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cfgloop.h (fix_loop_placement, [...]): Declare.

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* cfgloop.h (fix_loop_placement, can_duplicate_loop_p,
	duplicate_loop_to_header_edge, loopify, remove_path, split_loop_bb):
	Declare.
	(DLTHE_FLAG_UPDATE_FREQ): New.
	* cfgloopmanip.c (duplicate_loop, duplicate_subloops, copy_loops_to,
	loop_redirect_edge, loop_delete_branch_edge, copy_bbs, remove_bbs,
	rpe_enum_p, find_branch, alp_enum_p, add_loop, fix_loop_placements,
	fix_bb_placement, fix_bb_placements, place_new_loop,
	scale_loop_frequencies, scale_bbs_frequencies, record_exit_edges):
	New static functions.
	(fix_loop_placement, can_duplicate_loop_p,
	duplicate_loop_to_header_edge, loopify, remove_path, split_loop_bb):
	New functions.

	* cfgloop.h (loop_optimizer_init, loop_optimizer_finalize,
	unswitch_loops): Declare.
	* loop-init.c: New file.
	* loop-unswitch.c: New file.
	* Makefile.in (loop-init.o, loop-unswitch.o): New.
	* params.def (PARAM_MAX_UNSWITCH_INSNS, PARAM_MAX_UNSWITCH_LEVEL): New.
	* toplev.c (DFI_loop2): New dump.
	(flag_unswitch_loops): New.
	(lang_independent_options): Add it.
	(rest_of_compilation): Call new loop optimizer.
	(parse_options_and_default_flags): Turn flag_unswitch_loops on with -O3.

From-SVN: r62578
This commit is contained in:
Zdenek Dvorak 2003-02-08 15:29:00 +01:00 committed by Zdenek Dvorak
parent 3bd03194ff
commit 617b465c7f
8 changed files with 1810 additions and 8 deletions
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28
gcc/ChangeLog
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@ -1,3 +1,31 @@
2003-02-08 Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz>
* cfgloop.h (fix_loop_placement, can_duplicate_loop_p,
duplicate_loop_to_header_edge, loopify, remove_path, split_loop_bb):
Declare.
(DLTHE_FLAG_UPDATE_FREQ): New.
* cfgloopmanip.c (duplicate_loop, duplicate_subloops, copy_loops_to,
loop_redirect_edge, loop_delete_branch_edge, copy_bbs, remove_bbs,
rpe_enum_p, find_branch, alp_enum_p, add_loop, fix_loop_placements,
fix_bb_placement, fix_bb_placements, place_new_loop,
scale_loop_frequencies, scale_bbs_frequencies, record_exit_edges):
New static functions.
(fix_loop_placement, can_duplicate_loop_p,
duplicate_loop_to_header_edge, loopify, remove_path, split_loop_bb):
New functions.
* cfgloop.h (loop_optimizer_init, loop_optimizer_finalize,
unswitch_loops): Declare.
* loop-init.c: New file.
* loop-unswitch.c: New file.
* Makefile.in (loop-init.o, loop-unswitch.o): New.
* params.def (PARAM_MAX_UNSWITCH_INSNS, PARAM_MAX_UNSWITCH_LEVEL): New.
* toplev.c (DFI_loop2): New dump.
(flag_unswitch_loops): New.
(lang_independent_options): Add it.
(rest_of_compilation): Call new loop optimizer.
(parse_options_and_default_flags): Turn flag_unswitch_loops on with -O3.
2003-02-08 Kazu Hirata <kazu@cs.umass.edu>
* config/h8300/clzsi2.c: New.

