procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

passes.c (init_optimization_passes): Add simple dce and addressable passes.

Browse source 
* passes.c (init_optimization_passes): Add simple dce and addressable
	passes.
	* tree-ssa.c (execute_update_addresses_taken): New function.
	(pass_update_address_taken): New.
	* tree-ssa-dse.c (execute_simple_dse): New function.
	(pass_simple_dse): New.
	* tree-pass.h (pass_simple_dse, pass_update_address_taken): Declare.

From-SVN: r128239
This commit is contained in:
Jan Hubicka 2007-09-07 13:28:35 +02:00 • committed by Jan Hubicka
parent f85138bc84
commit 201b2eadc4
5 changed files with 246 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
gcc/ChangeLog
View file

@ -1,3 +1,13 @@
2007-09-07 Jan Hubicka <jh@suse.cz>
* passes.c (init_optimization_passes): Add simple dce and addressable
passes.
* tree-ssa.c (execute_update_addresses_taken): New function.
(pass_update_address_taken): New.
* tree-ssa-dse.c (execute_simple_dse): New function.
(pass_simple_dse): New.
* tree-pass.h (pass_simple_dse, pass_update_address_taken): Declare.
2007-09-07 Tobias Burnus <burnus@net-b.de>
PR middle-end/33321

4
gcc/passes.c
View file

@ -523,10 +523,14 @@ init_optimization_passes (void)
NEXT_PASS (pass_rename_ssa_copies);
NEXT_PASS (pass_ccp);
NEXT_PASS (pass_forwprop);
NEXT_PASS (pass_update_address_taken);
NEXT_PASS (pass_simple_dse);
NEXT_PASS (pass_sra_early);
NEXT_PASS (pass_copy_prop);
NEXT_PASS (pass_merge_phi);
NEXT_PASS (pass_dce);
NEXT_PASS (pass_update_address_taken);
NEXT_PASS (pass_simple_dse);
NEXT_PASS (pass_tail_recursion);
NEXT_PASS (pass_profile);
NEXT_PASS (pass_release_ssa_names);

2
gcc/tree-pass.h
View file

@ -306,6 +306,7 @@ extern struct tree_opt_pass pass_forwprop;
extern struct tree_opt_pass pass_phiprop;
extern struct tree_opt_pass pass_tree_ifcombine;
extern struct tree_opt_pass pass_dse;
extern struct tree_opt_pass pass_simple_dse;
extern struct tree_opt_pass pass_nrv;
extern struct tree_opt_pass pass_mark_used_blocks;
extern struct tree_opt_pass pass_rename_ssa_copies;
@ -445,6 +446,7 @@ extern struct tree_opt_pass pass_early_inline;
extern struct tree_opt_pass pass_inline_parameters;
extern struct tree_opt_pass pass_apply_inline;
extern struct tree_opt_pass pass_all_early_optimizations;
extern struct tree_opt_pass pass_update_address_taken;
/* The root of the compilation pass tree, once constructed. */
extern struct tree_opt_pass *all_passes, *all_ipa_passes, *all_lowering_passes;

