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  1. 20 Sep, 2016 1 commit
  3. 18 Apr, 2016 1 commit
    • jarin's avatar
      [turbofan] Effect linearization after representation inference. · b9e287c6
      jarin authored 
      This introduces a compiler pass that schedules the graph and re-wires effect chain according to the schedule. It also connects allocating representation changes to the effect chain, and removes the BeginRegion and EndRegion nodes - they should not be needed anymore because all effectful nodes should be already wired-in.

This is an intermediate CL - the next step is to move lowering of the Change*ToTaggedEffect nodes to StateEffectIntroduction so that we do not have to introduce the effectful versions of nodes.

Review URL: https://codereview.chromium.org/1849603002

Cr-Commit-Position: refs/heads/master@{#35565}
      b9e287c6
  5. 04 Apr, 2016 1 commit
    • titzer's avatar
      [turbofan] Handle dead diamonds in scheduling and add a test. · 45d75bca
      titzer authored 
      The background here is that graphs generated from WASM are not trimmed.
That means there can be some floating control diamonds that are not
reachable from end. An assertion in the scheduler for phis from floating
diamonds checks that the use edge in this situation is the control edge,
but in general, any edge could cause this.

Scheduling still works without this assertion. The longer term fix
is to either trim the graphs (more compile time overhead for WASM)
or improve the scheduler's handling of dead code in the graph. Currently
it does not schedule dead code but the potential use positions of
dead code are used in the computation of the common dominator of uses. We could
recognize dead nodes in PrepareUses() and check in GetBlockForUse()
as per TODO.

R=bradnelson@chromium.org, mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1846933002

Cr-Commit-Position: refs/heads/master@{#35245}
      45d75bca
  7. 11 Jan, 2016 1 commit
  9. 14 Oct, 2015 1 commit
    • jarin's avatar
      [turbofan] Introduce node regions for protection from scheduling. · 59c616cc
      jarin authored 
      This CL re-purposes ValueEffect and Finish as delimiters for regions
that are scheduled atomically (renamed to BeginRegion, FinishRegion).

The BeginRegion node takes and produces an effect. For the uses that do
not care about the placement in the effect chain, it is ok to feed
graph->start() as an effect input.

The FinishRegion takes a value and an effect and produces a value and
an effect. It is important that any value or effect produced inside the
region is not used outside the region. The FinishRegion node is the only
way to smuggle an effect and a value out.

At the moment, this does not support control flow inside the region. Control flow would be hard.

During scheduling we do some sanity check, but the checks are not exhaustive. Here is what we check:
- the effect chain between begin and finish is linear (no splitting,
  single effect input and output).
- any value produced is consumed by the FinishRegion node.
- no control flow outputs.

Review URL: https://codereview.chromium.org/1399423002

Cr-Commit-Position: refs/heads/master@{#31265}
      59c616cc
  11. 19 Jun, 2015 1 commit
  13. 06 May, 2015 1 commit
  15. 05 May, 2015 1 commit
    • bmeurer's avatar
      [turbofan] Fix tail call optimization. · d21de2a4
      bmeurer authored 
      Tail calls are matched on the graph, with a dedicated tail call
optimization that is actually testable. The instruction selection can
still fall back to a regular if the platform constraints don't allow to
emit a tail call (i.e. the return locations of caller and callee differ
or the callee takes non-register parameters, which is a restriction that
will be removed in the future).

Also explicitly limit tail call optimization to stubs for now and drop
the global flag.

BUG=v8:4076
LOG=n

Review URL: https://codereview.chromium.org/1114163005

Cr-Commit-Position: refs/heads/master@{#28219}
      d21de2a4
  17. 04 May, 2015 1 commit
  19. 30 Apr, 2015 1 commit
    • svenpanne's avatar
      Detect simple tail calls · 4b122b75
      svenpanne authored 
      This CL contains the first steps towards tail call optimization:

  * Structurally detect tail calls during instruction selection,
    looking for special return/call combinations.

  * Added new architecture-specific instructions for tail calls which
    jump instead of call and take care of frame adjustment.

  * Moved some code around.

Currently we restrict tail calls to callees which only use registers
for arguments/return value and to call sites which are explicitly
marked as being OK for tail calls. This excludes, among other things,
call sites in sloppy JS functions and our IC machinery (both need in
general to be able to access the caller's frame).

All this is behind a flag --turbo-tail-calls, which is currently off
by default, so it can easily be toggled.

Review URL: https://codereview.chromium.org/1108563002

Cr-Commit-Position: refs/heads/master@{#28150}
      4b122b75
  21. 20 Apr, 2015 1 commit
  23. 19 Mar, 2015 1 commit
  25. 17 Mar, 2015 1 commit
  27. 04 Mar, 2015 1 commit
  29. 25 Feb, 2015 3 commits
  31. 24 Feb, 2015 1 commit
  33. 23 Feb, 2015 1 commit
  35. 20 Feb, 2015 1 commit
  37. 18 Feb, 2015 1 commit
  39. 17 Feb, 2015 1 commit
    • bmeurer's avatar
      [turbofan] Optimize certain chains of Branch into a Switch. · acd9c46c
      bmeurer authored 
      This adds a new ControlFlowOptimizer that - for now - recognizes chains
of Branches generated by the SwitchBuilder for a subset of javascript
switches into Switch nodes. Those Switch nodes are then lowered to
either table or lookup switches.

Also rename Case to IfValue (and introduce IfDefault) for consistency.

BUG=v8:3872
LOG=n

Review URL: https://codereview.chromium.org/931623002

Cr-Commit-Position: refs/heads/master@{#26691}
      acd9c46c
  41. 12 Feb, 2015 1 commit
  43. 09 Feb, 2015 1 commit
  45. 03 Feb, 2015 2 commits
  47. 30 Jan, 2015 3 commits
  49. 29 Jan, 2015 2 commits
  51. 27 Jan, 2015 1 commit
    • bmeurer's avatar
      [turbofan] Ensure that NTLs are always properly connected to the end. · 59a02ebd
      bmeurer authored 
      Up until now we used a special Terminate node to artifically connect non
terminating loops to the End node, but this was kind of adhoc and didn't
work for the CFG. So without all kinds of weird hacks, the end block in
the CFG will not be connected to NTLs, which makes it impossible to
compute post dominance / control dependence in the current setting.

So instead of Terminate, we add a special Branch to NTLs, whose
condition is the special Always node, which corresponds to True, except
that it cannot be folded away. This way we don't need any special
machinery in the scheduler, since it's just a regular Branch.

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/875263004

Cr-Commit-Position: refs/heads/master@{#26294}
      59a02ebd
  53. 23 Jan, 2015 1 commit
  55. 22 Jan, 2015 1 commit
  57. 20 Jan, 2015 1 commit
  59. 16 Jan, 2015 1 commit
  61. 12 Jan, 2015 1 commit
  63. 07 Jan, 2015 1 commit
    • bmeurer's avatar
      [turbofan] Cleanup Graph and related classes. · e53845d4
      bmeurer authored 
      - Move NodeMarker to its own file, and introduce a non
  templatized base class.
- Cleanup the include hell.
- Sanitize the Node construction methods now that we
  got rid of that GenericNode/GenericGraph stuff.
- Protect against NodeId overflow in Graph.
- Various minor cleanups.

TEST=cctest,mjsunit,unittests

Review URL: https://codereview.chromium.org/838783002

Cr-Commit-Position: refs/heads/master@{#25977}
      e53845d4
  65. 17 Dec, 2014 1 commit
  67. 02 Dec, 2014 1 commit