/* Loop unrolling and peeling.
- Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
This file is part of GCC.
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. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
#include "config.h"
#include "system.h"
#include "tm.h"
#include "rtl.h"
#include "hard-reg-set.h"
+#include "obstack.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
#include "params.h"
#include "output.h"
#include "expr.h"
+#include "hashtab.h"
+#include "recog.h"
/* This pass performs loop unrolling and peeling. We only perform these
optimizations on innermost loops (with single exception) because
showed that this choice may affect performance in order of several %.
*/
-static void decide_unrolling_and_peeling (struct loops *, int);
-static void peel_loops_completely (struct loops *, int);
-static void decide_peel_simple (struct loops *, struct loop *, int);
-static void decide_peel_once_rolling (struct loops *, struct loop *, int);
-static void decide_peel_completely (struct loops *, struct loop *, int);
-static void decide_unroll_stupid (struct loops *, struct loop *, int);
-static void decide_unroll_constant_iterations (struct loops *,
- struct loop *, int);
-static void decide_unroll_runtime_iterations (struct loops *, struct loop *,
- int);
-static void peel_loop_simple (struct loops *, struct loop *);
-static void peel_loop_completely (struct loops *, struct loop *);
-static void unroll_loop_stupid (struct loops *, struct loop *);
-static void unroll_loop_constant_iterations (struct loops *, struct loop *);
-static void unroll_loop_runtime_iterations (struct loops *, struct loop *);
+/* Information about induction variables to split. */
+
+struct iv_to_split
+{
+ rtx insn; /* The insn in that the induction variable occurs. */
+ rtx base_var; /* The variable on that the values in the further
+ iterations are based. */
+ rtx step; /* Step of the induction variable. */
+ unsigned n_loc;
+ unsigned loc[3]; /* Location where the definition of the induction
+ variable occurs in the insn. For example if
+ N_LOC is 2, the expression is located at
+ XEXP (XEXP (single_set, loc[0]), loc[1]). */
+};
+
+/* Information about accumulators to expand. */
+
+struct var_to_expand
+{
+ rtx insn; /* The insn in that the variable expansion occurs. */
+ rtx reg; /* The accumulator which is expanded. */
+ VEC(rtx,heap) *var_expansions; /* The copies of the accumulator which is expanded. */
+ enum rtx_code op; /* The type of the accumulation - addition, subtraction
+ or multiplication. */
+ int expansion_count; /* Count the number of expansions generated so far. */
+ int reuse_expansion; /* The expansion we intend to reuse to expand
+ the accumulator. If REUSE_EXPANSION is 0 reuse
+ the original accumulator. Else use
+ var_expansions[REUSE_EXPANSION - 1]. */
+};
+
+/* Information about optimization applied in
+ the unrolled loop. */
+
+struct opt_info
+{
+ htab_t insns_to_split; /* A hashtable of insns to split. */
+ htab_t insns_with_var_to_expand; /* A hashtable of insns with accumulators
+ to expand. */
+ unsigned first_new_block; /* The first basic block that was
+ duplicated. */
+ basic_block loop_exit; /* The loop exit basic block. */
+ basic_block loop_preheader; /* The loop preheader basic block. */
+};
+
+static void decide_unrolling_and_peeling (int);
+static void peel_loops_completely (int);
+static void decide_peel_simple (struct loop *, int);
+static void decide_peel_once_rolling (struct loop *, int);
+static void decide_peel_completely (struct loop *, int);
+static void decide_unroll_stupid (struct loop *, int);
+static void decide_unroll_constant_iterations (struct loop *, int);
+static void decide_unroll_runtime_iterations (struct loop *, int);
+static void peel_loop_simple (struct loop *);
+static void peel_loop_completely (struct loop *);
+static void unroll_loop_stupid (struct loop *);
+static void unroll_loop_constant_iterations (struct loop *);
+static void unroll_loop_runtime_iterations (struct loop *);
+static struct opt_info *analyze_insns_in_loop (struct loop *);
+static void opt_info_start_duplication (struct opt_info *);
+static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool);
+static void free_opt_info (struct opt_info *);
+static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx);
+static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx);
+static struct iv_to_split *analyze_iv_to_split_insn (rtx);
+static void expand_var_during_unrolling (struct var_to_expand *, rtx);
+static int insert_var_expansion_initialization (void **, void *);
+static int combine_var_copies_in_loop_exit (void **, void *);
+static int release_var_copies (void **, void *);
+static rtx get_expansion (struct var_to_expand *);
/* Unroll and/or peel (depending on FLAGS) LOOPS. */
void
-unroll_and_peel_loops (struct loops *loops, int flags)
+unroll_and_peel_loops (int flags)
{
- struct loop *loop, *next;
- int check;
+ struct loop *loop;
+ bool check;
+ loop_iterator li;
/* First perform complete loop peeling (it is almost surely a win,
and affects parameters for further decision a lot). */
- peel_loops_completely (loops, flags);
+ peel_loops_completely (flags);
/* Now decide rest of unrolling and peeling. */
- decide_unrolling_and_peeling (loops, flags);
-
- loop = loops->tree_root;
- while (loop->inner)
- loop = loop->inner;
+ decide_unrolling_and_peeling (flags);
/* Scan the loops, inner ones first. */
- while (loop != loops->tree_root)
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- if (loop->next)
- {
- next = loop->next;
- while (next->inner)
- next = next->inner;
- }
- else
- next = loop->outer;
-
- check = 1;
+ check = true;
/* And perform the appropriate transformations. */
switch (loop->lpt_decision.decision)
{
case LPT_PEEL_COMPLETELY:
/* Already done. */
- abort ();
+ gcc_unreachable ();
case LPT_PEEL_SIMPLE:
- peel_loop_simple (loops, loop);
+ peel_loop_simple (loop);
break;
case LPT_UNROLL_CONSTANT:
- unroll_loop_constant_iterations (loops, loop);
+ unroll_loop_constant_iterations (loop);
break;
case LPT_UNROLL_RUNTIME:
- unroll_loop_runtime_iterations (loops, loop);
+ unroll_loop_runtime_iterations (loop);
break;
case LPT_UNROLL_STUPID:
- unroll_loop_stupid (loops, loop);
+ unroll_loop_stupid (loop);
break;
case LPT_NONE:
- check = 0;
+ check = false;
break;
default:
- abort ();
+ gcc_unreachable ();
}
if (check)
{
#ifdef ENABLE_CHECKING
- verify_dominators (loops->cfg.dom);
- verify_loop_structure (loops);
+ verify_dominators (CDI_DOMINATORS);
+ verify_loop_structure ();
#endif
}
- loop = next;
}
+
+ iv_analysis_done ();
}
-/* Check whether to peel LOOPS (depending on FLAGS) completely and do so. */
-static void
-peel_loops_completely (struct loops *loops, int flags)
+/* Check whether exit of the LOOP is at the end of loop body. */
+
+static bool
+loop_exit_at_end_p (struct loop *loop)
{
- struct loop *loop, *next;
+ struct niter_desc *desc = get_simple_loop_desc (loop);
+ rtx insn;
- loop = loops->tree_root;
- while (loop->inner)
- loop = loop->inner;
+ if (desc->in_edge->dest != loop->latch)
+ return false;
- while (loop != loops->tree_root)
+ /* Check that the latch is empty. */
+ FOR_BB_INSNS (loop->latch, insn)
{
- if (loop->next)
- {
- next = loop->next;
- while (next->inner)
- next = next->inner;
- }
- else
- next = loop->outer;
+ if (INSN_P (insn))
+ return false;
+ }
+ return true;
+}
+
+/* Depending on FLAGS, check whether to peel loops completely and do so. */
+static void
+peel_loops_completely (int flags)
+{
+ struct loop *loop;
+ loop_iterator li;
+
+ /* Scan the loops, the inner ones first. */
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
+ {
loop->lpt_decision.decision = LPT_NONE;
- loop->has_desc = 0;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering loop %d for complete peeling\n",
+ if (dump_file)
+ fprintf (dump_file,
+ "\n;; *** Considering loop %d for complete peeling ***\n",
loop->num);
loop->ninsns = num_loop_insns (loop);
- decide_peel_once_rolling (loops, loop, flags);
+ decide_peel_once_rolling (loop, flags);
if (loop->lpt_decision.decision == LPT_NONE)
- decide_peel_completely (loops, loop, flags);
+ decide_peel_completely (loop, flags);
if (loop->lpt_decision.decision == LPT_PEEL_COMPLETELY)
{
- peel_loop_completely (loops, loop);
+ peel_loop_completely (loop);
#ifdef ENABLE_CHECKING
- verify_dominators (loops->cfg.dom);
- verify_loop_structure (loops);
+ verify_dominators (CDI_DOMINATORS);
+ verify_loop_structure ();
#endif
}
- loop = next;
}
}
-/* Decide whether unroll or peel LOOPS (depending on FLAGS) and how much. */
+/* Decide whether unroll or peel loops (depending on FLAGS) and how much. */
static void
-decide_unrolling_and_peeling (struct loops *loops, int flags)
+decide_unrolling_and_peeling (int flags)
{
- struct loop *loop = loops->tree_root, *next;
-
- while (loop->inner)
- loop = loop->inner;
+ struct loop *loop;
+ loop_iterator li;
/* Scan the loops, inner ones first. */
- while (loop != loops->tree_root)
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- if (loop->next)
- {
- next = loop->next;
- while (next->inner)
- next = next->inner;
- }
- else
- next = loop->outer;
-
loop->lpt_decision.decision = LPT_NONE;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering loop %d\n", loop->num);
+ if (dump_file)
+ fprintf (dump_file, "\n;; *** Considering loop %d ***\n", loop->num);
/* Do not peel cold areas. */
if (!maybe_hot_bb_p (loop->header))
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, cold area\n");
- loop = next;
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, cold area\n");
continue;
}
/* Can the loop be manipulated? */
