Commit Graph

14 Commits

Author SHA1 Message Date
Igor Sheludko
15c9ff0758 [runtime] Remove --modify-field-representation-inplace flag
which was enabled a long ago and is not supposed to be disabled.

In addition this CL adds Representation::MightCauseMapDeprecation()
predicate and ensures it's consistent with the existing
MostGenericInPlaceChange() and CanBeInPlaceChangedTo().

Bug: v8:11104, v8:8865
Change-Id: Ia8046b76822c9b20fe3ce85de6b98570334aad21
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2527088
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71151}
2020-11-12 13:44:15 +00:00
Ross McIlroy
5b794a389b [Test] Add PrepareForOptimization to some mjsunit tests.
Bug: v8:8801, v8:8394
Change-Id: I6bb46ecafe1bd94adbf0409f13c9b2e558da0823
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1594558
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Auto-Submit: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61200}
2019-05-03 13:32:32 +00:00
Jaroslav Sevcik
cb451fe59d Remove FLAG_track_constant_fields
This enables constant field tracking unconditionally.

TBR=jgruber@chromium.org

Bug: v8:8361
Change-Id: I02f35827d860c3e0f18a3d55cb156c088d48bc94
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1585730
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61055}
2019-04-27 10:47:19 +00:00
Benedikt Meurer
f11ba854e5 [map] Support in-place field representation changes.
This adds a new flag --modify-field-representation-inplace (enabled by
default), which lets the runtime perform field representation changes
for Smi to Tagged or for HeapObject to Tagged in-place instead of
creating new maps and marking the previous map tree as deprecated.

That means we create (a lot) fewer Maps and DescriptorArrays in the
beginning and also need to self-heal fewer objects later (migrating
off the deprecated maps). In TurboFan we just take the "field owner
dependency" whenever we use the field representation, which is very
similar to what we already do for the field types. That means if we
change the representation of a field that we used in optimized code,
we will simply deoptimize that code and have TurboFan potentially
later optimize it again with the new field representation.

On the Speedometer2/ElmJS-TodoMVC test, this reduces the total execution
time from around 415ms to around 352ms, which corresponds to a **15%**
improvement. The overall Speedometer2 score improves from around 74.1
to around 78.3 (on local runs with content_shell), corresponding to a
**5.6%** improvement here. 🎉

On the CNN desktop browsing story, it seems that we reduce map space
utilization/fragmentation by about 4-5%. But since we allocate a lot
less (fewer Maps and DescriptorArrays) we also significantly change
the GC timing, which heavily influences the results here. So take this
with a grain of salt. 🤷

Note: For Double fields, this doesn't change anything, meaning they
still create new maps and deprecate the previous map trees.

Bug: v8:8749, v8:8865, v8:9114
Change-Id: Ibd70efcb59be982863905663dbfaa89aa5b31e14
Cq-Include-Trybots: luci.chromium.try:linux-rel,win7-rel
Doc: http://bit.ly/v8-in-place-field-representation-changes
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1565891
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60822}
2019-04-12 14:37:07 +00:00
Michael Hablich
48efe388d8 Revert "[map] Support in-place field representation changes."
This reverts commit 1416d5a565.

Reason for revert: blocks roll https://chromium-review.googlesource.com/c/chromium/src/+/1564550

Original change's description:
> [map] Support in-place field representation changes.
> 
> This adds a new flag --modify-field-representation-inplace (enabled by
> default), which lets the runtime perform field representation changes
> for Smi to Tagged or for HeapObject to Tagged in-place instead of
> creating new maps and marking the previous map tree as deprecated.
> 
> That means we create (a lot) fewer Maps and DescriptorArrays in the
> beginning and also need to self-heal fewer objects later (migrating
> off the deprecated maps). In TurboFan we just take the "field owner
> dependency" whenever we use the field representation, which is very
> similar to what we already do for the field types. That means if we
> change the representation of a field that we used in optimized code,
> we will simply deoptimize that code and have TurboFan potentially
> later optimize it again with the new field representation.
> 
> On the Speedometer2/ElmJS-TodoMVC test, this reduces the total execution
> time from around 415ms to around 352ms, which corresponds to a **15%**
> improvement. The overall Speedometer2 score improves from around 74.1
> to around 78.3 (on local runs with content_shell), corresponding to a
> **5.6%** improvement here. 🎉
> 
> On the CNN desktop browsing story, it seems that we reduce map space
> utilization/fragmentation by about 4-5%. But since we allocate a lot
> less (fewer Maps and DescriptorArrays) we also significantly change
> the GC timing, which heavily influences the results here. So take this
> with a grain of salt. 🤷‍♂️
> 
> Note: For Double fields, this doesn't change anything, meaning they
> still create new maps and deprecate the previous map trees.
> 
> Bug: v8:8749, v8:8865, v8:9114
> Change-Id: I694a53f87ae5caeb868fd98a21809b66d4297d35
> Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
> Doc: http://bit.ly/v8-in-place-field-representation-changes
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1561132
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#60764}

