Add some test cases with dead loops.

test/mjsunit/compiler/dead-loops-neg.js

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 // Flags: --allow-natives-syntax
 
-// Test usage of static type information for loads that would otherwise
-// turn into polymorphic or generic loads.
+// Presents negative opportunities for dead loop removal.
 
-// Prepare a highly polymorphic load to be used by all tests.
-Object.prototype.load = function() { return this.property; };
-Object.prototype.load.call({ A:0, property:10 });
-Object.prototype.load.call({ A:0, B:0, property:11 });
-Object.prototype.load.call({ A:0, B:0, C:0, property:12 });
-Object.prototype.load.call({ A:0, B:0, C:0, D:0, property:13 });
-Object.prototype.load.call({ A:0, B:0, C:0, D:0, E:0, property:14 });
-Object.prototype.load.call({ A:0, B:0, C:0, D:0, E:0, F:0, property:15 });
+function loop1() {
+  while (true) return;
+}
 
-// Test for object literals.
-(function() {
-  function f(x) {
-    var object = { property:x };
-    return object.load();
+function loop2() {
+  var i = 0;
+  while (i++ < 10) ;
+  return i;  // value of {i} escapes.
+  // can only remove the loop with induction variable analysis.
+}
+
+function loop3() {
+  var i = 0;
+  for (; i < 10; i++) ;
+  return i;  // value of {i} escapes.
+  // can only remove the loop with induction variable analysis.
+}
+
+function loop4() {
+  var a = 0;
+  for (var i = 0; i < 10; i++) a++;
+  return a;  // value of {a} escapes.
+  // can only remove the loop with induction variable analysis.
+}
+
+function loop5() {
+  var a = new Int32Array(4), sum = 0;
+  for (var i = 0; i < a.length; i++) {
+    sum += a[i];
   }
+  return sum;  // {sum} escapes.
+  // can only remove the loop by figuring out that all elements of {a} are 0.
+}
 
-  assertSame(1, f(1));
-  assertSame(2, f(2));
+function loop6(a) {
+  for (var i = 0; i < a; i++) ;  // implicit a.valueOf().
+  // can only remove the loop by guarding on the type of a.
+}
+
+function loop7(a) {
+  for (var i = 0; i < 10; i++) a.toString();  // unknown side-effect on a.
+  // can only remove the loop by guarding on the type of a.
+}
+
+function loop8(a) {
+  for (var i = 0; i < 10; i++) a.valueOf();  // unknown side-effect on a.
+  // can only remove the loop by guarding on the type of a.
+}
+
+var no_params_loops = [loop1, loop2, loop3, loop4, loop5, loop6];
+var params_loops = [loop6, loop7, loop8];
+
+for (var i = 0; i < no_params_loops.length; i++) {
+  var f = no_params_loops[i];
+  f();
+  f();
+  f();
   %OptimizeFunctionOnNextCall(f);
-  assertSame(3, f(3));
-})();
+  f();
+}
 
-// Test for inlined constructors.
-(function() {
-  function c(x) {
-    this.property = x;
-  }
-  function f(x) {
-    var object = new c(x);
-    return object.load();
-  }
-
-  assertSame(1, f(1));
-  assertSame(2, f(2));
+for (var i = 0; i < params_loops.length; i++) {
+  var f = params_loops[i];
+  f(3);
+  f(7);
+  f(11);
   %OptimizeFunctionOnNextCall(f);
-  assertSame(3, f(3));
-})();
+  f(9);
+}