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}
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}
MachineType is now a class with two enum fields:
- MachineRepresentation
- MachineSemantic
Both enums are usable on their own, and this change switches some places from using MachineType to use just MachineRepresentation. Most notably:
- register allocator now uses just the representation.
- Phi and Select nodes only refer to representations.
Review URL: https://codereview.chromium.org/1513543003
Cr-Commit-Position: refs/heads/master@{#32738}
The test had an effect phi with one effect input connected to a loop with two control inputs. Also, the Terminate node was used by the effect phi.
Review URL: https://codereview.chromium.org/1398763002
Cr-Commit-Position: refs/heads/master@{#31193}
Verifies consistency of node inputs and uses:
- node inputs should agree with the input count computed from the node's operator.
- effect inputs should have effect outputs (or be a sentinel).
- control inputs should have control outputs (or be a sentinel).
- frame state inputs should be frame states (or be a sentinel).
- if the node has control uses, it should produce control.
- if the node has effect uses, it should produce effect.
- if the node has frame state uses, it must be a frame state.
I also removed some tests, either because they did not seem to be useful (scheduler) or they tested dead functionality (diamond effect phi).
Review URL: https://codereview.chromium.org/1368913002
Cr-Commit-Position: refs/heads/master@{#30927}
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 introduces a conservative prediction for each exception handler
whether it will locally catch an exception or re-throw it to outside
the code bondaries. It will allow for a more intuitive prediction of
whether an exception is considered "caught" or "uncaught".
R=bmeurer@chromium.org,yangguo@chromium.org
BUG=chromium:492522
LOG=N
Review URL: https://codereview.chromium.org/1158563008
Cr-Commit-Position: refs/heads/master@{#28681}
This simplifies the handling of the End node. Based on this CL we will
finally fix terminating every loop from the beginning (via Terminate
nodes) and fix inlining of Throw, Deoptimize and Terminate.
R=mstarzinger@chromium.org
Review URL: https://codereview.chromium.org/1157023002
Cr-Commit-Position: refs/heads/master@{#28620}
Use these check points to optimize comparisons where we already know
that one side cannot be a String (or turn into a string via
ToPrimitive).
Also remove bunch of useless DoNotCrash tests for the scheduler that are
painful to maintain and add almost no value.
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1140583004
Cr-Commit-Position: refs/heads/master@{#28383}
This revives the Terminate operator and removes the weird Always
operator. As a first step we let the ControlReducer connect non
terminating loops via Terminate. The next step will be to change the
graph builder to insert Terminate nodes into every loop.
Review URL: https://codereview.chromium.org/1123213002
Cr-Commit-Position: refs/heads/master@{#28259}
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}
Implements the strong mode proposal's restrictions on
implicit conversions for binary arithmetic operations, not
including the + special case. Adds some infrastructure
for future implementation of the restrictions for other
operators.
BUG=v8:3956
LOG=N
Review URL: https://codereview.chromium.org/1092353002
Cr-Commit-Position: refs/heads/master@{#28045}
Now all nodes that care about deoptimization always take frame state
inputs no matter whether deoptimization is enabled for a particular
function. In case that deoptimization is off, the AstGraphBuilder just
inserts the empty frame state. This greatly simplifies the logic in
various places and makes testing easier as well, and is probably the
first step towards enabling --turbo-deoptimization by default.
There seems to be no noticable performance impact on asm.js programs.
Also fix the graph replay in order to regenerate the scheduler unittests.
Review URL: https://codereview.chromium.org/1106613003
Cr-Commit-Position: refs/heads/master@{#28026}
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}
Adds Switch and Case operators to TurboFan and handles them
appropriately in instruction selection and code generation.
BUG=v8:3872
LOG=n
Review URL: https://codereview.chromium.org/892513003
Cr-Commit-Position: refs/heads/master@{#26515}
If a (pure) node has two or more uses, but there exists a path from the
common dominator of these uses to end, which does not contain a use,
then we split the node such that no unnecessary computation takes place.
Note however, that this only applies if the node cannot be hoisted out
of a loop.
BUG=v8:3864
LOG=n
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/899433005
Cr-Commit-Position: refs/heads/master@{#26404}
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}