TBR=jarin@chromium.org,neis@chromium.org,ishell@chromium.org,bmeurer@chromium.org,verwaest@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:8749, v8:8865, v8:9114
Change-Id: I666975d08d51bbe7ab4faec9428b9a1f88e9b322
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1564208
Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Michael Hablich <hablich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60807}
2019-04-12 10:37:04 +00:00
Benedikt Meurer
1416d5a565 [map] Support in-place field representation changes.
This adds a new flag --modify-field-representation-inplace (enabled by
default), which lets the runtime perform field representation changes
for Smi to Tagged or for HeapObject to Tagged in-place instead of
creating new maps and marking the previous map tree as deprecated.

That means we create (a lot) fewer Maps and DescriptorArrays in the
beginning and also need to self-heal fewer objects later (migrating
off the deprecated maps). In TurboFan we just take the "field owner
dependency" whenever we use the field representation, which is very
similar to what we already do for the field types. That means if we
change the representation of a field that we used in optimized code,
we will simply deoptimize that code and have TurboFan potentially
later optimize it again with the new field representation.

On the Speedometer2/ElmJS-TodoMVC test, this reduces the total execution
time from around 415ms to around 352ms, which corresponds to a **15%**
improvement. The overall Speedometer2 score improves from around 74.1
to around 78.3 (on local runs with content_shell), corresponding to a
**5.6%** improvement here. 🎉

On the CNN desktop browsing story, it seems that we reduce map space
utilization/fragmentation by about 4-5%. But since we allocate a lot
less (fewer Maps and DescriptorArrays) we also significantly change
the GC timing, which heavily influences the results here. So take this
with a grain of salt. 🤷‍♂️

Note: For Double fields, this doesn't change anything, meaning they
still create new maps and deprecate the previous map trees.

Bug: v8:8749, v8:8865, v8:9114
Change-Id: I694a53f87ae5caeb868fd98a21809b66d4297d35
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Doc: http://bit.ly/v8-in-place-field-representation-changes
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1561132
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60764}
2019-04-11 08:59:33 +00:00
ishell
a4f4c74050 [runtime][ic] Constant field tracking support.
This CL includes runtime and IC parts of the tracking. It is controlled by
compile-time flag FLAG_constant_field_tracking and currently disabled.

Transition from kConst to kMutable still involves map deprecation.

BUG=v8:5495

Review-Url: https://codereview.chromium.org/2598543003
Cr-Commit-Position: refs/heads/master@{#43081}
2017-02-10 08:05:25 +00:00
verwaest@chromium.org
6f358946ac Disable map-check relying on cache behavior sensitive to GC-timing
R=mstarzinger@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23892005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16544 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-09-05 08:36:10 +00:00
verwaest@chromium.org
16199c63d8 Initialized representations of computed values to None.
R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14721009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14982 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-06-06 14:21:35 +00:00
verwaest@chromium.org
8db3014974 Keep representations while overwriting transitions.
BUG=chromium:241477
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15718002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14745 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-22 10:46:33 +00:00
verwaest@chromium.org
73d084fad3 Fix bugs in rewriting combined with attributes and accessors
R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14843023

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14713 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-17 03:16:20 +00:00
verwaest@chromium.org
52008429b7 Use mutable heapnumbers to store doubles in fields.
R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14850006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14597 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-08 15:02:08 +00:00
verwaest@chromium.org
46d39cabd6 Fix polymorphic to monomorphic load to take representation into account.
Review URL: https://chromiumcodereview.appspot.com/14966005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14565 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-07 10:32:23 +00:00
verwaest@chromium.org
99e17bb12a Track storage types of instance variables.
Review URL: https://chromiumcodereview.appspot.com/14146005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14464 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-26 15:30:41 +00:00