This CL switches over our OSR system to be based on the feedback
vector osr caches.
- OSRing to Sparkplug is fully separated from OSR urgency. If
SP code exists, we simply jump to it, no need to maintain an
installation request.
- Each JumpLoop checks its dedicated FeedbackVector cache slot.
If a valid target code object exists, we enter it *without*
calling into runtime to fetch the code object.
- Finally, OSR urgency still remains as the heuristic for
requesting Turbofan OSR compile jobs. Note it no longer has a
double purpose of being a generic untargeted installation
request.
With the new system in place, we can remove now-unnecessary
hacks:
- Early OSR tierup is replaced by the standard OSR system. Any
present OSR code is automatically entered.
- The synchronous OSR compilation fallback is removed. With
precise installation (= per-JumpLoop-bytecode) we no longer
have the problem of 'getting unlucky' with JumpLoop/cache entry
mismatches. Execution has moved on while compiling? Simply spawn
a new concurrent compile job.
- Remove the synchronous (non-OSR) Turbofan compile request now
that we always enter available OSR code as early as possible.
- Tiering into Sparkplug no longer messes with OSR state.
Bug: v8:12161
Change-Id: I0a85e53d363504b7dac174dbaf69c03c35e66700
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3596167
Commit-Queue: Jakob Linke <jgruber@chromium.org>
Auto-Submit: Jakob Linke <jgruber@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80147}
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