1stClassStructs: Replace GT_LDOBJ with GT_OBJ

In preparation for using block nodes in assignments, change GT_LDOBJ to GT_OBJ.
Also, eliminate gtFldTreeList, which was only
being used in a transitory fashion for x87
codegen - instead create the nodes on the fly as needed for stack fp codegen.
Additional minor cleanup.

26 files changed, 434 insertions, 533 deletions

diff --git a/src/jit/codegenarm64.cpp b/src/jit/codegenarm64.cpp
index 47efd1bdbf..6297582834 100644
--- a/src/jit/codegenarm64.cpp
+++ b/src/jit/codegenarm64.cpp
@@ -2512,7 +2512,6 @@ CodeGen::genCodeForTreeNode(GenTreePtr treeNode)
                         // this will set both the Z and V flags only when dividendReg is MinInt
                         //
                         emit->emitIns_R_R_R(INS_adds, size, REG_ZR, dividendReg, dividendReg);
-                        
                         inst_JMP(jmpNotEqual, sdivLabel);                  // goto sdiv if the Z flag is clear
                         genJumpToThrowHlpBlk(EJ_vs, SCK_ARITH_EXCPN);      // if the V flags is set throw ArithmeticException
 
@@ -2850,8 +2849,8 @@ CodeGen::genCodeForTreeNode(GenTreePtr treeNode)
         genProduceReg(treeNode);
         break;
 
-    case GT_LDOBJ:
-        genCodeForLdObj(treeNode->AsOp());
+    case GT_OBJ:
+        genCodeForObj(treeNode->AsObj());
         break;
 
     case GT_MULHI:
@@ -6537,36 +6536,36 @@ CodeGen::genIntrinsic(GenTreePtr treeNode)
 }
 
 //---------------------------------------------------------------------
-// genCodeForLdObj - generate code for a GT_LDOBJ node
+// genCodeForObj - generate code for a GT_OBJ node
 //
 // Arguments
-//    treeNode - the GT_LDOBJ node
+//    treeNode - the GT_OBJ node
 //
 // Return value:
 //    None
 //
 
-void CodeGen::genCodeForLdObj(GenTreeOp* treeNode)
+void CodeGen::genCodeForObj(GenTreeObj* objNode)
 {
-    assert(treeNode->OperGet() == GT_LDOBJ);
+    assert(objNode->OperGet() == GT_OBJ);
 
-    GenTree* addr = treeNode->gtOp.gtOp1;
+    GenTree* addr = objNode->gtOp.gtOp1;
     genConsumeAddress(addr);
      
     regNumber addrReg    = addr->gtRegNum;
-    regNumber targetReg  = treeNode->gtRegNum;
-    var_types targetType = treeNode->TypeGet();
+    regNumber targetReg  = objNode->gtRegNum;
+    var_types targetType = objNode->TypeGet();
     emitter * emit       = getEmitter();
 
-    noway_assert(targetType == TYP_STRUCT); 
+    noway_assert(varTypeIsStruct(targetType)); 
     noway_assert(targetReg != REG_NA);
 
-    CORINFO_CLASS_HANDLE ldObjClass = treeNode->gtLdObj.gtClass;
-    int structSize = compiler->info.compCompHnd->getClassSize(ldObjClass);
+    CORINFO_CLASS_HANDLE objClass = objNode->gtObj.gtClass;
+    int structSize = compiler->info.compCompHnd->getClassSize(objClass);
 
     assert(structSize <= 2*TARGET_POINTER_SIZE);
     BYTE gcPtrs[2] = {TYPE_GC_NONE, TYPE_GC_NONE};
-    compiler->info.compCompHnd->getClassGClayout(ldObjClass, &gcPtrs[0]);
+    compiler->info.compCompHnd->getClassGClayout(objClass, &gcPtrs[0]);
 
     var_types type0 = compiler->getJitGCType(gcPtrs[0]);
     var_types type1 = compiler->getJitGCType(gcPtrs[1]);
@@ -6603,7 +6602,7 @@ void CodeGen::genCodeForLdObj(GenTreeOp* treeNode)
     //             ldp     x2, x3, [x0]
     //
     if (remainingSize == 2*TARGET_POINTER_SIZE)
-    { 
+    {
         if (hasGCpointers)
         {
             // We have GC pointers use two ldr instructions
@@ -6691,7 +6690,7 @@ void CodeGen::genCodeForLdObj(GenTreeOp* treeNode)
         noway_assert(targetReg != addrReg);
         getEmitter()->emitIns_R_R_I(INS_ldr, deferAttr, targetReg, addrReg, deferOffset);
     }
-    genProduceReg(treeNode);
+    genProduceReg(objNode);
 }
 
 
diff --git a/src/jit/codegencommon.cpp b/src/jit/codegencommon.cpp
index fbd96eb02b..6eb5e0a522 100644
--- a/src/jit/codegencommon.cpp
+++ b/src/jit/codegencommon.cpp
@@ -842,9 +842,9 @@ void Compiler::compUpdateLifeVar(GenTreePtr tree, VARSET_TP* pLastUseVars)
 #if !defined(_TARGET_AMD64_) // no addr nodes on AMD and experimenting with with encountering vars in 'random' order
     if (ForCodeGen)
     {
-        if (tree->gtOper == GT_LDOBJ)
+        if (tree->gtOper == GT_OBJ)
         {
-            // The tree must have the particular form LDOBJ(ADDR(LCL)); no need to do the check below.
+            // The tree must have the particular form OBJ(ADDR(LCL)); no need to do the check below.
             assert(indirAddrLocal != NULL);
         }
         else if (tree->OperIsIndir())
@@ -1739,9 +1739,9 @@ unsigned CodeGenInterface::InferStructOpSizeAlign(GenTreePtr op, unsigned *align
         op = op->gtOp.gtOp2;
     }
 
-    if (op->gtOper == GT_LDOBJ)
+    if (op->gtOper == GT_OBJ)
     {
-        CORINFO_CLASS_HANDLE clsHnd = op->gtLdObj.gtClass;
+        CORINFO_CLASS_HANDLE clsHnd = op->AsObj()->gtClass;
         opSize    = compiler->info.compCompHnd->getClassSize(clsHnd);
         alignment = roundUp(compiler->info.compCompHnd->getClassAlignmentRequirement(clsHnd), TARGET_POINTER_SIZE);
     }
diff --git a/src/jit/codegenlegacy.cpp b/src/jit/codegenlegacy.cpp
index 846f51df05..8b9f95937d 100644
--- a/src/jit/codegenlegacy.cpp
+++ b/src/jit/codegenlegacy.cpp
@@ -10551,13 +10551,9 @@ LockBinOpCommon:
             return;
         }
 
-        case GT_LDOBJ:
-            // We need to decide whether all GT_LDOBJ nodes should be eliminated in importation/morphing (by
-            // translation into copyblk or ldind), or whether it is legal to have as arguments to this
-            // method, where we have to generate code for them.
-            // On AMD64, at least, we can get here...
-            NYI("Handle GT_LDOBJ, or eliminate them earlier.");
-            unreached();
+        case GT_OBJ:
+            // All GT_OBJ nodes must have been morphed prior to this.
+            noway_assert(!"Should not see a GT_OBJ node during CodeGen.");
 
         default:
 #ifdef DEBUG
@@ -16533,7 +16529,7 @@ size_t              CodeGen::genPushArgList(GenTreePtr  call)
                 arg = arg->gtOp.gtOp2;
             }
 
-            noway_assert(arg->gtOper == GT_LDOBJ 
+            noway_assert(arg->gtOper == GT_OBJ 
                          || arg->gtOper == GT_MKREFANY
                          || arg->gtOper == GT_IND);
             noway_assert((arg->gtFlags & GTF_REVERSE_OPS) == 0);
@@ -16571,12 +16567,12 @@ size_t              CodeGen::genPushArgList(GenTreePtr  call)
             }
             else
             {
-                noway_assert(arg->gtOper == GT_LDOBJ);
+                noway_assert(arg->gtOper == GT_OBJ);
 
-                if (arg->gtLdObj.gtOp1->gtOper == GT_ADDR &&
-                    arg->gtLdObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
+                if (arg->gtObj.gtOp1->gtOper == GT_ADDR &&
+                    arg->gtObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
                 {              
-                    GenTreePtr   structLocalTree  = arg->gtLdObj.gtOp1->gtOp.gtOp1;
+                    GenTreePtr   structLocalTree  = arg->gtObj.gtOp1->gtOp.gtOp1;
                     unsigned     structLclNum     = structLocalTree->gtLclVarCommon.gtLclNum;
                     LclVarDsc *  varDsc           = &compiler->lvaTable[structLclNum];
 
@@ -16598,7 +16594,7 @@ size_t              CodeGen::genPushArgList(GenTreePtr  call)
                         addrReg = 0;
 
                         // Get the number of BYTES to copy to the stack                     
-                        opsz = roundUp(compiler->info.compCompHnd->getClassSize(arg->gtLdObj.gtClass), sizeof(void*));                  
+                        opsz = roundUp(compiler->info.compCompHnd->getClassSize(arg->gtObj.gtClass), sizeof(void*));                  
                         size_t bytesToBeCopied = opsz;
                 
                         // postponedFields is true if we have any postponed fields
@@ -16618,6 +16614,9 @@ size_t              CodeGen::genPushArgList(GenTreePtr  call)
                         regMaskTP  postponedRegKind       = RBM_NONE;
                         size_t     expectedAlignedOffset  = UINT_MAX;
                     
+                        VARSET_TP* deadVarBits = NULL;
+                        compiler->GetPromotedStructDeathVars()->Lookup(structLocalTree, &deadVarBits);
+
                         // Reverse loop, starts pushing from the end of the struct (i.e. the highest field offset)
                         //
                         for (int varNum = varDsc->lvFieldLclStart + varDsc->lvFieldCnt - 1;
@@ -16741,10 +16740,19 @@ size_t              CodeGen::genPushArgList(GenTreePtr  call)
                                             genSinglePush();
                                         }
                                         
-                                        GenTreePtr fieldTree = arg->gtLdObj.gtFldTreeList[(varNum - varDsc->lvFieldLclStart)];
-                                        noway_assert(fieldTree->gtOper == GT_REG_VAR);
 #if FEATURE_STACK_FP_X87
-
+                                        GenTree* fieldTree = new (compiler, GT_REG_VAR) GenTreeLclVar(fieldVarDsc->lvType, varNum, BAD_IL_OFFSET);
+                                        fieldTree->gtOper = GT_REG_VAR;
+                                        fieldTree->gtRegNum = fieldVarDsc->lvRegNum;
+                                        fieldTree->gtRegVar.gtRegNum = fieldVarDsc->lvRegNum;
+                                        if ((arg->gtFlags & GTF_VAR_DEATH) != 0) 
+                                        {
+                                            if (fieldVarDsc->lvTracked && 
+                                                (deadVarBits == NULL || VarSetOps::IsMember(compiler, *deadVarBits, fieldVarDsc->lvVarIndex)))
+                                            {
+                                                fieldTree->gtFlags |= GTF_VAR_DEATH;
+                                            }
+                                        }
                                         genCodeForTreeStackFP_Leaf(fieldTree);
                         
                                         // Take reg to top of stack
@@ -16913,28 +16921,18 @@ size_t              CodeGen::genPushArgList(GenTreePtr  call)
                         break; 
                     }
 
-                    // If we have field tree nodes, we need to update liveset for them
-                    GenTreePtr * fldTreeList = arg->gtLdObj.gtFldTreeList;
-                    if (fldTreeList != NULL)
-                    {
-                        unsigned fieldCount = compiler->lvaTable[structLocalTree->gtLclVarCommon.gtLclNum].lvFieldCnt; 
-                        for (unsigned i = 0; i < fieldCount; i++)
-                        {
-                            if (fldTreeList[i] != NULL) genUpdateLife(fldTreeList[i]);
-                        }
-                    }
                 }
 
-                genCodeForTree(arg->gtLdObj.gtOp1, 0);
-                noway_assert(arg->gtLdObj.gtOp1->gtFlags & GTF_REG_VAL);
-                regNumber reg = arg->gtLdObj.gtOp1->gtRegNum;
+                genCodeForTree(arg->gtObj.gtOp1, 0);
+                noway_assert(arg->gtObj.gtOp1->gtFlags & GTF_REG_VAL);
+                regNumber reg = arg->gtObj.gtOp1->gtRegNum;
                 // Get the number of DWORDS to copy to the stack
-                opsz = roundUp(compiler->info.compCompHnd->getClassSize(arg->gtLdObj.gtClass), sizeof(void*));
+                opsz = roundUp(compiler->info.compCompHnd->getClassSize(arg->gtObj.gtClass), sizeof(void*));
                 unsigned slots = (unsigned)(opsz / sizeof(void*));
 
                 BYTE* gcLayout = new (compiler, CMK_Codegen) BYTE[slots];
 
-                compiler->info.compCompHnd->getClassGClayout(arg->gtLdObj.gtClass, gcLayout);
+                compiler->info.compCompHnd->getClassGClayout(arg->gtObj.gtClass, gcLayout);
 
                 BOOL bNoneGC = TRUE;
                 for (int i = slots - 1; i >= 0; --i)
@@ -17385,14 +17383,14 @@ DEFERRED:
                 genUpdateLife(op1);
                 arg = arg->gtOp.gtOp2;
             }
-            noway_assert((arg->OperGet() == GT_LDOBJ) || (arg->OperGet() == GT_MKREFANY));
+            noway_assert((arg->OperGet() == GT_OBJ) || (arg->OperGet() == GT_MKREFANY));
 
             CORINFO_CLASS_HANDLE clsHnd;
             unsigned             argAlign;
             unsigned             slots;
             BYTE*                gcLayout = NULL;
 
-            // If the struct being passed is a LDOBJ of a local struct variable that is promoted (in the
+            // If the struct being passed is a OBJ of a local struct variable that is promoted (in the
             // INDEPENDENT fashion, which doesn't require writes to be written through to the variable's
             // home stack loc) "promotedStructLocalVarDesc" will be set to point to the local variable
             // table entry for the promoted struct local.  As we fill slots with the contents of a
@@ -17406,9 +17404,9 @@ DEFERRED:
             unsigned             promotedStructOffsetOfFirstStackSlot = 0;
             unsigned             argOffsetOfFirstStackSlot = UINT32_MAX;  // Indicates uninitialized.
 
