Title: [189531] trunk/Source/_javascript_Core
- Revision
- 189531
- Author
- benja...@webkit.org
- Date
- 2015-09-08 21:02:24 -0700 (Tue, 08 Sep 2015)
Log Message
[JSC] reduce the amount of memory access needed for LivenessAnalysisPhase
https://bugs.webkit.org/show_bug.cgi?id=148414
Patch by Benjamin Poulain <bpoul...@apple.com> on 2015-09-08
Reviewed by Mark Lam.
LivenessAnalysisPhase still causes a huge number of cache miss.
This patch reduces the amount of accesses needed by the HashTables.
* dfg/DFGBasicBlock.h:
* dfg/DFGLivenessAnalysisPhase.cpp:
(JSC::DFG::LivenessAnalysisPhase::run):
(JSC::DFG::LivenessAnalysisPhase::process):
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (189530 => 189531)
--- trunk/Source/_javascript_Core/ChangeLog 2015-09-09 03:27:48 UTC (rev 189530)
+++ trunk/Source/_javascript_Core/ChangeLog 2015-09-09 04:02:24 UTC (rev 189531)
@@ -1,3 +1,18 @@
+2015-09-08 Benjamin Poulain <bpoul...@apple.com>
+
+ [JSC] reduce the amount of memory access needed for LivenessAnalysisPhase
+ https://bugs.webkit.org/show_bug.cgi?id=148414
+
+ Reviewed by Mark Lam.
+
+ LivenessAnalysisPhase still causes a huge number of cache miss.
+ This patch reduces the amount of accesses needed by the HashTables.
+
+ * dfg/DFGBasicBlock.h:
+ * dfg/DFGLivenessAnalysisPhase.cpp:
+ (JSC::DFG::LivenessAnalysisPhase::run):
+ (JSC::DFG::LivenessAnalysisPhase::process):
+
2015-09-08 Myles C. Maxfield <mmaxfi...@apple.com>
Prospective build fix after r189517
Modified: trunk/Source/_javascript_Core/dfg/DFGBasicBlock.h (189530 => 189531)
--- trunk/Source/_javascript_Core/dfg/DFGBasicBlock.h 2015-09-09 03:27:48 UTC (rev 189530)
+++ trunk/Source/_javascript_Core/dfg/DFGBasicBlock.h 2015-09-09 04:02:24 UTC (rev 189531)
@@ -239,8 +239,9 @@
AvailabilityMap availabilityAtHead;
AvailabilityMap availabilityAtTail;
+ bool liveAtTailIsDirty { false };
+ HashSet<Node*> liveAtTail;
HashSet<Node*> liveAtHead;
- HashSet<Node*> liveAtTail;
HashMap<Node*, AbstractValue> valuesAtHead;
HashMap<Node*, AbstractValue> valuesAtTail;
Modified: trunk/Source/_javascript_Core/dfg/DFGLivenessAnalysisPhase.cpp (189530 => 189531)
--- trunk/Source/_javascript_Core/dfg/DFGLivenessAnalysisPhase.cpp 2015-09-09 03:27:48 UTC (rev 189530)
+++ trunk/Source/_javascript_Core/dfg/DFGLivenessAnalysisPhase.cpp 2015-09-09 04:02:24 UTC (rev 189531)
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -57,6 +57,7 @@
BasicBlock* block = m_graph.block(blockIndex);
if (!block)
continue;
+ block->ssa->liveAtTailIsDirty = true;
block->ssa->liveAtHead.clear();
block->ssa->liveAtTail.clear();
}
@@ -85,8 +86,11 @@
if (!block)
return;
+ if (!block->ssa->liveAtTailIsDirty)
+ return;
+ block->ssa->liveAtTailIsDirty = false;
+
m_live = block->ssa->liveAtTail;
-
for (unsigned nodeIndex = block->size(); nodeIndex--;) {
Node* node = block->at(nodeIndex);
@@ -128,12 +132,16 @@
}
}
- if (m_live == block->ssa->liveAtHead)
- return;
-
- m_changed = true;
- for (unsigned i = block->predecessors.size(); i--;)
- block->predecessors[i]->ssa->liveAtTail.add(m_live.begin(), m_live.end());
+ for (Node* node : m_live) {
+ if (!block->ssa->liveAtHead.contains(node)) {
+ m_changed = true;
+ for (unsigned i = block->predecessors.size(); i--;) {
+ BasicBlock* predecessor = block->predecessors[i];
+ if (predecessor->ssa->liveAtTail.add(node).isNewEntry)
+ predecessor->ssa->liveAtTailIsDirty = true;
+ }
+ }
+ }
block->ssa->liveAtHead = WTF::move(m_live);
}
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