If an instruction has a true dependency, it makes sense for to use that
register for any undef read operands in the same instruction (we'll have
to wait for that register to become available anyway). This logic
was already implemented. However, the code would then still try to
revisit that instruction and break the dependency (and always fail,
since by definition a true dependency has to be live before the
instruction). Avoid revisiting such instructions as a performance
optimization. No functional change.
Differential Revision: https://reviews.llvm.org/D30173
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299467 91177308-0d34-0410-b5e6-96231b3b80d8
Let targets specialize the pass with the register class so we can get a
parameterless default constructor and can put the pass into the pass
registry to enable testing with -run-pass=.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298184 91177308-0d34-0410-b5e6-96231b3b80d8
