Merge CommonElements and BackendHelpers!

pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart

 // 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.
 
+import '../common_elements.dart' show CommonElements;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
 import '../elements/elements.dart' show Name;
 import '../elements/entities.dart';
-import '../js_backend/backend_helpers.dart';
 import '../options.dart';
 import '../types/types.dart';
 import '../universe/call_structure.dart';
 import '../universe/selector.dart';
 import '../world.dart' show ClosedWorld;
 import 'nodes.dart';
 import 'types.dart';
 
 /**
  * [InvokeDynamicSpecializer] and its subclasses are helpers to
  * optimize intercepted dynamic calls. It knows what input types
  * would be beneficial for performance, and how to change a invoke
  * dynamic to a builtin instruction (e.g. HIndex, HBitNot).
  */
 class InvokeDynamicSpecializer {
   const InvokeDynamicSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return TypeMaskFactory.inferredTypeForSelector(
         instruction.selector, instruction.mask, results);
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     return null;
   }
 
   void clearAllSideEffects(HInstruction instruction) {
     instruction.sideEffects.clearAllSideEffects();
     instruction.sideEffects.clearAllDependencies();
     instruction.setUseGvn();
   }
 
   Selector renameToOptimizedSelector(
-      String name, Selector selector, BackendHelpers helpers) {
+      String name, Selector selector, CommonElements commonElements) {
     if (selector.name == name) return selector;
-    return new Selector.call(new Name(name, helpers.interceptorsLibrary),
+    return new Selector.call(new Name(name, commonElements.interceptorsLibrary),
         new CallStructure(selector.argumentCount));
   }
 
   Operation operation(ConstantSystem constantSystem) => null;
 
   static InvokeDynamicSpecializer lookupSpecializer(Selector selector) {
     if (selector.isIndex) return const IndexSpecializer();
     if (selector.isIndexSet) return const IndexAssignSpecializer();
     String name = selector.name;
     if (selector.isOperator) {
@@ skipping 46 matching lines @@
 }
 
 class IndexAssignSpecializer extends InvokeDynamicSpecializer {
   const IndexAssignSpecializer();
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     if (instruction.inputs[1].isMutableIndexable(closedWorld)) {
       if (!instruction.inputs[2].isInteger(closedWorld) &&
           options.enableTypeAssertions) {
         // We want the right checked mode error.
         return null;
       }
       return new HIndexAssign(instruction.inputs[1], instruction.inputs[2],
           instruction.inputs[3], instruction.selector);
     }
     return null;
   }
 }
 
 class IndexSpecializer extends InvokeDynamicSpecializer {
   const IndexSpecializer();
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     if (!instruction.inputs[1].isIndexablePrimitive(closedWorld)) return null;
     if (!instruction.inputs[2].isInteger(closedWorld) &&
         options.enableTypeAssertions) {
       // We want the right checked mode error.
       return null;
     }
     TypeMask receiverType =
         instruction.getDartReceiver(closedWorld).instructionType;
     TypeMask type = TypeMaskFactory.inferredTypeForSelector(
         instruction.selector, receiverType, results);
     return new HIndex(instruction.inputs[1], instruction.inputs[2],
         instruction.selector, type);
   }
 }
 
 class BitNotSpecializer extends InvokeDynamicSpecializer {
   const BitNotSpecializer();
 
   UnaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.bitNot;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     // All bitwise operations on primitive types either produce an
     // integer or throw an error.
     if (instruction.inputs[1].isPrimitiveOrNull(closedWorld)) {
       return closedWorld.commonMasks.uint32Type;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction input = instruction.inputs[1];
     if (input.isNumber(closedWorld)) {
       return new HBitNot(
           input,
           instruction.selector,
           computeTypeFromInputTypes(
-              instruction, results, options, helpers, closedWorld));
+              instruction, results, options, closedWorld));
     }
     return null;
   }
 }
 
 class UnaryNegateSpecializer extends InvokeDynamicSpecializer {
   const UnaryNegateSpecializer();
 
   UnaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.negate;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     TypeMask operandType = instruction.inputs[1].instructionType;
     if (instruction.inputs[1].isNumberOrNull(closedWorld)) return operandType;
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction input = instruction.inputs[1];
     if (input.isNumber(closedWorld)) {
       return new HNegate(input, instruction.selector, input.instructionType);
     }
     return null;
   }
 }
 
 abstract class BinaryArithmeticSpecializer extends InvokeDynamicSpecializer {
   const BinaryArithmeticSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isIntegerOrNull(closedWorld) &&
         right.isIntegerOrNull(closedWorld)) {
       return closedWorld.commonMasks.intType;
     }
     if (left.isNumberOrNull(closedWorld)) {
       if (left.isDoubleOrNull(closedWorld) ||
           right.isDoubleOrNull(closedWorld)) {
         return closedWorld.commonMasks.doubleType;
       }
       return closedWorld.commonMasks.numType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   bool isBuiltin(HInvokeDynamic instruction, ClosedWorld closedWorld) {
     return instruction.inputs[1].isNumber(closedWorld) &&
         instruction.inputs[2].isNumber(closedWorld);
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     if (isBuiltin(instruction, closedWorld)) {
-      HInstruction builtin = newBuiltinVariant(
-          instruction, results, options, helpers, closedWorld);
+      HInstruction builtin =
+          newBuiltinVariant(instruction, results, options, closedWorld);
       if (builtin != null) return builtin;
       // Even if there is no builtin equivalent instruction, we know
       // the instruction does not have any side effect, and that it
       // can be GVN'ed.
       clearAllSideEffects(instruction);
     }
     return null;
   }
 
   bool inputsArePositiveIntegers(
       HInstruction instruction, ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     return left.isPositiveIntegerOrNull(closedWorld) &&
         right.isPositiveIntegerOrNull(closedWorld);
   }
 
   bool inputsAreUInt31(HInstruction instruction, ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     return left.isUInt31(closedWorld) && right.isUInt31(closedWorld);
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld);
 }
 
 class AddSpecializer extends BinaryArithmeticSpecializer {
   const AddSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     if (inputsAreUInt31(instruction, closedWorld)) {
       return closedWorld.commonMasks.uint32Type;
     }
     if (inputsArePositiveIntegers(instruction, closedWorld)) {
       return closedWorld.commonMasks.positiveIntType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.add;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HAdd(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class DivideSpecializer extends BinaryArithmeticSpecializer {
   const DivideSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.divide;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInstruction instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     if (left.isNumberOrNull(closedWorld)) {
       return closedWorld.commonMasks.doubleType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HDivide(instruction.inputs[1], instruction.inputs[2],
         instruction.selector, closedWorld.commonMasks.doubleType);
   }
 }
 
 class ModuloSpecializer extends BinaryArithmeticSpecializer {
   const ModuloSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     if (inputsArePositiveIntegers(instruction, closedWorld)) {
       return closedWorld.commonMasks.positiveIntType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.modulo;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     // Modulo cannot be mapped to the native operator (different semantics).
 
     // We can use HRemainder if both inputs are non-negative and the receiver
     // cannot be -0.0.  Note that -0.0 is considered to be an int, so until we
     // track -0.0 precisely, we have to syntatically filter inputs that cannot
     // generate -0.0.
     bool canBePositiveZero(HInstruction input) {
       if (input is HConstant) {
         ConstantValue value = input.constant;
@@ skipping 28 matching lines @@
       return true;
     }
 
     if (inputsArePositiveIntegers(instruction, closedWorld) &&
         !canBeNegativeZero(instruction.getDartReceiver(closedWorld))) {
       return new HRemainder(
           instruction.inputs[1],
           instruction.inputs[2],
           instruction.selector,
           computeTypeFromInputTypes(
-              instruction, results, options, helpers, closedWorld));
+              instruction, results, options, closedWorld));
     }
     // TODO(sra):
     //   a % N -->  a & (N-1), N=2^k, where a>=0, does not have -0.0 problem.
 
