Changeset 36462 in webkit for trunk/JavaScriptCore/VM/CTI.cpp

Timestamp:

Sep 15, 2008, 4:33:25 PM (17 years ago)

Author:

[email protected]

Message:

2008-09-15 Gavin Barraclough <​[email protected]>

Reviewed by Geoff Garen.

Inline code generation of eq_null/neq_null for CTI. Uses vptr checking for
StringObjectsThatAreMasqueradingAsBeingUndefined. In the long run, the
masquerading may be handled differently (through the StructureIDs - see bug
#20823).

1% on v8-tests.

• VM/CTI.cpp: (JSC::CTI::emitJumpSlowCaseIfIsJSCell): (JSC::CTI::privateCompileMainPass): (JSC::CTI::privateCompileSlowCases):
• VM/CTI.h:
• VM/Machine.cpp: (JSC::Machine::Machine): (JSC::Machine::cti_op_eq_null): (JSC::Machine::cti_op_neq_null):
• VM/Machine.h: (JSC::Machine::doesMasqueradesAsUndefined):
• kjs/JSWrapperObject.h: (JSC::JSWrapperObject::): (JSC::JSWrapperObject::JSWrapperObject):
• kjs/StringObject.h: (JSC::StringObject::StringObject):
• kjs/StringObjectThatMasqueradesAsUndefined.h: (JSC::StringObjectThatMasqueradesAsUndefined::StringObjectThatMasqueradesAsUndefined):

File:

• trunk/JavaScriptCore/VM/CTI.cpp (modified) (3 diffs)

trunk/JavaScriptCore/VM/CTI.cpp

@@ -318 +318 @@
 }
 
+ALWAYS_INLINE void CTI::emitJumpSlowCaseIfIsJSCell(X86Assembler::RegisterID reg, unsigned opcodeIndex)
+{
+    m_jit.testl_i32r(JSImmediate::TagMask, reg);
+    m_slowCases.append(SlowCaseEntry(m_jit.emitUnlinkedJe(), opcodeIndex));
+}
+
 ALWAYS_INLINE void CTI::emitJumpSlowCaseIfNotJSCell(X86Assembler::RegisterID reg, unsigned opcodeIndex)
 {
@@ -1390 +1396 @@
         }
         case op_eq_null: {
-            emitGetPutArg(instruction[i + 2].u.operand, 0, X86::ecx);
-            emitCall(i, Machine::cti_op_eq_null);
-            emitPutResult(instruction[i + 1].u.operand);
+            emitGetArg(instruction[i + 2].u.operand, X86::edx);
+
+            // go to a slow case either if this is not an immediate, or if the immediate is not undefined/null.
+            emitJumpSlowCaseIfIsJSCell(X86::edx, i);
+            m_jit.andl_i32r(~JSImmediate::ExtendedTagBitUndefined, X86::edx);
+            m_jit.cmpl_i32r(JSImmediate::FullTagTypeNull, X86::edx);
+            m_slowCases.append(SlowCaseEntry(m_jit.emitUnlinkedJne(), i));
+
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::trueImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+
             i += 3;
             break;
         }
         case op_neq_null: {
-            emitGetPutArg(instruction[i + 2].u.operand, 0, X86::ecx);
-            emitCall(i, Machine::cti_op_neq_null);
-            emitPutResult(instruction[i + 1].u.operand);
+            emitGetArg(instruction[i + 2].u.operand, X86::edx);
+
+            // go to a slow case either if this is not an immediate, or if the immediate is not undefined/null.
+            emitJumpSlowCaseIfIsJSCell(X86::edx, i);
+            m_jit.andl_i32r(~JSImmediate::ExtendedTagBitUndefined, X86::edx);
+            m_jit.cmpl_i32r(JSImmediate::FullTagTypeNull, X86::edx);
+            m_slowCases.append(SlowCaseEntry(m_jit.emitUnlinkedJne(), i));
+
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::falseImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+
             i += 3;
             break;
@@ -1848 +1870 @@
         }
         CTI_COMPILE_BINARY_OP_SLOW_CASE(op_mul);
+        case op_eq_null: {
+            m_jit.link(iter->from, m_jit.label());
+
+            // Value is a JSCell - speculate false, check for StringObjectThatMasqueradesAsUndefined.
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::falseImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+            m_jit.cmpl_i32m(reinterpret_cast<unsigned>(m_machine->m_jsStringObjectThatMasqueradesAsUndefinedVptr), X86::edx);
+            m_jit.link(m_jit.emitUnlinkedJne(), m_labels[i + 3]);
+            
+            // Value is a StringObjectThatMasqueradesAsUndefined
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::trueImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+            m_jit.link(m_jit.emitUnlinkedJmp(), m_labels[i + 3]);
+
+            // Value is an immediate other than undefined/null
+            m_jit.link((++iter)->from, m_jit.label());
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::falseImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+            
+            i += 3;
+            break;
+        }
+        case op_neq_null: {
+            m_jit.link(iter->from, m_jit.label());
+
+            // Value is a JSCell - speculate false, check for StringObjectThatMasqueradesAsUndefined.
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::trueImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+            m_jit.cmpl_i32m(reinterpret_cast<unsigned>(m_machine->m_jsStringObjectThatMasqueradesAsUndefinedVptr), X86::edx);
+            m_jit.link(m_jit.emitUnlinkedJne(), m_labels[i + 3]);
+            
+            // Value is a StringObjectThatMasqueradesAsUndefined
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::falseImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+            m_jit.link(m_jit.emitUnlinkedJmp(), m_labels[i + 3]);
+
+            // Value is an immediate other than undefined/null
+            m_jit.link((++iter)->from, m_jit.label());
+            m_jit.movl_i32r(reinterpret_cast<uint32_t>(JSImmediate::trueImmediate()), X86::eax);
+            emitPutResult(instruction[i + 1].u.operand);
+            
+            i += 3;
+            break;
+        }
         default:
             ASSERT_NOT_REACHED();