Revert "ART: Implement DeadPhiHandling in PrimitiveTypePropagation"

Crashes on YouTube, need to investigate

This reverts commit 1749e2cfb5c5ed4d6970a09aecf898ca9cdfcb75.

Change-Id: If5f133d55dcc26b8db79a670a48fbd4af7807556
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 1995797..0f2c1cf 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -4238,7 +4238,7 @@
         inputs_(number_of_inputs, arena->Adapter(kArenaAllocPhiInputs)),
         reg_number_(reg_number),
         type_(type),
-        is_live_(true),
+        is_live_(false),
         can_be_null_(true) {
   }
 
@@ -4263,18 +4263,7 @@
   void RemoveInputAt(size_t index);
 
   Primitive::Type GetType() const OVERRIDE { return type_; }
-  void SetType(Primitive::Type new_type) {
-    // Make sure that only valid type changes occur. The following are allowed:
-    //  (1) void -> * (initial type assignment),
-    //  (2) int  -> float/ref (primitive type propagation),
-    //  (3) long -> double (primitive type propagation).
-    DCHECK(type_ == new_type ||
-           type_ == Primitive::kPrimVoid ||
-           (type_ == Primitive::kPrimInt && new_type == Primitive::kPrimFloat) ||
-           (type_ == Primitive::kPrimInt && new_type == Primitive::kPrimNot) ||
-           (type_ == Primitive::kPrimLong && new_type == Primitive::kPrimDouble));
-    type_ = new_type;
-  }
+  void SetType(Primitive::Type type) { type_ = type; }
 
   bool CanBeNull() const OVERRIDE { return can_be_null_; }
   void SetCanBeNull(bool can_be_null) { can_be_null_ = can_be_null; }
@@ -4496,8 +4485,7 @@
             SideEffects additional_side_effects = SideEffects::None())
       : HExpression(type,
                     SideEffects::ArrayReadOfType(type).Union(additional_side_effects),
-                    dex_pc),
-        fixed_type_(type != Primitive::kPrimInt && type != Primitive::kPrimLong) {
+                    dex_pc) {
     SetRawInputAt(0, array);
     SetRawInputAt(1, index);
   }
@@ -4515,13 +4503,7 @@
     return false;
   }
 
-  void SetType(Primitive::Type type) {
-    DCHECK(type_ == type || !IsTypeFixed());
-    type_ = type;
-  }
-
-  bool IsTypeFixed() const { return fixed_type_; }
-  void FixType() { fixed_type_ = true; }
+  void SetType(Primitive::Type type) { type_ = type; }
 
   HInstruction* GetArray() const { return InputAt(0); }
   HInstruction* GetIndex() const { return InputAt(1); }
@@ -4529,12 +4511,6 @@
   DECLARE_INSTRUCTION(ArrayGet);
 
  private:
-  // Bytecode aget(-wide) instructions have ambiguous type (int/float, long/double).
-  // If the type can be determined from uses, `fixed_type_` should be set to true,
-  // to prevent PrimitiveTypePropagation from changing it while typing phis. With
-  // other aget-* variants, the type is always unambiguous.
-  bool fixed_type_;
-
   DISALLOW_COPY_AND_ASSIGN(HArrayGet);
 };
 
diff --git a/compiler/optimizing/primitive_type_propagation.cc b/compiler/optimizing/primitive_type_propagation.cc
index c38f466..c98f43e 100644
--- a/compiler/optimizing/primitive_type_propagation.cc
+++ b/compiler/optimizing/primitive_type_propagation.cc
@@ -21,120 +21,60 @@
 
 namespace art {
 
-bool PrimitiveTypePropagation::TypePhiFromInputs(HPhi* phi) {
-  Primitive::Type common_type = phi->GetType();
-
-  for (HInputIterator it(phi); !it.Done(); it.Advance()) {
-    HInstruction* input = it.Current();
-    if (input->IsPhi() && input->AsPhi()->IsDead()) {
-      // Phis are constructed live so if an input is a dead phi, it must have
-      // been made dead due to type conflict. Mark this phi conflicting too.
-      return false;
-    }
-
-    Primitive::Type input_type = HPhi::ToPhiType(input->GetType());
-    if (common_type == Primitive::kPrimVoid) {
-      // Setting type for the first time.
-      common_type = input_type;
-    } else if (common_type == input_type) {
-      // No change in type.
-    } else if (input_type == Primitive::kPrimVoid) {
-      // Input is a phi which has not been typed yet. Do nothing.
-      DCHECK(input->IsPhi());
-    } else if (Primitive::ComponentSize(common_type) != Primitive::ComponentSize(input_type)) {
-      // Types are of different sizes, e.g. int vs. long. Must be a conflict.
-      return false;
-    } else if (Primitive::IsIntegralType(common_type)) {
-      // Previous inputs were integral, this one is not but is of the same size.
-      // This does not imply conflict since some bytecode instruction types are
-      // ambiguous. TypeInputsOfPhi will either type them or detect a conflict.
-      DCHECK(Primitive::IsFloatingPointType(input_type) || input_type == Primitive::kPrimNot);
-      common_type = input_type;
-    } else if (Primitive::IsIntegralType(input_type)) {
-      // Input is integral, common type is not. Same as in the previous case, if
-      // there is a conflict, it will be detected during TypeInputsOfPhi.
-      DCHECK(Primitive::IsFloatingPointType(common_type) || common_type == Primitive::kPrimNot);
-    } else {
-      // Combining float and reference types. Clearly a conflict.
-      DCHECK((common_type == Primitive::kPrimFloat && input_type == Primitive::kPrimNot) ||
-             (common_type == Primitive::kPrimNot && input_type == Primitive::kPrimFloat));
-      return false;
-    }
+static Primitive::Type MergeTypes(Primitive::Type existing, Primitive::Type new_type) {
+  // We trust the verifier has already done the necessary checking.
+  switch (existing) {
+    case Primitive::kPrimFloat:
+    case Primitive::kPrimDouble:
+    case Primitive::kPrimNot:
+      return existing;
+    default:
+      // Phis are initialized with a void type, so if we are asked
+      // to merge with a void type, we should use the existing one.
+      return new_type == Primitive::kPrimVoid
+          ? existing
+          : HPhi::ToPhiType(new_type);
   }
-
-  // We have found a candidate type for the phi. Set it and return true. We may
-  // still discover conflict whilst typing the individual inputs in TypeInputsOfPhi.
-  phi->SetType(common_type);
-  return true;
 }
 
