<!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>[280234] releases/WebKitGTK/webkit-2.32</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/280234">280234</a></dd>
<dt>Author</dt> <dd>aperez@igalia.com</dd>
<dt>Date</dt> <dd>2021-07-23 02:03:51 -0700 (Fri, 23 Jul 2021)</dd>
</dl>

<h3>Log Message</h3>
<pre>Merge <a href="http://trac.webkit.org/projects/webkit/changeset/278578">r278578</a> - Short circuit read modify write nodes emit byte code that uses the wrong locals
https://bugs.webkit.org/show_bug.cgi?id=226576
<rdar://problem/78810362>

Reviewed by Yusuke Suzuki.

JSTests:

* stress/short-circuit-read-modify-should-use-the-write-virtual-registers.js: Added.
(eval):

Source/JavaScriptCore:

It's never a good idea to use the wrong local :-)

This patch also adds support for dumping predecessors of basic blocks
in the bytecode dump.

* bytecode/BytecodeDumper.cpp:
(JSC::CodeBlockBytecodeDumper<Block>::dumpGraph):
* bytecompiler/NodesCodegen.cpp:
(JSC::ShortCircuitReadModifyResolveNode::emitBytecode):
(JSC::ShortCircuitReadModifyDotNode::emitBytecode):
(JSC::ShortCircuitReadModifyBracketNode::emitBytecode):</pre>

<h3>Modified Paths</h3>
<ul>
<li><a href="#releasesWebKitGTKwebkit232JSTestsChangeLog">releases/WebKitGTK/webkit-2.32/JSTests/ChangeLog</a></li>
<li><a href="#releasesWebKitGTKwebkit232SourceJavaScriptCoreChangeLog">releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/ChangeLog</a></li>
<li><a href="#releasesWebKitGTKwebkit232SourceJavaScriptCorebytecodeBytecodeDumpercpp">releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecode/BytecodeDumper.cpp</a></li>
<li><a href="#releasesWebKitGTKwebkit232SourceJavaScriptCorebytecompilerNodesCodegencpp">releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp</a></li>
</ul>

<h3>Added Paths</h3>
<ul>
<li><a href="#releasesWebKitGTKwebkit232JSTestsstressshortcircuitreadmodifyshouldusethewritevirtualregistersjs">releases/WebKitGTK/webkit-2.32/JSTests/stress/short-circuit-read-modify-should-use-the-write-virtual-registers.js</a></li>
</ul>

