Changeset 36544 in webkit for trunk/JavaScriptCore/VM/CTI.cpp

Timestamp:

Sep 17, 2008, 12:29:19 PM (17 years ago)

Author:

[email protected]

Message:

2008-09-17 Gavin Barraclough <​[email protected]>

Reviewed by Geoff Garen.

Optimizations for op_call in CTI. Move check for (ctiCode == 0) into JIT code,
move copying of scopeChain for CodeBlocks that needFullScopeChain into head of
functions, instead of checking prior to making the call.

3% on v8-tests (4% on richards, 6% in delta-blue)

• VM/CTI.cpp: (JSC::CTI::compileOpCall): (JSC::CTI::privateCompileSlowCases): (JSC::CTI::privateCompile):
• VM/Machine.cpp: (JSC::Machine::execute): (JSC::Machine::cti_op_call_JSFunction): (JSC::Machine::cti_vm_compile): (JSC::Machine::cti_vm_updateScopeChain): (JSC::Machine::cti_op_construct_JSConstruct):
• VM/Machine.h:

File:

• trunk/JavaScriptCore/VM/CTI.cpp (modified) (5 diffs)

trunk/JavaScriptCore/VM/CTI.cpp

@@ -469 +469 @@
     // This handles JSFunctions
     emitCall(i, ((type == OpConstruct) ? Machine::cti_op_construct_JSConstruct : Machine::cti_op_call_JSFunction));
+    // Check the ctiCode has been generated - if not, this is handled in a slow case.
+    m_jit.testl_rr(X86::eax, X86::eax);
+    m_slowCases.append(SlowCaseEntry(m_jit.emitUnlinkedJe(), i));
     m_jit.call_r(X86::eax);
     
@@ -1942 +1945 @@
         }
         CTI_COMPILE_BINARY_OP_SLOW_CASE(op_mul);
+
+        case op_call:
+        case op_call_eval:
+        case op_construct: {
+            m_jit.link(iter->from, m_jit.label());
+
+            // We jump to this slow case if the ctiCode for the codeBlock has not yet been generated; compile it now.
+            emitCall(i, Machine::cti_vm_compile);
+            m_jit.call_r(X86::eax);
+            
+            // Instead of checking for 0 we could initialize the CodeBlock::ctiCode to point to a trampoline that would trigger the translation.
+
+            // In the interpreter the following actions are performed by op_ret:
+            
+            // Store the scope chain - returned by op_ret in %edx (see below) - to ExecState::m_scopeChain and CTI_ARGS_scopeChain on the stack.
+            emitGetCTIParam(CTI_ARGS_exec, X86::ecx);
+            emitPutCTIParam(X86::edx, CTI_ARGS_scopeChain);
+            m_jit.movl_rm(X86::edx, OBJECT_OFFSET(ExecState, m_scopeChain), X86::ecx);
+            // Restore ExecState::m_callFrame.
+            m_jit.leal_mr(-(m_codeBlock->numLocals + RegisterFile::CallFrameHeaderSize) * sizeof(Register), X86::edi, X86::edx);
+            m_jit.movl_rm(X86::edx, OBJECT_OFFSET(ExecState, m_callFrame), X86::ecx);
+            // Restore CTI_ARGS_codeBlock.
+            emitPutCTIParam(m_codeBlock, CTI_ARGS_codeBlock);
+
+            emitPutResult(instruction[i + 1].u.operand);
+            i += 6;
+            break;
+        }
+
         default:
             ASSERT_NOT_REACHED();
@@ -1959 +1991 @@
     emitGetCTIParam(CTI_ARGS_r, X86::edi); // edi := r
     emitPutToCallFrameHeader(X86::ecx, RegisterFile::CTIReturnEIP);
+
+    // Lazy copy of the scopeChain
+    X86Assembler::JmpSrc callToUpdateScopeChain;
+    if ((m_codeBlock->codeType == FunctionCode) && m_codeBlock->needsFullScopeChain)
+        callToUpdateScopeChain = m_jit.emitCall();
 
     privateCompileMainPass();
@@ -2008 +2045 @@
     }
 
+    if ((m_codeBlock->codeType == FunctionCode) && m_codeBlock->needsFullScopeChain)
+        X86Assembler::link(code, callToUpdateScopeChain, (void*)Machine::cti_vm_updateScopeChain);
+
     // Link absolute addresses for jsr
     for (Vector<JSRInfo>::iterator iter = m_jsrSites.begin(); iter != m_jsrSites.end(); ++iter)
@@ -2017 +2057 @@
         info.hotPathBegin = X86Assembler::getRelocatedAddress(code, m_structureStubCompilationInfo[i].hotPathBegin);
     }
-
 
     m_codeBlock->ctiCode = code;