Changeset 242276 in webkit

Timestamp:

Mar 1, 2019, 11:24:08 AM (7 years ago)

Author:

rmorisset@apple.com

Message:

DFG: Loop-invariant code motion (LICM) should not hoist dead code
​https://bugs.webkit.org/show_bug.cgi?id=194945
<rdar://problem/48311657>

Reviewed by Saam Barati.

• dfg/DFGLICMPhase.cpp:

(JSC::DFG::LICMPhase::run):

Location:

trunk

Files:

• JSTests/ChangeLog (modified) (1 diff)
• JSTests/stress/licm-dead-code.js (added)
• Source/JavaScriptCore/ChangeLog (modified) (1 diff)
• Source/JavaScriptCore/dfg/DFGLICMPhase.cpp (modified) (2 diffs)

trunk/JSTests/ChangeLog

@@ -56 +56 @@
         (bar):
         (foo):
+
+2019-02-27  Robin Morisset  <rmorisset@apple.com>
+
+        DFG: Loop-invariant code motion (LICM) should not hoist dead code
+        https://bugs.webkit.org/show_bug.cgi?id=194945
+        <rdar://problem/48311657>
+
+        Reviewed by Mark Lam.
+
+        * stress/licm-dead-code.js: Added.
 
 2019-02-26  Yusuke Suzuki  <ysuzuki@apple.com>

trunk/Source/JavaScriptCore/ChangeLog

@@ -415 +415 @@
         * bytecode/CodeBlock.cpp:
         (JSC::CodeBlock::nameForRegister):
+
+2019-02-27  Robin Morisset  <rmorisset@apple.com>
+
+        DFG: Loop-invariant code motion (LICM) should not hoist dead code
+        https://bugs.webkit.org/show_bug.cgi?id=194945
+        <rdar://problem/48311657>
+
+        Reviewed by Saam Barati.
+
+        * dfg/DFGLICMPhase.cpp:
+        (JSC::DFG::LICMPhase::run):
 
 2019-02-27  Antoine Quint  <graouts@apple.com>

trunk/Source/JavaScriptCore/dfg/DFGLICMPhase.cpp

@@ -185 +185 @@
         bool changed = false;
         for (BasicBlock* block : m_graph.blocksInPreOrder()) {
+            if (!block->cfaHasVisited)
+                continue;
+
             const NaturalLoop* loop = m_graph.m_ssaNaturalLoops->innerMostLoopOf(block);
             if (!loop)
@@ -211 +214 @@
             for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
                 Node*& nodeRef = block->at(nodeIndex);
+                if (nodeRef->op() == ForceOSRExit)
+                    break;
                 for (unsigned stackIndex = loopStack.size(); stackIndex--;)
                     changed |= attemptHoist(block, nodeRef, loopStack[stackIndex]);