/* SSA Dominator optimizations for trees
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@redhat.com>
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)
+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,
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. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
expressions are removed from AVAIL_EXPRS. Else we may change the
hash code for an expression and be unable to find/remove it from
AVAIL_EXPRS. */
-static VEC(tree,heap) *stmts_to_rescan;
+typedef tree *tree_p;
+DEF_VEC_P(tree_p);
+DEF_VEC_ALLOC_P(tree_p,heap);
+
+static VEC(tree_p,heap) *stmts_to_rescan;
/* Structure for entries in the expression hash table.
{
struct dom_walk_data walk_data;
unsigned int i;
- struct loops loops_info;
memset (&opt_stats, 0, sizeof (opt_stats));
avail_exprs = htab_create (1024, real_avail_expr_hash, avail_expr_eq, free);
avail_exprs_stack = VEC_alloc (tree, heap, 20);
const_and_copies_stack = VEC_alloc (tree, heap, 20);
- stmts_to_rescan = VEC_alloc (tree, heap, 20);
+ stmts_to_rescan = VEC_alloc (tree_p, heap, 20);
need_eh_cleanup = BITMAP_ALLOC (NULL);
/* Setup callbacks for the generic dominator tree walker. */
init_walk_dominator_tree (&walk_data);
calculate_dominance_info (CDI_DOMINATORS);
+ cfg_altered = false;
- /* We need to know which edges exit loops so that we can
- aggressively thread through loop headers to an exit
- edge. */
- flow_loops_find (&loops_info);
- mark_loop_exit_edges (&loops_info);
- flow_loops_free (&loops_info);
-
- /* Clean up the CFG so that any forwarder blocks created by loop
- canonicalization are removed. */
- cleanup_tree_cfg ();
- calculate_dominance_info (CDI_DOMINATORS);
+ /* We need to know loop structures in order to avoid destroying them
+ in jump threading. Note that we still can e.g. thread through loop
+ headers to an exit edge, or through loop header to the loop body, assuming
+ that we update the loop info. */
+ loop_optimizer_init (LOOPS_HAVE_SIMPLE_LATCHES);
/* We need accurate information regarding back edges in the CFG
- for jump threading. */
+ for jump threading; this may include back edes that are not part of
+ a single loop. */
mark_dfs_back_edges ();
-
+
/* Recursively walk the dominator tree optimizing statements. */
walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
free_all_edge_infos ();
/* Thread jumps, creating duplicate blocks as needed. */
- cfg_altered |= thread_through_all_blocks ();
+ cfg_altered |= thread_through_all_blocks (first_pass_instance);
+
+ if (cfg_altered)
+ free_dominance_info (CDI_DOMINATORS);
/* Removal of statements may make some EH edges dead. Purge
such edges from the CFG as needed. */
if (!bitmap_empty_p (need_eh_cleanup))
{
- cfg_altered |= tree_purge_all_dead_eh_edges (need_eh_cleanup);
+ tree_purge_all_dead_eh_edges (need_eh_cleanup);
bitmap_zero (need_eh_cleanup);
}
- if (cfg_altered)
- free_dominance_info (CDI_DOMINATORS);
-
/* Finally, remove everything except invariants in SSA_NAME_VALUE.
