Use JavaScript runtime semantics when constant folding.

lib/compiler/implementation/operations.dart

Index: lib/compiler/implementation/operations.dart
diff --git a/lib/compiler/implementation/operations.dart b/lib/compiler/implementation/operations.dart
deleted file mode 100644
index 0fb34cb6d6513145fab4d2d01d3292855487c744..0000000000000000000000000000000000000000
--- a/lib/compiler/implementation/operations.dart
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@@ -1,309 +0,0 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-interface Operation {
-  final SourceString name;
-  bool isUserDefinable();
-}
-
-interface UnaryOperation extends Operation {
-  /** Returns [:null:] if it was unable to fold the operation. */
-  Constant fold(Constant constant);
-}
-
-class BitNotOperation implements UnaryOperation {
-  final SourceString name = const SourceString('~');
-  bool isUserDefinable() => true;
-  const BitNotOperation();
-  Constant fold(Constant constant) {
-    if (constant.isInt()) {
-      IntConstant intConstant = constant;
-      return new IntConstant(~intConstant.value);
-    }
-    return null;
-  }
-}
-
-class NegateOperation implements UnaryOperation {
-  final SourceString name = const SourceString('negate');
-  bool isUserDefinable() => true;
-  const NegateOperation();
-  Constant fold(Constant constant) {
-    if (constant.isInt()) {
-      IntConstant intConstant = constant;
-      return new IntConstant(-intConstant.value);
-    }
-    if (constant.isDouble()) {
-      DoubleConstant doubleConstant = constant;
-      return new DoubleConstant(-doubleConstant.value);
-    }
-    return null;
-  }
-}
-
-class NotOperation implements UnaryOperation {
-  final SourceString name = const SourceString('!');
-  bool isUserDefinable() => true;
-  const NotOperation();
-  Constant fold(Constant constant) {
-    if (constant.isBool()) {
-      BoolConstant boolConstant = constant;
-      return boolConstant.negate();
-    }
-    return null;
-  }
-}
-
-interface BinaryOperation extends Operation {
-  /** Returns [:null:] if it was unable to fold the operation. */
-  Constant fold(Constant left, Constant right);
-}
-
-/**
- * Operations that only work if both arguments are integers.
- */
-class BinaryIntOperation implements BinaryOperation {
-  bool isUserDefinable() => true;
-  const BinaryIntOperation();
-  Constant fold(Constant left, Constant right) {
-    if (left.isInt() && right.isInt()) {
-      IntConstant leftInt = left;
-      IntConstant rightInt = right;
-      int resultValue = foldInts(leftInt.value, rightInt.value);
-      if (resultValue === null) return null;
-      return new IntConstant(resultValue);
-    }
-    return null;
-  }
-
-  abstract int foldInts(int left, int right);
-}
-
-class BitOrOperation extends BinaryIntOperation {
-  final SourceString name = const SourceString('|');
-  const BitOrOperation();
-  int foldInts(int left, int right)  => left | right;
-}
-
-class BitAndOperation extends BinaryIntOperation {
-  final SourceString name = const SourceString('&');
-  const BitAndOperation();
-  int foldInts(int left, int right) => left & right;
-}
-
-class BitXorOperation extends BinaryIntOperation {
-  final SourceString name = const SourceString('^');
-  const BitXorOperation();
-  int foldInts(int left, int right) => left ^ right;
-}
-
-class ShiftLeftOperation extends BinaryIntOperation {
-  final SourceString name = const SourceString('<<');
-  const ShiftLeftOperation();
-  int foldInts(int left, int right) {
-    // TODO(floitsch): find a better way to guard against excessive shifts to
-    // the left.
-    if (right > 100 || right < 0) return null;
-    return left << right;
-  }
-}
-
-class ShiftRightOperation extends BinaryIntOperation {
-  final SourceString name = const SourceString('>>');
-  const ShiftRightOperation();
-  int foldInts(int left, int right) {
-    if (right < 0) return null;
-    return left >> right;
-  }
-}
-
-class BinaryBoolOperation implements BinaryOperation {
-  bool isUserDefinable() => false;
-  const BinaryBoolOperation();
-  Constant fold(Constant left, Constant right) {
-    if (left.isBool() && right.isBool()) {
-      BoolConstant leftBool = left;
-      BoolConstant rightBool = right;
-      bool resultValue = foldBools(leftBool.value, rightBool.value);
-      return new BoolConstant(resultValue);
-    }
-    return null;
-  }
-
-  abstract bool foldBools(bool left, bool right);
-}
-
-class BooleanAnd extends BinaryBoolOperation {
-  final SourceString name = const SourceString('&&');
-  const BooleanAnd();
-  bool foldBools(bool left, bool right) => left && right;
-}
-
-class BooleanOr extends BinaryBoolOperation {
-  final SourceString name = const SourceString('||');
-  const BooleanOr();
-  bool foldBools(bool left, bool right) => left || right;
-}
-
-class ArithmeticNumOperation implements BinaryOperation {
-  bool isUserDefinable() => true;
-  const ArithmeticNumOperation();
-  Constant fold(Constant left, Constant right) {
-    if (left.isNum() && right.isNum()) {
-      NumConstant leftNum = left;
-      NumConstant rightNum = right;
-      num foldedValue;
-      if (left.isInt() && right.isInt()) {
-        foldedValue = foldInts(leftNum.value, rightNum.value);
-      } else {
-        foldedValue = foldNums(leftNum.value, rightNum.value);
-      }
-      // A division by 0 means that we might not have a folded value.