if (!can_duplicate_loop_p (loop))
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file,
+ if (dump_file)
+ fprintf (dump_file,
";; Not considering loop, cannot duplicate\n");
- loop = next;
continue;
}
/* Skip non-innermost loops. */
if (loop->inner)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is not innermost\n");
- loop = next;
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is not innermost\n");
continue;
}
/* Try transformations one by one in decreasing order of
priority. */
- decide_unroll_constant_iterations (loops, loop, flags);
+ decide_unroll_constant_iterations (loop, flags);
if (loop->lpt_decision.decision == LPT_NONE)
- decide_unroll_runtime_iterations (loops, loop, flags);
+ decide_unroll_runtime_iterations (loop, flags);
if (loop->lpt_decision.decision == LPT_NONE)
- decide_unroll_stupid (loops, loop, flags);
+ decide_unroll_stupid (loop, flags);
if (loop->lpt_decision.decision == LPT_NONE)
- decide_peel_simple (loops, loop, flags);
-
- loop = next;
+ decide_peel_simple (loop, flags);
}
}
/* Decide whether the LOOP is once rolling and suitable for complete
peeling. */
static void
-decide_peel_once_rolling (struct loops *loops, struct loop *loop,
- int flags ATTRIBUTE_UNUSED)
+decide_peel_once_rolling (struct loop *loop, int flags ATTRIBUTE_UNUSED)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering peeling once rolling loop\n");
+ struct niter_desc *desc;
+
+ if (dump_file)
+ fprintf (dump_file, "\n;; Considering peeling once rolling loop\n");
/* Is the loop small enough? */
if ((unsigned) PARAM_VALUE (PARAM_MAX_ONCE_PEELED_INSNS) < loop->ninsns)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is too big\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is too big\n");
return;
}
/* Check for simple loops. */
- loop->simple = simple_loop_p (loops, loop, &loop->desc);
- loop->has_desc = 1;
+ desc = get_simple_loop_desc (loop);
/* Check number of iterations. */
- if (!loop->simple || !loop->desc.const_iter || loop->desc.niter != 0)
+ if (!desc->simple_p
+ || desc->assumptions
+ || desc->infinite
+ || !desc->const_iter
+ || desc->niter != 0)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Unable to prove that the loop rolls exactly once\n");
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Unable to prove that the loop rolls exactly once\n");
return;
}
/* Success. */
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Decided to peel exactly once rolling loop\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Decided to peel exactly once rolling loop\n");
loop->lpt_decision.decision = LPT_PEEL_COMPLETELY;
}
/* Decide whether the LOOP is suitable for complete peeling. */
static void
-decide_peel_completely (struct loops *loops, struct loop *loop,
- int flags ATTRIBUTE_UNUSED)
+decide_peel_completely (struct loop *loop, int flags ATTRIBUTE_UNUSED)
{
unsigned npeel;
+ struct niter_desc *desc;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering peeling completely\n");
+ if (dump_file)
+ fprintf (dump_file, "\n;; Considering peeling completely\n");
/* Skip non-innermost loops. */
if (loop->inner)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is not innermost\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is not innermost\n");
return;
}
/* Do not peel cold areas. */
if (!maybe_hot_bb_p (loop->header))
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, cold area\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, cold area\n");
return;
}
/* Can the loop be manipulated? */
if (!can_duplicate_loop_p (loop))
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file,
+ if (dump_file)
+ fprintf (dump_file,
";; Not considering loop, cannot duplicate\n");
return;
}
/* Is the loop small enough? */
if (!npeel)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is too big\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is too big\n");
return;
}
/* Check for simple loops. */
- if (!loop->has_desc)
- {
- loop->simple = simple_loop_p (loops, loop, &loop->desc);
- loop->has_desc = 1;
- }
+ desc = get_simple_loop_desc (loop);
/* Check number of iterations. */
- if (!loop->simple || !loop->desc.const_iter)
+ if (!desc->simple_p
+ || desc->assumptions
+ || !desc->const_iter
+ || desc->infinite)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Unable to prove that the loop iterates constant times\n");
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Unable to prove that the loop iterates constant times\n");
return;
}
- if (loop->desc.niter > npeel - 1)
+ if (desc->niter > npeel - 1)
{
- if (rtl_dump_file)
+ if (dump_file)
{
- fprintf (rtl_dump_file, ";; Not peeling loop completely, rolls too much (");
- fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC,(HOST_WIDEST_INT) loop->desc.niter);
- fprintf (rtl_dump_file, " iterations > %d [maximum peelings])\n", npeel);
+ fprintf (dump_file,
+ ";; Not peeling loop completely, rolls too much (");
+ fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC, desc->niter);
+ fprintf (dump_file, " iterations > %d [maximum peelings])\n", npeel);
}
return;
}
/* Success. */
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Decided to peel loop completely\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Decided to peel loop completely\n");
loop->lpt_decision.decision = LPT_PEEL_COMPLETELY;
}
body; i++;
*/
static void
-peel_loop_completely (struct loops *loops, struct loop *loop)
+peel_loop_completely (struct loop *loop)
{
sbitmap wont_exit;
unsigned HOST_WIDE_INT npeel;
- unsigned n_remove_edges, i;
- edge *remove_edges;
- struct loop_desc *desc = &loop->desc;
-
+ unsigned i;
+ VEC (edge, heap) *remove_edges;
+ edge ein;
+ struct niter_desc *desc = get_simple_loop_desc (loop);
+ struct opt_info *opt_info = NULL;
+
npeel = desc->niter;
if (npeel)
{
+ bool ok;
+
wont_exit = sbitmap_alloc (npeel + 1);
sbitmap_ones (wont_exit);
RESET_BIT (wont_exit, 0);
- if (desc->may_be_zero)
+ if (desc->noloop_assumptions)
RESET_BIT (wont_exit, 1);
- remove_edges = xcalloc (npeel, sizeof (edge));
- n_remove_edges = 0;
-
- if (!duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, npeel,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+ remove_edges = NULL;
+
+ if (flag_split_ivs_in_unroller)
+ opt_info = analyze_insns_in_loop (loop);
+
+ opt_info_start_duplication (opt_info);
+ ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
+ npeel,
+ wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ
+ | DLTHE_FLAG_COMPLETTE_PEEL
+ | (opt_info
+ ? DLTHE_RECORD_COPY_NUMBER : 0));
+ gcc_assert (ok);
free (wont_exit);
+
+ if (opt_info)
+ {
+ apply_opt_in_copies (opt_info, npeel, false, true);
+ free_opt_info (opt_info);
+ }
/* Remove the exit edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (loops, remove_edges[i]);
- free (remove_edges);
+ for (i = 0; VEC_iterate (edge, remove_edges, i, ein); i++)
+ remove_path (ein);
+ VEC_free (edge, heap, remove_edges);
}
+ ein = desc->in_edge;
+ free_simple_loop_desc (loop);
+
/* Now remove the unreachable part of the last iteration and cancel
the loop. */
- remove_path (loops, desc->in_edge);
+ remove_path (ein);
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Peeled loop completely, %d times\n", (int) npeel);
+ if (dump_file)
+ fprintf (dump_file, ";; Peeled loop completely, %d times\n", (int) npeel);
}
-/* Decide whether to unroll LOOP iterating constant number of times and how much. */
+/* Decide whether to unroll LOOP iterating constant number of times
+ and how much. */
+
static void
-decide_unroll_constant_iterations (struct loops *loops, struct loop *loop,
- int flags)
+decide_unroll_constant_iterations (struct loop *loop, int flags)
{
- unsigned nunroll, nunroll_by_av, best_copies, best_unroll = -1, n_copies, i;
+ unsigned nunroll, nunroll_by_av, best_copies, best_unroll = 0, n_copies, i;
+ struct niter_desc *desc;
if (!(flags & UAP_UNROLL))
{
return;
}
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering unrolling loop with constant number of iterations\n");
+ if (dump_file)
+ fprintf (dump_file,
+ "\n;; Considering unrolling loop with constant "
+ "number of iterations\n");
/* nunroll = total number of copies of the original loop body in
unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */
nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns;
- nunroll_by_av = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns;
+ nunroll_by_av
+ = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns;
if (nunroll > nunroll_by_av)
nunroll = nunroll_by_av;
if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES))
/* Skip big loops. */
if (nunroll <= 1)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is too big\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is too big\n");
return;
}
/* Check for simple loops. */
- if (!loop->has_desc)
- {
- loop->simple = simple_loop_p (loops, loop, &loop->desc);
- loop->has_desc = 1;
- }
+ desc = get_simple_loop_desc (loop);
/* Check number of iterations. */
- if (!loop->simple || !loop->desc.const_iter)
+ if (!desc->simple_p || !desc->const_iter || desc->assumptions)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Unable to prove that the loop iterates constant times\n");
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Unable to prove that the loop iterates constant times\n");
return;
}
/* Check whether the loop rolls enough to consider. */
- if (loop->desc.niter < 2 * nunroll)
+ if (desc->niter < 2 * nunroll)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not unrolling loop, doesn't roll\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n");
return;
}
best_copies = 2 * nunroll + 10;
i = 2 * nunroll + 2;
- if ((unsigned) i - 1 >= loop->desc.niter)