-bool PrimitiveTypePropagation::TypeInputsOfPhi(HPhi* phi) {
-  Primitive::Type common_type = phi->GetType();
-  if (common_type == Primitive::kPrimVoid || Primitive::IsIntegralType(common_type)) {
-    // Phi either contains only other untyped phis (common_type == kPrimVoid),
-    // or `common_type` is integral and we do not need to retype ambiguous inputs
-    // because they are always constructed with the integral type candidate.
-    if (kIsDebugBuild) {
-      for (size_t i = 0, e = phi->InputCount(); i < e; ++i) {
-        HInstruction* input = phi->InputAt(i);
-        if (common_type == Primitive::kPrimVoid) {
-          DCHECK(input->IsPhi() && input->GetType() == Primitive::kPrimVoid);
-        } else {
-          DCHECK((input->IsPhi() && input->GetType() == Primitive::kPrimVoid) ||
-                 HPhi::ToPhiType(input->GetType()) == common_type);
-        }
-      }
-    }
-    // Inputs did not need to be replaced, hence no conflict. Report success.
-    return true;
-  } else {
-    DCHECK(common_type == Primitive::kPrimNot || Primitive::IsFloatingPointType(common_type));
+// Re-compute and update the type of the instruction. Returns
+// whether or not the type was changed.
+bool PrimitiveTypePropagation::UpdateType(HPhi* phi) {
+  DCHECK(phi->IsLive());
+  Primitive::Type existing = phi->GetType();
+
+  Primitive::Type new_type = existing;
+  for (size_t i = 0, e = phi->InputCount(); i < e; ++i) {
+    Primitive::Type input_type = phi->InputAt(i)->GetType();
+    new_type = MergeTypes(new_type, input_type);
+  }
+  phi->SetType(new_type);
+
+  if (new_type == Primitive::kPrimDouble
+      || new_type == Primitive::kPrimFloat
+      || new_type == Primitive::kPrimNot) {
+    // If the phi is of floating point type, we need to update its inputs to that
+    // type. For inputs that are phis, we need to recompute their types.
     for (size_t i = 0, e = phi->InputCount(); i < e; ++i) {
       HInstruction* input = phi->InputAt(i);
-      if (input->GetType() != common_type) {
-        // Input type does not match phi's type. Try to retype the input or
-        // generate a suitably typed equivalent.
-        HInstruction* equivalent = (common_type == Primitive::kPrimNot)
+      if (input->GetType() != new_type) {
+        HInstruction* equivalent = (new_type == Primitive::kPrimNot)
             ? SsaBuilder::GetReferenceTypeEquivalent(input)
-            : SsaBuilder::GetFloatOrDoubleEquivalent(phi, input, common_type);
-        if (equivalent == nullptr) {
-          // Input could not be typed. Report conflict.
-          return false;
-        }
-
+            : SsaBuilder::GetFloatOrDoubleEquivalent(phi, input, new_type);
         phi->ReplaceInput(equivalent, i);
         if (equivalent->IsPhi()) {
+          equivalent->AsPhi()->SetLive();
           AddToWorklist(equivalent->AsPhi());
         } else if (equivalent == input) {
           // The input has changed its type. It can be an input of other phis,
           // so we need to put phi users in the work list.
-          AddDependentInstructionsToWorklist(input);
+          AddDependentInstructionsToWorklist(equivalent);
         }
       }
     }
-    // All inputs either matched the type of the phi or we successfully replaced
-    // them with a suitable equivalent. Report success.
-    return true;
-  }
-}
-
-bool PrimitiveTypePropagation::UpdateType(HPhi* phi) {
-  DCHECK(phi->IsLive());
-  Primitive::Type original_type = phi->GetType();
-
-  // Try to type the phi in two stages:
-  // (1) find a candidate type for the phi by merging types of all its inputs,
-  // (2) try to type the phi's inputs to that candidate type.
-  // Either of these stages may detect a type conflict and fail, in which case
-  // we immediately abort.
-  if (!TypePhiFromInputs(phi) || !TypeInputsOfPhi(phi)) {
-    // Conflict detected. Mark the phi dead and return true because it changed.
-    phi->SetDead();
-    return true;
   }
 
-  // Return true if the type of the phi has changed.
-  return phi->GetType() != original_type;
+  return existing != new_type;
 }
 
 void PrimitiveTypePropagation::Run() {
@@ -169,12 +109,10 @@
 
 void PrimitiveTypePropagation::ProcessWorklist() {
   while (!worklist_.empty()) {
-    HPhi* phi = worklist_.back();
+    HPhi* instruction = worklist_.back();
     worklist_.pop_back();
-    // The phi could have been made dead as a result of conflicts while in the
-    // worklist. If it is now dead, there is no point in updating its type.
-    if (phi->IsLive() && UpdateType(phi)) {
-      AddDependentInstructionsToWorklist(phi);
+    if (UpdateType(instruction)) {
+      AddDependentInstructionsToWorklist(instruction);
     }
   }
 }
@@ -185,17 +123,10 @@
 }
 
 void PrimitiveTypePropagation::AddDependentInstructionsToWorklist(HInstruction* instruction) {
-  // If `instruction` is a dead phi, type conflict was just identified. All its
-  // live phi users, and transitively users of those users, therefore need to be
-  // marked dead/conflicting too, so we add them to the worklist. Otherwise we
-  // add users whose type does not match and needs to be updated.
-  bool add_all_live_phis = instruction->IsPhi() && instruction->AsPhi()->IsDead();
   for (HUseIterator<HInstruction*> it(instruction->GetUses()); !it.Done(); it.Advance()) {
-    HInstruction* user = it.Current()->GetUser();
-    if (user->IsPhi() && user->AsPhi()->IsLive()) {
-      if (add_all_live_phis || user->GetType() != instruction->GetType()) {
-        AddToWorklist(user->AsPhi());
-      }
+    HPhi* phi = it.Current()->GetUser()->AsPhi();
+    if (phi != nullptr && phi->IsLive() && phi->GetType() != instruction->GetType()) {
+      AddToWorklist(phi);
     }
   }
 }
diff --git a/compiler/optimizing/primitive_type_propagation.h b/compiler/optimizing/primitive_type_propagation.h
index 0b69483..212fcfc 100644
--- a/compiler/optimizing/primitive_type_propagation.h
+++ b/compiler/optimizing/primitive_type_propagation.h
@@ -38,8 +38,6 @@
   void AddToWorklist(HPhi* phi);
   void AddDependentInstructionsToWorklist(HInstruction* instruction);
   bool UpdateType(HPhi* phi);
-  bool TypePhiFromInputs(HPhi* phi);
-  bool TypeInputsOfPhi(HPhi* phi);
 