-      if (foldedValue === null) return null;
-      if (left.isInt() && right.isInt() && !isDivide()) {
-        assert(foldedValue is int);
-        return new IntConstant(foldedValue);
-      } else {
-        return new DoubleConstant(foldedValue);
-      }
-    }
-    return null;
-  }
-
-  bool isDivide() => false;
-  num foldInts(int left, int right) => foldNums(left, right);
-  abstract num foldNums(num left, num right);
-}
-
-class SubtractOperation extends ArithmeticNumOperation {
-  final SourceString name = const SourceString('-');
-  const SubtractOperation();
-  num foldNums(num left, num right) => left - right;
-}
-
-class MultiplyOperation extends ArithmeticNumOperation {
-  final SourceString name = const SourceString('*');
-  const MultiplyOperation();
-  num foldNums(num left, num right) => left * right;
-}
-
-class ModuloOperation extends ArithmeticNumOperation {
-  final SourceString name = const SourceString('%');
-  const ModuloOperation();
-  int foldInts(int left, int right) {
-    if (right == 0) return null;
-    return left % right;
-  }
-  num foldNums(num left, num right) => left % right;
-}
-
-class TruncatingDivideOperation extends ArithmeticNumOperation {
-  final SourceString name = const SourceString('~/');
-  const TruncatingDivideOperation();
-  int foldInts(int left, int right) {
-    if (right == 0) return null;
-    return left ~/ right;
-  }
-  num foldNums(num left, num right) => left ~/ right;
-}
-
-class DivideOperation extends ArithmeticNumOperation {
-  final SourceString name = const SourceString('/');
-  const DivideOperation();
-  num foldNums(num left, num right) => left / right;
-  bool isDivide() => true;
-}
-
-class AddOperation implements BinaryOperation {
-  final SourceString name = const SourceString('+');
-  bool isUserDefinable() => true;
-  const AddOperation();
-  Constant fold(Constant left, Constant right) {
-    if (left.isInt() && right.isInt()) {
-      IntConstant leftInt = left;
-      IntConstant rightInt = right;
-      return new IntConstant(leftInt.value + rightInt.value);
-    } else if (left.isNum() && right.isNum()) {
-      NumConstant leftNum = left;
-      NumConstant rightNum = right;
-      return new DoubleConstant(leftNum.value + rightNum.value);
-    } else {
-      return null;
-    }
-  }
-}
-
-class RelationalNumOperation implements BinaryOperation {
-  bool isUserDefinable() => true;
-  const RelationalNumOperation();
-  Constant fold(Constant left, Constant right) {
-    if (left.isNum() && right.isNum()) {
-      NumConstant leftNum = left;
-      NumConstant rightNum = right;
-      bool foldedValue = foldNums(leftNum.value, rightNum.value);
-      assert(foldedValue != null);
-      return new BoolConstant(foldedValue);
-    }
-  }
-
-  abstract bool foldNums(num left, num right);
-}
-
-class LessOperation extends RelationalNumOperation {
-  final SourceString name = const SourceString('<');
-  const LessOperation();
-  bool foldNums(num left, num right) => left < right;
-}
-
-class LessEqualOperation extends RelationalNumOperation {
-  final SourceString name = const SourceString('<=');
-  const LessEqualOperation();
-  bool foldNums(num left, num right) => left <= right;
-}
-
-class GreaterOperation extends RelationalNumOperation {
-  final SourceString name = const SourceString('>');
-  const GreaterOperation();
-  bool foldNums(num left, num right) => left > right;
-}
-
-class GreaterEqualOperation extends RelationalNumOperation {
-  final SourceString name = const SourceString('>=');
-  const GreaterEqualOperation();
-  bool foldNums(num left, num right) => left >= right;
-}
-
-class EqualsOperation implements BinaryOperation {
-  final SourceString name = const SourceString('==');
-  bool isUserDefinable() => true;
-  const EqualsOperation();
-  Constant fold(Constant left, Constant right) {
-    if (left.isNum() && right.isNum()) {
-      // Numbers need to be treated specially because: NaN != NaN, -0.0 == 0.0,
-      // and 1 == 1.0.
-      NumConstant leftNum = left;
-      NumConstant rightNum = right;
-      return new BoolConstant(leftNum.value == rightNum.value);
-    }
-    if (left.isConstructedObject()) {
-      // Unless we know that the user-defined object does not implement the
-      // equality operator we cannot fold here.
-      return null;
-    }
-    return new BoolConstant(left == right);
-  }
-}
-
-class IdentityOperation implements BinaryOperation {
-  final SourceString name = const SourceString('===');
-  bool isUserDefinable() => false;
-  const IdentityOperation();
-  Constant fold(Constant left, Constant right) {
-    // In order to preserve runtime semantics which says that NaN !== NaN don't
-    // constant fold NaN === NaN. Otherwise the output depends on inlined
-    // variables and other optimizations.
-    if (left.isNaN() && right.isNaN()) return null;
-    return new BoolConstant(left == right);
-  }
-}