/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_min_q31.c * Description: Minimum value of a Q31 vector * * $Date: 23 April 2021 * $Revision: V1.9.0 * * Target Processor: Cortex-M and Cortex-A cores * -------------------------------------------------------------------- */ /* * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the License); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an AS IS BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "dsp/statistics_functions.h" /** @ingroup groupStats */ /** @addtogroup Min @{ */ /** @brief Minimum value of a Q31 vector. @param[in] pSrc points to the input vector @param[in] blockSize number of samples in input vector @param[out] pResult minimum value returned here @param[out] pIndex index of minimum value returned here @return none */ #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE) #include "arm_helium_utils.h" void arm_min_q31( const q31_t * pSrc, uint32_t blockSize, q31_t * pResult, uint32_t * pIndex) { int32_t blkCnt; /* loop counters */ q31x4_t extremValVec = vdupq_n_s32(Q31_MAX); q31_t minValue = Q31_MAX; uint32x4_t indexVec; uint32x4_t extremIdxVec; mve_pred16_t p0; uint32_t extremIdxArr[4]; indexVec = vidupq_u32(0U, 1); blkCnt = blockSize; do { mve_pred16_t p = vctp32q(blkCnt); q31x4_t extremIdxVal = vld1q_z_s32(pSrc, p); /* * Get current min per lane and current index per lane * when a min is selected */ p0 = vcmpleq_m(extremIdxVal, extremValVec, p); extremValVec = vorrq_m(extremValVec, extremIdxVal, extremIdxVal, p0); /* store per-lane extrema indexes */ vst1q_p_u32(extremIdxArr, indexVec, p0); indexVec += 4; pSrc += 4; blkCnt -= 4; } while (blkCnt > 0); /* Get min value across the vector */ minValue = vminvq(minValue, extremValVec); /* set index for lower values to min possible index */ p0 = vcmpleq(extremValVec, minValue); extremIdxVec = vld1q_u32(extremIdxArr); indexVec = vpselq(extremIdxVec, vdupq_n_u32(blockSize - 1), p0); *pIndex = vminvq(blockSize - 1, indexVec); *pResult = minValue; } #else void arm_min_q31( const q31_t * pSrc, uint32_t blockSize, q31_t * pResult, uint32_t * pIndex) { q31_t minVal, out; /* Temporary variables to store the output value. */ uint32_t blkCnt, outIndex; /* Loop counter */ #if defined (ARM_MATH_LOOPUNROLL) uint32_t index; /* index of maximum value */ #endif /* Initialise index value to zero. */ outIndex = 0U; /* Load first input value that act as reference value for comparision */ out = *pSrc++; #if defined (ARM_MATH_LOOPUNROLL) /* Initialise index of maximum value. */ index = 0U; /* Loop unrolling: Compute 4 outputs at a time */ blkCnt = (blockSize - 1U) >> 2U; while (blkCnt > 0U) { /* Initialize minVal to next consecutive values one by one */ minVal = *pSrc++; /* compare for the minimum value */ if (out > minVal) { /* Update the minimum value and it's index */ out = minVal; outIndex = index + 1U; } minVal = *pSrc++; if (out > minVal) { out = minVal; outIndex = index + 2U; } minVal = *pSrc++; if (out > minVal) { out = minVal; outIndex = index + 3U; } minVal = *pSrc++; if (out > minVal) { out = minVal; outIndex = index + 4U; } index += 4U; /* Decrement loop counter */ blkCnt--; } /* Loop unrolling: Compute remaining outputs */ blkCnt = (blockSize - 1U) % 4U; #else /* Initialize blkCnt with number of samples */ blkCnt = (blockSize - 1U); #endif /* #if defined (ARM_MATH_LOOPUNROLL) */ while (blkCnt > 0U) { /* Initialize minVal to the next consecutive values one by one */ minVal = *pSrc++; /* compare for the minimum value */ if (out > minVal) { /* Update the minimum value and it's index */ out = minVal; outIndex = blockSize - blkCnt; } /* Decrement loop counter */ blkCnt--; } /* Store the minimum value and it's index into destination pointers */ *pResult = out; *pIndex = outIndex; } #endif /* defined(ARM_MATH_MVEI) */ /** @} end of Min group */