction, and if we can propagate
- through the copy, we end up with:
-
- T.3_5 = <blah>
- <blah2> = T.3_5
-
- The copy is gone, but so is all reference to the user variable 'a'. By
- performing this optimization, we would see the sequence:
-
- a_5 = <blah>
- a_1 = a_5
- <blah2> = a_1
-
- which copy propagation would then turn into:
-
- a_5 = <blah>
- <blah2> = a_5
-
- and so we still retain the user variable whenever possible. */
-
-
-/* Coalesce the partitions in MAP representing VAR1 and VAR2 if it is valid.
- Choose a representative for the partition, and send debug info to DEBUG. */
-
-static void
-copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
-{
- int p1, p2, p3;
- tree root1, root2;
- tree rep1, rep2;
- var_ann_t ann1, ann2, ann3;
- bool ign1, ign2, abnorm;
-
- gcc_assert (TREE_CODE (var1) == SSA_NAME);
- gcc_assert (TREE_CODE (var2) == SSA_NAME);
-
- register_ssa_partition (map, var1, false);
- register_ssa_partition (map, var2, true);
-
- p1 = partition_find (map->var_partition, SSA_NAME_VERSION (var1));
- p2 = partition_find (map->var_partition, SSA_NAME_VERSION (var2));
-
- if (debug)
- {
- fprintf (debug, "Try : ");
- print_generic_expr (debug, var1, TDF_SLIM);
- fprintf (debug, "(P%d) & ", p1);
- print_generic_expr (debug, var2, TDF_SLIM);
- fprintf (debug, "(P%d)", p2);
- }
-
- gcc_assert (p1 != NO_PARTITION);
- gcc_assert (p2 != NO_PARTITION);
-
- rep1 = partition_to_var (map, p1);
- rep2 = partition_to_var (map, p2);
- root1 = SSA_NAME_VAR (rep1);
- root2 = SSA_NAME_VAR (rep2);
-
- ann1 = var_ann (root1);
- ann2 = var_ann (root2);
-
- if (p1 == p2)
- {
- if (debug)
- fprintf (debug, " : Already coalesced.\n");
- return;
- }
-
- /* Don't coalesce if one of the variables occurs in an abnormal PHI. */
- abnorm = (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep1)
- || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep2));
- if (abnorm)
- {
- if (debug)
- fprintf (debug, " : Abnormal PHI barrier. No coalesce.\n");
- return;
- }
-
- /* Partitions already have the same root, simply merge them. */
- if (root1 == root2)
- {
- p1 = partition_union (map->var_partition, p1, p2);
- if (debug)
- fprintf (debug, " : Same root, coalesced --> P%d.\n", p1);
- return;
- }
-
- /* Never attempt to coalesce 2 difference parameters. */
- if (TREE_CODE (root1) == PARM_DECL && TREE_CODE (root2) == PARM_DECL)
- {
- if (debug)
- fprintf (debug, " : 2 different PARM_DECLS. No coalesce.\n");
- return;
- }
-
- if ((TREE_CODE (root1) == RESULT_DECL) != (TREE_CODE (root2) == RESULT_DECL))
- {
- if (debug)
- fprintf (debug, " : One root a RESULT_DECL. No coalesce.\n");
- return;
- }
-
- ign1 = TREE_CODE (root1) == VAR_DECL && DECL_IGNORED_P (root1);
- ign2 = TREE_CODE (root2) == VAR_DECL && DECL_IGNORED_P (root2);
-
- /* Never attempt to coalesce 2 user variables unless one is an inline
- variable. */
- if (!ign1 && !ign2)
- {
- if (DECL_FROM_INLINE (root2))
- ign2 = true;
- else if (DECL_FROM_INLINE (root1))
- ign1 = true;
- else
- {
- if (debug)
- fprintf (debug, " : 2 different USER vars. No coalesce.\n");
- return;
- }
- }
-
- /* Don't coalesce if there are two different memory tags. */
- if (ann1->symbol_mem_tag
- && ann2->symbol_mem_tag
- && ann1->symbol_mem_tag != ann2->symbol_mem_tag)
- {
- if (debug)
- fprintf (debug, " : 2 memory tags. No coalesce.\n");
- return;
- }
-
- /* If both values have default defs, we can't coalesce. If only one has a
- tag, make sure that variable is the new root partition. */
- if (default_def (root1))
- {
- if (default_def (root2))
- {
- if (debug)
- fprintf (debug, " : 2 default defs. No coalesce.\n");
- return;
- }
- else
- {
- ign2 = true;
- ign1 = false;
- }
- }
- else if (default_def (root2))
- {
- ign1 = true;
- ign2 = false;
- }
-
- /* Don't coalesce if the two variables aren't type compatible. */
- if (!lang_hooks.types_compatible_p (TREE_TYPE (root1), TREE_TYPE (root2)))
- {
- if (debug)
