This gives us more precise type information, so we can avoid some type
guards to refine the type information back.
The motivation for this is to help escape analysis by not introducing
redundant type guards (which escape analysis cannot handle yet even
though it could and should do).
Motivating example:
In the example below, the out-of-object property array for properties
fld5 and fld6 gets type Any when it is created by "o.fld5 = 5" (for
object literals, we store 4 properties in-objeca, the rest goes out
of object).
When we run load elimination for the load the out-of-object property
array (to store 6 into o.fld6), load elimination inserts TypeGuard to
enforce the Type::Internal() type. This makes escape analysis bail out
on this object, and we do not eliminate the object creation.
function f() {
var o = {};
o.fld1 = 1;
o.fld2 = 2;
o.fld3 = 3;
o.fld4 = 4;
o.fld5 = 5;
o.fld6 = 6;
}
f();
f();
%OptimizeFunctionOnNextCall(f);
f();
Review-Url: https://codereview.chromium.org/2797993006
Cr-Commit-Position: refs/heads/master@{#44470}
Add a more efficient encoding for state values that have a large number of
optimized-out inputs.
Review-Url: https://codereview.chromium.org/2509623002
Cr-Commit-Position: refs/heads/master@{#42088}
Hook up TurboFan with the existing field type tracking machinery to
eliminate redundant map checks on the results of LoadField operators.
The store side is already implemented in TurboFan for quite some time,
this just adds the load part.
R=jarin@chromium.org
BUG=v8:5267
Review-Url: https://codereview.chromium.org/2604393002
Cr-Commit-Position: refs/heads/master@{#42015}
This adds a new ExternalPointer type, which is an Internal type that is
used for ExternalReferences and other pointer values, like the pointers
into the asm.js heap. It also adds a PointerConstant operator, which we
use to represents these raw constants (we can probably remove that
particular operator again once WebAssembly ships with the validator).
R=mvstanton@chromium.org
BUG=v8:5267,v8:5270
Review-Url: https://codereview.chromium.org/2494753003
Cr-Commit-Position: refs/heads/master@{#40923}
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 makes sure the {EscapeAnalysisReducer} inserts proper {TypeGuard}
nodes if the replacement node is not a subtype of the original node.
This happens predominantly for code that has been made unreachable by
type checks.
R=jarin@chromium.org
TEST=mjsunit/regress/regress-crbug-640497
BUG=chromium:640497
Review URL: https://codereview.chromium.org/2363573003 .
Cr-Commit-Position: refs/heads/master@{#39656}
This makes sure cycles in the object states graph are detected early by
escape analysis instead of late in the scheduler. This is mainly done
for improved debuggability.
R=bmeurer@chromium.org
BUG=chromium:613923
Review-Url: https://codereview.chromium.org/2354263002
Cr-Commit-Position: refs/heads/master@{#39614}
This is some initial cleanup to keep /src clean. The
AccountingAllocator is actually exclusively used by zones and this
common subfolder makes that more clear.
BUG=v8:5409
Review-Url: https://codereview.chromium.org/2344143003
Cr-Commit-Position: refs/heads/master@{#39558}
So far TurboFan wasn't adding the deoptimization reasons for eager/soft
deoptimization exits that can be used by either the DevTools profiler or
the --trace-deopt flag. This adds basic support for deopt reasons on
Deoptimize, DeoptimizeIf and DeoptimizeUnless nodes and threads through
the reasons to the code generation.
Also moves the DeoptReason to it's own file (to resolve include cycles)
and drops unused reasons.
R=jarin@chromium.org
Review-Url: https://codereview.chromium.org/2161543002
Cr-Commit-Position: refs/heads/master@{#37823}
These are used to check for Smi or HeapObject, and we use them
appropriately in JSNativeContextSpecialization, so we don't need
to introduce dependencies on concrete control flow and/or concrete
frame states.
They will be optimized by a proper check elimination reducer,
which will be added in a separate CL.
