Handling expression decomposition and array bounds check hoisting: working code with lots of debugg…

test/mjsunit/array-bounds-check-removal.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // 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
@@ skipping 184 matching lines @@
 var result_phi = 0;
 result_phi = test_phi(data_phi, 3,  true);
 assertEquals(12, result_phi);
 result_phi = test_phi(data_phi, 3,  true);
 assertEquals(12, result_phi);
 %OptimizeFunctionOnNextCall(test_phi);
 result_phi = test_phi(data_phi, 3,  true);
 assertEquals(12, result_phi);
 
 
+// A test for recursive decomposition
+var data_composition_long = [0, 1, 2, 3, 4, 5, 6, 7, 8];
+var data_composition_short = [0, 1, 2, 3, 4];
+function test_composition(a, base0, check) {
+  var base1 = ((base0 + 2));
+  var base2 = ((base1 + 8) >> 2);
+  var base3 = ((base2 + 6) >> 1);
+  var base4 = ((base3 + 8) >> 1);
+  
+  var result = 0;
+  result += a[base0];
+  result += a[base1];
+  result += a[base2];
+  result += a[base3];
+  result += a[base4];
+
+  if (false) {

[Jakob Kummerow, 2013/03/14 16:18:16]

debugging leftover?

+    print("base0: " + base0 +
+        ", base1: " + base1 +
+        ", base2: " + base2 +
+        ", base3: " + base3 +
+        ", base4: " + base4 +
+        ", result: " + result +
+        ", length: " + a.length);
+  }
+  
+  return result;
+}
+var result_composition = 0;
+result_composition = test_composition(data_composition_long, 2);
+assertEquals(19, result_composition);
+result_composition = test_composition(data_composition_long, 2);
+assertEquals(19, result_composition);
+%OptimizeFunctionOnNextCall(test_composition);
+result_composition = test_composition(data_composition_short, 2);
+assertEquals(NaN, result_composition);
+
+
 gc();