</div>
<div id="patch">
<h3>Diff</h3>
<a id="releasesWebKitGTKwebkit232JSTestsChangeLog"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.32/JSTests/ChangeLog (280233 => 280234)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.32/JSTests/ChangeLog 2021-07-23 09:00:00 UTC (rev 280233)
+++ releases/WebKitGTK/webkit-2.32/JSTests/ChangeLog    2021-07-23 09:03:51 UTC (rev 280234)
</span><span class="lines">@@ -1,3 +1,14 @@
</span><ins>+2021-06-07  Saam Barati  <sbarati@apple.com>
+
+        Short circuit read modify write nodes emit byte code that uses the wrong locals
+        https://bugs.webkit.org/show_bug.cgi?id=226576
+        <rdar://problem/78810362>
+
+        Reviewed by Yusuke Suzuki.
+
+        * stress/short-circuit-read-modify-should-use-the-write-virtual-registers.js: Added.
+        (eval):
+
</ins><span class="cx"> 2021-02-25  Yusuke Suzuki  <ysuzuki@apple.com>
</span><span class="cx"> 
</span><span class="cx">         [JSC] Fix typo in wasm error message
</span></span></pre></div>
<a id="releasesWebKitGTKwebkit232JSTestsstressshortcircuitreadmodifyshouldusethewritevirtualregistersjs"></a>
<div class="addfile"><h4>Added: releases/WebKitGTK/webkit-2.32/JSTests/stress/short-circuit-read-modify-should-use-the-write-virtual-registers.js (0 => 280234)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.32/JSTests/stress/short-circuit-read-modify-should-use-the-write-virtual-registers.js                                (rev 0)
+++ releases/WebKitGTK/webkit-2.32/JSTests/stress/short-circuit-read-modify-should-use-the-write-virtual-registers.js   2021-07-23 09:03:51 UTC (rev 280234)
</span><span class="lines">@@ -0,0 +1,33 @@
</span><ins>+eval(`
+    for (var i=0; i < 1000; i++) {
+        const x = 1;
+        let y = 42;
+        try {
+            y ||= x *= some;
+        }
+        catch { }
+        finally { }
+    }
+`);
+
+eval(`
+    for (var i=0; i < 1000; i++) {
+        const x = 1;
+        try {
+            foo.x ||= x *= some;
+        }
+        catch { }
+        finally { }
+    }
+`);
+
+eval(`
+    for(var i = 0; i < 1000; i++) {
+        const x = 1;
+        try {
+            foo[0] ||= x *= some;
+        }
+        catch { }
+        finally { }
+    }
+`);
</ins></span></pre></div>
<a id="releasesWebKitGTKwebkit232SourceJavaScriptCoreChangeLog"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/ChangeLog (280233 => 280234)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/ChangeLog   2021-07-23 09:00:00 UTC (rev 280233)
+++ releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/ChangeLog      2021-07-23 09:03:51 UTC (rev 280234)
</span><span class="lines">@@ -1,3 +1,23 @@
</span><ins>+2021-06-07  Saam Barati  <sbarati@apple.com>
+
+        Short circuit read modify write nodes emit byte code that uses the wrong locals
+        https://bugs.webkit.org/show_bug.cgi?id=226576
+        <rdar://problem/78810362>
+
+        Reviewed by Yusuke Suzuki.
+
+        It's never a good idea to use the wrong local :-)
+        
+        This patch also adds support for dumping predecessors of basic blocks
+        in the bytecode dump.
+
+        * bytecode/BytecodeDumper.cpp:
+        (JSC::CodeBlockBytecodeDumper<Block>::dumpGraph):
+        * bytecompiler/NodesCodegen.cpp:
+        (JSC::ShortCircuitReadModifyResolveNode::emitBytecode):
+        (JSC::ShortCircuitReadModifyDotNode::emitBytecode):
+        (JSC::ShortCircuitReadModifyBracketNode::emitBytecode):
+
</ins><span class="cx"> 2021-04-26  Keith Miller  <keith_miller@apple.com>
</span><span class="cx"> 
</span><span class="cx">         numCalleeLocals, numParameters, and numVars should be unsigned
</span></span></pre></div>
<a id="releasesWebKitGTKwebkit232SourceJavaScriptCorebytecodeBytecodeDumpercpp"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecode/BytecodeDumper.cpp (280233 => 280234)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecode/BytecodeDumper.cpp 2021-07-23 09:00:00 UTC (rev 280233)
+++ releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecode/BytecodeDumper.cpp    2021-07-23 09:03:51 UTC (rev 280234)
</span><span class="lines">@@ -277,6 +277,17 @@
</span><span class="cx"> 
</span><span class="cx">     out.printf("\n");
</span><span class="cx"> 
</span><ins>+    Vector<Vector<unsigned>> predecessors;
+    predecessors.resize(graph.size());
+    for (auto& block : graph) {
+        if (block.isEntryBlock() || block.isExitBlock())