- i = loop->desc.niter - 2;
+ if (i - 1 >= desc->niter)
+ i = desc->niter - 2;
for (; i >= nunroll - 1; i--)
{
- unsigned exit_mod = loop->desc.niter % (i + 1);
+ unsigned exit_mod = desc->niter % (i + 1);
- if (loop->desc.postincr)
+ if (!loop_exit_at_end_p (loop))
n_copies = exit_mod + i + 1;
- else if (exit_mod != (unsigned) i || loop->desc.may_be_zero)
+ else if (exit_mod != (unsigned) i
+ || desc->noloop_assumptions != NULL_RTX)
n_copies = exit_mod + i + 2;
else
n_copies = i + 1;
}
}
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; max_unroll %d (%d copies, initial %d).\n",
+ if (dump_file)
+ fprintf (dump_file, ";; max_unroll %d (%d copies, initial %d).\n",
best_unroll + 1, best_copies, nunroll);
loop->lpt_decision.decision = LPT_UNROLL_CONSTANT;
loop->lpt_decision.times = best_unroll;
+
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Decided to unroll the constant times rolling loop, %d times.\n",
+ loop->lpt_decision.times);
}
/* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES + 1
}
*/
static void
-unroll_loop_constant_iterations (struct loops *loops, struct loop *loop)
+unroll_loop_constant_iterations (struct loop *loop)
{
unsigned HOST_WIDE_INT niter;
unsigned exit_mod;
sbitmap wont_exit;
- unsigned n_remove_edges, i;
- edge *remove_edges;
+ unsigned i;
+ VEC (edge, heap) *remove_edges;
+ edge e;
unsigned max_unroll = loop->lpt_decision.times;
- struct loop_desc *desc = &loop->desc;
-
+ struct niter_desc *desc = get_simple_loop_desc (loop);
+ bool exit_at_end = loop_exit_at_end_p (loop);
+ struct opt_info *opt_info = NULL;
+ bool ok;
+
niter = desc->niter;
- if (niter <= (unsigned) max_unroll + 1)
- abort (); /* Should not get here (such loop should be peeled instead). */
+ /* Should not get here (such loop should be peeled instead). */
+ gcc_assert (niter > max_unroll + 1);
exit_mod = niter % (max_unroll + 1);
wont_exit = sbitmap_alloc (max_unroll + 1);
sbitmap_ones (wont_exit);
- remove_edges = xcalloc (max_unroll + exit_mod + 1, sizeof (edge));
- n_remove_edges = 0;
-
- if (desc->postincr)
+ remove_edges = NULL;
+ if (flag_split_ivs_in_unroller
+ || flag_variable_expansion_in_unroller)
+ opt_info = analyze_insns_in_loop (loop);
+
+ if (!exit_at_end)
{
- /* Counter is incremented after the exit test; leave exit test
+ /* The exit is not at the end of the loop; leave exit test
in the first copy, so that the loops that start with test
of exit condition have continuous body after unrolling. */
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Condition on beginning of loop.\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Condition on beginning of loop.\n");
/* Peel exit_mod iterations. */
RESET_BIT (wont_exit, 0);
- if (desc->may_be_zero)
+ if (desc->noloop_assumptions)
RESET_BIT (wont_exit, 1);
- if (exit_mod
- && !duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, exit_mod,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+ if (exit_mod)
+ {
+ opt_info_start_duplication (opt_info);
+ ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
+ exit_mod,
+ wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ
+ | (opt_info && exit_mod > 1
+ ? DLTHE_RECORD_COPY_NUMBER
+ : 0));
+ gcc_assert (ok);
+
+ if (opt_info && exit_mod > 1)
+ apply_opt_in_copies (opt_info, exit_mod, false, false);
+
+ desc->noloop_assumptions = NULL_RTX;
+ desc->niter -= exit_mod;
+ desc->niter_max -= exit_mod;
+ }
SET_BIT (wont_exit, 1);
}
/* Leave exit test in last copy, for the same reason as above if
the loop tests the condition at the end of loop body. */
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Condition on end of loop.\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Condition on end of loop.\n");
/* We know that niter >= max_unroll + 2; so we do not need to care of
case when we would exit before reaching the loop. So just peel
- exit_mod + 1 iterations.
- */
- if (exit_mod != (unsigned) max_unroll || desc->may_be_zero)
+ exit_mod + 1 iterations. */
+ if (exit_mod != max_unroll
+ || desc->noloop_assumptions)
{
RESET_BIT (wont_exit, 0);
- if (desc->may_be_zero)
+ if (desc->noloop_assumptions)
RESET_BIT (wont_exit, 1);
-
- if (!duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, exit_mod + 1,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+
+ opt_info_start_duplication (opt_info);
+ ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
+ exit_mod + 1,
+ wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ
+ | (opt_info && exit_mod > 0
+ ? DLTHE_RECORD_COPY_NUMBER
+ : 0));
+ gcc_assert (ok);
+
+ if (opt_info && exit_mod > 0)
+ apply_opt_in_copies (opt_info, exit_mod + 1, false, false);
+
+ desc->niter -= exit_mod + 1;
+ desc->niter_max -= exit_mod + 1;
+ desc->noloop_assumptions = NULL_RTX;
SET_BIT (wont_exit, 0);
SET_BIT (wont_exit, 1);
}
/* Now unroll the loop. */
- if (!duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
- loops, max_unroll,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+
+ opt_info_start_duplication (opt_info);
+ ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
+ max_unroll,
+ wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ
+ | (opt_info
+ ? DLTHE_RECORD_COPY_NUMBER
+ : 0));
+ gcc_assert (ok);
+
+ if (opt_info)
+ {
+ apply_opt_in_copies (opt_info, max_unroll, true, true);
+ free_opt_info (opt_info);
+ }
free (wont_exit);
+ if (exit_at_end)
+ {
+ basic_block exit_block = get_bb_copy (desc->in_edge->src);
+ /* Find a new in and out edge; they are in the last copy we have made. */
+
+ if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest)
+ {
+ desc->out_edge = EDGE_SUCC (exit_block, 0);
+ desc->in_edge = EDGE_SUCC (exit_block, 1);
+ }
+ else
+ {
+ desc->out_edge = EDGE_SUCC (exit_block, 1);
+ desc->in_edge = EDGE_SUCC (exit_block, 0);
+ }
+ }
+
+ desc->niter /= max_unroll + 1;
+ desc->niter_max /= max_unroll + 1;
+ desc->niter_expr = GEN_INT (desc->niter);
+
/* Remove the edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (loops, remove_edges[i]);
- free (remove_edges);
+ for (i = 0; VEC_iterate (edge, remove_edges, i, e); i++)
+ remove_path (e);
+ VEC_free (edge, heap, remove_edges);
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Unrolled loop %d times, constant # of iterations %i insns\n",max_unroll, num_loop_insns (loop));
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Unrolled loop %d times, constant # of iterations %i insns\n",
+ max_unroll, num_loop_insns (loop));
}
/* Decide whether to unroll LOOP iterating runtime computable number of times
and how much. */
static void
-decide_unroll_runtime_iterations (struct loops *loops, struct loop *loop,
- int flags)
+decide_unroll_runtime_iterations (struct loop *loop, int flags)
{
unsigned nunroll, nunroll_by_av, i;
+ struct niter_desc *desc;
if (!(flags & UAP_UNROLL))
{
return;
}
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering unrolling loop with runtime computable number of iterations\n");
+ if (dump_file)
+ fprintf (dump_file,
+ "\n;; Considering unrolling loop with runtime "
+ "computable number of iterations\n");
/* nunroll = total number of copies of the original loop body in
unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */
/* Skip big loops. */
if (nunroll <= 1)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is too big\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is too big\n");
return;
}
/* Check for simple loops. */
- if (!loop->has_desc)
- {
- loop->simple = simple_loop_p (loops, loop, &loop->desc);
- loop->has_desc = 1;
- }
+ desc = get_simple_loop_desc (loop);
/* Check simpleness. */
- if (!loop->simple)
+ if (!desc->simple_p || desc->assumptions)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Unable to prove that the number of iterations can be counted in runtime\n");
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Unable to prove that the number of iterations "
+ "can be counted in runtime\n");
return;
}
- if (loop->desc.const_iter)
+ if (desc->const_iter)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Loop iterates constant times\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Loop iterates constant times\n");
return;
}
/* If we have profile feedback, check whether the loop rolls. */
if (loop->header->count && expected_loop_iterations (loop) < 2 * nunroll)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not unrolling loop, doesn't roll\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n");
return;
}
/* Success; now force nunroll to be power of 2, as we are unable to
cope with overflows in computation of number of iterations. */
- for (i = 1; 2 * i <= nunroll; i *= 2);
+ for (i = 1; 2 * i <= nunroll; i *= 2)
+ continue;
loop->lpt_decision.decision = LPT_UNROLL_RUNTIME;
loop->lpt_decision.times = i - 1;
+
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Decided to unroll the runtime computable "
+ "times rolling loop, %d times.\n",
+ loop->lpt_decision.times);
+}
+
+/* Splits edge E and inserts the sequence of instructions INSNS on it, and
+ returns the newly created block. If INSNS is NULL_RTX, nothing is changed
+ and NULL is returned instead. */
+
+basic_block
+split_edge_and_insert (edge e, rtx insns)
+{
+ basic_block bb;
+
+ if (!insns)
+ return NULL;
+ bb = split_edge (e);
+ emit_insn_after (insns, BB_END (bb));
+
+ /* ??? We used to assume that INSNS can contain control flow insns, and
+ that we had to try to find sub basic blocks in BB to maintain a valid
+ CFG. For this purpose we used to set the BB_SUPERBLOCK flag on BB
+ and call break_superblocks when going out of cfglayout mode. But it
+ turns out that this never happens; and that if it does ever happen,
+ the verify_flow_info call in loop_optimizer_finalize would fail.
