Summary:
Even though there is no 2nd register operand in the "lw/sw $8, symbol" case, we still try to find one,
and we end up with $0, which makes us generate an unnecessary "addu $8, $8, $0" (a.k.a. "move $8, $8").
We can avoid this by checking if the 2nd register operand is different from $0, before generating the addu.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8055
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234406 91177308-0d34-0410-b5e6-96231b3b80d8