134
gcc/tree-ssa-dse.c
View file

@ -918,3 +918,137 @@ struct tree_opt_pass pass_dse = {
| TODO_verify_ssa, /* todo_flags_finish */
0 /* letter */
};
/* A very simple dead store pass eliminating write only local variables.
The pass does not require alias information and thus can be run before
inlining to quickly eliminate artifacts of some common C++ constructs. */
static unsigned int
execute_simple_dse (void)
{
block_stmt_iterator bsi;
basic_block bb;
bitmap variables_loaded = BITMAP_ALLOC (NULL);
unsigned int todo = 0;
/* Collect into VARIABLES LOADED all variables that are read in function
body. */
FOR_EACH_BB (bb)
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
if (LOADED_SYMS (bsi_stmt (bsi)))
bitmap_ior_into (variables_loaded,
LOADED_SYMS (bsi_stmt (bsi)));
/* Look for statements writting into the write only variables.
And try to remove them. */
FOR_EACH_BB (bb)
for (bsi = bsi_start (bb); !bsi_end_p (bsi);)
{
tree stmt = bsi_stmt (bsi), op;
bool removed = false;
ssa_op_iter iter;
if (STORED_SYMS (stmt) && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
&& TREE_CODE (stmt) != RETURN_EXPR
&& !bitmap_intersect_p (STORED_SYMS (stmt), variables_loaded))
{
unsigned int i;
bitmap_iterator bi;
bool dead = true;
/* See if STMT only stores to write-only variables and
verify that there are no volatile operands. tree-ssa-operands
sets has_volatile_ops flag for all statements involving
reads and writes when aliases are not built to prevent passes
from removing them as dead. The flag thus has no use for us
and we need to look into all operands. */
EXECUTE_IF_SET_IN_BITMAP (STORED_SYMS (stmt), 0, i, bi)
{
tree var = referenced_var_lookup (i);
if (TREE_ADDRESSABLE (var)
|| is_global_var (var)
|| TREE_THIS_VOLATILE (var))
dead = false;
}
if (dead && LOADED_SYMS (stmt))
EXECUTE_IF_SET_IN_BITMAP (LOADED_SYMS (stmt), 0, i, bi)
if (TREE_THIS_VOLATILE (referenced_var_lookup (i)))
dead = false;
if (dead)
FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_OPERANDS)
if (TREE_THIS_VOLATILE (op))
dead = false;
/* Look for possible occurence var = indirect_ref (...) where
indirect_ref itself is volatile. */
if (dead && TREE_THIS_VOLATILE (GIMPLE_STMT_OPERAND (stmt, 1)))
dead = false;
if (dead)
{
tree call = get_call_expr_in (stmt);
/* When LHS of var = call (); is dead, simplify it into
call (); saving one operand. */
if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
&& call
&& TREE_SIDE_EFFECTS (call))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Deleted LHS of call: ");
print_generic_stmt (dump_file, stmt, TDF_SLIM);
fprintf (dump_file, "\n");
}
push_stmt_changes (bsi_stmt_ptr (bsi));
TREE_BLOCK (call) = TREE_BLOCK (stmt);
bsi_replace (&bsi, call, false);
maybe_clean_or_replace_eh_stmt (stmt, call);
mark_symbols_for_renaming (call);
pop_stmt_changes (bsi_stmt_ptr (bsi));
}
else
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Deleted dead store '");
print_generic_expr (dump_file, stmt, dump_flags);
fprintf (dump_file, "'\n");
}
removed = true;
bsi_remove (&bsi, true);
todo |= TODO_cleanup_cfg;
}
todo |= TODO_remove_unused_locals | TODO_ggc_collect;
}
}
if (!removed)
bsi_next (&bsi);
}
BITMAP_FREE (variables_loaded);
return todo;
}
struct tree_opt_pass pass_simple_dse =
{
"sdse", /* name */
NULL, /* gate */
execute_simple_dse, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
0, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_dump_func, /* todo_flags_finish */
0 /* letter */
};

96
gcc/tree-ssa.c
View file

@ -1378,3 +1378,99 @@ struct tree_opt_pass pass_late_warn_uninitialized =
0, /* todo_flags_finish */
0 /* letter */
};
/* Compute TREE_ADDRESSABLE for local variables. */
static unsigned int
execute_update_addresses_taken (void)
{
tree var;
referenced_var_iterator rvi;
block_stmt_iterator bsi;
basic_block bb;
bitmap addresses_taken = BITMAP_ALLOC (NULL);
bitmap vars_updated = BITMAP_ALLOC (NULL);
bool update_vops;
tree phi;
/* Collect into ADDRESSES_TAKEN all variables whose address is taken within
the function body. */
FOR_EACH_BB (bb)
{
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
stmt_ann_t s_ann = stmt_ann (bsi_stmt (bsi));
if (s_ann->addresses_taken)
bitmap_ior_into (addresses_taken, s_ann->addresses_taken);
}
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
{
unsigned i, phi_num_args = PHI_NUM_ARGS (phi);
for (i = 0; i < phi_num_args; i++)
{
tree op = PHI_ARG_DEF (phi, i), var;
if (TREE_CODE (op) == ADDR_EXPR
&& (var = get_base_address (TREE_OPERAND (op, 0))) != NULL_TREE
&& DECL_P (var))
bitmap_set_bit (addresses_taken, DECL_UID (var));
}
}
}
/* When possible, clear ADDRESSABLE bit and mark variable for conversion into
SSA. */
FOR_EACH_REFERENCED_VAR (var, rvi)
if (!is_global_var (var)
&& TREE_CODE (var) != RESULT_DECL
&& TREE_ADDRESSABLE (var)
&& !bitmap_bit_p (addresses_taken, DECL_UID (var)))
{
TREE_ADDRESSABLE (var) = 0;
if (is_gimple_reg (var))
mark_sym_for_renaming (var);
update_vops = true;
bitmap_set_bit (vars_updated, DECL_UID (var));
if (dump_file)
{
fprintf (dump_file, "No longer having address taken ");
print_generic_expr (dump_file, var, 0);
fprintf (dump_file, "\n");
}
}
/* Operand caches needs to be recomputed for operands referencing the updated
variables. */
if (update_vops)
FOR_EACH_BB (bb)
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
if ((LOADED_SYMS (stmt)
&& bitmap_intersect_p (LOADED_SYMS (stmt), vars_updated))
|| (STORED_SYMS (stmt)
&& bitmap_intersect_p (STORED_SYMS (stmt), vars_updated)))
update_stmt (stmt);
}
BITMAP_FREE (addresses_taken);
BITMAP_FREE (vars_updated);
return 0;
}
struct tree_opt_pass pass_update_address_taken =
{
"addressables", /* name */
NULL, /* gate */
execute_update_addresses_taken, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
0, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_update_ssa, /* todo_flags_finish */
0 /* letter */
};