truffle: src/share/vm/opto/superword.cpp comparison

comparison src/share/vm/opto/superword.cpp @ 667:78af5ae8e731

6636138: UseSuperWord enabled failure Summary: Fixed SuperWord scheduling of memory operations. Reviewed-by: kvn, never

author	cfang
date	Tue, 24 Mar 2009 12:19:47 -0700
parents	7bb995fbd3c0
children	ace8397c8563

comparison

equal deleted inserted replaced

-:ebebd376f657
+:78af5ae8e731
 if (out->is_MergeMem() && !in_bb(out)) {
 // Either unrolling is causing a memory edge not to disappear,
 // or need to run igvn.optimize() again before SLP
 } else if (out->is_Phi() && out->bottom_type() == Type::MEMORY && !in_bb(out)) {
 // Ditto.  Not sure what else to check further.
-} else if (out->Opcode() == Op_StoreCM && out->in(4) == n) {
+} else if (out->Opcode() == Op_StoreCM && out->in(MemNode::OopStore) == n) {
 // StoreCM has an input edge used as a precedence edge.
 // Maybe an issue when oop stores are vectorized.
+} else if( out->is_MergeMem() && prev &&
+prev->Opcode() == Op_StoreCM && out == prev->in(MemNode::OopStore)) {
+// Oop store is a MergeMem! This should not happen. Temporarily remove the assertion
+// for this case because it could not be superwordized anyway.
 } else {
 assert(out == prev || prev == NULL, "no branches off of store slice");
 }
 }
 }
 for (int i = 0; i < _packset.length(); i++) {
 co_locate_pack(_packset.at(i));
 }
 }
-//------------------------------co_locate_pack---------------------------
+//-------------------------------remove_and_insert-------------------
-// Within a pack, move stores down to the last executed store,
+//remove "current" from its current position in the memory graph and insert
-// and move loads up to the first executed load.
+//it after the appropriate insertion point (lip or uip)
+void SuperWord::remove_and_insert(MemNode *current, MemNode *prev, MemNode *lip,
+Node *uip, Unique_Node_List &sched_before) {
+Node* my_mem = current->in(MemNode::Memory);
+_igvn.hash_delete(current);
+_igvn.hash_delete(my_mem);
+//remove current_store from its current position in the memmory graph
+for (DUIterator i = current->outs(); current->has_out(i); i++) {
+Node* use = current->out(i);
+if (use->is_Mem()) {
+assert(use->in(MemNode::Memory) == current, "must be");
+_igvn.hash_delete(use);
+if (use == prev) { // connect prev to my_mem
+use->set_req(MemNode::Memory, my_mem);
+} else if (sched_before.member(use)) {
+_igvn.hash_delete(uip);
+use->set_req(MemNode::Memory, uip);
+} else {
+_igvn.hash_delete(lip);
+use->set_req(MemNode::Memory, lip);
+}
+_igvn._worklist.push(use);
+--i; //deleted this edge; rescan position
+}
+}
+bool sched_up = sched_before.member(current);
+Node *insert_pt =  sched_up ?  uip : lip;
+_igvn.hash_delete(insert_pt);
+// all uses of insert_pt's memory state should use current's instead
+for (DUIterator i = insert_pt->outs(); insert_pt->has_out(i); i++) {
+Node* use = insert_pt->out(i);
+if (use->is_Mem()) {
+assert(use->in(MemNode::Memory) == insert_pt, "must be");
+_igvn.hash_delete(use);
+use->set_req(MemNode::Memory, current);
+_igvn._worklist.push(use);
+--i; //deleted this edge; rescan position
+} else if (!sched_up && use->is_Phi() && use->bottom_type() == Type::MEMORY) {
+uint pos; //lip (lower insert point) must be the last one in the memory slice
+_igvn.hash_delete(use);
+for (pos=1; pos < use->req(); pos++) {
+if (use->in(pos) == insert_pt) break;
+}
+use->set_req(pos, current);
+_igvn._worklist.push(use);
+--i;
+}
+}
+//connect current to insert_pt
+current->set_req(MemNode::Memory, insert_pt);
+_igvn._worklist.push(current);
+}
+//------------------------------co_locate_pack----------------------------------
+// To schedule a store pack, we need to move any sandwiched memory ops either before
+// or after the pack, based upon dependence information:
+// (1) If any store in the pack depends on the sandwiched memory op, the
+//     sandwiched memory op must be scheduled BEFORE the pack;
+// (2) If a sandwiched memory op depends on any store in the pack, the
+//     sandwiched memory op must be scheduled AFTER the pack;
+// (3) If a sandwiched memory op (say, memA) depends on another sandwiched
+//     memory op (say memB), memB must be scheduled before memA. So, if memA is
+//     scheduled before the pack, memB must also be scheduled before the pack;
+// (4) If there is no dependence restriction for a sandwiched memory op, we simply
+//     schedule this store AFTER the pack
