return HashBorrower{pool: &s.HasherPool, borrowed: make([]hash.Hash, 0, 2)}
}

// HashBorrower keeps track of borrowed hashers and allows to return them all.
type HashBorrower struct {
	pool     *sync.Pool
	borrowed []hash.Hash
}

// Borrow a single hasher.
func (h *HashBorrower) Borrow() hash.Hash {
	hasher := h.pool.Get().(hash.Hash)
	h.borrowed = append(h.borrowed, hasher)
	hasher.Reset()
	return hasher
}

	return
}

// --- Subtract with borrow ---

// Sub returns the difference of x, y and borrow: diff = x - y - borrow.
// The borrow input must be 0 or 1; otherwise the behavior is undefined.
// The borrowOut output is guaranteed to be 0 or 1.
//
// This function's execution time does not depend on the inputs.
func Sub(x, y, borrow uint) (diff, borrowOut uint) {
	if UintSize == 32 {

	}

	// Perform a subtraction with borrow.
	var borrow uint64
	for i := 0; i < len(bufA); i += 8 {
		limbA, limbB := byteorder.LeUint64(bufA[i:]), byteorder.LeUint64(bufB[i:])
		_, borrow = bits.Sub64(limbA, limbB, borrow)
	}

	// If there is a borrow at the end of the operation, then a < b.
	return borrow == 1
}

}

// not returns the bitwise NOT of u.
func (u uint128) not() uint128 {
	return uint128{^u.hi, ^u.lo}
}

// subOne returns u - 1.
func (u uint128) subOne() uint128 {
	lo, borrow := bits.Sub64(u.lo, 1, 0)
	return uint128{u.hi - borrow, lo}
}

// addOne returns u + 1.
func (u uint128) addOne() uint128 {
	lo, carry := bits.Add64(u.lo, 1, 0)
	return uint128{u.hi + carry, lo}
}

loopOverEachWord:
	BRC  $3, copySetup    // no borrow, copy the rest
	MOVD 0(R6)(R12*1), R9

	// Originally we used the borrow flag generated in the previous iteration
	// (i.e: SUBE could be used here to do the subtraction). However, since we
	// already know borrow is 1 (otherwise we will go to copy section), we can
	// use SUBC here so the current iteration does not depend on the borrow flag

	"borrowingLimitPercent":    "`borrowingLimitPercent`, if present, configures a limit on how many seats this priority level can borrow from other priority levels. The limit is known as this level's BorrowingConcurrencyLimit (BorrowingCL) and is a limit on the total number of seats that this level may borrow at any one time. This field holds the ratio of that limit to the level's nominal concurrency limit. When this field is non-nil, it must hold a non-negative integer and the limit is calculated...

// branch on borrow
(C(G|LG)IJ {s390x.Equal}         (NEG (Select0 (SUBE (MOVDconst [0]) (MOVDconst [0]) borrow))) [0]) => (BRC {s390x.NoBorrow} borrow)
(C(G|LG)IJ {s390x.Equal}         (NEG (Select0 (SUBE (MOVDconst [0]) (MOVDconst [0]) borrow))) [1]) => (BRC {s390x.Borrow}   borrow)
(C(G|LG)IJ {s390x.LessOrGreater} (NEG (Select0 (SUBE (MOVDconst [0]) (MOVDconst [0]) borrow))) [0]) => (BRC {s390x.Borrow}   borrow)

  // `borrowingLimitPercent`, if present, configures a limit on how many
  // seats this priority level can borrow from other priority levels.
  // The limit is known as this level's BorrowingConcurrencyLimit
  // (BorrowingCL) and is a limit on the total number of seats that this
  // level may borrow at any one time.
  // This field holds the ratio of that limit to the level's nominal

	LendablePercent *int32

	// `borrowingLimitPercent`, if present, configures a limit on how many
	// seats this priority level can borrow from other priority levels.
	// The limit is known as this level's BorrowingConcurrencyLimit
	// (BorrowingCL) and is a limit on the total number of seats that this
	// level may borrow at any one time.
	// This field holds the ratio of that limit to the level's nominal

	"borrowingLimitPercent":    "`borrowingLimitPercent`, if present, configures a limit on how many seats this priority level can borrow from other priority levels. The limit is known as this level's BorrowingConcurrencyLimit (BorrowingCL) and is a limit on the total number of seats that this level may borrow at any one time. This field holds the ratio of that limit to the level's nominal concurrency limit. When this field is non-nil, it must hold a non-negative integer and the limit is calculated...