This is fundamentally an 68K instruction emulator. Tracked the issue to MacroAssemblerARM64.h where we inadvertently use the destination register for both the source and destination in two arg or64(), eor32( ) and eor64().
Created attachment 230111 [details] Patch
Comment on attachment 230111 [details] Patch r=me. Is it possible to write a test?
(In reply to comment #2) > (From update of attachment 230111 [details]) > r=me. Is it possible to write a test? I think so. I'll spend some time to see if I can come up with one.
Created attachment 230118 [details] Patch with test added
Comment on attachment 230118 [details] Patch with test added r=me
Committed r167782: <http://trac.webkit.org/changeset/167782>