Commit Graph

72 Commits

Author SHA1 Message Date
Ryan Macnak 1e24fe7d69 [vm, compiler] Specialize unoptimized monomorphic and megamorphic calls.
dart-bytecode, arm64:            +4.742% geomean
dart-bytecode-jit-unopt, arm64: +12.73% geomean
dart2js-compile, x64:            +3.635% geomean

In the polymorphic and unlinked cases, call to a stub the does a linear scan against an ICData.

In the monomorphic case, call to a prologue of the expected target function that checks the expected receiver class. There is additional indirection in the JIT version compared to the AOT version to also tick a usage counter so the inliner can make good decisions.

In the megamorphic case, call to a stub that does a hash table lookup against a MegamorphicCache.

Megamorphic call sites face a loss of precision in usage counts. The call site count is not recorded and the usage counter of the target function is used as an approximation.

Monomorphic and megamorphic calls sites are reset to the polymorphic/unlinked state on hot reload.

Monomorphic and megamorphic calls sites do not check the stepping state, so they are reset to the polymorphic/unlinked state when stepping begins and disabled.

Back-edges now increment the usage counter in addition to checking it. This ensures function with loops containing monomorphic calls will eventually cross the optimization threshold.

Fixed backwards use of kMonomorphicEntryOffset and kPolymorphicEntryOffset.

Fixed C stack overflow when bouncing between the KBC interpreter and a simulator.

Bug: https://github.com/dart-lang/sdk/issues/26780
Bug: https://github.com/dart-lang/sdk/issues/36409
Bug: https://github.com/dart-lang/sdk/issues/36731
Change-Id: I78a49cccd962703a459288e71ce246ed845df474
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/102820
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2019-06-12 21:56:53 +00:00
Teagan Strickland a17b52c2c1 Revert "[vm, compiler] Unoptimized megamorphic calls."
This reverts commit fde6a5917e.

Reason for revert: This commit looks to be causing new test failures on dart2js. While there are some odd results on some builders that look like infra failures, some builders (for example, dart2js-minified-strong-linux-x64-d8) show the new failing tests clearly.

Original change's description:
> [vm, compiler] Unoptimized megamorphic calls.
> 
> When an instance call in unoptimized code creates more than FLAG_max_polymorphic_checks cases, switch the call to use a MegamorphicCache instead of ICData. The prevents unbounded collection of type feedback, and gives improvements on microbenchmarks in the 3-8% range for unoptimized code.
> 
> It also leads to a loss of target frequency information for the optimizer, leading to different ordering for range checks in polymorphic inlining. This leads to changes on megamorphic microbenchmarks from -31% to +60%, weighted toward the negative end.
> 
> In practice the frequency information seems unimportant, as dart2js has 4.01% geomean improvement.
> 
> This is a step toward direct monomorphic calls in unoptimized code, which will also make use of the patching and type feedback extraction added here.
> 
> Bug: https://github.com/dart-lang/sdk/issues/26780
> Bug: https://github.com/dart-lang/sdk/issues/36409
> Bug: https://github.com/dart-lang/sdk/issues/36731
> Change-Id: I29f53f23b6794c5f5f0db8b8184788cee16fd9c5
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/99270
> Reviewed-by: Alexander Markov <alexmarkov@google.com>

TBR=rmacnak@google.com,alexmarkov@google.com,ajcbik@google.com

Change-Id: Icad46b93cdf8541a00563f49da6b4ac0a4df1ba1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: https://github.com/dart-lang/sdk/issues/26780, https://github.com/dart-lang/sdk/issues/36409, https://github.com/dart-lang/sdk/issues/36731
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103440
Reviewed-by: Teagan Strickland <sstrickl@google.com>
Commit-Queue: Teagan Strickland <sstrickl@google.com>
2019-05-22 13:20:49 +00:00
Ryan Macnak fde6a5917e [vm, compiler] Unoptimized megamorphic calls.
When an instance call in unoptimized code creates more than FLAG_max_polymorphic_checks cases, switch the call to use a MegamorphicCache instead of ICData. The prevents unbounded collection of type feedback, and gives improvements on microbenchmarks in the 3-8% range for unoptimized code.

It also leads to a loss of target frequency information for the optimizer, leading to different ordering for range checks in polymorphic inlining. This leads to changes on megamorphic microbenchmarks from -31% to +60%, weighted toward the negative end.

In practice the frequency information seems unimportant, as dart2js has 4.01% geomean improvement.

This is a step toward direct monomorphic calls in unoptimized code, which will also make use of the patching and type feedback extraction added here.

Bug: https://github.com/dart-lang/sdk/issues/26780
Bug: https://github.com/dart-lang/sdk/issues/36409
Bug: https://github.com/dart-lang/sdk/issues/36731
Change-Id: I29f53f23b6794c5f5f0db8b8184788cee16fd9c5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/99270
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2019-05-21 19:44:27 +00:00
Vyacheslav Egorov f496e538f4 [vm] Decouple assemblers from runtime.
This is the next step towards preventing compiler from directly peeking
into runtime and instead interact with runtime through a well defined
surface. The goal of the refactoring to locate all places where compiler
accesses some runtime information and partion those accesses into two
categories:

- creating objects in the host runtime (e.g. allocating strings, numbers, etc)
during compilation;
- accessing properties of the target runtime (e.g. offsets of fields) to
embed those into the generated code;

This change introduces dart::compiler and dart::compiler::target namespaces.

