Hi,
so I've dusted off and improved the implementation of unroll-and-jam from
last year. The changes relative to last submission are:
* corrected feasibility of the transform (i.e. that dependency directions
are correctly retained, the last submission was wrong).
* added profitability analysis (here only very simple, but obvious: we
regard it profitable only when memory references go away because they
access the same elements after unroll-jamming) can be changed with a
param
* moved the thing into its own file
* run it always when active, not only when loop splitting didn't do
anything
* added a testcase showing various examples for when the transformation is
valid and invalid
The profitability is measured in percentages of memory references going
away.
The core unroll and fusing implementation is still the same. The file
comment explains the transformation, but to recap, unroll-and-jam
transforms this loop nest:
for (j = 0; j < n; j++)
for (i = 0; i < n; i++)
d[j][i] = a[j][i] * a[j+1][i];
into
for (j = 0; j < n; j += 2)
for (i = 0; i < n; i++)
d[j][i] = a[j][i] * a[j+1][i],
d[j+1][i] = a[j+1][i] * a[j+2][i];
(this is an example of one memref going away).
I've tested it on SPEC2006, with profitability active it transforms 100
loops in seven benchmarks, without effects on performance. Without
profitability it can transform 3353 loops but makes 481.wrf regress by
about 10%.
Regstrapped on x86-64-linux with all languages+Ada (on a two weeks old
trunk, retesting in progress). Okay for trunk?
Ciao,
Michael.
commit 7bc718fa3476f7f6f72c2220cba288458fd1406e
Author: Michael Matz <m...@suse.de>
Date: Fri Nov 17 13:49:39 2017 +0100
Add unroll and jam pass
* gimple-loop-jam.c: New file.
* Makefile.in (OBJS): Add gimple-loop-jam.o.
* common.opt (funroll-and-jam): New option.
* opts.c (default_options_table): Add unroll-and-jam at -O3.
* params.def (PARAM_UNROLL_JAM_MIN_PERCENT): New param.
* passes.def: Add pass_loop_jam.
* timevar.def (TV_LOOP_JAM): Add.
* tree-pass.h (make_pass_loop_jam): Declare.
* doc/invoke.texi (-funroll-and-jam): Document new option.
(unroll-jam-min-percent): Document new param.
testsuite/
* gcc.dg/unroll-and-jam.c: New test.
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 5db7855..8da4bf4 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1298,6 +1298,7 @@ OBJS = \
gimple-iterator.o \
gimple-fold.o \
gimple-laddress.o \
+ gimple-loop-jam.o \
gimple-low.o \
gimple-pretty-print.o \
gimple-ssa-backprop.o \
diff --git a/gcc/common.opt b/gcc/common.opt
index f8f2ed3..c9875f7 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2695,6 +2695,10 @@ fsplit-loops
Common Report Var(flag_split_loops) Optimization
Perform loop splitting.
+funroll-and-jam
+Common Report Var(flag_unroll_jam) Optimization
+Perform unroll-and-jam on loops.
+
funwind-tables
Common Report Var(flag_unwind_tables) Optimization
Just generate unwind tables for exception handling.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 1e2b869..36a165b 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -437,7 +437,7 @@ Objective-C and Objective-C++ Dialects}.
-ftree-reassoc -ftree-sink -ftree-slsr -ftree-sra @gol
-ftree-switch-conversion -ftree-tail-merge @gol
-ftree-ter -ftree-vectorize -ftree-vrp -funconstrained-commons @gol
--funit-at-a-time -funroll-all-loops -funroll-loops @gol
+-funit-at-a-time -funroll-all-loops -funroll-loops -funroll-and-jam @gol
-funsafe-math-optimizations -funswitch-loops @gol
-fipa-ra -fvariable-expansion-in-unroller -fvect-cost-model -fvpt @gol
-fweb -fwhole-program -fwpa -fuse-linker-plugin @gol
@@ -9774,6 +9774,12 @@ for one side of the iteration space and false for the
other.
