<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[191718] trunk/Source/JavaScriptCore</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/191718">191718</a></dd>
<dt>Author</dt> <dd>fpizlo@apple.com</dd>
<dt>Date</dt> <dd>2015-10-28 18:57:17 -0700 (Wed, 28 Oct 2015)</dd>
</dl>
<h3>Log Message</h3>
<pre>B3::reduceStrength() should do DCE
https://bugs.webkit.org/show_bug.cgi?id=150656
Reviewed by Saam Barati.
* b3/B3BasicBlock.cpp:
(JSC::B3::BasicBlock::removeNops): This now deletes the values from the procedure, to preserve the invariant that valuesInProc == valuesInBlocks.
* b3/B3BasicBlock.h:
* b3/B3Procedure.cpp:
(JSC::B3::Procedure::deleteValue): Add a utility used by removeNops().
(JSC::B3::Procedure::addValueIndex): Make sure that we reuse Value indices so that m_values doesn't get too sparse.
* b3/B3Procedure.h:
(JSC::B3::Procedure::ValuesCollection::iterator::iterator): Teach this that m_values can be slightly sparse.
(JSC::B3::Procedure::ValuesCollection::iterator::operator++):
(JSC::B3::Procedure::ValuesCollection::iterator::operator!=):
(JSC::B3::Procedure::ValuesCollection::iterator::findNext):
(JSC::B3::Procedure::values):
* b3/B3ProcedureInlines.h:
(JSC::B3::Procedure::add): Use addValueIndex() instead of always creating a new index.
* b3/B3ReduceStrength.cpp: Implement the optimization using UseCounts and Effects.</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceJavaScriptCoreChangeLog">trunk/Source/JavaScriptCore/ChangeLog</a></li>
<li><a href="#trunkSourceJavaScriptCoreb3B3BasicBlockcpp">trunk/Source/JavaScriptCore/b3/B3BasicBlock.cpp</a></li>
<li><a href="#trunkSourceJavaScriptCoreb3B3BasicBlockh">trunk/Source/JavaScriptCore/b3/B3BasicBlock.h</a></li>
<li><a href="#trunkSourceJavaScriptCoreb3B3Procedurecpp">trunk/Source/JavaScriptCore/b3/B3Procedure.cpp</a></li>
<li><a href="#trunkSourceJavaScriptCoreb3B3Procedureh">trunk/Source/JavaScriptCore/b3/B3Procedure.h</a></li>
<li><a href="#trunkSourceJavaScriptCoreb3B3ProcedureInlinesh">trunk/Source/JavaScriptCore/b3/B3ProcedureInlines.h</a></li>
<li><a href="#trunkSourceJavaScriptCoreb3B3ReduceStrengthcpp">trunk/Source/JavaScriptCore/b3/B3ReduceStrength.cpp</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceJavaScriptCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/ChangeLog (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/ChangeLog        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/ChangeLog        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -1,3 +1,26 @@
</span><ins>+2015-10-28 Filip Pizlo <fpizlo@apple.com>
+
+ B3::reduceStrength() should do DCE
+ https://bugs.webkit.org/show_bug.cgi?id=150656
+
+ Reviewed by Saam Barati.
+
+ * b3/B3BasicBlock.cpp:
+ (JSC::B3::BasicBlock::removeNops): This now deletes the values from the procedure, to preserve the invariant that valuesInProc == valuesInBlocks.
+ * b3/B3BasicBlock.h:
+ * b3/B3Procedure.cpp:
+ (JSC::B3::Procedure::deleteValue): Add a utility used by removeNops().
+ (JSC::B3::Procedure::addValueIndex): Make sure that we reuse Value indices so that m_values doesn't get too sparse.
+ * b3/B3Procedure.h:
+ (JSC::B3::Procedure::ValuesCollection::iterator::iterator): Teach this that m_values can be slightly sparse.
+ (JSC::B3::Procedure::ValuesCollection::iterator::operator++):
+ (JSC::B3::Procedure::ValuesCollection::iterator::operator!=):
+ (JSC::B3::Procedure::ValuesCollection::iterator::findNext):
+ (JSC::B3::Procedure::values):
+ * b3/B3ProcedureInlines.h:
+ (JSC::B3::Procedure::add): Use addValueIndex() instead of always creating a new index.