All code in the compiler will gradually be moved into dart::compiler namespace.
One of the motivations for this change is to be able to prevent access to
globally defined host constants like kWordSize by shadowing them in the
dart::compiler namespace.

The nested namespace dart::compiler::target hosts all information about
target runtime that compiler could access, e.g. compiler::target::kWordSize
defines word size of the target which will eventually be made different
from the host kWordSize (defined by dart::kWordSize).

The API for compiler to runtime interaction is placed into compiler_api.h.

Note that we still permit runtime to access compiler internals directly -
this is not going to be decoupled as part of this work.

Issue https://github.com/dart-lang/sdk/issues/31709

Change-Id: If4396d295879391becfa6c38d4802bbff81f5b20
Reviewed-on: https://dart-review.googlesource.com/c/90242
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2019-01-25 16:45:13 +00:00
Martin Kustermann 28f8c96abe [VM] Bare instructions - Part 5: Get rid of CODE_REG indirection in SwitchableCalls
If the --use-bare-instructions flag is enabled we will:

  * Make call sites load the target directly from the pool (instead of
    the code object) - this saves one instruction (and an indirect load)

  * Ensure the object pool will have direct entry addresses by:

     - Letting the clustered snapshot reader change any StubCode::UnlinkedCall()
       in the object pool by it's monomorphic entry
     - Change the code patcher to patch SwitchableCalls by writing the
       monomorphic entry into the pool (instead of the code object)

Issue https://github.com/dart-lang/sdk/issues/33274

Change-Id: I4e41fc8e4461bde477cc559a6a4fccaaf3a350b5
Reviewed-on: https://dart-review.googlesource.com/c/86160
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2018-12-14 16:11:53 +00:00
Samir Jindel 921e62f1bf [vm] Introduce multiple entrypoints to AOT.
Cq-Include-Trybots: luci.dart.try:vm-kernel-win-release-x64-try, vm-kernel-optcounter-threshold-linux-release-x64-try, vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-release-simarm-try, vm-kernel-precomp-linux-release-simarm64-try, vm-kernel-precomp-linux-release-x64-try, vm-kernel-precomp-win-release-x64-try
Change-Id: I8643033febf9bdc57c8298dca5f43346fb8bf6d1
Reviewed-on: https://dart-review.googlesource.com/c/80304
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2018-12-07 13:19:24 +00:00
Ryan Macnak 7f55e52888 [vm, x64] Use short forms for object pool loads.
We now patch object pool entries instead of pool load indices.

dart2js release
AOT X64 Instructions(CodeSize): 10171808 -> 9567168 (-5.94%)
JIT X64 Instructions(CodeSize): 14298624 -> 13163968 (-7.94%)

Bug: https://github.com/dart-lang/sdk/issues/29077
Change-Id: I84938a5717b79d65e941141539d7f82e02c89858
Reviewed-on: https://dart-review.googlesource.com/c/78185
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Aart Bik <ajcbik@google.com>
2018-10-09 17:30:25 +00:00
Samir Jindel dea7de23bd [vm] Use multiple entrypoints to remove unnecessary checks on calls against "this".
Test Plan:

Behavioral correctness should be ensured by existing tests. Tests in vm/dart/entrypoints
ensure that the unchecked entrypoint is used in cases where the optimization should trigger.

Bug: https://github.com/dart-lang/sdk/issues/31798

Change-Id: I5b880b2dfa6343b4bb0a96ad23562facff73e41f
Cq-Include-Trybots: luci.dart.try:vm-kernel-win-release-x64-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/69741
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2018-08-20 16:56:22 +00:00
Martin Kustermann 3b414a277c Reland "[VM] Introduction of type testing stubs - Part 1-4"
Relands 165c583d57

    [VM] Introduction of type testing stubs - Part 1

    This CL:

      * Adds a field to [RawAbstractType] which will always hold a pointer
        to the entrypoint of a type testing stub

      * Makes this new field be initialized to a default stub whenever a
        instances are created (e.g. via Type::New(), snapshot reader, ...)

      * Makes the clustered snapshotter write a reference to the
        corresponding [RawInstructions] object when writing the field and do
        the reverse when reading it.

      * Makes us call the type testing stub for performing assert-assignable
        checks.

    To reduce unnecessary loads on callsites, we store the entrypoint of the
    type testing stubs directly in the type objects.  This means that the
    caller of type testing stubs can simply branch there without populating
    a code object first.  This also means that the type testing stubs
    themselves have no access to a pool and we therefore also don't hold on
    to the [Code] object, only the [Instruction] object is necessary.

    The type testing stubs do not setup a frame themselves and also have no
    safepoint.  In the case when the type testing stubs could not determine
    a positive answer they will tail-call a general-purpose stub.

    The general-purpose stub sets up a stub frame, tries to consult a
    [SubtypeTestCache] and bails out to runtime if this was unsuccessful.

    This CL is just the the first, for ease of reviewing.  The actual
    type-specialized type testing stubs will be generated in later CLs.

    Reviewed-on: https://dart-review.googlesource.com/44787

Relands f226c22424

    [VM] Introduction of type testing stubs - Part 2

    This CL starts building type testing stubs specialzed for [Type] objects
    we test against.

    More specifically, it adds support for:

      * Handling obvious fast cases on the call sites (while still having a
        call to stub for negative case)

      * Handling type tests against type parameters, by loading the value
        of the type parameter on the call sites and invoking it's type testing stub.

      * Specialzed type testing stubs for instantiated types where we can
        do [CidRange]-based subtype-checks.

