Changeset 292083 in webkit for trunk/Source/JavaScriptCore/jit/JIT.cpp

Timestamp:

Mar 29, 2022, 5:08:22 PM (3 years ago)

Author:

[email protected]

Message:

[JSC] Use constants buffer to load JSGlobalObject in BaselineJIT thunks
​https://bugs.webkit.org/show_bug.cgi?id=238414

Reviewed by Saam Barati.

Since these thunks are only called from BaselineJIT, we can assume constants
buffer register. And since we are always using 0 index for JSGlobalObject,
we can encode this into these shared thunks directly instead of loading
CodeBlock pointer from the stack.

We also fix using OBJECT_OFFSETOF for JSGlobalObject directly. We should use
it as JSGlobalObject::offsetOfXXX to make it clean and make it annotated that
these fields are accessed by JIT.

This patch also removes UnusedPointer.h since it is no longer used.

• CMakeLists.txt:
• JavaScriptCore.xcodeproj/project.pbxproj:
• jit/JIT.cpp:

(JSC::JIT::JIT):
(JSC::JIT::emitVarReadOnlyCheck):

• jit/JIT.h:
• jit/JITInlines.h:

(JSC::JIT::loadConstant):
(JSC::JIT::loadGlobalObject):

• jit/JITOpcodes.cpp:

(JSC::JIT::emit_op_overrides_has_instance):
(JSC::JIT::valueIsFalseyGenerator):
(JSC::JIT::valueIsTruthyGenerator):
(JSC::JIT::op_throw_handlerGenerator):
(JSC::JIT::op_check_traps_handlerGenerator):

• jit/JITPropertyAccess.cpp:

(JSC::JIT::slow_op_get_by_val_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_get_private_name_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_put_by_val_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_put_private_name_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_del_by_id_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_del_by_val_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_get_by_id_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_get_by_id_with_this_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::slow_op_put_by_id_callSlowOperationThenCheckExceptionGenerator):
(JSC::JIT::generateOpResolveScopeThunk):
(JSC::JIT::generateOpGetFromScopeThunk):
(JSC::JIT::emitVarInjectionCheck):

• jit/UnusedPointer.h: Removed.
• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::offsetOfVarInjectionWatchpoint):
(JSC::JSGlobalObject::offsetOfVarReadOnlyWatchpoint):
(JSC::JSGlobalObject::offsetOfFunctionProtoHasInstanceSymbolFunction):

File:

• trunk/Source/JavaScriptCore/jit/JIT.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/jit/JIT.cpp

@@ -78 +78 @@
     , m_loopOSREntryBytecodeIndex(loopOSREntryBytecodeIndex)
 {
-    m_globalObjectConstant = addToConstantPool(JITConstantPool::Type::GlobalObject);
+    auto globalObjectConstant = addToConstantPool(JITConstantPool::Type::GlobalObject);
+    ASSERT_UNUSED(globalObjectConstant, globalObjectConstant == s_globalObjectConstant);
     m_profiledCodeBlock = codeBlock;
     m_unlinkedCodeBlock = codeBlock->unlinkedCodeBlock();
@@ -138 +139 @@
     if (resolveType == GlobalVar || resolveType == GlobalVarWithVarInjectionChecks) {
         loadGlobalObject(scratchGPR);
-        loadPtr(Address(scratchGPR, OBJECT_OFFSETOF(JSGlobalObject, m_varReadOnlyWatchpoint)), scratchGPR);
+        loadPtr(Address(scratchGPR, JSGlobalObject::offsetOfVarReadOnlyWatchpoint()), scratchGPR);
         addSlowCase(branch8(Equal, Address(scratchGPR, WatchpointSet::offsetOfState()), TrustedImm32(IsInvalidated)));
     }