+
+ There are two reasons why we expected we could have control flow insns
+ in INSNS. The first is when a comparison has to be done in parts, and
+ the second is when the number of iterations is computed for loops with
+ the number of iterations known at runtime. In both cases, test cases
+ to get control flow in INSNS appear to be impossible to construct:
+
+ * If do_compare_rtx_and_jump needs several branches to do comparison
+ in a mode that needs comparison by parts, we cannot analyze the
+ number of iterations of the loop, and we never get to unrolling it.
+
+ * The code in expand_divmod that was suspected to cause creation of
+ branching code seems to be only accessed for signed division. The
+ divisions used by # of iterations analysis are always unsigned.
+ Problems might arise on architectures that emits branching code
+ for some operations that may appear in the unroller (especially
+ for division), but we have no such architectures.
+
+ Considering all this, it was decided that we should for now assume
+ that INSNS can in theory contain control flow insns, but in practice
+ it never does. So we don't handle the theoretical case, and should
+ a real failure ever show up, we have a pretty good clue for how to
+ fix it. */
+
+ return bb;
}
/* Unroll LOOP for that we are able to count number of iterations in runtime
}
*/
static void
-unroll_loop_runtime_iterations (struct loops *loops, struct loop *loop)
+unroll_loop_runtime_iterations (struct loop *loop)
{
- rtx niter, init_code, branch_code, jump, label;
+ rtx old_niter, niter, init_code, branch_code, tmp;
unsigned i, j, p;
basic_block preheader, *body, *dom_bbs, swtch, ezc_swtch;
unsigned n_dom_bbs;
sbitmap wont_exit;
int may_exit_copy;
- unsigned n_peel, n_remove_edges;
- edge *remove_edges, e;
+ unsigned n_peel;
+ VEC (edge, heap) *remove_edges;
+ edge e;
bool extra_zero_check, last_may_exit;
unsigned max_unroll = loop->lpt_decision.times;
- struct loop_desc *desc = &loop->desc;
-
+ struct niter_desc *desc = get_simple_loop_desc (loop);
+ bool exit_at_end = loop_exit_at_end_p (loop);
+ struct opt_info *opt_info = NULL;
+ bool ok;
+
+ if (flag_split_ivs_in_unroller
+ || flag_variable_expansion_in_unroller)
+ opt_info = analyze_insns_in_loop (loop);
+
/* Remember blocks whose dominators will have to be updated. */
- dom_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ dom_bbs = XCNEWVEC (basic_block, n_basic_blocks);
n_dom_bbs = 0;
body = get_loop_body (loop);
unsigned nldom;
basic_block *ldom;
- nldom = get_dominated_by (loops->cfg.dom, body[i], &ldom);
+ nldom = get_dominated_by (CDI_DOMINATORS, body[i], &ldom);
for (j = 0; j < nldom; j++)
if (!flow_bb_inside_loop_p (loop, ldom[j]))
dom_bbs[n_dom_bbs++] = ldom[j];
}
free (body);
- if (desc->postincr)
+ if (!exit_at_end)
{
/* Leave exit in first copy (for explanation why see comment in
unroll_loop_constant_iterations). */
/* Get expression for number of iterations. */
start_sequence ();
- niter = count_loop_iterations (desc, NULL, NULL);
- if (!niter)
- abort ();
- niter = force_operand (niter, NULL);
+ old_niter = niter = gen_reg_rtx (desc->mode);
+ tmp = force_operand (copy_rtx (desc->niter_expr), niter);
+ if (tmp != niter)
+ emit_move_insn (niter, tmp);
/* Count modulo by ANDing it with max_unroll; we use the fact that
the number of unrollings is a power of two, and thus this is correct
even if there is overflow in the computation. */
- niter = expand_simple_binop (GET_MODE (desc->var), AND,
+ niter = expand_simple_binop (desc->mode, AND,
niter,
GEN_INT (max_unroll),
NULL_RTX, 0, OPTAB_LIB_WIDEN);
end_sequence ();
/* Precondition the loop. */
- loop_split_edge_with (loop_preheader_edge (loop), init_code, loops);
+ split_edge_and_insert (loop_preheader_edge (loop), init_code);
- remove_edges = xcalloc (max_unroll + n_peel + 1, sizeof (edge));
- n_remove_edges = 0;
+ remove_edges = NULL;
wont_exit = sbitmap_alloc (max_unroll + 2);
/* Peel the first copy of loop body (almost always we must leave exit test
here; the only exception is when we have extra zero check and the number
- of iterations is reliable (i.e. comes out of NE condition). Also record
- the place of (possible) extra zero check. */
+ of iterations is reliable. Also record the place of (possible) extra
+ zero check. */
sbitmap_zero (wont_exit);
- if (extra_zero_check && desc->cond == NE)
+ if (extra_zero_check
+ && !desc->noloop_assumptions)
SET_BIT (wont_exit, 1);
ezc_swtch = loop_preheader_edge (loop)->src;
- if (!duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, 1,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+ ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
+ 1, wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ);
+ gcc_assert (ok);
/* Record the place where switch will be built for preconditioning. */
- swtch = loop_split_edge_with (loop_preheader_edge (loop),
- NULL_RTX, loops);
+ swtch = split_edge (loop_preheader_edge (loop));
for (i = 0; i < n_peel; i++)
{
sbitmap_zero (wont_exit);
if (i != n_peel - 1 || !last_may_exit)
SET_BIT (wont_exit, 1);
- if (!duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, 1,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+ ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
+ 1, wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ);
+ gcc_assert (ok);
/* Create item for switch. */
j = n_peel - i - (extra_zero_check ? 0 : 1);
p = REG_BR_PROB_BASE / (i + 2);
- preheader = loop_split_edge_with (loop_preheader_edge (loop),
- NULL_RTX, loops);
- label = block_label (preheader);
- start_sequence ();
- do_compare_rtx_and_jump (copy_rtx (niter), GEN_INT (j), EQ, 0,
- GET_MODE (desc->var), NULL_RTX, NULL_RTX,
- label);
- jump = get_last_insn ();
- JUMP_LABEL (jump) = label;
- REG_NOTES (jump)
- = gen_rtx_EXPR_LIST (REG_BR_PROB,
- GEN_INT (p), REG_NOTES (jump));
-
- LABEL_NUSES (label)++;
- branch_code = get_insns ();
- end_sequence ();
-
- swtch = loop_split_edge_with (swtch->pred, branch_code, loops);
- set_immediate_dominator (loops->cfg.dom, preheader, swtch);
- swtch->succ->probability = REG_BR_PROB_BASE - p;
+ preheader = split_edge (loop_preheader_edge (loop));
+ branch_code = compare_and_jump_seq (copy_rtx (niter), GEN_INT (j), EQ,
+ block_label (preheader), p,
+ NULL_RTX);
+
+ /* We rely on the fact that the compare and jump cannot be optimized out,
+ and hence the cfg we create is correct. */
+ gcc_assert (branch_code != NULL_RTX);
+
+ swtch = split_edge_and_insert (single_pred_edge (swtch), branch_code);
+ set_immediate_dominator (CDI_DOMINATORS, preheader, swtch);
+ single_pred_edge (swtch)->probability = REG_BR_PROB_BASE - p;
e = make_edge (swtch, preheader,
- swtch->succ->flags & EDGE_IRREDUCIBLE_LOOP);
+ single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP);
e->probability = p;
}
/* Add branch for zero iterations. */
p = REG_BR_PROB_BASE / (max_unroll + 1);
swtch = ezc_swtch;
- preheader = loop_split_edge_with (loop_preheader_edge (loop),
- NULL_RTX, loops);
- label = block_label (preheader);
- start_sequence ();
- do_compare_rtx_and_jump (copy_rtx (niter), const0_rtx, EQ, 0,
- GET_MODE (desc->var), NULL_RTX, NULL_RTX,
- label);
- jump = get_last_insn ();
- JUMP_LABEL (jump) = label;
- REG_NOTES (jump)
- = gen_rtx_EXPR_LIST (REG_BR_PROB,
- GEN_INT (p), REG_NOTES (jump));
-
- LABEL_NUSES (label)++;
- branch_code = get_insns ();
- end_sequence ();
-
- swtch = loop_split_edge_with (swtch->succ, branch_code, loops);
- set_immediate_dominator (loops->cfg.dom, preheader, swtch);
- swtch->succ->probability = REG_BR_PROB_BASE - p;
+ preheader = split_edge (loop_preheader_edge (loop));
+ branch_code = compare_and_jump_seq (copy_rtx (niter), const0_rtx, EQ,
+ block_label (preheader), p,
+ NULL_RTX);
+ gcc_assert (branch_code != NULL_RTX);
+
+ swtch = split_edge_and_insert (single_succ_edge (swtch), branch_code);
