8sa1-gcc/gcc/tree-ssa-loop-unswitch.c
Andrew MacLeod f430bae872 lambda-code.c (lambda_loopnest_to_gcc_loopnest): Use update_stmt.
2005-04-05  Andrew MacLeod  <amacleod@redhat.com>

	* lambda-code.c (lambda_loopnest_to_gcc_loopnest): Use update_stmt.
	Use immediate use iterator.
	(stmt_is_bumper_for_loop): Use immediate use iterator.
	* predict.c (strip_builtin_expect): Use update_stmt.
	* tree-cfg.c (update_modified_stmts): New. Call update_stmt_if_modified
	on all elements of a STATEMENT_LIST.
	(bsi_insert_before, bsi_insert_after): Call update_modified_stmts.
	(bsi_remove): Remove imm_use links and mark the stmt as modified.
	(bsi_replace): Mark stmt as modified and the update it.
	* tree-complex.c (update_complex_assignment): Call mark_stmt_modified.
	(expand_complex_libcal): Call update_stmt.
	(expand_complex_comparison): Call mark_stmt_modified.
	(expand_complex_operations_1): Call update_stmt_if_modified.
	(expand_vector_operations_1): Call mark_stmt_modified.
	* tree-dfa.c (compute_immediate_uses, free_df_for_stmt, free_df,
	compute_immediate_uses_for_phi, compute_immediate_uses_for_stmt,
	add_immediate_use, redirect_immediate_use,
	redirect_immediate_uses, dump_immediate_uses, debug_immediate_uses,
	dump_immediate_uses_for, debug_immediate_uses_for): Delete.
	(mark_new_vars_to_rename): Call update_stmt.
	* tree-dump.c (dump_option_value_in): Add "stmtaddr".
	* tree-flow-inline.h (modify_stmt): Rename to mark_stmt_modified.
	Ignore PHI nodes.
	(unmodify_stmt): Delete.
	(update_stmt): New.  Force an update of a stmt.
	(update_stmt_if_modified): update a stmt if it is out of date.
	(get_stmt_operands): Verify stmt is NOT modified.
	(stmt_modified_p): Update comment.
	(delink_imm_use): Remove a use node from its immuse list.
	(link_imm_use_to_list): Link a use node to a specific list.
	(link_imm_use): Link a node to the correct list.
	(set_ssa_use_from_ptr): Set a use node to a specific value, and insert
	it in the correct list, if appropriate.
	(link_imm_use_stmt): Link a use node, and set the stmt pointer.
	(relink_imm_use): Link a use node in place of another node in a list.
	(relink_imm_use_stmt): LInk a node in place of another node, and set
	the stmt pointer.
	(end_safe_imm_use_traverse): New.  Terminate a safe immuse iterator.
	(end_safe_imm_use_p): New.  Check for the end of a safe immuse iterator.
	(first_safe_imm_use): New.  Initialize a safe immuse iterator.
	(next_safe_imm_use): New.  Proceed to next safe immuse iterator value.
	(end_readonly_imm_use_p): New.  Check for end of a fast immuse iterator.
	(first_readonly_imm_use): New.  Initialize a fast immuse iterator.
	(next_readonly_imm_use): New.  Get the next fast immuse iterator value.
	(has_zero_uses): New.  Return true if there are no uses of a var.
	(has_single_use): New.  Return true if there is only a single use of a
	variable.
	(single_imm_use): New.  Return the simgle immediate use.
	(num_imm_uses): New.  Return the number of immediate uses.
	(get_v_must_def_ops): Use is now a pointer.
	(use_operand_p, get_v_may_def_op_ptr, get_vuse_op_ptr,
	get_v_must_def_kill_ptr, get_phi_arg_def_ptr): Return the address of
	the use node.
	(get_immediate_uses, num_immediate_uses, immediate_use): Delete.
	(delink_stmt_imm_use): Delink all immuses from a stmt.