-            if (arg->OperGet() == GT_LDOBJ)
+            if (arg->OperGet() == GT_OBJ)
             {
-                clsHnd = arg->gtLdObj.gtClass;
+                clsHnd = arg->gtObj.gtClass;
                 unsigned originalSize = compiler->info.compCompHnd->getClassSize(clsHnd);
                 argAlign = roundUp(compiler->info.compCompHnd->getClassAlignmentRequirement(clsHnd), TARGET_POINTER_SIZE);
                 argSize = (unsigned)(roundUp(originalSize, TARGET_POINTER_SIZE));
@@ -17420,10 +17418,10 @@ DEFERRED:
                 compiler->info.compCompHnd->getClassGClayout(clsHnd, gcLayout);
 
                 // Are we loading a promoted struct local var?
-                if (arg->gtLdObj.gtOp1->gtOper == GT_ADDR &&
-                    arg->gtLdObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
+                if (arg->gtObj.gtOp1->gtOper == GT_ADDR &&
+                    arg->gtObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
                 {
-                    structLocalTree               = arg->gtLdObj.gtOp1->gtOp.gtOp1;
+                    structLocalTree               = arg->gtObj.gtOp1->gtOp.gtOp1;
                     unsigned     structLclNum     = structLocalTree->gtLclVarCommon.gtLclNum;
                     LclVarDsc *  varDsc           = &compiler->lvaTable[structLclNum];
 
@@ -17461,17 +17459,17 @@ DEFERRED:
 
             // This code passes a TYP_STRUCT by value using the outgoing arg space var
             //
-            if (arg->OperGet() == GT_LDOBJ)
+            if (arg->OperGet() == GT_OBJ)
             {
                 regNumber regSrc = REG_STK;
-                regNumber regTmp = REG_STK;  // This will get set below if the ldobj is not of a promoted struct local.
+                regNumber regTmp = REG_STK;  // This will get set below if the obj is not of a promoted struct local.
                 int cStackSlots = 0;
 
                 if (promotedStructLocalVarDesc == NULL)
                 {
-                    genComputeReg(arg->gtLdObj.gtOp1, 0,  RegSet::ANY_REG, RegSet::KEEP_REG);
-                    noway_assert(arg->gtLdObj.gtOp1->gtFlags & GTF_REG_VAL);
-                    regSrc = arg->gtLdObj.gtOp1->gtRegNum;
+                    genComputeReg(arg->gtObj.gtOp1, 0,  RegSet::ANY_REG, RegSet::KEEP_REG);
+                    noway_assert(arg->gtObj.gtOp1->gtFlags & GTF_REG_VAL);
+                    regSrc = arg->gtObj.gtOp1->gtRegNum;
                 }
                          
                 // The number of bytes to add "argOffset" to get the arg offset of the current slot.
@@ -18259,7 +18257,7 @@ void CodeGen::SetupLateArgs(GenTreePtr call)
                 genUpdateLife(op1);
                 arg = arg->gtOp.gtOp2;
             }
-            noway_assert((arg->OperGet() == GT_LDOBJ) || (arg->OperGet() == GT_LCL_VAR) || (arg->OperGet() == GT_MKREFANY));
+            noway_assert((arg->OperGet() == GT_OBJ) || (arg->OperGet() == GT_LCL_VAR) || (arg->OperGet() == GT_MKREFANY));
 
             // This code passes a TYP_STRUCT by value using
             // the argument registers first and 
@@ -18322,7 +18320,7 @@ void CodeGen::SetupLateArgs(GenTreePtr call)
             // that go dead after this use of the variable in the argument list.
             regMaskTP deadFieldVarRegs = RBM_NONE;
 
-            // If the struct being passed is a LDOBJ of a local struct variable that is promoted (in the
+            // If the struct being passed is an OBJ of a local struct variable that is promoted (in the
             // INDEPENDENT fashion, which doesn't require writes to be written through to the variables
             // home stack loc) "promotedStructLocalVarDesc" will be set to point to the local variable
             // table entry for the promoted struct local.  As we fill slots with the contents of a
@@ -18338,13 +18336,13 @@ void CodeGen::SetupLateArgs(GenTreePtr call)
             
             BYTE *    gcLayout = NULL;
             regNumber regSrc = REG_NA;
-            if (arg->gtOper == GT_LDOBJ)
+            if (arg->gtOper == GT_OBJ)
             {
                 // Are we loading a promoted struct local var?
-                if (arg->gtLdObj.gtOp1->gtOper == GT_ADDR &&
-                    arg->gtLdObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
+                if (arg->gtObj.gtOp1->gtOper == GT_ADDR &&
+                    arg->gtObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
                 {
-                    structLocalTree               = arg->gtLdObj.gtOp1->gtOp.gtOp1;
+                    structLocalTree               = arg->gtObj.gtOp1->gtOp.gtOp1;
                     unsigned     structLclNum     = structLocalTree->gtLclVarCommon.gtLclNum;
                     LclVarDsc *  varDsc           = &compiler->lvaTable[structLclNum];
 
@@ -18366,16 +18364,16 @@ void CodeGen::SetupLateArgs(GenTreePtr call)
                 {
                     // If it's not a promoted struct variable, set "regSrc" to the address
                     // of the struct local.
-                    genComputeReg(arg->gtLdObj.gtOp1, regNeedMask, RegSet::EXACT_REG, RegSet::KEEP_REG);
-                    noway_assert(arg->gtLdObj.gtOp1->gtFlags & GTF_REG_VAL);
-                    regSrc = arg->gtLdObj.gtOp1->gtRegNum;
+                    genComputeReg(arg->gtObj.gtOp1, regNeedMask, RegSet::EXACT_REG, RegSet::KEEP_REG);
+                    noway_assert(arg->gtObj.gtOp1->gtFlags & GTF_REG_VAL);
+                    regSrc = arg->gtObj.gtOp1->gtRegNum;
                     // Remove this register from the set of registers that we pick from, unless slots equals 1
                     if (slots > 1)
                         regNeedMask &= ~genRegMask(regSrc);
                 }
 
                 gcLayout = new (compiler, CMK_Codegen) BYTE[slots];
-                compiler->info.compCompHnd->getClassGClayout(arg->gtLdObj.gtClass, gcLayout);
+                compiler->info.compCompHnd->getClassGClayout(arg->gtObj.gtClass, gcLayout);
             }
             else if (arg->gtOper == GT_LCL_VAR)
             {
@@ -18612,7 +18610,7 @@ void CodeGen::SetupLateArgs(GenTreePtr call)
                 } while (needOverwriteRegSrc != overwriteRegSrc);
             }
 
-            if ((arg->gtOper == GT_LDOBJ )&& (promotedStructLocalVarDesc == NULL))
+            if ((arg->gtOper == GT_OBJ) && (promotedStructLocalVarDesc == NULL))
             {
                 regSet.rsMarkRegFree(genRegMask(regSrc));
             }
diff --git a/src/jit/codegenlinear.h b/src/jit/codegenlinear.h
index 08a7da24c8..5e34f05245 100644
--- a/src/jit/codegenlinear.h
+++ b/src/jit/codegenlinear.h
@@ -54,7 +54,7 @@
 #endif
 
 #ifdef _TARGET_ARM64_
-    void                genCodeForLdObj(GenTreeOp* treeNode);
+    void                genCodeForObj(GenTreeObj* treeNode);
 #endif
 
 #ifdef FEATURE_SIMD
@@ -67,6 +67,7 @@
 
     instruction         getOpForSIMDIntrinsic(SIMDIntrinsicID intrinsicId, var_types baseType, unsigned *ival = nullptr);
     void                genSIMDScalarMove(var_types type, regNumber target, regNumber src, SIMDScalarMoveType moveType);
+    void                genSIMDZero(var_types targetType, var_types baseType, regNumber targetReg);
     void                genSIMDIntrinsicInit(GenTreeSIMD* simdNode);
     void                genSIMDIntrinsicInitN(GenTreeSIMD* simdNode);
     void                genSIMDIntrinsicInitArray(GenTreeSIMD* simdNode);
diff --git a/src/jit/codegenxarch.cpp b/src/jit/codegenxarch.cpp
index 3dc7d2d80b..0258c1fabc 100644
--- a/src/jit/codegenxarch.cpp
+++ b/src/jit/codegenxarch.cpp
@@ -3608,7 +3608,7 @@ void CodeGen::genStructPutArgUnroll(GenTreePutArgStk* putArgNode, unsigned baseV
 
     assert(src->isContained());
 
-    assert(src->gtOper == GT_LDOBJ);
+    assert(src->gtOper == GT_OBJ);
 
     if (!src->gtOp.gtOp1->isContained())
     {
@@ -3628,7 +3628,7 @@ void CodeGen::genStructPutArgUnroll(GenTreePutArgStk* putArgNode, unsigned baseV
         size_t slots = size / XMM_REGSIZE_BYTES;
 
         assert(putArgNode->gtGetOp1()->isContained());
-        assert(putArgNode->gtGetOp1()->gtOp.gtOper == GT_LDOBJ);
+        assert(putArgNode->gtGetOp1()->gtOp.gtOper == GT_OBJ);
 
         // TODO: In the below code the load and store instructions are for 16 bytes, but the 
         //          type is EA_8BYTE. The movdqa/u are 16 byte instructions, so it works, but
@@ -3636,7 +3636,7 @@ void CodeGen::genStructPutArgUnroll(GenTreePutArgStk* putArgNode, unsigned baseV
         while (slots-- > 0)
         {
             // Load
-            genCodeForLoadOffset(INS_movdqu, EA_8BYTE, xmmReg, src->gtGetOp1(), offset); // Load the address of the child of the LdObj node.
+            genCodeForLoadOffset(INS_movdqu, EA_8BYTE, xmmReg, src->gtGetOp1(), offset); // Load the address of the child of the Obj node.
 
             // Store
             emit->emitIns_S_R(INS_movdqu,
@@ -5012,7 +5012,7 @@ void CodeGen::genConsumePutStructArgStk(GenTreePutArgStk* putArgNode, regNumber
 
     // Get the GT_ADDR node, which is GT_LCL_VAR_ADDR (asserted below.)
     GenTree* src = putArgNode->gtGetOp1();
-    assert((src->gtOper == GT_LDOBJ) || ((src->gtOper == GT_IND && varTypeIsSIMD(src))));
+    assert((src->gtOper == GT_OBJ) || ((src->gtOper == GT_IND && varTypeIsSIMD(src))));
     src = src->gtGetOp1();
     
     size_t size = putArgNode->getArgSize();
@@ -5650,8 +5650,8 @@ void CodeGen::genCallInstruction(GenTreePtr node)
             {
                 assert(arg->OperGet() == GT_PUTARG_STK);
 
-                GenTreeLdObj* ldObj = arg->gtGetOp1()->AsLdObj();
-                stackArgBytes = compiler->info.compCompHnd->getClassSize(ldObj->gtClass);
+                GenTreeObj* obj = arg->gtGetOp1()->AsObj();
+                stackArgBytes = compiler->info.compCompHnd->getClassSize(obj->gtClass);
             }
             else
 #endif // FEATURE_UNIX_AMD64_STRUCT_PASSING
@@ -8203,7 +8203,7 @@ CodeGen::genPutStructArgStk(GenTreePtr treeNode, unsigned baseVarNum)
         genConsumePutStructArgStk(putArgStk, REG_RDI, REG_RSI, REG_NA, baseVarNum);
         GenTreePtr   dstAddr = putArgStk;
         GenTreePtr   src = putArgStk->gtOp.gtOp1;
-        assert(src->OperGet() == GT_LDOBJ);
+        assert(src->OperGet() == GT_OBJ);
         GenTreePtr   srcAddr = src->gtGetOp1();
 
         unsigned slots = putArgStk->gtNumSlots;
diff --git a/src/jit/compiler.cpp b/src/jit/compiler.cpp
index eb3a3c1842..e39ce6258c 100644
--- a/src/jit/compiler.cpp
+++ b/src/jit/compiler.cpp
@@ -444,16 +444,16 @@ void Compiler::getStructGcPtrsFromOp(GenTreePtr op, BYTE *gcPtrsOut)
     assert(op->TypeGet() == TYP_STRUCT);
 
 #ifdef _TARGET_ARM64_
-    if (op->OperGet() == GT_LDOBJ)
+    if (op->OperGet() == GT_OBJ)
     {
-        CORINFO_CLASS_HANDLE ldObjClass = op->gtLdObj.gtClass;
+        CORINFO_CLASS_HANDLE objClass = op->gtObj.gtClass;
 
-        int structSize = info.compCompHnd->getClassSize(ldObjClass);
+        int structSize = info.compCompHnd->getClassSize(objClass);
         assert(structSize <= 2*TARGET_POINTER_SIZE);
 
         BYTE gcPtrsTmp[2] = {TYPE_GC_NONE, TYPE_GC_NONE};
 
-        info.compCompHnd->getClassGClayout(ldObjClass, &gcPtrsTmp[0]);
+        info.compCompHnd->getClassGClayout(objClass, &gcPtrsTmp[0]);
 
         gcPtrsOut[0] = gcPtrsTmp[0];
         gcPtrsOut[1] = gcPtrsTmp[1];
@@ -1161,7 +1161,7 @@ void                Compiler::compDisplayStaticSizes(FILE* fout)
     fprintf(fout, "Size of GenTreeStoreInd     = %3u\n", sizeof(GenTreeStoreInd));
     fprintf(fout, "Size of GenTreeRetExpr      = %3u\n", sizeof(GenTreeRetExpr));
     fprintf(fout, "Size of GenTreeStmt         = %3u\n", sizeof(GenTreeStmt));
-    fprintf(fout, "Size of GenTreeLdObj        = %3u\n", sizeof(GenTreeLdObj));
+    fprintf(fout, "Size of GenTreeObj          = %3u\n", sizeof(GenTreeObj));
     fprintf(fout, "Size of GenTreeClsVar       = %3u\n", sizeof(GenTreeClsVar));
     fprintf(fout, "Size of GenTreeArgPlace     = %3u\n", sizeof(GenTreeArgPlace));
     fprintf(fout, "Size of GenTreeLabel        = %3u\n", sizeof(GenTreeLabel));
@@ -2512,7 +2512,6 @@ void                Compiler::compInitOptions(CORJIT_FLAGS* jitFlags)
 
     if (compIsForInlining() || compIsForImportOnly())
         return;
-                   
     // The rest of the opts fields that we initialize here
     // should only be used when we generate code for the method
     // They should not be used when importing or inlining
@@ -4946,7 +4945,7 @@ int           Compiler::compCompileHelper (CORINFO_MODULE_HANDLE            clas
                 prejitResult.SetReported();
             }
         }
-        else
+        else 
         {
             // We are jitting the root method, or inlining.
             fgFindBasicBlocks();
@@ -4956,7 +4955,7 @@ int           Compiler::compCompileHelper (CORINFO_MODULE_HANDLE            clas
         if (compDonotInline())
         {
             goto _Next;
-        }          
+        }        
 
         compSetOptimizationLevel();
 
diff --git a/src/jit/compiler.h b/src/jit/compiler.h
index 1e58ee989d..aee4a12005 100644
--- a/src/jit/compiler.h
+++ b/src/jit/compiler.h
@@ -1767,7 +1767,7 @@ protected:
                                              GenTreePtr src, GenTreePtr size,
                                              bool volatil);
 public:
-    GenTreeLdObj*           gtNewLdObjNode  (CORINFO_CLASS_HANDLE structHnd, GenTreePtr addr);
+    GenTreeObj*             gtNewObjNode    (CORINFO_CLASS_HANDLE structHnd, GenTreePtr addr);
 
     GenTreeBlkOp*           gtNewCpObjNode  (GenTreePtr dst, GenTreePtr src,
                                              CORINFO_CLASS_HANDLE structHnd, bool volatil);
@@ -6678,10 +6678,10 @@ public :
                                                             regMaskTP* pArgSkippedRegMask);
 #endif // _TARGET_ARM_
 
-    // If "tree" is a indirection (GT_IND, or GT_LDOBJ) whose arg is an ADDR, whose arg is a LCL_VAR, return that LCL_VAR node, else NULL.
+    // If "tree" is a indirection (GT_IND, or GT_OBJ) whose arg is an ADDR, whose arg is a LCL_VAR, return that LCL_VAR node, else NULL.
     GenTreePtr          fgIsIndirOfAddrOfLocal(GenTreePtr tree);
 
-    // This is indexed by GT_LDOBJ nodes that are address of promoted struct variables, which
+    // This is indexed by GT_OBJ nodes that are address of promoted struct variables, which
     // have been annotated with the GTF_VAR_DEATH flag.  If such a node is *not* mapped in this
     // table, one may assume that all the (tracked) field vars die at this point.  Otherwise,
     // the node maps to a pointer to a VARSET_TP, containing set bits for each of the tracked field
@@ -6874,25 +6874,48 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
     CORINFO_CLASS_HANDLE    SIMDVectorHandle;
 
