[X86][AMX] Add check for potentially dereferencing null return value

Reviewed By: xiangzhangllvm

Differential Revision: https://reviews.llvm.org/D147921

diff --git a/llvm/lib/Target/X86/X86LowerAMXType.cpp b/llvm/lib/Target/X86/X86LowerAMXType.cpp
index 547f897..6966ee4 100644 (file)
--- a/llvm/lib/Target/X86/X86LowerAMXType.cpp
+++ b/llvm/lib/Target/X86/X86LowerAMXType.cpp
@@ -488,7 +488,7 @@ static void replaceWithTileLoad(Use &U, Value *Ptr, bool IsPHI = false) {
   // Get tile shape.
   IntrinsicInst *II = nullptr;
   if (IsPHI) {
-    Value *PhiOp = dyn_cast<PHINode>(V)->getIncomingValue(0);
+    Value *PhiOp = cast<PHINode>(V)->getIncomingValue(0);
     II = cast<IntrinsicInst>(PhiOp);
   } else {
     II = cast<IntrinsicInst>(V);