Long term we will be able to let everything in SSA_NAME_VALUE
if (dump_file && (dump_flags & TDF_STATS))
dump_dominator_optimization_stats (dump_file);
+ loop_optimizer_finalize ();
+
/* Delete our main hashtable. */
htab_delete (avail_exprs);
VEC_free (tree, heap, avail_exprs_stack);
VEC_free (tree, heap, const_and_copies_stack);
- VEC_free (tree, heap, stmts_to_rescan);
+ VEC_free (tree_p, heap, stmts_to_rescan);
return 0;
}
return flag_tree_dom != 0;
}
-struct tree_opt_pass pass_dominator =
+struct gimple_opt_pass pass_dominator =
{
+ {
+ GIMPLE_PASS,
"dom", /* name */
gate_dominator, /* gate */
tree_ssa_dominator_optimize, /* execute */
TV_TREE_SSA_DOMINATOR_OPTS, /* tv_id */
PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
0, /* properties_provided */
- PROP_smt_usage, /* properties_destroyed */
+ 0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_dump_func
| TODO_update_ssa
| TODO_cleanup_cfg
- | TODO_verify_ssa
- | TODO_update_smt_usage, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_ssa /* todo_flags_finish */
+ }
};
else if (TREE_CODE (expr) == RETURN_EXPR && TREE_OPERAND (expr, 0))
{
element->stmt = expr;
- element->rhs = TREE_OPERAND (TREE_OPERAND (expr, 0), 1);
+ element->rhs = GIMPLE_STMT_OPERAND (TREE_OPERAND (expr, 0), 1);
}
else if (TREE_CODE (expr) == GOTO_EXPR)
{
else
{
element->stmt = expr;
- element->rhs = TREE_OPERAND (expr, 1);
+ element->rhs = GENERIC_TREE_OPERAND (expr, 1);
}
element->lhs = lhs;
/* A trivial wrapper so that we can present the generic jump
threading code with a simple API for simplifying statements. */
static tree
-simplify_stmt_for_jump_threading (tree stmt)
+simplify_stmt_for_jump_threading (tree stmt, tree within_stmt ATTRIBUTE_UNUSED)
{
return lookup_avail_expr (stmt, false);
}
walk_data->global_data = dummy_cond;
}
- thread_across_edge (walk_data->global_data, e, false,
+ thread_across_edge ((tree) walk_data->global_data, e, false,
&const_and_copies_stack,
simplify_stmt_for_jump_threading);
}
/* If we queued any statements to rescan in this block, then
go ahead and rescan them now. */
- while (VEC_length (tree, stmts_to_rescan) > 0)
+ while (VEC_length (tree_p, stmts_to_rescan) > 0)
{
- tree stmt = VEC_last (tree, stmts_to_rescan);
+ tree *stmt_p = VEC_last (tree_p, stmts_to_rescan);
+ tree stmt = *stmt_p;
basic_block stmt_bb = bb_for_stmt (stmt);
if (stmt_bb != bb)
break;
- VEC_pop (tree, stmts_to_rescan);
- mark_new_vars_to_rename (stmt);
+ VEC_pop (tree_p, stmts_to_rescan);
+ pop_stmt_changes (stmt_p);
}
}
{
case LT_EXPR:
case GT_EXPR:
- edge_info->max_cond_equivalences = 12;
- edge_info->cond_equivalences = XNEWVEC (tree, 12);
+ if (FLOAT_TYPE_P (TREE_TYPE (op0)))
+ {
+ edge_info->max_cond_equivalences = 12;
+ edge_info->cond_equivalences = XNEWVEC (tree, 12);
+ build_and_record_new_cond (ORDERED_EXPR, op0, op1,
+ &edge_info->cond_equivalences[8]);
+ build_and_record_new_cond (LTGT_EXPR, op0, op1,
+ &edge_info->cond_equivalences[10]);
+ }
+ else
+ {
+ edge_info->max_cond_equivalences = 8;
+ edge_info->cond_equivalences = XNEWVEC (tree, 8);
+ }
+
build_and_record_new_cond ((TREE_CODE (cond) == LT_EXPR
? LE_EXPR : GE_EXPR),
op0, op1, &edge_info->cond_equivalences[4]);
- build_and_record_new_cond (ORDERED_EXPR, op0, op1,
- &edge_info->cond_equivalences[6]);
build_and_record_new_cond (NE_EXPR, op0, op1,
- &edge_info->cond_equivalences[8]);
- build_and_record_new_cond (LTGT_EXPR, op0, op1,
