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<base href="https://bugs.webkit.org/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - ObjectAllocationSinkingPhase::insertOSRHintsForUpdate() fails to emit updated hints in some cases"
href="https://bugs.webkit.org/show_bug.cgi?id=161492">161492</a>
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<th>Summary</th>
<td>ObjectAllocationSinkingPhase::insertOSRHintsForUpdate() fails to emit updated hints in some cases
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr>
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<th>Product</th>
<td>WebKit
</td>
</tr>
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<th>Version</th>
<td>WebKit Nightly Build
</td>
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<th>Hardware</th>
<td>All
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>Normal
</td>
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<th>Priority</th>
<td>P2
</td>
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<th>Component</th>
<td>JavaScriptCore
</td>
</tr>
<tr>
<th>Assignee</th>
<td>webkit-unassigned@lists.webkit.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>fpizlo@apple.com
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<p>
<div>
<pre>This seems to cause trouble:
a: CreateActivation()
MovHint(@a, loc1)
b: NewFunction(@a)
MovHint(@b, loc2)
c: NewFunction(@b)
MovHint(@c, loc3)
Escape(@b)
I'm seeing code like this:
a: PhantomCreateActivation()
MovHint(@a, loc1)
b: PhantomNewFunction(@a)
PutHint(@b, @a, scope)
MovHint(@b, loc2)
c: PhantomNewFunction(@b)
PutHint(@c, @a, scope)
MovHint(@c, loc3)
d: MaterializeCreateActivation()
e: NewFunction(@d)
MovHint(@d, loc1)
MovHint(@e, loc2)
Escape(@e)
But this is wrong, because if we exit, then we will recreate @c pointing at a newly materialized activation, rather than at @d. In other words, the phase should have produced this code instead:
a: PhantomCreateActivation()
MovHint(@a, loc1)
b: PhantomNewFunction(@a)
PutHint(@b, @a, scope)
MovHint(@b, loc2)
c: PhantomNewFunction(@b)
PutHint(@c, @a, scope)
MovHint(@c, loc3)
d: MaterializeCreateActivation()
e: NewFunction(@d)
PutHint(@c, @e, scope) <---- THIS
MovHint(@d, loc1)
MovHint(@e, loc2)
Escape(@e)
The phase seems to have code to do this. I'm still investigating what goes wrong.</pre>
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</p>
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