Separate newobj opcode for string and mdarray

Author: kg

src/coreclr/interpreter/compiler.cpp

@@ -3062,7 +3062,7 @@ int InterpCompiler::GenerateCode(CORINFO_METHOD_INFO* methodInfo)
                 }
                 else
                 {
-                    AddIns(INTOP_NEWOBJ);
+                    AddIns(isStringOrArray ? INTOP_NEWOBJ_VAROBJSIZE : INTOP_NEWOBJ);
                     m_pLastNewIns->data[1] = GetDataItemIndex(ctorClass);
                 }
 

src/coreclr/interpreter/intops.def

@@ -281,6 +281,7 @@ OPDEF(INTOP_CALL, "call", 4, 1, 1, InterpOpMethodHandle)
 OPDEF(INTOP_CALLVIRT, "callvirt", 4, 1, 1, InterpOpMethodHandle)
 OPDEF(INTOP_NEWOBJ, "newobj", 5, 1, 1, InterpOpMethodHandle)
 OPDEF(INTOP_NEWOBJ_VT, "newobj.vt", 5, 1, 1, InterpOpMethodHandle)
+OPDEF(INTOP_NEWOBJ_VAROBJSIZE, "newobj.varobjsize", 5, 1, 1, InterpOpMethodHandle)
 
 OPDEF(INTOP_CALL_HELPER_PP, "call.helper.pp", 5, 1, 0, InterpOpThreeInts)
 

src/coreclr/vm/interpexec.cpp

@@ -1187,40 +1187,15 @@ void InterpExecMethod(InterpreterFrame *pInterpreterFrame, InterpMethodContextFr
                     methodSlot = ip[3];
 
                     MethodTable *pClass = (MethodTable*)pMethod->pDataItems[ip[4]];
-                    // FIXME: Duplicated code from CALL_INTERP_SLOT
-                    size_t targetMethod = (size_t)pMethod->pDataItems[methodSlot];
-                    MethodDesc *pMD = nullptr;
-                    if (targetMethod & INTERP_METHOD_HANDLE_TAG)
-                    {
-                        pMD = (MethodDesc*)(targetMethod & ~INTERP_METHOD_HANDLE_TAG);
-                    }
+                    OBJECTREF objRef = AllocateObject(pClass);
 
-                    // If we are constructing a type with a component size (i.e. a string) its constructor is a special
-                    //  fcall that is basically a static method that returns the new instance.
-                    if (pMD && pClass->HasComponentSize())
-                    {
-                        // Get the address of the fcall that implements the ctor
-                        PCODE code = pMD->TryGetMultiCallableAddrOfCode(CORINFO_ACCESS_ANY);
-                        assert(code);
-
-                        // callArgsOffset points to the ctor arguments, which are what the fcall expects.
-                        // returnOffset points to where the new instance goes, and the fcall will write it there.
-                        InvokeCompiledMethod(pMD, stack + callArgsOffset, stack + returnOffset, code);
-                        ip += 5;
-                        break;
-                    }
-                    else
-                    {
-                        OBJECTREF objRef = AllocateObject(pClass);
-
-                        // This is return value
-                        LOCAL_VAR(returnOffset, OBJECTREF) = objRef;
-                        // Set `this` arg for ctor call
-                        LOCAL_VAR(callArgsOffset, OBJECTREF) = objRef;
-                        ip += 5;
+                    // This is return value
+                    LOCAL_VAR(returnOffset, OBJECTREF) = objRef;
+                    // Set `this` arg for ctor call
+                    LOCAL_VAR(callArgsOffset, OBJECTREF) = objRef;
+                    ip += 5;
 
-                        goto CALL_INTERP_SLOT;
-                    }
+                    goto CALL_INTERP_SLOT;
                 }
                 case INTOP_NEWOBJ_VT:
                 {
@@ -1239,6 +1214,32 @@ void InterpExecMethod(InterpreterFrame *pInterpreterFrame, InterpMethodContextFr
                     ip += 5;
                     goto CALL_INTERP_SLOT;
                 }
+                case INTOP_NEWOBJ_VAROBJSIZE:
+                {
+                    returnOffset = ip[1];
+                    callArgsOffset = ip[2];
+                    methodSlot = ip[3];
+
+                    // FIXME: Duplicated code from CALL_INTERP_SLOT
+                    size_t targetMethod = (size_t)pMethod->pDataItems[methodSlot];
+                    MethodDesc *pMD = nullptr;
+                    if (targetMethod & INTERP_METHOD_HANDLE_TAG)
+                    {
+                        pMD = (MethodDesc*)(targetMethod & ~INTERP_METHOD_HANDLE_TAG);
+                    }
+
+                    // If we are constructing a type with a component size (i.e. a string) its constructor is a special
+                    //  fcall that is basically a static method that returns the new instance.
+                    // Get the address of the fcall that implements the ctor
+                    PCODE code = pMD->TryGetMultiCallableAddrOfCode(CORINFO_ACCESS_ANY);
+                    assert(code);
+
+                    // callArgsOffset points to the ctor arguments, which are what the fcall expects.
+                    // returnOffset points to where the new instance goes, and the fcall will write it there.
+                    InvokeCompiledMethod(pMD, stack + callArgsOffset, stack + returnOffset, code);
+                    ip += 5;
+                    break;
+                }
                 case INTOP_ZEROBLK_IMM:
                     memset(LOCAL_VAR(ip[1], void*), 0, ip[2]);
                     ip += 3;