The original was reverted for breaking webkit layout tests:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8-Blink%20Linux%2064/30270
It also caused the following clusterfuzz failures:
chromium:935832
This was a correctness bug due to not properly handling the case of arrays with prototypes other
than Array.prototype. Accesses that were TheHole were not being handled property, both in bounds
holes in holey arrays and out of bounds on either holey or packed arrays. Handling was incorrect
both in access-assembler and in Turbofan.
chromium:935932
This bug was that there was no handling for Has checks on the global object. Turbofan was emitting
code for a store (the 'else' condition on 'access_mode == AccessMode::kLoad'). It hit a DCHECK in
debug builds but in release could show up in different places. This is the bug that caused the
webkit layout test failure that led to the revert.
Both bugs are fixed by in CL, and tests are added for those cases.
Bug: v8:8733, chromium:935932, chromium:935832
Change-Id: Iba0dfcfce6e15d2c0815a7670ece67bc13ba1925
Reviewed-on: https://chromium-review.googlesource.com/c/1493132
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Matt Gardner <magardn@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#59958}
This reverts commit 32fc0acfef.
Reason for revert:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8-Blink%20Linux%2064/30270
layout test breakage:
https://test-results.appspot.com/data/layout_results/V8-Blink_Linux_64/30270/webkit_layout_tests%20%28with%20patch%29/layout-test-results/results.html
There is a dead node arriving in representation selection, which might indicate that the problem is not in this CL, but that this CL stirs up the node soup in such a way that dead code elimination gets confused.
Original change's description:
> Optimize `in` operator
>
> This change implements optimizations for the `in` operator for packed array
> elements and object properties. It adds a new feedback slot kind and an IC
> path similar to KeyedLoadIC for handling the lookups. TurboFan uses the
> feedback to optimize based on the maps and keys.
>
> For more details see:
> https://docs.google.com/document/d/1tIfzywY8AeNVcy_sen-5Xev21MeZwjcU8QhSdzHvXig
>
> This can provide 10x performance improvements of on loops of the form:
>
> for (let i = 0; i < ary.length; ++i) {
> if (i in ary) {
> ...
> }
> }
>
>
> Bug: v8:8733
> Change-Id: I766bf865a547a059e5bce5399bb6112e5d9a85c8
> Reviewed-on: https://chromium-review.googlesource.com/c/1432598
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Commit-Queue: Matt Gardner <magardn@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#59843}
TBR=ulan@chromium.org,rmcilroy@chromium.org,jkummerow@chromium.org,jarin@chromium.org,ishell@chromium.org,bmeurer@chromium.org,verwaest@chromium.org,magardn@microsoft.com
Change-Id: Ib2db974e5bed4c4a2b6b450f796bdc4b0b8fd562
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8733
Reviewed-on: https://chromium-review.googlesource.com/c/1488761
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59857}
This change implements optimizations for the `in` operator for packed array
elements and object properties. It adds a new feedback slot kind and an IC
path similar to KeyedLoadIC for handling the lookups. TurboFan uses the
feedback to optimize based on the maps and keys.
For more details see:
https://docs.google.com/document/d/1tIfzywY8AeNVcy_sen-5Xev21MeZwjcU8QhSdzHvXig
This can provide 10x performance improvements of on loops of the form:
for (let i = 0; i < ary.length; ++i) {
if (i in ary) {
...
}
}
Bug: v8:8733
Change-Id: I766bf865a547a059e5bce5399bb6112e5d9a85c8
Reviewed-on: https://chromium-review.googlesource.com/c/1432598
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Matt Gardner <magardn@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#59843}