Move branches with loop invariant conditions out of the loop, with duplicates
of the loop on both branches (modified according to result of the condition).
+@item -funroll-and-jam
+@opindex funroll-and-jam
+Apply unroll and jam transoformations on feasible loops. In a loop
+nest this unrolls the outer loop by some factor and fuses the resulting
+multiple inner loops.
+
@item -ffunction-sections
@itemx -fdata-sections
@opindex ffunction-sections
@@ -10835,6 +10841,10 @@ we may be able to devirtualize speculatively.
@item max-vrp-switch-assertions
The maximum number of assertions to add along the default edge of a switch
statement during VRP. The default is 10.
+
+@item unroll-jam-min-percent
+The minimum percentage of memory references that must be optimized
+away for the unroll-and-jam transformation to be considered profitable.
@end table
@end table
diff --git a/gcc/gimple-loop-jam.c b/gcc/gimple-loop-jam.c
new file mode 100644
index 0000000..b5d45db
--- /dev/null
+++ b/gcc/gimple-loop-jam.c
@@ -0,0 +1,579 @@
+/* Loop unroll-and-jam.
+ Copyright (C) 2017 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 3, 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 COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "params.h"
+#include "tree-pass.h"
+#include "backend.h"
+#include "tree.h"
+#include "gimple.h"
+#include "ssa.h"
+#include "fold-const.h"
+#include "tree-cfg.h"
+#include "tree-ssa.h"
+#include "tree-ssa-loop-niter.h"
+#include "tree-ssa-loop.h"
+#include "tree-ssa-loop-manip.h"
+#include "cfgloop.h"
+#include "tree-scalar-evolution.h"
+#include "gimple-iterator.h"
+#include "cfghooks.h"
+#include "tree-data-ref.h"
+#include "tree-ssa-loop-ivopts.h"
+#include "tree-vectorizer.h"
+
+/* Unroll and Jam transformation
+
+ This is a combination of two transformations, where the second
+ is not always valid. It's applicable if a loop nest has redundancies
+ over the iterations of an outer loop while not having that with
+ an inner loop.
+
+ Given this nest:
+ for (i) {
+ for (j) {
+ B(i,j)
+ }
+ }
+
+ first unroll:
+ for (i by 2) {
+ for (j) {
+ B(i,j)
+ }
+ for (j) {
+ B(i+1,j)
+ }
+ }
+
+ then fuse the two adjacent inner loops resulting from that:
+ for (i by 2) {
+ for (j) {
+ B(i,j)
+ B(i+1,j)
+ }
+ }
+
+ As the order of evaluations of the body B changes this is valid
+ only in certain situations: all distance vectors need to be forward.
+ Additionally if there are multiple induction variables than just
+ a counting control IV (j above) we can also deal with some situations.
+
+ The validity is checked by unroll_jam_possible_p, and the data-dep
+ testing below.
