diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp index e0344ef7902..13e84fa6785 100644 --- a/lib/CodeGen/TailDuplication.cpp +++ b/lib/CodeGen/TailDuplication.cpp @@ -691,13 +691,13 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF, // Handle the nasty case in that we duplicated a block that is part of a loop // into some but not all of its predecessors. For example: - // 1 -> 2 <-> 3 - // \ - // \---> rest + // 1 -> 2 <-> 3 | + // \ | + // \---> rest | // if we duplicate 2 into 1 but not into 3, we end up with - // 12 -> 3 <-> 2 -> rest - // \ / - // \----->-----/ + // 12 -> 3 <-> 2 -> rest | + // \ / | + // \----->-----/ | // If there was a "var = phi(1, 3)" in 2, it has to be ultimately replaced // with a phi in 3 (which now dominates 2). // What we do here is introduce a copy in 3 of the register defined by the