189758 2018-09-19 11:26:15 -0700 Packed Variant violates alignment on ARM and MIPS 2018-10-02 09:13:56 -0700 1 1 1 Unclassified WebKit New Bugs WebKit Nightly Build Other Linux RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=188559 P2 Blocker --- 1 dominik.infuehr webkit-unassigned achristensen fujii koivisto oldest_to_newest 1461055 0 dominik.infuehr 2018-09-19 11:26:15 -0700 Hi, recent patch https://bugs.webkit.org/show_bug.cgi?id=188559 broke tests in JSC on ARM and MIPS because data isn't aligned anymore. Not sure what's the best way to fix that: if we should just disable pack'ing on at least ARM and MIPS. 1461312 1 dominik.infuehr 2018-09-20 06:05:00 -0700 Some more additional information: JSC has now 26k test failures due to this change on ARM: https://build.webkit.org/builders/JSCOnly%20Linux%20ARMv7%20Thumb2%20Release. Reason for that is the lexer uses a type std::optional<Variant<double,int*>> which breaks probably all tests (see Source/JavaScriptCore/parser/Lexer.(h|cpp)). 1461331 2 fujii 2018-09-20 07:34:57 -0700 How do you know Lexer is the crash point? Did you get the coredump and the backtrace? 1461753 3 dominik.infuehr 2018-09-21 00:35:34 -0700 I got the backtrace from testing it locally on my board. It also makes sense since the Lexer uses a Variant in an std::optional and the corresponding assembly code fails on storing a floating point register to a memory location that's not 8-byte aligned.