Fix an issue where the two-address conversion pass incorrectly rewrites untied

[oota-llvm.git] / lib / CodeGen / MachineRegisterInfo.cpp

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 7244d5f03a90a8fd7e6de3d97e53a8ed4a9f3d4f..08ff5bb715212a58ef92f771b41e78746c6a6bbd 100644 (file)
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -79,6 +79,8 @@ MachineRegisterInfo::constrainRegClass(unsigned Reg,
 unsigned
 MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass){
   assert(RegClass && "Cannot create register without RegClass!");
+  assert(RegClass->isAllocatable() &&
+         "Virtual register RegClass must be allocatable.");
 
   // New virtual register number.
   unsigned Reg = TargetRegisterInfo::index2VirtReg(getNumVirtRegs());