dart2js: Constant folding and specialization for remainder

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

Index: pkg/compiler/lib/src/ssa/value_range_analyzer.dart
diff --git a/pkg/compiler/lib/src/ssa/value_range_analyzer.dart b/pkg/compiler/lib/src/ssa/value_range_analyzer.dart
index 1882fc6bb1f65d2ee84d7735a1589c1c95b19af2..589086fac5a39d5aff7fe19aaff80c70793e2631 100644
--- a/pkg/compiler/lib/src/ssa/value_range_analyzer.dart
+++ b/pkg/compiler/lib/src/ssa/value_range_analyzer.dart
@@ -687,7 +687,7 @@ class SsaValueRangeAnalyzer extends HBaseVisitor implements OptimizationPhase {
     }
     if (constantNum.isPositiveInfinity || constantNum.isNegativeInfinity) {
       return info.newUnboundRange();
-    }
+   }
     if (constantNum.isMinusZero) constantNum = new IntConstantValue(0);
     Value value = info.newIntValue(constantNum.primitiveValue);
     return info.newNormalizedRange(value, value);
@@ -832,6 +832,21 @@ class SsaValueRangeAnalyzer extends HBaseVisitor implements OptimizationPhase {
     return info.newUnboundRange();
   }
 
+  Range visitRemainder(HRemainder instruction) {
+    HInstruction left = instruction.inputs[0];
+    HInstruction right = instruction.inputs[1];
+    if (left.isPositiveInteger(compiler) && right.isPositiveInteger(compiler)) {
+      Range divisor = ranges[right];
+      if (divisor != null) {
+        if (divisor.isPositive) {
+          return info.newNormalizedRange(
+              info.intZero, divisor.upper - info.intOne);
+        }
+      }
+    }
+    return info.newUnboundRange();
+  }
+
   Range visitInvokeDynamicMethod(HInvokeDynamicMethod invoke) {
     if ((invoke.inputs.length == 3) && (invoke.selector.name == "%"))
       return handleInvokeModulo(invoke);