blob: 67acd90fa890e069332b6d4342f096e44b57da8c [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 negative opportunities for dead loop removal.
function loop1() {
while (true) return;
}
function loop2() {
var i = 0;
while (i++ < 10) ;
return i; // value of {i} escapes.
// can only remove the loop with induction variable analysis.
}
function loop3() {
var i = 0;
for (; i < 10; i++) ;
return i; // value of {i} escapes.
// can only remove the loop with induction variable analysis.
}
function loop4() {
var a = 0;
for (var i = 0; i < 10; i++) a++;
return a; // value of {a} escapes.
// can only remove the loop with induction variable analysis.
}
function loop5() {
var a = new Int32Array(4), sum = 0;
for (var i = 0; i < a.length; i++) {
sum += a[i];
}
return sum; // {sum} escapes.
// can only remove the loop by figuring out that all elements of {a} are 0.
}
function loop6(a) {
for (var i = 0; i < a; i++) ; // implicit a.valueOf().
// can only remove the loop by guarding on the type of a.
}
function loop7(a) {
for (var i = 0; i < 10; i++) a.toString(); // unknown side-effect on a.
// can only remove the loop by guarding on the type of a.
}
function loop8(a) {
for (var i = 0; i < 10; i++) a.valueOf(); // unknown side-effect on a.
// can only remove the loop by guarding on the type of a.
}
var no_params_loops = [loop1, loop2, loop3, loop4, loop5, loop6];
var params_loops = [loop6, loop7, loop8];
for (var i = 0; i < no_params_loops.length; i++) {
var f = no_params_loops[i];
%PrepareFunctionForOptimization(f);
f();
f();
f();
%OptimizeFunctionOnNextCall(f);
f();
}
for (var i = 0; i < params_loops.length; i++) {
var f = params_loops[i];
%PrepareFunctionForOptimization(f);
f(3);
f(7);
f(11);
%OptimizeFunctionOnNextCall(f);
f(9);
}