+ * b3/B3ReduceStrength.cpp: Implement the optimization using UseCounts and Effects.
+
</ins><span class="cx"> 2015-10-28 Joseph Pecoraro <pecoraro@apple.com>
</span><span class="cx">
</span><span class="cx"> Web Inspector: Remove unused / duplicate WebSocket timeline records
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreb3B3BasicBlockcpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/b3/B3BasicBlock.cpp (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/b3/B3BasicBlock.cpp        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/b3/B3BasicBlock.cpp        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -29,6 +29,7 @@
</span><span class="cx"> #if ENABLE(B3_JIT)
</span><span class="cx">
</span><span class="cx"> #include "B3BasicBlockUtils.h"
</span><ins>+#include "B3Procedure.h"
</ins><span class="cx"> #include "B3Value.h"
</span><span class="cx"> #include <wtf/ListDump.h>
</span><span class="cx">
</span><span class="lines">@@ -66,13 +67,15 @@
</span><span class="cx"> return B3::replacePredecessor(this, from, to);
</span><span class="cx"> }
</span><span class="cx">
</span><del>-void BasicBlock::removeNops()
</del><ins>+void BasicBlock::removeNops(Procedure& procedure)
</ins><span class="cx"> {
</span><span class="cx"> unsigned sourceIndex = 0;
</span><span class="cx"> unsigned targetIndex = 0;
</span><span class="cx"> while (sourceIndex < size()) {
</span><span class="cx"> Value* value = m_values[sourceIndex++];
</span><del>- if (value->opcode() != Nop)
</del><ins>+ if (value->opcode() == Nop)
+ procedure.deleteValue(value);
+ else
</ins><span class="cx"> m_values[targetIndex++] = value;
</span><span class="cx"> }
</span><span class="cx"> m_values.resize(targetIndex);
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreb3B3BasicBlockh"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/b3/B3BasicBlock.h (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/b3/B3BasicBlock.h        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/b3/B3BasicBlock.h        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -95,7 +95,7 @@
</span><span class="cx">
</span><span class="cx"> double frequency() const { return m_frequency; }
</span><span class="cx">
</span><del>- void removeNops();
</del><ins>+ void removeNops(Procedure&);
</ins><span class="cx">
</span><span class="cx"> void dump(PrintStream&) const;
</span><span class="cx"> void deepDump(PrintStream&) const;
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreb3B3Procedurecpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/b3/B3Procedure.cpp (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/b3/B3Procedure.cpp        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/b3/B3Procedure.cpp        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -73,6 +73,24 @@
</span><span class="cx"> return B3::blocksInPostOrder(at(0));
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+void Procedure::deleteValue(Value* value)
+{
+ ASSERT(m_values[value->index()].get() == value);
+ m_valueIndexFreeList.append(value->index());
+ m_values[value->index()] = nullptr;
+}
+
+size_t Procedure::addValueIndex()
+{
+ if (m_valueIndexFreeList.isEmpty()) {
+ size_t index = m_values.size();
+ m_values.append(nullptr);
+ return index;
+ }
+
+ return m_valueIndexFreeList.takeLast();
+}
+
</ins><span class="cx"> } } // namespace JSC::B3
</span><span class="cx">
</span><span class="cx"> #endif // ENABLE(B3_JIT)
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreb3B3Procedureh"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/b3/B3Procedure.h (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/b3/B3Procedure.h        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/b3/B3Procedure.h        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -132,7 +132,7 @@
</span><span class="cx">
</span><span class="cx"> iterator(const Procedure& procedure, unsigned index)
</span><span class="cx"> : m_procedure(&procedure)
</span><del>- , m_index(index)
</del><ins>+ , m_index(findNext(index))
</ins><span class="cx"> {
</span><span class="cx"> }
</span><span class="cx">
</span><span class="lines">@@ -143,7 +143,7 @@
</span><span class="cx">
</span><span class="cx"> iterator& operator++()
</span><span class="cx"> {
</span><del>- m_index++;
</del><ins>+ m_index = findNext(m_index + 1);
</ins><span class="cx"> return *this;
</span><span class="cx"> }
</span><span class="cx">
</span><span class="lines">@@ -159,6 +159,12 @@
</span><span class="cx"> }
</span><span class="cx">
</span><span class="cx"> private:
</span><ins>+ unsigned findNext(unsigned index)
+ {
+ while (index < m_procedure->m_values.size() && !m_procedure->m_values[index])
+ index++;
+ return index;
+ }
</ins><span class="cx">
</span><span class="cx"> const Procedure* m_procedure;
</span><span class="cx"> unsigned m_index;
</span><span class="lines">@@ -177,6 +183,8 @@
</span><span class="cx">
</span><span class="cx"> ValuesCollection values() const { return ValuesCollection(*this); }
</span><span class="cx">
</span><ins>+ void deleteValue(Value*);
+
</ins><span class="cx"> // The name has to be a string literal, since we don't do any memory management for the string.
