__rt_div_worker.h File Reference

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Classes
union	_ARM_DIVRESULT

Typedefs
typedef unsigned int	UINT3264
typedef int	INT3264
typedef unsigned long long	RETURN_TYPE
typedef union _ARM_DIVRESULT	ARM_DIVRESULT

Functions
__forceinline void	__brkdiv0 (void)
RETURN_TYPE	__rt_div_worker (UINT3264 divisor, UINT3264 dividend)

Typedef Documentation

ARM_DIVRESULT

typedef union _ARM_DIVRESULT ARM_DIVRESULT

INT3264

typedef int INT3264

Definition at line 31 of file __rt_div_worker.h.

RETURN_TYPE

typedef unsigned long long RETURN_TYPE

Definition at line 32 of file __rt_div_worker.h.

UINT3264

typedef unsigned int UINT3264

Definition at line 30 of file __rt_div_worker.h.

Function Documentation

__brkdiv0()

__forceinline void __brkdiv0

(

void

)

Definition at line 37 of file __rt_div_worker.h.

{
    __emit(0xDEF9);
}

Referenced by __rt_div_worker().

__rt_div_worker()

RETURN_TYPE __rt_div_worker	(	UINT3264	divisor,
		UINT3264	dividend
	)

Definition at line 53 of file __rt_div_worker.h.

{
    ARM_DIVRESULT result;
    UINT3264 shift;
    UINT3264 mask;
    UINT3264 quotient;
#ifdef _SIGNED_DIV_
    int dividend_sign = 0;
    int divisor_sign = 0;
#endif // _SIGNED_DIV_
 
    if (divisor == 0)
    {
        /* Raise divide by zero error */
        __brkdiv0();
    }
 
#ifdef _SIGNED_DIV_
    if ((INT3264)dividend < 0)
    {
        dividend_sign = 1;
        dividend = -(INT3264)dividend;
    }
 
    if ((INT3264)divisor < 0)
    {
        divisor_sign = 1;
        divisor = -(INT3264)divisor;
    }
#endif // _SIGNED_DIV_
 
    if (divisor > dividend)
    {
        result.data.quotient = 0;
#ifdef _SIGNED_DIV_
        if (dividend_sign)
            dividend = -(INT3264)dividend;
#endif // _SIGNED_DIV_
        result.data.modulus = dividend;
        return result.raw_data;
    }
 
    /* Get the difference in count of leading zeros between dividend and divisor */
    shift = _CountLeadingZeros(divisor);
    shift -= _CountLeadingZeros(dividend);
 
    /* Shift the divisor to the left, so that it's highest bit is the same
       as the highest bit of the dividend */
    divisor <<= shift;
 
    mask = (UINT3264)1 << shift;
 
    quotient = 0;
    do
    {
        if (dividend >= divisor)
        {
            quotient |= mask;
            dividend -= divisor;
        }
        divisor >>= 1;
        mask >>= 1;
    }
    while (mask);
 
#ifdef _SIGNED_DIV_
    if (dividend_sign ^ divisor_sign)
    {
        quotient = -(INT3264)quotient;
    }
 
    if (dividend_sign)
    {
        dividend = -(INT3264)dividend;
    }
#endif // _SIGNED_DIV_
 
    result.data.quotient = quotient;
    result.data.modulus = dividend;
    return result.raw_data;
}