Bug 239757

Summary: Wrong JIT compilation
Product: WebKit Reporter: zhunkibatu
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: mark.lam, saam, webkit-bug-importer, ysuzuki
Priority: P2 Keywords: InRadar
Version: WebKit Local Build   
Hardware: PC   
OS: Linux   
Attachments:
Description Flags
the minimal poc none

Description zhunkibatu 2022-04-25 22:46:43 PDT
Created attachment 458332 [details]
the minimal poc

The following PoC outputs differently before/after JIT compilation.

function opt() {
	const a = [12345678901];
	const b = a[12345];
	const c = () => {
    		try {
        		throw "";
    		} catch(e) {
        		({});
    		}
	};
	const d = c();
	return b;
}

print(opt());//undefined
for(var i=0;i<10000;i++){
	opt();
}
print(opt());//NaN
Comment 1 Radar WebKit Bug Importer 2022-05-02 22:47:13 PDT
<rdar://problem/92652058>