   HGraph* const graph_;
   ArenaVector<HPhi*> worklist_;
diff --git a/compiler/optimizing/ssa_builder.cc b/compiler/optimizing/ssa_builder.cc
index 20a8bdb..4565590 100644
--- a/compiler/optimizing/ssa_builder.cc
+++ b/compiler/optimizing/ssa_builder.cc
@@ -22,18 +22,204 @@
 
 namespace art {
 
-void SsaBuilder::SetLoopPhiInputs() {
-  for (HBasicBlock* block : loop_headers_) {
-    for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
-      HPhi* phi = it.Current()->AsPhi();
-      for (HBasicBlock* predecessor : block->GetPredecessors()) {
-        HInstruction* input = ValueOfLocal(predecessor, phi->GetRegNumber());
-        phi->AddInput(input);
+/**
+ * A debuggable application may require to reviving phis, to ensure their
+ * associated DEX register is available to a debugger. This class implements
+ * the logic for statement (c) of the SsaBuilder (see ssa_builder.h). It
+ * also makes sure that phis with incompatible input types are not revived
+ * (statement (b) of the SsaBuilder).
+ *
+ * This phase must be run after detecting dead phis through the
+ * DeadPhiElimination phase, and before deleting the dead phis.
+ */
+class DeadPhiHandling : public ValueObject {
+ public:
+  explicit DeadPhiHandling(HGraph* graph)
+      : graph_(graph), worklist_(graph->GetArena()->Adapter(kArenaAllocSsaBuilder)) {
+    worklist_.reserve(kDefaultWorklistSize);
+  }
+
+  void Run();
+
+ private:
+  void VisitBasicBlock(HBasicBlock* block);
+  void ProcessWorklist();
+  void AddToWorklist(HPhi* phi);
+  void AddDependentInstructionsToWorklist(HPhi* phi);
+  bool UpdateType(HPhi* phi);
+
+  HGraph* const graph_;
+  ArenaVector<HPhi*> worklist_;
+
+  static constexpr size_t kDefaultWorklistSize = 8;
+
+  DISALLOW_COPY_AND_ASSIGN(DeadPhiHandling);
+};
+
+static bool HasConflictingEquivalent(HPhi* phi) {
+  if (phi->GetNext() == nullptr) {
+    return false;
+  }
+  HPhi* next = phi->GetNext()->AsPhi();
+  if (next->GetRegNumber() == phi->GetRegNumber()) {
+    if (next->GetType() == Primitive::kPrimVoid) {
+      // We only get a void type for an equivalent phi we processed and found out
+      // it was conflicting.
+      return true;
+    } else {
+      // Go to the next phi, in case it is also an equivalent.
+      return HasConflictingEquivalent(next);
+    }
+  }
+  return false;
+}
+
+bool DeadPhiHandling::UpdateType(HPhi* phi) {
+  if (phi->IsDead()) {
+    // Phi was rendered dead while waiting in the worklist because it was replaced
+    // with an equivalent.
+    return false;
+  }
+
+  Primitive::Type existing = phi->GetType();
+
+  bool conflict = false;
+  Primitive::Type new_type = existing;
+  for (size_t i = 0, e = phi->InputCount(); i < e; ++i) {
+    HInstruction* input = phi->InputAt(i);
+    if (input->IsPhi() && input->AsPhi()->IsDead()) {
+      // We are doing a reverse post order visit of the graph, reviving
+      // phis that have environment uses and updating their types. If an
+      // input is a phi, and it is dead (because its input types are
+      // conflicting), this phi must be marked dead as well.
+      conflict = true;
+      break;
+    }
+    Primitive::Type input_type = HPhi::ToPhiType(input->GetType());
+
+    // The only acceptable transitions are:
+    // - From void to typed: first time we update the type of this phi.
+    // - From int to reference (or reference to int): the phi has to change
+    //   to reference type. If the integer input cannot be converted to a
+    //   reference input, the phi will remain dead.
+    if (new_type == Primitive::kPrimVoid) {
+      new_type = input_type;
+    } else if (new_type == Primitive::kPrimNot && input_type == Primitive::kPrimInt) {
+      if (input->IsPhi() && HasConflictingEquivalent(input->AsPhi())) {
+        // If we already asked for an equivalent of the input phi, but that equivalent
+        // ended up conflicting, make this phi conflicting too.
+        conflict = true;
+        break;
+      }
+      HInstruction* equivalent = SsaBuilder::GetReferenceTypeEquivalent(input);
+      if (equivalent == nullptr) {
+        conflict = true;
+        break;
+      }
+      phi->ReplaceInput(equivalent, i);
+      if (equivalent->IsPhi()) {
+        DCHECK_EQ(equivalent->GetType(), Primitive::kPrimNot);
+        // We created a new phi, but that phi has the same inputs as the old phi. We
+        // add it to the worklist to ensure its inputs can also be converted to reference.
+        // If not, it will remain dead, and the algorithm will make the current phi dead
+        // as well.
+        equivalent->AsPhi()->SetLive();
+        AddToWorklist(equivalent->AsPhi());
+      }
+    } else if (new_type == Primitive::kPrimInt && input_type == Primitive::kPrimNot) {
+      new_type = Primitive::kPrimNot;
+      // Start over, we may request reference equivalents for the inputs of the phi.
+      i = -1;
+    } else if (new_type != input_type) {
+      conflict = true;
+      break;
+    }
+  }
+
+  if (conflict) {
+    phi->SetType(Primitive::kPrimVoid);
+    phi->SetDead();
+    return true;
+  } else if (existing == new_type) {
+    return false;
+  }
+
+  DCHECK(phi->IsLive());
+  phi->SetType(new_type);
+
+  // There might exist a `new_type` equivalent of `phi` already. In that case,
+  // we replace the equivalent with the, now live, `phi`.
+  HPhi* equivalent = phi->GetNextEquivalentPhiWithSameType();
+  if (equivalent != nullptr) {
+    // There cannot be more than two equivalents with the same type.
+    DCHECK(equivalent->GetNextEquivalentPhiWithSameType() == nullptr);
+    // If doing fix-point iteration, the equivalent might be in `worklist_`.
+    // Setting it dead will make UpdateType skip it.
+    equivalent->SetDead();
+    equivalent->ReplaceWith(phi);
+  }
+
+  return true;
+}
+
+void DeadPhiHandling::VisitBasicBlock(HBasicBlock* block) {
+  for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
+    HPhi* phi = it.Current()->AsPhi();
+    if (phi->IsDead() && phi->HasEnvironmentUses()) {
+      phi->SetLive();
+      if (block->IsLoopHeader()) {
+        // Give a type to the loop phi to guarantee convergence of the algorithm.
+        // Note that the dead phi may already have a type if it is an equivalent
+        // generated for a typed LoadLocal. In that case we do not change the
+        // type because it could lead to an unsupported PrimNot/Float/Double ->
+        // PrimInt/Long transition and create same type equivalents.
+        if (phi->GetType() == Primitive::kPrimVoid) {
+          phi->SetType(phi->InputAt(0)->GetType());
+        }
+        AddToWorklist(phi);
+      } else {
+        // Because we are doing a reverse post order visit, all inputs of
+        // this phi have been visited and therefore had their (initial) type set.
+        UpdateType(phi);
       }
     }
   }
 }
 