     // Get the handle for a SIMD type.
-    // For the purposes of type handles, we treat all Vector<T> as Vector<float> in the JIT,
-    // as the actual instantiation type doesn't impact this code (that is always captured,
-    // where semantically meaningful, in the "baseType" of SIMD nodes or lclVars.
-    CORINFO_CLASS_HANDLE    getStructHandleForSIMDType(var_types type)
-    {
-        noway_assert(varTypeIsSIMD(type));
-        CORINFO_CLASS_HANDLE structHnd;
-        switch (type)
+    CORINFO_CLASS_HANDLE    gtGetStructHandleForSIMD(var_types simdType, var_types simdBaseType)
+    {
+        if (simdBaseType == TYP_FLOAT)
         {
-            case TYP_SIMD8:     structHnd = SIMDVector2Handle;                 break;
-            case TYP_SIMD12:    structHnd = SIMDVector3Handle;                 break;
-            case TYP_SIMD16:    structHnd = SIMDVector4Handle;                 break;
-#ifdef FEATURE_AVX_SUPPORT
-            case TYP_SIMD32:    structHnd = SIMDFloatHandle;                   break;
-#endif // FEATURE_AVX_SUPPORT
-            default:            unreached();
+            switch(simdType)
+            {
+            case TYP_SIMD8:
+                return SIMDVector2Handle;
+            case TYP_SIMD12:
+                return SIMDVector3Handle;
+            case TYP_SIMD16:
+                if ((getSIMDVectorType() == TYP_SIMD32) ||
+                    (SIMDVector4Handle != NO_CLASS_HANDLE))
+                {
+                    return SIMDVector4Handle;
+                }
+                break;
+            case TYP_SIMD32:
+                break;
+            default:
+                unreached();
+            }
         }
-        return structHnd;    
+        assert(simdType == getSIMDVectorType());
+        switch(simdBaseType)
+        {
+        case TYP_FLOAT:     return SIMDFloatHandle;
+        case TYP_DOUBLE:    return SIMDDoubleHandle;
+        case TYP_INT:       return SIMDIntHandle;
+        case TYP_CHAR:      return SIMDUShortHandle;
+        case TYP_USHORT:    return SIMDUShortHandle;
+        case TYP_UBYTE:     return SIMDUByteHandle;
+        case TYP_SHORT:     return SIMDShortHandle;
+        case TYP_BYTE:      return SIMDByteHandle;
+        case TYP_LONG:      return SIMDLongHandle;
+        case TYP_UINT:      return SIMDUIntHandle;
+        case TYP_ULONG:     return SIMDULongHandle;
+        default:            assert(!"Didn't find a class handle for simdType");
+        }
+        return NO_CLASS_HANDLE;
     }
+
     // SIMD Methods
     CORINFO_METHOD_HANDLE   SIMDVectorFloat_set_Item;
     CORINFO_METHOD_HANDLE   SIMDVectorFloat_get_Length;
diff --git a/src/jit/flowgraph.cpp b/src/jit/flowgraph.cpp
index 583a93be2b..923e4ae56d 100644
--- a/src/jit/flowgraph.cpp
+++ b/src/jit/flowgraph.cpp
@@ -6586,7 +6586,7 @@ bool                Compiler::fgIsCommaThrow(GenTreePtr tree,
 GenTreePtr          Compiler::fgIsIndirOfAddrOfLocal(GenTreePtr tree)
 {
     GenTreePtr res = nullptr;
-    if (tree->OperGet() == GT_LDOBJ || tree->OperIsIndir())
+    if (tree->OperGet() == GT_OBJ || tree->OperIsIndir())
     {
         GenTreePtr addr = tree->gtOp.gtOp1;
 
@@ -17707,25 +17707,6 @@ void                Compiler::fgSetTreeSeqHelper(GenTreePtr tree)
             return;
         }
 
-        /* Handle the case of an LDOBJ with a field list */
-
-        GenTreePtr lclVarTree;
-        if ((oper == GT_LDOBJ) &&
-            tree->gtLdObj.gtFldTreeList != NULL &&
-            impIsAddressInLocal(tree->gtOp.gtOp1, &lclVarTree))
-        {
-            GenTreePtr* fldTreeList = tree->gtLdObj.gtFldTreeList;
-            unsigned fieldCount = lvaTable[lclVarTree->gtLclVarCommon.gtLclNum].lvFieldCnt;
-
-            for (unsigned i = 0; i < fieldCount; i++)
-            {
-                if (fldTreeList[i] != NULL)
-                {
-                    fgSetTreeSeqHelper(fldTreeList[i]);
-                }
-            }
-        }
-
         /* Check for a nilary operator */
 
         if (op1 == NULL)
@@ -20749,27 +20730,6 @@ void Compiler::fgDebugCheckNodeLinks(BasicBlock* block, GenTree* node)
         {
             GenTreePtr lclVarTree;
             expectedPrevTree = tree->gtOp.gtOp1;
-            if ((tree->gtOper == GT_LDOBJ) &&
-                (tree->gtLdObj.gtFldTreeList != NULL) &&
-                impIsAddressInLocal(tree->gtOp.gtOp1, &lclVarTree))
-            {
-                GenTreePtr* fldTreeList = tree->gtLdObj.gtFldTreeList;
-                GenTreePtr prev = NULL;
-                unsigned fieldCount = lvaTable[lclVarTree->gtLclVarCommon.gtLclNum].lvFieldCnt;
-
-                for (unsigned i = 0; i < fieldCount; i++)
-                {
-                    if (fldTreeList[i] != NULL)
-                    {
-                        if (prev != NULL)
-                        {
-                            noway_assert(fldTreeList[i]->gtPrev == prev);
-                        }
-                        prev = fldTreeList[i];
-                    }
-                }
-                noway_assert(lclVarTree->gtPrev == prev);
-            }
         }
         else if (tree->OperIsBinary() && tree->gtOp.gtOp1)
         {
@@ -21525,7 +21485,7 @@ GenTreePtr Compiler::fgGetStructAsStructPtr(GenTreePtr tree)
     noway_assert((tree->gtOper == GT_LCL_VAR) ||
                  (tree->gtOper == GT_FIELD)   ||
                  (tree->gtOper == GT_IND)     ||
-                 (tree->gtOper == GT_LDOBJ)   ||
+                 (tree->gtOper == GT_OBJ)     ||
                  tree->OperIsSIMD()           ||
                  // tree->gtOper == GT_CALL     || cannot get address of call.
                  // tree->gtOper == GT_MKREFANY || inlining should've been aborted due to mkrefany opcode.
@@ -21534,7 +21494,7 @@ GenTreePtr Compiler::fgGetStructAsStructPtr(GenTreePtr tree)
 
     switch (tree->OperGet())
     {
-    case GT_LDOBJ:
+    case GT_OBJ:
     case GT_IND:
         return tree->gtOp.gtOp1;
 
@@ -22431,29 +22391,19 @@ GenTreePtr      Compiler::fgInlinePrependStatements(InlineInfo* inlineInfo)
                 {
                     /* Create the temp assignment for this argument */
 
-                    CORINFO_CLASS_HANDLE structType = DUMMY_INIT(0);
+                    CORINFO_CLASS_HANDLE structHnd = DUMMY_INIT(0);
 
                     if (varTypeIsStruct(lclVarInfo[argNum].lclTypeInfo))
                     {
-                        if (inlArgInfo[argNum].argNode->gtOper == GT_LDOBJ)
-                        {
-                            structType = inlArgInfo[argNum].argNode->gtLdObj.gtClass;
-                        }
-                        else if (inlArgInfo[argNum].argNode->gtOper == GT_MKREFANY)
-                        {
-                            structType = lclVarInfo[argNum].lclVerTypeInfo.GetClassHandle();
-                        }
-                        else
-                        {
-                            noway_assert(!"Unknown struct type");
-                        }
+                        structHnd = gtGetStructHandleIfPresent(inlArgInfo[argNum].argNode);
+                        noway_assert(structHnd != NO_CLASS_HANDLE);
                     }
 
                     // Unsafe value cls check is not needed for argTmpNum here since in-linee compiler instance would have
                     // iterated over these and marked them accordingly.
                     impAssignTempGen(inlArgInfo[argNum].argTmpNum,
                                      inlArgInfo[argNum].argNode,
-                                     structType,
+                                     structHnd,
                                      (unsigned)CHECK_SPILL_NONE,
                                      & afterStmt,
                                      callILOffset,
@@ -22496,10 +22446,10 @@ GenTreePtr      Compiler::fgInlinePrependStatements(InlineInfo* inlineInfo)
                 {
                     noway_assert(inlArgInfo[argNum].argIsUsed == false);
 
-                    if (inlArgInfo[argNum].argNode->gtOper == GT_LDOBJ ||
+                    if (inlArgInfo[argNum].argNode->gtOper == GT_OBJ ||
                         inlArgInfo[argNum].argNode->gtOper == GT_MKREFANY)
                     {
-                        // Don't put GT_LDOBJ node under a GT_COMMA.
+                        // Don't put GT_OBJ node under a GT_COMMA.
                         // Codegen can't deal with it.
                         // Just hang the address here in case there are side-effect.
                         newStmt = gtNewStmt(gtUnusedValNode(inlArgInfo[argNum].argNode->gtOp.gtOp1), callILOffset);
diff --git a/src/jit/gentree.cpp b/src/jit/gentree.cpp
index f8a1eeb4b6..cad84177c4 100755
--- a/src/jit/gentree.cpp
+++ b/src/jit/gentree.cpp
@@ -259,7 +259,7 @@ void                GenTree::InitNodeSize()
     GenTree::s_gtNodeSizes[GT_ARR_INDEX       ] = TREE_NODE_SZ_LARGE;
     GenTree::s_gtNodeSizes[GT_ARR_OFFSET      ] = TREE_NODE_SZ_LARGE;
     GenTree::s_gtNodeSizes[GT_RET_EXPR        ] = TREE_NODE_SZ_LARGE;
-    GenTree::s_gtNodeSizes[GT_LDOBJ           ] = TREE_NODE_SZ_LARGE;
+    GenTree::s_gtNodeSizes[GT_OBJ             ] = TREE_NODE_SZ_LARGE;
     GenTree::s_gtNodeSizes[GT_FIELD           ] = TREE_NODE_SZ_LARGE;
     GenTree::s_gtNodeSizes[GT_STMT            ] = TREE_NODE_SZ_LARGE;
     GenTree::s_gtNodeSizes[GT_CMPXCHG         ] = TREE_NODE_SZ_LARGE;
@@ -331,7 +331,7 @@ void                GenTree::InitNodeSize()
     static_assert_no_msg(sizeof(GenTreeCpObj)         <= TREE_NODE_SZ_LARGE); // *** large node
     static_assert_no_msg(sizeof(GenTreeRetExpr)       <= TREE_NODE_SZ_LARGE); // *** large node
     static_assert_no_msg(sizeof(GenTreeStmt)          <= TREE_NODE_SZ_LARGE); // *** large node
-    static_assert_no_msg(sizeof(GenTreeLdObj)         <= TREE_NODE_SZ_LARGE); // *** large node
+    static_assert_no_msg(sizeof(GenTreeObj)           <= TREE_NODE_SZ_LARGE); // *** large node
     static_assert_no_msg(sizeof(GenTreeClsVar)        <= TREE_NODE_SZ_SMALL);
     static_assert_no_msg(sizeof(GenTreeArgPlace)      <= TREE_NODE_SZ_SMALL);
     static_assert_no_msg(sizeof(GenTreeLabel)         <= TREE_NODE_SZ_SMALL);
@@ -1252,8 +1252,8 @@ AGAIN:
             case GT_CAST:
                 if (op1->gtCast.gtCastType != op2->gtCast.gtCastType) return false;
                 break;
-            case GT_LDOBJ:
-                if (op1->gtLdObj.gtClass != op2->gtLdObj.gtClass) return false;
+            case GT_OBJ:
+                if (op1->AsObj()->gtClass != op2->AsObj()->gtClass) return false;
                 break;
 
                 // For the ones below no extra argument matters for comparison.
@@ -1759,8 +1759,8 @@ AGAIN:
             case GT_CAST:
                 hash ^= tree->gtCast.gtCastType;
                 break;
-            case GT_LDOBJ:
-                hash ^= static_cast<unsigned>(reinterpret_cast<uintptr_t>(tree->gtLdObj.gtClass));
+            case GT_OBJ:
+                hash ^= static_cast<unsigned>(reinterpret_cast<uintptr_t>(tree->gtObj.gtClass));
                 break;
             case GT_INDEX:
                 hash += tree->gtIndex.gtIndElemSize;
@@ -3113,7 +3113,7 @@ COMMON_CNS:
                 break;
 
             case GT_MKREFANY:
-            case GT_LDOBJ:
+            case GT_OBJ:
                 level  = gtSetEvalOrder(tree->gtOp.gtOp1);
                 ftreg |= tree->gtOp.gtOp1->gtRsvdRegs;
                 costEx = tree->gtOp.gtOp1->gtCostEx + 1;
@@ -4545,10 +4545,10 @@ GenTreePtr*         GenTree::gtGetChildPointer(GenTreePtr parent)
 
 #if !FEATURE_MULTIREG_ARGS
         // Note that when FEATURE_MULTIREG_ARGS==1 
-        //  a GT_LDOBJ node is handled above by the default case
-    case GT_LDOBJ:
-        // Any GT_LDOBJ with a field must be lowered before this point.
-        noway_assert(!"GT_LDOBJ encountered in GenTree::gtGetChildPointer");
+        //  a GT_OBJ node is handled above by the default case
+    case GT_OBJ:
+        // Any GT_OBJ with a field must be lowered before this point.
+        noway_assert(!"GT_OBJ encountered in GenTree::gtGetChildPointer");
         break;
 #endif // !FEATURE_MULTIREG_ARGS
 
@@ -4717,10 +4717,7 @@ bool                GenTree::OperMayThrow()
     case GT_ARR_INDEX:
     case GT_CATCH_ARG:
     case GT_ARR_LENGTH:
-    case GT_LDOBJ:
-    case GT_INITBLK:
-    case GT_COPYBLK:
-    case GT_COPYOBJ:
+    case GT_OBJ:
     case GT_LCLHEAP:
     case GT_CKFINITE:
     case GT_NULLCHECK:
@@ -5450,12 +5447,12 @@ GenTreePtr          Compiler::gtNewAssignNode(GenTreePtr dst, GenTreePtr src DEB
     return asg;
 }
 
-// Creates a new LdObj node.
-GenTreeLdObj* Compiler::gtNewLdObjNode(CORINFO_CLASS_HANDLE structHnd, GenTree* addr)
+// Creates a new Obj node.
+GenTreeObj* Compiler::gtNewObjNode(CORINFO_CLASS_HANDLE structHnd, GenTree* addr)
 {
     var_types nodeType   = impNormStructType(structHnd);
     assert(varTypeIsStruct(nodeType));
-    return new (this, GT_LDOBJ) GenTreeLdObj(nodeType, addr, structHnd);
+    return new (this, GT_OBJ) GenTreeObj(nodeType, addr, structHnd);
 }
 
 // Creates a new CpObj node.
@@ -6072,9 +6069,8 @@ GenTreePtr          Compiler::gtCloneExpr(GenTree * tree,
             VarSetOps::AssignAllowUninitRhs(this, copy->gtQmark.gtElseLiveSet, tree->gtQmark.gtElseLiveSet);
             break;
 
-        case GT_LDOBJ:
-            copy = new (this, GT_LDOBJ) GenTreeLdObj(tree->TypeGet(), tree->gtOp.gtOp1, tree->gtLdObj.gtClass);
-            // Apparently, it's OK not to copy the field list when cloning.  Or at least no tests fail when we don't.
+        case GT_OBJ:
+            copy = new (this, GT_OBJ) GenTreeObj(tree->TypeGet(), tree->gtOp.gtOp1, tree->AsObj()->gtClass);
             break;
 
         case GT_BOX:
@@ -8480,7 +8476,7 @@ void                Compiler::gtDispTree(GenTreePtr             tree,
             printf(" %s <- %s", varTypeName(toType), varTypeName(fromType));
         }
 
-        if (tree->gtOper == GT_LDOBJ && (tree->gtFlags & GTF_VAR_DEATH))
+        if (tree->gtOper == GT_OBJ && (tree->gtFlags & GTF_VAR_DEATH))
         {
             printf(" (last use)");
         }
@@ -10988,19 +10984,22 @@ GenTreePtr          Compiler::gtNewTempAssign(unsigned tmp, GenTreePtr val)
     
     // With first-class structs, we should be propagating the class handle on all non-primitive
     // struct types. But we don't have a convenient way to do that for all SIMD temps.
-    if (varTypeIsStruct(valTyp) && (gtGetStructHandleIfPresent(val) != NO_CLASS_HANDLE))
+
+    CORINFO_CLASS_HANDLE structHnd = gtGetStructHandleIfPresent(val);
+    if (varTypeIsStruct(valTyp) && (structHnd != NO_CLASS_HANDLE))
     {
-        /* The GT_LDOBJ may be be a child of a GT_COMMA */
+        // The GT_OBJ may be be a child of a GT_COMMA.
         GenTreePtr valx = val->gtEffectiveVal(/*commaOnly*/true);
 
