"F16",
	"F17",
	"F18",
	"F19",
	"F20",
	"F21",
	"F22",
	"F23",
	"F24",
	"F25",
	"F26",
	"F27",
	"F28",
	"F29",
	"F30",
	"F31",

	"HI", // high bits of multiplication
	"LO", // low bits of multiplication

	// If you add registers, update asyncPreempt in runtime.

	// pseudo-registers
	"SB",
}

func init() {
	// Make map from reg names to reg integers.

    double ySumOfSquaresOfDeltas = yStats.sumOfSquaresOfDeltas();
    checkState(xSumOfSquaresOfDeltas > 0.0);
    checkState(ySumOfSquaresOfDeltas > 0.0);
    // The product of two positive numbers can be zero if the multiplication underflowed. We
    // force a positive value by effectively rounding up to MIN_VALUE.
    double productOfSumsOfSquaresOfDeltas =
        ensurePositive(xSumOfSquaresOfDeltas * ySumOfSquaresOfDeltas);

    double ySumOfSquaresOfDeltas = yStats().sumOfSquaresOfDeltas();
    checkState(xSumOfSquaresOfDeltas > 0.0);
    checkState(ySumOfSquaresOfDeltas > 0.0);
    // The product of two positive numbers can be zero if the multiplication underflowed. We
    // force a positive value by effectively rounding up to MIN_VALUE.
    double productOfSumsOfSquaresOfDeltas =
        ensurePositive(xSumOfSquaresOfDeltas * ySumOfSquaresOfDeltas);

	//	R = Y' + 1.40200*(Cr-128)
	//	G = Y' - 0.34414*(Cb-128) - 0.71414*(Cr-128)
	//	B = Y' + 1.77200*(Cb-128)
	// https://www.w3.org/Graphics/JPEG/jfif3.pdf says Y but means Y'.
	//
	// Those formulae use non-integer multiplication factors. When computing,
	// integer math is generally faster than floating point math. We multiply
	// all of those factors by 1<<16 and round to the nearest integer:
	//	 91881 = roundToNearestInteger(1.40200 * 65536).

	AADDIW
	ASLLIW
	ASRLIW
	ASRAIW
	AADDW
	ASLLW
	ASRLW
	ASUBW
	ASRAW

	// 5.3: Load and Store Instructions (RV64I)
	ALD
	ASD

	// 7.1: Multiplication Operations
	AMUL
	AMULH
	AMULHU
	AMULHSU
	AMULW
	ADIV
	ADIVU
	AREM
	AREMU
	ADIVW
	ADIVUW
	AREMW
	AREMUW

	// 8.2: Load-Reserved/Store-Conditional Instructions

    double ySumOfSquaresOfDeltas = yStats().sumOfSquaresOfDeltas();
    checkState(xSumOfSquaresOfDeltas > 0.0);
    checkState(ySumOfSquaresOfDeltas > 0.0);
    // The product of two positive numbers can be zero if the multiplication underflowed. We
    // force a positive value by effectively rounding up to MIN_VALUE.
    double productOfSumsOfSquaresOfDeltas =
        ensurePositive(xSumOfSquaresOfDeltas * ySumOfSquaresOfDeltas);

	//
	// We want to compute
	// 	hi, lo := bits.Mul64(r.Uint64(), n)
	// In terms of 32-bit halves, this is:
	// 	x1:x0 := r.Uint64()
	// 	0:hi, lo1:lo0 := bits.Mul64(x1:x0, 0:n)
	// Writing out the multiplication in terms of bits.Mul32 allows
	// using direct hardware instructions and avoiding
	// the computations involving these zeros.
	x := r.Uint64()
	lo1a, lo0 := bits.Mul32(uint32(x), n)

	// hitting the cap). If not positive, the duration is not
	// changed. Used for exponential backoff in combination with
	// Factor and Cap.
	Steps int
	// A limit on revised values of the duration parameter. If a
	// multiplication by the factor parameter would make the duration
	// exceed the cap then the duration is set to the cap and the
	// steps parameter is set to zero.
	Cap time.Duration
}

	SRAW	$1, X6					// 1b531340

	// 5.3: Load and Store Instructions (RV64I)
	LD	(X5), X6				// 03b30200
	LD	4(X5), X6				// 03b34200
	SD	X5, (X6)				// 23305300
	SD	X5, 4(X6)				// 23325300

	// 7.1: Multiplication Operations
	MUL	X5, X6, X7				// b3035302
	MULH	X5, X6, X7				// b3135302
	MULHU	X5, X6, X7				// b3335302
	MULHSU	X5, X6, X7				// b3235302
	MULW	X5, X6, X7				// bb035302
	DIV	X5, X6, X7				// b3435302

    // Strip off 2s from this value.
    int shift = Long.numberOfTrailingZeros(product);
    product >>= shift;

    // Use floor(log2(num)) + 1 to prevent overflow of multiplication.
    int productBits = LongMath.log2(product, FLOOR) + 1;
    int bits = LongMath.log2(startingNumber, FLOOR) + 1;
    // Check for the next power of two boundary, to save us a CLZ operation.