        ==> e.g. String/List<dynamic>

      * Specialzed type testing stubs for instantiated types where we can
        do [CidRange]-based subclass-checks for the class and
        [CidRange]-based subtype-checks for the type arguments.

        ==> e.g. Widget<State>, where we know [Widget] is only extended and not
                 implemented.

      * Specialzed type testing stubs for certain non-instantiated types where we
        can do [CidRange]-based subclass-checks for the class and
        [CidRange]-based subtype-checks for the instantiated type arguments and
        cid based comparisons for type parameters.  (Note that this fast-case migth
        result in some false-negatives!)

        ==> e.g. _HashMapEntry<K, V>, where we know [_HashMapEntry] is only
                 extended and not implemented.

       This optimizes cases where the caller uses `new HashMap<A, B>()` and only
       uses `A` and `B` as key/values (and not subclasses of it).  The false-negative
       can occur when subtypes of A or B are used.  In such cases we fall back to the
       [SubtypeTestCache]-based imlementation.

    Reviewed-on: https://dart-review.googlesource.com/44788

Relands 25f98bcc75

    [VM] Introduction of type testing stubs - Part 3

    The changes include:

      * Make AssertAssignableInstr no longer have a call-summary, which
        helps methods with several parameter checks by not having to
        re-load/re-initialize type arguments registers

      * Lazily create SubtypeTestCaches: We already go to runtime to warm up
        the caches, so we now also create the caches on the first runtime
        call and patch the pool entries.

      * No longer load the destination name into a register: We only need
        the name when we throw an exception, so it is not on the hot path.
        Instead we let the runtime look at the call site, decoding a pool
        index from the instructions stream.  The destination name will be
        available in the pool, at a consecutive index to the subtype cache.

      * Remove the fall-through to N=1 case for probing subtypeing tests,
        since those will always be handled by the optimized stubs.

      * Do not generate optimized stubs for FutureOr<T> (so far it just
        falled-through to TTS).  We can make optimzed version of that later,
        but it requires special subtyping rules.

      * Local code quality improvement in the type-testing-stubs: Avoid
        extra jump at last case of cid-class-range checks.

    There are still a number of optimization opportunities we can do in
    future changes.

    Reviewed-on: https://dart-review.googlesource.com/46984

Relands 2c52480ec8

    [VM] Introduction of type testing stubs - Part 4

    In order to avoid generating type testing stubs for too many types in
    the system - and thereby potentially cause an increase in code size -
    this change introduces a smarter way to decide for which types we should
    generate optimized type testing stubs.

    The precompiler creates a [TypeUsageInfo] which we use to collect
    information.  More specifically:

       a) We collect the destination types for all type checks we emit
          (we do this inside AssertAssignableInstr::EmitNativeCode).

          -> These are types we might want to generate optimized type testing
             stubs for.

       b) We collect type argument vectors used in instance creations (we do
          this inside AllocateObjectInstr::EmitNativeCode) and keep a set of
          of used type argument vectors for each class.

    After the precompiler has finished compiling normal code we scan the set
    of destination types collected in a) for uninstantiated types (or more
    specifically, type parameter types).

    We then propagate the type argument vectors used on object allocation sites,
    which were collected in b), in order to find out what kind of types are flowing
    into those type parameters.

    This allows us to extend the set of types which we test against, by
    adding the types that flow into type parameters.

    We use this final augmented set of destination types as a "filter" when
    making the decision whether to generate an optimized type testing stub
    for a given type.

    Reviewed-on: https://dart-review.googlesource.com/48640

Issue https://github.com/dart-lang/sdk/issues/32603

Closes https://github.com/dart-lang/sdk/issues/32852

Change-Id: Ib79fbe7f043aa88f32bddad62d7656c638914b44
Reviewed-on: https://dart-review.googlesource.com/50944
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
2018-04-13 09:06:56 +00:00
Ryan Macnak b3c94b5d52 Revert "Reland "[VM] Introduction of type testing stubs - Part 1-4""
This reverts commit 34763bc4c9.

Bug: https://github.com/dart-lang/sdk/issues/32852
Change-Id: I2131907d7036644707d5109a951969fc48dd74e1
Reviewed-on: https://dart-review.googlesource.com/50842
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2018-04-11 22:42:59 +00:00
Martin Kustermann 34763bc4c9 Reland "[VM] Introduction of type testing stubs - Part 1-4"
Relands 165c583d57

    [VM] Introduction of type testing stubs - Part 1

    This CL:

      * Adds a field to [RawAbstractType] which will always hold a pointer
        to the entrypoint of a type testing stub

      * Makes this new field be initialized to a default stub whenever a
        instances are created (e.g. via Type::New(), snapshot reader, ...)

      * Makes the clustered snapshotter write a reference to the
        corresponding [RawInstructions] object when writing the field and do
        the reverse when reading it.

      * Makes us call the type testing stub for performing assert-assignable
        checks.

    To reduce unnecessary loads on callsites, we store the entrypoint of the
    type testing stubs directly in the type objects.  This means that the
    caller of type testing stubs can simply branch there without populating
    a code object first.  This also means that the type testing stubs
    themselves have no access to a pool and we therefore also don't hold on
    to the [Code] object, only the [Instruction] object is necessary.

    The type testing stubs do not setup a frame themselves and also have no
    safepoint.  In the case when the type testing stubs could not determine
    a positive answer they will tail-call a general-purpose stub.

    The general-purpose stub sets up a stub frame, tries to consult a
    [SubtypeTestCache] and bails out to runtime if this was unsuccessful.

