auto enter =
        ops::internal::Enter(scope.WithOpName("while/Enter"), source, "aloop");
    // Add an unused Enter node. These should be ignored.
    auto enter2 =
        ops::internal::Enter(scope.WithOpName("while/Enter2"), source, "aloop");
    auto merge = ops::Merge(scope.WithOpName("while/Merge"),
                            std::initializer_list<Input>{enter, dummy});

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

	CMP   R5, $0
	MOVD  R5, CTR         // Set up loop counter
	BEQ   tail            // If R5 = 0, we can't use the loop

	// Process 4 elements per iteration. Unrolling this loop
	// means a performance trade-off: we will lose performance
	// for small values of z_len (0.90x in the worst case), but
	// gain significant performance as z_len increases (up to
	// 1.45x).

	PCALIGN $16
loop:
	MOVD  8(R8), R11      // R11 = x[i]

        max_concurrent 1000
    }
    cache 30
    loop
    reload
    loadbalance
}
`,
			coreDNSVersion: "1.6.2",
		},
		{
			name: "Default Corefile with rearranged plugins",
			initialCorefileData: `.:53 {
        errors
        cache 30
        prometheus :9153
        forward . /etc/resolv.conf
        loop
        reload
        loadbalance

	// When not surging, we delete just enough pods to stay under the maxUnavailable limit, if any
	// are necessary, and let the core loop create new instances on those nodes.
	//
	// Assumptions:
	// * Expect manage loop to allow no more than one pod per node
	// * Expect manage loop will create new pods
	// * Expect manage loop will handle failed pods
	// * Deleted pods do not count as unavailable so that updates make progress when nodes are down

	HotPgoInitial          = HotPgo | HotInitial                // special case; single block loop, initial block is header block has a flow-in entry, but PGO says it is hot
	HotPgoInitialNotFLowIn = HotPgo | HotInitial | HotNotFlowIn // PGO says it is hot, and the loop is rotated so flow enters loop with a branch

            }
          }
        }
      }
    }

    // Merge node causes a loop so we remove NextIteration->Merge edge before
    // performing shape inference. But removing those edges also prevents us
    // from inferring output shape for Merge node (we need shapes for all its
    // inputs).
    // For loop invariant resource input's Merge node, we set output resource
    // shape as Enter node's resource shape.

	// Eliminate bounds checks in the loop.
	size := len(x.limbs)
	xLimbs := x.limbs[:size]
	yLimbs := y.limbs[:size]

	equal := yes
	for i := 0; i < size; i++ {
		equal &= ctEq(xLimbs[i], yLimbs[i])
	}
	return equal
}

// IsZero returns 1 if x == 0, and 0 otherwise.
func (x *Nat) IsZero() choice {
	// Eliminate bounds checks in the loop.
	size := len(x.limbs)
	xLimbs := x.limbs[:size]

// Analyzes while loops to compute resourceIDs for the loop results.
//
// (1) The base case for the analysis is that if the loop body does not execute
//     at all, the resource IDs for each result is the same as the resource IDs
//     of the corresponding input.
// (2) If the loop does execute one or more times, then we need to account for
//     data flow through the body of the while loop. If result #r is the same

var rangePanicError = error(errorString("range function continued iteration after loop body panic"))
var rangeExhaustedError = error(errorString("range function continued iteration after whole loop exit"))
var rangeMissingPanicError = error(errorString("range function recovered a loop body panic and did not resume panicking"))

//go:noinline