+ set_immediate_dominator (CDI_DOMINATORS, preheader, swtch);
+ single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p;
e = make_edge (swtch, preheader,
- swtch->succ->flags & EDGE_IRREDUCIBLE_LOOP);
+ single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP);
e->probability = p;
}
/* Recount dominators for outer blocks. */
- iterate_fix_dominators (loops->cfg.dom, dom_bbs, n_dom_bbs);
+ iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, n_dom_bbs);
/* And unroll loop. */
sbitmap_ones (wont_exit);
RESET_BIT (wont_exit, may_exit_copy);
-
- if (!duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
- loops, max_unroll,
- wont_exit, desc->out_edge, remove_edges, &n_remove_edges,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+ opt_info_start_duplication (opt_info);
+
+ ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
+ max_unroll,
+ wont_exit, desc->out_edge,
+ &remove_edges,
+ DLTHE_FLAG_UPDATE_FREQ
+ | (opt_info
+ ? DLTHE_RECORD_COPY_NUMBER
+ : 0));
+ gcc_assert (ok);
+
+ if (opt_info)
+ {
+ apply_opt_in_copies (opt_info, max_unroll, true, true);
+ free_opt_info (opt_info);
+ }
free (wont_exit);
+ if (exit_at_end)
+ {
+ basic_block exit_block = get_bb_copy (desc->in_edge->src);
+ /* Find a new in and out edge; they are in the last copy we have
+ made. */
+
+ if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest)
+ {
+ desc->out_edge = EDGE_SUCC (exit_block, 0);
+ desc->in_edge = EDGE_SUCC (exit_block, 1);
+ }
+ else
+ {
+ desc->out_edge = EDGE_SUCC (exit_block, 1);
+ desc->in_edge = EDGE_SUCC (exit_block, 0);
+ }
+ }
+
/* Remove the edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (loops, remove_edges[i]);
- free (remove_edges);
+ for (i = 0; VEC_iterate (edge, remove_edges, i, e); i++)
+ remove_path (e);
+ VEC_free (edge, heap, remove_edges);
+
+ /* We must be careful when updating the number of iterations due to
+ preconditioning and the fact that the value must be valid at entry
+ of the loop. After passing through the above code, we see that
+ the correct new number of iterations is this: */
+ gcc_assert (!desc->const_iter);
+ desc->niter_expr =
+ simplify_gen_binary (UDIV, desc->mode, old_niter,
+ GEN_INT (max_unroll + 1));
+ desc->niter_max /= max_unroll + 1;
+ if (exit_at_end)
+ {
+ desc->niter_expr =
+ simplify_gen_binary (MINUS, desc->mode, desc->niter_expr, const1_rtx);
+ desc->noloop_assumptions = NULL_RTX;
+ desc->niter_max--;
+ }
- if (rtl_dump_file)
- fprintf (rtl_dump_file,
- ";; Unrolled loop %d times, counting # of iterations in runtime, %i insns\n",
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Unrolled loop %d times, counting # of iterations "
+ "in runtime, %i insns\n",
max_unroll, num_loop_insns (loop));
+
+ if (dom_bbs)
+ free (dom_bbs);
}
/* Decide whether to simply peel LOOP and how much. */
static void
-decide_peel_simple (struct loops *loops, struct loop *loop, int flags)
+decide_peel_simple (struct loop *loop, int flags)
{
unsigned npeel;
+ struct niter_desc *desc;
if (!(flags & UAP_PEEL))
{
return;
}
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering simply peeling loop\n");
+ if (dump_file)
+ fprintf (dump_file, "\n;; Considering simply peeling loop\n");
/* npeel = number of iterations to peel. */
npeel = PARAM_VALUE (PARAM_MAX_PEELED_INSNS) / loop->ninsns;
/* Skip big loops. */
if (!npeel)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is too big\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is too big\n");
return;
}
/* Check for simple loops. */
- if (!loop->has_desc)
- {
- loop->simple = simple_loop_p (loops, loop, &loop->desc);
- loop->has_desc = 1;
- }
+ desc = get_simple_loop_desc (loop);
/* Check number of iterations. */
- if (loop->simple && loop->desc.const_iter)
+ if (desc->simple_p && !desc->assumptions && desc->const_iter)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Loop iterates constant times\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Loop iterates constant times\n");
return;
}
/* Do not simply peel loops with branches inside -- it increases number
of mispredicts. */
- if (loop->desc.n_branches > 1)
+ if (num_loop_branches (loop) > 1)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not peeling, contains branches\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not peeling, contains branches\n");
return;
}
unsigned niter = expected_loop_iterations (loop);
if (niter + 1 > npeel)
{
- if (rtl_dump_file)
+ if (dump_file)
{
- fprintf (rtl_dump_file, ";; Not peeling loop, rolls too much (");
- fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) (niter + 1));
- fprintf (rtl_dump_file, " iterations > %d [maximum peelings])\n", npeel);
+ fprintf (dump_file, ";; Not peeling loop, rolls too much (");
+ fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC,
+ (HOST_WIDEST_INT) (niter + 1));
+ fprintf (dump_file, " iterations > %d [maximum peelings])\n",
+ npeel);
}
return;
}
{
/* For now we have no good heuristics to decide whether loop peeling
will be effective, so disable it. */
- if (rtl_dump_file)
- fprintf (rtl_dump_file,
+ if (dump_file)
+ fprintf (dump_file,
";; Not peeling loop, no evidence it will be profitable\n");
return;
}
/* Success. */
loop->lpt_decision.decision = LPT_PEEL_SIMPLE;
loop->lpt_decision.times = npeel;
+
+ if (dump_file)
+ fprintf (dump_file, ";; Decided to simply peel the loop, %d times.\n",
+ loop->lpt_decision.times);
}
/* Peel a LOOP LOOP->LPT_DECISION.TIMES times. The transformation:
end: ;
*/
static void
-peel_loop_simple (struct loops *loops, struct loop *loop)
+peel_loop_simple (struct loop *loop)
{
sbitmap wont_exit;
unsigned npeel = loop->lpt_decision.times;
-
+ struct niter_desc *desc = get_simple_loop_desc (loop);
+ struct opt_info *opt_info = NULL;
+ bool ok;
+
+ if (flag_split_ivs_in_unroller && npeel > 1)
+ opt_info = analyze_insns_in_loop (loop);
+
wont_exit = sbitmap_alloc (npeel + 1);
sbitmap_zero (wont_exit);
-
- if (!duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, npeel, wont_exit, NULL, NULL, NULL,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+
+ opt_info_start_duplication (opt_info);
+
+ ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
+ npeel, wont_exit, NULL,
+ NULL, DLTHE_FLAG_UPDATE_FREQ
+ | (opt_info
+ ? DLTHE_RECORD_COPY_NUMBER
+ : 0));
+ gcc_assert (ok);
free (wont_exit);
+
+ if (opt_info)
+ {
+ apply_opt_in_copies (opt_info, npeel, false, false);
+ free_opt_info (opt_info);
+ }
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Peeling loop %d times\n", npeel);
+ if (desc->simple_p)
+ {
+ if (desc->const_iter)
+ {
+ desc->niter -= npeel;
+ desc->niter_expr = GEN_INT (desc->niter);
+ desc->noloop_assumptions = NULL_RTX;
+ }
+ else
+ {
+ /* We cannot just update niter_expr, as its value might be clobbered
+ inside loop. We could handle this by counting the number into
+ temporary just like we do in runtime unrolling, but it does not
+ seem worthwhile. */
+ free_simple_loop_desc (loop);
+ }
+ }
+ if (dump_file)
+ fprintf (dump_file, ";; Peeling loop %d times\n", npeel);
}
/* Decide whether to unroll LOOP stupidly and how much. */
static void
-decide_unroll_stupid (struct loops *loops, struct loop *loop, int flags)
+decide_unroll_stupid (struct loop *loop, int flags)
{
unsigned nunroll, nunroll_by_av, i;
+ struct niter_desc *desc;
if (!(flags & UAP_UNROLL_ALL))
{
return;
}
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Considering unrolling loop stupidly\n");
+ if (dump_file)
+ fprintf (dump_file, "\n;; Considering unrolling loop stupidly\n");
/* nunroll = total number of copies of the original loop body in
unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */
nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns;
- nunroll_by_av = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns;
+ nunroll_by_av
+ = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns;
if (nunroll > nunroll_by_av)
nunroll = nunroll_by_av;
if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES))
/* Skip big loops. */
if (nunroll <= 1)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not considering loop, is too big\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not considering loop, is too big\n");
return;
}
/* Check for simple loops. */
- if (!loop->has_desc)
- {
- loop->simple = simple_loop_p (loops, loop, &loop->desc);
- loop->has_desc = 1;
- }
+ desc = get_simple_loop_desc (loop);
/* Check simpleness. */
- if (loop->simple)
+ if (desc->simple_p && !desc->assumptions)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; The loop is simple\n");
+ if (dump_file)
+ fprintf (dump_file, ";; The loop is simple\n");
return;
}
/* Do not unroll loops with branches inside -- it increases number
of mispredicts. */
- if (loop->desc.n_branches > 1)
+ if (num_loop_branches (loop) > 1)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not unrolling, contains branches\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not unrolling, contains branches\n");
return;
}
/* If we have profile feedback, check whether the loop rolls. */
- if (loop->header->count && expected_loop_iterations (loop) < 2 * nunroll)
+ if (loop->header->count
+ && expected_loop_iterations (loop) < 2 * nunroll)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Not unrolling loop, doesn't roll\n");
+ if (dump_file)
+ fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n");
return;
}
/* Success. Now force nunroll to be power of 2, as it seems that this
improves results (partially because of better alignments, partially
because of some dark magic). */
- for (i = 1; 2 * i <= nunroll; i *= 2);
+ for (i = 1; 2 * i <= nunroll; i *= 2)
+ continue;
loop->lpt_decision.decision = LPT_UNROLL_STUPID;
loop->lpt_decision.times = i - 1;
+
+ if (dump_file)
+ fprintf (dump_file,
+ ";; Decided to unroll the loop stupidly, %d times.\n",
+ loop->lpt_decision.times);
}
/* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation:
}
*/
static void
-unroll_loop_stupid (struct loops *loops, struct loop *loop)
+unroll_loop_stupid (struct loop *loop)
{
sbitmap wont_exit;
unsigned nunroll = loop->lpt_decision.times;
-
+ struct niter_desc *desc = get_simple_loop_desc (loop);
+ struct opt_info *opt_info = NULL;
+ bool ok;
+
+ if (flag_split_ivs_in_unroller
+ || flag_variable_expansion_in_unroller)
+ opt_info = analyze_insns_in_loop (loop);
+
+
wont_exit = sbitmap_alloc (nunroll + 1);
sbitmap_zero (wont_exit);
-
- if (!duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
- loops, nunroll, wont_exit, NULL, NULL, NULL,
- DLTHE_FLAG_UPDATE_FREQ))
- abort ();
+ opt_info_start_duplication (opt_info);
+
+ ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
+ nunroll, wont_exit,
+ NULL, NULL,
+ DLTHE_FLAG_UPDATE_FREQ
+ | (opt_info
+ ? DLTHE_RECORD_COPY_NUMBER
+ : 0));
+ gcc_assert (ok);
+
+ if (opt_info)
+ {
+ apply_opt_in_copies (opt_info, nunroll, true, true);
+ free_opt_info (opt_info);
+ }
free (wont_exit);
- if (rtl_dump_file)
- fprintf (rtl_dump_file, ";; Unrolled loop %d times, %i insns\n",
+ if (desc->simple_p)
+ {
+ /* We indeed may get here provided that there are nontrivial assumptions
+ for a loop to be really simple. We could update the counts, but the
+ problem is that we are unable to decide which exit will be taken
+ (not really true in case the number of iterations is constant,
+ but noone will do anything with this information, so we do not
+ worry about it). */
+ desc->simple_p = false;
+ }
+
+ if (dump_file)
+ fprintf (dump_file, ";; Unrolled loop %d times, %i insns\n",
nunroll, num_loop_insns (loop));
}
+
+/* A hash function for information about insns to split. */
+
+static hashval_t
+si_info_hash (const void *ivts)
+{
+ return (hashval_t) INSN_UID (((struct iv_to_split *) ivts)->insn);
+}
+
+/* An equality functions for information about insns to split. */
+
+static int
+si_info_eq (const void *ivts1, const void *ivts2)
+{
+ const struct iv_to_split *i1 = ivts1;
+ const struct iv_to_split *i2 = ivts2;
+
+ return i1->insn == i2->insn;
+}
+
+/* Return a hash for VES, which is really a "var_to_expand *". */
+
+static hashval_t
+ve_info_hash (const void *ves)
+{
+ return (hashval_t) INSN_UID (((struct var_to_expand *) ves)->insn);
+}
+
+/* Return true if IVTS1 and IVTS2 (which are really both of type
+ "var_to_expand *") refer to the same instruction. */
+
+static int
+ve_info_eq (const void *ivts1, const void *ivts2)
+{
+ const struct var_to_expand *i1 = ivts1;
+ const struct var_to_expand *i2 = ivts2;
+
+ return i1->insn == i2->insn;
+}
+
+/* Returns true if REG is referenced in one insn in LOOP. */
+
+bool
+referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg)
+{
+ basic_block *body, bb;
+ unsigned i;
+ int count_ref = 0;
+ rtx insn;
+
+ body = get_loop_body (loop);
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ bb = body[i];
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ if (rtx_referenced_p (reg, insn))
+ count_ref++;
+ }
+ }
+ return (count_ref == 1);
+}
+
+/* Determine whether INSN contains an accumulator
+ which can be expanded into separate copies,
+ one for each copy of the LOOP body.
+
+ for (i = 0 ; i < n; i++)
+ sum += a[i];
+
+ ==>
+
+ sum += a[i]
+ ....
+ i = i+1;
+ sum1 += a[i]
+ ....
+ i = i+1
+ sum2 += a[i];
+ ....
+
+ Return NULL if INSN contains no opportunity for expansion of accumulator.
+ Otherwise, allocate a VAR_TO_EXPAND structure, fill it with the relevant
+ information and return a pointer to it.
+*/
+
+static struct var_to_expand *
+analyze_insn_to_expand_var (struct loop *loop, rtx insn)
+{
+ rtx set, dest, src, op1;
+ struct var_to_expand *ves;
+ enum machine_mode mode1, mode2;
+
+ set = single_set (insn);
+ if (!set)
+ return NULL;
+
+ dest = SET_DEST (set);
+ src = SET_SRC (set);
+
+ if (GET_CODE (src) != PLUS
+ && GET_CODE (src) != MINUS
+ && GET_CODE (src) != MULT)
+ return NULL;
+
+ /* Hmm, this is a bit paradoxical. We know that INSN is a valid insn
+ in MD. But if there is no optab to generate the insn, we can not
+ perform the variable expansion. This can happen if an MD provides
+ an insn but not a named pattern to generate it, for example to avoid
+ producing code that needs additional mode switches like for x87/mmx.
+
+ So we check have_insn_for which looks for an optab for the operation
+ in SRC. If it doesn't exist, we can't perform the expansion even
+ though INSN is valid. */
+ if (!have_insn_for (GET_CODE (src), GET_MODE (src)))
+ return NULL;
+
+ if (!XEXP (src, 0))
+ return NULL;
+
+ op1 = XEXP (src, 0);
+
+ if (!REG_P (dest)
+ && !(GET_CODE (dest) == SUBREG
+ && REG_P (SUBREG_REG (dest))))
+ return NULL;
+
+ if (!rtx_equal_p (dest, op1))
+ return NULL;
+
+ if (!referenced_in_one_insn_in_loop_p (loop, dest))
+ return NULL;
+
+ if (rtx_referenced_p (dest, XEXP (src, 1)))
+ return NULL;
+
+ mode1 = GET_MODE (dest);
+ mode2 = GET_MODE (XEXP (src, 1));
+ if ((FLOAT_MODE_P (mode1)
+ || FLOAT_MODE_P (mode2))
+ && !flag_unsafe_math_optimizations)
+ return NULL;
+
+ if (dump_file)
+ {
+ fprintf (dump_file,
+ "\n;; Expanding Accumulator ");
+ print_rtl (dump_file, dest);
+ fprintf (dump_file, "\n");
+ }
+
+ /* Record the accumulator to expand. */
+ ves = XNEW (struct var_to_expand);
+ ves->insn = insn;
+ ves->var_expansions = VEC_alloc (rtx, heap, 1);
+ ves->reg = copy_rtx (dest);
+ ves->op = GET_CODE (src);
+ ves->expansion_count = 0;
+ ves->reuse_expansion = 0;
+ return ves;
+}
+
+/* Determine whether there is an induction variable in INSN that
+ we would like to split during unrolling.
+
+ I.e. replace
+
+ i = i + 1;
+ ...
+ i = i + 1;
+ ...
+ i = i + 1;
+ ...
+
+ type chains by
+
+ i0 = i + 1
+ ...
+ i = i0 + 1
+ ...
+ i = i0 + 2
+ ...
