1. 17 Feb, 2021 1 commit
    • Seth Brenith's avatar
      Reland "[interpreter] Short Star bytecode" · 7be64db4
      Seth Brenith authored
      This is a reland of cf93071c
      
      Original change's description:
      > [interpreter] Short Star bytecode
      >
      > Design doc:
      > https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
      >
      > This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
      > that we can use a single byte to represent the common operation of
      > storing to a low-numbered register. This generally reduces the quantity
      > of bytecode generated on web sites by 8-9%.
      >
      > In order to not degrade speed, a couple of other changes are required:
      >
      > The existing lookahead logic to check for Star after certain other
      > bytecode handlers is updated to check for these new short Star codes
      > instead. Furthermore, that lookahead logic is updated to contain its own
      > copy of the dispatch jump rather than merging control flow with the
      > lookahead-failed case, to improve branch prediction.
      >
      > A bunch of constants use bytecode size in bytes as a proxy for the size
      > or complexity of a function, and are adjusted downward proportionally to
      > the decrease in generated bytecode size.
      >
      > Other small drive-by fix: update generate-bytecode-expectations to emit
      > \n instead of \r\n on Windows.
      >
      > Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
      > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
      > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
      > Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      > Cr-Commit-Position: refs/heads/master@{#72773}
      
      Change-Id: I1afb670c25694498b3989de615858f984a8c7f6f
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2698057
      Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
      Reviewed-by: 's avatarMythri Alle <mythria@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#72821}
      7be64db4
  2. 16 Feb, 2021 2 commits
    • Leszek Swirski's avatar
      Revert "[interpreter] Short Star bytecode" · 08a49bbe
      Leszek Swirski authored
      This reverts commit cf93071c.
      
      Reason for revert: Speculative revert because of Mac4 GC stress failure: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Mac64%20GC%20Stress/16697/overview
      
      Original change's description:
      > [interpreter] Short Star bytecode
      >
      > Design doc:
      > https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
      >
      > This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
      > that we can use a single byte to represent the common operation of
      > storing to a low-numbered register. This generally reduces the quantity
      > of bytecode generated on web sites by 8-9%.
      >
      > In order to not degrade speed, a couple of other changes are required:
      >
      > The existing lookahead logic to check for Star after certain other
      > bytecode handlers is updated to check for these new short Star codes
      > instead. Furthermore, that lookahead logic is updated to contain its own
      > copy of the dispatch jump rather than merging control flow with the
      > lookahead-failed case, to improve branch prediction.
      >
      > A bunch of constants use bytecode size in bytes as a proxy for the size
      > or complexity of a function, and are adjusted downward proportionally to
      > the decrease in generated bytecode size.
      >
      > Other small drive-by fix: update generate-bytecode-expectations to emit
      > \n instead of \r\n on Windows.
      >
      > Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
      > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
      > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
      > Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      > Cr-Commit-Position: refs/heads/master@{#72773}
      
      TBR=rmcilroy@chromium.org,mythria@chromium.org,seth.brenith@microsoft.com
      
      Change-Id: I0162b9400861b90bacef27cca9aebc8ab9d74c10
      No-Presubmit: true
      No-Tree-Checks: true
      No-Try: true
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2697350Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
      Commit-Queue: Leszek Swirski <leszeks@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#72777}
      08a49bbe
    • Seth Brenith's avatar
      [interpreter] Short Star bytecode · cf93071c
      Seth Brenith authored
      Design doc:
      https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
      
      This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
      that we can use a single byte to represent the common operation of
      storing to a low-numbered register. This generally reduces the quantity
      of bytecode generated on web sites by 8-9%.
      
      In order to not degrade speed, a couple of other changes are required:
      
      The existing lookahead logic to check for Star after certain other
      bytecode handlers is updated to check for these new short Star codes
      instead. Furthermore, that lookahead logic is updated to contain its own
      copy of the dispatch jump rather than merging control flow with the
      lookahead-failed case, to improve branch prediction.
      
      A bunch of constants use bytecode size in bytes as a proxy for the size
      or complexity of a function, and are adjusted downward proportionally to
      the decrease in generated bytecode size.
      
      Other small drive-by fix: update generate-bytecode-expectations to emit
      \n instead of \r\n on Windows.
      
      Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
      Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
      Cr-Commit-Position: refs/heads/master@{#72773}
      cf93071c
  3. 10 Feb, 2020 1 commit
  4. 11 Nov, 2019 1 commit
    • Jakob Gruber's avatar
      [interpreter] Move function-entry stack check to start of bytecode array · cebfde67
      Jakob Gruber authored
      The function-entry stack check should dominate all other
      instructions in a function. Prior to this CL it was possible to create
      paths not including a stack check due to SwitchOnGeneratorState: the
      generator-creation branch had a stack check, while generator-resume
      branches did not.
      
        0 : af fb 00 01       SwitchOnGeneratorState r0, [0], [1] { 0: @22 }
        4 : 27 fe fa          Mov <closure>, r1
        7 : 27 02 f9          Mov <this>, r2
       10 : 64 0a fa 02       InvokeIntrinsic [_CreateJSGeneratorObject], r1-r2
       14 : 26 fb             Star r0
       16 : a7                StackCheck
       17 : b0 fb fb 01 00    SuspendGenerator r0, r0-r0, [0]
       22 : b1 fb fb 01       ResumeGenerator r0, r0-r0
                              [... no stack check here ...]
      
      This CL moves the stack check to the beginning of the bytecode array,
      i.e. before SwitchOnGeneratorState.
      
      Bug: chromium:1020031
      Change-Id: I8ba8cba99611ddbe50c76023129d926cc84b1d5e
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1903440Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
      Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
      Commit-Queue: Jakob Gruber <jgruber@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#64888}
      cebfde67
  5. 18 Jul, 2017 1 commit
  6. 14 Jul, 2017 1 commit
    • Alexey Kozyatinskiy's avatar
      [inspector] improve return position of explicit return in non-async function · 08965860
      Alexey Kozyatinskiy authored
      Goal of this CL: explicit return from non-async function has position after
      return expression as return position (will unblock [1]).
      
      BytecodeArrayBuilder has SetStatementPosition and SetExpressionPosition methods.
      If one of these methods is called then next generated bytecode will get passed
      position. It's general treatment for most cases.
      Unfortunately it doesn't work for Returns:
      - debugger requires source positions exactly on kReturn bytecode in stepping
        implementation,
      - BytecodeGenerator::BuildReturn and BytecodeGenerator::BuildAsyncReturn
        generates more then one bytecode and general solution will put return position
        on first generated bytecode,
      - it's not easy to split BuildReturn function into two parts to allow something
        like following in BytecodeGenerator::VisitReturnStatement since generated
        bytecodes are actually controlled by execution_control().
      ..->BuildReturnPrologue();
      ..->SetReturnPosition(stmt);
      ..->Return();
      
      In this CL we pass ReturnStatement through ExecutionControl and use it for
      position when we emit return bytecode right here.
      
      So this CL only will improve return position for returns inside of non-async
      functions, I'll address async functions later.
      
      [1] https://chromium-review.googlesource.com/c/543161/
      
      Change-Id: Iede512c120b00c209990bf50c20e7d23dc0d65db
      Reviewed-on: https://chromium-review.googlesource.com/560738
      Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
      Reviewed-by: 's avatarAdam Klein <adamk@chromium.org>
      Reviewed-by: 's avatarMichael Starzinger <mstarzinger@chromium.org>
      Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
      Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#46687}
      08965860
  7. 06 Jun, 2017 1 commit
  8. 30 May, 2017 1 commit
    • Aleksey Kozyatinskiy's avatar
      [inspector] moved var initialization break location before init expression (reland) · fb6a094d
      Aleksey Kozyatinskiy authored
      This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
      Benefits (see test for details):
       - only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
       - removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
       
      TBR=dgozman@chromium.org,rmcilroy@chromium.org,machenbach@chromium.org,marja@chromium.org,kozyatinskiy@chromium.org,devtools-reviews@chromium.org,v8-reviews@googlegroups.com
      # Not skipping CQ checks because original CL landed > 1 day ago.
      Bug: v8:5909
      
      Change-Id: Ie84fa79afeed09e28cf8478ba610a0cfbfdfc294
      Reviewed-on: https://chromium-review.googlesource.com/518116
      Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
      Reviewed-by: 's avatarAleksey Kozyatinskiy <kozyatinskiy@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#45598}
      fb6a094d
  9. 29 May, 2017 1 commit
    • Michael Achenbach's avatar
      Revert "[inspector] moved var initialization break location before init expression" · ee1db48c
      Michael Achenbach authored
      This reverts commit 7a9cc704.
      
