This is a reland of 4b15b984ad
Updates since original: fix an arithmetic overflow bug, remove an invalid
DCHECK, add a unit test that would trigger that DCHECK.
Original change's description:
> [regexp] Better quick checks on loop entry nodes
>
> Like the predecessor change https://crrev.com/c/v8/v8/+/1702125 , this
> change is inspired by attempting to exit earlier from generated RegExp
> code, when no further matches are possible because any match would be
> too long. The motivating example this time is the following expression,
> which tests whether a string of Unicode playing cards has five of the
> same suit in a row:
>
> /([🂡-🂮]{5})|([🂱-🂾]{5})|([🃁-🃎]{5})|([🃑-🃞]{5})/u
>
> A human reading this expression can readily see that any match requires
> at least 10 characters (5 surrogate pairs), but the LoopChoiceNode for
> each repeated option reports its minimum distance to the end of a match
> as zero. This is correct, because the LoopChoiceNode's behavior depends
> on additional state (the loop counter). However, the preceding node, a
> SET_REGISTER action that initializes the loop counter, could confidently
> state that it consumes at least 10 characters. Furthermore, when we try
> to emit a quick check for that action, we could follow only paths from
> the LoopChoiceNode that are possible based on the minimum iteration
> count. This change implements both of those "could"s.
>
> I expect this improvement to apply pretty broadly to expressions that
> use minimum repetition counts and that don't meet the criteria for
> unrolling. In this particular case, I get about 12% improvement on the
> overall UniPoker test, due to reducing the execution time of this
> expression by 85% and the execution time of another similar expression
> that checks for n-of-a-kind by 20%.
>
> Bug: v8:9305
>
> Change-Id: I319e381743967bdf83324be75bae943fbb5dd496
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1704941
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62963}
Bug: v8:9305
Change-Id: I992070d383009013881bf778242254c27134b650
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1726674
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#63009}
bea0ffd0dd