Changeset 232334 in webkit for trunk/Source/JavaScriptCore/dfg/DFGCombinedLiveness.cpp

Timestamp:

May 30, 2018, 8:57:59 PM (7 years ago)

Author:

[email protected]

Message:

DFG combined liveness needs to say that the machine CodeBlock's arguments are live
​https://bugs.webkit.org/show_bug.cgi?id=186121
<rdar://problem/39377796>

Reviewed by Keith Miller.

JSTests:

• stress/combined-liveness-needs-to-say-arguments-are-live.js: Added.

(baz):
(foo):

Source/JavaScriptCore:

DFG's combined liveness was reporting that the machine CodeBlock's |this|
argument was dead at certain points in the program. However, a CodeBlock's
arguments are considered live for the entire function. This fixes a bug
where object allocation sinking phase skipped materializing an allocation
because it thought that the argument it was associated with, |this|, was dead.

• dfg/DFGCombinedLiveness.cpp:

(JSC::DFG::liveNodesAtHead):

File:

• trunk/Source/JavaScriptCore/dfg/DFGCombinedLiveness.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/dfg/DFGCombinedLiveness.cpp

@@ -1 +1 @@
 /*
- * Copyright (C) 2015-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2018 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -45 +45 @@
     
     AvailabilityMap& availabilityMap = block->ssa->availabilityAtHead;
-    graph.forAllLocalsLiveInBytecode(
+    graph.forAllLiveInBytecode(
         block->at(0)->origin.forExit,
         [&] (VirtualRegister reg) {