/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_q7_to_float.c * Description: Converts the elements of the Q7 vector to floating-point vector * * $Date: 18. March 2019 * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* * Copyright (C) 2010-2019 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 "arm_math.h" /** @ingroup groupSupport */ /** * @defgroup q7_to_x Convert 8-bit Integer value */ /** @addtogroup q7_to_x @{ */ /** @brief Converts the elements of the Q7 vector to floating-point vector. @param[in] pSrc points to the Q7 input vector @param[out] pDst points to the floating-point output vector @param[in] blockSize number of samples in each vector @return none @par Details The equation used for the conversion process is:
      pDst[n] = (float32_t) pSrc[n] / 128;   0 <= n < blockSize.
  
*/ #if defined(ARM_MATH_NEON) void arm_q7_to_float( const q7_t * pSrc, float32_t * pDst, uint32_t blockSize) { const q7_t *pIn = pSrc; /* Src pointer */ uint32_t blkCnt; /* loop counter */ int8x16_t inV; int16x8_t inVLO, inVHI; int32x4_t inVLL, inVLH, inVHL, inVHH; float32x4_t outV; blkCnt = blockSize >> 4U; /* Compute 16 outputs at a time. ** a second loop below computes the remaining 1 to 15 samples. */ while (blkCnt > 0U) { /* C = (float32_t) A / 128 */ /* Convert from q7 to float and then store the results in the destination buffer */ inV = vld1q_s8(pIn); pIn += 16; inVLO = vmovl_s8(vget_low_s8(inV)); inVHI = vmovl_s8(vget_high_s8(inV)); inVLL = vmovl_s16(vget_low_s16(inVLO)); inVLH = vmovl_s16(vget_high_s16(inVLO)); inVHL = vmovl_s16(vget_low_s16(inVHI)); inVHH = vmovl_s16(vget_high_s16(inVHI)); outV = vcvtq_n_f32_s32(inVLL,7); vst1q_f32(pDst, outV); pDst += 4; outV = vcvtq_n_f32_s32(inVLH,7); vst1q_f32(pDst, outV); pDst += 4; outV = vcvtq_n_f32_s32(inVHL,7); vst1q_f32(pDst, outV); pDst += 4; outV = vcvtq_n_f32_s32(inVHH,7); vst1q_f32(pDst, outV); pDst += 4; /* Decrement the loop counter */ blkCnt--; } /* If the blockSize is not a multiple of 16, compute any remaining output samples here. ** No loop unrolling is used. */ blkCnt = blockSize & 0xF; while (blkCnt > 0U) { /* C = (float32_t) A / 128 */ /* Convert from q7 to float and then store the results in the destination buffer */ *pDst++ = ((float32_t) * pIn++ / 128.0f); /* Decrement the loop counter */ blkCnt--; } } #else void arm_q7_to_float( const q7_t * pSrc, float32_t * pDst, uint32_t blockSize) { uint32_t blkCnt; /* Loop counter */ const q7_t *pIn = pSrc; /* Source pointer */ #if defined (ARM_MATH_LOOPUNROLL) /* Loop unrolling: Compute 4 outputs at a time */ blkCnt = blockSize >> 2U; while (blkCnt > 0U) { /* C = (float32_t) A / 128 */ /* Convert from q7 to float and store result in destination buffer */ *pDst++ = ((float32_t) * pIn++ / 128.0f); *pDst++ = ((float32_t) * pIn++ / 128.0f); *pDst++ = ((float32_t) * pIn++ / 128.0f); *pDst++ = ((float32_t) * pIn++ / 128.0f); /* Decrement loop counter */ blkCnt--; } /* Loop unrolling: Compute remaining outputs */ blkCnt = blockSize % 0x4U; #else /* Initialize blkCnt with number of samples */ blkCnt = blockSize; #endif /* #if defined (ARM_MATH_LOOPUNROLL) */ while (blkCnt > 0U) { /* C = (float32_t) A / 128 */ /* Convert from q7 to float and store result in destination buffer */ *pDst++ = ((float32_t) * pIn++ / 128.0f); /* Decrement loop counter */ blkCnt--; } } #endif /* #if defined(ARM_MATH_NEON) */ /** @} end of q7_to_x group */