dfg-cfg-simplify-eliminate-set-local-type-check-then-typeof.js 2.15 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
// Copyright 2013 the V8 project authors. All rights reserved.
// Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1.  Redistributions of source code must retain the above copyright
//     notice, this list of conditions and the following disclaimer.
// 2.  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.
//
// THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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.

description(
"Tests what happens when CFG simplification leads to the elimination of a set local that had a type check, and then we do a typeof on the value, which can be constant folded if the type check stays."
);

function foo(o) {
    var x;
    if (o.f)
        x = o.g;
    else
        x = o.h;
    return [typeof x, x - 1];
}

for (var i = 0; i < 500; ++i) {
    var o = {f:foo};
    var expectedFirst;
    var expectedSecond;
    if (i < 450) {
        o.g = i;
        expectedFirst = "\"number\"";
        expectedSecond = "" + (i - 1);
    } else {
        o.g = "42";
        expectedFirst = "\"string\"";
        expectedSecond = "41";
    }
    var result = foo(o);
    shouldBe("result[0]", expectedFirst);
    shouldBe("result[1]", expectedSecond);
}