Sub_BNU

Subtracts one integer big number from another integer big number of the same length.

Syntax

IppStatus ippsSub_BNU(const Ipp32u *a, const Ipp32u *b, Ipp32u *r, int n, Ipp32u * carry);

Parameters

a	First unsigned integer big number of n*32 bits.
b	Second unsigned integer big number of n*32 bits.
n	Size specified for the input parameters a and b and the result parameter r. The size is expressed in the number of 32-bit words.
r	Subtraction result.
carry	Subtraction borrow. Possible value is 0 or 1.

Description

This function is declared in the ippcp.h file. The function subtracts one integer big number from another big-number integer of the same length and returns the result of the operation with a possible borrow returned as the carry argument.

The following pseudocode represents this function:

(*r) ← (*a) - (*b);

carry = ((*a) < (*b)).

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or warning.
ippStsNullPtrErr	Indicates an error condition if any of the specified pointers is NULL.
ippStsLengthErr	Indicates an error condition if n is less than or equal to 0.