+
+ A trivial example where the fusion is wrong would be when
+ B(i,j) == x[j-1] = x[j];
+ for (i by 2) {
+ for (j) {
+ x[j-1] = x[j];
+ }
+ for (j) {
+ x[j-1] = x[j];
+ }
+ } effect: move content to front by two elements
+ -->
+ for (i by 2) {
+ for (j) {
+ x[j-1] = x[j];
+ x[j-1] = x[j];
+ }
+ } effect: move content to front by one element
+*/
+
+/* Modify the loop tree for the fact that all code once belonging
+ to the OLD loop or the outer loop of OLD now is inside LOOP. */
+
+static void
+fix_loop_structure (struct loop *loop, struct loop *old)
+{
+ basic_block *bbs;
+ int i, n;
+ struct loop *subloop;
+ edge e;
+ edge_iterator ei;
+
+ /* Find its nodes. */
+ bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun));
+ n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun));
+
+ for (i = 0; i < n; i++)
+ {
+ /* If the block was direct child of OLD loop it's now part
+ of LOOP. If it was outside OLD, then it moved into LOOP
+ as well. This avoids changing the loop father for BBs
+ in inner loops of OLD. */
+ if (bbs[i]->loop_father == old
+ || loop_depth (bbs[i]->loop_father) < loop_depth (old))
+ {
+ remove_bb_from_loops (bbs[i]);
+ add_bb_to_loop (bbs[i], loop);
+ continue;
+ }
+
+ /* If we find a direct subloop of OLD, move it to LOOP. */
+ subloop = bbs[i]->loop_father;
+ if (loop_outer (subloop) == old && subloop->header == bbs[i])
+ {
+ flow_loop_tree_node_remove (subloop);
+ flow_loop_tree_node_add (loop, subloop);
+ }
+ }
+
+ /* Update the information about loop exit edges. */
+ for (i = 0; i < n; i++)
+ {
+ FOR_EACH_EDGE (e, ei, bbs[i]->succs)
+ {
+ rescan_loop_exit (e, false, false);
+ }
+ }
+
+ loop->num_nodes = n;
+
+ free (bbs);
+}
+
+/* BB exits the outer loop of an unroll-and-jam situation.
+ Check if any statements therein would prevent the transformation. */
+
+static bool
+bb_prevents_fusion_p (basic_block bb)
+{
+ gimple_stmt_iterator gsi;
+ /* BB is duplicated by outer unrolling and then all N-1 first copies
+ move into the body of the fused inner loop. The last copy remains
+ the exit block of the outer loop and is still outside the inner loop
+ also after fusion. We can't allow this for some effects of BB:
+ * stores or unknown side-effects prevent fusion
+ * loads don't
+ * computations into SSA names: these aren't problematic. Their
+ result will be unused on the exit edges of the first N-1 copies
+ (those aren't taken after unrolling). If they are used on the
+ other edge (the one leading to the outer latch block) they are
+ loop-carried (on the outer loop) and the Nth copy of BB will
+ compute them again (i.e. the first N-1 copies will be dead). */
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *g = gsi_stmt (gsi);
+ if (gimple_vdef (g))
+ return true;
+ }
+ return false;
+}
+
+/* Given an inner loop LOOP (of some OUTER loop) determine if
+ we can safely fuse copies of it (generated by outer unrolling).
+ If so return true, otherwise return false. */
+
+static bool
+unroll_jam_possible_p (struct loop *outer, struct loop *loop)
+{
+ basic_block *bbs;
+ int i, n;
+ struct tree_niter_desc niter;
+
+ /* When fusing the loops we skip the latch block
+ of the first one, so it mustn't have any effects to
+ preserve. */
+ if (!empty_block_p (loop->latch))
+ return false;
+
+ if (!single_exit (loop))
+ return false;
+
+ /* We need a perfect nest. Quick check for adjacent inner loops. */
+ if (outer->inner != loop || loop->next)
+ return false;
+
+ /* The number of iterations of the inner loop must be loop invariant
+ with respect to the outer loop. */
+ if (!number_of_iterations_exit (loop, single_exit (loop), &niter,
+ false, true)
+ || niter.cmp == ERROR_MARK
+ || !expr_invariant_in_loop_p (outer, niter.niter))
+ return false;
+
+ /* And check blocks belonging to just outer loop. */
+ bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun));
+ n = get_loop_body_with_size (outer, bbs, n_basic_blocks_for_fn (cfun));
+
+ for (i = 0; i < n; i++)
+ {
+ if (bbs[i]->loop_father == outer
+ && bbs[i] != outer->latch && bbs[i] != outer->header
+ && (!loop_exits_from_bb_p (outer, bbs[i])
+ || bb_prevents_fusion_p (bbs[i])))
+ break;
+ /* XXX Note that the above disallows head-controlled inner loops,
+ that we usually have. The guard block would need to be accepted
+ (invariant condition either entering or skipping the loop),
+ without also accepting arbitrary control flow. When unswitching
+ ran before us (as with -O3) this won't be a problem because its
+ outer loop unswitching will have moved out the invariant condition.