    This CL is just the the first, for ease of reviewing.  The actual
    type-specialized type testing stubs will be generated in later CLs.

    Reviewed-on: https://dart-review.googlesource.com/44787

Relands f226c22424

    [VM] Introduction of type testing stubs - Part 2

    This CL starts building type testing stubs specialzed for [Type] objects
    we test against.

    More specifically, it adds support for:

      * Handling obvious fast cases on the call sites (while still having a
        call to stub for negative case)

      * Handling type tests against type parameters, by loading the value
        of the type parameter on the call sites and invoking it's type testing stub.

      * Specialzed type testing stubs for instantiated types where we can
        do [CidRange]-based subtype-checks.

        ==> e.g. String/List<dynamic>

      * Specialzed type testing stubs for instantiated types where we can
        do [CidRange]-based subclass-checks for the class and
        [CidRange]-based subtype-checks for the type arguments.

        ==> e.g. Widget<State>, where we know [Widget] is only extended and not
                 implemented.

      * Specialzed type testing stubs for certain non-instantiated types where we
        can do [CidRange]-based subclass-checks for the class and
        [CidRange]-based subtype-checks for the instantiated type arguments and
        cid based comparisons for type parameters.  (Note that this fast-case migth
        result in some false-negatives!)

        ==> e.g. _HashMapEntry<K, V>, where we know [_HashMapEntry] is only
                 extended and not implemented.

       This optimizes cases where the caller uses `new HashMap<A, B>()` and only
       uses `A` and `B` as key/values (and not subclasses of it).  The false-negative
       can occur when subtypes of A or B are used.  In such cases we fall back to the
       [SubtypeTestCache]-based imlementation.

    Reviewed-on: https://dart-review.googlesource.com/44788

Relands 25f98bcc75

    [VM] Introduction of type testing stubs - Part 3

    The changes include:

      * Make AssertAssignableInstr no longer have a call-summary, which
        helps methods with several parameter checks by not having to
        re-load/re-initialize type arguments registers

      * Lazily create SubtypeTestCaches: We already go to runtime to warm up
        the caches, so we now also create the caches on the first runtime
        call and patch the pool entries.

      * No longer load the destination name into a register: We only need
        the name when we throw an exception, so it is not on the hot path.
        Instead we let the runtime look at the call site, decoding a pool
        index from the instructions stream.  The destination name will be
        available in the pool, at a consecutive index to the subtype cache.

      * Remove the fall-through to N=1 case for probing subtypeing tests,
        since those will always be handled by the optimized stubs.

      * Do not generate optimized stubs for FutureOr<T> (so far it just
        falled-through to TTS).  We can make optimzed version of that later,
        but it requires special subtyping rules.

      * Local code quality improvement in the type-testing-stubs: Avoid
        extra jump at last case of cid-class-range checks.

    There are still a number of optimization opportunities we can do in
    future changes.

    Reviewed-on: https://dart-review.googlesource.com/46984

Relands 2c52480ec8

    [VM] Introduction of type testing stubs - Part 4

    In order to avoid generating type testing stubs for too many types in
    the system - and thereby potentially cause an increase in code size -
    this change introduces a smarter way to decide for which types we should
    generate optimized type testing stubs.

    The precompiler creates a [TypeUsageInfo] which we use to collect
    information.  More specifically:

       a) We collect the destination types for all type checks we emit
          (we do this inside AssertAssignableInstr::EmitNativeCode).

          -> These are types we might want to generate optimized type testing
             stubs for.

       b) We collect type argument vectors used in instance creations (we do
          this inside AllocateObjectInstr::EmitNativeCode) and keep a set of
          of used type argument vectors for each class.

    After the precompiler has finished compiling normal code we scan the set
    of destination types collected in a) for uninstantiated types (or more
    specifically, type parameter types).

    We then propagate the type argument vectors used on object allocation sites,
    which were collected in b), in order to find out what kind of types are flowing
    into those type parameters.

    This allows us to extend the set of types which we test against, by
    adding the types that flow into type parameters.

    We use this final augmented set of destination types as a "filter" when
    making the decision whether to generate an optimized type testing stub
    for a given type.

    Reviewed-on: https://dart-review.googlesource.com/48640

Issue https://github.com/dart-lang/sdk/issues/32603

Change-Id: I6d33d4ca3d5187a1eb1664078c003061855f0160
Reviewed-on: https://dart-review.googlesource.com/50482
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2018-04-10 12:20:10 +00:00
Martin Kustermann 1e997ee6b7 Revert "Reland "[VM] Introduction of type testing stubs - Part 1-4""
This reverts commit 8054409a02.

Reason for revert: Potential cause of flakes, not entirely clear yet if it was caused by this CL.

Change-Id: Icb119a107f22245ba2f303c7f2ae11f061f605f5
Reviewed-on: https://dart-review.googlesource.com/50261
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2018-04-09 14:29:07 +00:00
Martin Kustermann 8054409a02 Reland "[VM] Introduction of type testing stubs - Part 1-4"
Relands 165c583d57

    [VM] Introduction of type testing stubs - Part 1

    This CL:

      * Adds a field to [RawAbstractType] which will always hold a pointer
        to the entrypoint of a type testing stub

      * Makes this new field be initialized to a default stub whenever a
        instances are created (e.g. via Type::New(), snapshot reader, ...)

      * Makes the clustered snapshotter write a reference to the
        corresponding [RawInstructions] object when writing the field and do
        the reverse when reading it.

