title: Apply LLVM pass to a specific basic block
body: <p>Is it possible to apply LLVM transformation pass to a specific basic block, instead of the whole IR?</p>
  
  <p>I know how to apply a pass to the whole IR:
  $ opt –S –instcombine test.ll –o out.ll</p>
  
  <p>But there might be several basic blocks inside test.ll and I want to apply –instcombine  to just one of them.</p>