-        if (valx->gtOper == GT_LDOBJ)
+        if (valx->gtOper == GT_OBJ)
         {
-            lvaSetStruct(tmp, valx->gtLdObj.gtClass, false);
+            lvaSetStruct(tmp, structHnd, false);
         }
         dest->gtFlags |= GTF_DONT_CSE;
         valx->gtFlags |= GTF_DONT_CSE;
-        asg = impAssignStruct(dest, val, 
-                              lvaGetStruct(tmp), 
+        asg = impAssignStruct(dest,
+                              val, 
+                              structHnd, 
                               (unsigned)CHECK_SPILL_NONE);
     }
     else
@@ -11125,8 +11124,7 @@ GenTreePtr          Compiler::gtNewRefCOMfield(GenTreePtr   objPtr,
         {
             if (varTypeIsStruct(lclTyp))
             {
-                tree = new (this, GT_LDOBJ) GenTreeLdObj(lclTyp, tree, structType);
-                tree->gtLdObj.gtFldTreeList = NULL;
+                tree = gtNewObjNode(structType, tree);
             }
             else
             {
@@ -12880,7 +12878,8 @@ CORINFO_CLASS_HANDLE Compiler::gtGetStructHandleIfPresent(GenTree* tree)
         {
         default:
             break;
-        case GT_LDOBJ:      structHnd = tree->gtLdObj.gtClass;                                   break;
+        case GT_MKREFANY:   structHnd = impGetRefAnyClass();                                     break;
+        case GT_OBJ:        structHnd = tree->gtObj.gtClass;                                     break;
         case GT_CALL:       structHnd = tree->gtCall.gtRetClsHnd;                                break;
         case GT_RET_EXPR:   structHnd = tree->gtRetExpr.gtRetClsHnd;                             break;
         case GT_ARGPLACE:   structHnd = tree->gtArgPlace.gtArgPlaceClsHnd;                       break;
@@ -12892,7 +12891,9 @@ CORINFO_CLASS_HANDLE Compiler::gtGetStructHandleIfPresent(GenTree* tree)
         case GT_LCL_VAR:
         case GT_LCL_FLD:
             structHnd = lvaTable[tree->AsLclVarCommon()->gtLclNum].lvVerTypeInfo.GetClassHandle();
-            assert(structHnd != NO_CLASS_HANDLE);
+            break;
+        case GT_RETURN:
+            structHnd = gtGetStructHandleIfPresent(tree->gtOp.gtOp1);
             break;
         case GT_IND:
             if (tree->gtFlags & GTF_IND_ARR_INDEX)
@@ -12905,11 +12906,11 @@ CORINFO_CLASS_HANDLE Compiler::gtGetStructHandleIfPresent(GenTree* tree)
 #ifdef FEATURE_SIMD
             else if (varTypeIsSIMD(tree))
             {
-                structHnd = getStructHandleForSIMDType(tree->gtType);
+                structHnd = gtGetStructHandleForSIMD(tree->gtType, TYP_FLOAT);
             }
             break;
         case GT_SIMD:
-            structHnd = getStructHandleForSIMDType(tree->gtType);
+            structHnd = gtGetStructHandleForSIMD(tree->gtType, tree->AsSIMD()->gtSIMDBaseType);
 #endif // FEATURE_SIMD
             break;
         }
diff --git a/src/jit/gentree.h b/src/jit/gentree.h
index a1787f1d72..631f67b79f 100644
--- a/src/jit/gentree.h
+++ b/src/jit/gentree.h
@@ -1213,7 +1213,7 @@ public:
         case GT_COPYBLK:
         case GT_COPYOBJ:
         case GT_INITBLK:
-        case GT_LDOBJ:
+        case GT_OBJ:
         case GT_BOX:
         case GT_ARR_INDEX:
         case GT_ARR_ELEM:
@@ -2869,6 +2869,27 @@ protected:
 #endif // DEBUGGABLE_GENTREE
 };
 
+// gtObj  -- 'object' (GT_OBJ). */
+
+struct GenTreeObj: public GenTreeUnOp
+{
+    // The address of the block.
+    GenTreePtr&     Addr()          { return gtOp1; }
+
+    CORINFO_CLASS_HANDLE gtClass;   // the class of the object
+
+    GenTreeObj(var_types type, GenTreePtr addr, CORINFO_CLASS_HANDLE cls) : 
+        GenTreeUnOp(GT_OBJ, type, addr),
+        gtClass(cls)
+        {
+            gtFlags |= GTF_GLOB_REF; // An Obj is always a global reference.
+        }
+
+#if DEBUGGABLE_GENTREE
+    GenTreeObj() : GenTreeUnOp() {}
+#endif
+};
+
 // Represents a CpObj MSIL Node.
 struct GenTreeCpObj : public GenTreeBlkOp
 {
@@ -3270,24 +3291,7 @@ struct GenTreeStmt: public GenTree
 #endif
 };
 
-/* gtLdObj  -- 'push object' (GT_LDOBJ). */
 
-struct GenTreeLdObj: public GenTreeUnOp
-{
-    CORINFO_CLASS_HANDLE gtClass;   // object being loaded   
-                                    // TODO-Cleanup: Consider adding the GC layout information to this node
-    GenTreePtr *    gtFldTreeList;  // The list of trees that represents the fields of this struct
-
-    GenTreeLdObj(var_types type, GenTreePtr op, CORINFO_CLASS_HANDLE cls) : 
-        GenTreeUnOp(GT_LDOBJ, type, op),
-        gtClass(cls), gtFldTreeList(NULL)
-        {
-            gtFlags |= GTF_GLOB_REF; // A LdObj is always a global reference.
-        }
-#if DEBUGGABLE_GENTREE
-    GenTreeLdObj() : GenTreeUnOp() {}
-#endif
-};
 
 
 /*  NOTE: Any tree nodes that are larger than 8 bytes (two ints or
diff --git a/src/jit/gschecks.cpp b/src/jit/gschecks.cpp
index 90187655f7..3a80aa4f40 100644
--- a/src/jit/gschecks.cpp
+++ b/src/jit/gschecks.cpp
@@ -125,7 +125,7 @@ Compiler::fgWalkResult Compiler::gsMarkPtrsAndAssignGroups(GenTreePtr *pTree, fg
         fIsBlk = true;
         // fallthrough
     case GT_IND:
-    case GT_LDOBJ:
+    case GT_OBJ:
     case GT_ARR_ELEM:
     case GT_ARR_INDEX:
     case GT_ARR_OFFSET:
diff --git a/src/jit/gtlist.h b/src/jit/gtlist.h
index 365c8e322a..4eee84031b 100644
--- a/src/jit/gtlist.h
+++ b/src/jit/gtlist.h
@@ -73,7 +73,7 @@ GTNODE(IND              , "indir"         ,0,GTK_UNOP)          // load indirect
 GTNODE(STOREIND         , "storeIndir"    ,0,GTK_BINOP)         // store indirection
                                                                    // TODO-Cleanup: GT_ARR_BOUNDS_CHECK should be made a GTK_BINOP now that it has only two child nodes
 GTNODE(ARR_BOUNDS_CHECK , "arrBndsChk"    ,0,GTK_SPECIAL)       // array bounds check
-GTNODE(LDOBJ            , "ldobj"         ,0,GTK_UNOP|GTK_EXOP)
+GTNODE(OBJ              , "obj"           ,0,GTK_UNOP|GTK_EXOP)
 GTNODE(BOX              , "box"           ,0,GTK_UNOP|GTK_EXOP)
 
 #ifdef FEATURE_SIMD
diff --git a/src/jit/gtstructs.h b/src/jit/gtstructs.h
index d9fefbedaa..3c55c30517 100644
--- a/src/jit/gtstructs.h
+++ b/src/jit/gtstructs.h
@@ -80,7 +80,7 @@ GTSTRUCT_1(ArrOffs     , GT_ARR_OFFSET)
 GTSTRUCT_1(ArrIndex    , GT_ARR_INDEX) 
 GTSTRUCT_1(RetExpr     , GT_RET_EXPR) 
 GTSTRUCT_1(Stmt        , GT_STMT) 
-GTSTRUCT_1(LdObj       , GT_LDOBJ)
+GTSTRUCT_1(Obj         , GT_OBJ)
 GTSTRUCT_2(ClsVar      , GT_CLS_VAR, GT_CLS_VAR_ADDR) 
 GTSTRUCT_1(ArgPlace    , GT_ARGPLACE) 
 GTSTRUCT_1(Label       , GT_LABEL) 
diff --git a/src/jit/importer.cpp b/src/jit/importer.cpp
index 514c7f1083..0dbecf8ba8 100644
--- a/src/jit/importer.cpp
+++ b/src/jit/importer.cpp
@@ -588,6 +588,7 @@ inline
 void                Compiler::impAppendStmt(GenTreePtr stmt, unsigned chkLevel)
 {
     assert(stmt->gtOper == GT_STMT);
+    noway_assert(impTreeLast != nullptr);
 
     /* If the statement being appended has any side-effects, check the stack
        to see if anything needs to be spilled to preserve correct ordering. */
@@ -599,7 +600,8 @@ void                Compiler::impAppendStmt(GenTreePtr stmt, unsigned chkLevel)
        we handle them specially using impSpillLclRefs(). Temp locals should
        be fine too. */
 
-    if ((expr->gtOper == GT_ASG) && (expr->gtOp.gtOp1->gtOper == GT_LCL_VAR) &&
+    if ((expr->gtOper == GT_ASG) &&
+        (expr->gtOp.gtOp1->gtOper == GT_LCL_VAR) &&
         !(expr->gtOp.gtOp1->gtFlags & GTF_GLOB_REF) &&
         !gtHasLocalsWithAddrOp(expr->gtOp.gtOp2))
     {
@@ -872,7 +874,7 @@ GenTreeArgList*     Compiler::impPopList(unsigned   count,
 
         if (varTypeIsStruct(temp))
         {
-            // Morph trees that aren't already LDOBJs or MKREFANY to be LDOBJs
+            // Morph trees that aren't already OBJs or MKREFANY to be OBJs
             assert(ti.IsType(TI_STRUCT));
             structType = ti.GetClassHandleForValueClass();
             temp = impNormStructVal(temp, structType, (unsigned)CHECK_SPILL_ALL);
@@ -1068,11 +1070,11 @@ GenTreePtr Compiler::impAssignStruct(GenTreePtr     dest,
 
     assert(dest->gtOper == GT_LCL_VAR || dest->gtOper == GT_RETURN ||
            dest->gtOper == GT_FIELD   || dest->gtOper == GT_IND    ||
-           dest->gtOper == GT_LDOBJ);
+           dest->gtOper == GT_OBJ);
 
     GenTreePtr destAddr;
 
-    if (dest->gtOper == GT_IND || dest->gtOper == GT_LDOBJ)
+    if (dest->gtOper == GT_IND || dest->gtOper == GT_OBJ)
     {
         destAddr = dest->gtOp.gtOp1;
     }
@@ -1099,7 +1101,7 @@ GenTreePtr Compiler::impAssignStructPtr(GenTreePtr      dest,
     // TODO-ARM-BUG: Does ARM need this?
     // TODO-ARM64-BUG: Does ARM64 need this?
     assert(src->gtOper == GT_LCL_VAR  || src->gtOper == GT_FIELD    ||
-           src->gtOper == GT_IND      || src->gtOper == GT_LDOBJ    ||
+           src->gtOper == GT_IND      || src->gtOper == GT_OBJ    ||
            src->gtOper == GT_CALL     || src->gtOper == GT_MKREFANY ||
            src->gtOper == GT_RET_EXPR || src->gtOper == GT_COMMA    ||
            src->gtOper == GT_ADDR     ||
@@ -1108,7 +1110,7 @@ GenTreePtr Compiler::impAssignStructPtr(GenTreePtr      dest,
     assert(varTypeIsStruct(src));
 
     assert(src->gtOper == GT_LCL_VAR  || src->gtOper == GT_FIELD    ||
-           src->gtOper == GT_IND      || src->gtOper == GT_LDOBJ    ||
+           src->gtOper == GT_IND      || src->gtOper == GT_OBJ      ||
            src->gtOper == GT_CALL     || src->gtOper == GT_MKREFANY ||
            src->gtOper == GT_RET_EXPR || src->gtOper == GT_COMMA    ||
            (src->TypeGet() != TYP_STRUCT && (GenTree::OperIsSIMD(src->gtOper) || src->gtOper == GT_LCL_FLD)));
@@ -1197,9 +1199,9 @@ GenTreePtr Compiler::impAssignStructPtr(GenTreePtr      dest,
             return gtNewAssignNode(dest, src);
         }
     }
-    else if (src->gtOper == GT_LDOBJ)
+    else if (src->gtOper == GT_OBJ)
     {
-        assert(src->gtLdObj.gtClass == structHnd);
+        assert(src->gtObj.gtClass == structHnd);
         src = src->gtOp.gtOp1;        
     }
     else if (src->gtOper == GT_MKREFANY)
@@ -1280,14 +1282,14 @@ GenTreePtr Compiler::impGetStructAddr(GenTreePtr    structVal,
 
     genTreeOps      oper = structVal->gtOper;   
 
-    if (oper == GT_LDOBJ && willDeref)
+    if (oper == GT_OBJ && willDeref)
     {
-        assert(structVal->gtLdObj.gtClass == structHnd);
-        return(structVal->gtLdObj.gtOp1);
+        assert(structVal->gtObj.gtClass == structHnd);
+        return(structVal->gtObj.gtOp.gtOp1);
     }
-    else if (oper == GT_CALL || oper == GT_RET_EXPR || oper == GT_LDOBJ || oper == GT_MKREFANY)
+    else if (oper == GT_CALL || oper == GT_RET_EXPR || oper == GT_OBJ || oper == GT_MKREFANY)
     {
-        unsigned    tmpNum = lvaGrabTemp(true DEBUGARG("struct address for call/ldobj"));
+        unsigned    tmpNum = lvaGrabTemp(true DEBUGARG("struct address for call/obj"));
 
         impAssignTempGen(tmpNum, structVal, structHnd, curLevel);
 
@@ -1408,8 +1410,8 @@ var_types       Compiler::impNormStructType(CORINFO_CLASS_HANDLE  structHnd,
 }
 
 //****************************************************************************
-//  Given TYP_STRUCT value 'structVal', make sure it is 'canonical'
-//  is must be either a LDOBJ or a MKREFANY node 
+//  Given TYP_STRUCT value 'structVal', make sure it is 'canonical', that is
+//  it is either an OBJ or a MKREFANY node.
 //
 GenTreePtr      Compiler::impNormStructVal(GenTreePtr    structVal,
                                            CORINFO_CLASS_HANDLE  structHnd,
@@ -1447,10 +1449,6 @@ GenTreePtr      Compiler::impNormStructVal(GenTreePtr    structVal,
         structVal->gtType = structType;
         break;
 
-    case GT_IND:
-        structVal->gtType = structType;
-        break;
-
     case GT_INDEX:
         structVal->gtIndex.gtStructElemClass = structHnd;
         structVal->gtIndex.gtIndElemSize = info.compCompHnd->getClassSize(structHnd);
@@ -1465,21 +1463,24 @@ GenTreePtr      Compiler::impNormStructVal(GenTreePtr    structVal,
     case GT_LCL_FLD:
         break;
 
-    case GT_LDOBJ:
+    case GT_OBJ:
+    case GT_IND:
         // These should already have the appropriate type.
         assert(structVal->gtType == structType);
         break;
 
 #ifdef FEATURE_SIMD
     case GT_SIMD:
-        // These don't preserve the handle.
-        assert(varTypeIsSIMD(structVal));
+        assert(varTypeIsSIMD(structVal) && (structVal->gtType == structType));
         break;
 #endif // FEATURE_SIMD
 
     case GT_COMMA:
         {
+            // The second thing is the struct node.
             GenTree* op2 = structVal->gtOp.gtOp2;
+            assert(op2->gtType == structType);
+
             impNormStructVal(op2, structHnd, curLevel, forceNormalization);
             structType = op2->TypeGet();
             structVal->gtType = structType;
@@ -1492,13 +1493,13 @@ GenTreePtr      Compiler::impNormStructVal(GenTreePtr    structVal,
     }
 
     // Is it already normalized?
-    if (!forceNormalization && (structVal->gtOper == GT_MKREFANY || structVal->gtOper == GT_LDOBJ))
+    if (!forceNormalization && (structVal->gtOper == GT_MKREFANY || structVal->gtOper == GT_OBJ))
         return(structVal);
 
