Version 1.5.7

dart/sdk/lib/_internal/compiler/implementation/ssa/value_range_analyzer.dart

 // 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.
 
 part of ssa;
 
 
 class ValueRangeInfo {
   final ConstantSystem constantSystem;
 
@@ skipping 756 matching lines @@
     BinaryOperation operation = relational.operation(constantSystem);
     Range rightRange = ranges[relational.right];
     Range leftRange = ranges[relational.left];
 
     if (relational is HIdentity) {
       handleEqualityCheck(relational);
     } else if (operation.apply(leftRange, rightRange)) {
       relational.block.rewrite(
           relational, graph.addConstantBool(true, compiler));
       relational.block.remove(relational);
-    } else if (reverseOperation(operation).apply(leftRange, rightRange)) {
+    } else if (negateOperation(operation).apply(leftRange, rightRange)) {
       relational.block.rewrite(
           relational, graph.addConstantBool(false, compiler));
       relational.block.remove(relational);
     }
     return info.newUnboundRange();
   }
 
   void handleEqualityCheck(HRelational node) {
     Range right = ranges[node.right];
     Range left = ranges[node.left];
@@ skipping 90 matching lines @@
     HRangeConversion newInstruction =
         new HRangeConversion(instruction, backend.intType);
     conversions.add(newInstruction);
     cursor.block.addBefore(cursor, newInstruction);
     // Update the users of the instruction dominated by [cursor] to
     // use the new instruction, that has an narrower range.
     instruction.replaceAllUsersDominatedBy(cursor, newInstruction);
     return newInstruction;
   }
 
-  static BinaryOperation reverseOperation(BinaryOperation operation) {
+  static BinaryOperation negateOperation(BinaryOperation operation) {
     if (operation == const LessOperation()) {
       return const GreaterEqualOperation();
     } else if (operation == const LessEqualOperation()) {
       return const GreaterOperation();
     } else if (operation == const GreaterOperation()) {
       return const LessEqualOperation();
     } else if (operation == const GreaterEqualOperation()) {
       return const LessOperation();
     } else {
       return null;
     }
   }
 
+  static BinaryOperation flipOperation(BinaryOperation operation) {
+    if (operation == const LessOperation()) {
+      return const GreaterOperation();
+    } else if (operation == const LessEqualOperation()) {
+      return const GreaterEqualOperation();
+    } else if (operation == const GreaterOperation()) {
+      return const LessOperation();
+    } else if (operation == const GreaterEqualOperation()) {
+      return const LessEqualOperation();
+    } else {
+      return null;
+    }
+  }
+
   Range computeConstrainedRange(BinaryOperation operation,
                                 Range leftRange,
                                 Range rightRange) {
     Range range;
     if (operation == const LessOperation()) {
       range = info.newNormalizedRange(
           const MinIntValue(), rightRange.upper - info.intOne);
     } else if (operation == const LessEqualOperation()) {
       range = info.newNormalizedRange(const MinIntValue(), rightRange.upper);
     } else if (operation == const GreaterOperation()) {
@@ skipping 13 matching lines @@
     if (condition is !HRelational) return info.newUnboundRange();
     if (condition is HIdentity) return info.newUnboundRange();
     HInstruction right = condition.right;
     HInstruction left = condition.left;
     if (!left.isInteger(compiler)) return info.newUnboundRange();
     if (!right.isInteger(compiler)) return info.newUnboundRange();
 
     Range rightRange = ranges[right];
     Range leftRange = ranges[left];
     Operation operation = condition.operation(constantSystem);
-    Operation reverse = reverseOperation(operation);
+    Operation mirrorOp = flipOperation(operation);
     // Only update the true branch if this block is the only
     // predecessor.
     if (branch.trueBranch.predecessors.length == 1) {
       assert(branch.trueBranch.predecessors[0] == branch.block);
       // Update the true branch to use narrower ranges for [left] and
       // [right].
       Range range = computeConstrainedRange(operation, leftRange, rightRange);
       if (leftRange != range) {
         HInstruction instruction =
             createRangeConversion(branch.trueBranch.first, left);
         ranges[instruction] = range;
       }
 
-      range = computeConstrainedRange(reverse, rightRange, leftRange);
+      range = computeConstrainedRange(mirrorOp, rightRange, leftRange);
       if (rightRange != range) {
         HInstruction instruction =
             createRangeConversion(branch.trueBranch.first, right);
         ranges[instruction] = range;
       }
     }
 
     // Only update the false branch if this block is the only
     // predecessor.
     if (branch.falseBranch.predecessors.length == 1) {
       assert(branch.falseBranch.predecessors[0] == branch.block);
+      Operation reverse = negateOperation(operation);
+      Operation reversedMirror = flipOperation(reverse);
       // Update the false branch to use narrower ranges for [left] and
       // [right].
       Range range = computeConstrainedRange(reverse, leftRange, rightRange);
       if (leftRange != range) {
         HInstruction instruction =
             createRangeConversion(branch.falseBranch.first, left);
         ranges[instruction] = range;
       }
 
-      range = computeConstrainedRange(operation, rightRange, leftRange);
+      range = computeConstrainedRange(reversedMirror, rightRange, leftRange);
       if (rightRange != range) {
         HInstruction instruction =
             createRangeConversion(branch.falseBranch.first, right);
         ranges[instruction] = range;
       }
     }
 
     return info.newUnboundRange();
   }
 
@@ skipping 69 matching lines @@
   }
 
   Range handleBinaryOperation(HBinaryArithmetic instruction) {
     Range leftRange = visit(instruction.left);
     Range rightRange = visit(instruction.right);
     if (leftRange == null || rightRange == null) return null;
     BinaryOperation operation = instruction.operation(info.constantSystem);
     return operation.apply(leftRange, rightRange);
   }
 }