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  1. 16 Sep, 2020 1 commit
  3. 11 Sep, 2020 1 commit
  5. 18 Aug, 2020 1 commit
  7. 13 Aug, 2020 1 commit
  9. 10 Aug, 2020 1 commit
  11. 31 Jul, 2020 3 commits
  13. 30 Jul, 2020 3 commits
  15. 28 Jul, 2020 2 commits
    • Ross McIlroy's avatar
      [TurboProp] Add reference map population to fast reg alloc. · e9a37bf8
      Ross McIlroy authored 
      Adds support for populating reference maps to the fast
register allocator. In order to calculate whether a stack slot
is live at a given instruction, we use the dominator tree to
build a bitmap of blocks which are dominated by each block.
A variable's spill operand is classed as alive for any blocks that are
dominated by the block it was defined in, until the instruction index
of the spill operand's last use. As such, it may be classified as live
down a branch where the spill operand is never used, however it is safe
since the spill slot won't be re-allocated until after it's last-use
instruction index in any case.

BUG=v8:9684

Change-Id: I772374599ef916f57d82d468f66429e32c712ddf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2298008
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69108}
      e9a37bf8
    • Ross McIlroy's avatar
      [TurboProp] Add support for spill slot allocation to fast reg alloc · 5b0c6cde
      Ross McIlroy authored 
      Adds support for tracking the instruction range of spilled operands,
and then allocating spill slots to these ranges. It also adds some
unittests covering spill slot allocation.

Spill slots are allocated in a linear fashion, running through the
instruction stream in a linear order, ensuring that no spill operand
is allocated to a same spill slot that is already assigned to during
this whole start / end range. This isn’t optimal, since it doesn’t
take into account holes in these ranges (e.g, blocks between start
and end that aren’t dominated by the start), but in practice rarely
leads to more than one extra spill slot being allocated compared to
the current allocator.

BUG=v8:9684

Change-Id: Iedee7bcf552080e5b4b6a2f4e96b78b6c1396cab
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2297470Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69107}
      5b0c6cde
  17. 24 Jul, 2020 2 commits
  19. 22 Jul, 2020 1 commit
    • Seth Brenith's avatar
      Profile-guided optimization of builtins · 922983df
      Seth Brenith authored 
      Design doc:
https://docs.google.com/document/d/1szInbXZfaErWW70d30hJsOLL0Es-l5_g8d2rXm1ZBqI/edit?usp=sharing

V8 can already collect data about how many times each basic block in the
builtins is run. This change enables using that data for profile-guided
optimization. New comments in BUILD.gn describe how to use this feature.

A few implementation details worth mentioning, which aren't covered in
the design doc:

- BasicBlockProfilerData currently contains an array of RPO numbers.
  However, this array is always just [0, 1, 2, 3, ...], so this change
  removes that array. A new DCHECK in BasicBlockInstrumentor::Instrument
  ensures that the removal is valid.

- RPO numbers, while useful for printing data that matches with the
  stringified schedule, are not useful for matching profiling data with
  blocks that haven't been scheduled yet. This change adds a new array
  of block IDs in BasicBlockProfilerData, so that block counters can be
  used for PGO.

- Basic block counters need to be written to a file so that they can be
  provided to a subsequent run of mksnapshot, but the design doc doesn't
  specify the transfer format or what file is used. In this change, I
  propose using the existing v8.log file for that purpose. Block count
  records look like this:

  block,TestLessThanHandler,37,29405

  This line indicates that block ID 37 in TestLessThanHandler was run
  29405 times. If multiple lines refer to the same block, the reader
  adds them all together. I like this format because it's easy to use:
  - V8 already has robust logic for creating the log file, naming it to
    avoid conflicts in multi-process situations, etc.
  - Line order doesn't matter, and interleaved writes from various
    logging sources are fine, given that V8 writes each line atomically.
  - Combining multiple sources of profiling data is as simple as
    concatenating their v8.log files together.

- It is a good idea to avoid making any changes based on profiling data
  if the function being compiled doesn't match the one that was
  profiled, since it is common to use profiling data downloaded from a
  central lab which is updated only periodically. To check whether a
  function matches, I propose using a hash of the Graph state right
  before scheduling. This might be stricter than necessary, as some
  changes to the function might be small enough that the profile data is
  still relevant, but I'd rather err on the side of not making incorrect
  changes. This hash is also written to the v8.log file, in a line that
  looks like this:

  builtin_hash,LdaZeroHandler,3387822046

Bug: v8:10470
Change-Id: I429e5ce5efa94e01e7489deb3996012cf860cf13
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2220765
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69008}
      922983df
  21. 14 Jul, 2020 2 commits
  23. 10 Jul, 2020 2 commits
  25. 06 Jul, 2020 3 commits
  27. 30 Jun, 2020 1 commit
    • Jakob Gruber's avatar
      [nci] Add feedback input to Call nodes · 2b236e33
      Jakob Gruber authored 
      This is likely the major change of the series, as Call nodes are the
focus of call reducer (and to a lesser extent other phases like
inlining).

This CL essentially adds the new input to Call nodes, and updates the
rest of the pipeline. As a (fairly large) drive-by, I also introduce
the JSCallNode wrapper class and apply it in call reducer.

This change, although large, will hopefully make future refactorings
*much* easier, since it is now clear where certain assumptions about
Call node layout are made.

