diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q31_to_q7.c')
-rw-r--r-- | Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q31_to_q7.c | 94 |
1 files changed, 40 insertions, 54 deletions
diff --git a/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q31_to_q7.c b/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q31_to_q7.c index f092bed14..c7d1b4cec 100644 --- a/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q31_to_q7.c +++ b/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q31_to_q7.c @@ -3,13 +3,13 @@ * Title: arm_q31_to_q7.c * Description: Converts the elements of the Q31 vector to Q7 vector * - * $Date: 27. January 2017 - * $Revision: V.1.5.1 + * $Date: 18. March 2019 + * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* - * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * @@ -29,96 +29,82 @@ #include "arm_math.h" /** - * @ingroup groupSupport + @ingroup groupSupport */ /** - * @addtogroup q31_to_x - * @{ + @addtogroup q31_to_x + @{ */ /** - * @brief Converts the elements of the Q31 vector to Q7 vector. - * @param[in] *pSrc points to the Q31 input vector - * @param[out] *pDst points to the Q7 output vector - * @param[in] blockSize length of the input vector - * @return none. - * - * \par Description: - * - * The equation used for the conversion process is: - * - * <pre> - * pDst[n] = (q7_t) pSrc[n] >> 24; 0 <= n < blockSize. - * </pre> - * + @brief Converts the elements of the Q31 vector to Q7 vector. + @param[in] pSrc points to the Q31 input vector + @param[out] pDst points to the Q7 output vector + @param[in] blockSize number of samples in each vector + @return none + + @par Details + The equation used for the conversion process is: + <pre> + pDst[n] = (q7_t) pSrc[n] >> 24; 0 <= n < blockSize. + </pre> */ - void arm_q31_to_q7( - q31_t * pSrc, - q7_t * pDst, - uint32_t blockSize) + const q31_t * pSrc, + q7_t * pDst, + uint32_t blockSize) { - q31_t *pIn = pSrc; /* Src pointer */ - uint32_t blkCnt; /* loop counter */ + uint32_t blkCnt; /* Loop counter */ + const q31_t *pIn = pSrc; /* Source pointer */ -#if defined (ARM_MATH_DSP) +#if defined (ARM_MATH_LOOPUNROLL) - /* Run the below code for Cortex-M4 and Cortex-M3 */ - q31_t in1, in2, in3, in4; q7_t out1, out2, out3, out4; - /*loop Unrolling */ + /* Loop unrolling: Compute 4 outputs at a time */ 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 = (q7_t) A >> 24 */ - /* convert from q31 to q7 and then store the results in the destination buffer */ - in1 = *pIn++; - in2 = *pIn++; - in3 = *pIn++; - in4 = *pIn++; + /* C = (q7_t) (A >> 24) */ - out1 = (q7_t) (in1 >> 24); - out2 = (q7_t) (in2 >> 24); - out3 = (q7_t) (in3 >> 24); - out4 = (q7_t) (in4 >> 24); + /* Convert from q31 to q7 and store result in destination buffer */ - *__SIMD32(pDst)++ = __PACKq7(out1, out2, out3, out4); + out1 = (q7_t) (*pIn++ >> 24); + out2 = (q7_t) (*pIn++ >> 24); + out3 = (q7_t) (*pIn++ >> 24); + out4 = (q7_t) (*pIn++ >> 24); + write_q7x4_ia (&pDst, __PACKq7(out1, out2, out3, out4)); - /* Decrement the loop counter */ + /* Decrement loop counter */ blkCnt--; } - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ + /* Loop unrolling: Compute remaining outputs */ blkCnt = blockSize % 0x4U; #else - /* Run the below code for Cortex-M0 */ - - /* Loop over blockSize number of values */ + /* Initialize blkCnt with number of samples */ blkCnt = blockSize; -#endif /* #if defined (ARM_MATH_DSP) */ +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ while (blkCnt > 0U) { - /* C = (q7_t) A >> 24 */ - /* convert from q31 to q7 and then store the results in the destination buffer */ + /* C = (q7_t) (A >> 24) */ + + /* Convert from q31 to q7 and store result in destination buffer */ *pDst++ = (q7_t) (*pIn++ >> 24); - /* Decrement the loop counter */ + /* Decrement loop counter */ blkCnt--; } } /** - * @} end of q31_to_x group + @} end of q31_to_x group */ |