	(phi_arg_index_from_use): New.  Return a phi arg index for a use.
	* tree-flow.h (struct dataflow_d): Delete.
	(immediate_use_iterator_d): New.  Immediate use iterator struct.
	(FOR_EACH_IMM_USE_FAST): New.  Macro for read only immuse iteration.
	(FOR_EACH_IMM_USE_SAFE): New.  Macro for write-safe immuse iteration.
	(BREAK_FROM_SAFE_IMM_USE): New.  Macro for earlyu exit from write-safe
	iteration.
	(struct stmt_ann_d): Remove dataflow_t from struct.
	* tree-if-conv.c (tree_if_conversion).  Don't call free_df.
	(if_convertible_phi_p): Use FAST immuse iterator.
	(if_convertible_loop_p): Don't call compute_immediate_uses.
	(replace_phi_with_cond_modify_expr): Call update_stmt.
	* tree-into-ssa.c (mark_def_sites, ssa_mark_def_sites): Call
	update_stmt_if_modified.
	(rewrite_all_into_ssa): Initialize ssa operands.
	* tree-loop-linear.c (linear_transform_loops): Don't call free_df or
	compute_immediate_uses.
	* tree-optimize.c (execute_todo): Call verify_ssa whenever the
	ssa_property is available.
	(execute_one_pass):  Change parameters passed to execute_todo.
	* tree-outof-ssa.c (rewrite_trees): Don't call modify_stmt.
	(remove_ssa_form): Call fini_ssa_operands.
	(insert_backedge_copies): Delete call to modify_stmt.
	* tree-phinodes.c (make_phi_node): Initialize use nodes.
	(release_phi_node): Delink any use nodes before releasing.
	(resize_phi_node): Relink any use nodes.
	(remove_phi_arg_num): Delink the use node.
	(remove_phi_node): Release the ssa_name AFTER releasing the phi node.
	(remove_all_phi_nodes_for): Release phi node first.
	* tree-pretty-print.c (dump_generic_node): Print stmt address.
	* tree-sra.c (mark_all_v_defs): Call update_stmt_if_modified.
	(scalarize_use, scalarize_copy): Call update_stmt.
	* tree-ssa-alias.c (compute_may_aliases): Update all modified stmts.
	(compute_points_to_and_addr_escape): Call mark_stmt_modified.
	* tree-ssa-cpp.c (need_imm_uses_for): Delete.
	(ccp_initialize): Remove call to compute_immediate_uses.
	(substitute_and_fold, execute_fold_all_builtins): Call update_stmt.
	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Update all modified
	stmts.
	(simplify_cond_and_lookup_avail_expr): Call mark_stmt_modified.
	(simplify_switch_and_lookup_avail_expr): Call mark_stmt_modified.
	(eliminate_redundant_computations): Call mark_stmt_modified.
	(cprop_operand): Call mark_stmt_modified.
	(optimize_stmt): Call update_stmt_if_modified and mark_stmt_modified.
	* tree-ssa-dse.c (fix_phi_uses, fix_stmt_v_may_defs): Delete.
	(dse_optimize_stmt): Use new immuse interface.
	(tree_ssa_dse): Remove calls to compute_immediate_uses and free_df.
	* tree-ssa-forwprop.c (need_imm_uses_for): Delete.
	(substitute_single_use_vars): Use new immuse interface.
	(tree_ssa_forward_propagate_single_use_vars): Remove calls to free_df
	and compute_immediate_uses.
	* tree-ssa-loop-im.c (single_reachable_address): Use new immuse
	interface.
	(rewrite_mem_refs): Call update_stmt.
	(determine_lsm): Remove call to compute_imm_uses and free_df.
	* tree-ssa-loop-ivcanon.c (create_canonical_iv): Call update_stmt.
	(try_unroll_loop_completely): Call update_stmt.
	* tree-ssa-loop-ivopts.c (rewrite_address_base): Call update_stmt.