+void DeadPhiHandling::ProcessWorklist() {
+  while (!worklist_.empty()) {
+    HPhi* instruction = worklist_.back();
+    worklist_.pop_back();
+    // Note that the same equivalent phi can be added multiple times in the work list, if
+    // used by multiple phis. The first call to `UpdateType` will know whether the phi is
+    // dead or live.
+    if (instruction->IsLive() && UpdateType(instruction)) {
+      AddDependentInstructionsToWorklist(instruction);
+    }
+  }
+}
+
+void DeadPhiHandling::AddToWorklist(HPhi* instruction) {
+  DCHECK(instruction->IsLive());
+  worklist_.push_back(instruction);
+}
+
+void DeadPhiHandling::AddDependentInstructionsToWorklist(HPhi* instruction) {
+  for (HUseIterator<HInstruction*> it(instruction->GetUses()); !it.Done(); it.Advance()) {
+    HPhi* phi = it.Current()->GetUser()->AsPhi();
+    if (phi != nullptr && !phi->IsDead()) {
+      AddToWorklist(phi);
+    }
+  }
+}
+
+void DeadPhiHandling::Run() {
+  for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) {
+    VisitBasicBlock(it.Current());
+  }
+  ProcessWorklist();
+}
+
 void SsaBuilder::FixNullConstantType() {
   // The order doesn't matter here.
   for (HReversePostOrderIterator itb(*GetGraph()); !itb.Done(); itb.Advance()) {
@@ -73,11 +259,10 @@
       HPhi* phi = it.Current()->AsPhi();
       HPhi* next = phi->GetNextEquivalentPhiWithSameType();
       if (next != nullptr) {
-        // Make sure we do not replace a live phi with a dead phi. A live phi
-        // has been handled by the type propagation phase, unlike a dead phi.
+        // Make sure we do not replace a live phi with a dead phi. A live phi has been
+        // handled by the type propagation phase, unlike a dead phi.
         if (next->IsLive()) {
           phi->ReplaceWith(next);
-          phi->SetDead();
         } else {
           next->ReplaceWith(phi);
         }
@@ -89,7 +274,72 @@
   }
 }
 
-void SsaBuilder::FixEnvironmentPhis() {
+void SsaBuilder::BuildSsa() {
+  // 1) Visit in reverse post order. We need to have all predecessors of a block visited
+  // (with the exception of loops) in order to create the right environment for that
+  // block. For loops, we create phis whose inputs will be set in 2).
+  for (HReversePostOrderIterator it(*GetGraph()); !it.Done(); it.Advance()) {
+    VisitBasicBlock(it.Current());
+  }
+
+  // 2) Set inputs of loop phis.
+  for (HBasicBlock* block : loop_headers_) {
+    for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
+      HPhi* phi = it.Current()->AsPhi();
+      for (HBasicBlock* predecessor : block->GetPredecessors()) {
+        HInstruction* input = ValueOfLocal(predecessor, phi->GetRegNumber());
+        phi->AddInput(input);
+      }
+    }
+  }
+
+  // 3) Mark dead phis. This will mark phis that are only used by environments:
+  // at the DEX level, the type of these phis does not need to be consistent, but
+  // our code generator will complain if the inputs of a phi do not have the same
+  // type. The marking allows the type propagation to know which phis it needs
+  // to handle. We mark but do not eliminate: the elimination will be done in
+  // step 9).
+  SsaDeadPhiElimination dead_phis_for_type_propagation(GetGraph());
+  dead_phis_for_type_propagation.MarkDeadPhis();
+
+  // 4) Propagate types of phis. At this point, phis are typed void in the general
+  // case, or float/double/reference when we created an equivalent phi. So we
+  // need to propagate the types across phis to give them a correct type.
+  PrimitiveTypePropagation type_propagation(GetGraph());
+  type_propagation.Run();
+
+  // 5) When creating equivalent phis we copy the inputs of the original phi which
+  // may be improperly typed. This was fixed during the type propagation in 4) but
+  // as a result we may end up with two equivalent phis with the same type for
+  // the same dex register. This pass cleans them up.
+  EquivalentPhisCleanup();
+
+  // 6) Mark dead phis again. Step 4) may have introduced new phis.
+  // Step 5) might enable the death of new phis.
+  SsaDeadPhiElimination dead_phis(GetGraph());
+  dead_phis.MarkDeadPhis();
+
+  // 7) Now that the graph is correctly typed, we can get rid of redundant phis.
+  // Note that we cannot do this phase before type propagation, otherwise
+  // we could get rid of phi equivalents, whose presence is a requirement for the
+  // type propagation phase. Note that this is to satisfy statement (a) of the
+  // SsaBuilder (see ssa_builder.h).
+  SsaRedundantPhiElimination redundant_phi(GetGraph());
+  redundant_phi.Run();
+
+  // 8) Fix the type for null constants which are part of an equality comparison.
+  // We need to do this after redundant phi elimination, to ensure the only cases
+  // that we can see are reference comparison against 0. The redundant phi
+  // elimination ensures we do not see a phi taking two 0 constants in a HEqual
+  // or HNotEqual.
+  FixNullConstantType();
+
+  // 9) Make sure environments use the right phi "equivalent": a phi marked dead
+  // can have a phi equivalent that is not dead. We must therefore update
+  // all environment uses of the dead phi to use its equivalent. Note that there
+  // can be multiple phis for the same Dex register that are live (for example
+  // when merging constants), in which case it is OK for the environments
+  // to just reference one.
   for (HReversePostOrderIterator it(*GetGraph()); !it.Done(); it.Advance()) {
     HBasicBlock* block = it.Current();
     for (HInstructionIterator it_phis(block->GetPhis()); !it_phis.Done(); it_phis.Advance()) {
@@ -110,68 +360,24 @@
       phi->ReplaceWith(next);
     }
   }
-}
 
