blob: 878f90841a7ec7430ad9b8aeccbbc829b9a20ba5 [file] [log] [blame]
// Copyright 2013 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: --allow-natives-syntax
// Presents opportunities for dead loop removal.
function loop1() {
while (false) ; // doesn't even loop.
}
function loop2() {
var i = 0;
while (i++ < 10) ; // nothing in the body.
}
function loop3() {
for (var i = 0; i < 10; i++) ; // nothing in the body.
}
function loop4() {
var a = 0;
for (var i = 0; i < 10; i++) a++; // {a} is dead after the loop.
}
function loop5() {
var a = new Int32Array(4), sum = 0;
for (var i = 0; i < a.length; i++) {
// Involves only reads on typed arrays, and {i} doesn't overflow.
sum += a[i];
}
}
function loop6() {
var a = new Array(4), sum = 0;
for (var i = 0; i < a.length; i++) {
// Involves only in-bounds read on the array {a}.
// Have to prove that {a} doesn't have getters...?
sum += a[i];
}
}
function loop7() {
for (var i = 0; i < 10; i++) {
new Object(); // Have to prove the allocation doesn't escape.
}
}
function loop8() {
for (var i = 0; i < 10; i++) {
var x = {}; // Have to prove the allocation doesn't escape.
}
}
var loops = [loop1, loop2, loop3, loop4, loop5, loop6, loop7, loop8];
for (var i = 0; i < loops.length; i++) {
var f = loops[i];
%PrepareFunctionForOptimization(f);
f();
f();
%OptimizeFunctionOnNextCall(f);
f();
}