-    // Normalize it by wraping it in a LDOBJ
+    // Normalize it by wraping it in an OBJ
 
     GenTreePtr structAddr  = impGetStructAddr(structVal, structHnd, curLevel, !forceNormalization); // get the addr of struct
-    GenTreePtr structLdobj = new (this, GT_LDOBJ) GenTreeLdObj(structType, structAddr, structHnd);
+    GenTreePtr structObj = new (this, GT_OBJ) GenTreeObj(structType, structAddr, structHnd);
 
     if (structAddr->gtOper == GT_ADDR)
     {
@@ -1509,18 +1510,18 @@ GenTreePtr      Compiler::impNormStructVal(GenTreePtr    structVal,
     }
     if (structVal->IsLocal())
     {
-        // A LDOBJ on a ADDR(LCL_VAR) can never raise an exception
+        // A OBJ on a ADDR(LCL_VAR) can never raise an exception
         // so we don't set GTF_EXCEPT here.
         //
-        // TODO-CQ: Clear the GTF_GLOB_REF flag on structLdobj as well
+        // TODO-CQ: Clear the GTF_GLOB_REF flag on structObj as well
         //          but this needs additional work when inlining.
     }
     else  
     {
-        // In general a LDOBJ is an IND and could raise an exception
-        structLdobj->gtFlags |= GTF_EXCEPT;
+        // In general a OBJ is an IND and could raise an exception
+        structObj->gtFlags |= GTF_EXCEPT;
     }
-    return(structLdobj);
+    return(structObj);
 }
 
 
@@ -1848,7 +1849,7 @@ GenTreePtr          Compiler::impRuntimeLookupToTree(CORINFO_RUNTIME_LOOKUP_KIND
  *  Spills the stack at verCurrentState.esStack[level] and replaces it with a temp.
  *  If tnum!=BAD_VAR_NUM, the temp var used to replace the tree is tnum,
  *     else, grab a new temp.
- *  For structs (which can be pushed on the stack using ldobj, etc),
+ *  For structs (which can be pushed on the stack using obj, etc),
  *  special handling is needed
  */
 
@@ -2847,8 +2848,8 @@ GenTreePtr      Compiler::impInitializeArrayIntrinsic(CORINFO_SIG_INFO * sig)
 
     //
     // At this point we are ready to commit to implementing the InitializeArray 
-    // instrinsic using a GT_COPYBLK node.  Pop the arguments from the stack and
-    // return the GT_COPYBLK node.
+    // instrinsic using a struct assignment.  Pop the arguments from the stack and
+    // return the struct assignment node.
     //
 
     impPopStack();
@@ -4706,7 +4707,7 @@ GenTreePtr Compiler::impTransformThis (GenTreePtr thisPtr,
             GenTreePtr obj = thisPtr;
             
             assert(obj->TypeGet() == TYP_BYREF || obj->TypeGet() == TYP_I_IMPL);
-            obj = gtNewLdObjNode(pConstrainedResolvedToken->hClass, obj);
+            obj = gtNewObjNode(pConstrainedResolvedToken->hClass, obj);
             obj->gtFlags |= GTF_EXCEPT;
             
             CorInfoType jitTyp = info.compCompHnd->asCorInfoType(pConstrainedResolvedToken->hClass);
@@ -4714,7 +4715,7 @@ GenTreePtr Compiler::impTransformThis (GenTreePtr thisPtr,
             {
                 obj->ChangeOperUnchecked(GT_IND);
                 
-                // ldobj could point anywhere, example a boxed class static int
+                // Obj could point anywhere, example a boxed class static int
                 obj->gtFlags |= GTF_IND_TGTANYWHERE;
                 
                 obj->gtType = JITtype2varType(jitTyp);
@@ -5212,7 +5213,7 @@ GenTreePtr Compiler::impImportStaticFieldAccess(CORINFO_RESOLVED_TOKEN * pResolv
                 if (varTypeIsStruct(lclTyp))
                 {
                     // Constructor adds GTF_GLOB_REF.  Note that this is *not* GTF_EXCEPT.
-                    op1 = gtNewLdObjNode(pFieldInfo->structType, op1);
+                    op1 = gtNewObjNode(pFieldInfo->structType, op1);
                 }
                 else
                 {
@@ -7174,12 +7175,12 @@ REDO_RETURN_NODE:
     {
         op->ChangeOper(GT_LCL_FLD);
     }
-    else if (op->gtOper == GT_LDOBJ)
+    else if (op->gtOper == GT_OBJ)
     {
-        GenTreePtr op1 = op->gtLdObj.gtOp1;
+        GenTreePtr op1 = op->AsObj()->Addr();
 
-        // We will fold away LDOBJ/ADDR
-        // except for LDOBJ/ADDR/INDEX
+        // We will fold away OBJ/ADDR
+        // except for OBJ/ADDR/INDEX
         //     as the array type influences the array element's offset
         //     Later in this method we change op->gtType to info.compRetNativeType
         //     This is not correct when op is a GT_INDEX as the starting offset
@@ -7193,9 +7194,7 @@ REDO_RETURN_NODE:
             op = op1->gtOp.gtOp1;
             goto REDO_RETURN_NODE;
         }
-
-        op->gtLdObj.gtClass = nullptr;
-        op->gtLdObj.gtFldTreeList = nullptr;
+        op->gtObj.gtClass = NO_CLASS_HANDLE;
         op->ChangeOperUnchecked(GT_IND);
         op->gtFlags |= GTF_IND_TGTANYWHERE;
     }
@@ -7219,7 +7218,7 @@ REDO_RETURN_NODE:
             // No need to spill anything as we're about to return.
             impAssignTempGen(tmpNum, op, info.compMethodInfo->args.retTypeClass, (unsigned)CHECK_SPILL_NONE);
 
-            // Don't both creating a GT_ADDR & GT_LDOBJ jsut to undo all of that
+            // Don't create both a GT_ADDR & GT_OBJ just to undo all of that; instead,
             // jump directly to a GT_LCL_FLD.
             op = gtNewLclvNode(tmpNum, info.compRetNativeType);
             op->ChangeOper(GT_LCL_FLD);
@@ -7243,7 +7242,7 @@ REDO_RETURN_NODE:
 #endif // !FEATURE_UNIX_AMD64_STRUCT_PASSING
 #endif // DEBUG
 
-            // Don't change the gtType node just yet, it will get changed later
+            // Don't change the gtType of the node just yet, it will get changed later.
             return op;
         }
     }
@@ -8792,6 +8791,7 @@ DECODE_OPCODE:
 
             GenTreePtr      op3;
             genTreeOps      oper;
+            unsigned        size;
 
             int             val;
 
@@ -9674,14 +9674,23 @@ ARR_LD_POST_VERIFY:
 
                 // remember the element size
                 if (lclTyp == TYP_REF)
+                {
                     op1->gtIndex.gtIndElemSize = sizeof(void*);
+                }
                 else
                 {
                     // If ldElemClass is precisely a primitive type, use that, otherwise, preserve the struct type.
                     if (info.compCompHnd->getTypeForPrimitiveValueClass(ldelemClsHnd) == CORINFO_TYPE_UNDEF)
+                    {
                         op1->gtIndex.gtStructElemClass = ldelemClsHnd;
+                    }
                     assert(lclTyp != TYP_STRUCT || op1->gtIndex.gtStructElemClass != nullptr);
-                    op1->gtIndex.gtIndElemSize = info.compCompHnd->getClassSize(ldelemClsHnd);
+                    if (lclTyp == TYP_STRUCT)
+                    {
+                        size = info.compCompHnd->getClassSize(ldelemClsHnd);
+                        op1->gtIndex.gtIndElemSize = size;
+                        op1->gtType = lclTyp;
+                    }
                 }
 
                 if ((opcode == CEE_LDELEMA) || ldstruct)
@@ -9699,8 +9708,8 @@ ARR_LD_POST_VERIFY:
 
             if (ldstruct)
             {
-                // Do a LDOBJ on the result
-                op1 = gtNewLdObjNode(ldelemClsHnd, op1);
+                // Create an OBJ for the result
+                op1 = gtNewObjNode(ldelemClsHnd, op1);
                 op1->gtFlags |= GTF_EXCEPT;
             }
             impPushOnStack(op1, tiRetVal);
@@ -10708,7 +10717,7 @@ _CONV:
                 if (varTypeIsStruct(op1))
                 {                    
 #ifdef FEATURE_UNIX_AMD64_STRUCT_PASSING
-                    // Non-calls, such as ldobj or ret_expr, have to go through this.
+                    // Non-calls, such as obj or ret_expr, have to go through this.
                     // Calls with large struct return value have to go through this.
                     // Helper calls with small struct return value also have to go 
                     // through this since they do not follow Unix calling convention.
@@ -11779,7 +11788,9 @@ DO_LDFTN:
 
             /* Preserve 'small' int types */
             if  (lclTyp > TYP_INT)
+            {
                 lclTyp = genActualType(lclTyp);
+            }
 
             bool usesHelper = false;
 
@@ -11945,7 +11956,7 @@ DO_LDFTN:
 
                     if (!usesHelper)
                     {
-                        assert((op1->OperGet() == GT_FIELD) || (op1->OperGet() == GT_IND) || (op1->OperGet() == GT_LDOBJ));
+                        assert((op1->OperGet() == GT_FIELD) || (op1->OperGet() == GT_IND) || (op1->OperGet() == GT_OBJ));
                         op1->gtFlags |= GTF_IND_VOLATILE;
                     }
                 }
@@ -11954,7 +11965,7 @@ DO_LDFTN:
                 {
                     if (!usesHelper)
                     {
-                        assert((op1->OperGet() == GT_FIELD) || (op1->OperGet() == GT_IND) || (op1->OperGet() == GT_LDOBJ));
+                        assert((op1->OperGet() == GT_FIELD) || (op1->OperGet() == GT_IND) || (op1->OperGet() == GT_OBJ));
                         op1->gtFlags |= GTF_IND_UNALIGNED;
                     }
                 }
@@ -12072,8 +12083,10 @@ FIELD_DONE:
             }
 
             /* Preserve 'small' int types */
-            if  (lclTyp > TYP_INT)
+            if (lclTyp > TYP_INT)
+            {
                 lclTyp = genActualType(lclTyp);
+            }
 
             switch (fieldInfo.fieldAccessor)
             {
@@ -12462,7 +12475,7 @@ FIELD_DONE:
             // make certain it is normalized;
             op1 = impNormStructVal(op1, impGetRefAnyClass(), (unsigned)CHECK_SPILL_ALL);
 
-            if (op1->gtOper == GT_LDOBJ)
+            if (op1->gtOper == GT_OBJ)
             {
                 // Get the address of the refany
                 op1 = op1->gtOp.gtOp1;
@@ -12576,8 +12589,8 @@ FIELD_DONE:
             /* Pop the object and create the unbox helper call */
             /* You might think that for UNBOX_ANY we need to push a different */
             /* (non-byref) type, but here we're making the tiRetVal that is used */
-            /* for the intermediate pointer which we then transfer onto the LDOBJ */
-            /* instruction.  LDOBJ then creates the appropriate tiRetVal. */
+            /* for the intermediate pointer which we then transfer onto the OBJ */
+            /* instruction.  OBJ then creates the appropriate tiRetVal. */
             if (tiVerificationNeeded)
             { 
                 typeInfo tiUnbox = impStackTop().seTypeInfo;
@@ -12679,7 +12692,7 @@ FIELD_DONE:
               | UNBOX     | push the BYREF          | spill the STRUCT to a local, |
               |           |                         | push the BYREF to this local |
               |--------------------------------------------------------------------- 
-              | UNBOX_ANY | push a GT_LDOBJ of      | push the STRUCT              |
+              | UNBOX_ANY | push a GT_OBJ of        | push the STRUCT              |
               |           | the BYREF               | For Linux when the           |
               |           |                         |  struct is returned in two   |
               |           |                         |  registers create a temp     |
@@ -12720,8 +12733,8 @@ FIELD_DONE:
                 {                         
                     // Normal unbox helper returns a TYP_BYREF.
                     impPushOnStack(op1, tiRetVal);
-                    oper = GT_LDOBJ;
-                    goto LDOBJ;
+                    oper = GT_OBJ;
+                    goto OBJ;
                   }
 
                 assert(helper == CORINFO_HELP_UNBOX_NULLABLE && "Make sure the helper is nullable!");
@@ -12757,12 +12770,12 @@ FIELD_DONE:
                         impPushOnStack(op1, tiRetVal);
 
                         // Load the struct.
-                        oper = GT_LDOBJ;
+                        oper = GT_OBJ;
 
                         assert(op1->gtType == TYP_BYREF);
                         assert(!tiVerificationNeeded || tiRetVal.IsByRef());
 
-                        goto LDOBJ;
+                        goto OBJ;
                     }   
                     else
                     {
@@ -13230,14 +13243,14 @@ INITBLK_OR_INITOBJ:
 
 
         case CEE_LDOBJ: {
-            oper = GT_LDOBJ;
+            oper = GT_OBJ;
             assertImp(sz == sizeof(unsigned));
 
             _impResolveToken(CORINFO_TOKENKIND_Class);
 
             JITDUMP(" %08X", resolvedToken.token);
 
-LDOBJ:
+OBJ:
 
             tiRetVal =  verMakeTypeInfo(resolvedToken.hClass);
 
@@ -13292,9 +13305,9 @@ LDOBJ:
             }
             else
             {
-                // LDOBJ returns a struct
+                // OBJ returns a struct
                 // and an inline argument which is the class token of the loaded obj
-                op1 = gtNewLdObjNode(resolvedToken.hClass, op1);
+                op1 = gtNewObjNode(resolvedToken.hClass, op1);
             }
             op1->gtFlags |= GTF_EXCEPT;
             
diff --git a/src/jit/liveness.cpp b/src/jit/liveness.cpp
index 43eab82707..07977af79d 100644
--- a/src/jit/liveness.cpp
+++ b/src/jit/liveness.cpp
@@ -1859,13 +1859,13 @@ SKIP_QMARK:
 #ifdef LEGACY_BACKEND
         // Generally, the last use information is associated with the lclVar node.
         // However, for LEGACY_BACKEND, the information must be associated
-        // with the LDOBJ itself for promoted structs.
+        // with the OBJ itself for promoted structs.
         // In that case, the LDOBJ may be require an implementation that might itself allocate registers,
         // so the variable(s) should stay live until the end of the LDOBJ.
         // Note that for promoted structs lvTracked is false.
 
