[RyuJit] Mark some well-known indirs with some flags (#118289)

Author: SingleAccretion

src/coreclr/jit/assertionprop.cpp

@@ -4169,7 +4169,7 @@ AssertionIndex Compiler::optGlobalAssertionIsEqualOrNotEqual(ASSERT_VALARG_TP as
 
         // Look for matching exact type assertions based on vtable accesses. E.g.:
         //
-        //   op1:       VNF_InvariantLoad(myObj) or in other words: a vtable access
+        //   op1:       VNF_InvariantNonNullLoad(myObj) or in other words: a vtable access
         //   op2:       'MyType' class handle
         //   Assertion: 'myObj's type is exactly MyType
         //
@@ -4178,7 +4178,7 @@ AssertionIndex Compiler::optGlobalAssertionIsEqualOrNotEqual(ASSERT_VALARG_TP as
         {
             VNFuncApp funcApp;
             if (vnStore->GetVNFunc(vnStore->VNConservativeNormalValue(op1->gtVNPair), &funcApp) &&
-                (funcApp.m_func == VNF_InvariantLoad) && (curAssertion->op1.vn == funcApp.m_args[0]))
+                (funcApp.m_func == VNF_InvariantNonNullLoad) && (curAssertion->op1.vn == funcApp.m_args[0]))
             {
                 return assertionIndex;
             }

src/coreclr/jit/compiler.hpp

@@ -1935,8 +1935,9 @@ inline GenTreeCast* Compiler::gtNewCastNodeL(var_types typ, GenTree* op1, bool f
 
 inline GenTreeIndir* Compiler::gtNewMethodTableLookup(GenTree* object, bool onStack)
 {
+    static_assert_no_msg(VPTR_OFFS == 0);
     assert(onStack || object->TypeIs(TYP_REF));
-    GenTreeIndir* result = gtNewIndir(TYP_I_IMPL, object, GTF_IND_INVARIANT);
+    GenTreeIndir* result = gtNewIndir(TYP_I_IMPL, object, GTF_IND_INVARIANT | GTF_IND_NONNULL);
     return result;
 }
 

src/coreclr/jit/indirectcalltransformer.cpp

@@ -415,9 +415,10 @@ class IndirectCallTransformer
         {
             elseBlock = CreateAndInsertBasicBlock(BBJ_ALWAYS, thenBlock, currBlock);
 
-            GenTree* fixedFptrAddress  = GetFixedFptrAddress();
-            GenTree* actualCallAddress = compiler->gtNewIndir(pointerType, fixedFptrAddress);
-            GenTree* hiddenArgument    = GetHiddenArgument(fixedFptrAddress);
+            GenTree* fixedFptrAddress = GetFixedFptrAddress();
+            GenTree* actualCallAddress =
+                compiler->gtNewIndir(pointerType, fixedFptrAddress, GTF_IND_NONFAULTING | GTF_IND_INVARIANT);
+            GenTree* hiddenArgument = GetHiddenArgument(fixedFptrAddress);
 
             Statement* fatStmt = CreateFatCallStmt(actualCallAddress, hiddenArgument);
             compiler->fgInsertStmtAtEnd(elseBlock, fatStmt);
@@ -448,7 +449,8 @@ class IndirectCallTransformer
             GenTree* fixedFptrAddressCopy = compiler->gtCloneExpr(fixedFptrAddress);
             GenTree* wordSize          = new (compiler, GT_CNS_INT) GenTreeIntCon(TYP_I_IMPL, genTypeSize(TYP_I_IMPL));
             GenTree* hiddenArgumentPtr = compiler->gtNewOperNode(GT_ADD, pointerType, fixedFptrAddressCopy, wordSize);
-            return compiler->gtNewIndir(fixedFptrAddressCopy->TypeGet(), hiddenArgumentPtr);
+            return compiler->gtNewIndir(fixedFptrAddressCopy->TypeGet(), hiddenArgumentPtr,
+                                        GTF_IND_NONFAULTING | GTF_IND_INVARIANT);
         }
 
         //------------------------------------------------------------------------

src/coreclr/jit/loopcloning.cpp

@@ -177,12 +177,13 @@ GenTree* LC_Ident::ToGenTree(Compiler* comp, BasicBlock* bb)
         case IndirOfLocal:
         {
             GenTree* addr = comp->gtNewLclvNode(lclNum, TYP_REF);
-            if (indirOffs != 0)
+            if (indirOffs == 0)
             {
-                addr = comp->gtNewOperNode(GT_ADD, TYP_BYREF, addr,
-                                           comp->gtNewIconNode(static_cast<ssize_t>(indirOffs), TYP_I_IMPL));
+                return comp->gtNewMethodTableLookup(addr);
             }
 
+            addr                 = comp->gtNewOperNode(GT_ADD, TYP_BYREF, addr,
+                                                       comp->gtNewIconNode(static_cast<ssize_t>(indirOffs), TYP_I_IMPL));
             GenTree* const indir = comp->gtNewIndir(TYP_I_IMPL, addr, GTF_IND_INVARIANT);
             return indir;
         }

src/coreclr/jit/morph.cpp

@@ -6608,8 +6608,7 @@ GenTree* Compiler::fgExpandVirtualVtableCallTarget(GenTreeCall* call)
                                             &isRelative);
 
     // Dereference the this pointer to obtain the method table, it is called vtab below
-    assert(VPTR_OFFS == 0); // We have to add this value to the thisPtr to get the methodTable
-    GenTree* vtab = gtNewIndir(TYP_I_IMPL, thisPtr, GTF_IND_INVARIANT);
+    GenTree* vtab = gtNewMethodTableLookup(thisPtr);
 
     if (fgGlobalMorph)
     {