+
+ If we do that we need to extend fuse_loops() to cope with this
+ by threading through the (still invariant) copied condition
+ between the two loop copies. */
+ }
+ free (bbs);
+ if (i != n)
+ return false;
+
+ /* For now we can safely fuse copies of LOOP only if all
+ loop carried variables are inductions (or the virtual op).
+
+ We could handle reductions as well (the initial value in the second
+ body would be the after-iter value of the first body) if it's over
+ an associative and commutative operation. We wouldn't
+ be able to handle unknown cycles. */
+ gphi_iterator psi;
+ for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
+ {
+ affine_iv iv;
+ tree op = gimple_phi_result (psi.phi ());
+
+ if (virtual_operand_p (op))
+ continue;
+ if (!simple_iv (loop, loop, op, &iv, true))
+ return false;
+ /* The inductions must be regular, loop invariant step and initial
+ value. */
+ if (!expr_invariant_in_loop_p (outer, iv.step)
+ || !expr_invariant_in_loop_p (outer, iv.base))
+ return false;
+ /* XXX With more effort we could also be able to deal with inductions
+ where the initial value is loop variant but a simple IV in the
+ outer loop. The initial value for the second body would be
+ the original initial value plus iv.base.step. The next value
+ for the fused loop would be the original next value of the first
+ copy, _not_ the next value of the second body. */
+ }
+
+ return true;
+}
+
+/* Fuse LOOP with all further neighbors. The loops are expected to
+ be in appropriate form. */
+
+static void
+fuse_loops (struct loop *loop)
+{
+ struct loop *next = loop->next;
+
+ while (next)
+ {
+ edge e;
+
+ remove_branch (single_pred_edge (loop->latch));
+ /* Make delete_basic_block not fiddle with the loop structure. */
+ basic_block oldlatch = loop->latch;
+ loop->latch = NULL;
+ delete_basic_block (oldlatch);
+ e = redirect_edge_and_branch (loop_latch_edge (next),
+ loop->header);
+ loop->latch = e->src;
+ flush_pending_stmts (e);
+
+ gcc_assert (EDGE_COUNT (next->header->preds) == 1);
+
+ /* The PHI nodes of the second body (single-argument now)
+ need adjustments to use the right values: either directly
+ the value of the corresponding PHI in the first copy or
+ the one leaving the first body which unrolling did for us.
+
+ See also unroll_jam_possible_p() for further possibilities. */
+ gphi_iterator psi_first, psi_second;
+ e = single_pred_edge (next->header);
+ for (psi_first = gsi_start_phis (loop->header),
+ psi_second = gsi_start_phis (next->header);
+ !gsi_end_p (psi_first);
+ gsi_next (&psi_first), gsi_next (&psi_second))
+ {
+ gphi *phi_first = psi_first.phi ();
+ gphi *phi_second = psi_second.phi ();
+ tree firstop = gimple_phi_result (phi_first);
+ /* The virtual operand is correct already as it's
+ always live at exit, hence has a LCSSA node and outer
+ loop unrolling updated SSA form. */
+ if (virtual_operand_p (firstop))
+ continue;
+
+ /* Due to unroll_jam_possible_p() we know that this is
+ an induction. The second body goes over the same
+ iteration space. */
+ add_phi_arg (phi_second, firstop, e,
+ gimple_location (phi_first));
+ }
+ gcc_assert (gsi_end_p (psi_second));
+
+ fix_loop_structure (loop, next);
+ gcc_assert (!next->num_nodes);
+ struct loop *ln = next->next;
+ delete_loop (next);
+ next = ln;
+ }
+ rewrite_into_loop_closed_ssa_1 (NULL, 0, SSA_OP_USE, loop);
+}
+
+/* Returns true if the distance in DDR can be determined and adjusts
+ the unroll factor in *UNROLL to be valid for that distance. If this
+ data dep can lead to a removed memory reference, increment *REMOVED
+ and adjust *PROFIT_UNROLL to be the necessary unroll factor for this
+ to happen. Otherwise returns false. */
+
+static bool
+determine_reuse (struct data_dependence_relation *ddr,
+ unsigned *unroll, unsigned *profit_unroll, unsigned *removed)
+{
+ bool ret = false;
+ if (DDR_ARE_DEPENDENT (ddr) != chrec_known)
+ {
+ if (DDR_NUM_DIST_VECTS (ddr) == 0)
+ return false;
+ unsigned i;
+ lambda_vector dist_v;
+ FOR_EACH_VEC_ELT (DDR_DIST_VECTS (ddr), i, dist_v)
+ {
+ /* A distance (a,b) is at worst transformed into (a/N,b) by the
+ unrolling (factor N), so the transformation is valid if
+ a >= N, or b > 0, or b is zero and a > 0. Otherwise the unroll
+ factor needs to be limited so that the first condition holds.
