127772 2014-01-28 04:56:09 -0800 Javascript function returns incorrect value after being JIT-compiled 2014-10-07 02:59:11 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) iPhone / iPad iOS 7.0 RESOLVED WORKSFORME P1 Major --- 1 szdy12 webkit-unassigned oldest_to_newest 972874 0 222429 szdy12 2014-01-28 04:56:09 -0800 Created attachment 222429 html page with javascript showing errorenous JIT behavior See attachment. Javascript function 'calc' will be called in a loop. After several iterations its return value will be zero instead of the reference value. The non-jitted function 'calc2' (which is the exact copy of 'calc') returns still the reference value. Actual result on iPad mini (iOS 7.0.4, Safari/9537.53): after 35 iterations the result value will be constant zero. 1039993 1 szdy12 2014-10-07 02:59:11 -0700 Seems to be fixed in iOS 8 Safari 222429 2014-01-28 04:56:09 -0800 2014-01-28 04:56:09 -0800 html page with javascript showing errorenous JIT behavior jit.html text/html 1130 szdy12 PGh0bWw+CjxoZWFkPgo8dGl0bGU+U2FmYXJpIEpJVCBidWc8L3RpdGxlPgo8L2hlYWQ+Cjxib2R5 Pgo8c2NyaXB0PgoidXNlIHN0cmljdCI7CmZ1bmN0aW9uIGxvbmcoaCxsKXsKCXRoaXMuaD1ofDA7 Cgl0aGlzLmw9bHwwOwp9CmZ1bmN0aW9uIGludDJsb25nKGkpewoJcmV0dXJuIG5ldyBsb25nKGk+ PjMxLGl8MCk7Cn07CmZ1bmN0aW9uIHN1YihhLGIpewoJdmFyIGw9KGEubD4+PjApLShiLmw+Pj4w KTsKCXZhciBjPWw8MD8xOjA7CglyZXR1cm4gbmV3IGxvbmcoYS5oLWIuaC1jfDAsbHwwKTsKfTsK CmZ1bmN0aW9uIGNhbGMoYixjKXsKCXZhciByPTE7Cgl2YXIgaTsKCWZvcihpPTB4NDAwMDAwMDA7 IGkgPiBiOyBpID4+PSAxKQoJCTsKCWRvIHsKCQlpZigoYiAmIGkpICE9PSAwKQoJCQlyID0gc3Vi KGludDJsb25nKHIpLCBjKS5sOwoJCWlmKChpID4+PSAxKSA9PT0gMCkKCQkJcmV0dXJuIHI7CgkJ ciA9IHN1YihpbnQybG9uZyhyKSwgYykubDsKCX0gd2hpbGUodHJ1ZSk7Cn07CmZ1bmN0aW9uIGNh bGMyKGIsYyl7CS8vIHNhbWUgYXMgY2FsYygpCgl2YXIgcj0xOwoJdmFyIGk7Cglmb3IoaT0weDQw MDAwMDAwOyBpID4gYjsgaSA+Pj0gMSkKCQk7CglkbyB7CgkJaWYoKGIgJiBpKSAhPT0gMCkKCQkJ ciA9IHN1YihpbnQybG9uZyhyKSwgYykubDsKCQlpZigoaSA+Pj0gMSkgPT09IDApCgkJCXJldHVy biByOwoJCXIgPSBzdWIoaW50MmxvbmcociksIGMpLmw7Cgl9IHdoaWxlKHRydWUpOwp9OwpmdW5j dGlvbiB0ZXN0SklUKCl7Cglkb2N1bWVudC53cml0ZShuYXZpZ2F0b3IudXNlckFnZW50ICsgJzxi cj4nKTsKCXZhciBiID0gMTIzNDU2NzgsIGMgPSBpbnQybG9uZyg4NzY1NDMyMSk7Cgl2YXIgcmVm ID0gY2FsYyhiLGMpLCB2YWw7Cglkb2N1bWVudC53cml0ZSgncmVmOiAnICsgcmVmICsgJzxicj4n KTsKCWZvcih2YXIgaT0wO2k8MTAwO2krKykKCQlpZigodmFsID0gY2FsYyhiLGMpKSAhPT0gcmVm KSB7CgkJCWRvY3VtZW50LndyaXRlKGkgKyAnOiAnICsgdmFsICsgJzw+JyArIHJlZiArICcgbm9u LWppdHRlZDonICsgY2FsYzIoYixjKSArICc8YnI+Jyk7CgkJCWJyZWFrOwoJCX0KCWRvY3VtZW50 LndyaXRlKCdkb25lJyk7Cn0KdGVzdEpJVCgpOwo8L3NjcmlwdD4KPC9ib2R5Pgo=