8
gcc/Makefile.in
View File

@ -768,7 +768,7 @@ C_OBJS = c-parse.o c-lang.o c-pretty-print.o $(C_AND_OBJC_OBJS)
OBJS = alias.o bb-reorder.o bitmap.o builtins.o caller-save.o calls.o \
cfg.o cfganal.o cfgbuild.o cfgcleanup.o cfglayout.o cfgloop.o \
cfgloopanal.o cfgloopmanip.o \
cfgloopanal.o cfgloopmanip.o loop-init.o loop-unswitch.o \
cfgrtl.o combine.o conflict.o convert.o cse.o cselib.o dbxout.o \
debug.o df.o diagnostic.o doloop.o dominance.o \
dwarf2asm.o dwarf2out.o dwarfout.o emit-rtl.o except.o explow.o \
@ -1600,6 +1600,12 @@ cfgloopanal.o : cfgloopanal.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) \
$(BASIC_BLOCK_H) hard-reg-set.h cfgloop.h $(EXPR_H) coretypes.h $(TM_H)
cfgloopmanip.o : cfgloopmanip.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) \
$(BASIC_BLOCK_H) hard-reg-set.h cfgloop.h cfglayout.h output.h coretypes.h $(TM_H)
loop-init.o : loop-init.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) gcov-io.h \
gcov-iov.h $(BASIC_BLOCK_H) hard-reg-set.h cfgloop.h cfglayout.h profile.h \
coretypes.h $(TM_H)
loop-unswitch.o : loop-unswitch.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TM_H) \
$(BASIC_BLOCK_H) hard-reg-set.h cfgloop.h cfglayout.h params.h \
output.h $(EXPR_H) coretypes.h $(TM_H)
dominance.o : dominance.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
hard-reg-set.h $(BASIC_BLOCK_H) et-forest.h
et-forest.o : et-forest.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) et-forest.h alloc-pool.h

25
gcc/cfgloop.h
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@ -293,6 +293,7 @@ extern void cancel_loop PARAMS ((struct loops *, struct loop *));
extern void cancel_loop_tree PARAMS ((struct loops *, struct loop *));
extern basic_block loop_split_edge_with PARAMS ((edge, rtx, struct loops *));
extern int fix_loop_placement PARAMS ((struct loop *));
enum
{
@ -312,3 +313,27 @@ extern rtx count_loop_iterations PARAMS ((struct loop_desc *, rtx, rtx));
extern bool just_once_each_iteration_p PARAMS ((struct loops *,struct loop *,
basic_block));
extern unsigned expected_loop_iterations PARAMS ((const struct loop *));
/* Loop manipulation. */
extern bool can_duplicate_loop_p PARAMS ((struct loop *loop));
#define DLTHE_FLAG_UPDATE_FREQ 1 /* Update frequencies in
duplicate_loop_to_header_edge. */
extern int duplicate_loop_to_header_edge PARAMS ((struct loop *, edge,
struct loops *, unsigned,
sbitmap, edge, edge *,
unsigned *, int));
extern struct loop *loopify PARAMS ((struct loops *, edge,
edge, basic_block));
extern bool remove_path PARAMS ((struct loops *, edge));
extern edge split_loop_bb PARAMS ((struct loops *, basic_block,
rtx));
/* Loop optimizer initialization. */
extern struct loops *loop_optimizer_init PARAMS ((FILE *));
extern void loop_optimizer_finalize PARAMS ((struct loops *, FILE *));
/* Optimization passes. */
extern void unswitch_loops PARAMS ((struct loops *));

1178
gcc/cfgloopmanip.c
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File diff suppressed because it is too large Load Diff

