package ssa

// loopRotate converts loops with a check-loop-condition-at-beginning
// to loops with a check-loop-condition-at-end.
// This helps loops avoid extra unnecessary jumps.
//
//	 loop:
//	   CMPQ ...
//	   JGE exit
//	   ...
//	   JMP loop
//	 exit:
//
//	  JMP entry
//	loop:
//	  ...
//	entry:
//	  CMPQ ...
//	  JLT loop
func loopRotate(f *Func) {
	loopnest := f.loopnest()

  for (int i = 0; i < n; ++i) result.push_back(ToOutput(output_tensors[i]));
  return result;
}

// The backprop loop counter and main backprop loop run in their own execution
// frame (conceptually, the main forward loop and forward loop counter run
// together in a frame, then the backprop loop counter and backprop loop run
// together in a different frame). This returns the frame name to use for the
// backprop while loops.

// CHECK-LABEL: func @preserve_unreachable_tpu_replicate_metadata
func.func @preserve_unreachable_tpu_replicate_metadata() {
  tf_executor.graph {
    %0 = tf_executor.ControlTrigger {}
    // CHECK: "tf.NoOp"
    %1 = tf_executor.island wraps "tf.NoOp"() : () -> ()
    // CHECK: "tf.TPUReplicateMetadata"

        code << [
                "id('noop')",
                "id 'noop'",
                "id('noop').version('bar')",
                "id 'noop' version 'bar'",
                "id('noop').\nversion 'bar'",
                "id('java');id('noop')",
                "id('java')\nid('noop')",
                "id('noop').version('bar');id('java')",
                "id('noop').version('bar')\nid('java')",

// Package loopclosure defines an Analyzer that checks for references to
// enclosing loop variables from within nested functions.
//
// # Analyzer loopclosure
//
// loopclosure: check references to loop variables from within nested functions
//
// This analyzer reports places where a function literal references the
// iteration variable of an enclosing loop, and the loop calls the function
// in such a way (e.g. with go or defer) that it may outlive the loop

package escape

var x bool

func f1() {
	var p *int
loop:
	if x {
		goto loop
	}
	// BAD: We should be able to recognize that there
	// aren't any more "goto loop" after here.
	p = new(int) // ERROR "escapes to heap"
	_ = p
}

func f2() {
	var p *int
	if x {
	loop:
		goto loop
	} else {
		p = new(int) // ERROR "does not escape"
	}
	_ = p
}

func f3() {

it does not call the loop body again after it has returned false or
after the entire loop has exited (it might retain a copy of the body
function, or pass it to another goroutine) -- each generated loop has
its own #stateK variable that is used to check for permitted call
patterns to the yield function for a loop body.

The state values are:

abi.RF_DONE = 0      // body of loop has exited in a non-panic way

        //   ApplyWeightUpdates_1 -> Computation_B
        //   ApplyWeightUpdates_2 -> Computation_C
        //   Computation_A -> NoOp
        //   Computation_B -> NoOp
        //   Computation_C -> NoOp
        //   "iteration++" -> NoOp
        // }
        //
        // In the graph above we can't cluster iteration++ with any of the

		for i := 0; i < x; i++ { // ERROR "Branch prediction rule stay in loop"
			if x == 4 { // ERROR "Branch prediction rule stay in loop"
				return a
			}
			for j := 0; j < y; j++ { // ERROR "Branch prediction rule stay in loop"
				for k := 0; k < z; k++ { // ERROR "Branch prediction rule stay in loop"
					a -= j * i
				}
				a += j
			}
		}
	}
	return a
}

// Checks that 2 `NoOp`s having control dependencies to each of the initializer
// functions are created.
// CHECK-DAG: %[[CTL_2:.*]] = tf_executor.island(%[[CTL_0]]) wraps "tf.NoOp"()
// CHECK-DAG: %[[CTL_3:.*]] = tf_executor.island(%[[CTL_1]]) wraps "tf.NoOp"()

// CHECK: tf_executor.fetch
// CHECK-SAME: !tf_executor.control, !tf_executor.control