Pass Vector<T> by reference when InstructionSet_VectorT is available

src/coreclr/inc/cor.h

@@ -1665,6 +1665,14 @@ FORCEINLINE int CorIsPrimitiveType(CorElementType elementtype)
     return (elementtype < ELEMENT_TYPE_PTR || elementtype == ELEMENT_TYPE_I || elementtype == ELEMENT_TYPE_U);
 }
 
+// Returns true if the element type is a real or integer type.
+FORCEINLINE bool CorIsNumericalType(CorElementType elementType)
+{
+    return ((elementType >= ELEMENT_TYPE_I1) && (elementType <= ELEMENT_TYPE_R8))
+        || (elementType == ELEMENT_TYPE_I)
+        || (elementType == ELEMENT_TYPE_U);
+}
+
 
 // Return true if element type is a modifier, i.e. ELEMENT_TYPE_MODIFIER bits are
 // turned on. For now, it is checking for ELEMENT_TYPE_PTR and ELEMENT_TYPE_BYREF

src/coreclr/vm/class.cpp

@@ -1685,45 +1685,64 @@ bool MethodTable::IsHFA()
 #endif // !FEATURE_HFA
 
 //*******************************************************************************
-int MethodTable::GetVectorSize()
+CorInfoHFAElemType MethodTable::GetVectorHFA()
 {
     // This is supported for finding HVA types for Arm64. In order to support the altjit,
     // we support this on 64-bit platforms (i.e. Arm64 and X64).
+    CorInfoHFAElemType hfaType = CORINFO_HFA_ELEM_NONE;
 #ifdef TARGET_64BIT
     if (IsIntrinsicType())
     {
         LPCUTF8 namespaceName;
         LPCUTF8 className = GetFullyQualifiedNameInfo(&namespaceName);
-        int vectorSize = 0;
 
         if (strcmp(className, "Vector`1") == 0)
         {
             _ASSERTE(strcmp(namespaceName, "System.Numerics") == 0);
-            vectorSize = GetNumInstanceFieldBytes();
+#ifdef TARGET_ARM64
+            if (ExecutionManager::GetEEJitManager()->UseScalableVectorT())
+            {
+                // TODO-SVE: This forces Vector<T> to be passed by reference. Implement
+                // CORINFO_HFA_ELEM_VECTORT so we can pass Vector<T> in SVE registers.
+                return CORINFO_HFA_ELEM_NONE;
+            }
+#endif
+            switch (GetNumInstanceFieldBytes())
+            {
+                case 8:
+                    hfaType = CORINFO_HFA_ELEM_VECTOR64;
+                    break;
+                case 16:
+                    hfaType = CORINFO_HFA_ELEM_VECTOR128;
+                    break;
+                default:
+                    _ASSERTE(!"Invalid Vector<T> size");
+                    break;
+            }
         }
         else if (strcmp(className, "Vector128`1") == 0)
         {
             _ASSERTE(strcmp(namespaceName, "System.Runtime.Intrinsics") == 0);
-            vectorSize = 16;
+            hfaType = CORINFO_HFA_ELEM_VECTOR128;
         }
         else if (strcmp(className, "Vector64`1") == 0)
         {
             _ASSERTE(strcmp(namespaceName, "System.Runtime.Intrinsics") == 0);
-            vectorSize = 8;
+            hfaType = CORINFO_HFA_ELEM_VECTOR64;
         }
-        if (vectorSize != 0)
+
+        if (hfaType != CORINFO_HFA_ELEM_NONE)
         {
-            // We need to verify that T (the element or "base" type) is a primitive type.
+            // We need to verify that T (the element or "base" type) is a numerical type.
             TypeHandle typeArg = GetInstantiation()[0];
-            CorElementType corType = typeArg.GetSignatureCorElementType();
-            if (((corType >= ELEMENT_TYPE_I1) && (corType <= ELEMENT_TYPE_R8)) || (corType == ELEMENT_TYPE_I) || (corType == ELEMENT_TYPE_U))
+            if (!CorIsNumericalType(typeArg.GetSignatureCorElementType()))
             {
-                return vectorSize;
+                return CORINFO_HFA_ELEM_NONE;
             }
         }
     }
 #endif // TARGET_64BIT
-    return 0;
+    return hfaType;
 }
 
