LLVM 3.6.0 is released on 27th Feb 2015 and the necessary x86_64 patches for FTL JIT is included in it. Unfortunately the AArch64 patches aren't yet upstreamed and FTL JIT doesn't work at all with LLVM 3.6 on AArch64 Linux now. (stuck in an infinite loop) But after http://trac.webkit.org/changeset/182483 it would be great to switch to LLVM 3.6 to get better performance and decrease maintenance cost.
Created attachment 250518 [details] Patch It works on X86_64, but we should fix AArch64 before landing it.
gdb backtrace: #0 0x000000200718fc08 in llvm::RuntimeDyldELF::resolveAArch64Relocation(llvm::SectionEntry const&, unsigned long, unsigned long, unsigned int, long) () from /home/oszi/jsc-tests/jsc-stress-results/.vm/JavaScriptCore.framework/Resources/libllvmForJSC.so #1 0x0000002007184bb4 in llvm::RuntimeDyldImpl::resolveRelocationList(llvm::SmallVector<llvm::RelocationEntry, 64u> const&, unsigned long) () from /home/oszi/jsc-tests/jsc-stress-results/.vm/JavaScriptCore.framework/Resources/libllvmForJSC.so #2 0x0000002007184bb4 in llvm::RuntimeDyldImpl::resolveRelocationList(llvm::SmallVector<llvm::RelocationEntry, 64u> const&, unsigned long) () from /home/oszi/jsc-tests/jsc-stress-results/.vm/JavaScriptCore.framework/Resources/libllvmForJSC.so ... #XXXXX (endless stack trace)
Comment on attachment 250518 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=250518&action=review > Tools/efl/jhbuild.modules:150 > + <patch file="llvm-elf-add-stackmaps-aarch64.patch" strip="1"/> > + <patch file="llvm-elf-allow-fde-references-outside-the-2gb-range-aarch64.patch" strip="1"/> Have these patches been proposed upstream?
(In reply to comment #3) > Comment on attachment 250518 [details] > Patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=250518&action=review > > > Tools/efl/jhbuild.modules:150 > > + <patch file="llvm-elf-add-stackmaps-aarch64.patch" strip="1"/> http://reviews.llvm.org/D8258 > > + <patch file="llvm-elf-allow-fde-references-outside-the-2gb-range-aarch64.patch" strip="1"/> http://reviews.llvm.org/D8257 > Have these patches been proposed upstream? I submitted them, but these aren't my patches and I don't have any llvm skill and any time to start to learn llvm and learn how to write llvm tests in the following months. So I can't guaranteee if these tests will be landed in the near future. Additionally we have one more bug in LLVM or WebKit which makes LLVM stuck in an infinite loop. I don't think if we can allocate anybody to work on it in the near future. So let's try to make FTL work on x86_64 first, and maybe we can do it on AArch64 too later. ( maybe H2, maybe next year ... )
FTL JIT works fine with LLVM 3.6.0 release out of the box on X86_64, but has still issues on AArch64. Let's bump LLVM version for X86_64 only for now.
Created attachment 250913 [details] Patch
Comment on attachment 250913 [details] Patch Thanks, rs=me.
Comment on attachment 250913 [details] Patch Clearing flags on attachment: 250913 Committed r182885: <http://trac.webkit.org/changeset/182885>
All reviewed patches have been landed. Closing bug.