116
gcc/loop-init.c Normal file
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@ -0,0 +1,116 @@
/* Loop optimizer initialization routines.
Copyright (C) 2002, 2003 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 "rtl.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
#include "gcov-io.h"
#include "profile.h"
/* Initialize loop optimizer. */
struct loops *
loop_optimizer_init (dumpfile)
FILE *dumpfile;
{
struct loops *loops = xcalloc (1, sizeof (struct loops));
edge e;
/* Avoid annoying special cases of edges going to exit
block. */
for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
if ((e->flags & EDGE_FALLTHRU) && e->src->succ->succ_next)
split_edge (e);
/* Find the loops. */
if (flow_loops_find (loops, LOOP_TREE) <= 1)
{
/* No loops. */
flow_loops_free (loops);
free (loops);
return NULL;
}
/* Not going to update these. */
free (loops->cfg.rc_order);
loops->cfg.rc_order = NULL;
free (loops->cfg.dfs_order);
loops->cfg.dfs_order = NULL;
/* Initialize structures for layout changes. */
cfg_layout_initialize (loops);
/* Create pre-headers. */
create_preheaders (loops, CP_SIMPLE_PREHEADERS | CP_INSIDE_CFGLAYOUT);
/* Force all latches to have only single successor. */
force_single_succ_latches (loops);
/* Mark irreducible loops. */
mark_irreducible_loops (loops);
/* Dump loops. */
flow_loops_dump (loops, dumpfile, NULL, 1);
#ifdef ENABLE_CHECKING
verify_dominators (loops->cfg.dom);
verify_loop_structure (loops);
#endif
return loops;
}
/* Finalize loop optimizer. */
void
loop_optimizer_finalize (loops, dumpfile)
struct loops *loops;
FILE *dumpfile;
{
basic_block bb;
/* Finalize layout changes. */
/* Make chain. */
FOR_EACH_BB (bb)
if (bb->next_bb != EXIT_BLOCK_PTR)
RBI (bb)->next = bb->next_bb;
/* Another dump. */
flow_loops_dump (loops, dumpfile, NULL, 1);
/* Clean up. */
flow_loops_free (loops);
free (loops);
/* Finalize changes. */
cfg_layout_finalize ();
/* Checking. */
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
}

