/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_f64_to_q15.c * Description: Converts the elements of the 64 bit floating-point vector to Q15 vector * * $Date: 18 August 2022 * $Revision: V1.0.0 * * Target Processor: Cortex-M and Cortex-A cores * -------------------------------------------------------------------- */ /* * Copyright (C) 2010-2022 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/support_functions.h" /** @ingroup groupSupport */ /** @addtogroup f64_to_x @{ */ /** @brief Converts the elements of the 64 bit floating-point vector to Q15 vector. @param[in] pSrc points to the 64 bit floating-point input vector @param[out] pDst points to the Q15 output vector @param[in] blockSize number of samples in each vector @par Details The equation used for the conversion process is:
      pDst[n] = (q15_t)(pSrc[n] * 32768);   0 <= n < blockSize.
  
@par Scaling and Overflow Behavior The function uses saturating arithmetic. Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated. @note In order to apply rounding, the library should be rebuilt with the ROUNDING macro defined in the preprocessor section of project options. */ ARM_DSP_ATTRIBUTE void arm_f64_to_q15( const float64_t * pSrc, q15_t * pDst, uint32_t blockSize) { uint32_t blkCnt; /* Loop counter */ const float64_t *pIn = pSrc; /* Source pointer */ #ifdef ARM_MATH_ROUNDING float64_t in; #endif /* #ifdef ARM_MATH_ROUNDING */ #if defined (ARM_MATH_LOOPUNROLL) /* Loop unrolling: Compute 4 outputs at a time */ blkCnt = blockSize >> 2U; while (blkCnt > 0U) { /* C = A * 32768 */ /* convert from float to Q15 and store result in destination buffer */ #ifdef ARM_MATH_ROUNDING in = (*pIn++ * 32768.0); in += in > 0.0 ? 0.5 : -0.5; *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16)); in = (*pIn++ * 32768.0); in += in > 0.0 ? 0.5 : -0.5; *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16)); in = (*pIn++ * 32768.0); in += in > 0.0 ? 0.5 : -0.5; *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16)); in = (*pIn++ * 32768.0); in += in > 0.0 ? 0.5 : -0.5; *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16)); #else *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0), 16); *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0), 16); *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0), 16); *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0), 16); #endif /* #ifdef ARM_MATH_ROUNDING */ /* 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 = A * 32768 */ /* convert from float to Q15 and store result in destination buffer */ #ifdef ARM_MATH_ROUNDING in = (*pIn++ * 32768.0); in += in > 0.0 ? 0.5 : -0.5; *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16)); #else /* C = A * 32768 */ /* Convert from float to q15 and then store the results in the destination buffer */ *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0), 16); #endif /* #ifdef ARM_MATH_ROUNDING */ /* Decrement loop counter */ blkCnt--; } } /** @} end of f64_to_x group */