示例#1
0
ACPI_STATUS
AcpiUtDivide (
    UINT64                  InDividend,
    UINT64                  InDivisor,
    UINT64                  *OutQuotient,
    UINT64                  *OutRemainder)
{
    UINT64_OVERLAY          Dividend;
    UINT64_OVERLAY          Divisor;
    UINT64_OVERLAY          Quotient;
    UINT64_OVERLAY          Remainder;
    UINT64_OVERLAY          NormalizedDividend;
    UINT64_OVERLAY          NormalizedDivisor;
    UINT32                  Partial1;
    UINT64_OVERLAY          Partial2;
    UINT64_OVERLAY          Partial3;


    ACPI_FUNCTION_TRACE (UtDivide);


    /* Always check for a zero divisor */

    if (InDivisor == 0)
    {
        ACPI_ERROR ((AE_INFO, "Divide by zero"));
        return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
    }

    Divisor.Full  = InDivisor;
    Dividend.Full = InDividend;
    if (Divisor.Part.Hi == 0)
    {
        /*
         * 1) Simplest case is where the divisor is 32 bits, we can
         * just do two divides
         */
        Remainder.Part.Hi = 0;

        /*
         * The quotient is 64 bits, the remainder is always 32 bits,
         * and is generated by the second divide.
         */
        ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo,
                           Quotient.Part.Hi, Partial1);
        ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo,
                           Quotient.Part.Lo, Remainder.Part.Lo);
    }

    else
    {
        /*
         * 2) The general case where the divisor is a full 64 bits
         * is more difficult
         */
        Quotient.Part.Hi   = 0;
        NormalizedDividend = Dividend;
        NormalizedDivisor  = Divisor;

        /* Normalize the operands (shift until the divisor is < 32 bits) */

        do
        {
            ACPI_SHIFT_RIGHT_64 (NormalizedDivisor.Part.Hi,
                                 NormalizedDivisor.Part.Lo);
            ACPI_SHIFT_RIGHT_64 (NormalizedDividend.Part.Hi,
                                 NormalizedDividend.Part.Lo);

        } while (NormalizedDivisor.Part.Hi != 0);

        /* Partial divide */

        ACPI_DIV_64_BY_32 (NormalizedDividend.Part.Hi,
                           NormalizedDividend.Part.Lo,
                           NormalizedDivisor.Part.Lo,
                           Quotient.Part.Lo, Partial1);

        /*
         * The quotient is always 32 bits, and simply requires adjustment.
         * The 64-bit remainder must be generated.
         */
        Partial1      = Quotient.Part.Lo * Divisor.Part.Hi;
        Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo;
        Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1;

        Remainder.Part.Hi = Partial3.Part.Lo;
        Remainder.Part.Lo = Partial2.Part.Lo;

        if (Partial3.Part.Hi == 0)
        {
            if (Partial3.Part.Lo >= Dividend.Part.Hi)
            {
                if (Partial3.Part.Lo == Dividend.Part.Hi)
                {
                    if (Partial2.Part.Lo > Dividend.Part.Lo)
                    {
                        Quotient.Part.Lo--;
                        Remainder.Full -= Divisor.Full;
                    }
                }
                else
                {
                    Quotient.Part.Lo--;
                    Remainder.Full -= Divisor.Full;
                }
            }

            Remainder.Full    = Remainder.Full - Dividend.Full;
            Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi);
            Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo);

            if (Remainder.Part.Lo)
            {
                Remainder.Part.Hi--;
            }
        }
    }

    /* Return only what was requested */

    if (OutQuotient)
    {
        *OutQuotient = Quotient.Full;
    }
    if (OutRemainder)
    {
        *OutRemainder = Remainder.Full;
    }

    return_ACPI_STATUS (AE_OK);
}
示例#2
0
文件: utmath.c 项目: 274914765/C
acpi_status
acpi_ut_divide(acpi_integer in_dividend,
           acpi_integer in_divisor,
           acpi_integer * out_quotient, acpi_integer * out_remainder)
{
    union uint64_overlay dividend;
    union uint64_overlay divisor;
    union uint64_overlay quotient;
    union uint64_overlay remainder;
    union uint64_overlay normalized_dividend;
    union uint64_overlay normalized_divisor;
    u32 partial1;
    union uint64_overlay partial2;
    union uint64_overlay partial3;

    ACPI_FUNCTION_TRACE(ut_divide);

    /* Always check for a zero divisor */

    if (in_divisor == 0) {
        ACPI_ERROR((AE_INFO, "Divide by zero"));
        return_ACPI_STATUS(AE_AML_DIVIDE_BY_ZERO);
    }

    divisor.full = in_divisor;
    dividend.full = in_dividend;
    if (divisor.part.hi == 0) {
        /*
         * 1) Simplest case is where the divisor is 32 bits, we can
         * just do two divides
         */
        remainder.part.hi = 0;

        /*
         * The quotient is 64 bits, the remainder is always 32 bits,
         * and is generated by the second divide.
         */
        ACPI_DIV_64_BY_32(0, dividend.part.hi, divisor.part.lo,
                  quotient.part.hi, partial1);
        ACPI_DIV_64_BY_32(partial1, dividend.part.lo, divisor.part.lo,
                  quotient.part.lo, remainder.part.lo);
    }

    else {
        /*
         * 2) The general case where the divisor is a full 64 bits
         * is more difficult
         */
        quotient.part.hi = 0;
        normalized_dividend = dividend;
        normalized_divisor = divisor;