+ That may limit the factor down to zero in the worst case. */
+ int dist = dist_v[0];
+ if (dist < 0)
+ gcc_unreachable ();
+ else if ((unsigned)dist >= *unroll)
+ ;
+ else if (lambda_vector_lexico_pos (dist_v + 1, DDR_NB_LOOPS (ddr) - 1)
+ || (lambda_vector_zerop (dist_v + 1, DDR_NB_LOOPS (ddr) - 1)
+ && dist > 0))
+ ;
+ else
+ *unroll = dist;
+
+ /* With a distance (a,0) it's always profitable to unroll-and-jam
+ (by a+1), because one memory reference will go away. With
+ (a,b) and b != 0 that's less clear. We will increase the
+ number of streams without lowering the number of mem refs.
+ So for now only handle the first situation. */
+ if (lambda_vector_zerop (dist_v + 1, DDR_NB_LOOPS (ddr) - 1))
+ {
+ *profit_unroll = MAX (*profit_unroll, (unsigned)dist + 1);
+ (*removed)++;
+ }
+
+ ret = true;
+ }
+ }
+ return ret;
+}
+
+/* Reverse the ->next list starting at loop L. No code transformation
+ is done, it's purely internal. */
+
+static struct loop *
+reverse_list (struct loop *l)
+{
+ struct loop *prev = 0, *next;
+ for (; l; l = next)
+ {
+ next = l->next;
+ l->next = prev;
+ prev = l;
+ }
+ return prev;
+}
+
+/* Main entry point for the unroll-and-jam transformation
+ described above. */
+
+static unsigned int
+tree_loop_unroll_and_jam (void)
+{
+ struct loop *loop;
+ bool changed = false;
+
+ gcc_assert (scev_initialized_p ());
+
+ /* Go through all innermost loops. */
+ FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST)
+ {
+ struct loop *outer = loop_outer (loop);
+
+ if (loop_depth (loop) < 2
+ || optimize_loop_for_size_p (loop))
+ continue;
+
+ if (!unroll_jam_possible_p (outer, loop))
+ continue;
+
+ vec<data_reference_p> datarefs;
+ vec<ddr_p> dependences;
+ unsigned unroll_factor, profit_unroll, removed;
+ struct tree_niter_desc desc;
+ bool unroll = false;
+
+ auto_vec<loop_p, 3> loop_nest;
+ dependences.create (10);
+ datarefs.create (10);
+ if (!compute_data_dependences_for_loop (outer, true, &loop_nest,
+ &datarefs, &dependences))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Cannot analyze data dependencies\n");
+ free_data_refs (datarefs);
+ free_dependence_relations (dependences);
+ return false;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ dump_data_dependence_relations (dump_file, dependences);
+
+ unroll_factor = (unsigned)-1;
+ profit_unroll = 1;
+ removed = 0;
+
+ /* Check all dependencies. */
+ unsigned i;
+ struct data_dependence_relation *ddr;
+ FOR_EACH_VEC_ELT (dependences, i, ddr)
+ {
+ struct data_reference *dra, *drb;
+
+ /* If the refs are independend there's nothing to do. */
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
+ continue;
+ dra = DDR_A (ddr);
+ drb = DDR_B (ddr);
+ /* Nothing interesting for the self dependencies. */
+ if (dra == drb)
+ continue;
+
+ /* Now check the distance vector, for determining a sensible
