# Vector SubtractionBasic Math Functions

## Functions

void arm_sub_f32 (float32_t *pSrcA, float32_t *pSrcB, float32_t *pDst, uint32_t blockSize)
Floating-point vector subtraction.

void arm_sub_q15 (q15_t *pSrcA, q15_t *pSrcB, q15_t *pDst, uint32_t blockSize)
Q15 vector subtraction.

void arm_sub_q31 (q31_t *pSrcA, q31_t *pSrcB, q31_t *pDst, uint32_t blockSize)
Q31 vector subtraction.

void arm_sub_q7 (q7_t *pSrcA, q7_t *pSrcB, q7_t *pDst, uint32_t blockSize)
Q7 vector subtraction.

## Description

Element-by-element subtraction of two vectors.

```    pDst[n] = pSrcA[n] - pSrcB[n],   0 <= n < blockSize.
```

There are separate functions for floating-point, Q7, Q15, and Q31 data types.

## Function Documentation

 void arm_sub_f32 ( float32_t * `pSrcA, ` float32_t * `pSrcB, ` float32_t * `pDst, ` uint32_t `blockSize ` )
Parameters
 [in] `*pSrcA` points to the first input vector [in] `*pSrcB` points to the second input vector [out] `*pDst` points to the output vector [in] `blockSize` number of samples in each vector
Returns
none.

References blockSize.

Referenced by main().

 void arm_sub_q15 ( q15_t * `pSrcA, ` q15_t * `pSrcB, ` q15_t * `pDst, ` uint32_t `blockSize ` )
Parameters
 [in] `*pSrcA` points to the first input vector [in] `*pSrcB` points to the second input vector [out] `*pDst` points to the output vector [in] `blockSize` number of samples in each vector
Returns
none.

Scaling and Overflow Behavior:

The function uses saturating arithmetic. Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.

References __QSUB16(), __SIMD32, and blockSize.

 void arm_sub_q31 ( q31_t * `pSrcA, ` q31_t * `pSrcB, ` q31_t * `pDst, ` uint32_t `blockSize ` )
Parameters
 [in] `*pSrcA` points to the first input vector [in] `*pSrcB` points to the second input vector [out] `*pDst` points to the output vector [in] `blockSize` number of samples in each vector
Returns
none.

Scaling and Overflow Behavior:

The function uses saturating arithmetic. Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] will be saturated.

References __QSUB(), blockSize, and clip_q63_to_q31().

 void arm_sub_q7 ( q7_t * `pSrcA, ` q7_t * `pSrcB, ` q7_t * `pDst, ` uint32_t `blockSize ` )
Parameters
 [in] `*pSrcA` points to the first input vector [in] `*pSrcB` points to the second input vector [out] `*pDst` points to the output vector [in] `blockSize` number of samples in each vector
Returns
none.

Scaling and Overflow Behavior:

The function uses saturating arithmetic. Results outside of the allowable Q7 range [0x80 0x7F] will be saturated.

References __QSUB8(), __SIMD32, and blockSize.