• Tobias Tebbi's avatar
    Revert "Reland^2 "[turbofan] eagerly prune None types and deadness from the graph"" · 738e773b
    Tobias Tebbi authored
    This reverts commit 6ddb5e7d.
    
    Reason for revert: chromium:772873 chromium:772872
    
    Original change's description:
    > Reland^2 "[turbofan] eagerly prune None types and deadness from the graph"
    > 
    > Now, the EffectControlLinearizer connects all occurrences of Unreachable to the 
    > graph end. This fixes issues with later phases running DeadCodeElimination and
    > introducing new DeadValue nodes when processing uses of Unreachable.
    > 
    > This is a reland of 3c4bc27f
    > Original change's description:
    > > Reland "[turbofan] eagerly prune None types and deadness from the graph"
    > > 
    > > This is a reland of e1cdda25
    > > Original change's description:
    > > > [turbofan] eagerly prune None types and deadness from the graph
    > > > 
    > > > In addition to using the {Dead} node to prune dead control nodes and nodes that 
    > > > depend on them, we introduce a {DeadValue} node representing an impossible value 
    > > > that can occur at any position in the graph. The extended {DeadCodeElimination}
    > > > prunes {DeadValue} and its uses, inserting a crashing {Unreachable} node into
    > > > the effect chain when possible. The remaining uses of {DeadValue} are handled
    > > > in {EffectControlLinearizer}, where we always have access to the effect chain.
    > > > In addition to explicitly introduced {DeadValue} nodes, we consider any value use
    > > > of a node with type {None} as dead.
    > > > 
    > > > Bug: chromium:741225
    > > > Change-Id: Icc4b636d1d018c452ba1a2fa7cd3e00e522f1655
    > > > Reviewed-on: https://chromium-review.googlesource.com/641250
    > > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
    > > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
    > > > Cr-Commit-Position: refs/heads/master@{#48208}
    > > 
    > > Bug: chromium:741225
    > > Change-Id: I21316913dae02864f7a6d7c9269405a79f054138
    > > Reviewed-on: https://chromium-review.googlesource.com/692034
    > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
    > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
    > > Cr-Commit-Position: refs/heads/master@{#48232}
    > 
    > Bug: chromium:741225
    > Change-Id: I5702ec34856c075717162153adc765774453c45f
    > Reviewed-on: https://chromium-review.googlesource.com/702264
    > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
    > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#48366}
    
    TBR=jarin@chromium.org,tebbi@chromium.org
    
    Change-Id: Ib0f59b8463681abf6a9158112515aefae3c76b5f
    No-Presubmit: true
    No-Tree-Checks: true
    No-Try: true
    Bug: chromium:741225
    Reviewed-on: https://chromium-review.googlesource.com/707275Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
    Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#48407}
    738e773b
instruction-selector.cc 107 KB