- &edge_info->cond_equivalences[10]);
+ &edge_info->cond_equivalences[6]);
break;
case GE_EXPR:
case LE_EXPR:
- edge_info->max_cond_equivalences = 6;
- edge_info->cond_equivalences = XNEWVEC (tree, 6);
- build_and_record_new_cond (ORDERED_EXPR, op0, op1,
- &edge_info->cond_equivalences[4]);
+ if (FLOAT_TYPE_P (TREE_TYPE (op0)))
+ {
+ edge_info->max_cond_equivalences = 6;
+ edge_info->cond_equivalences = XNEWVEC (tree, 6);
+ build_and_record_new_cond (ORDERED_EXPR, op0, op1,
+ &edge_info->cond_equivalences[4]);
+ }
+ else
+ {
+ edge_info->max_cond_equivalences = 4;
+ edge_info->cond_equivalences = XNEWVEC (tree, 4);
+ }
break;
case EQ_EXPR:
- edge_info->max_cond_equivalences = 10;
- edge_info->cond_equivalences = XNEWVEC (tree, 10);
- build_and_record_new_cond (ORDERED_EXPR, op0, op1,
- &edge_info->cond_equivalences[4]);
+ if (FLOAT_TYPE_P (TREE_TYPE (op0)))
+ {
+ edge_info->max_cond_equivalences = 10;
+ edge_info->cond_equivalences = XNEWVEC (tree, 10);
+ build_and_record_new_cond (ORDERED_EXPR, op0, op1,
+ &edge_info->cond_equivalences[8]);
+ }
+ else
+ {
+ edge_info->max_cond_equivalences = 8;
+ edge_info->cond_equivalences = XNEWVEC (tree, 8);
+ }
build_and_record_new_cond (LE_EXPR, op0, op1,
- &edge_info->cond_equivalences[6]);
+ &edge_info->cond_equivalences[4]);
build_and_record_new_cond (GE_EXPR, op0, op1,
- &edge_info->cond_equivalences[8]);
+ &edge_info->cond_equivalences[6]);
break;
case UNORDERED_EXPR:
tree lhs, rhs, preinc, phi;
unsigned i;
- if (TREE_CODE (stmt) != MODIFY_EXPR)
+ if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
return false;
- lhs = TREE_OPERAND (stmt, 0);
+ lhs = GIMPLE_STMT_OPERAND (stmt, 0);
if (TREE_CODE (lhs) != SSA_NAME)
return false;
- rhs = TREE_OPERAND (stmt, 1);
+ rhs = GIMPLE_STMT_OPERAND (stmt, 1);
if (TREE_CODE (rhs) != PLUS_EXPR
&& TREE_CODE (rhs) != MINUS_EXPR)
indx = e->dest_idx;
for ( ; phi; phi = PHI_CHAIN (phi))
{
- tree new;
+ tree new_val;
use_operand_p orig_p;
- tree orig;
+ tree orig_val;
/* The alternative may be associated with a constant, so verify
it is an SSA_NAME before doing anything with it. */
orig_p = PHI_ARG_DEF_PTR (phi, indx);
- orig = USE_FROM_PTR (orig_p);
- if (TREE_CODE (orig) != SSA_NAME)
+ orig_val = USE_FROM_PTR (orig_p);
+ if (TREE_CODE (orig_val) != SSA_NAME)
continue;
/* If we have *ORIG_P in our constant/copy table, then replace
ORIG_P with its value in our constant/copy table. */
- new = SSA_NAME_VALUE (orig);
- if (new
- && new != orig
- && (TREE_CODE (new) == SSA_NAME
- || is_gimple_min_invariant (new))
- && may_propagate_copy (orig, new))
- propagate_value (orig_p, new);
+ new_val = SSA_NAME_VALUE (orig_val);
+ if (new_val
+ && new_val != orig_val
+ && (TREE_CODE (new_val) == SSA_NAME
+ || is_gimple_min_invariant (new_val))
+ && may_propagate_copy (orig_val, new_val))
+ propagate_value (orig_p, new_val);
}
}
}
bool retval = false;
bool modify_expr_p = false;
- if (TREE_CODE (stmt) == MODIFY_EXPR)
- def = TREE_OPERAND (stmt, 0);
+ if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+ def = GIMPLE_STMT_OPERAND (stmt, 0);
/* Certain expressions on the RHS can be optimized away, but can not
themselves be entered into the hash tables. */
if (! def
|| TREE_CODE (def) != SSA_NAME
|| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def)
- || !ZERO_SSA_OPERANDS (stmt, SSA_OP_VMAYDEF)
+ || !ZERO_SSA_OPERANDS (stmt, SSA_OP_VDEF)
