> When generating `MethodHandle`-based concatenation expressions in > `StringConcatFactory` we can reduce the number of classes generated at > runtime by creating small batches of prependers and mixers before binding > them into the root expression tree. > > Improvements on one-off tests are modest, while the improvement on > bootstrapping stress tests can be substantial > ([MixedStringCombinations.java](https://gist.github.com/cl4es/08fb581dece3a73e89bfa52337bc4248)): > > | Build | # classes | Runtime | > | ----------- | ----------------- | --------------- | > | Baseline | 31119 | 2.942s | > | Patch | 16208 | 1.958s | > > An earlier version of this patch saw a regression in the > `StringConcatFactoryBootstraps` microbenchmark. After some refactoring along > with the optimizations in #8881 and #8923 that is no longer the case, and > allocation pressure is down slightly compared to the baseline on such a > repeat-the-same-bootstrap stress test: > > Baseline: > > Benchmark Mode Cnt > Score Error Units > SCFB.makeConcatWithConstants avgt 5 > 2170.039 ? 117.441 ns/op > SCFB.makeConcatWithConstants:?gc.alloc.rate.norm avgt 5 > 3538.020 ? 4.558 B/op > > This patch: > > Benchmark Mode Cnt > Score Error Units > SCFB.makeConcatWithConstants avgt 5 > 2144.807 ? 162.685 ns/op > SCFB.makeConcatWithConstants:?gc.alloc.rate.norm avgt 5 > 3184.943 ? 4.495 B/op
Claes Redestad has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 17 additional commits since the last revision: - Merge branch 'master' into scf_chunked - We now don't need big Species classes for shorter concats, so on some tests the improvements meant more Species class generation. Adjusting HelloClasslist - Clarify that consts are always reduced to null, even if calling with constants. Also clarify that the number of constants is paramCount + 1 by refactoring to an array - Mandy review comment #1: Cleanup LF.basicType a bit more. - Cleanup too generic String.valueOf lookups - Address review comments from @ExE-Boss - Improve bootstrap microbenchmark to include more shapes, reduce runtime - Minor stylistic cleanup - Revert change to HelloClasslist (doesn't affect generation) - Reduce allocation adding in mixers by extracting constant arg lists and caching double arg mixers - ... and 7 more: https://git.openjdk.java.net/jdk/compare/98404245...afe61394 ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/8855/files - new: https://git.openjdk.java.net/jdk/pull/8855/files/aaa442d5..afe61394 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8855&range=07 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8855&range=06-07 Stats: 59296 lines in 765 files changed: 33676 ins; 19450 del; 6170 mod Patch: https://git.openjdk.java.net/jdk/pull/8855.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/8855/head:pull/8855 PR: https://git.openjdk.java.net/jdk/pull/8855