+ outer unroll factor, and for validity of merging the inner
+ loop copies. */
+ if (!determine_reuse (ddr, &unroll_factor, &profit_unroll, &removed))
+ {
+ /* Couldn't get the distance vector. For two reads that's
+ harmless (we assume we should unroll). For at least
+ one write this means we can't check the dependence direction
+ and hence can't determine safety. */
+
+ if (DR_IS_WRITE (dra) || DR_IS_WRITE (drb))
+ {
+ unroll_factor = 0;
+ break;
+ }
+ }
+ }
+
+ /* We regard a user-specified minimum percentage of zero as a request
+ to ignore all profitability concerns and apply the transformation
+ always. */
+ if (!PARAM_VALUE (PARAM_UNROLL_JAM_MIN_PERCENT))
+ profit_unroll = 2;
+ if (removed * 100 / datarefs.length ()
+ < (unsigned)PARAM_VALUE (PARAM_UNROLL_JAM_MIN_PERCENT))
+ profit_unroll = 1;
+ if (unroll_factor > profit_unroll)
+ unroll_factor = profit_unroll;
+ if (unroll_factor > 4)
+ unroll_factor = 4;
+ unroll = (unroll_factor > 1
+ && can_unroll_loop_p (outer, unroll_factor, &desc));
+
+ if (unroll)
+ {
+ if (dump_enabled_p ())
+ dump_printf_loc (MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS,
+ find_loop_location (outer),
+ "applying unroll and jam with factor %d\n",
+ unroll_factor);
+ initialize_original_copy_tables ();
+ tree_unroll_loop (outer, unroll_factor, single_dom_exit (outer),
+ &desc);
+ free_original_copy_tables ();
+ outer->inner = reverse_list (outer->inner);
+ fuse_loops (outer->inner);
+ changed = true;
+ }
+
+ loop_nest.release ();
+ free_dependence_relations (dependences);
+ free_data_refs (datarefs);
+ }
+
+ if (changed)
+ {
+ scev_reset ();
+ free_dominance_info (CDI_DOMINATORS);
+ return TODO_cleanup_cfg;
+ }
+ return 0;
+}
+
+/* Pass boilerplate */
+
+namespace {
+
+const pass_data pass_data_loop_jam =
+{
+ GIMPLE_PASS, /* type */
+ "unrolljam", /* name */
+ OPTGROUP_LOOP, /* optinfo_flags */
+ TV_LOOP_JAM, /* tv_id */
+ PROP_cfg, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0, /* todo_flags_finish */
+};
+
+class pass_loop_jam : public gimple_opt_pass
+{
+public:
+ pass_loop_jam (gcc::context *ctxt)
+ : gimple_opt_pass (pass_data_loop_jam, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *) { return flag_unroll_jam != 0; }
+ virtual unsigned int execute (function *);
+
+};
+
+unsigned int
+pass_loop_jam::execute (function *fun)
+{
+ if (number_of_loops (fun) <= 1)
+ return 0;
+
+ return tree_loop_unroll_and_jam ();
+}
+
+}
+
+gimple_opt_pass *
+make_pass_loop_jam (gcc::context *ctxt)
+{
+ return new pass_loop_jam (ctxt);
+}
diff --git a/gcc/opts.c b/gcc/opts.c
index ab3f4ae..9da2ba6 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -535,6 +535,7 @@ static const struct default_options default_options_table[]
=
{ OPT_LEVELS_1_PLUS_NOT_DEBUG, OPT_finline_functions_called_once, NULL, 1