</span><span class="cx"> void setLastPhaseName(const char* name)
</span><span class="cx"> {
</span><span class="lines">@@ -186,8 +194,11 @@
</span><span class="cx"> const char* lastPhaseName() const { return m_lastPhaseName; }
</span><span class="cx">
</span><span class="cx"> private:
</span><ins>+ JS_EXPORT_PRIVATE size_t addValueIndex();
+
</ins><span class="cx"> Vector<std::unique_ptr<BasicBlock>> m_blocks;
</span><span class="cx"> Vector<std::unique_ptr<Value>> m_values;
</span><ins>+ Vector<size_t> m_valueIndexFreeList;
</ins><span class="cx"> const char* m_lastPhaseName;
</span><span class="cx"> };
</span><span class="cx">
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreb3B3ProcedureInlinesh"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/b3/B3ProcedureInlines.h (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/b3/B3ProcedureInlines.h        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/b3/B3ProcedureInlines.h        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -36,9 +36,10 @@
</span><span class="cx"> template<typename ValueType, typename... Arguments>
</span><span class="cx"> ValueType* Procedure::add(Arguments... arguments)
</span><span class="cx"> {
</span><del>- std::unique_ptr<ValueType> value(new ValueType(m_values.size(), arguments...));
</del><ins>+ size_t index = addValueIndex();
+ std::unique_ptr<ValueType> value(new ValueType(index, arguments...));
</ins><span class="cx"> ValueType* result = value.get();
</span><del>- m_values.append(WTF::move(value));
</del><ins>+ m_values[index] = WTF::move(value);
</ins><span class="cx"> return result;
</span><span class="cx"> }
</span><span class="cx">
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreb3B3ReduceStrengthcpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/b3/B3ReduceStrength.cpp (191717 => 191718)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/b3/B3ReduceStrength.cpp        2015-10-29 01:30:16 UTC (rev 191717)
+++ trunk/Source/JavaScriptCore/b3/B3ReduceStrength.cpp        2015-10-29 01:57:17 UTC (rev 191718)
</span><span class="lines">@@ -32,6 +32,7 @@
</span><span class="cx"> #include "B3MemoryValue.h"
</span><span class="cx"> #include "B3PhaseScope.h"
</span><span class="cx"> #include "B3ProcedureInlines.h"
</span><ins>+#include "B3UseCounts.h"
</ins><span class="cx"> #include "B3ValueInlines.h"
</span><span class="cx">
</span><span class="cx"> namespace JSC { namespace B3 {
</span><span class="lines">@@ -59,9 +60,16 @@
</span><span class="cx"> process();
</span><span class="cx"> m_insertionSet.execute(m_block);
</span><span class="cx">
</span><del>- // FIXME: This should also do DCE.
- block->removeNops();
</del><ins>+ block->removeNops(m_proc);
</ins><span class="cx"> }
</span><ins>+
+ UseCounts useCounts(m_proc);
+ for (Value* value : m_proc.values()) {
+ if (!useCounts[value] && !value->effects().mustExecute()) {
+ value->replaceWithNop();
+ m_changed = true;
+ }
+ }
</ins><span class="cx">
</span><span class="cx"> result |= m_changed;
</span><span class="cx"> } while (m_changed);
</span></span></pre>
</div>
</div>
</body>
</html>