1.1 --- a/src/share/vm/opto/loopopts.cpp Mon Mar 21 02:30:49 2011 -0700
1.2 +++ b/src/share/vm/opto/loopopts.cpp Mon Mar 21 11:28:14 2011 -0700
1.3 @@ -42,13 +42,13 @@
1.4 return NULL;
1.5 }
1.6 int wins = 0;
1.7 - assert( !n->is_CFG(), "" );
1.8 - assert( region->is_Region(), "" );
1.9 + assert(!n->is_CFG(), "");
1.10 + assert(region->is_Region(), "");
1.11
1.12 const Type* type = n->bottom_type();
1.13 const TypeOopPtr *t_oop = _igvn.type(n)->isa_oopptr();
1.14 Node *phi;
1.15 - if( t_oop != NULL && t_oop->is_known_instance_field() ) {
1.16 + if (t_oop != NULL && t_oop->is_known_instance_field()) {
1.17 int iid = t_oop->instance_id();
1.18 int index = C->get_alias_index(t_oop);
1.19 int offset = t_oop->offset();
1.20 @@ -57,20 +57,20 @@
1.21 phi = PhiNode::make_blank(region, n);
1.22 }
1.23 uint old_unique = C->unique();
1.24 - for( uint i = 1; i < region->req(); i++ ) {
1.25 + for (uint i = 1; i < region->req(); i++) {
1.26 Node *x;
1.27 Node* the_clone = NULL;
1.28 - if( region->in(i) == C->top() ) {
1.29 + if (region->in(i) == C->top()) {
1.30 x = C->top(); // Dead path? Use a dead data op
1.31 } else {
1.32 x = n->clone(); // Else clone up the data op
1.33 the_clone = x; // Remember for possible deletion.
1.34 // Alter data node to use pre-phi inputs
1.35 - if( n->in(0) == region )
1.36 + if (n->in(0) == region)
1.37 x->set_req( 0, region->in(i) );
1.38 - for( uint j = 1; j < n->req(); j++ ) {
1.39 + for (uint j = 1; j < n->req(); j++) {
1.40 Node *in = n->in(j);
1.41 - if( in->is_Phi() && in->in(0) == region )
1.42 + if (in->is_Phi() && in->in(0) == region)
1.43 x->set_req( j, in->in(i) ); // Use pre-Phi input for the clone
1.44 }
1.45 }
1.46 @@ -85,7 +85,7 @@
1.47 // happen if the singleton occurs on loop entry, as the elimination of
1.48 // the PhiNode may cause the resulting node to migrate back to a previous
1.49 // loop iteration.
1.50 - if( singleton && t == Type::TOP ) {
1.51 + if (singleton && t == Type::TOP) {
1.52 // Is_Loop() == false does not confirm the absence of a loop (e.g., an
1.53 // irreducible loop may not be indicated by an affirmative is_Loop());
1.54 // therefore, the only top we can split thru a phi is on a backedge of
1.55 @@ -93,7 +93,7 @@
1.56 singleton &= region->is_Loop() && (i != LoopNode::EntryControl);
1.57 }
1.58
1.59 - if( singleton ) {
1.60 + if (singleton) {
1.61 wins++;
1.62 x = ((PhaseGVN&)_igvn).makecon(t);
1.63 } else {
1.64 @@ -108,12 +108,12 @@
1.65 // igvn->type(x) is set to x->Value() already.
1.66 x->raise_bottom_type(t);
1.67 Node *y = x->Identity(&_igvn);
1.68 - if( y != x ) {
1.69 + if (y != x) {
1.70 wins++;
1.71 x = y;
1.72 } else {
1.73 y = _igvn.hash_find(x);
1.74 - if( y ) {
1.75 + if (y) {
1.76 wins++;
1.77 x = y;
1.78 } else {
1.79 @@ -129,7 +129,7 @@
1.80 phi->set_req( i, x );
1.81 }
1.82 // Too few wins?
1.83 - if( wins <= policy ) {
1.84 + if (wins <= policy) {
1.85 _igvn.remove_dead_node(phi);
1.86 return NULL;
1.87 }
1.88 @@ -137,7 +137,7 @@
1.89 // Record Phi
1.90 register_new_node( phi, region );
1.91
1.92 - for( uint i2 = 1; i2 < phi->req(); i2++ ) {
1.93 + for (uint i2 = 1; i2 < phi->req(); i2++) {
1.94 Node *x = phi->in(i2);
1.95 // If we commoned up the cloned 'x' with another existing Node,
1.96 // the existing Node picks up a new use. We need to make the
1.97 @@ -145,24 +145,44 @@
1.98 Node *old_ctrl;
1.99 IdealLoopTree *old_loop;
1.100
1.101 + if (x->is_Con()) {
1.102 + // Constant's control is always root.
1.103 + set_ctrl(x, C->root());
1.104 + continue;
1.105 + }
1.106 // The occasional new node
1.107 - if( x->_idx >= old_unique ) { // Found a new, unplaced node?
1.108 - old_ctrl = x->is_Con() ? C->root() : NULL;
1.109 - old_loop = NULL; // Not in any prior loop
1.110 + if (x->_idx >= old_unique) { // Found a new, unplaced node?
