Verify that MachineMemOperand alignment is a non-zero power of 2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53262 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineInstr.cpp

@@ -246,6 +246,7 @@ MachineMemOperand::MachineMemOperand(const Value *v, unsigned int f,
                                      int64_t o, uint64_t s, unsigned int a)
   : Offset(o), Size(s), V(v),
     Flags((f & 7) | ((Log2_32(a) + 1) << 3)) {
+  assert(isPowerOf2_32(a) && "Alignment is not a power of 2!");
 }
 
 //===----------------------------------------------------------------------===//