	(rewrite_use_compare): Call update_stmt.
	(compute_phi_arg_on_exit): Insert each stmt before trying to process.
	(rewrite_use) : Call update_stmt.
	* tree-ssa-loop-manip.c (verify_loop_closed_ssa): Add arg to call.
	* tree-ssa-loop-unswitch.c (tree_unswitch_single_loop): Call
	update_stmt.
	* tree-ssa-operands.c (NULL_USE_OPERAND_P): Remove declaration.
	(allocate_use_optype, allocate_vuse_optype): Adjust allocation size.
	(free_uses, free_vuses, free_v_may_defs, free_v_must_defs): Delink
	use nodes.
	(initialize_vuse_operand): New.  Initialize a vuse operand.
	(initialize_v_may_def_operand): New.  Initialize a maydef operand.
	(initialize_v_must_def_operand): New.  Initialize a mustdef operand.
	(finalize_ssa_defs): Use stmt parameter.
	(correct_use_link): Ensure a use node is in the correct list, and has
	the correct stmt pointer.
	(finalize_ssa_uses, finalize_ssa_v_may_defs, finalize_ssa_vuses,
	finalize_ssa_v_must_defs): Also initialize use nodes.
	(finalize_ssa_stmt_operands): Pass extra stmt operands.
	(build_ssa_operands): Seperate parsing from final operand construction.
	(parse_ssa_operands): New.  Parse entry point for operand building.
	(swap_tree_operands): New.  Swap 2 tree operands.
	(update_stmt_operands): Ranamed from get_stmt_operands.  Always builds
	operands.
	(get_expr_operands): Call swap_tree_operands when needed.
	(copy_virtual_operands): Use initialize routines for virtual use ops.
	(create_ssa_artficial_load_stmt): Add extra stmt parameter.
	(verify_abort): New.  Issue imm_use error.
	(verify_imm_links): New Verify imm_use links for a var.
	(dump_immediate_uses_for): New.  Dump imm_uses for a var to file.
	(dump_immediate_uses): New.  Dump imm_uses for all vars to file.
	(debug_immediate_uses): New.  Dump imm_uses for all vars to stderr.
	(debug_immediate_uses_for): New.  Dump imm_uses for a var to stderr.
	* tree-ssa-operands.h (struct use_operand_ptr): Delete.
	(NULL_USE_OPERAND_P) Define.
	(use_optype_d, v_def_use_operand_type, vuse_optype_d): Add immediate
	use node.
	(struct vuse_operand_type): New struct.
	(SET_USE): Call set_ssa_use_from_ptr.
	(USE_STMT): Define.
	(PHI_ARG_INDEX_FROM_USE): Define.
	* tree-ssa-phiopt.c (replace_phi_edge_with_variable): Set the phi
	argument via SET_USE, not PHI_ARG_DEF_TREE.
	* tree-ssa-pre.c (eliminate): Call update_stmt.
	* tree-ssa-propagate.c (cfg_blocks_get): Use imm_use iterators.  Don't
	call free_df.
	* tree-ssa-sink.c (all_immediate_uses_same_place): Use imm_use iterator.
	(nearest_common_dominator_of_uses): Use imm_use iterator.
	(statement_sink_location): Use imm_use iterator and interface.
	(execute_sink_code): Don't call compute_immediate_uses or free-df.
	* tree-ssa-threadupdate.c (create_edge_and_update_destination_phis): Use
	PHI_ARG_DEF, not PHI_ARG_DEF_TREE.
	* tree-ssa.c (verify_use, verify_phi_args): Verify some imm_use info.
	(verify_ssa): Ensure no stmt is marked modify after optimization pass
	if new parameter is true.
	(init_tree_ssa): Don't initialize operand cache here.
	(delete_tree_ssa): Don't destroy operand cache here.
	(propagate_into_addr): Pass in a use pointer, return true if anything
	was changed.
