On Tue, 22 Oct 2024 15:37:23 GMT, Andrew Haley <a...@openjdk.org> wrote:
>> Patricio Chilano Mateo has updated the pull request incrementally with six >> additional commits since the last revision: >> >> - Fix comments in objectMonitor.hpp >> - Move frame::saved_thread_address() to platform dependent files >> - Fix typo in jvmtiExport.cpp >> - remove usage of frame::metadata_words in possibly_adjust_frame() >> - Fix comments in c2 locking paths >> - Revert and simplify changes to c1_Runtime1 on aarch64 and riscv > > src/hotspot/cpu/aarch64/c2_MacroAssembler_aarch64.cpp line 60: > >> 58: >> 59: assert(LockingMode != LM_LIGHTWEIGHT, "lightweight locking should use >> fast_lock_lightweight"); >> 60: assert_different_registers(oop, box, tmp, disp_hdr, rscratch2); > > Historically, silently using `rscratch1` and `rscratch2` in these macros has > sometimes turned out to be a mistake. > Please consider making `rscratch2` an additional argument to `fast_lock`, so > that it's explicit in the caller. It won't make any difference to the > generated code, but it might help readbility. Note also that `inc_held_monitor_count` clobbers `rscratch2`. That might be worth a comment at the call site. I guess `inc_held_monitor_count` is so hot that we can't push and pop scratch registers, in which case it'd clobber nothing. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1810985771