/* Do not record equivalences for increments of ivs. This would create
overlapping live ranges for a very questionable gain. */
|| simple_iv_increment_p (stmt))
expr_p = &SWITCH_COND (stmt);
else if (TREE_CODE (stmt) == RETURN_EXPR && TREE_OPERAND (stmt, 0))
{
- expr_p = &TREE_OPERAND (TREE_OPERAND (stmt, 0), 1);
+ expr_p = &GIMPLE_STMT_OPERAND (TREE_OPERAND (stmt, 0), 1);
modify_expr_p = true;
}
else
{
- expr_p = &TREE_OPERAND (stmt, 1);
+ expr_p = &GENERIC_TREE_OPERAND (stmt, 1);
modify_expr_p = true;
}
if (cached_lhs
&& ((TREE_CODE (cached_lhs) != SSA_NAME
&& (modify_expr_p
- || tree_ssa_useless_type_conversion_1 (TREE_TYPE (*expr_p),
- TREE_TYPE (cached_lhs))))
+ || useless_type_conversion_p (TREE_TYPE (*expr_p),
+ TREE_TYPE (cached_lhs))))
|| may_propagate_copy (*expr_p, cached_lhs)))
{
if (dump_file && (dump_flags & TDF_DETAILS))
retval = true;
if (modify_expr_p
- && !tree_ssa_useless_type_conversion_1 (TREE_TYPE (*expr_p),
- TREE_TYPE (cached_lhs)))
+ && !useless_type_conversion_p (TREE_TYPE (*expr_p),
+ TREE_TYPE (cached_lhs)))
cached_lhs = fold_convert (TREE_TYPE (*expr_p), cached_lhs);
propagate_tree_value (expr_p, cached_lhs);
return retval;
}
-/* STMT, a MODIFY_EXPR, may create certain equivalences, in either
+/* STMT, a GIMPLE_MODIFY_STMT, may create certain equivalences, in either
the available expressions table or the const_and_copies table.
Detect and record those equivalences. */
static void
-record_equivalences_from_stmt (tree stmt,
- int may_optimize_p,
- stmt_ann_t ann)
+record_equivalences_from_stmt (tree stmt, int may_optimize_p, stmt_ann_t ann)
{
- tree lhs = TREE_OPERAND (stmt, 0);
+ tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
enum tree_code lhs_code = TREE_CODE (lhs);
if (lhs_code == SSA_NAME)
{
- tree rhs = TREE_OPERAND (stmt, 1);
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
/* Strip away any useless type conversions. */
STRIP_USELESS_TYPE_CONVERSION (rhs);
vops and recording the result in the available expression table,
we may be able to expose more redundant loads. */
if (!ann->has_volatile_ops
- && (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME
- || is_gimple_min_invariant (TREE_OPERAND (stmt, 1)))
+ && stmt_references_memory_p (stmt)
+ && (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == SSA_NAME
+ || is_gimple_min_invariant (GIMPLE_STMT_OPERAND (stmt, 1)))
&& !is_gimple_reg (lhs))
{
- tree rhs = TREE_OPERAND (stmt, 1);
- tree new;
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
+ tree new_stmt;
/* FIXME: If the LHS of the assignment is a bitfield and the RHS
is a constant, we need to adjust the constant to fit into the
if (rhs)
{
/* Build a new statement with the RHS and LHS exchanged. */
- new = build2 (MODIFY_EXPR, TREE_TYPE (stmt), rhs, lhs);
+ new_stmt = build_gimple_modify_stmt (rhs, lhs);
- create_ssa_artficial_load_stmt (new, stmt);
+ create_ssa_artificial_load_stmt (new_stmt, stmt, true);
/* Finally enter the statement into the available expression
table. */
- lookup_avail_expr (new, true);
+ lookup_avail_expr (new_stmt, true);
}
}
}
propagation opportunity. */
if (TREE_CODE (val) != SSA_NAME)
{
- if (!lang_hooks.types_compatible_p (op_type, val_type))
+ if (!useless_type_conversion_p (op_type, val_type))
{
val = fold_convert (TREE_TYPE (op), val);
if (!is_gimple_min_invariant (val))
known value for that SSA_NAME (or NULL if no value is known).
