pigweed / third_party / github / STMicroelectronics / cmsis_core / 7dd288b23bf605a3a2fafa81a29d2c96a2fd83ce / . / DSP_Lib / Source / BasicMathFunctions / arm_mult_f32.c

/* ---------------------------------------------------------------------- | |

* Copyright (C) 2010-2014 ARM Limited. All rights reserved. | |

* | |

* $Date: 19. March 2015 | |

* $Revision: V.1.4.5 | |

* | |

* Project: CMSIS DSP Library | |

* Title: arm_mult_f32.c | |

* | |

* Description: Floating-point vector multiplication. | |

* | |

* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | |

* | |

* Redistribution and use in source and binary forms, with or without | |

* modification, are permitted provided that the following conditions | |

* are met: | |

* - Redistributions of source code must retain the above copyright | |

* notice, this list of conditions and the following disclaimer. | |

* - Redistributions in binary form must reproduce the above copyright | |

* notice, this list of conditions and the following disclaimer in | |

* the documentation and/or other materials provided with the | |

* distribution. | |

* - Neither the name of ARM LIMITED nor the names of its contributors | |

* may be used to endorse or promote products derived from this | |

* software without specific prior written permission. | |

* | |

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |

* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |

* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |

* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | |

* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, | |

* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, | |

* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |

* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |

* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |

* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN | |

* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |

* POSSIBILITY OF SUCH DAMAGE. | |

* -------------------------------------------------------------------- */ | |

#include "arm_math.h" | |

/** | |

* @ingroup groupMath | |

*/ | |

/** | |

* @defgroup BasicMult Vector Multiplication | |

* | |

* Element-by-element multiplication of two vectors. | |

* | |

* <pre> | |

* pDst[n] = pSrcA[n] * pSrcB[n], 0 <= n < blockSize. | |

* </pre> | |

* | |

* There are separate functions for floating-point, Q7, Q15, and Q31 data types. | |

*/ | |

/** | |

* @addtogroup BasicMult | |

* @{ | |

*/ | |

/** | |

* @brief Floating-point vector multiplication. | |

* @param[in] *pSrcA points to the first input vector | |

* @param[in] *pSrcB points to the second input vector | |

* @param[out] *pDst points to the output vector | |

* @param[in] blockSize number of samples in each vector | |

* @return none. | |

*/ | |

void arm_mult_f32( | |

float32_t * pSrcA, | |

float32_t * pSrcB, | |

float32_t * pDst, | |

uint32_t blockSize) | |

{ | |

uint32_t blkCnt; /* loop counters */ | |

#ifndef ARM_MATH_CM0_FAMILY | |

/* Run the below code for Cortex-M4 and Cortex-M3 */ | |

float32_t inA1, inA2, inA3, inA4; /* temporary input variables */ | |

float32_t inB1, inB2, inB3, inB4; /* temporary input variables */ | |

float32_t out1, out2, out3, out4; /* temporary output variables */ | |

/* 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) | |

{ | |

/* C = A * B */ | |

/* Multiply the inputs and store the results in output buffer */ | |

/* read sample from sourceA */ | |

inA1 = *pSrcA; | |

/* read sample from sourceB */ | |

inB1 = *pSrcB; | |

/* read sample from sourceA */ | |

inA2 = *(pSrcA + 1); | |

/* read sample from sourceB */ | |

inB2 = *(pSrcB + 1); | |

/* out = sourceA * sourceB */ | |

out1 = inA1 * inB1; | |

/* read sample from sourceA */ | |

inA3 = *(pSrcA + 2); | |

/* read sample from sourceB */ | |

inB3 = *(pSrcB + 2); | |

/* out = sourceA * sourceB */ | |

out2 = inA2 * inB2; | |

/* read sample from sourceA */ | |

inA4 = *(pSrcA + 3); | |

/* store result to destination buffer */ | |

*pDst = out1; | |

/* read sample from sourceB */ | |

inB4 = *(pSrcB + 3); | |

/* out = sourceA * sourceB */ | |

out3 = inA3 * inB3; | |

/* store result to destination buffer */ | |

*(pDst + 1) = out2; | |

/* out = sourceA * sourceB */ | |

out4 = inA4 * inB4; | |

/* store result to destination buffer */ | |

*(pDst + 2) = out3; | |

/* store result to destination buffer */ | |

*(pDst + 3) = out4; | |

/* update pointers to process next samples */ | |

pSrcA += 4u; | |

pSrcB += 4u; | |

pDst += 4u; | |

/* Decrement the blockSize 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; | |

#else | |

/* Run the below code for Cortex-M0 */ | |

/* Initialize blkCnt with number of samples */ | |

blkCnt = blockSize; | |

#endif /* #ifndef ARM_MATH_CM0_FAMILY */ | |

while(blkCnt > 0u) | |

{ | |

/* C = A * B */ | |

/* Multiply the inputs and store the results in output buffer */ | |

*pDst++ = (*pSrcA++) * (*pSrcB++); | |

/* Decrement the blockSize loop counter */ | |

blkCnt--; | |

} | |

} | |

/** | |

* @} end of BasicMult group | |

*/ |