- fprintf (debug, " : Incompatible types. No coalesce.\n");
- return;
- }
-
- /* Don't coalesce if the aliasing sets of the types are different. */
- if (POINTER_TYPE_P (TREE_TYPE (root1))
- && POINTER_TYPE_P (TREE_TYPE (root2))
- && get_alias_set (TREE_TYPE (TREE_TYPE (root1)))
- != get_alias_set (TREE_TYPE (TREE_TYPE (root2))))
- {
- if (debug)
- fprintf (debug, " : 2 different aliasing sets. No coalesce.\n");
- return;
- }
-
-
- /* Merge the two partitions. */
- p3 = partition_union (map->var_partition, p1, p2);
-
- /* Set the root variable of the partition to the better choice, if there is
- one. */
- if (!ign2)
- replace_ssa_name_symbol (partition_to_var (map, p3), root2);
- else if (!ign1)
- replace_ssa_name_symbol (partition_to_var (map, p3), root1);
-
- /* Update the various flag widgitry of the current base representative. */
- ann3 = var_ann (SSA_NAME_VAR (partition_to_var (map, p3)));
- if (ann1->symbol_mem_tag)
- ann3->symbol_mem_tag = ann1->symbol_mem_tag;
- else
- ann3->symbol_mem_tag = ann2->symbol_mem_tag;
-
- if (debug)
- {
- fprintf (debug, " --> P%d ", p3);
- print_generic_expr (debug, SSA_NAME_VAR (partition_to_var (map, p3)),
- TDF_SLIM);
- fprintf (debug, "\n");
- }
-}
-
-
-/* This function will make a pass through the IL, and attempt to coalesce any
- SSA versions which occur in PHI's or copies. Coalescing is accomplished by
- changing the underlying root variable of all coalesced version. This will
- then cause the SSA->normal pass to attempt to coalesce them all to the same
- variable. */
-
-static unsigned int
-rename_ssa_copies (void)
-{
- var_map map;
- basic_block bb;
- block_stmt_iterator bsi;
- tree phi, stmt, var, part_var;
- unsigned x;
- FILE *debug;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- debug = dump_file;
- else
- debug = NULL;
-
- map = init_var_map (num_ssa_names + 1);
-
- FOR_EACH_BB (bb)
- {
- /* Scan for real copies. */
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- stmt = bsi_stmt (bsi);
- if (TREE_CODE (stmt) == MODIFY_EXPR)
- {
- tree lhs = TREE_OPERAND (stmt, 0);
- tree rhs = TREE_OPERAND (stmt, 1);
-
- if (TREE_CODE (lhs) == SSA_NAME && TREE_CODE (rhs) == SSA_NAME)
- copy_rename_partition_coalesce (map, lhs, rhs, debug);
- }
- }
- }
-
- FOR_EACH_BB (bb)
- {
- /* Treat PHI nodes as copies between the result and each argument. */
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- int i;
- tree res = PHI_RESULT (phi);
-
- /* Do not process virtual SSA_NAMES. */
- if (!is_gimple_reg (SSA_NAME_VAR (res)))
- continue;
-
- for (i = 0; i < PHI_NUM_ARGS (phi); i++)
- {
- tree arg = PHI_ARG_DEF (phi, i);
- if (TREE_CODE (arg) == SSA_NAME)
- copy_rename_partition_coalesce (map, res, arg, debug);
- }
- }
- }
-
- if (debug)
- dump_var_map (debug, map);
-
- /* Now one more pass to make all elements of a partition share the same
- root variable. */
-
- for (x = 1; x <= num_ssa_names; x++)
- {
- part_var = partition_to_var (map, x);
- if (!part_var)
- continue;
- var = map->partition_to_var[x];
- if (debug)
- {
- if (SSA_NAME_VAR (var) != SSA_NAME_VAR (part_var))
- {
- fprintf (debug, "Coalesced ");
- print_generic_expr (debug, var, TDF_SLIM);
- fprintf (debug, " to ");
- print_generic_expr (debug, part_var, TDF_SLIM);
- fprintf (debug, "\n");
- }
- }
- replace_ssa_name_symbol (var, SSA_NAME_VAR (part_var));
- }
-
- delete_var_map (map);
- return 0;
-}
-
-/* Return true if copy rename is to be performed. */
-
-static bool
-gate_copyrename (void)
-{
- return flag_tree_copyrename != 0;
-}
-
-struct tree_opt_pass pass_rename_ssa_copies =
-{
- "copyrename", /* name */
- gate_copyrename, /* gate */
- rename_ssa_copies, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_TREE_COPY_RENAME, /* tv_id */
- PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_dump_func | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
-};
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-20 01:47:17 +0000