1.111 + old_ctrl = NULL;
1.112 + old_loop = NULL; // Not in any prior loop
1.113 } else {
1.114 - old_ctrl = x->is_Con() ? C->root() : get_ctrl(x);
1.115 + old_ctrl = get_ctrl(x);
1.116 old_loop = get_loop(old_ctrl); // Get prior loop
1.117 }
1.118 // New late point must dominate new use
1.119 - Node *new_ctrl = dom_lca( old_ctrl, region->in(i2) );
1.120 + Node *new_ctrl = dom_lca(old_ctrl, region->in(i2));
1.121 + if (new_ctrl == old_ctrl) // Nothing is changed
1.122 + continue;
1.123 +
1.124 + IdealLoopTree *new_loop = get_loop(new_ctrl);
1.125 +
1.126 + // Don't move x into a loop if its uses are
1.127 + // outside of loop. Otherwise x will be cloned
1.128 + // for each use outside of this loop.
1.129 + IdealLoopTree *use_loop = get_loop(region);
1.130 + if (!new_loop->is_member(use_loop) &&
1.131 + (old_loop == NULL || !new_loop->is_member(old_loop))) {
1.132 + // Take early control, later control will be recalculated
1.133 + // during next iteration of loop optimizations.
1.134 + new_ctrl = get_early_ctrl(x);
1.135 + new_loop = get_loop(new_ctrl);
1.136 + }
1.137 // Set new location
1.138 set_ctrl(x, new_ctrl);
1.139 - IdealLoopTree *new_loop = get_loop( new_ctrl );
1.140 // If changing loop bodies, see if we need to collect into new body
1.141 - if( old_loop != new_loop ) {
1.142 - if( old_loop && !old_loop->_child )
1.143 + if (old_loop != new_loop) {
1.144 + if (old_loop && !old_loop->_child)
1.145 old_loop->_body.yank(x);
1.146 - if( !new_loop->_child )
1.147 + if (!new_loop->_child)
1.148 new_loop->_body.push(x); // Collect body info
1.149 }
1.150 }
1.151 @@ -174,9 +194,9 @@
1.152 // Replace the dominated test with an obvious true or false. Place it on the
1.153 // IGVN worklist for later cleanup. Move control-dependent data Nodes on the
1.154 // live path up to the dominating control.
1.155 -void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff ) {
1.156 +void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff, bool flip ) {
1.157 #ifndef PRODUCT
1.158 - if( VerifyLoopOptimizations && PrintOpto ) tty->print_cr("dominating test");
1.159 + if (VerifyLoopOptimizations && PrintOpto) tty->print_cr("dominating test");
1.160 #endif
1.161
1.162
1.163 @@ -185,6 +205,12 @@
1.164 assert( iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd, "Check this code when new subtype is added");
1.165 int pop = prevdom->Opcode();
1.166 assert( pop == Op_IfFalse || pop == Op_IfTrue, "" );
1.167 + if (flip) {
1.168 + if (pop == Op_IfTrue)
1.169 + pop = Op_IfFalse;
1.170 + else
1.171 + pop = Op_IfTrue;
1.172 + }
1.173 // 'con' is set to true or false to kill the dominated test.
1.174 Node *con = _igvn.makecon(pop == Op_IfTrue ? TypeInt::ONE : TypeInt::ZERO);
1.175 set_ctrl(con, C->root()); // Constant gets a new use
1.176 @@ -197,7 +223,7 @@
1.177 // I can assume this path reaches an infinite loop. In this case it's not
1.178 // important to optimize the data Nodes - either the whole compilation will
1.179 // be tossed or this path (and all data Nodes) will go dead.
1.180 - if( iff->outcnt() != 2 ) return;
1.181 + if (iff->outcnt() != 2) return;
1.182
1.183 // Make control-dependent data Nodes on the live path (path that will remain
1.184 // once the dominated IF is removed) become control-dependent on the
1.185 @@ -207,16 +233,16 @@
1.186
1.187 for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) {
1.188 Node* cd = dp->fast_out(i); // Control-dependent node
1.189 - if( cd->depends_only_on_test() ) {
1.190 - assert( cd->in(0) == dp, "" );
1.191 - _igvn.hash_delete( cd );
1.192 + if (cd->depends_only_on_test()) {
1.193 + assert(cd->in(0) == dp, "");
1.194 + _igvn.hash_delete(cd);
1.195 cd->set_req(0, prevdom);
1.196 - set_early_ctrl( cd );
1.197 + set_early_ctrl(cd);
1.198 _igvn._worklist.push(cd);
1.199 IdealLoopTree *new_loop = get_loop(get_ctrl(cd));
1.200 - if( old_loop != new_loop ) {
1.201 - if( !old_loop->_child ) old_loop->_body.yank(cd);
1.202 - if( !new_loop->_child ) new_loop->_body.push(cd);
1.203 + if (old_loop != new_loop) {
1.204 + if (!old_loop->_child) old_loop->_body.yank(cd);
1.205 + if (!new_loop->_child) new_loop->_body.push(cd);
1.206 }
1.207 --i;
1.208 --imax;
1.209 @@ -2338,6 +2364,11 @@
1.210 }
1.211
1.212 #if !defined(PRODUCT)
1.213 + if (TraceLoopOpts) {
1.214 + tty->print("PartialPeel ");
1.215 + loop->dump_head();
1.216 + }
1.217 +
1.218 if (TracePartialPeeling) {
1.219 tty->print_cr("before partial peel one iteration");
1.220 Node_List wl;
1.221 @@ -2481,6 +2512,7 @@
1.222 // Create new loop head for new phis and to hang
1.223 // the nodes being moved (sinked) from the peel region.