	(replace_immediate_uses): Use imm_use iterator, call update_stmt.
	(check_phi_redundancy): Use imm_use iterator.
	(kill_redundant_phi_nodes): Don't call compute_immediate_uses or
	free_df.
	* tree-ssanames.c (make_ssa_name): Initialize imm_use node.
	(release_ssa_name): Delink node and all elements in its imm_use list.
	* tree-tailcall.c (adjust_return_value): Call update_stmt.
	* tree-vect-analyze.c (vect_stmt_relevant_p): Use imm_use iterator.
	* tree-vectorizer.c (need_imm_uses_for): Delete.
	(vectorize_loops): Dont call compute_immediate_uses or free_df.
	* tree.h (struct ssa_imm_use_d): Define.
	(SSA_NAME_IMM_USE_NODE): Define.
	(struct tree_ssa_name): Add imm_use node.
	(PHI_DF): Delete.
	(PHI_ARG_IMM_USE_NODE): Define.
	(struct phi_arg_d): Add imm_use node.
	(struct tree_phi_node): Remove struct dataflow_d element.
	(TDF_STMTADDR): Define.

From-SVN: r97648
2005-04-05 19:05:20 +00:00

289 lines
7.1 KiB
C

/* Loop unswitching.
Copyright (C) 2004, 2005 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 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, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
#include "diagnostic.h"
#include "tree-flow.h"
#include "tree-dump.h"
#include "timevar.h"
#include "cfgloop.h"
#include "domwalk.h"
#include "params.h"
#include "tree-pass.h"
/* This file implements the loop unswitching, i.e. transformation of loops like
while (A)
{
if (inv)
B;
X;
if (!inv)
C;
}
where inv is the loop invariant, into
if (inv)
{
while (A)
{
B;
X;
}
}
else
{
while (A)
{
X;
C;
}
}
Inv is considered invariant iff the values it compares are both invariant;
tree-ssa-loop-im.c ensures that all the suitable conditions are in this
shape. */
static struct loop *tree_unswitch_loop (struct loops *, struct loop *, basic_block,
tree);
static bool tree_unswitch_single_loop (struct loops *, struct loop *, int);
static tree tree_may_unswitch_on (basic_block, struct loop *);
/* Main entry point. Perform loop unswitching on all suitable LOOPS. */
void
tree_ssa_unswitch_loops (struct loops *loops)
{
int i, num;
struct loop *loop;
bool changed = false;
/* Go through inner loops (only original ones). */
num = loops->num;
for (i = 1; i < num; i++)
{
/* Removed loop? */
loop = loops->parray[i];
if (!loop)
continue;
if (loop->inner)
continue;
changed |= tree_unswitch_single_loop (loops, loop, 0);
#ifdef ENABLE_CHECKING
verify_dominators (CDI_DOMINATORS);
verify_loop_structure (loops);
#endif
}
if (changed)
cleanup_tree_cfg_loop ();
}
/* Checks whether we can unswitch LOOP on condition at end of BB -- one of its
basic blocks (for what it means see comments below). */
static tree
tree_may_unswitch_on (basic_block bb, struct loop *loop)
{
tree stmt, def, cond;
basic_block def_bb;
use_optype uses;
unsigned i;
/* BB must end in a simple conditional jump. */
stmt = last_stmt (bb);
if (!stmt || TREE_CODE (stmt) != COND_EXPR)
return NULL_TREE;
/* Condition must be invariant. */
get_stmt_operands (stmt);
uses = STMT_USE_OPS (stmt);
for (i = 0; i < NUM_USES (uses); i++)
{
def = SSA_NAME_DEF_STMT (USE_OP (uses, i));
def_bb = bb_for_stmt (def);
if (def_bb
&& flow_bb_inside_loop_p (loop, def_bb))
return NULL_TREE;
}
cond = COND_EXPR_COND (stmt);
/* To keep the things simple, we do not directly remove the conditions,
but just replace tests with 0/1. Prevent the infinite loop where we
