Changeset 281029 in webkit

Timestamp:

Aug 13, 2021, 12:29:04 PM (5 years ago)

Author:

keith_miller@apple.com

Message:

EnumeratorNextUpdatePropertyName always needs to be able to handle IndexedMode
​https://bugs.webkit.org/show_bug.cgi?id=229087

Reviewed by Filip Pizlo.

JSTests:

• stress/for-in-own-structure-and-generic-with-late-add-indexed.js: Added.

(test):
(Foo):

Source/JavaScriptCore:

Right now, this operation incorrectly assumes that EnumeratorNextUpdateIndexAndMode will guarantee
the mode matches the seen mode set. But no speculation is guaranteed and adding such a guarantee
would require adding checkpoints, which is likely not worth it. Instead, this patch just makes
sure we always handle the allocation for IndexedMode.

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileEnumeratorNextUpdatePropertyName):

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::compileCompareStrictEq):

Location:

trunk

Files:

• JSTests/ChangeLog (modified) (1 diff)
• JSTests/stress/for-in-own-structure-and-generic-with-late-add-indexed.js (added)
• Source/JavaScriptCore/ChangeLog (modified) (1 diff)
• Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp (modified) (2 diffs)
• Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp (modified) (2 diffs)

trunk/JSTests/ChangeLog

@@ +1 @@
+2021-08-13  Keith Miller  <keith_miller@apple.com>
+
+        EnumeratorNextUpdatePropertyName always needs to be able to handle IndexedMode
+        https://bugs.webkit.org/show_bug.cgi?id=229087
+
+        Reviewed by Filip Pizlo.
+
+        * stress/for-in-own-structure-and-generic-with-late-add-indexed.js: Added.
+        (test):
+        (Foo):
+
 2021-08-11  Yusuke Suzuki  <ysuzuki@apple.com>
 

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2021-08-13  Keith Miller  <keith_miller@apple.com>
+
+        EnumeratorNextUpdatePropertyName always needs to be able to handle IndexedMode
+        https://bugs.webkit.org/show_bug.cgi?id=229087
+
+        Reviewed by Filip Pizlo.
+
+        Right now, this operation incorrectly assumes that EnumeratorNextUpdateIndexAndMode will guarantee
+        the mode matches the seen mode set. But no speculation is guaranteed and adding such a guarantee
+        would require adding checkpoints, which is likely not worth it. Instead, this patch just makes
+        sure we always handle the allocation for IndexedMode.
+
+        * dfg/DFGSpeculativeJIT.cpp:
+        (JSC::DFG::SpeculativeJIT::compileEnumeratorNextUpdatePropertyName):
+        * ftl/FTLLowerDFGToB3.cpp:
+        (JSC::FTL::DFG::LowerDFGToB3::compileCompareStrictEq):
+
 2021-08-12  Mark Lam  <mark.lam@apple.com>
 

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp

@@ -13592 +13592 @@
     MacroAssembler::Jump operationCall;
 
-    bool needsOperation = seenModes.contains(JSPropertyNameEnumerator::IndexedMode);
-
-    // Make sure we flush on all code paths if we could call the operation.
-    if (needsOperation)
-        flushRegisters();
+    // Make sure we flush on all code paths if we will call the operation.
+    // Note: we can't omit the operation because we are not guaranteed EnumeratorUpdateIndexAndMode will speculate on the mode.
+    flushRegisters();
 
     if (seenModes.containsAny({ JSPropertyNameEnumerator::OwnStructureMode, JSPropertyNameEnumerator::GenericMode })) {
-
-        if (needsOperation)
-            operationCall = m_jit.branchTest32(MacroAssembler::NonZero, mode, TrustedImm32(JSPropertyNameEnumerator::IndexedMode));
+        operationCall = m_jit.branchTest32(MacroAssembler::NonZero, mode, TrustedImm32(JSPropertyNameEnumerator::IndexedMode));
 
         auto outOfBounds = m_jit.branch32(MacroAssembler::AboveOrEqual, index, MacroAssembler::Address(enumerator, JSPropertyNameEnumerator::endGenericPropertyIndexOffset()));
@@ -13614 +13610 @@
         outOfBounds.link(&m_jit);
         m_jit.moveTrustedValue(jsNull(), resultRegs);
-    }
-
-    if (needsOperation) {
-        if (operationCall.isSet()) {
-            doneCases.append(m_jit.jump());
-            operationCall.link(&m_jit);
-        }
-        callOperation(operationEnumeratorNextUpdatePropertyName, resultRegs, TrustedImmPtr::weakPointer(m_graph, m_graph.globalObjectFor(node->origin.semantic)), index, mode, enumerator);
-        m_jit.exceptionCheck();
-    }
+        doneCases.append(m_jit.jump());
+        operationCall.link(&m_jit);
+    }
+
+    callOperation(operationEnumeratorNextUpdatePropertyName, resultRegs, TrustedImmPtr::weakPointer(m_graph, m_graph.globalObjectFor(node->origin.semantic)), index, mode, enumerator);
+    m_jit.exceptionCheck();
 
     doneCases.link(&m_jit);

trunk/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp

@@ -13139 +13139 @@
 
         if (seenModes.containsAny({ JSPropertyNameEnumerator::OwnStructureMode, JSPropertyNameEnumerator::GenericMode })) {
-            LBasicBlock checkIndex = nullptr;
+            LBasicBlock checkIndex = m_out.newBlock();
             LBasicBlock outOfBoundsBlock = m_out.newBlock();
             LBasicBlock loadPropertyNameBlock = m_out.newBlock();
             continuation = m_out.newBlock();
-
-            if (seenModes.contains(JSPropertyNameEnumerator::IndexedMode)) {
-                checkIndex = m_out.newBlock();
-                operationBlock = m_out.newBlock();
-                m_out.branch(m_out.testIsZero32(mode, m_out.constInt32(JSPropertyNameEnumerator::IndexedMode)), unsure(checkIndex), unsure(operationBlock));
-            }
-
+            operationBlock = m_out.newBlock();
+
+            m_out.branch(m_out.testIsZero32(mode, m_out.constInt32(JSPropertyNameEnumerator::IndexedMode)), unsure(checkIndex), unsure(operationBlock));
             {
-                if (checkIndex)
-                    m_out.appendTo(checkIndex);
+                m_out.appendTo(checkIndex);
                 LValue outOfBounds = m_out.aboveOrEqual(index, m_out.load32(enumerator, m_heaps.JSPropertyNameEnumerator_endGenericPropertyIndex));
                 m_out.branch(outOfBounds, unsure(outOfBoundsBlock), unsure(loadPropertyNameBlock));
@@ -13171 +13166 @@
         }
 
-        if (seenModes.contains(JSPropertyNameEnumerator::IndexedMode)) {
-            if (operationBlock)
-                m_out.appendTo(operationBlock);
-            results.append(m_out.anchor(vmCall(Int64, operationEnumeratorNextUpdatePropertyName, weakPointer(globalObject), index, mode, enumerator)));
-            if (continuation)
-                m_out.jump(continuation);
-        }
-
-        if (continuation)
+        if (operationBlock)
+            m_out.appendTo(operationBlock);
+        // Note: We can't omit the operation because we have no guarantee that the mode will match what we profiled.
+        results.append(m_out.anchor(vmCall(Int64, operationEnumeratorNextUpdatePropertyName, weakPointer(globalObject), index, mode, enumerator)));
+        if (continuation) {
+            m_out.jump(continuation);
             m_out.appendTo(continuation);
+        }
 
         ASSERT(results.size());