412
gcc/loop-unswitch.c Normal file
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@ -0,0 +1,412 @@
/* Loop unswitching for GNU compiler.
Copyright (C) 2002 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 "rtl.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
#include "params.h"
#include "output.h"
#include "expr.h"
/* This pass moves constant conditions out of loops, duplicating the loop
in progres, i.e. this code:
while (loop_cond)
{
A;
if (cond)
branch1;
else
branch2;
B;
if (cond)
branch3;
C;
}
where nothing inside the loop alters cond is transformed
into
if (cond)
{
while (loop_cond)
{
A;
branch1;
B;
branch3;
C;
}
}
else
{
while (loop_cond)
{
A;
branch2;
B;
C;
}
}
Duplicating the loop might lead to code growth exponential in number of
branches inside loop, so we limit the number of unswitchings performed
in a single loop to PARAM_MAX_UNSWITCH_LEVEL. We only perform the
transformation on innermost loops, as the benefit of doing it on loops
containing subloops would not be very large compared to complications
with handling this case. */
static struct loop *unswitch_loop PARAMS ((struct loops *,
struct loop *, basic_block));
static void unswitch_single_loop PARAMS ((struct loops *, struct loop *,
rtx, int));
static bool may_unswitch_on_p PARAMS ((struct loops *, basic_block,
struct loop *, basic_block *));
static rtx reversed_condition PARAMS ((rtx));
/* Main entry point. Perform loop unswitching on all suitable LOOPS. */
void
unswitch_loops (loops)
struct loops *loops;
{
int i, num;
struct loop *loop;
/* 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;
unswitch_single_loop (loops, loop, NULL_RTX, 0);
#ifdef ENABLE_CHECKING
verify_dominators (loops->cfg.dom);
verify_loop_structure (loops);
#endif
}
}
/* Checks whether we can unswitch LOOP on condition at end of BB -- one of its
basic blocks (for what it means see comments below). List of basic blocks
inside LOOP is provided in BODY to save time. */
static bool
may_unswitch_on_p (loops, bb, loop, body)
struct loops *loops;
basic_block bb;
struct loop *loop;
basic_block *body;
{
rtx test;
unsigned i;
/* BB must end in a simple conditional jump. */
if (!bb->succ || !bb->succ->succ_next || bb->succ->succ_next->succ_next)
return false;
if (!any_condjump_p (bb->end))
return false;
/* With branches inside loop. */
if (!flow_bb_inside_loop_p (loop, bb->succ->dest)
|| !flow_bb_inside_loop_p (loop, bb->succ->succ_next->dest))
return false;
/* It must be executed just once each iteration (because otherwise we
are unable to update dominator/irreducible loop information correctly). */
if (!just_once_each_iteration_p (loops, loop, bb))
return false;
/* Condition must be invariant. We use just a stupid test of invariantness
of the condition: all used regs must not be modified inside loop body. */
test = get_condition (bb->end, NULL);
if (!test)
return false;
for (i = 0; i < loop->num_nodes; i++)
if (modified_between_p (test, body[i]->head, NEXT_INSN (body[i]->end)))
return false;
return true;
}
/* Reverses CONDition; returns NULL if we cannot. */
static rtx
reversed_condition (cond)
rtx cond;
{
enum rtx_code reversed;
reversed = reversed_comparison_code (cond, NULL);
if (reversed == UNKNOWN)
return NULL_RTX;
else
return gen_rtx_fmt_ee (reversed,
GET_MODE (cond), XEXP (cond, 0),
XEXP (cond, 1));
}
/* Unswitch single LOOP. COND_CHECKED holds list of conditions we already
unswitched on and are therefore known to be true in this LOOP. NUM is
number of unswitchings done; do not allow it to grow too much, it is too
easy to create example on that the code would grow exponentially. */
static void
unswitch_single_loop (loops, loop, cond_checked, num)
struct loops *loops;
struct loop *loop;
rtx cond_checked;
int num;
{
basic_block *bbs, bb;
struct loop *nloop;
unsigned i;
int true_first;
rtx cond, rcond, conds, rconds, acond, split_before;
int always_true;
int always_false;
int repeat;
edge e;
/* Do not unswitch too much. */
if (num > PARAM_VALUE (PARAM_MAX_UNSWITCH_LEVEL))
{
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Not unswitching anymore, hit max level\n");
return;
}
/* Only unswitch innermost loops. */
if (loop->inner)
{
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Not unswitching, not innermost loop\n");
return;
}
/* We must be able to duplicate loop body. */
if (!can_duplicate_loop_p (loop))
{
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Not unswitching, can't duplicate loop\n");
return;
}
/* The loop should not be too large, to limit code growth. */
if (num_loop_insns (loop) > PARAM_VALUE (PARAM_MAX_UNSWITCH_INSNS))
{
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Not unswitching, loop too big\n");
return;
}
/* Do not unswitch in cold areas. */
if (!maybe_hot_bb_p (loop->header))
{
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Not unswitching, not hot area\n");