      * Makes us call the type testing stub for performing assert-assignable
        checks.

    To reduce unnecessary loads on callsites, we store the entrypoint of the
    type testing stubs directly in the type objects.  This means that the
    caller of type testing stubs can simply branch there without populating
    a code object first.  This also means that the type testing stubs
    themselves have no access to a pool and we therefore also don't hold on
    to the [Code] object, only the [Instruction] object is necessary.

    The type testing stubs do not setup a frame themselves and also have no
    safepoint.  In the case when the type testing stubs could not determine
    a positive answer they will tail-call a general-purpose stub.

    The general-purpose stub sets up a stub frame, tries to consult a
    [SubtypeTestCache] and bails out to runtime if this was unsuccessful.

    This CL is just the the first, for ease of reviewing.  The actual
    type-specialized type testing stubs will be generated in later CLs.

    Reviewed-on: https://dart-review.googlesource.com/44787

Relands f226c22424

    [VM] Introduction of type testing stubs - Part 2

    This CL starts building type testing stubs specialzed for [Type] objects
    we test against.

    More specifically, it adds support for:

      * Handling obvious fast cases on the call sites (while still having a
        call to stub for negative case)

      * Handling type tests against type parameters, by loading the value
        of the type parameter on the call sites and invoking it's type testing stub.

      * Specialzed type testing stubs for instantiated types where we can
        do [CidRange]-based subtype-checks.

        ==> e.g. String/List<dynamic>

      * Specialzed type testing stubs for instantiated types where we can
        do [CidRange]-based subclass-checks for the class and
        [CidRange]-based subtype-checks for the type arguments.

        ==> e.g. Widget<State>, where we know [Widget] is only extended and not
                 implemented.

      * Specialzed type testing stubs for certain non-instantiated types where we
        can do [CidRange]-based subclass-checks for the class and
        [CidRange]-based subtype-checks for the instantiated type arguments and
        cid based comparisons for type parameters.  (Note that this fast-case migth
        result in some false-negatives!)

        ==> e.g. _HashMapEntry<K, V>, where we know [_HashMapEntry] is only
                 extended and not implemented.

       This optimizes cases where the caller uses `new HashMap<A, B>()` and only
       uses `A` and `B` as key/values (and not subclasses of it).  The false-negative
       can occur when subtypes of A or B are used.  In such cases we fall back to the
       [SubtypeTestCache]-based imlementation.

    Reviewed-on: https://dart-review.googlesource.com/44788

Relands 25f98bcc75

    [VM] Introduction of type testing stubs - Part 3

    The changes include:

      * Make AssertAssignableInstr no longer have a call-summary, which
        helps methods with several parameter checks by not having to
        re-load/re-initialize type arguments registers

      * Lazily create SubtypeTestCaches: We already go to runtime to warm up
        the caches, so we now also create the caches on the first runtime
        call and patch the pool entries.

      * No longer load the destination name into a register: We only need
        the name when we throw an exception, so it is not on the hot path.
        Instead we let the runtime look at the call site, decoding a pool
        index from the instructions stream.  The destination name will be
        available in the pool, at a consecutive index to the subtype cache.

      * Remove the fall-through to N=1 case for probing subtypeing tests,
        since those will always be handled by the optimized stubs.

      * Do not generate optimized stubs for FutureOr<T> (so far it just
        falled-through to TTS).  We can make optimzed version of that later,
        but it requires special subtyping rules.

      * Local code quality improvement in the type-testing-stubs: Avoid
        extra jump at last case of cid-class-range checks.

    There are still a number of optimization opportunities we can do in
    future changes.

    Reviewed-on: https://dart-review.googlesource.com/46984

Relands 2c52480ec8

    [VM] Introduction of type testing stubs - Part 4

    In order to avoid generating type testing stubs for too many types in
    the system - and thereby potentially cause an increase in code size -
    this change introduces a smarter way to decide for which types we should
    generate optimized type testing stubs.

    The precompiler creates a [TypeUsageInfo] which we use to collect
    information.  More specifically:

       a) We collect the destination types for all type checks we emit
          (we do this inside AssertAssignableInstr::EmitNativeCode).

          -> These are types we might want to generate optimized type testing
             stubs for.

       b) We collect type argument vectors used in instance creations (we do
          this inside AllocateObjectInstr::EmitNativeCode) and keep a set of
          of used type argument vectors for each class.

    After the precompiler has finished compiling normal code we scan the set
    of destination types collected in a) for uninstantiated types (or more
    specifically, type parameter types).

    We then propagate the type argument vectors used on object allocation sites,
    which were collected in b), in order to find out what kind of types are flowing
    into those type parameters.

    This allows us to extend the set of types which we test against, by
    adding the types that flow into type parameters.

    We use this final augmented set of destination types as a "filter" when
    making the decision whether to generate an optimized type testing stub
    for a given type.

    Reviewed-on: https://dart-review.googlesource.com/48640

Issue https://github.com/dart-lang/sdk/issues/32603

Change-Id: I44a1d5d4b27454ae026aef2a301aada3dd399ea0
Reviewed-on: https://dart-review.googlesource.com/49861
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2018-04-09 11:25:36 +00:00
Martin Kustermann dbb1d3d44f Revert "[VM] Introduction of type testing stubs - Part 1-4"
This reverts commit 2c52480ec8.
This reverts commit 25f98bcc75.
This reverts commit f226c22424.
This reverts commit 165c583d57.

