On Mon, 6 Jan 2025 14:12:56 GMT, Coleen Phillimore <cole...@openjdk.org> wrote:
>> Please review this change that makes AccessFlags and modifier_flags u2 types >> and removes the last remnants of Hotspot adding internal access flags. This >> change moves AccessFlags and modifier_flags in Klass to alignment gaps >> saving 16 bytes. From pahole: so it's a bit better. >> >> before: >> >> /* size: 216, cachelines: 4, members: 25, static members: 17 */ >> /* sum members: 194, holes: 3, sum holes: 18 */ >> >> >> after: >> >> /* size: 200, cachelines: 4, members: 25, static members: 17 */ >> /* sum members: 188, holes: 4, sum holes: 12 */ >> >> >> We may eventually move the modifiers to java.lang.Class but that's WIP. >> >> Tested with tier1-7 on oracle platforms. Did test builds on other platforms >> (please try these changes ppc/arm32 and s390). Also requires minor Graal >> changes. > > Coleen Phillimore has updated the pull request incrementally with one > additional commit since the last revision: > > Remove unused SA function. Thank you for update with this an unification! I've posted a couple of comments with similar nits. src/hotspot/share/interpreter/linkResolver.cpp line 586: > 584: // We need to change "protected" to "public". > 585: assert(flags.is_protected(), "clone not protected?"); > 586: u2 new_flags = flags.as_unsigned_short(); Nit: Should this also be replaced with `as_method_flags()`? src/hotspot/share/opto/memnode.cpp line 1985: > 1983: // The field is Klass::_access_flags. Return its (constant) value. > 1984: // (Folds up the 2nd indirection in > Reflection.getClassAccessFlags(aClassConstant).) > 1985: assert(this->Opcode() == Op_LoadUS, "must load an unsigned short > from _access_flags"); Nit: This can be unified with line 1979 and also get rid of `this->`. src/hotspot/share/prims/jvm.cpp line 2472: > 2470: u2 field_access_flags = > InstanceKlass::cast(k)->field_access_flags(field_index); > 2471: // This & should be unnecessary. > 2472: assert((field_access_flags & JVM_RECOGNIZED_FIELD_MODIFIERS) == > field_access_flags, "already masked"); Nit: Yes, it is better to remove the lines: 2471-2472. ------------- PR Review: https://git.openjdk.org/jdk/pull/22246#pullrequestreview-2532540668 PR Review Comment: https://git.openjdk.org/jdk/pull/22246#discussion_r1904386978 PR Review Comment: https://git.openjdk.org/jdk/pull/22246#discussion_r1904405970 PR Review Comment: https://git.openjdk.org/jdk/pull/22246#discussion_r1904404626