 //*******************************************************************************
@@ -1745,10 +1764,11 @@ CorInfoHFAElemType MethodTable::GetHFAType()
         _ASSERTE(pMT->IsValueType());
         _ASSERTE(pMT->GetNumInstanceFields() > 0);
 
-        int vectorSize = pMT->GetVectorSize();
-        if (vectorSize != 0)
+        CorInfoHFAElemType hfaType = pMT->GetVectorHFA();
+
+        if (hfaType != CORINFO_HFA_ELEM_NONE)
         {
-            return (vectorSize == 8) ? CORINFO_HFA_ELEM_VECTOR64 : CORINFO_HFA_ELEM_VECTOR128;
+            return hfaType;
         }
 
         PTR_FieldDesc pFirstField = pMT->GetApproxFieldDescListRaw();
@@ -1817,7 +1837,7 @@ EEClass::CheckForHFA()
 
     // The opaque Vector types appear to have multiple fields, but need to be treated
     // as an opaque type of a single vector.
-    if (GetMethodTable()->GetVectorSize() != 0)
+    if (GetMethodTable()->GetVectorHFA() != CORINFO_HFA_ELEM_NONE)
     {
 #if defined(FEATURE_HFA)
         GetMethodTable()->SetIsHFA();
@@ -1843,27 +1863,13 @@ EEClass::CheckForHFA()
         {
         case ELEMENT_TYPE_VALUETYPE:
             {
-#ifdef TARGET_ARM64
                 MethodTable* pMT;
 #if defined(FEATURE_HFA)
                 pMT = pByValueClassCache[i];
 #else
                 pMT = pFD->LookupApproxFieldTypeHandle().AsMethodTable();
 #endif
-                int thisElemSize = pMT->GetVectorSize();
-                if (thisElemSize != 0)
-                {
-                    fieldHFAType = (thisElemSize == 8) ? CORINFO_HFA_ELEM_VECTOR64 : CORINFO_HFA_ELEM_VECTOR128;
-                }
-                else
-#endif // TARGET_ARM64
-                {
-#if defined(FEATURE_HFA)
-                    fieldHFAType = pByValueClassCache[i]->GetHFAType();
-#else
-                    fieldHFAType = pFD->LookupApproxFieldTypeHandle().AsMethodTable()->GetHFAType();
-#endif
-                }
+                fieldHFAType = pMT->GetHFAType();
 
                 int requiredAlignment;
                 switch (fieldHFAType)

src/coreclr/vm/codeman.h

@@ -2221,6 +2221,14 @@ class EEJitManager final : public EECodeGenManager
         return m_CPUCompileFlags;
     }
 
+#if defined(TARGET_ARM64)
+    inline bool UseScalableVectorT()
+    {
+        LIMITED_METHOD_CONTRACT;
+        return m_CPUCompileFlags.GetInstructionSetFlags().HasInstructionSet(InstructionSet_VectorT);
+    }
+#endif
+
 private :
     Crst                m_JitLoadLock;
 

src/coreclr/vm/methodtable.h

@@ -2045,8 +2045,10 @@ class MethodTable
     bool IsHFA();
 #endif // FEATURE_HFA
 
-    // Returns the size in bytes of this type if it is a HW vector type; 0 otherwise.
-    int GetVectorSize();
+    // Returns the HFA type for this type, if it is a valid HW vector type.
+    // Floating point HFA types will return CORINFO_HFA_ELEM_NONE.
+    // Vector classes with invalid generic parameters return CORINFO_HFA_ELEM_NONE.
+    CorInfoHFAElemType GetVectorHFA();
 
     // Get the HFA type. This is supported both with FEATURE_HFA, in which case it
     // depends on the cached bit on the class, or without, in which case it is recomputed