Change-Id: I3892d672b9ca0b0acc0b9b83c32ecc92355839c2
Reviewed-on: https://dart-review.googlesource.com/49843
Reviewed-by: Martin Kustermann <kustermann@google.com>
2018-04-06 08:35:01 +00:00
Martin Kustermann 25f98bcc75 [VM] Introduction of type testing stubs - Part 3
The changes include:

  * Make AssertAssignableInstr no longer have a call-summary, which
    helps methods with several parameter checks by not having to
    re-load/re-initialize type arguments registers

  * Lazily create SubtypeTestCaches: We already go to runtime to warm up
    the caches, so we now also create the caches on the first runtime
    call and patch the pool entries.

  * No longer load the destination name into a register: We only need
    the name when we throw an exception, so it is not on the hot path.
    Instead we let the runtime look at the call site, decoding a pool
    index from the instructions stream.  The destination name will be
    available in the pool, at a consecutive index to the subtype cache.

  * Remove the fall-through to N=1 case for probing subtypeing tests,
    since those will always be handled by the optimized stubs.

  * Do not generate optimized stubs for FutureOr<T> (so far it just
    falled-through to TTS).  We can make optimzed version of that later,
    but it requires special subtyping rules.

  * Local code quality improvement in the type-testing-stubs: Avoid
    extra jump at last case of cid-class-range checks.

There are still a number of optimization opportunities we can do in
future changes.

Issue https://github.com/dart-lang/sdk/issues/31798

Change-Id: I4dc5a8a49f939178fe74d44736ef69e4b9088e46
Reviewed-on: https://dart-review.googlesource.com/46984
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
2018-04-06 07:00:50 +00:00
Vyacheslav Egorov 8a179fb953 [VM, Compiler] Move compiler to a separate folder.
New folder structure (nested under vm/):

- compiler/
-   jit/         - JIT specific code
-   aot/         - AOT specific code
-   backend/     - all middle-end and back-end code (IL, flow graph)
-   assembler/   - assemblers and disassemblers
-   frontend/    - front ends (AST -> IL, Kernel -> IL)

compiler/README.md would be the documentation root for the compiler
pipeline

Bug: https://github.com/dart-lang/sdk/issues/30575
Change-Id: I2dfd9688793bff737f7632ddc77fca766875ce36
Reviewed-on: https://dart-review.googlesource.com/2940
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
2017-09-04 15:15:18 +00:00
Zachary Anderson 6cd8a79078 VM: Re-format to use at most one newline between functions
R=asiva@google.com

Review-Url: https://codereview.chromium.org/2974233002 .
2017-07-13 08:08:37 -07:00
Erik Corry 7d624bccd0 Revert "Do not rely on code patching on DBC for lazy deoptimization."
This reverts commit 6efb75b22f.
This is a speculative revert to try to make the tests green.

R=ahe@google.com
BUG=

Review-Url: https://codereview.chromium.org/2743903002 .
2017-03-10 10:01:58 +01:00
Todd Turnidge 6efb75b22f Do not rely on code patching on DBC for lazy deoptimization.
Instead we now patch the return address, like the other architectures.

R=rmacnak@google.com

Review-Url: https://codereview.chromium.org/2741553002 .
2017-03-09 14:10:43 -08:00
Zachary Anderson a1bcf051d8 clang-format runtime/vm
R=johnmccutchan@google.com

Review URL: https://codereview.chromium.org/2481873005 .
2016-11-08 13:54:47 -08:00
Ryan Macnak d8cc8644b1 Switchable call scheduling.
R=fschneider@google.com

Review URL: https://codereview.chromium.org/2404973002 .
2016-10-13 12:44:25 -07:00
Ryan Macnak 763daa9d06 Reapply "Lazy deopt without code patching."
When throwing to a frame scheduled for lazy deopt, update the continuation pc for that frame to be the catch handler.

Weaken new assert that the deopt pc belongs to the frame's code as the deopt pc for the last eager deopt in a function lies outside the code, after the call to the deopt stub.

R=fschneider@google.com

Review URL: https://codereview.chromium.org/2392613002 .
2016-10-03 11:31:48 -07:00
Ryan Macnak 4e9a473746 Revert "Lazy deopt without code patching."
This reverts commit 6cff17c59a.

Review URL: https://codereview.chromium.org/2382953004 .
2016-09-30 18:04:58 -07:00
Ryan Macnak 6cff17c59a Lazy deopt without code patching.
Keep a side table that maps a fp back to a deopt pc.

R=fschneider@google.com

Review URL: https://codereview.chromium.org/2380403003 .
2016-09-30 16:53:29 -07:00
Ryan Macnak 7ff2dd4117 Optimize AOT's switchable calls for the monomorphic case.
The call sequence is very similar to a classic IC call, except the guarded class and the target are loaded indirectly from the constant pool instead of as immediates. In the monomorphic case, we call directly to the expected target with a class check in the callee. In the unlinked, polymorphic and megamorphic cases, we call a stub; these case are now call-through instead of call-and-return.

Every code, except stubs involved in switchable calls, includes the class check sequence at the beginning. So we now distinguish between a checked and an unchecked entry point. Generated code except the switchable call continues to use the unchecked entry point.

PC offsets are calculated relative to the beginning of the instruction stream, rather than either entry point.

BUG=
R=fschneider@google.com

Review URL: https://codereview.chromium.org/2226893002 .
2016-08-12 11:18:35 -07:00
Stephen Adams d57599e6d1 x64: Decode more objects for code view.
In particular, the cmpq for parsing named optional arguments has the
object recognized.