Bug: v8:8888
Change-Id: Ia15fe0ba459b6034863a5815a4e4662cee41fc83
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2264353
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68616}
      2b236e33
  29. 23 Jun, 2020 2 commits
  31. 15 Jun, 2020 1 commit
    • Jakob Gruber's avatar
      [nci] Add native_context_independent flags · f30b53bd
      Jakob Gruber authored 
      ... to OptimizedCompilationInfo, BytecodeGraphBuilder, and
JSHeapBroker.

Also add first uses of these flags in pipeline.cc by skipping certain
phases when nci is enabled. With this change, tests in the NCI variant
will start to fail since generic lowering is not fully implemented.
These implementations will follow incrementally in the next days.

Bug: v8:8888
Change-Id: I3f570fb92f09059d1f1f4015f88ffe80ccf746ad
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2239572
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68339}
      f30b53bd
  33. 10 Jun, 2020 2 commits
  35. 08 Jun, 2020 2 commits
  37. 03 Jun, 2020 1 commit
  39. 02 Jun, 2020 2 commits
  41. 25 May, 2020 1 commit
    • Ross McIlroy's avatar
      [TurboProp] Don't try to rewire unreachable blocks to end. · f34771f7
      Ross McIlroy authored 
      We can't consistently rewire the successor blocks of an unreachable node to
disconnect them from the graph when we are trying to maintain the schedule.
Instead simply leave the code there. As a future optimization we could add a
proper scheduled dead code elimination phase which can deal with this.

As a side-effect, one of the tests sees a int64 DeadValue, so add support for that
in the instruction selector.

BUG=chromium:1083272,chromium:1083763,chromium:1084953,v8:9684

Change-Id: I69a6feaeef4eae62110392e27ea848b28bccf787
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2209061
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Auto-Submit: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67953}
      f34771f7
  43. 22 May, 2020 1 commit
    • Seth Brenith's avatar
      [torque] Generate better code when using `&` operator on bitfields · 98438d86
      Seth Brenith authored 
      Sometimes CSA code carefully constructs a mask to check several
bitfields at once. Thus far, such a check has been very awkward to write
in Torque. This change adds a way to do so, using the
non-short-circuiting binary `&` operator. So now you can write an
expression that depends on several bitfields from a bitfield struct,
like `x.a == 5 & x.b & !x.c & x.d == 2` (assuming b is a one-bit value),
and it will be reduced to a single mask and equality check. To
demonstrate a usage of this new reduction, this change ports the trivial
macro IsSimpleObjectMap to Torque. I manually verified that the
generated code for the builtin SetDataProperties, which uses that macro,
is unchanged.

Bug: v8:7793
Change-Id: I4a23e0005d738a6699ea0f2a63f9fd67b01e7026
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2183276
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67948}
      98438d86
  45. 13 May, 2020 1 commit
  47. 06 May, 2020 1 commit
    • Ross McIlroy's avatar
      [TurboProp] Fully remove successors from schedule on unreachable. · 66e1c84d
      Ross McIlroy authored 
      Fully remove the successor blocks when effect-control-linearization
reaches an unreachable node and is maintaining the schedule. Previously
we just updated the current_block_'s successor and removed any
unreachable predecessors from end, however if the current_block_ is not
an original block in the schedule, but a new one added due to control
flow from effect control linearization lowering, the removed successor
blocks could still be re-connected to the end block when they were
lowered. Instead, entirely remove these unreachable blocks from the
predecessor / successor chains, and have the effect-control-linearizer
avoid lowering these blocks entirely.

BUG=chromium:1076569,v8:9684

Change-Id: I4b4216019d55aef5363d88255726b85df8e7ada5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2179842Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67595}
      66e1c84d
  49. 01 May, 2020 1 commit
  51. 29 Apr, 2020 1 commit
    • Tobias Tebbi's avatar
      Reland "Reland "[turbofan][csa] optimize Smi untagging better"" · 9e9cd5df
      Tobias Tebbi authored 
      This is a reland of 43b885a8
This fixes another signed overflow in the unit test.

Original change's description:
> Reland "[turbofan][csa] optimize Smi untagging better"
>
> This is a reland of ff22ae80
>
> Original change's description:
> > [turbofan][csa] optimize Smi untagging better
> >
> > - Introduce new operator variants for signed right-shifts with the
> >   additional information that they always shift out zeros.
> > - Use these new operators for Smi untagging.
> > - Merge left-shifts with a preceding Smi-untagging shift.
> > - Optimize comparisons of Smi-untagging shifts to operate on the
> >   unshifted word.
> > - Optimize 64bit comparisons of values expanded from 32bit to use
> >   a 32bit comparison instead.
> > - Change CodeStubAssembler::UntagSmi to first sign-extend and then
> >   right-shift to enable better address computations for Smi indices.
> >
> > Bug: v8:9962
> > Change-Id: If91300f365e8f01457aebf0bd43bdf88b305c460
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2135734
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Georg Neis <neis@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#67378}
>
> Bug: v8:9962
> Change-Id: Ieab0755806c95fb50022eb17596fb0c95f36004c
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2170001
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67430}

Bug: v8:9962
TBR: neis@chromium.org
Change-Id: I79883db546bf37873b3727b8023ef688507091d9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2169103
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67464}
      9e9cd5df