1 files changed, 9 insertions, 1 deletions
diff --git a/llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp
index 88d353e..e0e3173 100644
--- a/llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp
@@ -3616,7 +3616,15 @@ public:
       hasChain = true;
 
     if (const CodeGenIntrinsic *IntInfo = N.getIntrinsicInfo(CDP)) {
-      ModRefInfo MR = IntInfo->ME.getModRef();
+      // Ignore reads/writes to inaccessible memory. These should not imply
+      // mayLoad/mayStore on the instruction because they are often used to
+      // model dependencies that Machine IR expresses as uses/defs of a
+      // special physical register.
+      ModRefInfo MR = ModRefInfo::NoModRef;
+      for (MemoryEffects::Location Loc : MemoryEffects::locations()) {
+        if (Loc != MemoryEffects::Location::InaccessibleMem)
+          MR |= IntInfo->ME.getModRef();
+      }
       // If this is an intrinsic, analyze it.
       if (isRefSet(MR))
         mayLoad = true; // These may load memory.