      Reason for revert: Changes layout tests:
      https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/15882
      
      This is about:
      inspector/sources/debugger/source-frame-inline-breakpoint-decorations.html
      
      Original change's description:
      > [inspector] moved var initialization break location before init expression
      > 
      > This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
      > Benefits (see test for details):
      > - only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
      > - removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
      > 
      > Bug: v8:5909
      > Change-Id: I039d911903a2826c9859710a63ab0462c992e11b
      > Reviewed-on: https://chromium-review.googlesource.com/513926
      > Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
      > Reviewed-by: Marja Hölttä <marja@chromium.org>
      > Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
      > Cr-Commit-Position: refs/heads/master@{#45530}
      
      TBR=dgozman@chromium.org,marja@chromium.org,kozyatinskiy@chromium.org
      # Not skipping CQ checks because original CL landed > 1 day ago.
      Bug: v8:5909
      
      Change-Id: Ibf84401e8050d3c84db219d983de2c6bba0f697f
      Reviewed-on: https://chromium-review.googlesource.com/518102Reviewed-by: 's avatarMichael Achenbach <machenbach@chromium.org>
      Commit-Queue: Michael Achenbach <machenbach@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#45547}
      ee1db48c
  10. 25 May, 2017 1 commit
  11. 08 May, 2017 1 commit
    • Adam Klein's avatar
      Skip hole initialization of lexical variables when possible · ededfcd2
      Adam Klein authored
      This patch expands scope analysis to skip hole initialization
      when it can be determined statically that no hole checks will
      be generated at runtime.
      
      Two conditions must be met to safely eliminate hole initialization:
        - There must not exist a VariableProxy referencing this Variable
          whose HoleCheckMode is kRequired
        - The Variable must be stack allocated; any other allocation implies
          that it may be accessed from not-yet-analyzed scopes (other modules,
          inner functions, or eval code) and that code may require
          hole checks.
      
      The new logic required removing debug code in full-codegen which is
      now incorrect in some cases.
      
      Also fixed Variable's bitfield helpers to take no more space than needed.
      
      Bug: chromium:651637
      Change-Id: Ie5ac326af4e05b7a5c3c37cd4d0afba6a51a504d
      Reviewed-on: https://chromium-review.googlesource.com/494006
      Commit-Queue: Adam Klein <adamk@chromium.org>
      Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
      Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
      Reviewed-by: 's avatarMichael Starzinger <mstarzinger@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#45170}
      ededfcd2
  12. 03 May, 2017 1 commit
  13. 25 Jan, 2017 1 commit
  14. 20 Oct, 2016 1 commit
    • adamk's avatar
      [ignition] Eliminate hole checks where statically possible for loads and stores · 35a3ccbf
      adamk authored
      Move hole check logic from full-codegen into scope analysis, and store the
      "needs hole check" bit on VariableProxy. This makes it easy to re-use in
      any backend: it will be trivial to extend the use of this logic in, e.g.,
      full-codegen variable stores.
      
      While changing the signatures of the variable loading/storing methods in
      Ignition, I took the liberty of replacing the verb "Visit" with "Build", since these
      are not part of AST visiting.
      
      BUG=v8:5460
      
      Review-Url: https://chromiumcodereview.appspot.com/2411873004
      Cr-Commit-Position: refs/heads/master@{#40479}
      35a3ccbf
  15. 04 Oct, 2016 1 commit
  16. 30 Sep, 2016 1 commit
    • rmcilroy's avatar
      [Interpreter] Replace BytecodeRegisterAllocator with a simple bump pointer. · 27fe988b
      rmcilroy authored
      There are only a few occasions where we allocate a register in an outer
      expression allocation scope, which makes the costly free-list approach
      of the BytecodeRegisterAllocator unecessary. This CL replaces all
      occurrences with moves to the accumulator and stores to a register
      allocated in the correct scope. By doing this, we can simplify the
      BytecodeRegisterAllocator to be a simple bump-pointer allocator
      with registers released in the same order as allocated.
      
      The following changes are also made:
       - Make BytecodeRegisterOptimizer able to use registers which have been
         unallocated, but not yet reused
       - Remove RegisterExpressionResultScope and rename
         AccumulatorExpressionResultScope to ValueExpressionResultScope
       - Introduce RegisterList to represent consecutive register
         allocations, and use this for operands to call bytecodes.
      