R=jarin@chromium.org
BUG=v8:4470
Review-Url: https://codereview.chromium.org/2082523002
Cr-Commit-Position: refs/heads/master@{#37096}
This CL removes the Config templatization from the types. It is not
necessary anymore, after the HeapTypes have been removed.
The CL also changes the type hierarchy - the specific type kinds are
not inner classes of the Type class and they do not inherit from Type.
This is partly because it seems impossible to make this work without
templates. Instead, a new TypeBase class is introduced and all the
structural (i.e., non-bitset) types inherit from it.
The bitset type still requires the bit-munging hack and some nasty
reinterpret-casts to pretend bitsets are of type Type*. Additionally,
there is now the same hack for TypeBase - all pointers to the sub-types
of TypeBase are reinterpret-casted to Type*. This is to keep the type
constructors in inline method definitions (although it is unclear how
much that actually buys us).
In future, we would like to move to a model where we encapsulate Type*
into a class (or possibly use Type where we used to use Type*). This
would loosen the coupling between bitset size and pointer size, and
eventually we would be able to have more bits.
TBR=bradnelson@chromium.org
Review URL: https://codereview.chromium.org/1655833002
Cr-Commit-Position: refs/heads/master@{#33656}
* Add caching to handling of dangling loads
* Add two unittests for load elimination on escaped objects
BUG=v8:4586
LOG=n
Review URL: https://codereview.chromium.org/1619103004
Cr-Commit-Position: refs/heads/master@{#33498}
* Treat Select nodes as escaping
* Correctly void virtual field information
after a store to a non-const index
* Add a shortcut if all allocates escape
* Add a shortcut if no allocates are discovered
* Only reduce FrameState/StateValues nodes if they
have virtual allocates as input (transitively)
* Fix bug in FrameState/StateValues duplication
* Add check to verifier: First 3 inputs of FrameState
must be StateValues
R=mstarzinger@chromium.org
BUG=v8:4586
LOG=n
Review URL: https://codereview.chromium.org/1583213003
Cr-Commit-Position: refs/heads/master@{#33406}
This bug improves performance of escape analysis.
* A allocation discovery phase (EscapeAnalysis::AssignAliases)
ensures compact representation of virtual state
* Node revisiting in EscapeStatusAnalysis has been improved
* Escape analysis no longer requires a trimmed graph
BUG=v8:4586
LOG=n
Review URL: https://codereview.chromium.org/1559123003
Cr-Commit-Position: refs/heads/master@{#33267}
Deopt support is added on two levels. On the IR level,
a new ObjectState node is added, which represenents an
object to be materialized. ObjectState nodes appear as
inputs of FrameState and StateValues nodes. On the
instruction select/code-generation level, the
FrameStateDescriptor class handles the nesting
introduced by ObjectState, and ensures that deopt code
with CAPTURED_OBJECT/DUPLICATED_OBJECT entries are
generated similarly to what crankshaft's escape
analysis does.
Two unittests test correctness of the IR level implementation.
Correctness for instruction selection / code generation
is tested by mjsunit tests.
R=jarin@chromium.org,mstarzinger@chromium.org
BUG=v8:4586
LOG=n
Review URL: https://codereview.chromium.org/1485183002
Cr-Commit-Position: refs/heads/master@{#33115}
Move replacements out of virtual object. Replacements are
global to the graph and are not dependent on the virtual
state (after they are discovered).
R=mstarzinger@chromium.org
BUG=v8:4586
LOG=n
Review URL: https://codereview.chromium.org/1527533002
Cr-Commit-Position: refs/heads/master@{#32838}
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}
This is the first part of escape analysis for turbofan.
At the moment, there is no deopt support, and support
for loops is partial (only binary Phis are handled).
The CL includes 4 unittests.
There are also 8 new mjsunit tests, some of which are
skiped as they require features not yet implemented.
BUG=v8:4586
LOG=n
Review URL: https://codereview.chromium.org/1457683003
Cr-Commit-Position: refs/heads/master@{#32498}
