// license that can be found in the LICENSE file.

package ssa

import (
	"cmd/compile/internal/types"
	"fmt"
)

// an edgeMem records a backedge, together with the memory
// phi functions at the target of the backedge that must
// be updated when a rescheduling check replaces the backedge.
type edgeMem struct {
	e Edge
	m *Value // phi for memory at dest of e
}

// a rewriteTarget is a value-argindex pair indicating

    auto next_iteration =
        ops::NextIteration(scope.WithOpName("while/NextIteration"), add);

    auto sink = ops::Identity(scope.WithOpName("sink"), exit);

    // Remove the dummy node and add the loop backedge.
    scope.graph()->RemoveNode(dummy.node());
    scope.graph()->AddEdge(next_iteration.node(), 0, merge.output.node(), 1);

    TF_EXPECT_OK(scope.ToGraph(&graph));
  }

  GraphShapeInfo shape_info;

			} else if len(b.Succs) == 2 {
				// If successor is an unvisited backedge, it's in loop and we don't care.
				// Its default unlikely is also zero which is consistent with favoring loop edges.
				// Notice that this can act like a "reset" on unlikeliness at loops; the
				// default "everything returns" unlikeliness is erased by min with the
				// backedge likeliness; however a loop with calls on every path will be

}

Status PropagateShapes(Graph* graph,
                       const std::map<int, InferredShape>& arg_shapes,
                       const std::vector<BackEdgeHelper::BackEdge>& back_edges,
                       ShapeRefiner* shape_refiner) {
  std::map<const Node*, const Node*> merge_to_next_iteration;
  for (const auto& e : back_edges) {
    if (e.src->IsNextIteration() && e.dst->IsMerge()) {