Fix build

src/coreclr/jit/gentree.h

@@ -5588,8 +5588,9 @@ struct GenTreeCall final : public GenTree
 
     CORINFO_CLASS_HANDLE gtRetClsHnd; // The return type handle of the call if it is a struct; always available
     union {
-        void*                gtStubCallStubAddr; // GTF_CALL_VIRT_STUB - these are never inlined
-        CORINFO_CLASS_HANDLE gtInitClsHnd;       // Used by static init helpers, represents a class they init
+        void*                gtStubCallStubAddr;   // GTF_CALL_VIRT_STUB - these are never inlined
+        CORINFO_CLASS_HANDLE gtInitClsHnd;         // Used by static init helpers, represents a class they init
+        IL_OFFSET            gtCastHelperILOffset; // Used by cast helpers to save corresponding IL offset
     };
 
     union {

src/coreclr/jit/helperexpansion.cpp

@@ -1594,7 +1594,7 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
     const int               maxLikelyClasses = 8;
     LikelyClassMethodRecord likelyClasses[maxLikelyClasses];
     unsigned likelyClassCount = getLikelyClasses(likelyClasses, maxLikelyClasses, fgPgoSchema, fgPgoSchemaCount,
-                                                 fgPgoData, (int)call->gtRawILOffset);
+                                                 fgPgoData, call->gtCastHelperILOffset);
 
     if (likelyClassCount == 0)
     {
@@ -1720,7 +1720,7 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
     // typeCheckBb (BBJ_COND):                      [weight: 0.5]
     //     if (tmp->pMT == likelyClass) goto block;
     //
-    // fallbackBb (BBJ_ALWAYS):                     [weight: 0.25]
+    // fallbackBb (BBJ_ALWAYS):                     [weight: <profile>]
     //     tmp = helper_call(cls, tmp);
     //
     // block (BBJ_any):                             [weight: 1.0]
@@ -1786,12 +1786,12 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
 
     //
     // Re-distribute weights
-    // We assume obj is 50%/50% null/not-null, and if it's not null,
-    // it's 50%/50% of being of the expected type. TODO: rely on profile data
+    // We assume obj is 50%/50% null/not-null (TODO: use profile data)
+    // and rely on profile for the slow path.
     //
     nullcheckBb->inheritWeight(prevBb);
     fallbackBb->inheritWeightPercentage(nullcheckBb, 50);
-    typeCheckBb->inheritWeightPercentage(fallbackBb, 50);
+    typeCheckBb->inheritWeightPercentage(fallbackBb, 100 - likelyClass.likelihood);
     block->inheritWeight(prevBb);
 
     //

src/coreclr/jit/importer.cpp

@@ -5603,9 +5603,9 @@ GenTree* Compiler::impCastClassOrIsInstToTree(
         }
         else
         {
-            // Maybe the late-cast-expand phase can have a better luck expanding this cast.
+            // Maybe the late-cast-expand phase will have a better luck expanding this cast.
             call->gtCallMoreFlags |= GTF_CALL_M_CAST_CAN_BE_EXPANDED;
-            call->gtRawILOffset = ilOffset;
+            call->gtCastHelperILOffset = ilOffset;
         }
         return call;
     }