     // TODO(sra): We could avoid problems with -0.0 if we generate x % y as (x +
     // 0) % y, but we would have to fix HAdd optimizations.
 
     // TODO(sra): We could replace $mod with HRemainder when we don't care about
     // a -0.0 result (e.g. a % 10 == 0, a[i % 3]). This is tricky, since we
     // don't want to ruin GVN opportunities.
     return null;
   }
 }
 
 class RemainderSpecializer extends BinaryArithmeticSpecializer {
   const RemainderSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     if (inputsArePositiveIntegers(instruction, closedWorld)) {
       return closedWorld.commonMasks.positiveIntType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.remainder;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HRemainder(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class MultiplySpecializer extends BinaryArithmeticSpecializer {
   const MultiplySpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.multiply;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     if (inputsArePositiveIntegers(instruction, closedWorld)) {
       return closedWorld.commonMasks.positiveIntType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HMultiply(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class SubtractSpecializer extends BinaryArithmeticSpecializer {
   const SubtractSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.subtract;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HSubtract(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class TruncatingDivideSpecializer extends BinaryArithmeticSpecializer {
   const TruncatingDivideSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.truncatingDivide;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     if (hasUint31Result(instruction, closedWorld)) {
       return closedWorld.commonMasks.uint31Type;
     }
     if (inputsArePositiveIntegers(instruction, closedWorld)) {
       return closedWorld.commonMasks.positiveIntType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   bool isNotZero(HInstruction instruction) {
     if (!instruction.isConstantInteger()) return false;
     HConstant rightConstant = instruction;
     IntConstantValue intConstant = rightConstant.constant;
     int count = intConstant.primitiveValue;
     return count != 0;
   }
 
@@ skipping 17 matching lines @@
       }
     }
     return false;
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction right = instruction.inputs[2];
     if (isBuiltin(instruction, closedWorld)) {
       if (right.isPositiveInteger(closedWorld) && isNotZero(right)) {
         if (hasUint31Result(instruction, closedWorld)) {
-          return newBuiltinVariant(
-              instruction, results, options, helpers, closedWorld);
+          return newBuiltinVariant(instruction, results, options, closedWorld);
         }
         // We can call _tdivFast because the rhs is a 32bit integer
         // and not 0, nor -1.
         instruction.selector = renameToOptimizedSelector(
-            '_tdivFast', instruction.selector, helpers);
+            '_tdivFast', instruction.selector, commonElements);
       }
       clearAllSideEffects(instruction);
     }
     return null;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HTruncatingDivide(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 abstract class BinaryBitOpSpecializer extends BinaryArithmeticSpecializer {
   const BinaryBitOpSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     // All bitwise operations on primitive types either produce an
     // integer or throw an error.
     HInstruction left = instruction.inputs[1];
     if (left.isPrimitiveOrNull(closedWorld)) {
       return closedWorld.commonMasks.uint32Type;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   bool argumentLessThan32(HInstruction instruction) {
     return argumentInRange(instruction, 0, 31);
   }
 