would unswitch again on such a condition. */
if (integer_zerop (cond) || integer_nonzerop (cond))
return NULL_TREE;
return cond;
}
/* Simplifies COND using checks in front of the entry of the LOOP. Just very
simplish (sufficient to prevent us from duplicating loop in unswitching
unnecessarily). */
static tree
simplify_using_entry_checks (struct loop *loop, tree cond)
{
edge e = loop_preheader_edge (loop);
tree stmt;
while (1)
{
stmt = last_stmt (e->src);
if (stmt
&& TREE_CODE (stmt) == COND_EXPR
&& operand_equal_p (COND_EXPR_COND (stmt), cond, 0))
return (e->flags & EDGE_TRUE_VALUE
? boolean_true_node
: boolean_false_node);
if (!single_pred_p (e->src))
return cond;
e = single_pred_edge (e->src);
if (e->src == ENTRY_BLOCK_PTR)
return cond;
}
}
/* Unswitch single LOOP. NUM is number of unswitchings done; we do not allow
it to grow too much, it is too easy to create example on that the code would
grow exponentially. */
static bool
tree_unswitch_single_loop (struct loops *loops, struct loop *loop, int num)
{
basic_block *bbs;
struct loop *nloop;
unsigned i;
tree cond = NULL_TREE, stmt;
bool changed = false;
/* Do not unswitch too much. */
if (num > PARAM_VALUE (PARAM_MAX_UNSWITCH_LEVEL))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ";; Not unswitching anymore, hit max level\n");
return false;
}
/* Only unswitch innermost loops. */
if (loop->inner)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ";; Not unswitching, not innermost loop\n");
return false;
}
/* The loop should not be too large, to limit code growth. */
if (tree_num_loop_insns (loop)
> (unsigned) PARAM_VALUE (PARAM_MAX_UNSWITCH_INSNS))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ";; Not unswitching, loop too big\n");
return false;
}
i = 0;
bbs = get_loop_body (loop);
while (1)
{
/* Find a bb to unswitch on. */
for (; i < loop->num_nodes; i++)
if ((cond = tree_may_unswitch_on (bbs[i], loop)))
break;
if (i == loop->num_nodes)
{
free (bbs);
return changed;
}
cond = simplify_using_entry_checks (loop, cond);
stmt = last_stmt (bbs[i]);
if (integer_nonzerop (cond))
{
/* Remove false path. */
COND_EXPR_COND (stmt) = boolean_true_node;
changed = true;
}
else if (integer_zerop (cond))
{
/* Remove true path. */
COND_EXPR_COND (stmt) = boolean_false_node;
changed = true;
}
else
break;
update_stmt (stmt);
i++;
}
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ";; Unswitching loop\n");
/* Unswitch the loop on this condition. */
nloop = tree_unswitch_loop (loops, loop, bbs[i], cond);
if (!nloop)
return changed;
/* Invoke itself on modified loops. */
tree_unswitch_single_loop (loops, nloop, num + 1);
tree_unswitch_single_loop (loops, loop, num + 1);
return true;
}
/* Unswitch a LOOP w.r. to given basic block UNSWITCH_ON. We only support
unswitching of innermost loops. COND is the condition determining which
loop is entered -- the new loop is entered if COND is true. Returns NULL
if impossible, new loop otherwise. */
static struct loop *
tree_unswitch_loop (struct loops *loops, struct loop *loop,
basic_block unswitch_on, tree cond)
{
basic_block condition_bb;
/* Some sanity checking. */
gcc_assert (flow_bb_inside_loop_p (loop, unswitch_on));
gcc_assert (EDGE_COUNT (unswitch_on->succs) == 2);
gcc_assert (loop->inner == NULL);
return loop_version (loops, loop, unshare_expr (cond),
&condition_bb);
}