• Ross McIlroy's avatar
    [TurboProp] Remove unreachable successor basic blocks from schedule. · 4a2ef63c
    Ross McIlroy authored
    Effect-control-linearizer will update a basic block to connect it
    directly to the end node if it has an Unreachable node. Usually the
    block would already have been connected directly to end (via a Throw
    node) already, however in some cases it can be connected indirectly
    (via a branch, where both end in a throw node).
    
    If this happens, and the Effect-control-linearizer is maintaining the
    schedule (e.g., for TurboProp), it will cause the end block to have
    unreachable predecessor blocks, which can cause issues with the
    register allocator.
    
    To fix this, have the BasicBlockUpdater remove all successor blocks
    from the schedule, when they become Unreachable. Also add some tests
    to cover this in effect-control-linearizer-unittests.
    
    BUG=v8:10332,v8:9684
    
    Change-Id: Ibce140e6d1f61751a86247e6f8c36075723a1e55
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2120537
    Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
    Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#66994}
    4a2ef63c
node-properties.cc 19.5 KB