This adds appropriate LoopExit nodes for the JSCallReducer lowerings of
the following higher order Array builtins:
- Array.prototype.every()
- Array.prototype.find()
- Array.prototype.findIndex()
- Array.prototype.some()
Loop peeling allows TurboFan to make loop invariant operations in the
callback passed to the higher order builtin fully redundant, and thus
completely eliminate the loop invariant code from the subsequent loop
iterations. This can have a huge performance impact, depending on what
kind of code runs inside of the callback. For example, on the micro-
benchmarks outlined in http://crbug.com/v8/8273 we go from
forLoop: 364 ms.
every: 443 ms.
some: 432 ms.
find: 522 ms.
findIndex: 437 ms.
to
forLoop: 369 ms.
every: 354 ms.
some: 348 ms.
find: 419 ms.
findIndex: 360 ms.
which is 20% improvement, and essentially brings the Array builtins (the
appropriate ones Array#some() and Array#every() in this case) on par
with the hand-written `for`-loop.
Bug: v8:1956, v8:8273
Change-Id: I9d32736e5402807b4ac79cd5ad15ceacd1945681
Reviewed-on: https://chromium-review.googlesource.com/c/1305935
Reviewed-by: Daniel Clifford <danno@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57110}
