[Webkit-unassigned] [Bug 201633] New: [JSC] Remove CheckAdd in JetStream2/async-fs's Math.random function

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=201633

            Bug ID: 201633
           Summary: [JSC] Remove CheckAdd in JetStream2/async-fs's
                    Math.random function
           Product: WebKit
           Version: WebKit Nightly Build
          Hardware: Unspecified
                OS: Unspecified
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: JavaScriptCore
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: ysuzuki at apple.com

Math.random function implementation in async-fs repeatedly emits CheckAdd.
And this makes PutGlobalVariable un-sunkable, and bloats many code that is not inherently necessary.

 35     return function() {
 36         // Robert Jenkins' 32 bit integer hash function.
 37         seed = ((seed + 0x7ed55d16) + (seed << 12))  & 0xffffffff;
 38         seed = ((seed ^ 0xc761c23c) ^ (seed >>> 19)) & 0xffffffff;
 39         seed = ((seed + 0x165667b1) + (seed << 5))   & 0xffffffff;
 40         seed = ((seed + 0xd3a2646c) ^ (seed << 9))   & 0xffffffff;
 41         seed = ((seed + 0xfd7046c5) + (seed << 3))   & 0xffffffff;
 42         seed = ((seed ^ 0xb55a4f09) ^ (seed >>> 16)) & 0xffffffff;
 43         return (seed & 0xfffffff) / 0x10000000;
 44     };

But seems that `& 0xffffffff` is saying that we only care lower 32bit. I would like to check how to remove the above check-add and make this efficient.

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