Merge TRUNCDIV and MOD into one instruction. Icorporated feedback from CL https://codereview.chromi…

tests/language/modulo_test.dart

Index: tests/language/modulo_test.dart
===================================================================
--- tests/language/modulo_test.dart	(revision 30526)
+++ tests/language/modulo_test.dart	(working copy)
@@ -8,26 +8,57 @@
 
 
 main() {
+  // Prime IC cache.
+  noDom(1);
+  noDom(-1);
   for (int i = -30; i < 30; i++) {
     Expect.equals(i % 256, foo(i));
     Expect.equals(i % -256, boo(i));
-    try {
-      hoo(i);
-      Expect.fail("Exception expected.");
-    } catch (e) {}
+    Expect.throws(() => hoo(i), (e) => e is IntegerDivisionByZeroException);
+    
+    Expect.equals(i ~/ 254 + i % 254, fooTwo(i));
+    Expect.equals(i ~/ -254 + i % -254, booTwo(i));
+    Expect.throws(() => hooTwo(i), (e) => e is IntegerDivisionByZeroException);
+    if (i > 0) {
+      Expect.equals(i % 10, noDom(i));
+    } else {
+      Expect.equals(i ~/ 10, noDom(i));
+    }
+    Expect.equals((i ~/ 10) + (i ~/ 10) + (i % 10), threeOp(i));
+    Expect.equals((i ~/ 10) + (i ~/ 12) + (i % 10) + (i % 12), fourOp(i));
   }
 }
 
-foo(i) {
-  return i % 256;  // This will get optimized to AND instruction.
-}
+foo(i) => i % 256;  // This will get optimized to AND instruction.
+boo(i) => i % -256;
+hoo(i) => i % 0;
 
+fooTwo(i) => i ~/ 254 + i % 254;
+booTwo(i) => i ~/ -254 + i % -254;
+hooTwo(i) => i ~/ 0 + i % 0;
 
-boo(i) {
-  return i % -256;
+noDom(a) {
+  var x;
+  if (a > 0) {
+    x = a % 10;
+  } else {
+    x = a ~/ 10;
+  }
+  return x;
 }
 
+threeOp(a) {
+  var x = a ~/ 10;
+  var y = a ~/ 10;
+  var z = a % 10;
+  return x + y + z;
+}
 
-hoo(i) {
-  return i % 0;
-}
+
+fourOp(a) {
+  var x0 = a ~/ 10;
+  var x1 = a ~/ 12;
+  var y0 = a % 10; 
+  var y1 = a % 12;
+  return x0 + x1 + y0 + y1;
+}