| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010 ARM Limited. All rights reserved. |
| * |
| * $Date: 15. July 2011 |
| * $Revision: V1.0.10 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_mult_q7.c |
| * |
| * Description: Q7 vector multiplication. |
| * |
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
| * |
| * Version 1.0.10 2011/7/15 |
| * Big Endian support added and Merged M0 and M3/M4 Source code. |
| * |
| * Version 1.0.3 2010/11/29 |
| * Re-organized the CMSIS folders and updated documentation. |
| * |
| * Version 1.0.2 2010/11/11 |
| * Documentation updated. |
| * |
| * Version 1.0.1 2010/10/05 |
| * Production release and review comments incorporated. |
| * |
| * Version 1.0.0 2010/09/20 |
| * Production release and review comments incorporated. |
| * |
| * Version 0.0.7 2010/06/10 |
| * Misra-C changes done |
| * |
| * Version 0.0.5 2010/04/26 |
| * incorporated review comments and updated with latest CMSIS layer |
| * |
| * Version 0.0.3 2010/03/10 DP |
| * Initial version |
| * -------------------------------------------------------------------- */ |
| |
| #include "arm_math.h" |
| |
| /** |
| * @ingroup groupMath |
| */ |
| |
| /** |
| * @addtogroup BasicMult |
| * @{ |
| */ |
| |
| /** |
| * @brief Q7 vector multiplication |
| * @param[in] *pSrcA points to the first input vector |
| * @param[in] *pSrcB points to the second input vector |
| * @param[out] *pDst points to the output vector |
| * @param[in] blockSize number of samples in each vector |
| * @return none. |
| * |
| * <b>Scaling and Overflow Behavior:</b> |
| * \par |
| * The function uses saturating arithmetic. |
| * Results outside of the allowable Q7 range [0x80 0x7F] will be saturated. |
| */ |
| |
| void arm_mult_q7( |
| q7_t * pSrcA, |
| q7_t * pSrcB, |
| q7_t * pDst, |
| uint32_t blockSize) |
| { |
| uint32_t blkCnt; /* loop counters */ |
| |
| #ifndef ARM_MATH_CM0 |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| q7_t out1, out2, out3, out4; /* Temporary variables to store the product */ |
| |
| /* loop Unrolling */ |
| blkCnt = blockSize >> 2u; |
| |
| /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
| ** a second loop below computes the remaining 1 to 3 samples. */ |
| while(blkCnt > 0u) |
| { |
| /* C = A * B */ |
| /* Multiply the inputs and store the results in temporary variables */ |
| out1 = (q7_t) (((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7); |
| out2 = (q7_t) (((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7); |
| out3 = (q7_t) (((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7); |
| out4 = (q7_t) (((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7); |
| |
| /* Store the results of 4 inputs in the destination buffer in single cycle by packing */ |
| *__SIMD32(pDst)++ = __PACKq7(out1, out2, out3, out4); |
| |
| /* Decrement the blockSize loop counter */ |
| blkCnt--; |
| } |
| |
| /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
| ** No loop unrolling is used. */ |
| blkCnt = blockSize % 0x4u; |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| /* Initialize blkCnt with number of samples */ |
| blkCnt = blockSize; |
| |
| #endif /* #ifndef ARM_MATH_CM0 */ |
| |
| |
| while(blkCnt > 0u) |
| { |
| /* C = A * B */ |
| /* Multiply the inputs and store the result in the destination buffer */ |
| *pDst++ = (q7_t) (((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7); |
| |
| /* Decrement the blockSize loop counter */ |
| blkCnt--; |
| } |
| } |
| |
| /** |
| * @} end of BasicMult group |
| */ |