This adds a new ControlFlowOptimizer that - for now - recognizes chains
of Branches generated by the SwitchBuilder for a subset of javascript
switches into Switch nodes. Those Switch nodes are then lowered to
either table or lookup switches.
Also rename Case to IfValue (and introduce IfDefault) for consistency.
BUG=v8:3872
LOG=n
Review URL: https://codereview.chromium.org/931623002
Cr-Commit-Position: refs/heads/master@{#26691}
Up until now we used a special Terminate node to artifically connect non
terminating loops to the End node, but this was kind of adhoc and didn't
work for the CFG. So without all kinds of weird hacks, the end block in
the CFG will not be connected to NTLs, which makes it impossible to
compute post dominance / control dependence in the current setting.
So instead of Terminate, we add a special Branch to NTLs, whose
condition is the special Always node, which corresponds to True, except
that it cannot be folded away. This way we don't need any special
machinery in the scheduler, since it's just a regular Branch.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/875263004
Cr-Commit-Position: refs/heads/master@{#26294}
- Extend verifier to check types of JS and Simplified nodes.
- Untyped nodes now contain NULL as types, enforcing hard failure.
- Typer immediately installs itself as a decorator; remove explicit decorator installation.
- Decorator eagerly types all nodes that have typed inputs
(subsumes typing of constant cache, removing its typing
side-channel and various spurious dependencies on the typer).
- Cut down typer interface to prevent inconsistently typed graphs.
- Remove verification from start, since it caused too much trouble
with semi-wellformed nodes.
- Fix a couple of bugs on the way that got uncovered.
To do: verifying machine operators. Also, various conditions in the
verifier are currently commented out, because they don't yet hold.
BUG=
R=jarin@chromium.org,titzer@chromium.org
Review URL: https://codereview.chromium.org/658543002
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24626 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
