1549a2f46a
Restrict the creation of compact branches so that they meet the ISA encoding requirements. Notably do not permit $zero to be used as a operand for compact branches and ensure that some other branches fulfil the requirement that rs != rt. Fixup cases where $rs > $rt for bnec and beqc. Reviewers: dsanders, vkalintiris Differential Review: http://reviews.llvm.org/D20284 llvm-svn: 269893