Add a deoptimization count to each function to limit number of re-compilations.

test/mjsunit/assert-opt-and-deopt.js

 // Copyright 2011 the V8 project authors. All rights reserved.

[Jakob Kummerow, 2012/01/16 11:41:25]

nit: 2012

[fschneider, 2012/01/19 10:26:11]

Done.

 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
@@ skipping 15 matching lines @@
 
 // Flags: --allow-natives-syntax
 
 /**
  * This class shows how to use %GetOptimizationCount() and
  * %GetOptimizationStatus() to infer information about opts and deopts.
  * Might be nice to put this into mjsunit.js, but that doesn't depend on
  * the --allow-natives-syntax flag so far.
  */
 function OptTracker() {
-  this.opt_counts_ = {};
+  this.deopt_counts_ = {};
 }
 
 /**
  * The possible optimization states of a function. Must be in sync with the
  * return values of Runtime_GetOptimizationStatus() in runtime.cc!
  * @enum {int}
  */
 OptTracker.OptimizationState = {
     YES: 1,
     NO: 2,
     ALWAYS: 3,
     NEVER: 4
 };
 
 /**
  * Always call this at the beginning of your test, once for each function
  * that you later want to track de/optimizations for. It is necessary because
  * tests are sometimes executed several times in a row, and you want to
  * disregard counts from previous runs.
  */
-OptTracker.prototype.CheckpointOptCount = function(func) {
-  this.opt_counts_[func] = %GetOptimizationCount(func);
+OptTracker.prototype.CheckpointDeoptCount = function(func) {
+  this.deopt_counts_[func] = %GetDeoptimizationCount(func);
 };
 
 OptTracker.prototype.AssertOptCount = function(func, optcount) {
   if (this.DisableAsserts_(func)) {
     return;
   }
   assertEquals(optcount, this.GetOptCount_(func));
 };
 
 OptTracker.prototype.AssertDeoptCount = function(func, deopt_count) {
@@ skipping 23 matching lines @@
     assertEquals(OptTracker.OptimizationState.YES, raw_optimized);
   } else {
     assertEquals(OptTracker.OptimizationState.NO, raw_optimized);
   }
 }
 
 /**
  * @private
  */
 OptTracker.prototype.GetOptCount_ = function(func) {
-  var raw_count = %GetOptimizationCount(func);
-  if (func in this.opt_counts_) {
-    var checkpointed_count = this.opt_counts_[func];
+  var count = this.GetDeoptCount_(func);
+  if (%GetOptimizationStatus(func) == OptTracker.OptimizationState.YES) {
+    count += 1;
+  }
+  return count;
+}
+
+
+/**
+ * @private
+ */
+OptTracker.prototype.GetDeoptCount_ = function(func) {
+  var raw_count = %GetDeoptimizationCount(func);
+  if (func in this.deopt_counts_) {
+    var checkpointed_count = this.deopt_counts_[func];
     return raw_count - checkpointed_count;
   }
   return raw_count;
 }
 
 /**
- * @private
- */
-OptTracker.prototype.GetDeoptCount_ = function(func) {
-  var count = this.GetOptCount_(func);
-  if (%GetOptimizationStatus(func) == OptTracker.OptimizationState.YES) {
-    count -= 1;
-  }
-  return count;
-}
-
-/**
  * @private
  */
 OptTracker.prototype.DisableAsserts_ = function(func) {
   switch(%GetOptimizationStatus(func)) {
     case OptTracker.OptimizationState.YES:
     case OptTracker.OptimizationState.NO:
       return false;
     case OptTracker.OptimizationState.ALWAYS:
     case OptTracker.OptimizationState.NEVER:
       return true;
   }
   return false;
 }
 // (End of class OptTracker.)
 
 // Example function used by the test below.
 function f(a) {
   return a+1;
 }
 
 var tracker = new OptTracker();
-tracker.CheckpointOptCount(f);
+tracker.CheckpointDeoptCount(f);
 
 tracker.AssertOptCount(f, 0);
 tracker.AssertIsOptimized(f, false);
 tracker.AssertDeoptHappened(f, false);
 tracker.AssertDeoptCount(f, 0);
 
 f(1);
 
 %OptimizeFunctionOnNextCall(f);
 f(1);
@@ skipping 13 matching lines @@
 // Let's trigger optimization for another type.
 for (var i = 0; i < 5; i++) f("a");
 
 %OptimizeFunctionOnNextCall(f);
 f("b");
 
 tracker.AssertOptCount(f, 2);
 tracker.AssertIsOptimized(f, true);
 tracker.AssertDeoptHappened(f, true);
 tracker.AssertDeoptCount(f, 1);