diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -4447,6 +4447,10 @@
   if (TypeIdx != 0)
     return UnableToLegalize;
 
+  // FIXME: add support for vector types
+  if (MRI.getType(MI.getOperand(0).getReg()).isVector())
+    return UnableToLegalize;
+
   uint64_t SizeOp0 = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
   uint64_t NarrowSize = NarrowTy.getSizeInBits();
 
@@ -4493,10 +4497,7 @@
     CarryIn = CarryOut;
   }
   Register DstReg = MI.getOperand(0).getReg();
-  if (MRI.getType(DstReg).isVector())
-    MIRBuilder.buildBuildVector(DstReg, DstRegs);
-  else
-    MIRBuilder.buildMerge(DstReg, DstRegs);
+  MIRBuilder.buildMerge(DstReg, DstRegs);
   MI.eraseFromParent();
   return Legalized;
 }