1 files changed, 11 insertions, 29 deletions

diff --git a/src/jit/rationalize.cpp b/src/jit/rationalize.cpp
index 1cdb54f214..d51634b6db 100644
--- a/src/jit/rationalize.cpp
+++ b/src/jit/rationalize.cpp
@@ -552,7 +552,7 @@ void Rationalizer::RewriteAddress(LIR::Use& use)
     JITDUMP("\n");
 }
 
-Compiler::fgWalkResult Rationalizer::RewriteNode(GenTree** useEdge, ArrayStack<GenTree*>& parentStack)
+Compiler::fgWalkResult Rationalizer::RewriteNode(GenTree** useEdge, Compiler::GenTreeStack& parentStack)
 {
     assert(useEdge != nullptr);
 
@@ -755,39 +755,21 @@ Compiler::fgWalkResult Rationalizer::RewriteNode(GenTree** useEdge, ArrayStack<G
             assert(comp->IsTargetIntrinsic(node->gtIntrinsic.gtIntrinsicId));
             break;
 
-#ifdef FEATURE_SIMD
         case GT_BLK:
+            // We should only see GT_BLK for TYP_STRUCT.
+            assert(node->TypeGet() == TYP_STRUCT);
+            break;
+
         case GT_OBJ:
-        {
-            // TODO-1stClassStructs: These should have been transformed to GT_INDs, but in order
-            // to preserve existing behavior, we will keep this as a block node if this is the
-            // lhs of a block assignment, and either:
-            // - It is a "generic" TYP_STRUCT assignment, OR
-            // - It is an initblk, OR
-            // - Neither the lhs or rhs are known to be of SIMD type.
-
-            GenTree* parent  = use.User();
-            bool     keepBlk = false;
-            if ((parent->OperGet() == GT_ASG) && (node == parent->gtGetOp1()))
+            assert(node->TypeGet() == TYP_STRUCT || !use.User()->OperIsInitBlkOp());
+            if (varTypeIsSIMD(node))
             {
-                if ((node->TypeGet() == TYP_STRUCT) || parent->OperIsInitBlkOp())
-                {
-                    keepBlk = true;
-                }
-                else if (!comp->isAddrOfSIMDType(node->AsBlk()->Addr()))
-                {
-                    GenTree* dataSrc = parent->gtGetOp2();
-                    if (!dataSrc->IsLocal() && (dataSrc->OperGet() != GT_SIMD) && (!dataSrc->OperIsHWIntrinsic()))
-                    {
-                        noway_assert(dataSrc->OperIsIndir());
-                        keepBlk = !comp->isAddrOfSIMDType(dataSrc->AsIndir()->Addr());
-                    }
-                }
+                // Rewrite these as GT_IND.
+                RewriteSIMDOperand(use, false);
             }
-            RewriteSIMDOperand(use, keepBlk);
-        }
-        break;
+            break;
 
+#ifdef FEATURE_SIMD
         case GT_SIMD:
         {
             noway_assert(comp->featureSIMD);