On Thu, 25 Jun 2026 11:18:19 GMT, Joel Sikström <[email protected]> wrote:
>> Hello, >> >> This is (yet another) cleanup to remove redundant memory barriers after the >> new ValuePayload abstraction API in the runtime. The ValuePayload API's >> (including FlatValuePayload::read) does the necessary calls to order stores >> of the copy before the oop is published (OrderAccess::storestore), making >> the platform-specific memory barriers redundant. >> >> I don't have hardware access to RISCV or PPC, but looking at the runtime >> implementations of OrderAccess::storestore, they achieve the same thing as >> the platform-specific memory barriers that I suggest we remove in this PR. >> ~~GHA will show that this compiles at least.~~ Edit: looks like >> linux-cross-compile is not enabled for the lworld branch yet. >> >> `membar(Assembler::StoreStore | Assembler::LoadLoad);` and >> `OrderAccess::storestore()` both boil down to `lwsync` on PPC. >> >> The C1 call to `load_flat_array` already omits the memory barrier, so we >> don't need to remove it here. >> >> Testing: >> * Oracle's tier1-3 linux-aarch64 >> * GHA >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Joel Sikström has updated the pull request incrementally with one additional > commit since the last revision: > > Add twi_0 + isync after read_flat_field in templateTable_ppc_64.cpp > > Co-authored-by: Martin Doerr <[email protected]> LGTM ------------- Marked as reviewed by fparain (Committer). PR Review: https://git.openjdk.org/valhalla/pull/2581#pullrequestreview-4572725672
