This CL reverses the count logic for the tiering strategy of the
js-to-wasm wrappers. The initial approach was that calls to each
function were counted up, until a threshold was reached and the function
would tier up. With this CL, each function is assigned a budget of calls
that can be handled through the generic wrapper. Calls are counted down
until the budget is exhausted, which will trigger the tier-up
for the function.
This approach comes with two advantages. Firstly, determining whether
a function's budget is exhausted is as simple as checking the flags set
from the decrement of the budget. Secondly, the code generated by the
generic wrapper does not depend on the specific value of the initial
budget.
Bug: v8:10982
Change-Id: I5e186c6cf836a9c197b41d0f7ad075b07c87a4da
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2532300
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Vicky Kontoura <vkont@google.com>
Cr-Commit-Position: refs/heads/master@{#71153}
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