commit db1cbfa124770ec6b96924fa3bafcc5357f1ab91
author Igor Sheludko <ishell@chromium.org> Thu May 08 00:05:16 2025
committer V8 LUCI CQ <v8-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu May 08 08:56:24 2025
tree 2ed55bad436e68d25826b453182fd1d349841c3b
parent e34c9753072bbdab5ef7c10edb8b7eed5ef9281e

[runtime] Split NumberToString cache to caches for Smis and doubles

This is a preliminary step before making it possible to store raw
doubles in the latter cache. Currently the keys in the latter cache
are HeapNumber objects.

This split also makes it possible to
 - avoid eviction of Smi entries by double entries (the former seem to
   be more important for performance),
 - avoid additional checks for distinguishing Smi keys from double
   keys,
 - configure cache size growing strategy independently,
 - configure tweak cache clearing logic based on "keys".

As a side effect this CL increases the overall number of entries in
combined number-to-string cache by 1.5.

Drive-by:
 - add collection of number to string cache usage statistics
   behind --trace-number-string-cache flag (requires gn argument
   `v8_enable_snapshot_native_code_counters = true` to enable counters
   machinery in builtins),
 - add flags for configuring full number to string cache sizes.

This CL changes heap layout and may regress some benchmarks, however
the follow up CLs should recover potential regressions.

Bug: 409808503
Change-Id: Ie33c6847c2608af5e359830ac4bbcc7017791bd1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6512976
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/main@{#100146}