return;
}
/* Nor if the loop usually does not roll. */
if (expected_loop_iterations (loop) < 1)
{
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Not unswitching, loop iterations < 1\n");
return;
}
do
{
repeat = 0;
/* Find a bb to unswitch on. */
bbs = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
if (may_unswitch_on_p (loops, bbs[i], loop, bbs))
break;
if (i == loop->num_nodes)
{
free (bbs);
return;
}
if (!(cond = get_condition (bbs[i]->end, &split_before)))
abort ();
rcond = reversed_condition (cond);
/* Check whether the result can be predicted. */
always_true = 0;
always_false = 0;
for (acond = cond_checked; acond; acond = XEXP (acond, 1))
{
if (rtx_equal_p (cond, XEXP (acond, 0)))
{
always_true = 1;
break;
}
if (rtx_equal_p (rcond, XEXP (acond, 0)))
{
always_false = 1;
break;
}
}
if (always_true)
{
/* Remove false path. */
for (e = bbs[i]->succ; !(e->flags & EDGE_FALLTHRU); e = e->succ_next);
remove_path (loops, e);
free (bbs);
repeat = 1;
}
else if (always_false)
{
/* Remove true path. */
for (e = bbs[i]->succ; e->flags & EDGE_FALLTHRU; e = e->succ_next);
remove_path (loops, e);
free (bbs);
repeat = 1;
}
} while (repeat);
/* We found the condition we can unswitch on. */
conds = alloc_EXPR_LIST (0, cond, cond_checked);
if (rcond)
rconds = alloc_EXPR_LIST (0, rcond, cond_checked);
else
rconds = cond_checked;
/* Separate condition in a single basic block. */
bb = split_loop_bb (loops, bbs[i], PREV_INSN (split_before))->dest;
free (bbs);
true_first = !(bb->succ->flags & EDGE_FALLTHRU);
if (rtl_dump_file)
fprintf (rtl_dump_file, ";; Unswitching loop\n");
/* Unswitch the loop on this condition. */
nloop = unswitch_loop (loops, loop, bb);
if (!nloop)
abort ();
/* Invoke itself on modified loops. */
unswitch_single_loop (loops, nloop, true_first ? conds : rconds, num + 1);
unswitch_single_loop (loops, loop, true_first ? rconds : conds, num + 1);
free_EXPR_LIST_node (conds);
if (rcond)
free_EXPR_LIST_node (rconds);
}
/* Unswitch a LOOP w.r. to given basic block UNSWITCH_ON. We only support
unswitching of innermost loops. UNSWITCH_ON must be executed in every
iteration, i.e. it must dominate LOOP latch, and should only contain code
for the condition we unswitch on. Returns NULL if impossible, new
loop otherwise. */
static struct loop *
unswitch_loop (loops, loop, unswitch_on)
struct loops *loops;
struct loop *loop;
basic_block unswitch_on;
{
edge entry, e, latch_edge;
basic_block switch_bb, unswitch_on_alt, src;
struct loop *nloop;
sbitmap zero_bitmap;
int irred_flag;
/* Some sanity checking. */
if (!flow_bb_inside_loop_p (loop, unswitch_on))
abort ();
if (!unswitch_on->succ || !unswitch_on->succ->succ_next ||
unswitch_on->succ->succ_next->succ_next)
abort ();
if (!just_once_each_iteration_p (loops, loop, unswitch_on))
abort ();
if (loop->inner)
abort ();
if (!flow_bb_inside_loop_p (loop, unswitch_on->succ->dest))
abort ();
if (!flow_bb_inside_loop_p (loop, unswitch_on->succ->succ_next->dest))
abort ();
/* Will we be able to perform redirection? */
if (!any_condjump_p (unswitch_on->end))
return NULL;
if (!cfg_layout_can_duplicate_bb_p (unswitch_on))
return NULL;
entry = loop_preheader_edge (loop);
/* Make a copy. */
src = entry->src;
irred_flag = src->flags & BB_IRREDUCIBLE_LOOP;
src->flags &= ~BB_IRREDUCIBLE_LOOP;
zero_bitmap = sbitmap_alloc (2);
sbitmap_zero (zero_bitmap);
if (!duplicate_loop_to_header_edge (loop, entry, loops, 1,
zero_bitmap, NULL, NULL, NULL, 0))
return NULL;
free (zero_bitmap);
src->flags |= irred_flag;
/* Record the block with condition we unswitch on. */
unswitch_on_alt = RBI (unswitch_on)->copy;
/* Make a copy of the block containing the condition; we will use
it as switch to decide which loop we want to use. */
switch_bb = cfg_layout_duplicate_bb (unswitch_on, NULL);
switch_bb->flags &= ~BB_IRREDUCIBLE_LOOP;
switch_bb->flags |= irred_flag;
add_to_dominance_info (loops->cfg.dom, switch_bb);
RBI (unswitch_on)->copy = unswitch_on_alt;
/* Loopify from the copy of LOOP body, constructing the new loop. */
for (latch_edge = RBI (loop->latch)->copy->succ;
latch_edge->dest != loop->header;
latch_edge = latch_edge->succ_next);
nloop = loopify (loops, latch_edge,
RBI (loop->header)->copy->pred, switch_bb);
/* Remove branches that are now unreachable in new loops. We rely on the
fact that cfg_layout_duplicate_bb reverses list of edges. */
for (e = unswitch_on->succ->succ_next->dest->pred; e; e = e->pred_next)
if (e->src != unswitch_on &&
!dominated_by_p (loops->cfg.dom, e->src, e->dest))
break;
remove_path (loops, unswitch_on->succ);
remove_path (loops, unswitch_on_alt->succ);
/* One of created loops do not have to be subloop of the outer loop now,
so fix its placement in loop datastructure. */
fix_loop_placement (loop);
fix_loop_placement (nloop);
return nloop;
}