+            continue;
+        for (auto successorIndex : block.successors()) {
+            if (!predecessors[successorIndex].contains(block.index()))
+                predecessors[successorIndex].append(block.index());
+        }
+    }
+
</ins><span class="cx">     for (BytecodeBasicBlock& block : graph) {
</span><span class="cx">         if (block.isEntryBlock() || block.isExitBlock())
</span><span class="cx">             continue;
</span><span class="lines">@@ -283,6 +294,13 @@
</span><span class="cx"> 
</span><span class="cx">         out.print("bb#", block.index(), "\n");
</span><span class="cx"> 
</span><ins>+        out.print("Predecessors: [");
+        for (unsigned predecessor : predecessors[block.index()]) {
+            if (!graph[predecessor].isEntryBlock())
+                out.print(" #", predecessor);
+        }
+        out.print(" ]\n");
+
</ins><span class="cx">         for (unsigned i = 0; i < block.totalLength(); ) {
</span><span class="cx">             auto& currentInstruction = instructions.at(i + block.leaderOffset());
</span><span class="cx">             dumper.dumpBytecode(currentInstruction, icStatusMap);
</span></span></pre></div>
<a id="releasesWebKitGTKwebkit232SourceJavaScriptCorebytecompilerNodesCodegencpp"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp (280233 => 280234)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp       2021-07-23 09:00:00 UTC (rev 280233)
+++ releases/WebKitGTK/webkit-2.32/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp  2021-07-23 09:03:51 UTC (rev 280234)
</span><span class="lines">@@ -3469,7 +3469,7 @@
</span><span class="cx">             Ref<Label> afterAssignment = generator.newLabel();
</span><span class="cx">             emitShortCircuitAssignment(generator, result.get(), m_operator, afterAssignment.get());
</span><span class="cx"> 
</span><del>-            result = generator.emitNode(result.get(), m_right); // Execute side effects first.
</del><ins>+            generator.emitNode(result.get(), m_right); // Execute side effects first.
</ins><span class="cx">             bool threwException = generator.emitReadOnlyExceptionIfNeeded(var);
</span><span class="cx"> 
</span><span class="cx">             if (!threwException)
</span><span class="lines">@@ -3486,7 +3486,7 @@
</span><span class="cx">             Ref<Label> afterAssignment = generator.newLabel();
</span><span class="cx">             emitShortCircuitAssignment(generator, result.get(), m_operator, afterAssignment.get());
</span><span class="cx"> 
</span><del>-            result = generator.emitNode(result.get(), m_right);
</del><ins>+            generator.emitNode(result.get(), m_right);
</ins><span class="cx">             generator.move(local.get(), result.get());
</span><span class="cx">             generator.emitProfileType(result.get(), var, divotStart(), divotEnd());
</span><span class="cx"> 
</span><span class="lines">@@ -3499,7 +3499,7 @@
</span><span class="cx">         Ref<Label> afterAssignment = generator.newLabel();
</span><span class="cx">         emitShortCircuitAssignment(generator, result.get(), m_operator, afterAssignment.get());
</span><span class="cx"> 
</span><del>-        result = generator.emitNode(result.get(), m_right);
</del><ins>+        generator.emitNode(result.get(), m_right);
</ins><span class="cx">         generator.emitProfileType(result.get(), var, divotStart(), divotEnd());
</span><span class="cx"> 
</span><span class="cx">         generator.emitLabel(afterAssignment.get());
</span><span class="lines">@@ -3509,7 +3509,9 @@
</span><span class="cx">     generator.emitExpressionInfo(newDivot, divotStart(), newDivot);
</span><span class="cx">     RefPtr<RegisterID> scope = generator.emitResolveScope(nullptr, var);
</span><span class="cx"> 
</span><del>-    RefPtr<RegisterID> result = generator.emitGetFromScope(generator.tempDestination(dst), scope.get(), var, ThrowIfNotFound);
</del><ins>+    RefPtr<RegisterID> result = generator.tempDestination(dst);
+
+    generator.emitGetFromScope(result.get(), scope.get(), var, ThrowIfNotFound);
</ins><span class="cx">     generator.emitTDZCheckIfNecessary(var, result.get(), nullptr);
</span><span class="cx"> 
</span><span class="cx">     Ref<Label> afterAssignment = generator.newLabel();
</span><span class="lines">@@ -3642,24 +3644,24 @@
