mbed-os 6.10 versione
Diff: cmsis_dsp/SupportFunctions/arm_float_to_q31.c
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/SupportFunctions/arm_float_to_q31.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,203 @@ +/* ---------------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_float_to_q31.c +* +* Description: Converts the elements of the floating-point vector to 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 groupSupport + */ + +/** + * @defgroup float_to_x Convert 32-bit floating point value + */ + +/** + * @addtogroup float_to_x + * @{ + */ + +/** + * @brief Converts the elements of the floating-point vector to Q31 vector. + * @param[in] *pSrc points to the floating-point input vector + * @param[out] *pDst points to the Q31 output vector + * @param[in] blockSize length of the input vector + * @return none. + * + *\par Description: + * \par + * The equation used for the conversion process is: + * + * <pre> + * pDst[n] = (q31_t)(pSrc[n] * 2147483648); 0 <= n < blockSize. + * </pre> + * <b>Scaling and Overflow Behavior:</b> + * \par + * The function uses saturating arithmetic. + * Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated. + * + * \note In order to apply rounding, the library should be rebuilt with the ROUNDING macro + * defined in the preprocessor section of project options. + */ + + +void arm_float_to_q31( + float32_t * pSrc, + q31_t * pDst, + uint32_t blockSize) +{ + float32_t *pIn = pSrc; /* Src pointer */ + uint32_t blkCnt; /* loop counter */ + +#ifdef ARM_MATH_ROUNDING + + float32_t in; + +#endif /* #ifdef ARM_MATH_ROUNDING */ + +#ifndef ARM_MATH_CM0 + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + /*loop Unrolling */ + blkCnt = blockSize >> 2u; + + /* First part of the processing with loop unrolling. Compute 4 outputs at a time. + ** a second loop below computes the remaining 1 to 3 samples. */ + while(blkCnt > 0u) + { + +#ifdef ARM_MATH_ROUNDING + + /* C = A * 32768 */ + /* convert from float to Q31 and then store the results in the destination buffer */ + in = *pIn++; + in = (in * 2147483648.0f); + in += in > 0 ? 0.5 : -0.5; + *pDst++ = clip_q63_to_q31((q63_t) (in)); + + in = *pIn++; + in = (in * 2147483648.0f); + in += in > 0 ? 0.5 : -0.5; + *pDst++ = clip_q63_to_q31((q63_t) (in)); + + in = *pIn++; + in = (in * 2147483648.0f); + in += in > 0 ? 0.5 : -0.5; + *pDst++ = clip_q63_to_q31((q63_t) (in)); + + in = *pIn++; + in = (in * 2147483648.0f); + in += in > 0 ? 0.5 : -0.5; + *pDst++ = clip_q63_to_q31((q63_t) (in)); + +#else + + /* C = A * 2147483648 */ + /* convert from float to Q31 and then store the results in the destination buffer */ + *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f)); + *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f)); + *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f)); + *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f)); + +#endif /* #ifdef ARM_MATH_ROUNDING */ + + /* Decrement the loop counter */ + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, compute any remaining output samples here. + ** No loop unrolling is used. */ + blkCnt = blockSize % 0x4u; + + while(blkCnt > 0u) + { + +#ifdef ARM_MATH_ROUNDING + + /* C = A * 2147483648 */ + /* convert from float to Q31 and then store the results in the destination buffer */ + in = *pIn++; + in = (in * 2147483648.0f); + in += in > 0 ? 0.5 : -0.5; + *pDst++ = clip_q63_to_q31((q63_t) (in)); + +#else + + /* C = A * 2147483648 */ + /* convert from float to Q31 and then store the results in the destination buffer */ + *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f)); + +#endif /* #ifdef ARM_MATH_ROUNDING */ + + /* Decrement the loop counter */ + blkCnt--; + } + + +#else + + /* Run the below code for Cortex-M0 */ + + /* Loop over blockSize number of values */ + blkCnt = blockSize; + + while(blkCnt > 0u) + { + +#ifdef ARM_MATH_ROUNDING + + /* C = A * 2147483648 */ + /* convert from float to Q31 and then store the results in the destination buffer */ + in = *pIn++; + in = (in * 2147483648.0f); + in += in > 0 ? 0.5f : -0.5f; + *pDst++ = clip_q63_to_q31((q63_t) (in)); + +#else + + /* C = A * 2147483648 */ + /* convert from float to Q31 and then store the results in the destination buffer */ + *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f)); + +#endif /* #ifdef ARM_MATH_ROUNDING */ + + /* Decrement the loop counter */ + blkCnt--; + } + +#endif /* #ifndef ARM_MATH_CM0 */ + +} + +/** + * @} end of float_to_x group + */