-void SsaBuilder::BuildSsa() {
-  // 1) Visit in reverse post order. We need to have all predecessors of a block visited
-  // (with the exception of loops) in order to create the right environment for that
-  // block. For loops, we create phis whose inputs will be set in 2).
-  for (HReversePostOrderIterator it(*GetGraph()); !it.Done(); it.Advance()) {
-    VisitBasicBlock(it.Current());
+  // 10) Deal with phis to guarantee liveness of phis in case of a debuggable
+  // application. This is for satisfying statement (c) of the SsaBuilder
+  // (see ssa_builder.h).
+  if (GetGraph()->IsDebuggable()) {
+    DeadPhiHandling dead_phi_handler(GetGraph());
+    dead_phi_handler.Run();
   }
 
-  // 2) Set inputs of loop phis.
-  SetLoopPhiInputs();
-
-  // 3) Propagate types of phis. At this point, phis are typed void in the general
-  // case, or float/double/reference if we created an equivalent phi. So we need
-  // to propagate the types across phis to give them a correct type. If a type
-  // conflict is detected in this stage, the phi is marked dead.
-  PrimitiveTypePropagation(GetGraph()).Run();
-
-  // 4) When creating equivalent phis we copy the inputs of the original phi which
-  // may be improperly typed. This was fixed during the type propagation in 4) but
-  // as a result we may end up with two equivalent phis with the same type for
-  // the same dex register. This pass cleans them up.
-  EquivalentPhisCleanup();
-
-  // 5) Mark dead phis. This will mark phis which are not used by instructions or
-  // other live phis. If compiling as debuggable code, phis will also be kept live
-  // if they have an environment use.
-  SsaDeadPhiElimination dead_phis(GetGraph());
-  dead_phis.MarkDeadPhis();
-
-  // 6) Make sure environments use the right phi equivalent: a phi marked dead
-  // can have a phi equivalent that is not dead. In that case we have to replace
-  // it with the live equivalent because deoptimization and try/catch rely on
-  // environments containing values of all live vregs at that point. Note that
-  // there can be multiple phis for the same Dex register that are live
-  // (for example when merging constants), in which case it is okay for the
-  // environments to just reference one.
-  FixEnvironmentPhis();
-
-  // 7) Now that the right phis are used for the environments, we can eliminate
-  // phis we do not need. Regardless of the debuggable status, this phase is
-  /// necessary for statement (b) of the SsaBuilder (see ssa_builder.h), as well
-  // as for the code generation, which does not deal with phis of conflicting
+  // 11) Now that the right phis are used for the environments, and we
+  // have potentially revive dead phis in case of a debuggable application,
+  // we can eliminate phis we do not need. Regardless of the debuggable status,
+  // this phase is necessary for statement (b) of the SsaBuilder (see ssa_builder.h),
+  // as well as for the code generation, which does not deal with phis of conflicting
   // input types.
   dead_phis.EliminateDeadPhis();
 
-  // 8) Now that the graph is correctly typed, we can get rid of redundant phis.
-  // Note that we cannot do this phase before type propagation, otherwise
-  // we could get rid of phi equivalents, whose presence is a requirement for the
-  // type propagation phase. Note that this is to satisfy statement (a) of the
-  // SsaBuilder (see ssa_builder.h).
-  SsaRedundantPhiElimination(GetGraph()).Run();
-
-  // 9) Fix the type for null constants which are part of an equality comparison.
-  // We need to do this after redundant phi elimination, to ensure the only cases
-  // that we can see are reference comparison against 0. The redundant phi
-  // elimination ensures we do not see a phi taking two 0 constants in a HEqual
-  // or HNotEqual.
-  FixNullConstantType();
-
-  // 10) Clear locals.
+  // 12) Clear locals.
   for (HInstructionIterator it(GetGraph()->GetEntryBlock()->GetInstructions());
        !it.Done();
        it.Advance()) {
@@ -355,8 +561,6 @@
  * phi with a floating point / reference type.
  */
 HPhi* SsaBuilder::GetFloatDoubleOrReferenceEquivalentOfPhi(HPhi* phi, Primitive::Type type) {
-  DCHECK(phi->IsLive()) << "Cannot get equivalent of a dead phi since it would create a live one.";
-
   // We place the floating point /reference phi next to this phi.
   HInstruction* next = phi->GetNext();
   if (next != nullptr
@@ -372,18 +576,15 @@
     ArenaAllocator* allocator = phi->GetBlock()->GetGraph()->GetArena();
     HPhi* new_phi = new (allocator) HPhi(allocator, phi->GetRegNumber(), phi->InputCount(), type);
     for (size_t i = 0, e = phi->InputCount(); i < e; ++i) {
-      // Copy the inputs. Note that the graph may not be correctly typed
-      // by doing this copy, but the type propagation phase will fix it.
+      // Copy the inputs. Note that the graph may not be correctly typed by doing this copy,
+      // but the type propagation phase will fix it.
       new_phi->SetRawInputAt(i, phi->InputAt(i));
     }
     phi->GetBlock()->InsertPhiAfter(new_phi, phi);
-    DCHECK(new_phi->IsLive());
     return new_phi;
   } else {
     DCHECK_EQ(next->GetType(), type);
-    // An existing equivalent was found. If it is dead, conflict was previously
-    // identified and we return nullptr instead.
-    return next->AsPhi()->IsLive() ? next->AsPhi() : nullptr;
+    return next->AsPhi();
   }
 }
 
