[Webkit-unassigned] [Bug 232753] New: Differential testing: miscomputation of "in" statement

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=232753

            Bug ID: 232753
           Summary: Differential testing: miscomputation of "in" statement
           Product: WebKit
           Version: WebKit Local Build
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: JavaScriptCore
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: lukas.bernhard at rub.de

During differential testing of webkit I found a sample triggering a miscomputation in FTL related to evaluating the "in" statement in an async context.

The sample is invoked as:
WebKitBuild/Release/bin/jsc --validateOptions=true --useConcurrentJIT=false --useConcurrentGC=false --thresholdForJITSoon=10 --thresholdForJITAfterWarmUp=10 --thresholdForOptimizeAfterWarmUp=100 --thresholdForOptimizeAfterLongWarmUp=100 --thresholdForOptimizeSoon=100 --thresholdForFTLOptimizeAfterWarmUp=1000 --thresholdForFTLOptimizeSoon=1000 --validateBCE=true --useFTLJIT=true sample.js

function main() {
    let v249;
    let v205 = "abc".repeat(18) + "\n" +
`aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaabbbbbbbbbbbbbbbaaaaa
aa  setFloat64(v190,v191,aa92) a
bbbbaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaanaaaaaaaaaaaaaa
baaaaabbbaaaaanaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1`

    for (const v223 of v205) {
        const v232 = {};

        v232[v223] = "n";
        async function v244() {
            v249 = "1" in v232;
        }
        const v252 = v244();
    }

    print(v249); // prints true in FTL (an spidermonkey), false in baseline
}
main();

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20211105/2f344e28/attachment.htm>