// come right after it.
	after := map[ID][]*Block{}

	// Check each loop header and decide if we want to move it.
	for _, loop := range loopnest.loops {
		b := loop.header
		var p *Block // b's in-loop predecessor
		for _, e := range b.Preds {
			if e.b.Kind != BlockPlain {
				continue
			}
			if loopnest.b2l[e.b.ID] != loop {
				continue
			}
			p = e.b
		}
		if p == nil {
			continue
		}

                      Iterators.transform(
                          graph.predecessors(node).iterator(),
                          (N predecessor) -> EndpointPair.ordered(predecessor, node)),
                      Iterators.transform(
                          // filter out 'node' from successors (already covered by predecessors,
                          // above)

		for p := range n.pred {
			// ignore self-cycles
			if p != n {
				// Each successor s of n becomes a successor of p, and
				// each predecessor p of n becomes a predecessor of s.
				for s := range n.succ {
					// ignore self-cycles
					if s != n {
						p.succ.add(s)
						s.pred.add(p)
					}
				}
				delete(p.succ, n) // remove edge to n
			}
		}

		for p := range n.pred {
			// ignore self-cycles
			if p != n {
				// Each successor s of n becomes a successor of p, and
				// each predecessor p of n becomes a predecessor of s.
				for s := range n.succ {
					// ignore self-cycles
					if s != n {
						p.succ.add(s)
						s.pred.add(p)
					}
				}
				delete(p.succ, n) // remove edge to n
			}
		}

                                       &arg)
                    .succeeded()) {
              options.insert(arg);
            }
          }
        } else {
          op->emitOpError("Predecessor op doesn't implement BranchOpInterface");
          return failure();
        }
      }
    }
    if (!options.empty()) {
      if (options.size() != 1) {
        op->emitOpError("Incompatible code paths.");

			change = true
		}
		if change {
			ranges[i] = lp
		}
	}

	// Visit in reverse post order so that all non-loop predecessors come first.
	for j := len(po) - 1; j >= 0; j-- {
		b := po[j]
		// Find the first interesting position and check to see if it differs from any predecessor
		firstPos := src.NoXPos
		firstPosIndex := -1
		if b.Pos.IsStmt() != src.PosNotStmt {
			note(b.Pos)
		}

    while (op && op != func) {
      op->removeAttr("_is_compilation");
      op->removeAttr("_wraps_compilation");
      op = op->getParentOp();
    }
  });
}

int OutsideCompilationOrdering(Operation* predecessor, Operation* op) {
  // Actual compilations go first.
  if (op->hasAttr("_is_compilation")) return 2;
  // Followed by nested ops that contain compilations.
  if (op->hasAttr("_wraps_compilation")) return 1;

    }
  }
  return successors;
}
// Gets the predecessors of an op wrapped in tf_executor.island.
llvm::SmallVector<Operation*> GetPredecessors(Operation* op) {
  llvm::SmallVector<Operation*> predecessors;
  for (auto operand : op->getOperands()) {
    if (Operation* pred = operand.getDefiningOp()) {
      pred->walk([&](mlir::Operation* opinexecutor) {
        predecessors.push_back(opinexecutor);
      });
    }
  }

// not be a predecessor.
//
// Note that mergePredecessors behaves slightly differently between
// first and subsequent calls for a block.  For the first call, the
// starting state is approximated by taking the state from the
// predecessor whose state is smallest, and removing any elements not
// in all the other predecessors; this makes the smallest number of

			// 2, Avoid the predecessor that contains the function call, because the predecessor that
			//    contains the function call usually generates a lot of spills and lose the previous
			//    allocation state.
			// TODO: Improve this part. At least the size of endRegs of the predecessor also has
			// an impact on the code size and compiler speed. But it is not easy to find a simple