@@ -391,15 +592,11 @@
                                                      HInstruction* value,
                                                      Primitive::Type type) {
   if (value->IsArrayGet()) {
-    HArrayGet* aget = value->AsArrayGet();
-    if (aget->GetType() != type && aget->IsTypeFixed()) {
-      // Requested a float/double equivalent of ArrayGet with int/long uses.
-      // Must be a phi with type conflict.
-      DCHECK(user->IsPhi());
-      return nullptr;
-    }
-    aget->SetType(type);
-    return aget;
+    // The verifier has checked that values in arrays cannot be used for both
+    // floating point and non-floating point operations. It is therefore safe to just
+    // change the type of the operation.
+    value->AsArrayGet()->SetType(type);
+    return value;
   } else if (value->IsLongConstant()) {
     return GetDoubleEquivalent(value->AsLongConstant());
   } else if (value->IsIntConstant()) {
@@ -407,7 +604,12 @@
   } else if (value->IsPhi()) {
     return GetFloatDoubleOrReferenceEquivalentOfPhi(value->AsPhi(), type);
   } else {
-    return nullptr;
+    // For other instructions, we assume the verifier has checked that the dex format is correctly
+    // typed and the value in a dex register will not be used for both floating point and
+    // non-floating point operations. So the only reason an instruction would want a floating
+    // point equivalent is for an unused phi that will be removed by the dead phi elimination phase.
+    DCHECK(user->IsPhi()) << "is actually " << user->DebugName() << " (" << user->GetId() << ")";
+    return value;
   }
 }
 
@@ -431,21 +633,6 @@
       value = GetReferenceTypeEquivalent(value);
     }
   }
-
-  // If value is HArrayGet, check if uses of the HLoadLocal disambiguate its
-  // type between int/long and float/double.
-  if (value->IsArrayGet() && !value->AsArrayGet()->IsTypeFixed()) {
-    for (HUseIterator<HInstruction*> use_it(load->GetUses()); !use_it.Done(); use_it.Advance()) {
-      HInstruction* user = use_it.Current()->GetUser();
-      if (!user->IsStoreLocal() &&
-          !user->IsPhi() &&
-          (!user->IsArraySet() || user->AsArraySet()->GetIndex() == value)) {
-        value->AsArrayGet()->FixType();
-        break;
-      }
-    }
-  }
-
   load->ReplaceWith(value);
   load->GetBlock()->RemoveInstruction(load);
 }
diff --git a/compiler/optimizing/ssa_builder.h b/compiler/optimizing/ssa_builder.h
index da0583c..79f1a28 100644
--- a/compiler/optimizing/ssa_builder.h
+++ b/compiler/optimizing/ssa_builder.h
@@ -81,8 +81,6 @@
   static constexpr const char* kSsaBuilderPassName = "ssa_builder";
 
  private:
-  void SetLoopPhiInputs();
-  void FixEnvironmentPhis();
   void FixNullConstantType();
   void EquivalentPhisCleanup();
 
diff --git a/compiler/optimizing/ssa_phi_elimination.cc b/compiler/optimizing/ssa_phi_elimination.cc
index c6993f3..72f9ddd 100644
--- a/compiler/optimizing/ssa_phi_elimination.cc
+++ b/compiler/optimizing/ssa_phi_elimination.cc
@@ -29,28 +29,17 @@
     HBasicBlock* block = it.Current();
     for (HInstructionIterator inst_it(block->GetPhis()); !inst_it.Done(); inst_it.Advance()) {
       HPhi* phi = inst_it.Current()->AsPhi();
-      if (phi->IsDead()) {
-        // Phis are constructed live so this one was proven conflicting.
-        continue;
-      }
-
-      bool is_live = false;
-      if (graph_->IsDebuggable() && phi->HasEnvironmentUses()) {
-        is_live = true;
-      } else {
-        for (HUseIterator<HInstruction*> use_it(phi->GetUses()); !use_it.Done(); use_it.Advance()) {
-          if (!use_it.Current()->GetUser()->IsPhi()) {
-            is_live = true;
-            break;
-          }
+      // Set dead ahead of running through uses. The phi may have no use.
+      phi->SetDead();
+      for (HUseIterator<HInstruction*> use_it(phi->GetUses()); !use_it.Done(); use_it.Advance()) {
+        HUseListNode<HInstruction*>* current = use_it.Current();
+        HInstruction* user = current->GetUser();
+        if (!user->IsPhi()) {
+          worklist_.push_back(phi);
+          phi->SetLive();
+          break;
         }
       }
-
-      if (is_live) {
-        worklist_.push_back(phi);
-      } else {
-        phi->SetDead();
-      }
     }
   }
 