         GenTreePtr lclVarTree = nullptr;
-        if (tree->gtOper == GT_LDOBJ)
+        if (tree->gtOper == GT_OBJ)
         {
             // fgIsIndirOfAddrOfLocal returns nullptr if the tree is 
             // not an indir(addr(local)), in which case we will set lclVarTree
@@ -2208,7 +2208,7 @@ bool Compiler::fgRemoveDeadStore(GenTree** pTree, LclVarDsc* varDsc, VARSET_TP l
         }
         else if (asgNode == nullptr)
         {
-            // This may be followed by GT_IND/assign, GT_STOREIND or GT_LIST/block-op.
+            // This may be followed by GT_IND/assign or GT_STOREIND.
             if (nextNode == nullptr)
             {
                 return false;
diff --git a/src/jit/lower.cpp b/src/jit/lower.cpp
index 2d7b61f913..6e228a2f3f 100644
--- a/src/jit/lower.cpp
+++ b/src/jit/lower.cpp
@@ -1311,16 +1311,16 @@ GenTreePtr Lowering::NewPutArg(GenTreeCall* call, GenTreePtr arg, fgArgTabEntryP
         {
             unsigned numRefs = 0;
             BYTE* gcLayout = new (comp, CMK_Codegen) BYTE[fp->numSlots];
-            // We use GT_LDOBJ for non-SIMD struct arguments. However, for
-            // SIMD arguments the GT_LDOBJ has already been transformed.
-            if (arg->gtOper != GT_LDOBJ)
+            // We use GT_OBJ for non-SIMD struct arguments. However, for
+            // SIMD arguments the GT_OBJ has already been transformed.
+            if (arg->gtOper != GT_OBJ)
             {
                 assert(varTypeIsSIMD(arg));
             }
             else
             {
                 assert(!varTypeIsSIMD(arg));
-                numRefs = comp->info.compCompHnd->getClassGClayout(arg->gtLdObj.gtClass, gcLayout);
+                numRefs = comp->info.compCompHnd->getClassGClayout(arg->gtObj.gtClass, gcLayout);
             }
 
             putArg->AsPutArgStk()->setGcPointers(numRefs, gcLayout);
diff --git a/src/jit/lowerarm64.cpp b/src/jit/lowerarm64.cpp
index c51f7b052e..71bfc23632 100644
--- a/src/jit/lowerarm64.cpp
+++ b/src/jit/lowerarm64.cpp
@@ -623,10 +623,10 @@ void Lowering::TreeNodeInfoInit(GenTree* stmt)
                         {
                             originalSize = 2 * TARGET_POINTER_SIZE;
                         }
-                        else if (actualArgNode->gtOper == GT_LDOBJ)
+                        else if (actualArgNode->gtOper == GT_OBJ)
                         {
-                            CORINFO_CLASS_HANDLE ldObjClass = actualArgNode->gtLdObj.gtClass;
-                            originalSize = compiler->info.compCompHnd->getClassSize(ldObjClass);
+                            CORINFO_CLASS_HANDLE objClass = actualArgNode->gtObj.gtClass;
+                            originalSize = compiler->info.compCompHnd->getClassSize(objClass);
                         }
                         else
                         {
diff --git a/src/jit/lowerxarch.cpp b/src/jit/lowerxarch.cpp
index c9ea7d18b1..4103b843b0 100644
--- a/src/jit/lowerxarch.cpp
+++ b/src/jit/lowerxarch.cpp
@@ -948,12 +948,12 @@ void Lowering::TreeNodeInfoInit(GenTree* stmt)
 #ifdef FEATURE_UNIX_AMD64_STRUCT_PASSING
                     // If the node is TYP_STRUCT and it is put on stack with
                     // putarg_stk operation, we consume and produce no registers.
-                    // In this case the embedded LdObj node should not produce 
+                    // In this case the embedded Obj node should not produce 
                     // registers too since it is contained.
                     // Note that if it is a SIMD type the argument will be in a register.
                     if (argNode->TypeGet() == TYP_STRUCT)
                     {
-                        assert(argNode->gtOp.gtOp1 != nullptr && argNode->gtOp.gtOp1->OperGet() == GT_LDOBJ);
+                        assert(argNode->gtOp.gtOp1 != nullptr && argNode->gtOp.gtOp1->OperGet() == GT_OBJ);
                         argNode->gtOp.gtOp1->gtLsraInfo.dstCount = 0;
                         argNode->gtLsraInfo.srcCount = 0;
                     }
@@ -1001,9 +1001,9 @@ void Lowering::TreeNodeInfoInit(GenTree* stmt)
                     {
                         originalSize = 2 * TARGET_POINTER_SIZE;
                     }
-                    else if (argNode->gtOper == GT_LDOBJ)
+                    else if (argNode->gtOper == GT_OBJ)
                     {
-                        noway_assert(!"GT_LDOBJ not supported for amd64");
+                        noway_assert(!"GT_OBJ not supported for amd64");
                     }
 #ifdef FEATURE_UNIX_AMD64_STRUCT_PASSING
                     else if (argNode->gtOper == GT_PUTARG_REG)
@@ -1200,8 +1200,8 @@ void Lowering::TreeNodeInfoInit(GenTree* stmt)
         }
         break;
 #ifdef _TARGET_X86_
-        case GT_LDOBJ:
-            NYI_X86("GT_LDOBJ");
+        case GT_OBJ:
+            NYI_X86("GT_OBJ");
 #endif //_TARGET_X86_
 
         case GT_INITBLK:
@@ -1226,7 +1226,7 @@ void Lowering::TreeNodeInfoInit(GenTree* stmt)
             GenTreePtr   src = tree->gtOp.gtOp1;
             GenTreePtr   srcAddr = nullptr;
 
-            if ((src->OperGet() == GT_LDOBJ) || (src->OperGet() == GT_IND))
+            if ((src->OperGet() == GT_OBJ) || (src->OperGet() == GT_IND))
             {
                 srcAddr = src->gtOp.gtOp1;
             }
@@ -1317,7 +1317,7 @@ void Lowering::TreeNodeInfoInit(GenTree* stmt)
                 putArgStkTree->gtPutArgStkKind = GenTreePutArgStk::PutArgStkKindRepInstr;
             }
             
-            // Always mark the LDOBJ and ADDR as contained trees by the putarg_stk. The codegen will deal with this tree.
+            // Always mark the OBJ and ADDR as contained trees by the putarg_stk. The codegen will deal with this tree.
             MakeSrcContained(putArgStkTree, src);
             
             // Balance up the inc above.
diff --git a/src/jit/morph.cpp b/src/jit/morph.cpp
index fb9585a38c..fa2b486df0 100644
--- a/src/jit/morph.cpp
+++ b/src/jit/morph.cpp
@@ -2058,13 +2058,13 @@ GenTreePtr    Compiler::fgMakeTmpArgNode(unsigned tmpVarNum
             {
                 // ToDo-ARM64: Consider using:  arg->ChangeOper(GT_LCL_FLD);
                 // as that is how FEATURE_UNIX_AMD64_STRUCT_PASSING works.
-                // Create a GT_LDOBJ for the argument 
+                // Create a GT_OBJ for the argument 
                 // This will be passed by value in two registers
                 arg = gtNewOperNode(GT_ADDR, TYP_BYREF, arg);
                 addrNode = arg;
 
-                // Ldobj the temp to use it as a call argument
-                arg = gtNewLdObjNode(lvaGetStruct(tmpVarNum), arg);
+                // Create an Obj of the temp to use it as a call argument.
+                arg = gtNewObjNode(lvaGetStruct(tmpVarNum), arg);
             }
             else
 #endif // _TARGET_ARM64_
@@ -2089,8 +2089,8 @@ GenTreePtr    Compiler::fgMakeTmpArgNode(unsigned tmpVarNum
         arg = gtNewOperNode(GT_ADDR, TYP_BYREF, arg);
         addrNode = arg;
 
-        // Ldobj the temp to use it as a call argument
-        arg = gtNewLdObjNode(lvaGetStruct(tmpVarNum), arg);
+        // Get a new Obj node temp to use it as a call argument
+        arg = gtNewObjNode(lvaGetStruct(tmpVarNum), arg);
         arg->gtFlags |= GTF_EXCEPT;
 
 #endif  // not (_TARGET_AMD64_ or _TARGET_ARM64_)
@@ -2303,25 +2303,25 @@ void fgArgInfo::EvalArgsToTemps()
                 // Need a temp to walk any GT_COMMA nodes when searching for the clsHnd
                 GenTreePtr  defArgTmp = defArg;
 
-                /* The GT_LDOBJ may be be a child of a GT_COMMA */
+                // The GT_OBJ may be be a child of a GT_COMMA.
                 while (defArgTmp->gtOper == GT_COMMA)
                 {
                     defArgTmp = defArgTmp->gtOp.gtOp2;
                 }
                 assert(varTypeIsStruct(defArgTmp));
 
-                /* We handle two opcodes: GT_MKREFANY and GT_LDOBJ */
+                // We handle two opcodes: GT_MKREFANY and GT_OBJ.
                 if (defArgTmp->gtOper == GT_MKREFANY)
                 {
                     clsHnd = compiler->impGetRefAnyClass();
                 }
-                else if (defArgTmp->gtOper == GT_LDOBJ)
+                else if (defArgTmp->gtOper == GT_OBJ)
                 {
-                    clsHnd = defArgTmp->gtLdObj.gtClass;
+                    clsHnd = defArgTmp->AsObj()->gtClass;
                 }
                 else
                 {
-                    BADCODE("Unhandled TYP_STRUCT argument tree in fgMorphArgs");
+                    BADCODE("Unhandled struct argument tree in fgMorphArgs");
                 }
         }
 
@@ -3153,7 +3153,7 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
 #endif
             else // struct type
             {
-                /* We handle two opcodes: GT_MKREFANY and GT_LDOBJ */
+                // We handle two opcodes: GT_MKREFANY and GT_OBJ
                 if (argx->gtOper == GT_MKREFANY)
                 {
                     if (varTypeIsStruct(argx))
@@ -3178,30 +3178,31 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
                     size = 2;
 #endif
                 }
-                else // (argx->gtOper == GT_LDOBJ)
+                else
                 {
-                    GenTreePtr   argLdobj         = argx;
-                    GenTreePtr*  parentOfArgLdobj = parentArgx;
+                    // GT_OBJ case
+                    GenTreePtr   argObj         = argx;
+                    GenTreePtr*  parentOfArgObj = parentArgx;
 
                     assert(args->IsList());
                     assert(argx == args->Current());
 
-                    /* The GT_LDOBJ may be be a child of a GT_COMMA */
-                    while (argLdobj->gtOper == GT_COMMA)
+                    /* The GT_OBJ may be be a child of a GT_COMMA */
+                    while (argObj->gtOper == GT_COMMA)
                     {
-                        parentOfArgLdobj = &argLdobj->gtOp.gtOp2;
-                        argLdobj         = argLdobj->gtOp.gtOp2;
+                        parentOfArgObj = &argObj->gtOp.gtOp2;
+                        argObj         = argObj->gtOp.gtOp2;
                     }
 
-                    if (argLdobj->gtOper != GT_LDOBJ)
+                    if (argObj->gtOper != GT_OBJ)
                         BADCODE("illegal argument tree in fgMorphArgs");
 
-                    CORINFO_CLASS_HANDLE ldObjClass = argLdobj->gtLdObj.gtClass;
+                    CORINFO_CLASS_HANDLE objClass = argObj->gtObj.gtClass;
 #ifdef FEATURE_UNIX_AMD64_STRUCT_PASSING
-                    eeGetSystemVAmd64PassStructInRegisterDescriptor(ldObjClass, &structDesc);
+                    eeGetSystemVAmd64PassStructInRegisterDescriptor(objClass, &structDesc);
 #endif // FEATURE_UNIX_AMD64_STRUCT_PASSING
 
-                    unsigned originalSize = info.compCompHnd->getClassSize(ldObjClass);
+                    unsigned originalSize = info.compCompHnd->getClassSize(objClass);
                     originalSize = (originalSize == 0 ? TARGET_POINTER_SIZE : originalSize);
                     unsigned roundupSize  = (unsigned)roundUp(originalSize, TARGET_POINTER_SIZE);
 #ifdef FEATURE_UNIX_AMD64_STRUCT_PASSING
@@ -3226,7 +3227,7 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
 #ifndef FEATURE_UNIX_AMD64_STRUCT_PASSING
                         size = 1;      // This must be copied to a temp and passed by address
                         passStructByRef = true;
-                        copyBlkClass = ldObjClass;
+                        copyBlkClass = objClass;
 #else // FEATURE_UNIX_AMD64_STRUCT_PASSING
                         if (!structDesc.passedInRegisters)
                         {
@@ -3235,9 +3236,9 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
                         }
                         else
                         {
-                            // The ldObjClass is used to materialize the struct on stack.
+                            // The objClass is used to materialize the struct on stack.
                             passStructInRegisters = true;
-                            copyBlkClass = ldObjClass;
+                            copyBlkClass = objClass;
                         }
 #endif // FEATURE_UNIX_AMD64_STRUCT_PASSING
 #elif defined(_TARGET_ARM64_)
@@ -3245,20 +3246,20 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
                         {
                             size = 1;      // This must be copied to a temp and passed by address
                             passStructByRef = true;
-                            copyBlkClass = ldObjClass;
+                            copyBlkClass = objClass;
                         }
 #endif
 
 #ifdef _TARGET_ARM_
                         // If we're passing a promoted struct local var, 
                         // we may need to skip some registers due to alignment; record those.
-                        GenTreePtr lclVar = fgIsIndirOfAddrOfLocal(argLdobj);
+                        GenTreePtr lclVar = fgIsIndirOfAddrOfLocal(argObj);
                         if (lclVar != NULL)
                         {
                             LclVarDsc*  varDsc = &lvaTable[lclVar->gtLclVarCommon.gtLclNum];
                             if (varDsc->lvPromoted)
                             {
-                                assert(argLdobj->OperGet() == GT_LDOBJ);
+                                assert(argObj->OperGet() == GT_OBJ);
                                 if (lvaGetPromotionType(varDsc) == PROMOTION_TYPE_INDEPENDENT)
                                 {
                                     fgAddSkippedRegsInPromotedStructArg(varDsc, intArgRegNum, &argSkippedRegMask);
@@ -3270,35 +3271,35 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
 #ifndef FEATURE_UNIX_AMD64_STRUCT_PASSING
                     else 
                     {
-                        // change our GT_LDOBJ into a GT_IND of the correct type.
-                        structBaseType = argOrReturnTypeForStruct(originalSize, argLdobj->gtLdObj.gtClass, false /* forReturn */);
+                        // change our GT_OBJ into a GT_IND of the correct type.
+                        structBaseType = argOrReturnTypeForStruct(originalSize, objClass, false /* forReturn */);
                         // We've already ensured above that size is a power of 2, and less than pointer size.
                         noway_assert(structBaseType != TYP_UNKNOWN);
 
-                        argLdobj->ChangeOper(GT_IND);
+                        argObj->ChangeOper(GT_IND);
 
                         // Now see if we can fold *(&X) into X
-                        if (argLdobj->gtOp.gtOp1->gtOper == GT_ADDR)
+                        if (argObj->gtOp.gtOp1->gtOper == GT_ADDR)
                         {
-                            GenTreePtr temp = argLdobj->gtOp.gtOp1->gtOp.gtOp1;
+                            GenTreePtr temp = argObj->gtOp.gtOp1->gtOp.gtOp1;
 
                             // Keep the DONT_CSE flag in sync
                             // (as the addr always marks it for its op1)
                             temp->gtFlags &= ~GTF_DONT_CSE;
-                            temp->gtFlags |= (argLdobj->gtFlags & GTF_DONT_CSE);
-                            DEBUG_DESTROY_NODE(argLdobj->gtOp.gtOp1);   // GT_ADDR
-                            DEBUG_DESTROY_NODE(argLdobj);               // GT_IND
+                            temp->gtFlags |= (argObj->gtFlags & GTF_DONT_CSE);
+                            DEBUG_DESTROY_NODE(argObj->gtOp.gtOp1);   // GT_ADDR
+                            DEBUG_DESTROY_NODE(argObj);               // GT_IND
 
-                            argLdobj = temp;
-                            *parentOfArgLdobj = temp;
+                            argObj = temp;
+                            *parentOfArgObj = temp;
 
-                            // If the LDOBJ had been the top level node, we've now changed argx.
-                            if (parentOfArgLdobj == parentArgx)
+                            // If the OBJ had been the top level node, we've now changed argx.
+                            if (parentOfArgObj == parentArgx)
                                 argx = temp;
                         }
-                        if (argLdobj->gtOper == GT_LCL_VAR)
+                        if (argObj->gtOper == GT_LCL_VAR)
                         {
-                            unsigned lclNum = argLdobj->gtLclVarCommon.gtLclNum;
+                            unsigned lclNum = argObj->gtLclVarCommon.gtLclNum;
                             LclVarDsc *  varDsc = &lvaTable[lclNum];
 
                             if (varDsc->lvPromoted)
@@ -3310,36 +3311,36 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
                                     if (genTypeSize(fieldVarDsc->TypeGet()) >= originalSize)
                                     {
                                         // we will use the first and only promoted field
-                                        argLdobj->gtLclVarCommon.SetLclNum(varDsc->lvFieldLclStart);
+                                        argObj->gtLclVarCommon.SetLclNum(varDsc->lvFieldLclStart);
 