},
{ OPT_LEVELS_3_PLUS, OPT_fsplit_loops, NULL, 1 },
{ OPT_LEVELS_3_PLUS, OPT_funswitch_loops, NULL, 1 },
+ { OPT_LEVELS_3_PLUS, OPT_funroll_and_jam, NULL, 1 },
{ OPT_LEVELS_3_PLUS, OPT_fgcse_after_reload, NULL, 1 },
{ OPT_LEVELS_3_PLUS, OPT_ftree_loop_vectorize, NULL, 1 },
{ OPT_LEVELS_3_PLUS, OPT_ftree_slp_vectorize, NULL, 1 },
diff --git a/gcc/params.def b/gcc/params.def
index 8881f4c..24f2e98 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -1287,6 +1287,11 @@ DEFPARAM (PARAM_VECT_EPILOGUES_NOMASK,
"Enable loop epilogue vectorization using smaller vector size.",
0, 0, 1)
+DEFPARAM(PARAM_UNROLL_JAM_MIN_PERCENT,
+ "unroll-jam-min-percent",
+ "Minimum percentage of memrefs that must go away for unroll-and-jam to
be considered profitable.",
+ 1, 0, 100)
+
/*
Local variables:
diff --git a/gcc/passes.def b/gcc/passes.def
index 00e75d2..09bea09 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -273,6 +273,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_tree_unswitch);
NEXT_PASS (pass_scev_cprop);
NEXT_PASS (pass_loop_split);
+ NEXT_PASS (pass_loop_jam);
/* All unswitching, final value replacement and splitting can expose
empty loops. Remove them now. */
NEXT_PASS (pass_cd_dce);
diff --git a/gcc/testsuite/gcc.dg/unroll-and-jam.c
b/gcc/testsuite/gcc.dg/unroll-and-jam.c
new file mode 100644
index 0000000..59d60ab
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/unroll-and-jam.c
@@ -0,0 +1,111 @@
+/* { dg-do run } */
+/* { dg-options "-O3 -funroll-and-jam --param unroll-jam-min-percent=0
-fdump-tree-unrolljam-details" } */
+/* { dg-require-effective-target int32plus } */
+
+#include <stdio.h>
+extern unsigned int a[];
+extern unsigned int b[];
+extern unsigned int aa[][1024];
+unsigned int checksum;
+void checkaa(void)
+{
+ unsigned sum = 1;
+ unsigned long i, j;
+ for (i = 0; i < 1024; i++) {
+ for (j = 0; j < 16; j++) {
+ sum += aa[j][i]*31+47;
+ }
+ }
+ checksum = checksum * 27 + sum;
+ //printf(" %d\n", sum);
+}
+
+void checkb(void)
+{
+ unsigned sum = 1;
+ unsigned long i, j;
+ for (i = 0; i < 1024; i++) {
+ sum += b[i]*31+47;
+ }
+ checksum = checksum * 27 + sum;
+ //printf(" %d\n", sum);
+}
+
+#define TEST(name, body, test) \
+static void __attribute__((noinline,noclone)) name (unsigned long n, unsigned
long m) \
+{ \
+ unsigned long i, j; \
+ for (i = 1; i < m; i++) { \
+ for (j = 1; j < n; j++) { \
+ body; \
+ } \
+ } \
+ test; \
+} \
+static void __attribute__((noinline,noclone,optimize("O1"))) name ## noopt
(unsigned long n, unsigned long m) \
+{ \
+ unsigned long i, j; \
+ for (i = 1; i < m; i++) { \
+ for (j = 1; j < n; j++) { \
+ body; \
+ } \
+ } \
+ test; \
+}
+TEST(foo1, aa[i+1][j+1]=aa[i][j] * aa[i][j] / 2, checkaa()) //ok, -1,-1
+TEST(foo2, aa[i][j+1]=3*aa[i+1][j], checkaa()) //notok, 1,-1
