/* ---------------------------------------------------------------------- * Copyright (C) 2010-2013 ARM Limited. All rights reserved. * * $Date: 17. January 2013 * $Revision: V1.4.1 * * Project: CMSIS DSP Library * Title: arm_mat_scale_f32.c * * Description: Multiplies a floating-point matrix by a scalar. * * 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 groupMatrix */ /** * @defgroup MatrixScale Matrix Scale * * Multiplies a matrix by a scalar. This is accomplished by multiplying each element in the * matrix by the scalar. For example: * \image html MatrixScale.gif "Matrix Scaling of a 3 x 3 matrix" * * The function checks to make sure that the input and output matrices are of the same size. * * In the fixed-point Q15 and Q31 functions, scale is represented by * a fractional multiplication scaleFract and an arithmetic shift shift. * The shift allows the gain of the scaling operation to exceed 1.0. * The overall scale factor applied to the fixed-point data is *
        
 *     scale = scaleFract * 2^shift.        
 * 
*/ /** * @addtogroup MatrixScale * @{ */ /** * @brief Floating-point matrix scaling. * @param[in] *pSrc points to input matrix structure * @param[in] scale scale factor to be applied * @param[out] *pDst points to output matrix structure * @return The function returns either ARM_MATH_SIZE_MISMATCH * or ARM_MATH_SUCCESS based on the outcome of size checking. * */ arm_status arm_mat_scale_f32( const arm_matrix_instance_f32 * pSrc, float32_t scale, arm_matrix_instance_f32 * pDst) { float32_t *pIn = pSrc->pData; /* input data matrix pointer */ float32_t *pOut = pDst->pData; /* output data matrix pointer */ uint32_t numSamples; /* total number of elements in the matrix */ uint32_t blkCnt; /* loop counters */ arm_status status; /* status of matrix scaling */ #ifndef ARM_MATH_CM0_FAMILY float32_t in1, in2, in3, in4; /* temporary variables */ float32_t out1, out2, out3, out4; /* temporary variables */ #endif // #ifndef ARM_MATH_CM0_FAMILY #ifdef ARM_MATH_MATRIX_CHECK /* Check for matrix mismatch condition */ if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols)) { /* Set status as ARM_MATH_SIZE_MISMATCH */ status = ARM_MATH_SIZE_MISMATCH; } else #endif /* #ifdef ARM_MATH_MATRIX_CHECK */ { /* Total number of samples in the input matrix */ numSamples = (uint32_t) pSrc->numRows * pSrc->numCols; #ifndef ARM_MATH_CM0_FAMILY /* Run the below code for Cortex-M4 and Cortex-M3 */ /* Loop Unrolling */ blkCnt = numSamples >> 2; /* 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(m,n) = A(m,n) * scale */ /* Scaling and results are stored in the destination buffer. */ in1 = pIn[0]; in2 = pIn[1]; in3 = pIn[2]; in4 = pIn[3]; out1 = in1 * scale; out2 = in2 * scale; out3 = in3 * scale; out4 = in4 * scale; pOut[0] = out1; pOut[1] = out2; pOut[2] = out3; pOut[3] = out4; /* update pointers to process next sampels */ pIn += 4u; pOut += 4u; /* Decrement the numSamples loop counter */ blkCnt--; } /* If the numSamples is not a multiple of 4, compute any remaining output samples here. ** No loop unrolling is used. */ blkCnt = numSamples % 0x4u; #else /* Run the below code for Cortex-M0 */ /* Initialize blkCnt with number of samples */ blkCnt = numSamples; #endif /* #ifndef ARM_MATH_CM0_FAMILY */ while(blkCnt > 0u) { /* C(m,n) = A(m,n) * scale */ /* The results are stored in the destination buffer. */ *pOut++ = (*pIn++) * scale; /* Decrement the loop counter */ blkCnt--; } /* Set status as ARM_MATH_SUCCESS */ status = ARM_MATH_SUCCESS; } /* Return to application */ return (status); } /** * @} end of MatrixScale group */