        /* Normalize the operands (shift until the divisor is < 32 bits) */

        do {
            ACPI_SHIFT_RIGHT_64(normalized_divisor.part.hi,
                        normalized_divisor.part.lo);
            ACPI_SHIFT_RIGHT_64(normalized_dividend.part.hi,
                        normalized_dividend.part.lo);

        } while (normalized_divisor.part.hi != 0);

        /* Partial divide */

        ACPI_DIV_64_BY_32(normalized_dividend.part.hi,
                  normalized_dividend.part.lo,
                  normalized_divisor.part.lo,
                  quotient.part.lo, partial1);

        /*
         * The quotient is always 32 bits, and simply requires adjustment.
         * The 64-bit remainder must be generated.
         */
        partial1 = quotient.part.lo * divisor.part.hi;
        partial2.full =
            (acpi_integer) quotient.part.lo * divisor.part.lo;
        partial3.full = (acpi_integer) partial2.part.hi + partial1;

        remainder.part.hi = partial3.part.lo;
        remainder.part.lo = partial2.part.lo;

        if (partial3.part.hi == 0) {
            if (partial3.part.lo >= dividend.part.hi) {
                if (partial3.part.lo == dividend.part.hi) {
                    if (partial2.part.lo > dividend.part.lo) {
                        quotient.part.lo--;
                        remainder.full -= divisor.full;
                    }
                } else {
                    quotient.part.lo--;
                    remainder.full -= divisor.full;
                }
            }

            remainder.full = remainder.full - dividend.full;
            remainder.part.hi = (u32) - ((s32) remainder.part.hi);
            remainder.part.lo = (u32) - ((s32) remainder.part.lo);

            if (remainder.part.lo) {
                remainder.part.hi--;
            }
        }
    }

    /* Return only what was requested */

    if (out_quotient) {
        *out_quotient = quotient.full;
    }
    if (out_remainder) {
        *out_remainder = remainder.full;
    }

    return_ACPI_STATUS(AE_OK);
}
acpi_status
acpi_ut_divide(u64 in_dividend,
	       u64 in_divisor, u64 *out_quotient, u64 *out_remainder)
{
	union uint64_overlay dividend;
	union uint64_overlay divisor;
	union uint64_overlay quotient;
	union uint64_overlay remainder;
	union uint64_overlay normalized_dividend;
	union uint64_overlay normalized_divisor;
	u32 partial1;
	union uint64_overlay partial2;
	union uint64_overlay partial3;

	ACPI_FUNCTION_TRACE(ut_divide);

	

	if (in_divisor == 0) {
		ACPI_ERROR((AE_INFO, "Divide by zero"));
		return_ACPI_STATUS(AE_AML_DIVIDE_BY_ZERO);
	}

	divisor.full = in_divisor;
	dividend.full = in_dividend;
	if (divisor.part.hi == 0) {
		remainder.part.hi = 0;

		ACPI_DIV_64_BY_32(0, dividend.part.hi, divisor.part.lo,
				  quotient.part.hi, partial1);
		ACPI_DIV_64_BY_32(partial1, dividend.part.lo, divisor.part.lo,
				  quotient.part.lo, remainder.part.lo);
	}

	else {
		quotient.part.hi = 0;
		normalized_dividend = dividend;
		normalized_divisor = divisor;

		

		do {
			ACPI_SHIFT_RIGHT_64(normalized_divisor.part.hi,
					    normalized_divisor.part.lo);
			ACPI_SHIFT_RIGHT_64(normalized_dividend.part.hi,
					    normalized_dividend.part.lo);

		} while (normalized_divisor.part.hi != 0);

		

		ACPI_DIV_64_BY_32(normalized_dividend.part.hi,
				  normalized_dividend.part.lo,
				  normalized_divisor.part.lo,
				  quotient.part.lo, partial1);

		partial1 = quotient.part.lo * divisor.part.hi;
		partial2.full = (u64) quotient.part.lo * divisor.part.lo;
		partial3.full = (u64) partial2.part.hi + partial1;

		remainder.part.hi = partial3.part.lo;
		remainder.part.lo = partial2.part.lo;

		if (partial3.part.hi == 0) {
			if (partial3.part.lo >= dividend.part.hi) {
				if (partial3.part.lo == dividend.part.hi) {
					if (partial2.part.lo > dividend.part.lo) {
						quotient.part.lo--;
						remainder.full -= divisor.full;
					}
				} else {
					quotient.part.lo--;
					remainder.full -= divisor.full;
				}
			}

			remainder.full = remainder.full - dividend.full;
			remainder.part.hi = (u32) - ((s32) remainder.part.hi);
			remainder.part.lo = (u32) - ((s32) remainder.part.lo);

			if (remainder.part.lo) {
				remainder.part.hi--;
			}
		}
	}

	

	if (out_quotient) {
		*out_quotient = quotient.full;
	}
	if (out_remainder) {
		*out_remainder = remainder.full;
	}

	return_ACPI_STATUS(AE_OK);
}