Bug 179024 - [ARM64][Linux] ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default is failing
Summary: [ARM64][Linux] ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.d...
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks: 108645
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Reported: 2017-10-30 11:56 PDT by Zan Dobersek
Modified: 2017-10-30 11:56 PDT (History)
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Description Zan Dobersek 2017-10-30 11:56:13 PDT 
The ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default JSC test is failing on ARM64 Linux configurations:

ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default: DIFF FAILURE!
ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default: --- ../.tests/ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.baseline	2017-10-30 11:54:21.000000000 -0700
ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default: +++ ../ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default.out	2017-10-30 11:54:35.423374816 -0700
ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default: @@ -1 +1,2 @@
ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default: +57:" Base 34 number "	failed Actual:24661871785383064000 Excpected:24661871785383068000
ChakraCore.yaml/ChakraCore/test/GlobalFunctions/ParseInt1.js.default:  Done

TL;DR: parseInt() implementation generates a fmadd instruction that skewers the floating-point accuracy to the point that this failure occurs. More about it at a later point.