@@ -61,10 +50,8 @@
     for (HInputIterator it(phi); !it.Done(); it.Advance()) {
       HInstruction* input = it.Current();
       if (input->IsPhi() && input->AsPhi()->IsDead()) {
-        // If we revive a phi it must have been live at the beginning of
-        // the pass but had no non-phi uses of its own.
-        input->AsPhi()->SetLive();
         worklist_.push_back(input->AsPhi());
+        input->AsPhi()->SetLive();
       }
     }
   }
@@ -88,8 +75,8 @@
           for (HUseIterator<HInstruction*> use_it(phi->GetUses()); !use_it.Done();
                use_it.Advance()) {
             HInstruction* user = use_it.Current()->GetUser();
-            DCHECK(user->IsPhi());
-            DCHECK(user->AsPhi()->IsDead());
+            DCHECK(user->IsLoopHeaderPhi()) << user->GetId();
+            DCHECK(user->AsPhi()->IsDead()) << user->GetId();
           }
         }
         // Remove the phi from use lists of its inputs.
diff --git a/test/538-checker-typeprop-debuggable/expected.txt b/test/538-checker-typeprop-debuggable/expected.txt
deleted file mode 100644
index e69de29..0000000
--- a/test/538-checker-typeprop-debuggable/expected.txt
+++ /dev/null
diff --git a/test/538-checker-typeprop-debuggable/info.txt b/test/538-checker-typeprop-debuggable/info.txt
deleted file mode 100644
index 9d69056..0000000
--- a/test/538-checker-typeprop-debuggable/info.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-Test that phis with environment uses which can be properly typed are kept
-in --debuggable mode.
\ No newline at end of file
diff --git a/test/538-checker-typeprop-debuggable/smali/ArrayGet.smali b/test/538-checker-typeprop-debuggable/smali/ArrayGet.smali
deleted file mode 100644
index 19583af..0000000
--- a/test/538-checker-typeprop-debuggable/smali/ArrayGet.smali
+++ /dev/null
@@ -1,167 +0,0 @@
-# Copyright (C) 2015 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-.class public LArrayGet;
-.super Ljava/lang/Object;
-
-
-# Test phi with fixed-type ArrayGet as an input and a matching second input.
-# The phi should be typed accordingly.
-
-## CHECK-START: void ArrayGet.matchingFixedType(float[], float) ssa_builder (after)
-## CHECK-NOT: Phi
-
-## CHECK-START-DEBUGGABLE: void ArrayGet.matchingFixedType(float[], float) ssa_builder (after)
-## CHECK-DAG:  <<Arg1:f\d+>> ParameterValue
-## CHECK-DAG:  <<Aget:f\d+>> ArrayGet
-## CHECK-DAG:  {{f\d+}}      Phi [<<Aget>>,<<Arg1>>] reg:0
-.method public static matchingFixedType([FF)V
-  .registers 8
-
-  const v0, 0x0
-  const v1, 0x1
-
-  aget v0, p0, v0       # read value
-  add-float v2, v0, v1  # float use fixes type
-
-  float-to-int v2, p1
-  if-eqz v2, :after
-  move v0, p1
-  :after
-  # v0 = Phi [ArrayGet, Arg1] => float
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-
-# Test phi with fixed-type ArrayGet as an input and a conflicting second input.
-# The phi should be eliminated due to the conflict.
-
-## CHECK-START: void ArrayGet.conflictingFixedType(float[], int) ssa_builder (after)
-## CHECK-NOT: Phi
-
-## CHECK-START-DEBUGGABLE: void ArrayGet.conflictingFixedType(float[], int) ssa_builder (after)
-## CHECK-NOT: Phi
-.method public static conflictingFixedType([FI)V
-  .registers 8
-
-  const v0, 0x0
-  const v1, 0x1
-
-  aget v0, p0, v0       # read value
-  add-float v2, v0, v1  # float use fixes type
-
-  if-eqz p1, :after
-  move v0, p1
-  :after
-  # v0 = Phi [ArrayGet, Arg1] => conflict
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-
-# Same test as the one above, only this time tests that type of ArrayGet is not
-# changed.
-
-## CHECK-START: void ArrayGet.conflictingFixedType2(int[], float) ssa_builder (after)
-## CHECK-NOT: Phi
-
-## CHECK-START-DEBUGGABLE: void ArrayGet.conflictingFixedType2(int[], float) ssa_builder (after)
-## CHECK-NOT: Phi
-
-## CHECK-START-DEBUGGABLE: void ArrayGet.conflictingFixedType2(int[], float) ssa_builder (after)
-## CHECK:     {{i\d+}} ArrayGet
-.method public static conflictingFixedType2([IF)V
-  .registers 8
-
-  const v0, 0x0
-  const v1, 0x1
-
-  aget v0, p0, v0       # read value
-  add-int v2, v0, v1    # int use fixes type
-
-  float-to-int v2, p1
-  if-eqz v2, :after
-  move v0, p1
-  :after
-  # v0 = Phi [ArrayGet, Arg1] => conflict
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-
-# Test phi with free-type ArrayGet as an input and a matching second input.
-# The phi should be typed accordingly.
-
-## CHECK-START: void ArrayGet.matchingFreeType(float[], float) ssa_builder (after)
-## CHECK-NOT: Phi
-
-## CHECK-START-DEBUGGABLE: void ArrayGet.matchingFreeType(float[], float) ssa_builder (after)
-## CHECK-DAG:  <<Arg1:f\d+>> ParameterValue
-## CHECK-DAG:  <<Aget:f\d+>> ArrayGet
-## CHECK-DAG:                ArraySet [{{l\d+}},{{i\d+}},<<Aget>>]
-## CHECK-DAG:  {{f\d+}}      Phi [<<Aget>>,<<Arg1>>] reg:0
-.method public static matchingFreeType([FF)V
-  .registers 8
-
-  const v0, 0x0
-  const v1, 0x1
-
-  aget v0, p0, v0       # read value, should be float but has no typed use
-  aput v0, p0, v1       # aput does not disambiguate the type
-
-  float-to-int v2, p1
-  if-eqz v2, :after
-  move v0, p1
-  :after
-  # v0 = Phi [ArrayGet, Arg1] => float
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-
-# Test phi with free-type ArrayGet as an input and a conflicting second input.
-# The phi will be kept and typed according to the second input despite the
-# conflict.
-
-## CHECK-START: void ArrayGet.conflictingFreeType(int[], float) ssa_builder (after)
-## CHECK-NOT: Phi
-
-## CHECK-START-DEBUGGABLE: void ArrayGet.conflictingFreeType(int[], float) ssa_builder (after)
-## CHECK-DAG:  <<Arg1:f\d+>> ParameterValue
-## CHECK-DAG:  <<Aget:f\d+>> ArrayGet
-## CHECK-DAG:                ArraySet [{{l\d+}},{{i\d+}},<<Aget>>]
-## CHECK-DAG:  {{f\d+}}      Phi [<<Aget>>,<<Arg1>>] reg:0
-.method public static conflictingFreeType([IF)V
-  .registers 8
-
-  const v0, 0x0
-  const v1, 0x1
-
-  aget v0, p0, v0       # read value, should be int but has no typed use
-  aput v0, p0, v1       # aput does not disambiguate the type
-
-  float-to-int v2, p1
-  if-eqz v2, :after
-  move v0, p1
-  :after
-  # v0 = Phi [ArrayGet, Arg1] => float