1.224 LoopNode* new_head = new (C, 3) LoopNode(last_peel, last_peel);
1.225 + new_head->set_unswitch_count(head->unswitch_count()); // Preserve
1.226 _igvn.register_new_node_with_optimizer(new_head);
1.227 assert(first_not_peeled->in(0) == last_peel, "last_peel <- first_not_peeled");
1.228 first_not_peeled->set_req(0, new_head);
1.229 @@ -2651,24 +2683,23 @@
1.230 // prevent loop-fallout uses of the pre-incremented trip counter (which are
1.231 // then alive with the post-incremented trip counter forcing an extra
1.232 // register move)
1.233 -void PhaseIdealLoop::reorg_offsets( IdealLoopTree *loop ) {
1.234 +void PhaseIdealLoop::reorg_offsets(IdealLoopTree *loop) {
1.235 + // Perform it only for canonical counted loops.
1.236 + // Loop's shape could be messed up by iteration_split_impl.
1.237 + if (!loop->_head->is_CountedLoop())
1.238 + return;
1.239 + if (!loop->_head->as_Loop()->is_valid_counted_loop())
1.240 + return;
1.241
1.242 CountedLoopNode *cl = loop->_head->as_CountedLoop();
1.243 CountedLoopEndNode *cle = cl->loopexit();
1.244 - if( !cle ) return; // The occasional dead loop
1.245 - // Find loop exit control
1.246 Node *exit = cle->proj_out(false);
1.247 - assert( exit->Opcode() == Op_IfFalse, "" );
1.248 + Node *phi = cl->phi();
1.249
1.250 // Check for the special case of folks using the pre-incremented
1.251 // trip-counter on the fall-out path (forces the pre-incremented
1.252 // and post-incremented trip counter to be live at the same time).
1.253 // Fix this by adjusting to use the post-increment trip counter.
1.254 - Node *phi = cl->phi();
1.255 - if( !phi ) return; // Dead infinite loop
1.256 -
1.257 - // Shape messed up, probably by iteration_split_impl
1.258 - if (phi->in(LoopNode::LoopBackControl) != cl->incr()) return;
1.259
1.260 bool progress = true;
1.261 while (progress) {
1.262 @@ -2677,21 +2708,19 @@
1.263 Node* use = phi->fast_out(i); // User of trip-counter
1.264 if (!has_ctrl(use)) continue;
1.265 Node *u_ctrl = get_ctrl(use);
1.266 - if( use->is_Phi() ) {
1.267 + if (use->is_Phi()) {
1.268 u_ctrl = NULL;
1.269 - for( uint j = 1; j < use->req(); j++ )
1.270 - if( use->in(j) == phi )
1.271 - u_ctrl = dom_lca( u_ctrl, use->in(0)->in(j) );
1.272 + for (uint j = 1; j < use->req(); j++)
1.273 + if (use->in(j) == phi)
1.274 + u_ctrl = dom_lca(u_ctrl, use->in(0)->in(j));
1.275 }
1.276 IdealLoopTree *u_loop = get_loop(u_ctrl);
1.277 // Look for loop-invariant use
1.278 - if( u_loop == loop ) continue;
1.279 - if( loop->is_member( u_loop ) ) continue;
1.280 + if (u_loop == loop) continue;
1.281 + if (loop->is_member(u_loop)) continue;
1.282 // Check that use is live out the bottom. Assuming the trip-counter
1.283 // update is right at the bottom, uses of of the loop middle are ok.
1.284 - if( dom_lca( exit, u_ctrl ) != exit ) continue;
1.285 - // protect against stride not being a constant
1.286 - if( !cle->stride_is_con() ) continue;
1.287 + if (dom_lca(exit, u_ctrl) != exit) continue;
1.288 // Hit! Refactor use to use the post-incremented tripcounter.
1.289 // Compute a post-increment tripcounter.
1.290 Node *opaq = new (C, 2) Opaque2Node( C, cle->incr() );
1.291 @@ -2702,9 +2731,10 @@
1.292 register_new_node( post, u_ctrl );
1.293 _igvn.hash_delete(use);
1.294 _igvn._worklist.push(use);
1.295 - for( uint j = 1; j < use->req(); j++ )
1.296 - if( use->in(j) == phi )
1.297 + for (uint j = 1; j < use->req(); j++) {
1.298 + if (use->in(j) == phi)
1.299 use->set_req(j, post);
1.300 + }
1.301 // Since DU info changed, rerun loop
1.302 progress = true;
1.303 break;