   bool argumentInRange(HInstruction instruction, int low, int high) {
     if (instruction.isConstantInteger()) {
       HConstant rightConstant = instruction;
       IntConstantValue intConstant = rightConstant.constant;
@@ skipping 21 matching lines @@
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.shiftLeft;
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isNumber(closedWorld)) {
       if (argumentLessThan32(right)) {
-        return newBuiltinVariant(
-            instruction, results, options, helpers, closedWorld);
+        return newBuiltinVariant(instruction, results, options, closedWorld);
       }
       // Even if there is no builtin equivalent instruction, we know
       // the instruction does not have any side effect, and that it
       // can be GVN'ed.
       clearAllSideEffects(instruction);
       if (isPositive(right, closedWorld)) {
         instruction.selector = renameToOptimizedSelector(
-            '_shlPositive', instruction.selector, helpers);
+            '_shlPositive', instruction.selector, commonElements);
       }
     }
     return null;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HShiftLeft(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class ShiftRightSpecializer extends BinaryBitOpSpecializer {
   const ShiftRightSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     if (left.isUInt32(closedWorld)) return left.instructionType;
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isNumber(closedWorld)) {
       if (argumentLessThan32(right) && isPositive(left, closedWorld)) {
-        return newBuiltinVariant(
-            instruction, results, options, helpers, closedWorld);
+        return newBuiltinVariant(instruction, results, options, closedWorld);
       }
       // Even if there is no builtin equivalent instruction, we know
       // the instruction does not have any side effect, and that it
       // can be GVN'ed.
       clearAllSideEffects(instruction);
       if (isPositive(right, closedWorld) && isPositive(left, closedWorld)) {
         instruction.selector = renameToOptimizedSelector(
-            '_shrBothPositive', instruction.selector, helpers);
+            '_shrBothPositive', instruction.selector, commonElements);
       } else if (isPositive(left, closedWorld) && right.isNumber(closedWorld)) {
         instruction.selector = renameToOptimizedSelector(
-            '_shrReceiverPositive', instruction.selector, helpers);
+            '_shrReceiverPositive', instruction.selector, commonElements);
       } else if (isPositive(right, closedWorld)) {
         instruction.selector = renameToOptimizedSelector(
-            '_shrOtherPositive', instruction.selector, helpers);
+            '_shrOtherPositive', instruction.selector, commonElements);
       }
     }
     return null;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HShiftRight(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.shiftRight;
   }
 }
 
 class BitOrSpecializer extends BinaryBitOpSpecializer {
   const BitOrSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.bitOr;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isUInt31(closedWorld) && right.isUInt31(closedWorld)) {
       return closedWorld.commonMasks.uint31Type;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HBitOr(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class BitAndSpecializer extends BinaryBitOpSpecializer {
   const BitAndSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.bitAnd;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isPrimitiveOrNull(closedWorld) &&
         (left.isUInt31(closedWorld) || right.isUInt31(closedWorld))) {
       return closedWorld.commonMasks.uint31Type;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HBitAnd(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 class BitXorSpecializer extends BinaryBitOpSpecializer {
   const BitXorSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.bitXor;
   }
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isUInt31(closedWorld) && right.isUInt31(closedWorld)) {
       return closedWorld.commonMasks.uint31Type;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     return new HBitXor(
         instruction.inputs[1],
         instruction.inputs[2],
         instruction.selector,
-        computeTypeFromInputTypes(
-            instruction, results, options, helpers, closedWorld));
+        computeTypeFromInputTypes(instruction, results, options, closedWorld));
   }
 }
 
 abstract class RelationalSpecializer extends InvokeDynamicSpecializer {
   const RelationalSpecializer();
 
   TypeMask computeTypeFromInputTypes(
       HInvokeDynamic instruction,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
       ClosedWorld closedWorld) {
     if (instruction.inputs[1].isPrimitiveOrNull(closedWorld)) {
       return closedWorld.commonMasks.boolType;
     }
-    return super.computeTypeFromInputTypes(
-        instruction, results, options, helpers, closedWorld);
+    return super
+        .computeTypeFromInputTypes(instruction, results, options, closedWorld);
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     if (left.isNumber(closedWorld) && right.isNumber(closedWorld)) {
       return newBuiltinVariant(instruction, closedWorld);
     }
     return null;
   }
 
