This adds a simple counter to Turbofan that's incremented throughout the compilation, hopefully
frequently enough so we can use it to detect divergence and performance bugs.
In addition, we assert that this counter never gets too high. That's the equivalent of a simple
timeout, just more deterministic. The limitations on Turbofan input size should guarantee that
we never exceed this limit. Since we probably do exceed it rarely, this check is only a DCHECK and
intended to detect performance and divergence issues, but not supposed to be performed in release
builds.
In addition, this CL adds UMA stats to observe the real world distribution of the tick measurement.
Bug: v8:9444
Change-Id: I182dac6ecac64715e3f5885ff5c7c17549351cd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1695475
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62754}
Currently only A test operators had output, but since ABReducer and BCReducer
perform in-place replacement of A nodes into B nodes, and then sometimes into
C nodes, we need B and C nodes to have as many outputs. Otherwise, we run into
a situation where a node {x} has a use {y}, but its operators has 0 outputs,
which is inconsistent.
Bug:
Change-Id: I0f73b83d2115dfeda3c9cbc97b9a2fc168f4c31b
Reviewed-on: https://chromium-review.googlesource.com/603716
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Alexandre Talon <alexandret@google.com>
Cr-Commit-Position: refs/heads/master@{#47202}
Each reducer now has a virtual reducer_name function, returning its name
(the name of the class containing this reducer). This gets displayed when
using the --trace_turbo_reduction flag. Also when using this flags more
messages are displayed.
Actually when a node is replaced in-place (which is called an update
of the node), other reducers can still update it right after the
in-place replacement. When a node is really replaced (not in-place),
then we stop trying to apply reducers to it before we propagate the
reduction through the relevant nodes.
Before a message got printed only for the last reduction it went
through. So in case a node was reduced in-place several times
in a row, only the last update was printed, or none at all if after
being reduced in-place it got reduced by being replaced by another
node: only the non-in-place replacement was showed.
Now each time an in-place reduction is applied to a node, a message
gets printed.
Bug:
Change-Id: Id0f816fecd44c01d0253966c6decc4861be0c2fa
Reviewed-on: https://chromium-review.googlesource.com/563365
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Alexandre Talon <alexandret@google.com>
Cr-Commit-Position: refs/heads/master@{#46552}
This is preparation for using TF to create builtins that handle variable number of
arguments and have to remove these arguments dynamically from the stack upon
return.
The gist of the changes:
- Added a second argument to the Return node which specifies the number of stack
slots to pop upon return in addition to those specified by the Linkage of the
compiled function.
- Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
handles all tail-call cases except where the return value type differs, this fallback
was not really useful and in fact caused unexpected behavior with variable
sized argument popping, since it wasn't possible to materialize a Return node
with the right pop count from the TailCall without additional context.
- Modified existing Return generation to pass a constant zero as the additional
pop argument since the variable pop functionality
LOG=N
Review-Url: https://codereview.chromium.org/2446543002
Cr-Commit-Position: refs/heads/master@{#40699}
Reason for revert:
Seems to break arm64 sim debug and blocks roll:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20debug/builds/3294
Original issue's description:
> [turbofan] Support variable size argument removal in TF-generated functions
>
> This is preparation for using TF to create builtins that handle variable number of
> arguments and have to remove these arguments dynamically from the stack upon
> return.
>
> The gist of the changes:
> - Added a second argument to the Return node which specifies the number of stack
> slots to pop upon return in addition to those specified by the Linkage of the
> compiled function.
> - Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
> handles all tail-call cases except where the return value type differs, this fallback
> was not really useful and in fact caused unexpected behavior with variable
> sized argument popping, since it wasn't possible to materialize a Return node
> with the right pop count from the TailCall without additional context.
> - Modified existing Return generation to pass a constant zero as the additional
> pop argument since the variable pop functionality
>
> LOG=N
TBR=bmeurer@chromium.org,mstarzinger@chromium.org,epertoso@chromium.org,danno@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2473643002
Cr-Commit-Position: refs/heads/master@{#40691}
This is preparation for using TF to create builtins that handle variable number of
arguments and have to remove these arguments dynamically from the stack upon
return.
The gist of the changes:
- Added a second argument to the Return node which specifies the number of stack
slots to pop upon return in addition to those specified by the Linkage of the
compiled function.
- Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
handles all tail-call cases except where the return value type differs, this fallback
was not really useful and in fact caused unexpected behavior with variable
sized argument popping, since it wasn't possible to materialize a Return node
with the right pop count from the TailCall without additional context.
- Modified existing Return generation to pass a constant zero as the additional
pop argument since the variable pop functionality
LOG=N
Review-Url: https://codereview.chromium.org/2446543002
Cr-Commit-Position: refs/heads/master@{#40678}
This completely removes translation of exception handler predictions
from the graph IR. We now rely on the runtime using deoptimization
infomation via {FrameSummary} for predictions in optimized code.
R=bmeurer@chromium.org
Review-Url: https://codereview.chromium.org/2207533002
Cr-Commit-Position: refs/heads/master@{#38250}
This introduces the NodeProperties::ChangeOp helper which guards node
operator changes so that additional checking can be done without any
additional dependencies being pulled into the Node class. For now only
the input count is checked, but additional checking might follow.
