Struct & SIMD improvements (#22255)

* [WIP] Struct & SIMD improvements

- Enable CSE of struct values when handle is available (and add code to get the handle of HW SIMD types)
- Don't require block nodes for SIMD assignments
- Don't set `GTF_GLOB_REF` on `GT_OBJ` if it is local
- Set `lvRegStruct` on promoted SIMD fields
- Add tests for #19910 (fixed with this PR) and #3539 & #19438 (fixed with #21314)
- Additional cleanup

Fix #19910

1 files changed, 30 insertions, 0 deletions

diff --git a/src/jit/gentree.cpp b/src/jit/gentree.cpp
index 2b6520682c..93de32a480 100644
--- a/src/jit/gentree.cpp
+++ b/src/jit/gentree.cpp
@@ -16529,15 +16529,45 @@ CORINFO_CLASS_HANDLE Compiler::gtGetStructHandleIfPresent(GenTree* tree)
                 if (varTypeIsSIMD(tree))
                 {
                     structHnd = gtGetStructHandleForSIMD(tree->gtType, TYP_FLOAT);
+#ifdef FEATURE_HW_INTRINSICS
+                    if (structHnd == NO_CLASS_HANDLE)
+                    {
+                        structHnd = gtGetStructHandleForHWSIMD(tree->gtType, TYP_FLOAT);
+                    }
+#endif
                 }
                 else
 #endif
                 {
+                    // Attempt to find a handle for this expression.
+                    // We can do this for an array element indirection, or for a field indirection.
                     ArrayInfo arrInfo;
                     if (TryGetArrayInfo(tree->AsIndir(), &arrInfo))
                     {
                         structHnd = EncodeElemType(arrInfo.m_elemType, arrInfo.m_elemStructType);
                     }
+                    else
+                    {
+                        GenTree* addr = tree->AsIndir()->Addr();
+                        if ((addr->OperGet() == GT_ADD) && addr->gtGetOp2()->OperIs(GT_CNS_INT))
+                        {
+                            FieldSeqNode* fieldSeq = addr->gtGetOp2()->AsIntCon()->gtFieldSeq;
+
+                            if (fieldSeq != nullptr)
+                            {
+                                while (fieldSeq->m_next != nullptr)
+                                {
+                                    fieldSeq = fieldSeq->m_next;
+                                }
+                                if (fieldSeq != FieldSeqStore::NotAField() && !fieldSeq->IsPseudoField())
+                                {
+                                    CORINFO_FIELD_HANDLE fieldHnd = fieldSeq->m_fieldHnd;
+                                    CorInfoType fieldCorType = info.compCompHnd->getFieldType(fieldHnd, &structHnd);
+                                    assert(fieldCorType == CORINFO_TYPE_VALUECLASS);
+                                }
+                            }
+                        }
+                    }
                 }
                 break;
 #ifdef FEATURE_SIMD