[vm] Cleanup Instruction::Effects(), prepare to cleanup Dependencies()

runtime/vm/flow_graph.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 1424 matching lines @@
   GrowableArray<BitVector*> available_after(block_count);
 
   // Discover all blocks with side-effects.
   for (BlockIterator it = flow_graph->postorder_iterator(); !it.Done();
        it.Advance()) {
     available_at_.Add(NULL);
     available_after.Add(NULL);
 
     BlockEntryInstr* block = it.Current();
     for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
-      if (!it.Current()->Effects().IsNone()) {
+      if (it.Current()->HasUnknownSideEffects()) {
         kill->Add(block->postorder_number());
         break;
       }
     }
   }
 
   BitVector* temp = new (zone) BitVector(zone, block_count);
 
   // Recompute available-at based on predecessors' available-after until the fix
   // point is reached.
@@ skipping 37 matching lines @@
           available_after[block_num]->Add(block_num);
         }
         changed = true;
       }
     }
   } while (changed);
 }
 
 bool BlockEffects::IsAvailableAt(Instruction* instr,
                                  BlockEntryInstr* block) const {
-  return (instr->Dependencies().IsNone()) ||
-         IsSideEffectFreePath(instr->GetBlock(), block);
+  ASSERT(instr->AllowsCSE());
+  ASSERT(instr->Dependencies().IsNone());
+  return true;  // TODO(dartbug.com/30474): cleanup
 }
 
 bool BlockEffects::CanBeMovedTo(Instruction* instr,
                                 BlockEntryInstr* block) const {
-  return (instr->Dependencies().IsNone()) ||
-         IsSideEffectFreePath(block, instr->GetBlock());
+  ASSERT(instr->AllowsCSE());
+  ASSERT(instr->Dependencies().IsNone());
+  return true;  // TODO(dartbug.com/30474): cleanup
 }
 
 bool BlockEffects::IsSideEffectFreePath(BlockEntryInstr* from,
                                         BlockEntryInstr* to) const {
   return available_at_[to->postorder_number()]->Contains(
       from->postorder_number());
 }
 
 // Quick access to the current zone.
 #define Z (zone())
@@ skipping 743 matching lines @@
                                                 intptr_t index,
                                                 Representation rep,
                                                 intptr_t cid) {
   ExtractNthOutputInstr* extract =
       new (Z) ExtractNthOutputInstr(new (Z) Value(instr), index, rep, cid);
   instr->ReplaceUsesWith(extract);
   InsertAfter(instr, extract, NULL, FlowGraph::kValue);
 }
 
 }  // namespace dart