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1366753003
Cr-Commit-Position: refs/heads/master@{#30916}
Reason for revert:
Looks like this breaks Tests262.
Original issue's description:
> [turbofan] Run DeadCodeElimination together with the advanced reducers.
>
> This will immediately remove dead code from the graph once any of
> the advanced reducers inserts it. Also changes the GraphReducer to
> use the canonical Dead node for ReplaceWithValue.
>
> R=jarin@chromium.org
>
> Committed: https://crrev.com/88a40c5fb381924b1c0b2403dc582bceb2abe5da
> Cr-Commit-Position: refs/heads/master@{#29217}
TBR=jarin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1200983004
Cr-Commit-Position: refs/heads/master@{#29220}
This will immediately remove dead code from the graph once any of
the advanced reducers inserts it. Also changes the GraphReducer to
use the canonical Dead node for ReplaceWithValue.
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1206533002
Cr-Commit-Position: refs/heads/master@{#29217}
The three different concerns that the ControlReducer used to deal with
are now properly separated into
a.) DeadCodeElimination, which is a regular AdvancedReducer, that
propagates Dead via control edges,
b.) CommonOperatorReducer, which does strength reduction on common
operators (i.e. Branch, Phi, and friends), and
c.) GraphTrimming, which removes dead->live edges from the graph.
This will make it possible to run the DeadCodeElimination together with
other passes that actually introduce Dead nodes, i.e. typed lowering;
and it opens the door for general inlining without two stage fix point
iteration.
To make the DeadCodeElimination easier and more uniform, we basically
reverted the introduction of DeadValue and DeadEffect, and changed the
Dead operator to produce control, value and effect. Note however that
this is not a requirement, but merely a way to make dead propagation
easier and more uniform. We could always go back and decide to have
different Dead operators if some other change requires that.
Note that there are several additional opportunities for cleanup now,
i.e. OSR deconstruction could be a regular reducer now, and we don't
need to use TheHole as dead value marker in the GraphReducer. And we can
actually run the dead code elimination together with the other passes
instead of using separate passes over the graph. We will do this in
follow up CLs.
R=jarin@chromium.org, mstarzinger@chromium.org
Review URL: https://codereview.chromium.org/1193833002
Cr-Commit-Position: refs/heads/master@{#29146}
Up until now we used int32_t for NodeId, but that was not ideal because
negative values are invalid for NodeId and we use it as an array index
for example in the NodeMarker class, where C++ compilers on x64 have to
generate code that does proper sign extension for the indices, which is
completely unnecessary.
R=svenpanne@chromium.org
Review URL: https://codereview.chromium.org/1178403004
Cr-Commit-Position: refs/heads/master@{#28997}
This is needed in order to allow expansion of a throwing node into a
set of nodes that produce different effects for the successful and the
exceptional continuation.
R=bmeurer@chromium.org
Review URL: https://codereview.chromium.org/1179543002
Cr-Commit-Position: refs/heads/master@{#28918}
This allows any AdvancedReducer to remove exception projections from
graphs. This is the common case when JS-operators are being replaced
with pure values. The old NodeProperties::ReplaceWithValue is being
deprecated in favor of AdvancedReducer::ReplaceWithValue.
R=titzer@chromium.org
TEST=unittests/AdvancedReducerTest
Review URL: https://codereview.chromium.org/1168693002
Cr-Commit-Position: refs/heads/master@{#28810}
An AdvancedReducer is basically a regular Reducer with an editor
that can perform graph editing operations beyond changing or
replacing the node that is currently being reduced. The GraphReducer
is the default implementation of the AdvancedReducer::Editor interface.
The ControlReducerImpl is now just an AdvancedReducer, which
temporarily requires a Finish method in the reducer to implement
the dead node trimming until we move that to the GraphReducer
(which in turn requires that all loops are connected to End).
Review URL: https://codereview.chromium.org/1122423003
Cr-Commit-Position: refs/heads/master@{#28251}
- 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}
Don't use the generic algorithm, but instead start going into the
direction of ControlReducer, using a stack plus a revisit queue to
not miss any more possibilities for reductions anymore.
TEST=cctest,unittests
R=dcarney@chromium.org
Committed: f047507370
Committed: 6e148989a4
Review URL: https://codereview.chromium.org/726513002
Cr-Commit-Position: refs/heads/master@{#25377}
Don't use the generic algorithm, but instead start going into the
direction of ControlReducer, using a stack plus a revisit queue to
not miss any more possibilities for reductions anymore.
TEST=cctest,unittests
R=dcarney@chromium.org
Committed: f047507370
Review URL: https://codereview.chromium.org/726513002
Cr-Commit-Position: refs/heads/master@{#25345}
Don't use the generic algorithm, but instead start going into the
direction of ControlReducer, using a stack plus a revisit queue to
not miss any more possibilities for reductions anymore.
TEST=cctest,unittests
R=dcarney@chromium.org
Review URL: https://codereview.chromium.org/726513002
Cr-Commit-Position: refs/heads/master@{#25326}
