Index: include/llvm/CodeGen/GlobalISel/CallLowering.h
===================================================================
--- include/llvm/CodeGen/GlobalISel/CallLowering.h
+++ include/llvm/CodeGen/GlobalISel/CallLowering.h
@@ -49,7 +49,10 @@
 
     ArgInfo(unsigned Reg, Type *Ty, ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy{},
             bool IsFixed = true)
-        : Reg(Reg), Ty(Ty), Flags(Flags), IsFixed(IsFixed) {}
+      : Reg(Reg), Ty(Ty), Flags(Flags), IsFixed(IsFixed) {
+      assert((Ty->isVoidTy() == (Reg == 0)) &&
+             "only void types should have no register");
+    }
   };
 
   /// Argument handling is mostly uniform between the four places that
Index: lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1222,8 +1222,9 @@
   MCSymbol *BeginSymbol = Context.createTempSymbol();
   MIRBuilder.buildInstr(TargetOpcode::EH_LABEL).addSym(BeginSymbol);
 
-  unsigned Res =
-        MRI->createGenericVirtualRegister(getLLTForType(*I.getType(), *DL));
+  unsigned Res = 0;
+  if (!I.getType()->isVoidTy())
+    Res = MRI->createGenericVirtualRegister(getLLTForType(*I.getType(), *DL));
   SmallVector<unsigned, 8> Args;
   for (auto &Arg: I.arg_operands())
     Args.push_back(packRegs(*Arg, MIRBuilder));