Reland "Add DoubleTestOp instruction"

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index 1fe4377941f990987729271f0acee23ef76ad06c..2876be7d7284602898e920d5549574ca2d4b03d5 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -497,6 +497,7 @@ class EmbeddedArray<T, 0> {
   M(UnboxedConstant)                                                           \
   M(CheckEitherNonSmi)                                                         \
   M(BinaryDoubleOp)                                                            \
+  M(DoubleTestOp)                                                              \
   M(MathUnary)                                                                 \
   M(MathMinMax)                                                                \
   M(Box)                                                                       \
@@ -5343,6 +5344,56 @@ class BinaryDoubleOpInstr : public TemplateDefinition<2, NoThrow, Pure> {
 };
 
 
+class DoubleTestOpInstr : public TemplateDefinition<1, NoThrow, Pure> {
+ public:
+  DoubleTestOpInstr(MethodRecognizer::Kind op_kind,
+                    Value* d,
+                    intptr_t deopt_id,
+                    TokenPosition token_pos)
+      : TemplateDefinition(deopt_id),
+        op_kind_(op_kind),
+        token_pos_(token_pos) {
+    SetInputAt(0, d);
+  }
+
+  Value* value() const { return inputs_[0]; }
+
+  MethodRecognizer::Kind op_kind() const { return op_kind_; }
+
+  virtual TokenPosition token_pos() const { return token_pos_; }
+
+  virtual bool CanDeoptimize() const { return false; }
+
+  virtual Representation RequiredInputRepresentation(intptr_t idx) const {
+    ASSERT(idx == 0);
+    return kUnboxedDouble;
+  }
+
+  virtual intptr_t DeoptimizationTarget() const {
+    // Direct access since this instruction cannot deoptimize, and the deopt-id
+    // was inherited from another instruction that could deoptimize.
+    return GetDeoptId();
+  }
+
+  PRINT_OPERANDS_TO_SUPPORT
+
+  DECLARE_INSTRUCTION(DoubleTestOp)
+  virtual CompileType ComputeType() const;
+
+  virtual Definition* Canonicalize(FlowGraph* flow_graph);
+
+  virtual bool AttributesEqual(Instruction* other) const {
+    return op_kind_ == other->AsDoubleTestOp()->op_kind();
+  }
+
+ private:
+  const MethodRecognizer::Kind op_kind_;
+  const TokenPosition token_pos_;
+
+  DISALLOW_COPY_AND_ASSIGN(DoubleTestOpInstr);
+};
+
+
 class BinaryFloat32x4OpInstr : public TemplateDefinition<2, NoThrow, Pure> {
  public:
   BinaryFloat32x4OpInstr(Token::Kind op_kind,