Avoid iterating every operand of an instruction in StrongPHIElimination, since
we are only interested in the defs when discovering interferences.

This is a 28% speedup running StrongPHIElimination on 403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122596 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed