Cleanup how we handle side effects in HInstruction and put the right flags for HIs, modulo, truncat…

sdk/lib/_internal/compiler/implementation/ssa/optimize.dart

 // 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.
 
 part of ssa;
 
 abstract class OptimizationPhase {
   String get name;
   void visitGraph(HGraph graph);
 }
@@ skipping 784 matching lines @@
 
   bool isDeadCode(HInstruction instruction) {
     return !instruction.hasSideEffects()
            && instruction.usedBy.isEmpty
            // A dynamic getter that has no side effect can still throw
            // a NoSuchMethodError.
            && instruction is !HInvokeDynamicGetter
            && instruction is !HCheck
            && instruction is !HTypeGuard
            && instruction is !HParameterValue
+           && instruction is !HLocalSet
            && !instruction.isControlFlow();
   }
 
   void visitGraph(HGraph graph) {
     visitPostDominatorTree(graph);
   }
 
   void visitBasicBlock(HBasicBlock block) {
     HInstruction instruction = block.last;
     while (instruction != null) {
@@ skipping 240 matching lines @@
     // Run through all the basic blocks in the graph and fill in the
     // changes flags lists.
     for (int i = length - 1; i >= 0; i--) {
       final HBasicBlock block = graph.blocks[i];
       final int id = block.id;
 
       // Compute block changes flags for the block.
       int changesFlags = 0;
       HInstruction instruction = block.first;
       while (instruction != null) {
-        instruction.prepareGvn(types);
         changesFlags |= instruction.getChangesFlags();
         instruction = instruction.next;
       }
       assert(blockChangesFlags[id] == null);
       blockChangesFlags[id] = changesFlags;
 
       // Loop headers are part of their loop, so update the loop
       // changes flags accordingly.
       if (block.isLoopHeader()) {
         loopChangesFlags[id] |= changesFlags;
@@ skipping 365 matching lines @@
             || otherIntercepted.contains(backend.jsDoubleClass)) {
           interceptor.interceptedClasses.addAll(user.interceptedClasses);
         }
         user.interceptedClasses = interceptor.interceptedClasses;
       }
     }
   }
 
   // TODO(ngeoffray): Also implement it for non-intercepted calls.
 }