BUG=
R=fschneider@google.com, johnmccutchan@google.com

Review URL: https://codereview.chromium.org/1888353002 .
2016-04-15 12:19:10 -07:00
Ryan Macnak 830bfe61b7 Precompilation: Generate instance calls as IC calls that can switch to Megamoprhic calls.
dart2js ARM -10.3% size

R=fschneider@google.com

Review URL: https://codereview.chromium.org/1418863003 .
2015-11-04 09:31:19 -08:00
Florian Schneider 4a653d9e17 VM: Store edge counters in one per-function array.
Reserve first element in the Function's ic_data_array to hold the edge
counter array.

Until now we had a one-element array per edge counter. This reduces memory
used by edge counters.

This CL allows to optimize code without having to have the unoptimized
code present.

Also, save space in Instruction by making place_id_ and lifetime_position_
a union. place_id_ is exclusively needed by Load/StoreOptimizer,
lifetime_position by the FlowGraphAllocator.

BUG=
R=asiva@google.com

Review URL: https://codereview.chromium.org//1343383003 .
2015-09-28 13:28:04 +02:00
Florian Schneider bac82e2592 VM: New calling convention for generated code.
Instead of calling code object directly, call indirectly and
pass the code object in a register. The object pool is then loaded from
the code object. This is another preparation step for making generated code
relocatable.

All non-ia32 platforms:
No entry patching.

ARM:
PC marker (now code object) moves to the same place as on x64 (below saved PP, above saved FP).
R9 is now used as PP, R10 as CODE_REG.

BUG=
R=koda@google.com, rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/1d343e5a7b75168fb6c9f86b64c55173cdbdc9b2

Review URL: https://codereview.chromium.org//1192103004 .
2015-09-19 13:21:09 +02:00
Florian Schneider 7af7a2db87 Revert "VM: New calling convention for generated code."
This reverts commit 1d343e5a7b.

Because of Windows test failures.

BUG=
TBR=whesse@google.com

Review URL: https://codereview.chromium.org//1343373003 .
2015-09-16 13:46:05 +02:00
Florian Schneider 1d343e5a7b VM: New calling convention for generated code.
Instead of calling code object directly, call indirectly and
pass the code object in a register. The object pool is then loaded from
the code object. This is another preparation step for making generated code
relocatable.

All non-ia32 platforms:
No entry patching.

ARM:
PC marker (now code object) moves to the same place as on x64 (below saved PP, above saved FP).
R9 is now used as PP, R10 as CODE_REG.

BUG=
R=rmacnak@google.com

Review URL: https://codereview.chromium.org//1192103004 .
2015-09-16 13:05:58 +02:00
Florian Schneider c05f1f9448 VM: Link native calls lazily.
The first invocation of a native functions goes into LinkNativeCall which
determines the final entry point and patches the object pool entry.

When running precompiled code, this makes deserializing the object
pool entries for native functions easy, they all initially point to
a single entry (LinkNativeCall).

BUG=
R=rmacnak@google.com

Review URL: https://codereview.chromium.org//1294113004 .
2015-08-21 11:37:50 +02:00
Florian Schneider b5966db69e VM: Clean up and fix bugs in instructions patterns
Fix bug in DecodeLoadWordFromPool: used Array::element_offset instead of ObjectPool::element_offset.
This only worked because they accidentally return the same value.

Remove virtual methods from InstructionsPatterns on ia32 and x64. Instead use a template for code reuse.
This avoids among others vtables for the *Pattern classes and saves >= 4K in VM binary code size.

BUG=
R=rmacnak@google.com

Review URL: https://codereview.chromium.org//1301963003 .
2015-08-21 09:31:36 +02:00
Florian Schneider fee4c530e1 Fix 64-bit build
Remove invalid cast from uword to uword.

TBR=srdjan@google.com

Review URL: https://codereview.chromium.org//1174673003.
2015-06-10 13:08:49 +02:00
Florian Schneider 265a54411a Object pool with support for untagged entries.
This adds meta-information to object pool entries to allow storing
untagged immediates or code addresses (ExternalLabel) directly.

This eliminates the need to generate extra code to preserve the LSB
when storing immediates as smis (x64, arm64).

BUG=

Review URL: https://codereview.chromium.org//1175523002.
2015-06-10 11:41:22 +02:00
Florian Schneider 9191b76fd2 VM: Set breakpoints on x64 and arm64 without patching code.
Instead of changing the generated code, change the target of calls
by changing the corresponding entry in the constant pool. Patchable
call sites can't share constant pool entries for now.
x64 and arm64 already had support for patching call targets in the
constant pool, but the debugger used to change the code instead.

This eliminates the fixed debugger stub entries in every constant pool.

R=hausner@google.com

Review URL: https://codereview.chromium.org//1137313002
2015-05-18 15:03:02 +02:00
fschneider@google.com 4201900778 VM: Small generated code size improvements on x64.
Addtional cleanup in code_patcher on all platforms.

R=zra@google.com

Review URL: https://codereview.chromium.org//829133006

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@42700 260f80e4-7a28-3924-810f-c04153c831b5
2015-01-08 16:42:05 +00:00
koda@google.com c6bf5f2381 Support verified heap pointer writes on x64.
Port of r41607, r41700, and upcoming change:
https://codereview.chromium.org/721233002/

R=iposva@google.com

Review URL: https://codereview.chromium.org//727623002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@41787 260f80e4-7a28-3924-810f-c04153c831b5
2014-11-17 18:09:42 +00:00
regis@google.com e0ab99b0b2 Remember all deopt reasons in ic_data, not just the last one.
Remember if a JS warning was issued in ic_data.
Save a word in ic_data on 64-bit platforms.