+TEST(foo3, aa[i+1][j-1]=aa[i][j] * aa[i][j] / 2, checkaa()) //notok, -1,1
+TEST(foo4, aa[i][j] = aa[i-1][j+1] * aa[i-1][j+1] / 2, checkaa()) //notok, -1,1
+TEST(foo5, aa[i][j] = aa[i+1][j+1] * aa[i+1][j+1] / 2, checkaa()) //ok, 1,1
+TEST(foo6, aa[i][j] = aa[i+1][j] * aa[i+1][j] / 2, checkaa()) //ok, -1,0
+TEST(foo7, aa[i+1][j] = aa[i][j] * aa[i][j] / 2, checkaa()) //ok, 1,0
+TEST(foo9, b[j] = 3*b[j+1] + 1, checkb()) //notok, 0,-1
+TEST(foo10, b[j] = 3*b[j] + 1, checkb()) //ok, 0,0
+
+/* foo8 should work as well, but currently doesn't because the distance
+ vectors we compute are too pessimistic. We compute
+ (0,1), (1,1) and (1,-1)
+ and the last one causes us to lose. */
+TEST(foo8, b[j+1] = 3*b[j] + 1, checkb()) //ok, 0,1
+
+unsigned int a[1024];
+unsigned int b[1024];
+unsigned int aa[16][1024];
+void init(void)
+{
+ unsigned long i,j;
+ for (i = 0; i < 1024; i++) {
+ for (j = 0; j < 16; j++) {
+ aa[j][i] = ((j+1)*2+i+1) % 17;
+ }
+ a[i] = ((i+1)*31) % 19;
+ b[i] = ((i+1)*47) % 23;
+ }
+ checksum = 1;
+}
+
+#define RUN(name) \
+ printf(" %s\n", #name); \
+ init();for(i=0;i<4;i++)name##noopt(32,8); checka = checksum; \
+ init();for(i=0;i<4;i++)name(32,8); \
+ printf("%sok %s\n", checka != checksum ? "NOT " : "", #name);
+
+int main()
+{
+ int i;
+ unsigned checka;
+ RUN(foo1);
+ RUN(foo2);
+ RUN(foo3);
+ RUN(foo4);
+ RUN(foo5);
+ RUN(foo6);
+ RUN(foo7);
+ RUN(foo8);
+ RUN(foo9);
+ RUN(foo10);
+ return 0;
+}
+
+/* Five loops should be unroll-jammed (actually six, but see above). */
+/* { dg-final { scan-tree-dump-times "applying unroll and jam" 5 "unrolljam" }
} */
diff --git a/gcc/timevar.def b/gcc/timevar.def
index 8cec6af..9169ca7 100644
--- a/gcc/timevar.def
+++ b/gcc/timevar.def
@@ -188,6 +188,7 @@ DEFTIMEVAR (TV_TREE_LOOP_IVCANON , "tree canonical iv")
DEFTIMEVAR (TV_SCEV_CONST , "scev constant prop")
DEFTIMEVAR (TV_TREE_LOOP_UNSWITCH , "tree loop unswitching")
DEFTIMEVAR (TV_LOOP_SPLIT , "loop splitting")
+DEFTIMEVAR (TV_LOOP_JAM , "unroll and jam")
DEFTIMEVAR (TV_COMPLETE_UNROLL , "complete unrolling")
DEFTIMEVAR (TV_TREE_PARALLELIZE_LOOPS, "tree parallelize loops")
DEFTIMEVAR (TV_TREE_VECTORIZATION , "tree vectorization")
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index 9777308..3a6d83d 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -370,6 +370,7 @@ extern gimple_opt_pass *make_pass_tree_loop_init
(gcc::context *ctxt);
extern gimple_opt_pass *make_pass_lim (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_tree_unswitch (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_loop_split (gcc::context *ctxt);
+extern gimple_opt_pass *make_pass_loop_jam (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_predcom (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_iv_canon (gcc::context *ctxt);
extern gimple_opt_pass *make_pass_scev_cprop (gcc::context *ctxt);
