1. 21 May, 2020 1 commit
    • Seth Brenith's avatar
      [diagnostics] Support --turbo-profiling for builtins · 18c73676
      Seth Brenith authored
      Currently, if d8 is run with the --turbo-profiling flag, it prints info
      about every TurboFan-compiled function. This info includes the number of
      times that each basic block in the function was run. It also includes
      text representations of the function's schedule and code, so that the
      person reading the output can associate counters with blocks of code.
      
      The data about each function is currently stored in a
      BasicBlockProfiler::Data instance, which is attached to a list owned by
      the singleton BasicBlockProfiler. Each Data contains an
      std::vector<uint32_t> which represents how many times each block in the
      function has executed. The generated code for each block uses a raw
      pointer into the storage of that vector to implement incrementing the
      counter.
      
      With this change, if you compile with v8_enable_builtins_profiling and
      then run with --turbo-profiling, d8 will print that same info about
      builtins too.
      
      In order to generate code that can survive being serialized to a
      snapshot and reloaded, this change uses counters in the JS heap instead
      of a std::vector outside the JS heap. The steps for instrumentation are
      as follows:
      
      1. Between scheduling and instruction selection, add code to increment
         the counter for each block. The counters array doesn't yet exist at
         this point, and allocation is disallowed, so at this point the code
         refers to a special marker value.
      2. During finalization of the code, allocate a BasicBlockProfilingData
         object on the JS heap containing data equivalent to what is stored in
         BasicBlockProfiler::Data. This includes a ByteArray that is big
         enough to store the counters for each block.
      3. Patch the reference in the BuiltinsConstantsTableBuilder so that
         instead of referring to the marker object, it now refers to this
         ByteArray. Also add the BasicBlockProfilingData object to a list that
         is attached to the heap roots so it can be easily accessed for
         printing.
      
      Because these steps include modifying the BuiltinsConstantsTableBuilder,
      this procedure is only applicable to builtins. Runtime-generated code
      still uses raw pointers into std::vector instances. In order to keep
      divergence between these code paths to a minimum, most work is done
      referring to instances of BasicBlockProfiler::Data (the C++ class), and
      functions are provided to copy back and forth between that type and
      BasicBlockProfilingData (the JS heap object).
      
      This change is intended only to make --turbo-profiling work consistently
      on more kinds of functions, but with some further work, this data could
      form the basis for:
      - code coverage info for fuzzers, and/or
      - hot-path info for profile-guided optimization.
      
      Bug: v8:10470, v8:9119
      Change-Id: Ib556a5bc3abe67cdaa2e3ee62702a2a08b11cb61
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2159738
      Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
      Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#67944}
      18c73676
  2. 28 Oct, 2019 1 commit
    • Seth Brenith's avatar
      [torque] Use generated instance types, part 1 · 91e6421c
      Seth Brenith authored
      This change begins making use of the fact that Torque now knows about
      the relationship between classes and instance types, to replace a few
      repetitive lists:
      
      - Instance type checkers (single and range), defined in
        src/objects/instance-type.h
      - Verification dispatch in src/diagnostics/objects-debug.cc
      - Printer dispatch in src/diagnostics/objects-printer.cc
      - Postmortem object type detection in
        tools/debug_helper/get-object-properties.cc
      
      Torque is updated to generate four macro lists for the instance types,
      representing all of the classes separated in two dimensions: classes
      that correspond to a single instance type versus those that have a
      range, and classes that are fully defined in Torque (with fields and
      methods inside '{}') versus those that are only declared. The latter
      distinction is useful because fully-defined classes are guaranteed to
      correspond to real C++ classes, whereas only-declared classes are not.
      
      A few other changes were required to make the lists above work:
      
      - Renamed IsFiller to IsFreeSpaceOrFiller to better reflect what it does
        and avoid conflicts with the new macro-generated IsFiller method. This
        is the part I'm most worried about: I think the new name is an
        improvement for clarity and consistency, but I could imagine someone
        typing IsFiller out of habit and introducing a bug. If we'd prefer to
        keep the name IsFiller, my other idea is to rename FreeSpace to
        VariableSizeFiller and Filler to FixedSizeFiller.
      - Made Tuple3 extend from Struct, not Tuple2, because IsTuple2 is
        expected to check for only TUPLE2_TYPE and not include TUPLE3_TYPE.
      - Normalized the dispatched behavior for BigIntBase and HeapNumber.
      - Added a few new object printers.
      
      Bug: v8:7793
      Change-Id: I5462bb105f8a314baa59bd6ab6ab6215df6f313c
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1860314
      Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
      Reviewed-by: 's avatarJakob Kummerow <jkummerow@chromium.org>
      Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
      Reviewed-by: 's avatarDan Elphick <delphick@chromium.org>
      Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#64597}
      91e6421c
  3. 11 Oct, 2019 1 commit
    • Seth Brenith's avatar
      [torque] Generate instance types · 8c7ae314
      Seth Brenith authored
      Design doc:
      https://docs.google.com/document/d/1ZU6rCvF2YHBGMLujWqqaxlPsjFfjKDE9C3-EugfdlAE/edit
      
      Changes from the design doc:
      - Changed to use 'class' declarations rather than 'type' declarations
        for things that need instance types but whose layout is not known to
        Torque. These declarations end with a semicolon rather than having a
        full set of methods and fields surrounded by {}. If the class's name
        should not be treated as a class name in generated output (because
        it's actually a template, or doesn't exist at all), we use the
        standard 'generates' clause to declare the most appropriate C++ class.
      - Removed @instanceTypeName.
      - @highestInstanceType became @highestInstanceTypeWithinParentClassRange
        to indicate a semantic change: it no longer denotes the highest
        instance type globally, but only within the range of values for its
        immediate parent class. This lets us use it for Oddball, which is
        expected to be the highest primitive type.
      - Added new abstract classes JSCustomElementsObject and JSSpecialObject
        to help with some range checks.
      - Added @lowestInstanceTypeWithinParentClassRange so we can move the new
        classes JSCustomElementsObject and JSSpecialObject to the beginning of
        the JSObject range. This seems like the least-brittle way to establish
        ranges that also include JSProxy (and these ranges are verified with
        static assertions in instance-type.h).
      - Renamed @instanceTypeValue to @apiExposedInstanceTypeValue.
      - Renamed @instanceTypeFlags to @reserveBitsInInstanceType.
      
      This change introduces the new annotations and adds the ability for
      Torque to assign instance types that satisfy those annotations. Torque
      now emits two new macros:
      - TORQUE_ASSIGNED_INSTANCE_TYPES, which is used to define the
        InstanceType enumeration
      - TORQUE_ASSIGNED_INSTANCE_TYPE_LIST, which replaces the non-String
        parts of INSTANCE_TYPE_LIST
      
      The design document mentions a couple of other macro lists that could
      easily be replaced, but I'd like to defer those to a subsequent checkin
      because this one is already pretty large.
      
      Bug: v8:7793
      Change-Id: Ie71d93a9d5b610e62be0ffa3bb36180c3357a6e8
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1757094
      Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
      Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
      Reviewed-by: 's avatarSathya Gunasekaran  <gsathya@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#64258}
      8c7ae314
  4. 24 May, 2019 1 commit
  5. 14 May, 2019 1 commit
  6. 29 Mar, 2019 1 commit
  7. 18 Mar, 2019 1 commit
  8. 18 Jan, 2019 1 commit
  9. 09 Jan, 2019 1 commit
  10. 20 Dec, 2018 1 commit
  11. 18 Dec, 2018 2 commits