                                         if (varTypeCanReg(fieldVarDsc->TypeGet()) && (genTypeSize(fieldVarDsc->TypeGet()) == originalSize))
                                         {
                                             // Just use the existing field's type
-                                            argLdobj->gtType = fieldVarDsc->TypeGet();
+                                            argObj->gtType = fieldVarDsc->TypeGet();
                                         }
                                         else 
                                         {
                                             // Can't use the existing field's type, so use GT_LCL_FLD to swizzle
                                             // to a new type
-                                            argLdobj->ChangeOper(GT_LCL_FLD);
-                                            argLdobj->gtType = structBaseType;
+                                            argObj->ChangeOper(GT_LCL_FLD);
+                                            argObj->gtType = structBaseType;
                                         }
-                                        assert(varTypeCanReg(argLdobj->TypeGet()));
+                                        assert(varTypeCanReg(argObj->TypeGet()));
                                         assert(copyBlkClass == NO_CLASS_HANDLE);
                                     }
                                     else
                                     {
                                         // use GT_LCL_FLD to swizzle the single field struct to a new type
                                         lvaSetVarDoNotEnregister(lclNum DEBUG_ARG(DNER_LocalField));
-                                        argLdobj->ChangeOper(GT_LCL_FLD);
-                                        argLdobj->gtType = structBaseType;
+                                        argObj->ChangeOper(GT_LCL_FLD);
+                                        argObj->gtType = structBaseType;
                                     }
                                 }
                                 else
                                 {
                                     // The struct fits into a single register, but it has been promoted into its
                                     // constituent fields, and so we have to re-assemble it
-                                    copyBlkClass = ldObjClass;
+                                    copyBlkClass = objClass;
 #ifdef _TARGET_ARM_
                                     // Alignment constraints may cause us not to use (to "skip") some argument registers.
                                     // Add those, if any, to the skipped (int) arg reg mask.
@@ -3350,16 +3351,16 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
                             else if (!varTypeIsIntegralOrI(varDsc->TypeGet()))
                             {
                                 // Not a promoted struct, so just swizzle the type by using GT_LCL_FLD
-                                argLdobj->ChangeOper(GT_LCL_FLD);
-                                argLdobj->gtType = structBaseType;
+                                argObj->ChangeOper(GT_LCL_FLD);
+                                argObj->gtType = structBaseType;
                             }
                         }
                         else
                         {
                             // Not a GT_LCL_VAR, so we can just change the type on the node
-                            argLdobj->gtType = structBaseType;
+                            argObj->gtType = structBaseType;
                         }
-                        assert(varTypeCanReg(argLdobj->TypeGet()) ||
+                        assert(varTypeCanReg(argObj->TypeGet()) ||
                                ((copyBlkClass != NO_CLASS_HANDLE) && varTypeIsIntegral(structBaseType)));
 
                         size = 1;
@@ -3367,7 +3368,7 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
 #endif // FEATURE_UNIX_AMD64_STRUCT_PASSING
 
 #endif // not _TARGET_X86_
-                    // We still have a struct unless we converted the GT_LDOBJ into a GT_IND above...
+                    // We still have a struct unless we converted the GT_OBJ into a GT_IND above...
                     if ((structBaseType == TYP_STRUCT) &&
 #if defined(FEATURE_UNIX_AMD64_STRUCT_PASSING)
                         !passStructInRegisters
@@ -3377,30 +3378,30 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
                         )
                     {
                         // if the valuetype size is not a multiple of sizeof(void*),
-                        // we must copyblk to a temp before doing the ldobj to avoid
-                        // the ldobj reading memory past the end of the valuetype
+                        // we must copyblk to a temp before doing the obj to avoid
+                        // the obj reading memory past the end of the valuetype
 #if defined(_TARGET_X86_) && !defined(LEGACY_BACKEND)
                         // TODO-X86-CQ: [1091733] Revisit for small structs, we should use push instruction
-                        copyBlkClass = ldObjClass;
+                        copyBlkClass = objClass;
                         size = roundupSize / TARGET_POINTER_SIZE;   // Normalize size to number of pointer sized items
 #else // !defined(_TARGET_X86_) || defined(LEGACY_BACKEND)
                         if (roundupSize > originalSize)
                         {
-                            copyBlkClass = ldObjClass;
+                            copyBlkClass = objClass;
 
                             // There are a few special cases where we can omit using a CopyBlk
                             // where we normally would need to use one.
 
-                            GenTreePtr  ldObjOp1 = argLdobj->gtLdObj.gtOp1;
-                            if (ldObjOp1->gtOper == GT_ADDR)
+                            GenTreePtr  objAddr = argObj->gtObj.gtOp1;
+                            if (objAddr->gtOper == GT_ADDR)
                             {
                                 // exception : no need to use CopyBlk if the valuetype is on the stack
-                                if (ldObjOp1->gtFlags & GTF_ADDR_ONSTACK)
+                                if (objAddr->gtFlags & GTF_ADDR_ONSTACK)
                                 {
                                     copyBlkClass = NO_CLASS_HANDLE;
                                 }
                                 // exception : no need to use CopyBlk if the valuetype is already a struct local
-                                else if (ldObjOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
+                                else if (objAddr->gtOp.gtOp1->gtOper == GT_LCL_VAR)
                                 {
                                     copyBlkClass = NO_CLASS_HANDLE;
                                 }
@@ -3846,7 +3847,9 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* callNode)
         }
         else
 #endif // FEATURE_UNIX_AMD64_STRUCT_PASSING
+        {
             argSlots += size;
+        }
     } // end foreach argument loop
 
     if  (!lateArgsComputed)
@@ -4046,8 +4049,8 @@ void Compiler::fgMorphSystemVStructArgs(GenTreeCall* call, bool hasStructArgumen
                     continue;
                 }
 
-                // If already LDOBJ it is set properly already.
-                if (arg->OperGet() == GT_LDOBJ)
+                // If already OBJ it is set properly already.
+                if (arg->OperGet() == GT_OBJ)
                 {
                     assert(!fgEntryPtr->structDesc.passedInRegisters);
                     continue;
@@ -4119,8 +4122,8 @@ void Compiler::fgMorphSystemVStructArgs(GenTreeCall* call, bool hasStructArgumen
 
                         assert(arg->OperGet() == GT_ADDR || arg->OperGet() == GT_LCL_VAR_ADDR);
 
-                        // Ldobj the temp to use it as a call argument
-                        arg = new (this, GT_LDOBJ) GenTreeLdObj(originalType, arg, lvaGetStruct(lclCommon->gtLclNum));
+                        // Create an Obj of the temp to use it as a call argument.
+                        arg = new (this, GT_OBJ) GenTreeObj(originalType, arg, lvaGetStruct(lclCommon->gtLclNum));
                         arg->gtFlags |= GTF_EXCEPT;
                         flagsSummary |= GTF_EXCEPT;
                     }
@@ -4184,7 +4187,7 @@ Compiler::fgMakeOutgoingStructArgCopy(GenTreeCall* call,
     // See if we need to insert a copy at all
     // Case 1: don't need a copy if it is the last use of a local.  We can't determine that all of the time
     // but if there is only one use and no loops, the use must be last.
-    if (argx->gtOper == GT_LDOBJ)
+    if (argx->gtOper == GT_OBJ)
     {
         GenTree* lcl = argx->gtOp.gtOp1;
         if (lcl->OperIsLocal())
@@ -4264,7 +4267,7 @@ Compiler::fgMakeOutgoingStructArgCopy(GenTreeCall* call,
     lvaTable[tmp].incRefCnts(compCurBB->getBBWeight(this), this);
 
     GenTreePtr  src;
-    if (argx->gtOper == GT_LDOBJ)
+    if (argx->gtOper == GT_OBJ)
     {
         src = argx->gtOp.gtOp1;
     }
@@ -5207,7 +5210,7 @@ GenTreePtr          Compiler::fgMorphField(GenTreePtr tree, MorphAddrContext* ma
             We want to make it like this (when fldOffset is <= MAX_UNCHECKED_OFFSET_FOR_NULL_OBJECT):
 
                                   +--------------------+
-                                  |       GT_IND       |   tree
+                                  |   GT_IND/GT_OBJ    |   tree
                                   +---------+----------+
                                             |
                                             |
@@ -5228,7 +5231,7 @@ GenTreePtr          Compiler::fgMorphField(GenTreePtr tree, MorphAddrContext* ma
 
 
                                   +--------------------+
-                                  |       GT_IND       |  tree
+                                  |   GT_IND/GT_OBJ    |   tree
                                   +----------+---------+
                                              |
                                   +----------+---------+
@@ -5835,20 +5838,19 @@ bool                Compiler::fgCanFastTailCall(GenTreeCall* callee)
 
         if (varTypeIsStruct(argx))
         {
-            // GT_LDOBJ may be a chile of a GT_COMMA. Skip over comma opers.
+            // Actual arg may be a child of a GT_COMMA. Skip over comma opers.
             while (argx->gtOper == GT_COMMA)
             {
                 argx = argx->gtOp.gtOp2;
             }
 
-            // Get the size of the struct and see if it is 1, 2, 4 or 8 bytes in size
-            // For Amd64-Unix the call below checks to see if the struct is register passable.
-            if (argx->OperGet() == GT_LDOBJ)
+            // Get the size of the struct and see if it is register passable.
+            if (argx->OperGet() == GT_OBJ)
             {
 #ifdef _TARGET_AMD64_
 
                 unsigned typeSize = 0;
-                hasMultiByteArgs = !VarTypeIsMultiByteAndCanEnreg(argx->TypeGet(), argx->gtLdObj.gtClass, &typeSize, false);
+                hasMultiByteArgs = !VarTypeIsMultiByteAndCanEnreg(argx->TypeGet(), argx->gtObj.gtClass, &typeSize, false);
 
 #if defined(FEATURE_UNIX_AMD64_STRUCT_PASSING)
                 // On System V the args could be a 2 eightbyte struct that is passed in two registers.
@@ -7954,7 +7956,7 @@ GenTreePtr          Compiler::fgMorphCopyBlock(GenTreePtr tree)
             }
         }
 
-        // Check to see if we a required to do a copy block because the struct contains holes
+        // Check to see if we are required to do a copy block because the struct contains holes
         // and either the src or dest is externally visible
         //
         bool  requiresCopyBlock = false;
@@ -9514,7 +9516,7 @@ NO_MUL_64RSLT:
                 break;
             case GT_IND:
             case GT_INITBLK:
-            case GT_LDOBJ:
+            case GT_OBJ:
                 subMac1 = &subIndMac1;
                 break;
             default:
@@ -15642,10 +15644,17 @@ bool Compiler::fgMorphImplicitByRefArgs(GenTreePtr tree, fgWalkData* fgWalkPre)
     else
     {
         // Change X into *X
+        // First, save the original type, then change the tree type to TYP_BYREF (otherwise we
+        // will get an assert when we try to clone the lclVar node because the lclVar is now TYP_BYREF
+        // and the types have to match). The reason we clone the lclVar is that we don't pass a
+        // possible-modified tree back to the caller, so we modify the original lclVar node in-place
+        // to the GT_IND.
         var_types structType = tree->gtType;
         lclVarTree = gtClone(tree);
+        // Now, set the types appropriately.
         lclVarTree->gtType = TYP_BYREF;
         tree->gtType = structType;
+        // Now, "insert" the GT_IND by changing the oper of the original node and setting its op1.
         tree->SetOper(GT_IND);
         tree->gtOp.gtOp1 = lclVarTree;
         // TODO-CQ: If the VM ever stops violating the ABI and passing heap references
@@ -15823,7 +15832,7 @@ Compiler::fgWalkResult      Compiler::fgMarkAddrTakenLocalsPreCB(GenTreePtr* pTr
     switch (tree->gtOper)
     {
     case GT_IND:
-    case GT_LDOBJ:
+    case GT_OBJ:
         if (axc != AXC_Addr)
         {
             axcStack->Push(AXC_Ind);
diff --git a/src/jit/rationalize.cpp b/src/jit/rationalize.cpp
index f7fad3e424..2eebb9804e 100644
--- a/src/jit/rationalize.cpp
+++ b/src/jit/rationalize.cpp
@@ -1538,10 +1538,10 @@ void Rationalizer::RewriteCopyBlk(GenTreePtr* ppTree, Compiler::fgWalkData* data
 #endif // FEATURE_SIMD
 }
 
-// Rewrite GT_LDOBJ of SIMD Vector as GT_IND(GT_LEA(ldobj.op1)) of a SIMD type.
+// Rewrite GT_OBJ of SIMD Vector as GT_IND(GT_LEA(obj.op1)) of a SIMD type.
 //
 // Arguments:
-//    ppTree      - A pointer-to-a-pointer for the GT_LDOBJ
+//    ppTree      - A pointer-to-a-pointer for the GT_OBJ
 //    fgWalkData  - A pointer to tree walk data providing the context
 //
 // Return Value:
@@ -1550,16 +1550,16 @@ void Rationalizer::RewriteCopyBlk(GenTreePtr* ppTree, Compiler::fgWalkData* data
 // TODO-Cleanup: Once SIMD types are plumbed through the frontend, this will no longer
 // be required.
 //
-void Rationalizer::RewriteLdObj(GenTreePtr* ppTree, Compiler::fgWalkData* data)
+void Rationalizer::RewriteObj(GenTreePtr* ppTree, Compiler::fgWalkData* data)
 {    
 #ifdef FEATURE_SIMD
     Compiler* comp = data->compiler;
-    GenTreeLdObj* ldObj = (*ppTree)->AsLdObj();
+    GenTreeObj* obj = (*ppTree)->AsObj();
 
-    // For UNIX struct passing, we can have LdObj nodes for arguments.
+    // For UNIX struct passing, we can have Obj nodes for arguments.
     // For other cases, we should never see a non-SIMD type here.
 #ifdef FEATURE_UNIX_AMD64_STRUCT_PASSING
-    if (!varTypeIsSIMD(ldObj))
+    if (!varTypeIsSIMD(obj))
     {
         return;
     }
@@ -1567,49 +1567,49 @@ void Rationalizer::RewriteLdObj(GenTreePtr* ppTree, Compiler::fgWalkData* data)
     // Should come here only if featureSIMD is enabled
     noway_assert(comp->featureSIMD);
     // On  we should only call this with a SIMD type.
-    noway_assert(varTypeIsSIMD(ldObj));
-    var_types simdType = ldObj->TypeGet();
+    noway_assert(varTypeIsSIMD(obj));
+    var_types simdType = obj->TypeGet();
 
-    // If the operand of ldobj is a GT_ADDR(GT_LCL_VAR) and LclVar is known to be a SIMD type,
-    // replace ldobj by GT_LCL_VAR.
-    GenTree* srcAddr = ldObj->gtGetOp1();
+    // If the operand of obj is a GT_ADDR(GT_LCL_VAR) and LclVar is known to be a SIMD type,
+    // replace obj by GT_LCL_VAR.
+    GenTree* srcAddr = obj->gtGetOp1();
     if (srcAddr->OperGet() == GT_ADDR && comp->isSIMDTypeLocal(srcAddr->gtGetOp1()))
     {
         GenTree* src = srcAddr->gtGetOp1();
         comp->fgSnipInnerNode(srcAddr);
-        // It is possible for the ldobj to be the last node in the tree, if its result is
+        // It is possible for the obj to be the last node in the tree, if its result is
         // not actually stored anywhere and is not eliminated.
         // This can happen with an unused SIMD expression involving a localVar or temporary value,
         // where the SIMD expression is returning a non-SIMD value, and the expression is sufficiently
         // complex (e.g. a call to vector * scalar which is inlined but not an intrinsic).
-        // The ldobj of the localVar is not eliminated, because it involves an indirection,
-        // and therefore appears potentially unsafe to eliminate. However, when we transform the ldobj into
+        // The obj of the localVar is not eliminated, because it involves an indirection,
+        // and therefore appears potentially unsafe to eliminate. However, when we transform the obj into
         // a plain localVar during the Rationalizer, we need to correctly handle the case where it has
         // no parent.
         // This happens, for example, with this source code:
         //      Vector4.Dot(default(Vector4) * 2f, Vector4.One);
-        if (ldObj->gtNext == nullptr)
+        if (obj->gtNext == nullptr)
         {
             SplitData *tmpState = (SplitData *) data->pCallbackData;
-            comp->fgSnipNode(tmpState->root->AsStmt(), ldObj);
+            comp->fgSnipNode(tmpState->root->AsStmt(), obj);
         }
         else
         {
-            comp->fgSnipInnerNode(ldObj);
+            comp->fgSnipInnerNode(obj);
         }
-        comp->fgFixupIfCallArg(data->parentStack, ldObj, src);
+        comp->fgFixupIfCallArg(data->parentStack, obj, src);
         src->gtType = simdType;
 