      By avoiding the free-list handling, this gives another couple of
      percent on CodeLoad.
      
      BUG=v8:4280
      
      Review-Url: https://codereview.chromium.org/2369873002
      Cr-Commit-Position: refs/heads/master@{#39905}
      27fe988b
  17. 06 Sep, 2016 1 commit
    • leszeks's avatar
      [Interpreter] Remove constant pool type in tests · b28b7e13
      leszeks authored
      For historical reasons, the interpreter's bytecode expectations tests
      required a type for the constant pool. This had two disadvantages:
      
       1. Strings and numbers were not visible in mixed pools, and
       2. Mismatches of pool types (e.g. when rebaselining) would cause parser
          errors
      
      This removes the pool types, making everything 'mixed', but appending
      the values to string and number valued constants. Specifying a pool type
      in the *.golden header now prints a warning (for backwards compatibility).
      
      BUG=v8:5350
      
      Review-Url: https://codereview.chromium.org/2310103002
      Cr-Commit-Position: refs/heads/master@{#39216}
      b28b7e13
  18. 19 Jul, 2016 1 commit
  19. 18 Jul, 2016 2 commits
  20. 09 Jun, 2016 1 commit
  21. 27 May, 2016 1 commit
  22. 23 May, 2016 1 commit
    • oth's avatar
      [Interpreter] Preserve source positions in peephole optimizer. · e43fbde7
      oth authored
      The original peephole optimizer logic in the BytecodeArrayBuilder did
      not respect source positions as it was written before there were
      bytecode source positions. This led to some minor differences to
      FCG and was problematic when combined with pending bytecode
      optimizations. This change makes the new peephole optimizer fully
      respect source positions.
      
      BUG=v8:4280
      LOG=N
      
      Review-Url: https://codereview.chromium.org/1998203002
      Cr-Commit-Position: refs/heads/master@{#36439}
      e43fbde7
  23. 11 May, 2016 1 commit
  24. 21 Mar, 2016 1 commit
    • oth's avatar
      [interpreter] Add support for scalable operands. · 48d082af
      oth authored
      This change introduces wide prefix bytecodes to support wide (16-bit)
      and extra-wide (32-bit) operands. It retires the previous
      wide-bytecodes and reduces the number of operand types.
      
      Operands are now either scalable or fixed size. Scalable operands
      increase in width when a bytecode is prefixed with wide or extra-wide.
      
      The bytecode handler table is extended to 256*3 entries. The
      first 256 entries are used for bytecodes with 8-bit operands,
      the second 256 entries are used for bytecodes with operands that
      scale to 16-bits, and the third group of 256 entries are used for
      bytecodes with operands that scale to 32-bits.
      
      LOG=N
      BUG=v8:4747,v8:4280
      
      Review URL: https://codereview.chromium.org/1783483002
      
      Cr-Commit-Position: refs/heads/master@{#34955}
      48d082af
  25. 25 Feb, 2016 1 commit
    • ssanfilippo's avatar
      [Interpreter] Refactor bytecode generator test suite. · 6ae03059
      ssanfilippo authored
      Bytecode expectations have been moved to external (.golden) files,
      one per test. Each test in the suite builds a representation of the
      the compiled bytecode using BytecodeExpectationsPrinter. The output is
      then compared to the golden file. If the comparision fails, a textual
      diff can be used to identify the discrepancies.
      
      Only the test snippets are left in the cc file, which also allows to
      make it more compact and meaningful. Leaving the snippets in the cc
      file was a deliberate choice to allow keeping the "truth" about the
      tests in the cc file, which will rarely change, as opposed to golden
      files.
      
      Golden files can be generated and kept up to date using
      generate-bytecode-expectations, which also means that the test suite
      can be batch updated whenever the bytecode or golden format changes.
      
      The golden format has been slightly amended (no more comments about
      `void*`, add size of the bytecode array) following the consideration
      made while converting the tests.
      
      There is also a fix: BytecodeExpectationsPrinter::top_level_ was left
      uninitialized, leading to undefined behaviour.
      
      BUG=v8:4280
      LOG=N
      
      Review URL: https://codereview.chromium.org/1717293002
      
      Cr-Commit-Position: refs/heads/master@{#34285}
      6ae03059