1. 24 Apr, 2019 1 commit
    • Jakob Gruber's avatar
      [coverage] Reduce IncBlockCounter overhead · ae6a47ba
      Jakob Gruber authored
      When collecting JS block coverage, we track block execution counts on
      so-called CoverageInfo objects. Generated bytecode and native code
      contains inlined snippets of code to increment the appropriate
      counters.
      
      These used to be implemented as calls to the IncBlockCounter runtime
      function. Each call incurred the entire CEntry overhead.
      
      This CL reduces that overhead by moving logic over into a new
      IncBlockCounter TFS builtin. The builtin is called directly from
      bytecode, and lowered to the same builtin call for optimized code.
      
      Drive-by: Tweak CoverageInfo layout to generate faster code.
      
      Tbr: jarin@chromium.org
      Bug: v8:9149, v8:6000
      Change-Id: I2d7cb0db649edf7c56b5ef5a4683d27b1c34605c
      Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1571420Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
      Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
      Reviewed-by: 's avatarPeter Marshall <petermarshall@chromium.org>
      Commit-Queue: Jakob Gruber <jgruber@chromium.org>
      Cr-Commit-Position: refs/heads/master@{#60981}
      ae6a47ba