The expensive buildbots highlighted the mir tests were broken, which
I've now updated and added --verify-machineinstrs to them. This also
uncovered a couple of bugs in the backend pass, so these have also
been fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364323 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce three pseudo instructions to be used during DAG ISel to
represent v8.1-m low-overhead loops. One maps to set_loop_iterations
while loop_decrement_reg is lowered to two, so that we can separate
the decrement and branching operations. The pseudo instructions are
expanded pre-emission, where we can still decide whether we actually
want to generate a low-overhead loop, in a new pass:
ARMLowOverheadLoops. The pass currently bails, reverting to an sub,
icmp and br, in the cases where a call or stack spill/restore happens
between the decrement and branching instructions, or if the loop is
too large.
Differential Revision: https://reviews.llvm.org/D63476
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364288 91177308-0d34-0410-b5e6-96231b3b80d8