11
gcc/params.def
View File

@ -151,6 +151,17 @@ DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
"The maximum number of instructions to consider to unroll in a loop",
100)
/* The maximum number of insns of an unswitched loop. */
DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
"max-unswitch-insns",
"The maximum number of insns of an unswitched loop",
50)
/* The maximum level of recursion in unswitch_single_loop. */
DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
"max-unswitch-level",
"The maximum number of unswitchings in a single loop",
3)
DEFPARAM(HOT_BB_COUNT_FRACTION,
"hot-bb-count-fraction",
"Select fraction of the maximal count of repetitions of basic block in \

40
gcc/toplev.c
View File

@ -239,6 +239,7 @@ enum dump_file_index
DFI_bp,
DFI_ce1,
DFI_tracer,
DFI_loop2,
DFI_cse2,
DFI_life,
DFI_combine,
@ -289,6 +290,7 @@ static struct dump_file_info dump_file[DFI_MAX] =
{ "bp", 'b', 1, 0, 0 },
{ "ce1", 'C', 1, 0, 0 },
{ "tracer", 'T', 1, 0, 0 },
{ "loop2", 'L', 1, 0, 0 },
{ "cse2", 't', 1, 0, 0 },
{ "life", 'f', 1, 0, 0 }, /* Yes, duplicate enable switch. */
{ "combine", 'c', 1, 0, 0 },
@ -519,6 +521,9 @@ int flag_unroll_loops;
int flag_unroll_all_loops;
/* Nonzero enables loop unswitching. */
int flag_unswitch_loops;
/* Nonzero enables prefetch optimizations for arrays in loops. */
int flag_prefetch_loop_arrays;
@ -997,6 +1002,8 @@ static const lang_independent_options f_options[] =
N_("Perform loop unrolling when iteration count is known") },
{"unroll-all-loops", &flag_unroll_all_loops, 1,
N_("Perform loop unrolling for all loops") },
{"unswitch-loops", &flag_unswitch_loops, 1,
N_("Perform loop unswitching") },
{"prefetch-loop-arrays", &flag_prefetch_loop_arrays, 1,
N_("Generate prefetch instructions, if available, for arrays in loops") },
{"move-all-movables", &flag_move_all_movables, 1,
@ -3057,6 +3064,38 @@ rest_of_compilation (decl)
timevar_pop (TV_TRACER);
}
/* Perform loop optimalizations. It might be better to do them a bit
sooner, but we want the profile feedback to work more efficiently. */
if (optimize > 0
&& flag_unswitch_loops)
{
struct loops *loops;
timevar_push (TV_LOOP);
open_dump_file (DFI_loop2, decl);
if (rtl_dump_file)
dump_flow_info (rtl_dump_file);
loops = loop_optimizer_init (rtl_dump_file);
if (loops)
{
/* The optimalizations: */
if (flag_unswitch_loops)
unswitch_loops (loops);
loop_optimizer_finalize (loops, rtl_dump_file);
}
cleanup_cfg (CLEANUP_EXPENSIVE);
delete_trivially_dead_insns (insns, max_reg_num ());
reg_scan (insns, max_reg_num (), 0);
if (rtl_dump_file)
dump_flow_info (rtl_dump_file);
close_dump_file (DFI_loop2, print_rtl_with_bb, get_insns ());
timevar_pop (TV_LOOP);
ggc_collect ();
}
if (flag_rerun_cse_after_loop)
{
timevar_push (TV_CSE2);
@ -4884,6 +4923,7 @@ parse_options_and_default_flags (argc, argv)
{
flag_inline_functions = 1;
flag_rename_registers = 1;
flag_unswitch_loops = 1;
}
if (optimize < 2 || optimize_size)