+
+ Return NULL if INSN contains no interesting IVs. Otherwise, allocate
+ an IV_TO_SPLIT structure, fill it with the relevant information and return a
+ pointer to it. */
+
+static struct iv_to_split *
+analyze_iv_to_split_insn (rtx insn)
+{
+ rtx set, dest;
+ struct rtx_iv iv;
+ struct iv_to_split *ivts;
+ bool ok;
+
+ /* For now we just split the basic induction variables. Later this may be
+ extended for example by selecting also addresses of memory references. */
+ set = single_set (insn);
+ if (!set)
+ return NULL;
+
+ dest = SET_DEST (set);
+ if (!REG_P (dest))
+ return NULL;
+
+ if (!biv_p (insn, dest))
+ return NULL;
+
+ ok = iv_analyze_result (insn, dest, &iv);
+
+ /* This used to be an assert under the assumption that if biv_p returns
+ true that iv_analyze_result must also return true. However, that
+ assumption is not strictly correct as evidenced by pr25569.
+
+ Returning NULL when iv_analyze_result returns false is safe and
+ avoids the problems in pr25569 until the iv_analyze_* routines
+ can be fixed, which is apparently hard and time consuming
+ according to their author. */
+ if (! ok)
+ return NULL;
+
+ if (iv.step == const0_rtx
+ || iv.mode != iv.extend_mode)
+ return NULL;
+
+ /* Record the insn to split. */
+ ivts = XNEW (struct iv_to_split);
+ ivts->insn = insn;
+ ivts->base_var = NULL_RTX;
+ ivts->step = iv.step;
+ ivts->n_loc = 1;
+ ivts->loc[0] = 1;
+
+ return ivts;
+}
+
+/* Determines which of insns in LOOP can be optimized.
+ Return a OPT_INFO struct with the relevant hash tables filled
+ with all insns to be optimized. The FIRST_NEW_BLOCK field
+ is undefined for the return value. */
+
+static struct opt_info *
+analyze_insns_in_loop (struct loop *loop)
+{
+ basic_block *body, bb;
+ unsigned i;
+ struct opt_info *opt_info = XCNEW (struct opt_info);
+ rtx insn;
+ struct iv_to_split *ivts = NULL;
+ struct var_to_expand *ves = NULL;
+ PTR *slot1;
+ PTR *slot2;
+ VEC (edge, heap) *edges = get_loop_exit_edges (loop);
+ edge exit;
+ bool can_apply = false;
+
+ iv_analysis_loop_init (loop);
+
+ body = get_loop_body (loop);
+
+ if (flag_split_ivs_in_unroller)
+ opt_info->insns_to_split = htab_create (5 * loop->num_nodes,
+ si_info_hash, si_info_eq, free);
+
+ /* Record the loop exit bb and loop preheader before the unrolling. */
+ opt_info->loop_preheader = loop_preheader_edge (loop)->src;
+
+ if (VEC_length (edge, edges) == 1)
+ {
+ exit = VEC_index (edge, edges, 0);
+ if (!(exit->flags & EDGE_COMPLEX))
+ {
+ opt_info->loop_exit = split_edge (exit);
+ can_apply = true;
+ }
+ }
+
+ if (flag_variable_expansion_in_unroller
+ && can_apply)
+ opt_info->insns_with_var_to_expand = htab_create (5 * loop->num_nodes,
+ ve_info_hash, ve_info_eq, free);
+
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ bb = body[i];
+ if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
+ continue;
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ if (!INSN_P (insn))
+ continue;
+
+ if (opt_info->insns_to_split)
+ ivts = analyze_iv_to_split_insn (insn);
+
+ if (ivts)
+ {
+ slot1 = htab_find_slot (opt_info->insns_to_split, ivts, INSERT);
+ *slot1 = ivts;
+ continue;
+ }
+
+ if (opt_info->insns_with_var_to_expand)
+ ves = analyze_insn_to_expand_var (loop, insn);
+
+ if (ves)
+ {
+ slot2 = htab_find_slot (opt_info->insns_with_var_to_expand, ves, INSERT);
+ *slot2 = ves;
+ }
+ }
+ }
+
+ VEC_free (edge, heap, edges);
+ free (body);
+ return opt_info;
+}
+
+/* Called just before loop duplication. Records start of duplicated area
+ to OPT_INFO. */
+
+static void
+opt_info_start_duplication (struct opt_info *opt_info)
+{
+ if (opt_info)
+ opt_info->first_new_block = last_basic_block;
+}
+
+/* Determine the number of iterations between initialization of the base
+ variable and the current copy (N_COPY). N_COPIES is the total number
+ of newly created copies. UNROLLING is true if we are unrolling
+ (not peeling) the loop. */
+
+static unsigned
+determine_split_iv_delta (unsigned n_copy, unsigned n_copies, bool unrolling)
+{
+ if (unrolling)
+ {
+ /* If we are unrolling, initialization is done in the original loop
+ body (number 0). */
+ return n_copy;
+ }
+ else
+ {
+ /* If we are peeling, the copy in that the initialization occurs has
+ number 1. The original loop (number 0) is the last. */
+ if (n_copy)
+ return n_copy - 1;
+ else
+ return n_copies;
+ }
+}
+
+/* Locate in EXPR the expression corresponding to the location recorded
+ in IVTS, and return a pointer to the RTX for this location. */
+
+static rtx *
+get_ivts_expr (rtx expr, struct iv_to_split *ivts)
+{
+ unsigned i;
+ rtx *ret = &expr;
+
+ for (i = 0; i < ivts->n_loc; i++)
+ ret = &XEXP (*ret, ivts->loc[i]);
+
+ return ret;
+}
+
+/* Allocate basic variable for the induction variable chain. Callback for
+ htab_traverse. */
+
+static int
+allocate_basic_variable (void **slot, void *data ATTRIBUTE_UNUSED)
+{
+ struct iv_to_split *ivts = *slot;
+ rtx expr = *get_ivts_expr (single_set (ivts->insn), ivts);
+
+ ivts->base_var = gen_reg_rtx (GET_MODE (expr));
+
+ return 1;
+}
+
+/* Insert initialization of basic variable of IVTS before INSN, taking
+ the initial value from INSN. */
+
+static void
+insert_base_initialization (struct iv_to_split *ivts, rtx insn)
+{
+ rtx expr = copy_rtx (*get_ivts_expr (single_set (insn), ivts));
+ rtx seq;
+
+ start_sequence ();
+ expr = force_operand (expr, ivts->base_var);
+ if (expr != ivts->base_var)
+ emit_move_insn (ivts->base_var, expr);
+ seq = get_insns ();
+ end_sequence ();
+
+ emit_insn_before (seq, insn);
+}
+
+/* Replace the use of induction variable described in IVTS in INSN
+ by base variable + DELTA * step. */
+
+static void
+split_iv (struct iv_to_split *ivts, rtx insn, unsigned delta)
+{
+ rtx expr, *loc, seq, incr, var;
+ enum machine_mode mode = GET_MODE (ivts->base_var);
+ rtx src, dest, set;
+
+ /* Construct base + DELTA * step. */
+ if (!delta)
+ expr = ivts->base_var;
+ else
+ {
+ incr = simplify_gen_binary (MULT, mode,
+ ivts->step, gen_int_mode (delta, mode));
+ expr = simplify_gen_binary (PLUS, GET_MODE (ivts->base_var),
+ ivts->base_var, incr);
+ }
+
+ /* Figure out where to do the replacement. */
+ loc = get_ivts_expr (single_set (insn), ivts);
+
+ /* If we can make the replacement right away, we're done. */
+ if (validate_change (insn, loc, expr, 0))
+ return;
+
+ /* Otherwise, force EXPR into a register and try again. */
+ start_sequence ();
+ var = gen_reg_rtx (mode);
+ expr = force_operand (expr, var);
+ if (expr != var)
+ emit_move_insn (var, expr);
+ seq = get_insns ();
+ end_sequence ();
+ emit_insn_before (seq, insn);
+
+ if (validate_change (insn, loc, var, 0))
+ return;
+
+ /* The last chance. Try recreating the assignment in insn
+ completely from scratch. */
+ set = single_set (insn);
+ gcc_assert (set);
+
+ start_sequence ();
+ *loc = var;
+ src = copy_rtx (SET_SRC (set));
+ dest = copy_rtx (SET_DEST (set));
+ src = force_operand (src, dest);
+ if (src != dest)
+ emit_move_insn (dest, src);
+ seq = get_insns ();
+ end_sequence ();
+
+ emit_insn_before (seq, insn);
+ delete_insn (insn);
+}
+
+
+/* Return one expansion of the accumulator recorded in struct VE. */
+
+static rtx
+get_expansion (struct var_to_expand *ve)
+{
+ rtx reg;
+
+ if (ve->reuse_expansion == 0)
+ reg = ve->reg;
+ else
+ reg = VEC_index (rtx, ve->var_expansions, ve->reuse_expansion - 1);
+
+ if (VEC_length (rtx, ve->var_expansions) == (unsigned) ve->reuse_expansion)
+ ve->reuse_expansion = 0;
+ else
+ ve->reuse_expansion++;
+
+ return reg;
+}
+
+
+/* Given INSN replace the uses of the accumulator recorded in VE
+ with a new register. */
+
+static void
+expand_var_during_unrolling (struct var_to_expand *ve, rtx insn)
+{
+ rtx new_reg, set;
+ bool really_new_expansion = false;
+
+ set = single_set (insn);
+ gcc_assert (set);
+
+ /* Generate a new register only if the expansion limit has not been
+ reached. Else reuse an already existing expansion. */
+ if (PARAM_VALUE (PARAM_MAX_VARIABLE_EXPANSIONS) > ve->expansion_count)
+ {
+ really_new_expansion = true;
+ new_reg = gen_reg_rtx (GET_MODE (ve->reg));
+ }
+ else
+ new_reg = get_expansion (ve);
+
+ validate_change (insn, &SET_DEST (set), new_reg, 1);
+ validate_change (insn, &XEXP (SET_SRC (set), 0), new_reg, 1);
+
+ if (apply_change_group ())
+ if (really_new_expansion)
+ {
+ VEC_safe_push (rtx, heap, ve->var_expansions, new_reg);
+ ve->expansion_count++;
+ }
+}
+
+/* Initialize the variable expansions in loop preheader.
