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

sdk/lib/_internal/compiler/implementation/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.
 
 part of ssa;
 
 /**
  * [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
@@ skipping 249 matching lines @@
   }
 
   bool isBuiltin(HInvokeDynamicMethod instruction, HTypeMap types) {
     return instruction.inputs[1].isNumber(types)
         && instruction.inputs[2].isNumber(types);
   }
 
   HInstruction tryConvertToBuiltin(HInvokeDynamicMethod instruction,
                                    HTypeMap types) {
     if (isBuiltin(instruction, types)) {
-      return newBuiltinVariant(instruction.inputs[1], instruction.inputs[2]);
+      HInstruction builtin =
+          newBuiltinVariant(instruction.inputs[1], instruction.inputs[2]);
+      if (builtin != null) return builtin;
+      // Even if there is no builtin equivalent instruction, we know
+      // the instruction is pure, and that it can be GVN'ed.
+      instruction.clearAllSideEffects();
+      instruction.clearAllDependencies();
+      instruction.setUseGvn();
     }
     return null;
   }
 
   HInstruction newBuiltinVariant(HInstruction left, HInstruction right);
 }
 
 class AddSpecializer extends BinaryArithmeticSpecializer {
   const AddSpecializer();
 
@@ skipping 37 matching lines @@
   }
 }
 
 class ModuloSpecializer extends BinaryArithmeticSpecializer {
   const ModuloSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.modulo;
   }
 
-  HInstruction tryConvertToBuiltin(HInvokeDynamicMethod instruction,
-                                   HTypeMap types) {
+  HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
     // Modulo cannot be mapped to the native operator (different semantics).    
     return null;
   }
-
-  HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
-    throw 'Modulo has no builtin variant';
-  }
 }
 
 class MultiplySpecializer extends BinaryArithmeticSpecializer {
   const MultiplySpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.multiply;
   }
 
   HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
@@ skipping 13 matching lines @@
   }
 }
 
 class TruncatingDivideSpecializer extends BinaryArithmeticSpecializer {
   const TruncatingDivideSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.truncatingDivide;
   }
 
-  HInstruction tryConvertToBuiltin(HInvokeDynamicMethod instruction,
-                                   HTypeMap types) {
+  HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
     // Truncating divide does not have a JS equivalent.    
     return null;
   }
-
-  HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
-    throw 'Truncating divide has no builtin variant';
-  }
 }
 
 abstract class BinaryBitOpSpecializer extends BinaryArithmeticSpecializer {
   const BinaryBitOpSpecializer();
 
   HType computeTypeFromInputTypes(HInvokeDynamicMethod instruction,
                                   HTypeMap types,
                                   Compiler compiler) {
     // All bitwise operations on primitive types either produce an
     // integer or throw an error.
@@ skipping 40 matching lines @@
   }
 
   HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
     return new HShiftLeft(left, right);
   }
 }
 
 class ShiftRightSpecializer extends BinaryBitOpSpecializer {
   const ShiftRightSpecializer();
 
-  HInstruction tryConvertToBuiltin(HInvokeDynamicMethod instruction,
-                                   HTypeMap types) {
+  HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
     // Shift right cannot be mapped to the native operator easily.    
     return null;
   }
 
-  HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
-    throw 'Shift right has no builtin variant';
-  }
-
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.shiftRight;
   }
 }
 
 class BitOrSpecializer extends BinaryBitOpSpecializer {
   const BitOrSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.bitOr;
@@ skipping 159 matching lines @@
   const LessEqualSpecializer();
 
   BinaryOperation operation(ConstantSystem constantSystem) {
     return constantSystem.lessEqual;
   }
 
   HInstruction newBuiltinVariant(HInstruction left, HInstruction right) {
     return new HLessEqual(left, right);
   }
 }