Introduce 'top-of-stack caching' to the toplevel code generator by...

test/mjsunit/compiler/short-circuit.js

+// Copyright 2009 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.
+
+// Test some expression contexts involving short-circuit boolean
+// operations that did not otherwise have test coverage.
+
+
+var x = 42;
+
+// Literals in value/test context.
+assertEquals(x, function () { return 0 || x }());
+assertEquals(1, function () { return 1 || x }());
+
+// Literals in test/value context.
+assertEquals(0, function () { return 0 && x }());
+assertEquals(x, function () { return 1 && x }());
+
+// A value on top of the stack in value/test context.
+assertEquals(x, function(y) { return y++ || x }(0));
+assertEquals(1, function(y) { return y++ || x }(1));
+
+// A value on top of the stack in a test/value context.
+assertEquals(0, function(y) { return y++ && x }(0));
+assertEquals(x, function(y) { return y++ && x }(1));
+
+// An object literal in value context.
+assertEquals(0, function () { return {x: 0}}().x);
+
+// An object literal in value/test context.
+assertEquals(0, function () { return {x: 0} || this }().x);
+
+// An object literal in test/value context.
+assertEquals(x, function () { return {x: 0} && this }().x);
+
+// An array literal in value/test context.
+assertEquals(0, function () { return [0,1] || new Array(x,1) }()[0]);
+
+// An array literal in test/value context.
+assertEquals(x, function () { return [0,1] && new Array(x,1) }()[0]);
+
+// Slot assignment in value/test context.
+assertEquals(x, function (y) { return (y = 0) || x }("?"));
+assertEquals(1, function (y) { return (y = 1) || x }("?"));
+
+// Slot assignment in test/value context.
+assertEquals(0, function (y) { return (y = 0) && x }("?"));
+assertEquals(x, function (y) { return (y = 1) && x }("?"));
+
+// void in value context.
+assertEquals(void 0, function () { return void x }());
+
+// void in value/test context.
+assertEquals(x, function () { return (void x) || x }());
+
+// void in test/value context.
+assertEquals(void 0, function () { return (void x) && x }());
+
+// Unary not in value context.
+assertEquals(false, function () { return !x }());
+
+// Unary not in value/test context.
+assertEquals(true, function (y) { return !y || x }(0));
+assertEquals(x, function (y) { return !y || x }(1));
+
+// Unary not in test/value context.
+assertEquals(x, function (y) { return !y && x }(0));
+assertEquals(false, function (y) { return !y && x }(1));
+
+// Comparison in value context.
+assertEquals(false, function () { return x < x; }());
+
+// Comparison in value/test context.
+assertEquals(x, function () { return x < x || x; }());
+assertEquals(true, function () { return x <= x || x; }());
+
+// Comparison in test/value context.
+assertEquals(false, function () { return x < x && x; }());
+assertEquals(x, function () { return x <= x && x; }());