+ Callbacks for htab_traverse. PLACE_P is the loop-preheader
+ basic block where the initialization of the expansions
+ should take place. */
+
+static int
+insert_var_expansion_initialization (void **slot, void *place_p)
+{
+ struct var_to_expand *ve = *slot;
+ basic_block place = (basic_block)place_p;
+ rtx seq, var, zero_init, insn;
+ unsigned i;
+
+ if (VEC_length (rtx, ve->var_expansions) == 0)
+ return 1;
+
+ start_sequence ();
+ if (ve->op == PLUS || ve->op == MINUS)
+ for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
+ {
+ zero_init = CONST0_RTX (GET_MODE (var));
+ emit_move_insn (var, zero_init);
+ }
+ else if (ve->op == MULT)
+ for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
+ {
+ zero_init = CONST1_RTX (GET_MODE (var));
+ emit_move_insn (var, zero_init);
+ }
+
+ seq = get_insns ();
+ end_sequence ();
+
+ insn = BB_HEAD (place);
+ while (!NOTE_INSN_BASIC_BLOCK_P (insn))
+ insn = NEXT_INSN (insn);
+
+ emit_insn_after (seq, insn);
+ /* Continue traversing the hash table. */
+ return 1;
+}
+
+/* Combine the variable expansions at the loop exit.
+ Callbacks for htab_traverse. PLACE_P is the loop exit
+ basic block where the summation of the expansions should
+ take place. */
+
+static int
+combine_var_copies_in_loop_exit (void **slot, void *place_p)
+{
+ struct var_to_expand *ve = *slot;
+ basic_block place = (basic_block)place_p;
+ rtx sum = ve->reg;
+ rtx expr, seq, var, insn;
+ unsigned i;
+
+ if (VEC_length (rtx, ve->var_expansions) == 0)
+ return 1;
+
+ start_sequence ();
+ if (ve->op == PLUS || ve->op == MINUS)
+ for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
+ {
+ sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg),
+ var, sum);
+ }
+ else if (ve->op == MULT)
+ for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
+ {
+ sum = simplify_gen_binary (MULT, GET_MODE (ve->reg),
+ var, sum);
+ }
+
+ expr = force_operand (sum, ve->reg);
+ if (expr != ve->reg)
+ emit_move_insn (ve->reg, expr);
+ seq = get_insns ();
+ end_sequence ();
+
+ insn = BB_HEAD (place);
+ while (!NOTE_INSN_BASIC_BLOCK_P (insn))
+ insn = NEXT_INSN (insn);
+
+ emit_insn_after (seq, insn);
+
+ /* Continue traversing the hash table. */
+ return 1;
+}
+
+/* Apply loop optimizations in loop copies using the
+ data which gathered during the unrolling. Structure
+ OPT_INFO record that data.
+
+ UNROLLING is true if we unrolled (not peeled) the loop.
+ REWRITE_ORIGINAL_BODY is true if we should also rewrite the original body of
+ the loop (as it should happen in complete unrolling, but not in ordinary
+ peeling of the loop). */
+
+static void
+apply_opt_in_copies (struct opt_info *opt_info,
+ unsigned n_copies, bool unrolling,
+ bool rewrite_original_loop)
+{
+ unsigned i, delta;
+ basic_block bb, orig_bb;
+ rtx insn, orig_insn, next;
+ struct iv_to_split ivts_templ, *ivts;
+ struct var_to_expand ve_templ, *ves;
+
+ /* Sanity check -- we need to put initialization in the original loop
+ body. */
+ gcc_assert (!unrolling || rewrite_original_loop);
+
+ /* Allocate the basic variables (i0). */
+ if (opt_info->insns_to_split)
+ htab_traverse (opt_info->insns_to_split, allocate_basic_variable, NULL);
+
+ for (i = opt_info->first_new_block; i < (unsigned) last_basic_block; i++)
+ {
+ bb = BASIC_BLOCK (i);
+ orig_bb = get_bb_original (bb);
+
+ /* bb->aux holds position in copy sequence initialized by
+ duplicate_loop_to_header_edge. */
+ delta = determine_split_iv_delta ((size_t)bb->aux, n_copies,
+ unrolling);
+ bb->aux = 0;
+ orig_insn = BB_HEAD (orig_bb);
+ for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb)); insn = next)
+ {
+ next = NEXT_INSN (insn);
+ if (!INSN_P (insn))
+ continue;
+
+ while (!INSN_P (orig_insn))
+ orig_insn = NEXT_INSN (orig_insn);
+
+ ivts_templ.insn = orig_insn;
+ ve_templ.insn = orig_insn;
+
+ /* Apply splitting iv optimization. */
+ if (opt_info->insns_to_split)
+ {
+ ivts = htab_find (opt_info->insns_to_split, &ivts_templ);
+
+ if (ivts)
+ {
+ gcc_assert (GET_CODE (PATTERN (insn))
+ == GET_CODE (PATTERN (orig_insn)));
+
+ if (!delta)
+ insert_base_initialization (ivts, insn);
+ split_iv (ivts, insn, delta);
+ }
+ }
+ /* Apply variable expansion optimization. */
+ if (unrolling && opt_info->insns_with_var_to_expand)
+ {
+ ves = htab_find (opt_info->insns_with_var_to_expand, &ve_templ);
+ if (ves)
+ {
+ gcc_assert (GET_CODE (PATTERN (insn))
+ == GET_CODE (PATTERN (orig_insn)));
+ expand_var_during_unrolling (ves, insn);
+ }
+ }
+ orig_insn = NEXT_INSN (orig_insn);
+ }
+ }
+
+ if (!rewrite_original_loop)
+ return;
+
+ /* Initialize the variable expansions in the loop preheader
+ and take care of combining them at the loop exit. */
+ if (opt_info->insns_with_var_to_expand)
+ {
+ htab_traverse (opt_info->insns_with_var_to_expand,
+ insert_var_expansion_initialization,
+ opt_info->loop_preheader);
+ htab_traverse (opt_info->insns_with_var_to_expand,
+ combine_var_copies_in_loop_exit,
+ opt_info->loop_exit);
+ }
+
+ /* Rewrite also the original loop body. Find them as originals of the blocks
+ in the last copied iteration, i.e. those that have
+ get_bb_copy (get_bb_original (bb)) == bb. */
+ for (i = opt_info->first_new_block; i < (unsigned) last_basic_block; i++)
+ {
+ bb = BASIC_BLOCK (i);
+ orig_bb = get_bb_original (bb);
+ if (get_bb_copy (orig_bb) != bb)
+ continue;
+
+ delta = determine_split_iv_delta (0, n_copies, unrolling);
+ for (orig_insn = BB_HEAD (orig_bb);
+ orig_insn != NEXT_INSN (BB_END (bb));
+ orig_insn = next)
+ {
+ next = NEXT_INSN (orig_insn);
+
+ if (!INSN_P (orig_insn))
+ continue;
+
+ ivts_templ.insn = orig_insn;
+ if (opt_info->insns_to_split)
+ {
+ ivts = htab_find (opt_info->insns_to_split, &ivts_templ);
+ if (ivts)
+ {
+ if (!delta)
+ insert_base_initialization (ivts, orig_insn);
+ split_iv (ivts, orig_insn, delta);
+ continue;
+ }
+ }
+
+ }
+ }
+}
+
+/* Release the data structures used for the variable expansion
+ optimization. Callbacks for htab_traverse. */
+
+static int
+release_var_copies (void **slot, void *data ATTRIBUTE_UNUSED)
+{
+ struct var_to_expand *ve = *slot;
+
+ VEC_free (rtx, heap, ve->var_expansions);
+
+ /* Continue traversing the hash table. */
+ return 1;
+}
+
+/* Release OPT_INFO. */
+
+static void
+free_opt_info (struct opt_info *opt_info)
+{
+ if (opt_info->insns_to_split)
+ htab_delete (opt_info->insns_to_split);
+ if (opt_info->insns_with_var_to_expand)
+ {
+ htab_traverse (opt_info->insns_with_var_to_expand,
+ release_var_copies, NULL);
+ htab_delete (opt_info->insns_with_var_to_expand);
+ }
+ free (opt_info);
+}
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