/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_absmax_q15.c * Description: Maximum value of absolute values of a Q15 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 AbsMax @{ */ /** @brief Maximum value of absolute values of a Q15 vector. @param[in] pSrc points to the input vector @param[in] blockSize number of samples in input vector @param[out] pResult maximum value returned here @param[out] pIndex index of maximum value returned here @return none */ #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE) #include "arm_helium_utils.h" void arm_absmax_q15( const q15_t * pSrc, uint32_t blockSize, q15_t * pResult, uint32_t * pIndex) { int32_t blkCnt; /* loop counters */ q15x8_t extremValVec = vdupq_n_s16(Q15_ABSMIN); q15_t maxValue = Q15_ABSMIN; uint16x8_t indexVec; uint16x8_t extremIdxVec; mve_pred16_t p0; uint16_t extremIdxArr[8]; indexVec = vidupq_u16(0U, 1); blkCnt = blockSize; do { mve_pred16_t p = vctp16q(blkCnt); q15x8_t extremIdxVal = vld1q_z_s16(pSrc, p); extremIdxVal = vabsq(extremIdxVal); /* * Get current max per lane and current index per lane * when a max is selected */ p0 = vcmpgeq_m(extremIdxVal, extremValVec, p); extremValVec = vorrq_m(extremValVec, extremIdxVal, extremIdxVal, p0); /* store per-lane extrema indexes */ vst1q_p_u16(extremIdxArr, indexVec, p0); indexVec += 8; pSrc += 8; blkCnt -= 8; } while (blkCnt > 0); /* Get max value across the vector */ maxValue = vmaxvq(maxValue, extremValVec); /* set index for lower values to max possible index */ p0 = vcmpgeq(extremValVec, maxValue); extremIdxVec = vld1q_u16(extremIdxArr); indexVec = vpselq(extremIdxVec, vdupq_n_u16(blockSize - 1), p0); *pIndex = vminvq(blockSize - 1, indexVec); *pResult = maxValue; } #else #if defined(ARM_MATH_DSP) void arm_absmax_q15( const q15_t * pSrc, uint32_t blockSize, q15_t * pResult, uint32_t * pIndex) { q15_t cur_absmax, out; /* Temporary variables to store the output value. */\ uint32_t blkCnt, outIndex; /* Loop counter */ \ uint32_t index; /* index of maximum value */ \ \ /* Initialize index value to zero. */ \ outIndex = 0U; \ /* Load first input value that act as reference value for comparision */ \ out = *pSrc++; \ out = (out > 0) ? out : (q15_t)__QSUB16(0, out); \ /* Initialize index of extrema value. */ \ index = 0U; \ \ /* Loop unrolling: Compute 4 outputs at a time */ \ blkCnt = (blockSize - 1U) >> 2U; \ \ while (blkCnt > 0U) \ { \ /* Initialize cur_absmax to next consecutive values one by one */ \ cur_absmax = *pSrc++; \ cur_absmax = (cur_absmax > 0) ? cur_absmax : (q15_t)__QSUB16(0, cur_absmax); \ /* compare for the extrema value */ \ if (cur_absmax > out) \ { \ /* Update the extrema value and it's index */ \ out = cur_absmax; \ outIndex = index + 1U; \ } \ \ cur_absmax = *pSrc++; \ cur_absmax = (cur_absmax > 0) ? cur_absmax : (q15_t)__QSUB16(0, cur_absmax); \ if (cur_absmax > out) \ { \ out = cur_absmax; \ outIndex = index + 2U; \ } \ \ cur_absmax = *pSrc++; \ cur_absmax = (cur_absmax > 0) ? cur_absmax : (q15_t)__QSUB16(0, cur_absmax); \ if (cur_absmax > out) \ { \ out = cur_absmax; \ outIndex = index + 3U; \ } \ \ cur_absmax = *pSrc++; \ cur_absmax = (cur_absmax > 0) ? cur_absmax : (q15_t)__QSUB16(0, cur_absmax); \ if (cur_absmax > out) \ { \ out = cur_absmax; \ outIndex = index + 4U; \ } \ \ index += 4U; \ \ /* Decrement loop counter */ \ blkCnt--; \ } \ \ /* Loop unrolling: Compute remaining outputs */ \ blkCnt = (blockSize - 1U) % 4U; \ \ \ while (blkCnt > 0U) \ { \ cur_absmax = *pSrc++; \ cur_absmax = (cur_absmax > 0) ? cur_absmax : (q15_t)__QSUB16(0, cur_absmax); \ if (cur_absmax > out) \ { \ out = cur_absmax; \ outIndex = blockSize - blkCnt; \ } \ \ /* Decrement loop counter */ \ blkCnt--; \ } \ \ /* Store the extrema value and it's index into destination pointers */ \ *pResult = out; \ *pIndex = outIndex; } #else void arm_absmax_q15( const q15_t * pSrc, uint32_t blockSize, q15_t * pResult, uint32_t * pIndex) { q15_t maxVal, out; /* Temporary variables to store the output value. */ uint32_t blkCnt, outIndex; /* Loop counter */ /* Initialise index value to zero. */ outIndex = 0U; /* Load first input value that act as reference value for comparision */ out = (*pSrc > 0) ? *pSrc : ((*pSrc == (q15_t) 0x8000) ? 0x7fff : -*pSrc); pSrc++; /* Initialize blkCnt with number of samples */ blkCnt = (blockSize - 1U); while (blkCnt > 0U) { /* Initialize maxVal to the next consecutive values one by one */ maxVal = (*pSrc > 0) ? *pSrc : ((*pSrc == (q15_t) 0x8000) ? 0x7fff : -*pSrc); pSrc++; /* compare for the maximum value */ if (out < maxVal) { /* Update the maximum value and it's index */ out = maxVal; outIndex = blockSize - blkCnt; } /* Decrement loop counter */ blkCnt--; } /* Store the maximum value and it's index into destination pointers */ *pResult = out; *pIndex = outIndex; } #endif /* defined(ARM_MATH_DSP) */ #endif /* defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE) */ /** @} end of AbsMax group */