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});

	{ALODSL, ynone, Px, opBytes{0xad}},
	{ALODSQ, ynone, Pw, opBytes{0xad}},
	{ALODSW, ynone, Pe, opBytes{0xad}},
	{ALONG, ybyte, Px, opBytes{4}},
	{ALOOP, yloop, Px, opBytes{0xe2}},
	{ALOOPEQ, yloop, Px, opBytes{0xe1}},
	{ALOOPNE, yloop, Px, opBytes{0xe0}},
	{ALTR, ydivl, Pm, opBytes{0x00, 03}},
	{ALZCNTL, yml_rl, Pf3, opBytes{0xbd}},
	{ALZCNTQ, yml_rl, Pfw, opBytes{0xbd}},

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.

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

//go:build unix && !dragonfly && !freebsd && !netbsd

package unix

import "syscall"

// POSIX.1-2008 says it's ELOOP. Most platforms follow:
//
//   - aix: O_NOFOLLOW not documented (https://www.ibm.com/docs/ssw_aix_73/o_bostechref/open.html), assuming ELOOP
//   - android: see linux
//   - darwin: https://github.com/apple/darwin-xnu/blob/main/bsd/man/man2/open.2

				}
				i++
			}
			if i != 4 {
				t.Fatalf("should loop four times")
			}
		}},
		{"int8", ValueOf(int8(4)), func(t *testing.T, s iter.Seq[Value]) {
			i := int8(0)
			for v := range s {
				if v.Interface().(int8) != i {
					t.Fatalf("got %d, want %d", v.Int(), i)
				}
				i++
			}
			if i != 4 {
				t.Fatalf("should loop four times")
			}
		}},

// For best code generation, RF_DONE and RF_READY should be 0 and 1.
const (
	RF_DONE          = RF_State(iota) // body of loop has exited in a non-panic way
	RF_READY                          // body of loop has not exited yet, is not running  -- this is not a panic index
	RF_PANIC                          // body of loop is either currently running, or has panicked
	RF_EXHAUSTED                      // iterator function return, i.e., sequence is "exhausted"

	// R5 = b_len
	// R6 = b_cap (unused)
	// R7 = byte to find
	AND	$0xff, R7
	MOVV	R4, R6		// store base for later
	ADDV	R4, R5		// end
	ADDV	$-1, R4

	PCALIGN	$16
loop:
	ADDV	$1, R4
	BEQ	R4, R5, notfound
	MOVBU	(R4), R8
	BNE	R7, R8, loop

	SUBV	R6, R4		// remove base
	RET

notfound:
	MOVV	$-1, R4
	RET

TEXT ·IndexByteString<ABIInternal>(SB),NOSPLIT,$0-32
	// R4 = s_base
	// R5 = s_len

	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]