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
diff --git a/test/538-checker-typeprop-debuggable/smali/SsaBuilder.smali b/test/538-checker-typeprop-debuggable/smali/SsaBuilder.smali
deleted file mode 100644
index 395feaa..0000000
--- a/test/538-checker-typeprop-debuggable/smali/SsaBuilder.smali
+++ /dev/null
@@ -1,52 +0,0 @@
-# Copyright (C) 2015 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-.class public LSsaBuilder;
-.super Ljava/lang/Object;
-
-# Check that a dead phi with a live equivalent is replaced in an environment. The
-# following test case throws an exception and uses v0 afterwards. However, v0
-# contains a phi that is interpreted as int for the environment, and as float for
-# instruction use. SsaBuilder must substitute the int variant before removing it,
-# otherwise running the code with an array short enough to throw will crash at
-# runtime because v0 is undefined.
-
-## CHECK-START: int SsaBuilder.environmentPhi(boolean, int[]) ssa_builder (after)
-## CHECK-DAG:     <<Cst0:f\d+>>  FloatConstant 0
-## CHECK-DAG:     <<Cst2:f\d+>>  FloatConstant 2
-## CHECK-DAG:     <<Phi:f\d+>>   Phi [<<Cst0>>,<<Cst2>>]
-## CHECK-DAG:                    BoundsCheck env:[[<<Phi>>,{{i\d+}},{{z\d+}},{{l\d+}}]]
-
-.method public static environmentPhi(Z[I)I
-  .registers 4
-
-  const v0, 0x0
-  if-eqz p0, :else
-  const v0, 0x40000000
-  :else
-  # v0 = phi that can be both int and float
-
-  :try_start
-  const v1, 0x3
-  aput v1, p1, v1
-  const v0, 0x1     # generate catch phi for v0
-  const v1, 0x4
-  aput v1, p1, v1
-  :try_end
-  .catchall {:try_start .. :try_end} :use_as_float
-
-  :use_as_float
-  float-to-int v0, v0
-  return v0
-.end method
\ No newline at end of file
diff --git a/test/538-checker-typeprop-debuggable/smali/TypePropagation.smali b/test/538-checker-typeprop-debuggable/smali/TypePropagation.smali
deleted file mode 100644
index 58682a1..0000000
--- a/test/538-checker-typeprop-debuggable/smali/TypePropagation.smali
+++ /dev/null
@@ -1,136 +0,0 @@
-# Copyright (C) 2015 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-.class public LTypePropagation;
-.super Ljava/lang/Object;
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeDeadPhi(boolean, boolean, int, float, float) ssa_builder (after)
-## CHECK-NOT: Phi
-.method public static mergeDeadPhi(ZZIFF)V
-  .registers 8
-
-  if-eqz p0, :after1
-  move p2, p3
-  :after1
-  # p2 = merge(int,float) = conflict
-
-  if-eqz p1, :after2
-  move p2, p4
-  :after2
-  # p2 = merge(conflict,float) = conflict
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeSameType(boolean, int, int) ssa_builder (after)
-## CHECK:     {{i\d+}} Phi
-## CHECK-NOT:          Phi
-.method public static mergeSameType(ZII)V
-  .registers 8
-  if-eqz p0, :after
-  move p1, p2
-  :after
-  # p1 = merge(int,int) = int
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeVoidInput(boolean, boolean, int, int) ssa_builder (after)
-## CHECK:     {{i\d+}} Phi
-## CHECK:     {{i\d+}} Phi
-## CHECK-NOT:          Phi
-.method public static mergeVoidInput(ZZII)V
-  .registers 8
-  :loop
-  # p2 = void (loop phi) => p2 = merge(int,int) = int
-  if-eqz p0, :after
-  move p2, p3
-  :after
-  # p2 = merge(void,int) = int
-  if-eqz p1, :loop
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeDifferentSize(boolean, int, long) ssa_builder (after)
-## CHECK-NOT: Phi
-.method public static mergeDifferentSize(ZIJ)V
-  .registers 8
-  if-eqz p0, :after
-  move-wide p1, p2
-  :after
-  # p1 = merge(int,long) = conflict
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeRefFloat(boolean, float, java.lang.Object) ssa_builder (after)
-## CHECK-NOT: Phi
-.method public static mergeRefFloat(ZFLjava/lang/Object;)V
-  .registers 8
-  if-eqz p0, :after
-  move-object p1, p2
-  :after
-  # p1 = merge(float,reference) = conflict
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeIntFloat_Success(boolean, float) ssa_builder (after)
-## CHECK:     {{f\d+}} Phi
-## CHECK-NOT:          Phi
-.method public static mergeIntFloat_Success(ZF)V
-  .registers 8
-  if-eqz p0, :after
-  const/4 p1, 0x0
-  :after
-  # p1 = merge(float,0x0) = float
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.mergeIntFloat_Fail(boolean, int, float) ssa_builder (after)
-## CHECK-NOT: Phi
-.method public static mergeIntFloat_Fail(ZIF)V
-  .registers 8
-  if-eqz p0, :after
-  move p1, p2
-  :after
-  # p1 = merge(int,float) = conflict
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
-
-## CHECK-START-DEBUGGABLE: void TypePropagation.updateAllUsersOnConflict(boolean, boolean, int, float, int) ssa_builder (after)
-## CHECK-NOT: Phi
-.method public static updateAllUsersOnConflict(ZZIFI)V
-  .registers 8
-
-  :loop1
-  # loop phis for all args
-  # p2 = merge(int,float) = float? => conflict
-  move p2, p3
-  if-eqz p0, :loop1
-
-  :loop2
-  # loop phis for all args
-  # requests float equivalent of p4 phi in loop1 => conflict
-  # propagates conflict to loop2's phis
-  move p2, p4
-  if-eqz p1, :loop2
-
-  invoke-static {}, Ljava/lang/System;->nanoTime()J  # create an env use
-  return-void
-.end method
diff --git a/test/538-checker-typeprop-debuggable/src/Main.java b/test/538-checker-typeprop-debuggable/src/Main.java
deleted file mode 100644
index fe2343e..0000000
--- a/test/538-checker-typeprop-debuggable/src/Main.java
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import java.lang.reflect.Method;
-
-public class Main {
-
-  // Workaround for b/18051191.
-  class InnerClass {}
-
-  private static void assertEquals(int expected, int actual) {
-    if (expected != actual) {
-      throw new Error("Wrong result, expected=" + expected + ", actual=" + actual);
-    }
-  }
-
-  public static void main(String[] args) throws Exception {
-    Class<?> c = Class.forName("SsaBuilder");
-    Method m = c.getMethod("environmentPhi", new Class[] { boolean.class, int[].class });
-
-    int[] array = new int[3];
-    int result;
-
-    result = (Integer) m.invoke(null, new Object[] { true, array } );
-    assertEquals(2, result);
-
-    result = (Integer) m.invoke(null, new Object[] { false, array } );
-    assertEquals(0, result);
-  }
-}