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  1. 19 Mar, 2019 1 commit
    • Benedikt Meurer's avatar
      [turbofan] Significantly improve ConsString creation performance. · d6a60a0e
      Benedikt Meurer authored 
      This change significantly improves the performance of string
concatenation in optimized code for the case where the resulting string
is represented as a ConsString. On the relevant test cases we go from

  serializeNaive: 10762 ms.
  serializeClever: 7813 ms.
  serializeConcat: 10271 ms.

to

  serializeNaive: 10278 ms.
  serializeClever: 5533 ms.
  serializeConcat: 10310 ms.

which represents a 30% improvement on the "clever" benchmark, which
tests specifically the ConsString creation performance.

This was accomplished via a couple of different steps, which are briefly
outlined here:

  1. The empty_string gets its own map, so that we can easily recognize
     and handle it appropriately in the TurboFan type system. This
     allows us to express (and assert) that the inputs to NewConsString
     are non-empty strings, making sure that TurboFan no longer creates
     "crippled ConsStrings" with empty left or right hand sides.
  2. Further split the existing String types in TurboFan to be able to
     distinguish between OneByte and TwoByte strings on the type system
     level. This allows us to avoid having to dynamically lookup the
     resulting ConsString map in case of ConsString creation (i.e. when
     we know that both input strings are OneByte strings or at least
     one of the input strings is TwoByte).
  3. We also introduced more finegrained feedback for the Add bytecode
     in the interpreter, having it collect feedback about ConsStrings,
     specifically ConsOneByteString and ConsTwoByteString. This feedback
     can be used by TurboFan to only inline the relevant code for what
     was seen so far. This allows us to remove the Octane/Splay specific
     magic in JSTypedLowering to detect ConsString creation, and instead
     purely rely on the feedback of what was seen so far (also making it
     possible to change the semantics of NewConsString to be a low-level
     operator, which is only introduced in SimplifiedLowering by looking
     at the input types of StringConcat).
  4. On top of the before mentioned type and interpreter changes we added
     new operators CheckNonEmptyString, CheckNonEmptyOneByteString, and
     CheckNonEmptyTwoByteString, which perform the appropriate (dynamic)
     checks.

There are several more improvements that are possible based on this, but
since the change was already quite big, we decided not to put everything
into the first change, but do some follow up tweaks to the type system,
and builtin optimizations later.

Tbr: mstarzinger@chromium.org
Bug: v8:8834, v8:8931, v8:8939, v8:8951
Change-Id: Ia24e17c6048bf2b04df966d3cd441f0edda05c93
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Doc: https://bit.ly/fast-string-concatenation-in-javascript
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1499497
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
Reviewed-by: 's avatarJaroslav Sevcik <jarin@chromium.org>
Reviewed-by: 's avatarMythri Alle <mythria@chromium.org>
Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60318}
      d6a60a0e
  3. 07 Mar, 2019 1 commit
  5. 15 Feb, 2019 1 commit
  7. 12 Feb, 2019 1 commit
  9. 18 Dec, 2018 1 commit
  11. 11 Dec, 2018 1 commit
  13. 04 Dec, 2018 1 commit
  15. 27 Nov, 2018 1 commit
  17. 26 Nov, 2018 1 commit
  19. 11 Oct, 2018 1 commit
  21. 03 Oct, 2018 1 commit
  23. 02 Oct, 2018 1 commit
  25. 17 Sep, 2018 1 commit
  27. 14 Sep, 2018 1 commit
  29. 31 Jul, 2018 1 commit
  31. 26 Jul, 2018 1 commit
  33. 23 Jul, 2018 2 commits
  35. 18 Jul, 2018 1 commit
  37. 16 Jul, 2018 1 commit
  39. 13 Jul, 2018 1 commit
    • Michael Lippautz's avatar
      Revert "Reland "[heap] Added External Strings to external memory accounting."" · 71dddd14
      Michael Lippautz authored 
      This reverts commit 7bff339e.

Reason for revert: Breaks autoroll, see bug.

Bug: v8:7944

Original change's description:
> Reland "[heap] Added External Strings to external memory accounting."
> 
> This is a reland of 5863c0b6
> 
> Original change's description:
> > [heap] Added External Strings to external memory accounting.
> > 
> > Bug: chromium:845409
> > Change-Id: I3fe2b294f6e038d77787cf0870d244ba7cc20550
> > Reviewed-on: https://chromium-review.googlesource.com/1118164
> > Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#54110}
> 
> Bug: chromium:845409
> Change-Id: Ied341ec6268000343d2a577b22f2a483460b01f5
> Reviewed-on: https://chromium-review.googlesource.com/1121736
> Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54410}

TBR=ulan@chromium.org,hpayer@chromium.org,mlippautz@chromium.org,petermarshall@chromium.org,rfbpb@google.com

