Extract LowerStoreIndirCommon, LowerIndir.

Extract without changes, I will need to add additional calls to them later.

src/coreclr/src/jit/lower.cpp

@@ -113,64 +113,11 @@ GenTree* Lowering::LowerNode(GenTree* node)
     {
         case GT_NULLCHECK:
         case GT_IND:
-            // Process struct typed indirs separately unless they are unused;
-            // they only appear as the source of a block copy operation or a return node.
-            if (!node->TypeIs(TYP_STRUCT) || node->IsUnusedValue())
-            {
-                // TODO-Cleanup: We're passing isContainable = true but ContainCheckIndir rejects
-                // address containment in some cases so we end up creating trivial (reg + offfset)
-                // or (reg + reg) LEAs that are not necessary.
-                TryCreateAddrMode(node->AsIndir()->Addr(), true);
-                ContainCheckIndir(node->AsIndir());
-
-                if (node->OperIs(GT_NULLCHECK) || node->IsUnusedValue())
-                {
-                    // A nullcheck is essentially the same as an indirection with no use.
-                    // The difference lies in whether a target register must be allocated.
-                    // On XARCH we can generate a compare with no target register as long as the addresss
-                    // is not contained.
-                    // On ARM64 we can generate a load to REG_ZR in all cases.
-                    // However, on ARM we must always generate a load to a register.
-                    // In the case where we require a target register, it is better to use GT_IND, since
-                    // GT_NULLCHECK is a non-value node and would therefore require an internal register
-                    // to use as the target. That is non-optimal because it will be modeled as conflicting
-                    // with the source register(s).
-                    // So, to summarize:
-                    // - On ARM64, always use GT_NULLCHECK for a dead indirection.
-                    // - On ARM, always use GT_IND.
-                    // - On XARCH, use GT_IND if we have a contained address, and GT_NULLCHECK otherwise.
-                    // In all cases, change the type to TYP_INT.
-                    //
-                    node->gtType = TYP_INT;
-#ifdef TARGET_ARM64
-                    bool useNullCheck = true;
-#elif TARGET_ARM
-                    bool useNullCheck = false;
-#else  // TARGET_XARCH
-                    bool useNullCheck = !node->AsIndir()->Addr()->isContained();
-#endif // !TARGET_XARCH
-
-                    if (useNullCheck && node->OperIs(GT_IND))
-                    {
-                        node->ChangeOper(GT_NULLCHECK);
-                        node->ClearUnusedValue();
-                    }
-                    else if (!useNullCheck && node->OperIs(GT_NULLCHECK))
-                    {
-                        node->ChangeOper(GT_IND);
-                        node->SetUnusedValue();
-                    }
-                }
-            }
+            LowerIndir(node->AsIndir());
             break;
 
         case GT_STOREIND:
-            assert(node->TypeGet() != TYP_STRUCT);
-            TryCreateAddrMode(node->AsIndir()->Addr(), true);
-            if (!comp->codeGen->gcInfo.gcIsWriteBarrierStoreIndNode(node))
-            {
-                LowerStoreIndir(node->AsIndir());
-            }
+            LowerStoreIndirCommon(node->AsIndir());
             break;
 
         case GT_ADD:
@@ -6365,3 +6312,80 @@ void Lowering::ContainCheckBitCast(GenTree* node)
         op1->SetContained();
     }
 }
+
+//------------------------------------------------------------------------
+// LowerStoreIndirCommon: a common logic to lower StoreIndir.
+//
+// Arguments:
+//    ind - the store indirection node we are lowering.
+//
+void Lowering::LowerStoreIndirCommon(GenTreeIndir* ind)
+{
+    assert(ind->OperIs(GT_STOREIND));
+    assert(ind->TypeGet() != TYP_STRUCT);
+    TryCreateAddrMode(ind->Addr(), true);
+    if (!comp->codeGen->gcInfo.gcIsWriteBarrierStoreIndNode(ind))
+    {
+        LowerStoreIndir(ind);
+    }
+}
+
+//------------------------------------------------------------------------
+// LowerIndir: a common logic to lower IND load or NullCheck.
+//
+// Arguments:
+//    node - the ind node we are lowering.
+//
+void Lowering::LowerIndir(GenTreeIndir* ind)
+{
+    assert(ind->OperIs(GT_IND, GT_NULLCHECK));
+    // Process struct typed indirs separately unless they are unused;
+    // they only appear as the source of a block copy operation or a return node.
+    if (!ind->TypeIs(TYP_STRUCT) || ind->IsUnusedValue())
+    {
+        // TODO-Cleanup: We're passing isContainable = true but ContainCheckIndir rejects
+        // address containment in some cases so we end up creating trivial (reg + offfset)
+        // or (reg + reg) LEAs that are not necessary.
+        TryCreateAddrMode(ind->Addr(), true);
+        ContainCheckIndir(ind);
+
+        if (ind->OperIs(GT_NULLCHECK) || ind->IsUnusedValue())
+        {
+            // A nullcheck is essentially the same as an indirection with no use.
+            // The difference lies in whether a target register must be allocated.
+            // On XARCH we can generate a compare with no target register as long as the addresss
+            // is not contained.
+            // On ARM64 we can generate a load to REG_ZR in all cases.
+            // However, on ARM we must always generate a load to a register.
+            // In the case where we require a target register, it is better to use GT_IND, since
+            // GT_NULLCHECK is a non-value node and would therefore require an internal register
+            // to use as the target. That is non-optimal because it will be modeled as conflicting
+            // with the source register(s).
+            // So, to summarize:
+            // - On ARM64, always use GT_NULLCHECK for a dead indirection.
+            // - On ARM, always use GT_IND.
+            // - On XARCH, use GT_IND if we have a contained address, and GT_NULLCHECK otherwise.
+            // In all cases, change the type to TYP_INT.
+            //
+            ind->gtType = TYP_INT;
+#ifdef TARGET_ARM64
+            bool useNullCheck = true;
+#elif TARGET_ARM
+            bool useNullCheck = false;
+#else  // TARGET_XARCH
+            bool useNullCheck = !ind->Addr()->isContained();
+#endif // !TARGET_XARCH
+
+            if (useNullCheck && ind->OperIs(GT_IND))
+            {
+                ind->ChangeOper(GT_NULLCHECK);
+                ind->ClearUnusedValue();
+            }
+            else if (!useNullCheck && ind->OperIs(GT_NULLCHECK))
+            {
+                ind->ChangeOper(GT_IND);
+                ind->SetUnusedValue();
+            }
+        }
+    }
+}

src/coreclr/src/jit/lower.h

@@ -283,6 +283,8 @@ class Lowering final : public Phase
 #endif // defined(TARGET_XARCH)
 
     // Per tree node member functions
+    void LowerStoreIndirCommon(GenTreeIndir* ind);
+    void LowerIndir(GenTreeIndir* ind);
     void LowerStoreIndir(GenTreeIndir* node);
     GenTree* LowerAdd(GenTreeOp* node);
     bool LowerUnsignedDivOrMod(GenTreeOp* divMod);