v8/test/mjsunit/compiler/short-circuit.js
kmillikin@chromium.org 9095abb776 Introduce 'top-of-stack caching' to the toplevel code generator by
allowing the value of the rightmost subexpressions to be evaluated
into an accumulator register (eg, eax, rax, or r0) rather than onto
the stack.

Review URL: http://codereview.chromium.org/541047

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3630 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2010-01-18 14:04:55 +00:00

103 lines
4.1 KiB
JavaScript

// 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,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// 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; }());