> This is part of changes which try to reduce size of `nmethod` and `codeblob` > data vs code in CodeCache. > These changes reduced size of `nmethod` header from 288 to 232 bytes. From > 304 to 248 in optimized VM: > > Statistics for 1282 bytecoded nmethods for C2: > total in heap = 5560352 (100%) > header = 389728 (7.009053%) > > vs > > Statistics for 1322 bytecoded nmethods for C2: > total in heap = 8307120 (100%) > header = 327856 (3.946687%) > > > Several unneeded fields in `nmethod` and `CodeBlob` were removed. Some fields > were changed from `int` to `int16_t` with added corresponding asserts to make > sure their values are fit into 16 bits. > > I did additional cleanup after recent `CompiledMethod` removal. > > Tested tier1-7,stress,xcomp and performance testing.
Vladimir Kozlov has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains eight commits: - Merge master - remove trailing space - Shuffle fields initialization - Address comments. Used checked_cast. - Use 16-bits types for header_size and frame_complete_offset arguments - Union fields which usages do not overlap - Moved some fields initialization into init_defaults() - 8329433: Reduce nmethod header size ------------- Changes: https://git.openjdk.org/jdk/pull/18768/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18768&range=06 Stats: 528 lines in 15 files changed: 140 ins; 178 del; 210 mod Patch: https://git.openjdk.org/jdk/pull/18768.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/18768/head:pull/18768 PR: https://git.openjdk.org/jdk/pull/18768
