From b311010828ff9436beab4b6f7e3bcee3bf1fbefe Mon Sep 17 00:00:00 2001
From: Bruce Forstall <brucefo@microsoft.com>
Date: Wed, 20 Mar 2024 23:13:50 -0700
Subject: [PATCH] Remove GetFoldedArithOpResultHandleFlags

For any constant arithmetic on a handle, lose the handle type:
it's unreliable.

Eliminates problems seen in https://github.com/dotnet/runtime/issues/100059
---
 src/coreclr/jit/valuenum.cpp | 65 +++---------------------------------
 src/coreclr/jit/valuenum.h   |  2 --
 2 files changed, 5 insertions(+), 62 deletions(-)

diff --git a/src/coreclr/jit/valuenum.cpp b/src/coreclr/jit/valuenum.cpp
index 4922e1f3da0a6..fe61b1e810823 100644
--- a/src/coreclr/jit/valuenum.cpp
+++ b/src/coreclr/jit/valuenum.cpp
@@ -3593,16 +3593,12 @@ ValueNum ValueNumStore::EvalFuncForConstantArgs(var_types typ, VNFunc func, Valu
         case TYP_INT:
         {
             int resVal = EvalOp<int>(func, ConstantValue<int>(arg0VN));
-            // Unary op on a handle results in a handle.
-            return IsVNHandle(arg0VN) ? VNForHandle(ssize_t(resVal), GetFoldedArithOpResultHandleFlags(arg0VN))
-                                      : VNForIntCon(resVal);
+            return VNForIntCon(resVal);
         }
         case TYP_LONG:
         {
             INT64 resVal = EvalOp<INT64>(func, ConstantValue<INT64>(arg0VN));
-            // Unary op on a handle results in a handle.
-            return IsVNHandle(arg0VN) ? VNForHandle(ssize_t(resVal), GetFoldedArithOpResultHandleFlags(arg0VN))
-                                      : VNForLongCon(resVal);
+            return VNForLongCon(resVal);
         }
         case TYP_FLOAT:
         {
@@ -3854,16 +3850,7 @@ ValueNum ValueNumStore::EvalFuncForConstantArgs(var_types typ, VNFunc func, Valu
             {
                 assert(typ == TYP_INT);
                 int resultVal = EvalOp<int>(func, arg0Val, arg1Val);
-                // Bin op on a handle results in a handle.
-                ValueNum handleVN = IsVNHandle(arg0VN) ? arg0VN : IsVNHandle(arg1VN) ? arg1VN : NoVN;
-                if (handleVN != NoVN)
-                {
-                    result = VNForHandle(ssize_t(resultVal), GetFoldedArithOpResultHandleFlags(handleVN));
-                }
-                else
-                {
-                    result = VNForIntCon(resultVal);
-                }
+                result        = VNForIntCon(resultVal);
             }
         }
         else if (arg0VNtyp == TYP_LONG)
@@ -3879,17 +3866,8 @@ ValueNum ValueNumStore::EvalFuncForConstantArgs(var_types typ, VNFunc func, Valu
             else
             {
                 assert(typ == TYP_LONG);
-                INT64    resultVal = EvalOp<INT64>(func, arg0Val, arg1Val);
-                ValueNum handleVN  = IsVNHandle(arg0VN) ? arg0VN : IsVNHandle(arg1VN) ? arg1VN : NoVN;
-
-                if (handleVN != NoVN)
-                {
-                    result = VNForHandle(ssize_t(resultVal), GetFoldedArithOpResultHandleFlags(handleVN));
-                }
-                else
-                {
-                    result = VNForLongCon(resultVal);
-                }
+                INT64 resultVal = EvalOp<INT64>(func, arg0Val, arg1Val);
+                result          = VNForLongCon(resultVal);
             }
         }
         else // both args are TYP_REF or both args are TYP_BYREF
@@ -6191,39 +6169,6 @@ GenTreeFlags ValueNumStore::GetHandleFlags(ValueNum vn)
     return handleFlags;
 }
 
-GenTreeFlags ValueNumStore::GetFoldedArithOpResultHandleFlags(ValueNum vn)
-{
-    GenTreeFlags flags = GetHandleFlags(vn);
-    assert((flags & GTF_ICON_HDL_MASK) == flags);
-
-    switch (flags)
-    {
-        case GTF_ICON_SCOPE_HDL:
-        case GTF_ICON_CLASS_HDL:
-        case GTF_ICON_METHOD_HDL:
-        case GTF_ICON_FIELD_HDL:
-        case GTF_ICON_TOKEN_HDL:
-        case GTF_ICON_STR_HDL:
-        case GTF_ICON_OBJ_HDL:
-        case GTF_ICON_CONST_PTR:
-        case GTF_ICON_VARG_HDL:
-        case GTF_ICON_PINVKI_HDL:
-        case GTF_ICON_FTN_ADDR:
-        case GTF_ICON_CIDMID_HDL:
-        case GTF_ICON_TLS_HDL:
-        case GTF_ICON_STATIC_BOX_PTR:
-        case GTF_ICON_STATIC_ADDR_PTR:
-            return GTF_ICON_CONST_PTR;
-        case GTF_ICON_STATIC_HDL:
-        case GTF_ICON_GLOBAL_PTR:
-        case GTF_ICON_BBC_PTR:
-            return GTF_ICON_GLOBAL_PTR;
-        default:
-            assert(!"Unexpected handle type");
-            return flags;
-    }
-}
-
 bool ValueNumStore::IsVNHandle(ValueNum vn)
 {
     if (vn == NoVN)
diff --git a/src/coreclr/jit/valuenum.h b/src/coreclr/jit/valuenum.h
index ef8bd48229a15..a976893a06581 100644
--- a/src/coreclr/jit/valuenum.h
+++ b/src/coreclr/jit/valuenum.h
@@ -404,8 +404,6 @@ class ValueNumStore
     // returns true iff vn is known to be a constant int32 that is > 0
     bool IsVNPositiveInt32Constant(ValueNum vn);
 
-    GenTreeFlags GetFoldedArithOpResultHandleFlags(ValueNum vn);
-
 public:
     // Validate that the new initializer for s_vnfOpAttribs matches the old code.
     static void ValidateValueNumStoreStatics();