Changeset 233253 in webkit

Timestamp:

Jun 27, 2018, 4:19:46 AM (7 years ago)

Author:

mark.lam@apple.com

Message:

DFG's compileReallocatePropertyStorage() and compileAllocatePropertyStorage() slow paths should also clear unused properties.
​https://bugs.webkit.org/show_bug.cgi?id=187091
<rdar://problem/41395624>

Reviewed by Yusuke Suzuki.

JSTests:

• stress/regress-187091.js: Added.

Source/JavaScriptCore:

Previously, when compileReallocatePropertyStorage() and compileAllocatePropertyStorage()
take their slow paths, the slow path would jump back to the fast path right after
the emitted code which clears the unused property values. As a result, the
unused properties are not initialized. We've fixed this by adding the slow path
generators before we emit the code to clear the unused properties.

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileAllocatePropertyStorage):
(JSC::DFG::SpeculativeJIT::compileReallocatePropertyStorage):

Location:

trunk

Files:

• JSTests/ChangeLog (modified) (1 diff)
• JSTests/stress/regress-187091.js (added)
• Source/JavaScriptCore/ChangeLog (modified) (1 diff)
• Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp (modified) (4 diffs)

trunk/JSTests/ChangeLog

@@ +1 @@
+2018-06-27  Mark Lam  <mark.lam@apple.com>
+
+        DFG's compileReallocatePropertyStorage() and compileAllocatePropertyStorage() slow paths should also clear unused properties.
+        https://bugs.webkit.org/show_bug.cgi?id=187091
+        <rdar://problem/41395624>
+
+        Reviewed by Yusuke Suzuki.
+
+        * stress/regress-187091.js: Added.
+
 2018-06-27  Yusuke Suzuki  <utatane.tea@gmail.com>
 

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2018-06-27  Mark Lam  <mark.lam@apple.com>
+
+        DFG's compileReallocatePropertyStorage() and compileAllocatePropertyStorage() slow paths should also clear unused properties.
+        https://bugs.webkit.org/show_bug.cgi?id=187091
+        <rdar://problem/41395624>
+
+        Reviewed by Yusuke Suzuki.
+
+        Previously, when compileReallocatePropertyStorage() and compileAllocatePropertyStorage()
+        take their slow paths, the slow path would jump back to the fast path right after
+        the emitted code which clears the unused property values.  As a result, the
+        unused properties are not initialized.  We've fixed this by adding the slow path
+        generators before we emit the code to clear the unused properties.
+
+        * dfg/DFGSpeculativeJIT.cpp:
+        (JSC::DFG::SpeculativeJIT::compileAllocatePropertyStorage):
+        (JSC::DFG::SpeculativeJIT::compileReallocatePropertyStorage):
+
 2018-06-27  Yusuke Suzuki  <utatane.tea@gmail.com>
 

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp

@@ -8937 +8937 @@
     m_jit.emitAllocate(scratchGPR1, JITAllocator::constant(allocator), scratchGPR2, scratchGPR3, slowPath);
     m_jit.addPtr(JITCompiler::TrustedImm32(size + sizeof(IndexingHeader)), scratchGPR1);
-    
+
+    addSlowPathGenerator(
+        slowPathCall(slowPath, this, operationAllocateSimplePropertyStorageWithInitialCapacity, scratchGPR1));
+
     for (ptrdiff_t offset = 0; offset < static_cast<ptrdiff_t>(size); offset += sizeof(void*))
         m_jit.storePtr(TrustedImmPtr(nullptr), JITCompiler::Address(scratchGPR1, -(offset + sizeof(JSValue) + sizeof(void*))));
-        
-    addSlowPathGenerator(
-        slowPathCall(slowPath, this, operationAllocateSimplePropertyStorageWithInitialCapacity, scratchGPR1));
 
     storageResult(scratchGPR1, node);
@@ -8974 +8974 @@
     GPRTemporary scratch2(this);
     GPRTemporary scratch3(this);
-        
+
     GPRReg oldStorageGPR = oldStorage.gpr();
     GPRReg scratchGPR1 = scratch1.gpr();
@@ -8984 +8984 @@
     
     m_jit.addPtr(JITCompiler::TrustedImm32(newSize + sizeof(IndexingHeader)), scratchGPR1);
-        
+
+    addSlowPathGenerator(
+        slowPathCall(slowPath, this, operationAllocateSimplePropertyStorage, scratchGPR1, newSize / sizeof(JSValue)));
+
     for (ptrdiff_t offset = oldSize; offset < static_cast<ptrdiff_t>(newSize); offset += sizeof(void*))
         m_jit.storePtr(TrustedImmPtr(nullptr), JITCompiler::Address(scratchGPR1, -(offset + sizeof(JSValue) + sizeof(void*))));
-
-    addSlowPathGenerator(
-        slowPathCall(slowPath, this, operationAllocateSimplePropertyStorage, scratchGPR1, newSize / sizeof(JSValue)));
 
     // We have scratchGPR1 = new storage, scratchGPR2 = scratch
@@ -8996 +8996 @@
         m_jit.storePtr(scratchGPR2, JITCompiler::Address(scratchGPR1, -(offset + sizeof(JSValue) + sizeof(void*))));
     }
-        
+
     storageResult(scratchGPR1, node);
 }