On Thu, 17 Apr 2025 00:08:55 GMT, Chen Liang <li...@openjdk.org> wrote:
> The downcallHandle method in Linker has a complex implementation, and type > switches is triggered in multiple places in that handle. > > After bytestacks analysis of a simple program that links the native > implementation of Class::forName0, it turns out that: > 1. there are a few missed usages of type switch in ClassFile API > 2. type switch can speed up generation by using explicit stack maps, as stack > map gen is over 50% of the generation instructions because the switch is > branch-heavy, but the frames are actually simple. > > These two combined are not that significant in the overall overhead of > downcallHandle, but would be helpful for other workloads. This pull request has now been integrated. Changeset: bd1c53e9 Author: Chen Liang <li...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/bd1c53e96038994788ca5c11602aa2ce4fa4c840 Stats: 47 lines in 2 files changed: 34 ins; 2 del; 11 mod 8354899: Reduce overhead associated with type switches Reviewed-by: asotona ------------- PR: https://git.openjdk.org/jdk/pull/24705