Change-Id: Ie55586e84f44a2d83c7f97110d60abb86f0730c5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:845409
Reviewed-on: https://chromium-review.googlesource.com/1136312Reviewed-by: 's avatarMichael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54428}
      71dddd14
  41. 12 Jul, 2018 2 commits
  43. 10 Jul, 2018 1 commit
  45. 04 Jul, 2018 2 commits
  47. 21 Jun, 2018 1 commit
  49. 09 May, 2018 1 commit
    • Dan Elphick's avatar
      Reland "[heap] Mark RO_SPACE as read-only after deserialization" · 60064133
      Dan Elphick authored 
      This is a reland of 40f1aaf3

Put back padding clearing into the SerializeObject method but only when
the String is not in RO_SPACE. For RO_SPACE strings, if required
iterate over the space before serialization clearing the strings.

Original change's description:
> [heap] Mark RO_SPACE as read-only after deserialization
>
> Adds MarkAsReadOnly and MarkAsReadWrite to ReadOnlySpace. The latter
> is only usable with ReadOnlySpace::WritableScope to avoid the space
> being left writable). MarkAsReadOnly updates the high water mark and
> makes several previously mutating methods into no-ops.
>
> Moves some writes to immutable objects out of the bootstrapper to
> setup-heap-internal so they don't write to a read-only page.
>
> Also avoid writing hashes to strings that already have the value set as
> that invariably means writing to the "0" and "1" constant strings in
> RO_SPACE.
>
> Before serialization, it makes RO_SPACE writable again so that any
> padding can be cleared before writing it.
>
> Bug: v8:7464
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
> Change-Id: I22edc20dba7dde8943991a8fcaf87244af4490a3
> Reviewed-on: https://chromium-review.googlesource.com/1014128
> Commit-Queue: Dan Elphick <delphick@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52943}

Bug: v8:7464
Change-Id: Ia8386c4ff5f5df3207f584caf7a9b1ff1e405f25
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1042145Reviewed-by: 's avatarHannes Payer <hpayer@chromium.org>
Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53087}
      60064133
  51. 03 May, 2018 2 commits
    • Michael Achenbach's avatar
      Revert "[heap] Mark RO_SPACE as read-only after deserialization" · d14bca61
      Michael Achenbach authored 
      This reverts commit 40f1aaf3.

Reason for revert:
https://luci-milo.appspot.com/buildbot/client.v8/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/21000

Original change's description:
> [heap] Mark RO_SPACE as read-only after deserialization
> 
> Adds MarkAsReadOnly and MarkAsReadWrite to ReadOnlySpace. The latter
> is only usable with ReadOnlySpace::WritableScope to avoid the space
> being left writable). MarkAsReadOnly updates the high water mark and
> makes several previously mutating methods into no-ops.
> 
> Moves some writes to immutable objects out of the bootstrapper to
> setup-heap-internal so they don't write to a read-only page.
> 
> Also avoid writing hashes to strings that already have the value set as
> that invariably means writing to the "0" and "1" constant strings in
> RO_SPACE.
> 
> Before serialization, it makes RO_SPACE writable again so that any
> padding can be cleared before writing it.
> 
> Bug: v8:7464
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
> Change-Id: I22edc20dba7dde8943991a8fcaf87244af4490a3
> Reviewed-on: https://chromium-review.googlesource.com/1014128
> Commit-Queue: Dan Elphick <delphick@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52943}

TBR=yangguo@chromium.org,hpayer@chromium.org,mlippautz@chromium.org,delphick@chromium.org

Change-Id: Id4770c0fdb21cd9eea2f62a019f44a6bdea8f0a7
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7464
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1041948Reviewed-by: 's avatarMichael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52944}
      d14bca61
    • Dan Elphick's avatar
      [heap] Mark RO_SPACE as read-only after deserialization · 40f1aaf3
      Dan Elphick authored 
      Adds MarkAsReadOnly and MarkAsReadWrite to ReadOnlySpace. The latter
is only usable with ReadOnlySpace::WritableScope to avoid the space
being left writable). MarkAsReadOnly updates the high water mark and
makes several previously mutating methods into no-ops.

Moves some writes to immutable objects out of the bootstrapper to
setup-heap-internal so they don't write to a read-only page.

Also avoid writing hashes to strings that already have the value set as
that invariably means writing to the "0" and "1" constant strings in
RO_SPACE.

Before serialization, it makes RO_SPACE writable again so that any
padding can be cleared before writing it.