R=iposva@google.com, srdjan@google.com

Review URL: https://codereview.chromium.org//254723003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@35457 260f80e4-7a28-3924-810f-c04153c831b5
2014-04-25 23:45:14 +00:00
hausner@google.com b4f0bf5998 Fix debugger stub patching on x64 architecture
Instead of patching the entry in the object pool, patch the offset
into the pool at the call site.

SIMARM and SIMMIPS will have to be fixed the same way in a later change.

R=iposva@google.com

Review URL: https://codereview.chromium.org//131853006

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@31812 260f80e4-7a28-3924-810f-c04153c831b5
2014-01-14 23:27:13 +00:00
srdjan@google.com d78737298c Last cleanup int -> intptr_t. Also removed a hack (boolean is not an integer).
R=asiva@google.com

Review URL: https://codereview.chromium.org//26345002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@28372 260f80e4-7a28-3924-810f-c04153c831b5
2013-10-08 18:54:00 +00:00
kmillikin@google.com b9715d23d0 x64: Use a short encoding of addq and subq for 32-bit immediates.
BUG=https://code.google.com/p/dart/issues/detail?id=13681
R=fschneider@google.com

Review URL: https://codereview.chromium.org//25491002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@28087 260f80e4-7a28-3924-810f-c04153c831b5
2013-10-01 11:17:44 +00:00
kmillikin@google.com e375053d2f Pattern match on generated code to find edge counters.
In unoptimized code, use platform-specific pattern matching on generated
code to find edge counter arrays.  Previously we searched pointer offsets,
but that does not work on platforms that encode the edge counters as indexes
into an object pool (i.e., x64, ARM, MIPS).

BUG=
R=fschneider@google.com, zra@google.com

Review URL: https://codereview.chromium.org//24744002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@28085 260f80e4-7a28-3924-810f-c04153c831b5
2013-10-01 10:22:47 +00:00
zra@google.com df2054dae7 Sets a register aside on x64 for use as a pool-pointer. It is loaded and restored from the code object on Frame entry and exit. All LoadObject calls that can, and many calls and jumps through ExternalLabels now use the pool-pointer. The --compiler-stats flag when running dart2js indicates that code size is reduced ~13%, and more is probably possible.
R=fschneider@google.com, srdjan@google.com

Review URL: https://codereview.chromium.org//22825023

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@27295 260f80e4-7a28-3924-810f-c04153c831b5
2013-09-09 15:39:26 +00:00
srdjan@google.com 5781d7cc84 Collect both arguments for math's min/max static functions. Later that information will be used to inline the operation if possible.
R=regis@google.com

Review URL: https://codereview.chromium.org//19774007

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@25225 260f80e4-7a28-3924-810f-c04153c831b5
2013-07-19 16:49:29 +00:00
srdjan@google.com 7d945c593a Remove skip_static_calls_ as it uses an obsolete way to check for uncalled static calls. Will be replaced by ICData tracking.
Add two different PCDescriptors to differentiate between optimized and unoptimized static calls (the former loads args. descr, the later loads ICData before calling).
Populate static call's ic_data field when optimizing.

R=asiva@google.com

Review URL: https://codereview.chromium.org//17723002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@24433 260f80e4-7a28-3924-810f-c04153c831b5
2013-06-25 21:31:37 +00:00
srdjan@google.com fa7817bf79 Change static calls in unoptimized code to always call via a stub. Using ICData, the call count of static calls is collected as well.
TODO: Use call frequency to guide inlining.

R=asiva@google.com, hausner@google.com, zra@google.com

Review URL: https://codereview.chromium.org//17554003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@24307 260f80e4-7a28-3924-810f-c04153c831b5
2013-06-21 23:35:10 +00:00
srdjan@google.com 47de186e76 Store arguments descriptor in ICData. Remove loading of arguments descriptor at unoptimized call site (the ones using ICData).
R=asiva@google.com, zra@google.com

Review URL: https://codereview.chromium.org//17421003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@24239 260f80e4-7a28-3924-810f-c04153c831b5
2013-06-20 16:29:39 +00:00
hausner@google.com 80c7ad1070 Implement breakpoint for closure calls
Introduce a new PcDescriptor kind to distinguish closure calls from other runtime calls. The debugger can patch these calls to set a breakpoint. When stepping into a closure call, the debugger must fish out the closure object from the stack, find the function and set breakpoints in it.

Arm and Mips breakpoint stubs are not implemented yet. ia32 and x64 stubs tested by hand. Automated test to follow.

R=srdjan@google.com

Review URL: https://codereview.chromium.org//14858033

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@22596 260f80e4-7a28-3924-810f-c04153c831b5
2013-05-10 21:06:04 +00:00
regis@google.com deeb192b03 Cleanup deoptimization code to make it architecture independent (in progress).
Implement some optimizing code on ARM in order to debug the above cleanup using
inline_stack_frame_test (still skipped in the vm status file).

This is not quite working yet, because CompilerDeoptInfo::CreateDeoptInfo
makes assumptions about the stack layout that are not valid for ARM or MIPS.
This will be cleaned up in a following cl.

R=srdjan@google.com, zra@google.com

Review URL: https://codereview.chromium.org//14812005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@22386 260f80e4-7a28-3924-810f-c04153c831b5
2013-05-03 18:39:40 +00:00