Restrict the syntax that we aggressively optimize.

test/mjsunit/compiler/simple-bailouts.js

+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --fast-compiler
+
+function Test() {
+  this.result = 0;
+  this.x = 0;
+  this.y = 0;
+  this.z = 0;
+}
+var a = 1;
+var b = 2;
+var c = 4;
+var d = 8;
+
+// Test operations expected to stay on the fast path.  Enumerate all binary
+// trees with <= 4 leaves.
+Test.prototype.test0 = function () {
+  this.result = a | b;
+};
+
+Test.prototype.test1 = function() {
+  this.result = (a | b) | c;
+};
+
+Test.prototype.test2 = function() {
+  this.result = a | (b | c);
+};
+
+Test.prototype.test3 = function() {
+  this.result = ((a | b) | c) | d;
+};
+
+Test.prototype.test4 = function() {
+  this.result = (a | (b | c)) | d;
+};
+
+Test.prototype.test5 = function() {
+  this.result = (a | b) | (c | d);
+};
+
+Test.prototype.test6 = function() {
+  this.result = a | ((b | c) | d);
+};
+
+Test.prototype.test7 = function() {
+  this.result = a | (b | (c | d));
+};
+
+// These tests should fail if we bailed out to the beginning of the full
+// code.
+Test.prototype.test8 = function () {
+  // If this.x = 1 and a = 1.1:
+  this.y = this.x | b;  // Should be (1 | 2) == 3.
+  this.x = c;           // Should be 4.
+  this.z = this.x | a;  // Should be (4 | 1.1) == 5.
+};
+
+Test.prototype.test9 = function() {
+  // If this.x = 2 and a = 1.1:
+  this.z = // (14 | 1.1) == 15

[fschneider, 2010/02/09 16:59:10]

I'd align the // vertically in this function as well.

+      (this.x = // (6 | 8) == 14
+           (this.y = // (2 | 4) == 6
+                this.x  // 2
+                | c)    // 4
+            | d) // 8
+       | a;  // 1.0

[fschneider, 2010/02/09 16:59:10]

// 1.1

+}
+
+var t = new Test();
+
+t.test0();
+assertEquals(3, t.result);
+
+t.test1();
+assertEquals(7, t.result);
+t.test2();
+assertEquals(7, t.result);
+
+t.test3();
+assertEquals(15, t.result);
+t.test4();
+assertEquals(15, t.result);
+t.test5();
+assertEquals(15, t.result);
+t.test6();
+assertEquals(15, t.result);
+t.test7();
+assertEquals(15, t.result);
+
+a = 1.1;
+t.x = 1;
+t.test8();
+assertEquals(4, t.x);
+assertEquals(3, t.y);
+assertEquals(5, t.z);
+
+t.x = 2;
+t.test9();
+assertEquals(14, t.x);
+assertEquals(6, t.y);
+assertEquals(15, t.z);