3 files changed, 11 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 158502ce353..405e508b51e 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -970,10 +970,7 @@ bool MIParser::parseRegisterOperand(MachineOperand &Dest,
       TiedDefIdx = Idx;
     }
   } else if (consumeIfPresent(MIToken::lparen)) {
-    // Generic virtual registers must have a size.
-    // The "must" part will be verify by the machine verifier,
-    // because at this point we actually do not know if Reg is
-    // a generic virtual register.
+    // Virtual registers may have a size with GlobalISel.
     if (!TargetRegisterInfo::isVirtualRegister(Reg))
       return error("unexpected size on physical register");
     unsigned Size;
@@ -982,6 +979,11 @@ bool MIParser::parseRegisterOperand(MachineOperand &Dest,
 
     MachineRegisterInfo &MRI = MF.getRegInfo();
     MRI.setSize(Reg, Size);
+  } else if (PFS.GenericVRegs.count(Reg)) {
+    // Generic virtual registers must have a size.
+    // If we end up here this means the size hasn't been specified and
+    // this is bad!
+    return error("generic virtual registers must have a size");
   }
   Dest = MachineOperand::CreateReg(
       Reg, Flags & RegState::Define, Flags & RegState::Implicit,
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.h b/llvm/lib/CodeGen/MIRParser/MIParser.h
index ce39805e0c5..3557b9a6d5d 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.h
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.h
@@ -15,6 +15,7 @@
 #define LLVM_LIB_CODEGEN_MIRPARSER_MIPARSER_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
 
 namespace llvm {
 
@@ -35,6 +36,8 @@ struct PerFunctionMIParsingState {
   DenseMap<unsigned, int> StackObjectSlots;
   DenseMap<unsigned, unsigned> ConstantPoolSlots;
   DenseMap<unsigned, unsigned> JumpTableSlots;
+  /// Hold the generic virtual registers.
+  SmallSet<unsigned, 8> GenericVRegs;
 };
 
 /// Parse the machine basic block definitions, and skip the machine
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 69aae373f2e..e977973b1a5 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -365,6 +365,7 @@ bool MIRParserImpl::initializeRegisterInfo(MachineFunction &MF,
       // This is a generic virtual register.
       // The size will be set appropriately when we reach the definition.
       Reg = RegInfo.createGenericVirtualRegister(/*Size*/ 1);
+      PFS.GenericVRegs.insert(Reg);
     } else {
       const auto *RC = getRegClass(MF, VReg.Class.Value);
       if (RC) {
@@ -378,6 +379,7 @@ bool MIRParserImpl::initializeRegisterInfo(MachineFunction &MF,
                   VReg.Class.Value + "'");
         Reg = RegInfo.createGenericVirtualRegister(/*Size*/ 1);
         RegInfo.setRegBank(Reg, *RegBank);
+        PFS.GenericVRegs.insert(Reg);
       }
     }
     if (!PFS.VirtualRegisterSlots.insert(std::make_pair(VReg.ID.Value, Reg))