// is (x | y), and a carry from the lower place happened. If such a carry
	// happens, the top bit will be 1 + 0 + 1 = 0 (&^ sum).
	carryOut = ((x & y) | ((x | y) &^ sum)) >> 63
	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.
//

			lastTrim := time.Unix(t, 0)
			if d := now.Sub(lastTrim); d < trimInterval && d > -mtimeInterval {
				return nil
			}
		}
	}

	// Trim each of the 256 subdirectories.
	// We subtract an additional mtimeInterval
	// to account for the imprecision of our "last used" mtimes.
	cutoff := now.Add(-trimLimit - mtimeInterval)
	for i := 0; i < 256; i++ {
		subdir := filepath.Join(c.dir, fmt.Sprintf("%02x", i))

type p256OrdElement [4]uint64

// p256OrdReduce ensures s is in the range [0, ord(G)-1].
func p256OrdReduce(s *p256OrdElement) {
	// Since 2 * ord(G) > 2²⁵⁶, we can just conditionally subtract ord(G),
	// keeping the result if it doesn't underflow.
	t0, b := bits.Sub64(s[0], 0xf3b9cac2fc632551, 0)
	t1, b := bits.Sub64(s[1], 0xbce6faada7179e84, b)
	t2, b := bits.Sub64(s[2], 0xffffffffffffffff, b)

			accessor.SetNamespace(namespace)
		}
	}
	// there is at least one quota that definitely matches our object
	// as a result, we need to measure the usage of this object for quota
	// on updates, we need to subtract the previous measured usage
	// if usage shows no change, just return since it has no impact on quota
	deltaUsage, err := evaluator.Usage(inputObject)
	if err != nil {
		return quotas, err
	}

			default:
				opcode = OPCODE_BASE + LINE_RANGE*PC_RANGE - 1 // 249
			}
		}
	}
	if opcode < OPCODE_BASE || opcode > 255 {
		panic(fmt.Sprintf("produced invalid special opcode %d", opcode))
	}

	// Subtract from deltaPC and deltaLC the amounts that the opcode will add.
	deltaPC -= uint64((opcode - OPCODE_BASE) / LINE_RANGE)
	deltaLC -= (opcode-OPCODE_BASE)%LINE_RANGE + LINE_BASE

	// Encode deltaPC.
	if deltaPC != 0 {

	if b.err != nil {
		return
	}

	b.AddASN1(asn1.INTEGER, func(c *Builder) {
		if n.Sign() < 0 {
			// A negative number has to be converted to two's-complement form. So we
			// invert and subtract 1. If the most-significant-bit isn't set then
			// we'll need to pad the beginning with 0xff in order to keep the number
			// negative.
			nMinus1 := new(big.Int).Neg(n)
			nMinus1.Sub(nMinus1, bigOne)

	MOVD z+0(FP), R8
	MOVD $0, R0          // R0 is a temporary variable used during computation. Ensure it has zero in it.

	CMPBEQ R5, $0, returnC // len(z) == 0, have an early return

	// Subtract the first two words, and determine which path (copy path or loop path) to take based on the borrow flag
	MOVD   0(R6), R9
	SUBC   R7, R9
	MOVD   R9, 0(R8)
	CMPBEQ R5, $1, returnResult
	MOVD   8(R6), R9

	/* Vector subtract */
	{as: AVSUBUM, a1: C_VREG, a2: C_VREG, a6: C_VREG, type_: 82, size: 4},            /* vector subtract unsigned modulo, vx-form */
	{as: AVSUBCU, a1: C_VREG, a2: C_VREG, a6: C_VREG, type_: 82, size: 4},            /* vector subtract & write carry unsigned, vx-form */
	{as: AVSUBUS, a1: C_VREG, a2: C_VREG, a6: C_VREG, type_: 82, size: 4},            /* vector subtract unsigned saturate, vx-form */

				//
				// However, if UtilPerProc isn't set, then we probably have data from other procs
				// and from previous events. We need to fix that up.
				if flags&UtilPerProc != 0 {
					break
				}
				// Subtract out 1/gomaxprocs mutator utilization for all time periods
				// from the beginning of the trace until now.
				mi, pi := 0, 0
				for mi < len(out[0]) {
					if pi < len(procs)-1 && procs[pi+1].time < out[0][mi].Time {

			// so we check for this before we read the 16-bit length of the segment.
			continue
		}

		// Read the 16-bit length of the segment. The value includes the 2 bytes for the
		// length itself, so we subtract 2 to get the number of remaining bytes.
		if err = d.readFull(d.tmp[:2]); err != nil {
			return nil, err
		}
		n := int(d.tmp[0])<<8 + int(d.tmp[1]) - 2
		if n < 0 {