         *ppTree = src;
     }
     else 
     {
-        ldObj->SetOper(GT_IND);
-        ldObj->gtType = simdType;
+        obj->SetOper(GT_IND);
+        obj->gtType = simdType;
     }
 #else
     // we should never reach without feature SIMD
-    assert(!"Unexpected Ldobj during rationalization\n");
+    assert(!"Unexpected obj during rationalization\n");
     unreached();
 #endif
 }
@@ -1979,8 +1979,8 @@ Compiler::fgWalkResult Rationalizer::SimpleTransformHelper(GenTree **ppTree, Com
             RewriteCopyBlk(ppTree, data);
             break;
 
-        case GT_LDOBJ:
-            RewriteLdObj(ppTree, data);
+        case GT_OBJ:
+            RewriteObj(ppTree, data);
             break;
 
         case GT_LCL_FLD:
diff --git a/src/jit/rationalize.h b/src/jit/rationalize.h
index f5e142e596..90f39c32d0 100644
--- a/src/jit/rationalize.h
+++ b/src/jit/rationalize.h
@@ -168,7 +168,7 @@ private:
     bool       BreakFirstLevelQuestions (BasicBlock* block, GenTree* tree);
     
     // SIMD related transformations
-    static void RewriteLdObj(GenTreePtr* ppTree, Compiler::fgWalkData* data);
+    static void RewriteObj(GenTreePtr* ppTree, Compiler::fgWalkData* data);
     static void RewriteCopyBlk(GenTreePtr* ppTree, Compiler::fgWalkData* data);
     static void RewriteInitBlk(GenTreePtr* ppTree, Compiler::fgWalkData* data);
 
diff --git a/src/jit/regalloc.cpp b/src/jit/regalloc.cpp
index 739478c3f7..1675f2c018 100644
--- a/src/jit/regalloc.cpp
+++ b/src/jit/regalloc.cpp
@@ -4311,7 +4311,7 @@ HANDLE_SHIFT_COUNT:
             goto RETURN_CHECK;
         }
 
-        case GT_LDOBJ:
+        case GT_OBJ:
             {
 #ifdef _TARGET_ARM_
                 if (predictReg <= PREDICT_REG)
@@ -4328,16 +4328,16 @@ HANDLE_SHIFT_COUNT:
                 }
 
 #ifdef _TARGET_ARM_
-                unsigned objSize = info.compCompHnd->getClassSize(tree->gtLdObj.gtClass);
+                unsigned objSize = info.compCompHnd->getClassSize(tree->gtObj.gtClass);
                 regMaskTP preferReg = rpPredictRegMask(predictReg, TYP_I_IMPL);
                 // If it has one bit set, and that's an arg reg...
                 if (preferReg != RBM_NONE && genMaxOneBit(preferReg) && ((preferReg & RBM_ARG_REGS) != 0))
                 {
-                    // We are passing the ldObj in the argument registers
+                    // We are passing the 'obj' in the argument registers
                     //
                     regNumber rn = genRegNumFromMask(preferReg);
 
-                    //  Add the registers used to pass the ldObj to regMask.
+                    //  Add the registers used to pass the 'obj' to regMask.
                     for (unsigned i = 0; i < objSize/4; i++)
                     {
                         if (rn == MAX_REG_ARG)
@@ -4349,8 +4349,8 @@ HANDLE_SHIFT_COUNT:
                 }
                 else
                 {
-                    // We are passing the ldObj in the outgoing arg space
-                    // We will need one register to load into unless the ldObj size is 4 or less.
+                    // We are passing the 'obj' in the outgoing arg space
+                    // We will need one register to load into unless the 'obj' size is 4 or less.
                     //
                     if (objSize > 4)
                     {
@@ -4617,22 +4617,22 @@ HANDLE_SHIFT_COUNT:
                 GenTreePtr argx = args;
                 GenTreePtr lclVarTree = NULL;
 
-                /* The GT_LDOBJ may be be a child of a GT_COMMA */
+                /* The GT_OBJ may be be a child of a GT_COMMA */
                 while (argx->gtOper == GT_COMMA)
                 {
                     argx = argx->gtOp.gtOp2;
                 }
                 unsigned originalSize = 0;
 
-                if (argx->gtOper == GT_LDOBJ)
+                if (argx->gtOper == GT_OBJ)
                 {    
-                    originalSize = info.compCompHnd->getClassSize(argx->gtLdObj.gtClass);
+                    originalSize = info.compCompHnd->getClassSize(argx->gtObj.gtClass);
 
                     // Is it the address of a promoted struct local?
-                    if (argx->gtLdObj.gtOp1->gtOper == GT_ADDR &&
-                        argx->gtLdObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
+                    if (argx->gtObj.gtOp1->gtOper == GT_ADDR &&
+                        argx->gtObj.gtOp1->gtOp.gtOp1->gtOper == GT_LCL_VAR)
                     {
-                        lclVarTree = argx->gtLdObj.gtOp1->gtOp.gtOp1;
+                        lclVarTree = argx->gtObj.gtOp1->gtOp.gtOp1;
                         LclVarDsc* varDsc = &lvaTable[lclVarTree->gtLclVarCommon.gtLclNum];
                         if (varDsc->lvPromoted)
                             promotedStructLocal = varDsc;
@@ -4768,9 +4768,9 @@ HANDLE_SHIFT_COUNT:
                 tmpMask |= rpPredictTreeRegUse(args, argPredictReg, lockedRegs | regArgMask, RBM_LASTUSE);
             }
 
-            // We mark LDOBJ(ADDR(LOCAL)) with GTF_VAR_DEATH since the local is required to live
-            // for the duration of the LDOBJ.
-            if (args->OperGet() == GT_LDOBJ && (args->gtFlags & GTF_VAR_DEATH))
+            // We mark OBJ(ADDR(LOCAL)) with GTF_VAR_DEATH since the local is required to live
+            // for the duration of the OBJ.
+            if (args->OperGet() == GT_OBJ && (args->gtFlags & GTF_VAR_DEATH))
             {
                 GenTreePtr lclVarTree = fgIsIndirOfAddrOfLocal(args);
                 assert(lclVarTree != NULL); // Or else would not be marked with GTF_VAR_DEATH.
diff --git a/src/jit/simd.cpp b/src/jit/simd.cpp
index a3055d27d2..122972a563 100644
--- a/src/jit/simd.cpp
+++ b/src/jit/simd.cpp
@@ -656,7 +656,7 @@ GenTreePtr Compiler::impSIMDPopStack(var_types type, bool expectAddr)
     bool isParam = false;
 
     // If we have a ldobj of a SIMD local we need to transform it.
-    if (tree->OperGet() == GT_LDOBJ)
+    if (tree->OperGet() == GT_OBJ)
     {
         GenTree* addr = tree->gtOp.gtOp1;
         if ((addr->OperGet() == GT_ADDR) && isSIMDTypeLocal(addr->gtOp.gtOp1))
@@ -2240,10 +2240,6 @@ GenTreePtr Compiler::impSIMDIntrinsic(OPCODE                   opcode,
             // op2 is the second operand
             op2 = impSIMDPopStack(simdType);
             op1 = impSIMDPopStack(simdType, instMethod);
-
-            assert(op1->TypeGet() == simdType);
-            assert(op2->TypeGet() == simdType);
-
             simdTree = gtNewSIMDNode(genActualType(callType), op1, op2, SIMDIntrinsicOpInEquality, baseType, size);
             retVal = simdTree;
         }
@@ -2258,9 +2254,6 @@ GenTreePtr Compiler::impSIMDIntrinsic(OPCODE                   opcode,
             op2 = impSIMDPopStack(simdType);
             op1 = impSIMDPopStack(simdType, instMethod);
 
-            assert(op1->TypeGet() == simdType);
-            assert(op2->TypeGet() == simdType);
-
             SIMDIntrinsicID intrinsicID = impSIMDRelOp(simdIntrinsicID, clsHnd, size, &baseType, &op1, &op2);
             simdTree = gtNewSIMDNode(genActualType(callType), op1, op2, intrinsicID, baseType, size);
             retVal = simdTree;
diff --git a/src/jit/simdcodegenxarch.cpp b/src/jit/simdcodegenxarch.cpp
index f419055525..df075f5ca9 100644
--- a/src/jit/simdcodegenxarch.cpp
+++ b/src/jit/simdcodegenxarch.cpp
@@ -537,8 +537,7 @@ CodeGen::genSIMDScalarMove(var_types type, regNumber targetReg, regNumber srcReg
             }
             else
             {
-                instruction ins = getOpForSIMDIntrinsic(SIMDIntrinsicBitwiseXor, type);
-                inst_RV_RV(ins, targetReg, targetReg, targetType, emitTypeSize(targetType));
+                genSIMDZero(targetType, TYP_FLOAT, targetReg);
                 inst_RV_RV(ins_Store(type), targetReg, srcReg);
             }
             break;
@@ -556,6 +555,14 @@ CodeGen::genSIMDScalarMove(var_types type, regNumber targetReg, regNumber srcReg
     }
 }
 
+void
+CodeGen::genSIMDZero(var_types targetType, var_types baseType, regNumber targetReg)
+{
+    // pxor reg, reg
+    instruction ins = getOpForSIMDIntrinsic(SIMDIntrinsicBitwiseXor, baseType);
+    inst_RV_RV(ins, targetReg, targetReg, targetType, emitActualTypeSize(targetType));
+}
+
 //------------------------------------------------------------------------
 // genSIMDIntrinsicInit: Generate code for SIMD Intrinsic Initialize.
 //
@@ -586,9 +593,7 @@ CodeGen::genSIMDIntrinsicInit(GenTreeSIMD* simdNode)
     {
         if (op1->IsZero())
         {   
-            // pxor reg, reg
-            ins = getOpForSIMDIntrinsic(SIMDIntrinsicBitwiseXor, baseType);
-            inst_RV_RV(ins, targetReg, targetReg, targetType, emitActualTypeSize(targetType));
+            genSIMDZero(targetType, baseType, targetReg);
         }
         else if ((baseType == TYP_INT && op1->IsCnsIntOrI() && op1->AsIntConCommon()->IconValue() == 0xffffffff) ||
                  (baseType == TYP_LONG && op1->IsCnsIntOrI() && op1->AsIntConCommon()->IconValue() == 0xffffffffffffffffLL))
@@ -732,12 +737,11 @@ CodeGen::genSIMDIntrinsicInitN(GenTreeSIMD* simdNode)
     assert(genCountBits(simdNode->gtRsvdRegs) == 1);
     regNumber vectorReg = genRegNumFromMask(simdNode->gtRsvdRegs);
 
-    // Zero out vectorReg if we are constructing a vector whose size is not equal to the SIMD vector size.
+    // Zero out vectorReg if we are constructing a vector whose size is not equal to targetType vector size.
     // For example in case of Vector4f we don't need to zero when using SSE2.
     if (compiler->isSubRegisterSIMDType(simdNode))
     {
-        instruction ins = getOpForSIMDIntrinsic(SIMDIntrinsicBitwiseXor, baseType);
-        inst_RV_RV(ins, vectorReg, vectorReg, targetType, emitActualTypeSize(targetType));
+        genSIMDZero(targetType, baseType, vectorReg);
     }
 
     unsigned int baseTypeSize = genTypeSize(baseType);
diff --git a/src/jit/stackfp.cpp b/src/jit/stackfp.cpp
index 2c0150d520..eeeadbb278 100644
--- a/src/jit/stackfp.cpp
+++ b/src/jit/stackfp.cpp
@@ -4308,99 +4308,6 @@ void Compiler::raEnregisterVarsPostPassStackFP       ()
                 {
                     raSetRegLclBirthDeath(tree, lastlife, false);                   
                 }                
-                else if (tree->gtOper == GT_LDOBJ)
-                {             
-                    GenTreePtr  lclVarTree;                   
-    
-                    if (impIsAddressInLocal(tree->gtOp.gtOp1, &lclVarTree))
-                    {
-                        assert(lclVarTree->gtOper == GT_LCL_VAR);
-                        assert(lclVarTree->gtType == TYP_STRUCT);
-                        
-                        LclVarDsc   *   varDsc = lvaTable + lclVarTree->gtLclVarCommon.gtLclNum;
-
-#ifdef DEBUG
-                        if (verbose)
-                        {
-                            gtDispTree(tree);
-                        }
-#endif
-
-                        if (varDsc->lvContainsFloatingFields)
-                        {  
-                            assert(varDsc->lvPromoted);                                          
-
-                            tree->gtLdObj.gtFldTreeList = new (this, CMK_ASTNode) GenTree*[MAX_NumOfFieldsInPromotableStruct];
-#ifdef DEBUG
-                            if (verbose && 0)
-                            {
-                                printf("gtFldTreeList=");
-                                Compiler::printTreeID(*(tree->gtLdObj.gtFldTreeList));
-                                printf("\n");
-                            }
-#endif
-
-                            VARSET_TP* deadVarBits = NULL;
-                            if (lclVarTree->TypeGet() == TYP_STRUCT)
-                                GetPromotedStructDeathVars()->Lookup(lclVarTree, &deadVarBits);
-
-                            // Re-thread the floating nodes into the gtPrev/gtNext
-                            GenTreePtr prev = lclVarTree->gtPrev;
-                            for (unsigned index=0; 
-                                 index<varDsc->lvFieldCnt; 
-                                 ++index)
-                            {    
-                                LclVarDsc *  fieldVarDsc = &lvaTable[varDsc->lvFieldLclStart+index];
-
-                                if (varTypeIsFloating((var_types)fieldVarDsc->lvType))
-                                {
-                                    GenTreePtr fieldTree = gtNewLclvNode(varDsc->lvFieldLclStart+index, 
-                                                                         lvaTable[varDsc->lvFieldLclStart+index].TypeGet());
-
-                                    raSetRegLclBirthDeath(fieldTree, lastlife, true);
-                                    if ((tree->gtFlags & GTF_VAR_DEATH) != 0) 
-                                    {
-                                        if (fieldVarDsc->lvTracked && 
-                                            (deadVarBits == NULL || VarSetOps::IsMember(this, *deadVarBits, fieldVarDsc->lvVarIndex)))
-                                        {
-                                            fieldTree->gtFlags |= GTF_VAR_DEATH;
-                                        }
-                                    }
-
-                                    // Note that assignments to promoted struct fields are always "exploded", so there
-                                    // is no dual situation to the considerations above for the GTF_VAR_DEF case.
-                                    if ((lclVarTree->gtFlags & GTF_VAR_DEF) != 0) fieldTree->gtFlags |= GTF_VAR_DEF;
-
-                                    tree->gtLdObj.gtFldTreeList[index] = fieldTree;
-                                    fieldTree->gtPrev = prev;
-                                    if (prev != NULL) prev->gtNext = fieldTree;
-                                    else
-                                    {
-                                        assert (stmt->gtStmt.gtStmtList == lclVarTree);
-                                        stmt->gtStmt.gtStmtList = fieldTree;
-                                    }
-                                    prev = fieldTree;
-                                }
-                                else
-                                {
-                                    tree->gtLdObj.gtFldTreeList[index] = NULL;
-                                }
-                            }
-                            lclVarTree->gtPrev = prev;
-                            prev->gtNext = lclVarTree;
-                        }
-                        else
-                        {
-#ifdef DEBUG
-                            if (verbose)
-                            {
-                                printf("V%02u does NOT contains floating field.\n", lclVarTree->gtLclVarCommon.gtLclNum);
-                            }
-#endif                            
-                        }                        
-                    }
-                }
-                
             }
         }       
         assert(VarSetOps::Equal(this, lastlife, block->bbLiveOut));
diff --git a/src/jit/valuenum.cpp b/src/jit/valuenum.cpp
index 16183ac9c6..58c99d07bf 100644
--- a/src/jit/valuenum.cpp
+++ b/src/jit/valuenum.cpp
@@ -3567,7 +3567,7 @@ static genTreeOps genTreeOpsIllegalAsVNFunc[] = {
     GT_COPYOBJ,  // A kind of assignment.
     GT_ADDR,
     GT_ARR_BOUNDS_CHECK,
-    GT_LDOBJ,    // Heap memory.
+    GT_OBJ,      // May reference heap memory.
 
     // These control-flow operations need no values.
     GT_JTRUE,