</span><span class="cx">     RefPtr<RegisterID> base = generator.emitNodeForLeftHandSide(m_base, m_rightHasAssignments, m_right->isPure(generator));
</span><span class="cx">     RefPtr<RegisterID> thisValue;
</span><span class="cx"> 
</span><del>-    RefPtr<RegisterID> result;
</del><ins>+    RefPtr<RegisterID> result = generator.tempDestination(dst);
</ins><span class="cx"> 
</span><span class="cx">     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
</span><span class="cx">     if (m_base->isSuperNode()) {
</span><span class="cx">         thisValue = generator.ensureThis();
</span><del>-        result = generator.emitGetById(generator.tempDestination(dst), base.get(), thisValue.get(), m_ident);
</del><ins>+        generator.emitGetById(result.get(), base.get(), thisValue.get(), m_ident);
</ins><span class="cx">     } else
</span><del>-        result = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
</del><ins>+        generator.emitGetById(result.get(), base.get(), m_ident);
</ins><span class="cx"> 
</span><span class="cx">     Ref<Label> afterAssignment = generator.newLabel();
</span><span class="cx">     emitShortCircuitAssignment(generator, result.get(), m_operator, afterAssignment.get());
</span><span class="cx"> 
</span><del>-    result = generator.emitNode(result.get(), m_right);
</del><ins>+    generator.emitNode(result.get(), m_right);
</ins><span class="cx">     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
</span><span class="cx">     if (m_base->isSuperNode())
</span><del>-        result = generator.emitPutById(base.get(), thisValue.get(), m_ident, result.get());
</del><ins>+        generator.emitPutById(base.get(), thisValue.get(), m_ident, result.get());
</ins><span class="cx">     else
</span><del>-        result = generator.emitPutById(base.get(), m_ident, result.get());
</del><ins>+        generator.emitPutById(base.get(), m_ident, result.get());
</ins><span class="cx">     generator.emitProfileType(result.get(), divotStart(), divotEnd());
</span><span class="cx"> 
</span><span class="cx">     generator.emitLabel(afterAssignment.get());
</span><span class="lines">@@ -3738,24 +3740,24 @@
</span><span class="cx">     RefPtr<RegisterID> property = generator.emitNodeForLeftHandSideForProperty(m_subscript, m_rightHasAssignments, m_right->isPure(generator));
</span><span class="cx">     RefPtr<RegisterID> thisValue;
</span><span class="cx"> 
</span><del>-    RefPtr<RegisterID> result;
</del><ins>+    RefPtr<RegisterID> result = generator.tempDestination(dst);
</ins><span class="cx"> 
</span><span class="cx">     generator.emitExpressionInfo(subexpressionDivot(), subexpressionStart(), subexpressionEnd());
</span><span class="cx">     if (m_base->isSuperNode()) {
</span><span class="cx">         thisValue = generator.ensureThis();
</span><del>-        result = generator.emitGetByVal(generator.tempDestination(dst), base.get(), thisValue.get(), property.get());
</del><ins>+        generator.emitGetByVal(result.get(), base.get(), thisValue.get(), property.get());
</ins><span class="cx">     } else
</span><del>-        result = generator.emitGetByVal(generator.tempDestination(dst), base.get(), property.get());
</del><ins>+        generator.emitGetByVal(result.get(), base.get(), property.get());
</ins><span class="cx"> 
</span><span class="cx">     Ref<Label> afterAssignment = generator.newLabel();
</span><span class="cx">     emitShortCircuitAssignment(generator, result.get(), m_operator, afterAssignment.get());
</span><span class="cx"> 
</span><del>-    result = generator.emitNode(result.get(), m_right);
</del><ins>+    generator.emitNode(result.get(), m_right);
</ins><span class="cx">     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
</span><span class="cx">     if (m_base->isSuperNode())
</span><del>-        result = generator.emitPutByVal(base.get(), thisValue.get(), property.get(), result.get());
</del><ins>+        generator.emitPutByVal(base.get(), thisValue.get(), property.get(), result.get());
</ins><span class="cx">     else
</span><del>-        result = generator.emitPutByVal(base.get(), property.get(), result.get());
</del><ins>+        generator.emitPutByVal(base.get(), property.get(), result.get());
</ins><span class="cx">     generator.emitProfileType(result.get(), divotStart(), divotEnd());
</span><span class="cx"> 
</span><span class="cx">     generator.emitLabel(afterAssignment.get());
</span></span></pre>
</div>
</div>

</body>
</html>