Propagate values from CONST_AND_COPIES into the uses, vuses and
- v_may_def_ops of STMT. */
+ vdef_ops of STMT. */
static bool
cprop_into_stmt (tree stmt)
ann = stmt_ann (stmt);
opt_stats.num_stmts++;
may_have_exposed_new_symbols = false;
+ push_stmt_changes (bsi_stmt_ptr (si));
if (dump_file && (dump_flags & TDF_DETAILS))
{
print_generic_stmt (dump_file, stmt, TDF_SLIM);
}
- /* Const/copy propagate into USES, VUSES and the RHS of V_MAY_DEFs. */
+ /* Const/copy propagate into USES, VUSES and the RHS of VDEFs. */
may_have_exposed_new_symbols = cprop_into_stmt (stmt);
/* If the statement has been modified with constant replacements,
may_optimize_p = (!ann->has_volatile_ops
&& ((TREE_CODE (stmt) == RETURN_EXPR
&& TREE_OPERAND (stmt, 0)
- && TREE_CODE (TREE_OPERAND (stmt, 0)) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (stmt, 0))
+ == GIMPLE_MODIFY_STMT
&& ! (TREE_SIDE_EFFECTS
- (TREE_OPERAND (TREE_OPERAND (stmt, 0), 1))))
- || (TREE_CODE (stmt) == MODIFY_EXPR
- && ! TREE_SIDE_EFFECTS (TREE_OPERAND (stmt, 1)))
+ (GIMPLE_STMT_OPERAND
+ (TREE_OPERAND (stmt, 0), 1))))
+ || (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
+ && ! TREE_SIDE_EFFECTS (GIMPLE_STMT_OPERAND (stmt,
+ 1)))
|| TREE_CODE (stmt) == COND_EXPR
|| TREE_CODE (stmt) == SWITCH_EXPR));
may_have_exposed_new_symbols |= eliminate_redundant_computations (stmt);
/* Record any additional equivalences created by this statement. */
- if (TREE_CODE (stmt) == MODIFY_EXPR)
- record_equivalences_from_stmt (stmt,
- may_optimize_p,
- ann);
+ if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+ record_equivalences_from_stmt (stmt, may_optimize_p, ann);
/* If STMT is a COND_EXPR and it was modified, then we may know
where it goes. If that is the case, then mark the CFG as altered.
Ultimately I suspect we're going to need to change the interface
into the SSA_NAME manager. */
-
if (ann->modified)
{
tree val = NULL;
}
if (may_have_exposed_new_symbols)
- VEC_safe_push (tree, heap, stmts_to_rescan, bsi_stmt (si));
+ {
+ /* Queue the statement to be re-scanned after all the
+ AVAIL_EXPRS have been processed. The change buffer stack for
+ all the pushed statements will be processed when this queue
+ is emptied. */
+ VEC_safe_push (tree_p, heap, stmts_to_rescan, bsi_stmt_ptr (si));
+ }
+ else
+ {
+ /* Otherwise, just discard the recently pushed change buffer. If
+ not, the STMTS_TO_RESCAN queue will get out of synch with the
+ change buffer stack. */
+ discard_stmt_changes (bsi_stmt_ptr (si));
+ }
}
/* Search for an existing instance of STMT in the AVAIL_EXPRS table. If
is also added to the stack pointed to by BLOCK_AVAIL_EXPRS_P, so that they
can be removed when we finish processing this block and its children.
- NOTE: This function assumes that STMT is a MODIFY_EXPR node that
+ NOTE: This function assumes that STMT is a GIMPLE_MODIFY_STMT node that
contains no CALL_EXPR on its RHS and makes no volatile nor
aliased references. */
tree temp;
struct expr_hash_elt *element = XNEW (struct expr_hash_elt);
- lhs = TREE_CODE (stmt) == MODIFY_EXPR ? TREE_OPERAND (stmt, 0) : NULL;
+ lhs = TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
+ ? GIMPLE_STMT_OPERAND (stmt, 0) : NULL;
initialize_hash_element (stmt, lhs, element);
}
/* Hashing and equality functions for AVAIL_EXPRS. The table stores
- MODIFY_EXPR statements. We compute a value number for expressions using
- the code of the expression and the SSA numbers of its operands. */
+ GIMPLE_MODIFY_STMT statements. We compute a value number for expressions
+ using the code of the expression and the SSA numbers of its operands. */
static hashval_t
avail_expr_hash (const void *p)
{
- tree stmt = ((struct expr_hash_elt *)p)->stmt;
- tree rhs = ((struct expr_hash_elt *)p)->rhs;