+// (5) We know there is no dependence cycle, so there in no other case;
+// (6) Finally, all memory ops in another single pack should be moved in the same direction.
+//
+// To schedule a load pack: the memory edge of every loads in the pack must be
+// the same as the memory edge of the last executed load in the pack
 void SuperWord::co_locate_pack(Node_List* pk) {
 if (pk->at(0)->is_Store()) {
-// Push Stores down towards last executed pack member
 MemNode* first     = executed_first(pk)->as_Mem();
 MemNode* last      = executed_last(pk)->as_Mem();
-MemNode* insert_pt = last;
+Unique_Node_List schedule_before_pack;
+Unique_Node_List memops;
 MemNode* current   = last->in(MemNode::Memory)->as_Mem();
+MemNode* previous  = last;
 while (true) {
 assert(in_bb(current), "stay in block");
+memops.push(previous);
+for (DUIterator i = current->outs(); current->has_out(i); i++) {
+Node* use = current->out(i);
+if (use->is_Mem() && use != previous)
+memops.push(use);
+}
+if(current == first) break;
+previous = current;
+current  = current->in(MemNode::Memory)->as_Mem();
+}
+// determine which memory operations should be scheduled before the pack
+for (uint i = 1; i < memops.size(); i++) {
+Node *s1 = memops.at(i);
+if (!in_pack(s1, pk) && !schedule_before_pack.member(s1)) {
+for (uint j = 0; j< i; j++) {
+Node *s2 = memops.at(j);
+if (!independent(s1, s2)) {
+if (in_pack(s2, pk) || schedule_before_pack.member(s2)) {
+schedule_before_pack.push(s1); //s1 must be scheduled before
+Node_List* mem_pk = my_pack(s1);
+if (mem_pk != NULL) {
+for (uint ii = 0; ii < mem_pk->size(); ii++) {
+Node* s = mem_pk->at(ii); // follow partner
+if (memops.member(s) && !schedule_before_pack.member(s))
+schedule_before_pack.push(s);
+}
+}
+}
+}
+}
+}
+}
+MemNode* lower_insert_pt = last;
+Node*    upper_insert_pt = first->in(MemNode::Memory);
+previous                 = last; //previous store in pk
+current                  = last->in(MemNode::Memory)->as_Mem();
+//start scheduling from "last" to "first"
+while (true) {
+assert(in_bb(current), "stay in block");
+assert(in_pack(previous, pk), "previous stays in pack");
 Node* my_mem = current->in(MemNode::Memory);
 if (in_pack(current, pk)) {
-// Forward users of my memory state to my input memory state
+// Forward users of my memory state (except "previous) to my input memory state
 _igvn.hash_delete(current);
-_igvn.hash_delete(my_mem);
 for (DUIterator i = current->outs(); current->has_out(i); i++) {
 Node* use = current->out(i);
-if (use->is_Mem()) {
+if (use->is_Mem() && use != previous) {
 assert(use->in(MemNode::Memory) == current, "must be");
 _igvn.hash_delete(use);
-use->set_req(MemNode::Memory, my_mem);
+if (schedule_before_pack.member(use)) {
+_igvn.hash_delete(upper_insert_pt);
+use->set_req(MemNode::Memory, upper_insert_pt);
+} else {
+_igvn.hash_delete(lower_insert_pt);
+use->set_req(MemNode::Memory, lower_insert_pt);
+}
 _igvn._worklist.push(use);
 --i; // deleted this edge; rescan position
 }
 }
-// put current immediately before insert_pt
+previous = current;
-current->set_req(MemNode::Memory, insert_pt->in(MemNode::Memory));
+} else { // !in_pack(current, pk) ==> a sandwiched store
-_igvn.hash_delete(insert_pt);
+remove_and_insert(current, previous, lower_insert_pt, upper_insert_pt, schedule_before_pack);
-insert_pt->set_req(MemNode::Memory, current);
+}
-_igvn._worklist.push(insert_pt);
-_igvn._worklist.push(current);
-insert_pt = current;
-}
 if (current == first) break;
 current = my_mem->as_Mem();
-}
+} // end while
-} else if (pk->at(0)->is_Load()) {
+} else if (pk->at(0)->is_Load()) { //load
-// Pull Loads up towards first executed pack member
+// all use the memory state that the last executed load uses
-LoadNode* first = executed_first(pk)->as_Load();
+LoadNode* last_load  = executed_last(pk)->as_Load();
-Node* first_mem = first->in(MemNode::Memory);
+Node* last_mem       = last_load->in(MemNode::Memory);
-_igvn.hash_delete(first_mem);
+_igvn.hash_delete(last_mem);
-// Give each load same memory state as first
+// Give each load same memory state as last
 for (uint i = 0; i < pk->size(); i++) {
 LoadNode* ld = pk->at(i)->as_Load();
 _igvn.hash_delete(ld);
-ld->set_req(MemNode::Memory, first_mem);
+ld->set_req(MemNode::Memory, last_mem);
 _igvn._worklist.push(ld);
 }
 }
 }

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comparison src/share/vm/opto/superword.cpp @ 667:78af5ae8e731