stablehlo.return %3 : tensor<f32>
  }) {
    window_dimensions = array<i64: 1, 1, 2, 2>,
    window_strides = array<i64: 1, 1, 2, 2>,
    padding = dense<[[0, 0], [0, 0], [1, 1], [1, 1]]> : tensor<4x2xi64>
  } : (tensor<1x4x16x16xf32>, tensor<f32>) -> tensor<1x4x9x9xf32>
  return %2 : tensor<1x4x9x9xf32>
}
// CHECK-SAME: %[[ARG:.+]]: tensor<1x16x16x4xf32>
// CHECK-DAG: stablehlo.constant

const (
	surrogateMin = 0xD800
	surrogateMax = 0xDFFF
)

const (
	t1 = 0b00000000
	tx = 0b10000000
	t2 = 0b11000000
	t3 = 0b11100000
	t4 = 0b11110000
	t5 = 0b11111000

	maskx = 0b00111111
	mask2 = 0b00011111
	mask3 = 0b00001111
	mask4 = 0b00000111

	rune1Max = 1<<7 - 1
	rune2Max = 1<<11 - 1
	rune3Max = 1<<16 - 1

	// The default lowest and highest continuation byte.
	locb = 0b10000000

	return int(deBruijn64tab[(x&-x)*deBruijn64>>(64-6)])
}

// --- OnesCount ---

const m0 = 0x5555555555555555 // 01010101 ...
const m1 = 0x3333333333333333 // 00110011 ...
const m2 = 0x0f0f0f0f0f0f0f0f // 00001111 ...
const m3 = 0x00ff00ff00ff00ff // etc.
const m4 = 0x0000ffff0000ffff

// OnesCount returns the number of one bits ("population count") in x.
func OnesCount(x uint) int {
	if UintSize == 32 {