+ tree stmt = ((const struct expr_hash_elt *)p)->stmt;
+ tree rhs = ((const struct expr_hash_elt *)p)->rhs;
tree vuse;
ssa_op_iter iter;
hashval_t val = 0;
static int
avail_expr_eq (const void *p1, const void *p2)
{
- tree stmt1 = ((struct expr_hash_elt *)p1)->stmt;
- tree rhs1 = ((struct expr_hash_elt *)p1)->rhs;
- tree stmt2 = ((struct expr_hash_elt *)p2)->stmt;
- tree rhs2 = ((struct expr_hash_elt *)p2)->rhs;
+ tree stmt1 = ((const struct expr_hash_elt *)p1)->stmt;
+ tree rhs1 = ((const struct expr_hash_elt *)p1)->rhs;
+ tree stmt2 = ((const struct expr_hash_elt *)p2)->stmt;
+ tree rhs2 = ((const struct expr_hash_elt *)p2)->rhs;
/* If they are the same physical expression, return true. */
if (rhs1 == rhs2 && stmt1 == stmt2)
/* In case of a collision, both RHS have to be identical and have the
same VUSE operands. */
- if ((TREE_TYPE (rhs1) == TREE_TYPE (rhs2)
- || lang_hooks.types_compatible_p (TREE_TYPE (rhs1), TREE_TYPE (rhs2)))
+ if (types_compatible_p (TREE_TYPE (rhs1), TREE_TYPE (rhs2))
&& operand_equal_p (rhs1, rhs2, OEP_PURE_SAME))
{
bool ret = compare_ssa_operands_equal (stmt1, stmt2, SSA_OP_VUSE);
- gcc_assert (!ret || ((struct expr_hash_elt *)p1)->hash
- == ((struct expr_hash_elt *)p2)->hash);
+ gcc_assert (!ret || ((const struct expr_hash_elt *)p1)->hash
+ == ((const struct expr_hash_elt *)p2)->hash);
return ret;
}
return (i == PHI_NUM_ARGS (phi) ? val : NULL);
}
-/* Given a tree node T, which is either a PHI_NODE or MODIFY_EXPR,
+/* Given a tree node T, which is either a PHI_NODE or GIMPLE_MODIFY_STMT,
remove it from the IL. */
static void
remove_stmt_or_phi (tree t)
{
if (TREE_CODE (t) == PHI_NODE)
- remove_phi_node (t, NULL);
+ remove_phi_node (t, NULL, true);
else
{
block_stmt_iterator bsi = bsi_for_stmt (t);
bsi_remove (&bsi, true);
+ release_defs (t);
}
}
-/* Given a tree node T, which is either a PHI_NODE or MODIFY_EXPR,
+/* Given a tree node T, which is either a PHI_NODE or GIMPLE_MODIFY_STMT,
return the "rhs" of the node, in the case of a non-degenerate
PHI, NULL is returned. */
{
if (TREE_CODE (t) == PHI_NODE)
return degenerate_phi_result (t);
- else if (TREE_CODE (t) == MODIFY_EXPR)
- return TREE_OPERAND (t, 1);
+ else if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
+ return GIMPLE_STMT_OPERAND (t, 1);
gcc_unreachable ();
}
-/* Given a tree node T, which is either a PHI_NODE or a MODIFY_EXPR,
+/* Given a tree node T, which is either a PHI_NODE or a GIMPLE_MODIFY_STMT,
return the "lhs" of the node. */
static tree
{
if (TREE_CODE (t) == PHI_NODE)
return PHI_RESULT (t);
- else if (TREE_CODE (t) == MODIFY_EXPR)
- return TREE_OPERAND (t, 0);
+ else if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
+ return GIMPLE_STMT_OPERAND (t, 0);
gcc_unreachable ();
}
{
use_operand_p use_p;
imm_use_iterator iter;
+ tree use_stmt;
bool all = true;
/* Dump details. */
/* Walk over every use of LHS and try to replace the use with RHS.
At this point the only reason why such a propagation would not
be successful would be if the use occurs in an ASM_EXPR. */
- repeat:
- FOR_EACH_IMM_USE_SAFE (use_p, iter, lhs)
+ FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
{
- tree use_stmt = USE_STMT (use_p);
/* It's not always safe to propagate into an ASM_EXPR. */
if (TREE_CODE (use_stmt) == ASM_EXPR
fprintf (dump_file, "\n");
}
- /* Propagate, fold and update the statement. Note this may
- expose new const/copy propagation opportunities as well
- collapse control statements. */
- propagate_value (use_p, rhs);
+ push_stmt_changes (&use_stmt);
+
+ /* Propagate the RHS into this use of the LHS. */
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ propagate_value (use_p, rhs);
+
+ /* Special cases to avoid useless calls into the folding
+ routines, operand scanning, etc.