Bug: v8:7464
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I22edc20dba7dde8943991a8fcaf87244af4490a3
Reviewed-on: https://chromium-review.googlesource.com/1014128
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: 's avatarHannes Payer <hpayer@chromium.org>
Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52943}
      40f1aaf3
  53. 02 May, 2018 1 commit
    • Leszek Swirski's avatar
      Revert "[parser] Slice the source string where possible" · 18bc2856
      Leszek Swirski authored 
      This reverts commit 2df5e7a7.

Reason for revert: Mystery crashes https://bugs.chromium.org/p/chromium/issues/detail?id=838805

Original change's description:
> [parser] Slice the source string where possible
> 
> When internalizing string literals (for quoted strings or property names),
> try to create a sliced string of the source string rather than allocating
> a copy of the bytes.
> 
> This will not work for string literals that contain escapes (e.g. unicode
> escapes), and currently does not support two-byte strings.
> 
> Bug: chromium:818642
> Change-Id: I686e5ad36baecd1a84ce5e124118431249b6c980
> Reviewed-on: https://chromium-review.googlesource.com/1010282
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52898}

TBR=marja@chromium.org,yangguo@chromium.org,jarin@chromium.org,mlippautz@chromium.org,leszeks@chromium.org,verwaest@chromium.org

Change-Id: I598b6668c43a3e843e2dd8e60852b2b2f3461954
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:818642
Reviewed-on: https://chromium-review.googlesource.com/1039885
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52919}
      18bc2856
  55. 01 May, 2018 1 commit
  57. 18 Apr, 2018 1 commit
  59. 09 Apr, 2018 2 commits
  61. 06 Apr, 2018 2 commits
    • Michael Achenbach's avatar
      Revert "[cleanup] Refactor the Factory" · 503e07c3
      Michael Achenbach authored 
      This reverts commit f9a2e24b.

Reason for revert: gc stress failures not all fixed by follow up.

Original change's description:
> [cleanup] Refactor the Factory
> 
> There is no good reason to have the meat of most objects' initialization
> logic in heap.cc, all wrapped by the CALL_HEAP_FUNCTION macro. Instead,
> this CL changes the protocol between Heap and Factory to be AllocateRaw,
> and all object initialization work after (possibly retried) successful
> raw allocation happens in the Factory.
> 
> This saves about 20KB of binary size on x64.
> 
> Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
> Change-Id: Icbfdc4266d7be8b48d2fe085f03411743dc6a0ca
> Reviewed-on: https://chromium-review.googlesource.com/959533
> Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52416}

TBR=jkummerow@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org,hpayer@chromium.org

Change-Id: Idbbc53478742f3e9525eee83342afc6aedae122f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/999414Reviewed-by: 's avatarMichael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52420}
      503e07c3
    • Jakob Kummerow's avatar
      [cleanup] Refactor the Factory · f9a2e24b
      Jakob Kummerow authored 
      There is no good reason to have the meat of most objects' initialization
logic in heap.cc, all wrapped by the CALL_HEAP_FUNCTION macro. Instead,
this CL changes the protocol between Heap and Factory to be AllocateRaw,
and all object initialization work after (possibly retried) successful
raw allocation happens in the Factory.

This saves about 20KB of binary size on x64.

Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Icbfdc4266d7be8b48d2fe085f03411743dc6a0ca
Reviewed-on: https://chromium-review.googlesource.com/959533
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: 's avatarHannes Payer <hpayer@chromium.org>
Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52416}
      f9a2e24b
  63. 20 Feb, 2018 1 commit
  65. 13 Feb, 2018 1 commit
    • Sigurd Schneider's avatar
      Reland "[cleanup] Harden the SubString CSA/Runtime implementations." · bb282636
      Sigurd Schneider authored 
      This is a reland of 6d5b54df82e27a82811a836dcdbbfe26829f0e6d
Original change's description:
> [cleanup] Harden the SubString CSA/Runtime implementations.
>
> Remove the self-healing for invalid parameters in the
> CodeStubAssembler::SubString helper and the %SubString runtime function,
> which is used as a fallback for the CodeStubAssembler implementation.
> All call sites must do appropriate parameter validation anyways now that
> the self-hosted JavaScript builtins using these helpers are gone, and we
> have proper contracts with the uses.
>
> Also remove the context parameter from the CodeStubAssembler::SubString
> method, which is unnecessary, since this can no longer throw an
> exception.
>
> Bug: v8:5269, v8:6936, v8:7109, v8:7137
> Change-Id: I19d93bad5f41faa0561c4561a48f78fcba99a549
> Reviewed-on: https://chromium-review.googlesource.com/795720
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49702}

Bug: v8:5269, v8:6936, v8:7109, v8:7137
Change-Id: I5e84998a2dd3990d7981505b401ffc770e0b7ac5
Reviewed-on: https://chromium-review.googlesource.com/913130Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51265}
      bb282636
  67. 06 Feb, 2018 1 commit