Fix exception sets for indirections in value numbering. (#22542)

fgValueNumberAddExceptionSetForIndirection had a bug
where INDIR(ADD(x, <big_offset>)) had NullReferenceException(x)
added instead of NullReferenceException(ADD(x, <big_offset>)).

Fixes #20358.

1 files changed, 16 insertions, 16 deletions

diff --git a/src/jit/valuenum.cpp b/src/jit/valuenum.cpp
index adb7b7b8f3..dd4ce0524c 100644
--- a/src/jit/valuenum.cpp
+++ b/src/jit/valuenum.cpp
@@ -9239,15 +9239,6 @@ void Compiler::fgValueNumberAddExceptionSetForIndirection(GenTree* tree, GenTree
     while (vnStore->GetVNFunc(baseLVN, &funcAttr) && (funcAttr.m_func == (VNFunc)GT_ADD) &&
            (vnStore->TypeOfVN(baseLVN) == TYP_BYREF))
     {
-        if (fgIsBigOffset(offsetL))
-        {
-            // Failure: Exit this loop if we have a "big" offset
-
-            // reset baseLVN back to the full address expression
-            baseLVN = baseVNP.GetLiberal();
-            break;
-        }
-
         // The arguments in value numbering functions are sorted in increasing order
         // Thus either arg could be the constant.
         if (vnStore->IsVNConstant(funcAttr.m_args[0]) && varTypeIsIntegral(vnStore->TypeOfVN(funcAttr.m_args[0])))
@@ -9264,20 +9255,20 @@ void Compiler::fgValueNumberAddExceptionSetForIndirection(GenTree* tree, GenTree
         {
             break;
         }
-    }
 
-    while (vnStore->GetVNFunc(baseCVN, &funcAttr) && (funcAttr.m_func == (VNFunc)GT_ADD) &&
-           (vnStore->TypeOfVN(baseCVN) == TYP_BYREF))
-    {
-        if (fgIsBigOffset(offsetC))
+        if (fgIsBigOffset(offsetL))
         {
             // Failure: Exit this loop if we have a "big" offset
 
-            // reset baseCVN back to the full address expression
-            baseCVN = baseVNP.GetConservative();
+            // reset baseLVN back to the full address expression
+            baseLVN = baseVNP.GetLiberal();
             break;
         }
+    }
 
+    while (vnStore->GetVNFunc(baseCVN, &funcAttr) && (funcAttr.m_func == (VNFunc)GT_ADD) &&
+           (vnStore->TypeOfVN(baseCVN) == TYP_BYREF))
+    {
         // The arguments in value numbering functions are sorted in increasing order
         // Thus either arg could be the constant.
         if (vnStore->IsVNConstant(funcAttr.m_args[0]) && varTypeIsIntegral(vnStore->TypeOfVN(funcAttr.m_args[0])))
@@ -9294,6 +9285,15 @@ void Compiler::fgValueNumberAddExceptionSetForIndirection(GenTree* tree, GenTree
         {
             break;
         }
+
+        if (fgIsBigOffset(offsetC))
+        {
+            // Failure: Exit this loop if we have a "big" offset
+
+            // reset baseCVN back to the full address expression
+            baseCVN = baseVNP.GetConservative();
+            break;
+        }
     }
 
     // Create baseVNP, from the values we just computed,