+
+ First, propagation into a PHI may cause the PHI to become
+ a degenerate, so mark the PHI as interesting. No other
+ actions are necessary.
+
+ Second, if we're propagating a virtual operand and the
+ propagation does not change the underlying _DECL node for
+ the virtual operand, then no further actions are necessary. */
+ if (TREE_CODE (use_stmt) == PHI_NODE
+ || (! is_gimple_reg (lhs)
+ && TREE_CODE (rhs) == SSA_NAME
+ && SSA_NAME_VAR (lhs) == SSA_NAME_VAR (rhs)))
+ {
+ /* Dump details. */
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " Updated statement:");
+ print_generic_expr (dump_file, use_stmt, dump_flags);
+ fprintf (dump_file, "\n");
+ }
+
+ /* Propagation into a PHI may expose new degenerate PHIs,
+ so mark the result of the PHI as interesting. */
+ if (TREE_CODE (use_stmt) == PHI_NODE)
+ {
+ tree result = get_lhs_or_phi_result (use_stmt);
+ bitmap_set_bit (interesting_names, SSA_NAME_VERSION (result));
+ }
+
+ discard_stmt_changes (&use_stmt);
+ continue;
+ }
+
+ /* From this point onward we are propagating into a
+ real statement. Folding may (or may not) be possible,
+ we may expose new operands, expose dead EH edges,
+ etc. */
fold_stmt_inplace (use_stmt);
/* Sometimes propagation can expose new operands to the
renamer. Note this will call update_stmt at the
appropriate time. */
- mark_new_vars_to_rename (use_stmt);
+ pop_stmt_changes (&use_stmt);
/* Dump details. */
if (dump_file && (dump_flags & TDF_DETAILS))
/* If we replaced a variable index with a constant, then
we would need to update the invariant flag for ADDR_EXPRs. */
- if (TREE_CODE (use_stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (use_stmt, 1)) == ADDR_EXPR)
- recompute_tree_invariant_for_addr_expr (TREE_OPERAND (use_stmt, 1));
+ if (TREE_CODE (use_stmt) == GIMPLE_MODIFY_STMT
+ && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == ADDR_EXPR)
+ recompute_tree_invariant_for_addr_expr
+ (GIMPLE_STMT_OPERAND (use_stmt, 1));
/* If we cleaned up EH information from the statement,
mark its containing block as needing EH cleanups. */
fprintf (dump_file, " Flagged to clear EH edges.\n");
}
- /* Propagation may expose new degenerate PHIs or
- trivial copy/constant propagation opportunities. */
- if (TREE_CODE (use_stmt) == PHI_NODE
- || (TREE_CODE (use_stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (use_stmt, 0)) == SSA_NAME
- && (TREE_CODE (TREE_OPERAND (use_stmt, 1)) == SSA_NAME
- || is_gimple_min_invariant (TREE_OPERAND (use_stmt, 1)))))
+ /* Propagation may expose new trivial copy/constant propagation
+ opportunities. */
+ if (TREE_CODE (use_stmt) == GIMPLE_MODIFY_STMT
+ && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 0)) == SSA_NAME
+ && (TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == SSA_NAME
+ || is_gimple_min_invariant (GIMPLE_STMT_OPERAND (use_stmt,
+ 1))))
{
tree result = get_lhs_or_phi_result (use_stmt);
bitmap_set_bit (interesting_names, SSA_NAME_VERSION (result));
te->count += e->count;
remove_edge (e);
- cfg_altered = 1;
+ cfg_altered = true;
}
else
ei_next (&ei);
}
}
- /* Due to a bug in the immediate use iterator code, we can
- miss visiting uses in some cases when there is more than
- one use in a statement. Missing a use can cause a multitude
- of problems if we expected to eliminate all uses and remove
- the defining statement.
-
- Until Andrew can fix the iterator, this hack will detect
- the cases which cause us problems. Namely if ALL is set
- and we still have some immediate uses, then we must have
- skipped one or more in the loop above. So just re-execute
- the loop.
