On Sat, 6 May 2023 05:22:48 GMT, Quan Anh Mai <[email protected]> wrote:
>> Stefan Karlsson has updated the pull request with a new target base due to a >> merge or a rebase. The pull request now contains 917 commits: >> >> - ZGC: Generational >> >> Co-authored-by: Stefan Karlsson <[email protected]> >> Co-authored-by: Per Liden <[email protected]> >> Co-authored-by: Albert Mingkun Yang <[email protected]> >> Co-authored-by: Erik Österlund <[email protected]> >> Co-authored-by: Axel Boldt-Christmas <[email protected]> >> Co-authored-by: Stefan Johansson <[email protected]> >> - UPSTREAM: Introduce check_oop infrastructure to check oops in the oop >> class >> - UPSTREAM: RISCV tmp reg cleanup resolve_jobject >> - CLEANUP: barrierSetNMethod_aarch64.cpp >> - UPSTREAM: Add relaxed add&fetch for aarch64 atomics >> - UPSTREAM: assembler_ppc CMPLI >> >> Co-authored-by: TheRealMDoerr <[email protected]> >> - UPSTREAM: assembler_ppc ANDI >> >> Co-authored-by: TheRealMDoerr <[email protected]> >> - UPSTREAM: Add VMErrorCallback infrastructure >> - Merge branch 'zgc_generational' into zgc_generational_rebase_target >> - Whitespace nit >> - ... and 907 more: https://git.openjdk.org/jdk/compare/705ad7d8...349cf9ae > > src/hotspot/cpu/x86/gc/z/zBarrierSetAssembler_x86.cpp line 483: > >> 481: >> 482: __ lock(); >> 483: __ cmpxchgq(rbx, Address(rcx, 0)); > > `ref_addr` is not necessarily materialised here? I think it is, yes. But we want to ensure it's in a register that isn't rbx or rax. So I figured I'd just force materialize it in rcx and call it a day. It might be possible to micro optimize this further and even use the live information we have gathered to eliminate some of the spilling, but I'd like to hold off on that until we integrate. It's again only for atomics, and also happens at most once per field. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/13771#discussion_r1187216401
