From 417c82b47f08907f6a991f00332ad9d68ee53dc3 Mon Sep 17 00:00:00 2001
From: Carol Eidt <carol.eidt@microsoft.com>
Date: Thu, 13 Sep 2018 16:56:01 -0700
Subject: [PATCH] Use compMatchedVM

---
 src/jit/morph.cpp | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/jit/morph.cpp b/src/jit/morph.cpp
index 47f1515..25fe1bf 100644
--- a/src/jit/morph.cpp
+++ b/src/jit/morph.cpp
@@ -8316,12 +8316,15 @@ GenTree* Compiler::fgMorphCall(GenTreeCall* call)
                                                                               : CORINFO_TAILCALL_NORMAL);
             if (pfnCopyArgs == nullptr)
             {
-#ifdef ALT_JIT
-                // If this is an altjit, we may not get a thunk from the VM, so use a fake one.
-                pfnCopyArgs = (void*)0xdddddddd;
-#else
-                szFailReason = "TailCallCopyArgsThunk not available.";
-#endif
+                if (!info.compMatchedVM)
+                {
+                    // If we don't have a matched VM, we won't get valid results when asking for a thunk.
+                    pfnCopyArgs = (void*)0xCA11CA11; // "callcall"
+                }
+                else
+                {
+                    szFailReason = "TailCallCopyArgsThunk not available.";
+                }
             }
         }
 #endif // !_TARGET_X86_
-- 
2.7.4