-
- The maximum number of times we can re-execute the loop is
- bounded by the maximum number of times a given SSA_NAME
- appears in a single statement. */
- if (all && num_imm_uses (lhs) != 0)
- goto repeat;
+ /* Ensure there is nothing else to do. */
+ gcc_assert (!all || has_zero_uses (lhs));
/* If we were able to propagate away all uses of LHS, then
we can remove STMT. */
}
}
-/* T is either a PHI node (potentally a degenerate PHI node) or
+/* T is either a PHI node (potentially a degenerate PHI node) or
a statement that is a trivial copy or constant initialization.
Attempt to eliminate T by propagating its RHS into all uses of
eliminate_degenerate_phis (void)
{
bitmap interesting_names;
+ bitmap interesting_names1;
/* Bitmap of blocks which need EH information updated. We can not
update it on-the-fly as doing so invalidates the dominator tree. */
A set bit indicates that the statement or PHI node which
defines the SSA_NAME should be (re)examined to determine if
- it has become a degenerate PHI or trival const/copy propagation
+ it has become a degenerate PHI or trivial const/copy propagation
opportunity.
Experiments have show we generally get better compilation
time behavior with bitmaps rather than sbitmaps. */
interesting_names = BITMAP_ALLOC (NULL);
+ interesting_names1 = BITMAP_ALLOC (NULL);
- /* First phase. Elimiante degenerate PHIs via a domiantor
+ calculate_dominance_info (CDI_DOMINATORS);
+ cfg_altered = false;
+
+ /* First phase. Eliminate degenerate PHIs via a dominator
walk of the CFG.
Experiments have indicated that we generally get better
phase in dominator order. Presumably this is because walking
in dominator order leaves fewer PHIs for later examination
by the worklist phase. */
- calculate_dominance_info (CDI_DOMINATORS);
eliminate_degenerate_phis_1 (ENTRY_BLOCK_PTR, interesting_names);
- /* Second phase. Eliminate second order degnerate PHIs as well
+ /* Second phase. Eliminate second order degenerate PHIs as well
as trivial copies or constant initializations identified by
the first phase or this phase. Basically we keep iterating
until our set of INTERESTING_NAMEs is empty. */
unsigned int i;
bitmap_iterator bi;
- EXECUTE_IF_SET_IN_BITMAP (interesting_names, 0, i, bi)
+ /* EXECUTE_IF_SET_IN_BITMAP does not like its bitmap
+ changed during the loop. Copy it to another bitmap and
+ use that. */
+ bitmap_copy (interesting_names1, interesting_names);
+
+ EXECUTE_IF_SET_IN_BITMAP (interesting_names1, 0, i, bi)
{
tree name = ssa_name (i);
}
}
+ if (cfg_altered)
+ free_dominance_info (CDI_DOMINATORS);
+
/* Propagation of const and copies may make some EH edges dead. Purge
such edges from the CFG as needed. */
if (!bitmap_empty_p (need_eh_cleanup))
{
- cfg_altered |= tree_purge_all_dead_eh_edges (need_eh_cleanup);
+ tree_purge_all_dead_eh_edges (need_eh_cleanup);
BITMAP_FREE (need_eh_cleanup);
}
BITMAP_FREE (interesting_names);
- if (cfg_altered)
- free_dominance_info (CDI_DOMINATORS);
+ BITMAP_FREE (interesting_names1);
return 0;
}
-struct tree_opt_pass pass_phi_only_cprop =
+struct gimple_opt_pass pass_phi_only_cprop =
{
+ {
+ GIMPLE_PASS,
"phicprop", /* name */
gate_dominator, /* gate */
eliminate_degenerate_phis, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- TV_TREE_CCP, /* tv_id */
+ TV_TREE_PHI_CPROP, /* tv_id */
PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
0, /* properties_provided */
- PROP_smt_usage, /* properties_destroyed */
+ 0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_cleanup_cfg | TODO_dump_func
- | TODO_ggc_collect | TODO_verify_ssa
- | TODO_verify_stmts | TODO_update_smt_usage
- | TODO_update_ssa, /* todo_flags_finish */
- 0 /* letter */
+ TODO_cleanup_cfg
+ | TODO_dump_func
+ | TODO_ggc_collect
+ | TODO_verify_ssa
+ | TODO_verify_stmts
+ | TODO_update_ssa /* todo_flags_finish */
+ }
};
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