[llvm-commits] [llvm] r45526 - /llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h

[Chris Lattner]

Author: lattner
Date: Wed Jan  2 19:25:31 2008
New Revision: 45526

URL: http://llvm.org/viewvc/llvm-project?rev=45526&view=rev
Log:
don't access element zero of an array of size zero.

Modified:
    llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h

Modified: llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h?rev=45526&r1=45525&r2=45526&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h Wed Jan  2 19:25:31 2008
@@ -108,10 +108,10 @@
   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.