CMSIS DSP library
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Diff: cmsis_dsp/StatisticsFunctions/arm_min_q31.c
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/StatisticsFunctions/arm_min_q31.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,168 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_min_q31.c +* +* Description: Minimum value of a Q31 vector. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Version 1.1.0 2012/02/15 +* Updated with more optimizations, bug fixes and minor API changes. +* +* 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. +* ---------------------------------------------------------------------------- */ + +#include "arm_math.h" + +/** + * @ingroup groupStats + */ + + +/** + * @addtogroup Min + * @{ + */ + + +/** + * @brief Minimum value of a Q31 vector. + * @param[in] *pSrc points to the input vector + * @param[in] blockSize length of the input vector + * @param[out] *pResult minimum value returned here + * @param[out] *pIndex index of minimum value returned here + * @return none. + * + */ + +void arm_min_q31( + q31_t * pSrc, + uint32_t blockSize, + q31_t * pResult, + uint32_t * pIndex) +{ +#ifndef ARM_MATH_CM0 + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + q31_t minVal1, minVal2, out; /* Temporary variables to store the output value. */ + uint32_t blkCnt, outIndex, count; /* loop counter */ + + /* Initialise the count value. */ + count = 0u; + /* Initialise the index value to zero. */ + outIndex = 0u; + /* Load first input value that act as reference value for comparision */ + out = *pSrc++; + + + /* Loop unrolling */ + blkCnt = (blockSize - 1u) >> 2u; + + while(blkCnt > 0) + { + /* Initialize minVal to the next consecutive values one by one */ + minVal1 = *pSrc++; + minVal2 = *pSrc++; + + /* compare for the minimum value */ + if(out > minVal1) + { + /* Update the minimum value and its index */ + out = minVal1; + outIndex = count + 1u; + } + + minVal1 = *pSrc++; + + /* compare for the minimum value */ + if(out > minVal2) + { + /* Update the minimum value and its index */ + out = minVal2; + outIndex = count + 2u; + } + + minVal2 = *pSrc++; + + /* compare for the minimum value */ + if(out > minVal1) + { + /* Update the minimum value and its index */ + out = minVal1; + outIndex = count + 3u; + } + + /* compare for the minimum value */ + if(out > minVal2) + { + /* Update the minimum value and its index */ + out = minVal2; + outIndex = count + 4u; + } + + count += 4u; + + blkCnt--; + } + + /* if (blockSize - 1u ) is not multiple of 4 */ + blkCnt = (blockSize - 1u) % 4u; + +#else + + /* Run the below code for Cortex-M0 */ + q31_t minVal1, out; /* Temporary variables to store the output value. */ + uint32_t blkCnt, outIndex; /* loop counter */ + + blkCnt = (blockSize - 1u); + + /* Initialise the index value to zero. */ + outIndex = 0u; + /* Load first input value that act as reference value for comparision */ + out = *pSrc++; + +#endif // #ifndef ARM_MATH_CM0 + + while(blkCnt > 0) + { + /* Initialize minVal to the next consecutive values one by one */ + minVal1 = *pSrc++; + + /* compare for the minimum value */ + if(out > minVal1) + { + /* Update the minimum value and it's index */ + out = minVal1; + outIndex = blockSize - blkCnt; + } + + blkCnt--; + + } + + /* Store the minimum value and its index into destination pointers */ + *pResult = out; + *pIndex = outIndex; +} + +/** + * @} end of Min group + */