unsigned createVirtualRegister(const TargetRegisterClass *RegClass) {
assert(RegClass && "Cannot create register without RegClass!");
// Add a reg, but keep track of whether the vector reallocated or not.
- void *ArrayBase = &VRegInfo[0];
+ void *ArrayBase = VRegInfo.empty() ? 0 : &VRegInfo[0];
VRegInfo.push_back(std::make_pair(RegClass, (MachineOperand*)0));
- if (&VRegInfo[0] == ArrayBase)
+ if (&VRegInfo[0] == ArrayBase || VRegInfo.size() == 1)
return getLastVirtReg();
// Otherwise, the vector reallocated, handle this now.