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

runtime/vm/constant_propagator.cc

 // Copyright (c) 2013, 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/constant_propagator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_range_analysis.h"
@@ skipping 1360 matching lines @@
 
 void ConstantPropagator::EliminateRedundantBranches() {
   // Canonicalize branches that have no side-effects and where true- and
   // false-targets are the same.
   bool changed = false;
   BitVector* empty_blocks = new (Z) BitVector(Z, graph_->preorder().length());
   for (BlockIterator b = graph_->postorder_iterator(); !b.Done(); b.Advance()) {
     BlockEntryInstr* block = b.Current();
     BranchInstr* branch = block->last_instruction()->AsBranch();
     empty_blocks->Clear();
-    if ((branch != NULL) && branch->Effects().IsNone()) {
+    if ((branch != NULL) && !branch->HasUnknownSideEffects()) {
       ASSERT(branch->previous() != NULL);  // Not already eliminated.
       BlockEntryInstr* if_true =
           FindFirstNonEmptySuccessor(branch->true_successor(), empty_blocks);
       BlockEntryInstr* if_false =
           FindFirstNonEmptySuccessor(branch->false_successor(), empty_blocks);
       if (if_true == if_false) {
         // Replace the branch with a jump to the common successor.
         // Drop the comparison, which does not have side effects
         JoinEntryInstr* join = if_true->AsJoinEntry();
         if (join->phis() == NULL) {
@@ skipping 180 matching lines @@
   GrowableArray<BitVector*> dominance_frontier;
   graph_->ComputeDominators(&dominance_frontier);
 
   if (FLAG_trace_constant_propagation &&
       FlowGraphPrinter::ShouldPrint(graph_->function())) {
     FlowGraphPrinter::PrintGraph("After CP", graph_);
   }
 }
 
 }  // namespace dart