   HInstruction newBuiltinVariant(
       HInvokeDynamic instruction, ClosedWorld closedWorld);
 }
 
 class EqualsSpecializer extends RelationalSpecializer {
   const EqualsSpecializer();
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     TypeMask instructionType = left.instructionType;
     if (right.isConstantNull() || left.isPrimitiveOrNull(closedWorld)) {
       return newBuiltinVariant(instruction, closedWorld);
     }
     Iterable<MemberEntity> matches =
         closedWorld.allFunctions.filter(instruction.selector, instructionType);
     // This test relies the on `Object.==` and `Interceptor.==` always being
@@ skipping 78 matching lines @@
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.codeUnitAt;
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     // TODO(sra): Implement a builtin HCodeUnitAt instruction and the same index
     // bounds checking optimizations as for HIndex.
     HInstruction receiver = instruction.getDartReceiver(closedWorld);
     if (receiver.isStringOrNull(closedWorld)) {
       // Even if there is no builtin equivalent instruction, we know
       // String.codeUnitAt does not have any side effect (other than throwing),
       // and that it can be GVN'ed.
       clearAllSideEffects(instruction);
       if (instruction.inputs.last.isPositiveInteger(closedWorld)) {
         instruction.selector = renameToOptimizedSelector(
-            '_codeUnitAt', instruction.selector, helpers);
+            '_codeUnitAt', instruction.selector, commonElements);
       }
     }
     return null;
   }
 }
 
 class CompareToSpecializer extends InvokeDynamicSpecializer {
   const CompareToSpecializer();
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction receiver = instruction.getDartReceiver(closedWorld);
     // `compareTo` has no side-effect (other than throwing) and can be GVN'ed
     // for some known types.
     if (receiver.isStringOrNull(closedWorld) ||
         receiver.isNumberOrNull(closedWorld)) {
       // Replace `a.compareTo(a)` with `0`, but only if receiver and argument
       // are such that no exceptions can be thrown.
       HInstruction argument = instruction.inputs.last;
       if ((receiver.isNumber(closedWorld) && argument.isNumber(closedWorld)) ||
           (receiver.isString(closedWorld) && argument.isString(closedWorld))) {
         if (identical(receiver.nonCheck(), argument.nonCheck())) {
           return graph.addConstantInt(0, closedWorld);
         }
       }
       clearAllSideEffects(instruction);
     }
     return null;
   }
 }
 
 class IdempotentStringOperationSpecializer extends InvokeDynamicSpecializer {
   const IdempotentStringOperationSpecializer();
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction receiver = instruction.getDartReceiver(closedWorld);
     if (receiver.isStringOrNull(closedWorld)) {
       // String.xxx does not have any side effect (other than throwing), and it
       // can be GVN'ed.
       clearAllSideEffects(instruction);
     }
     return null;
   }
 }
 
 class SubstringSpecializer extends IdempotentStringOperationSpecializer {
   const SubstringSpecializer();
 }
 
 class TrimSpecializer extends IdempotentStringOperationSpecializer {
   const TrimSpecializer();
 }
 
 class PatternMatchSpecializer extends InvokeDynamicSpecializer {
   const PatternMatchSpecializer();
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction receiver = instruction.getDartReceiver(closedWorld);
     HInstruction pattern = instruction.inputs[2];
     if (receiver.isStringOrNull(closedWorld) &&
         pattern.isStringOrNull(closedWorld)) {
       // String.contains(String s) does not have any side effect (other than
       // throwing), and it can be GVN'ed.
       clearAllSideEffects(instruction);
     }
     return null;
   }
 }
 
 class RoundSpecializer extends InvokeDynamicSpecializer {
   const RoundSpecializer();
 
   UnaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.round;
   }
 
   HInstruction tryConvertToBuiltin(
       HInvokeDynamic instruction,
       HGraph graph,
       GlobalTypeInferenceResults results,
       CompilerOptions options,
-      BackendHelpers helpers,
+      CommonElements commonElements,
       ClosedWorld closedWorld) {
     HInstruction receiver = instruction.getDartReceiver(closedWorld);
     if (receiver.isNumberOrNull(closedWorld)) {
       // Even if there is no builtin equivalent instruction, we know the
       // instruction does not have any side effect, and that it can be GVN'ed.
       clearAllSideEffects(instruction);
     }
     return null;
   }
 }