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Diffstat (limited to 'DSP_Lib/Source/FastMathFunctions/arm_sqrt_q31.c')
| -rw-r--r-- | DSP_Lib/Source/FastMathFunctions/arm_sqrt_q31.c | 153 |
1 files changed, 0 insertions, 153 deletions
diff --git a/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q31.c b/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q31.c deleted file mode 100644 index a9a0bf4..0000000 --- a/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q31.c +++ /dev/null @@ -1,153 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 19. October 2015 -* $Revision: V.1.4.5 a -* -* Project: CMSIS DSP Library -* Title: arm_sqrt_q31.c -* -* Description: Q31 square root function. -* -* 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" -#include "arm_common_tables.h" - -/** - * @ingroup groupFastMath - */ - -/** - * @addtogroup SQRT - * @{ - */ - -/** - * @brief Q31 square root function. - * @param[in] in input value. The range of the input value is [0 +1) or 0x00000000 to 0x7FFFFFFF. - * @param[out] *pOut square root of input value. - * @return The function returns ARM_MATH_SUCCESS if the input value is positive - * and ARM_MATH_ARGUMENT_ERROR if the input is negative. For - * negative inputs, the function returns *pOut = 0. - */ - -arm_status arm_sqrt_q31( - q31_t in, - q31_t * pOut) -{ - q31_t number, temp1, bits_val1, var1, signBits1, half; - float32_t temp_float1; - union - { - q31_t fracval; - float32_t floatval; - } tempconv; - - number = in; - - /* If the input is a positive number then compute the signBits. */ - if(number > 0) - { - signBits1 = __CLZ(number) - 1; - - /* Shift by the number of signBits1 */ - if((signBits1 % 2) == 0) - { - number = number << signBits1; - } - else - { - number = number << (signBits1 - 1); - } - - /* Calculate half value of the number */ - half = number >> 1; - /* Store the number for later use */ - temp1 = number; - - /*Convert to float */ - temp_float1 = number * 4.6566128731e-010f; - /*Store as integer */ - tempconv.floatval = temp_float1; - bits_val1 = tempconv.fracval; - /* Subtract the shifted value from the magic number to give intial guess */ - bits_val1 = 0x5f3759df - (bits_val1 >> 1); /* gives initial guess */ - /* Store as float */ - tempconv.fracval = bits_val1; - temp_float1 = tempconv.floatval; - /* Convert to integer format */ - var1 = (q31_t) (temp_float1 * 1073741824); - - /* 1st iteration */ - var1 = ((q31_t) ((q63_t) var1 * (0x30000000 - - ((q31_t) - ((((q31_t) - (((q63_t) var1 * var1) >> 31)) * - (q63_t) half) >> 31))) >> 31)) << 2; - /* 2nd iteration */ - var1 = ((q31_t) ((q63_t) var1 * (0x30000000 - - ((q31_t) - ((((q31_t) - (((q63_t) var1 * var1) >> 31)) * - (q63_t) half) >> 31))) >> 31)) << 2; - /* 3rd iteration */ - var1 = ((q31_t) ((q63_t) var1 * (0x30000000 - - ((q31_t) - ((((q31_t) - (((q63_t) var1 * var1) >> 31)) * - (q63_t) half) >> 31))) >> 31)) << 2; - - /* Multiply the inverse square root with the original value */ - var1 = ((q31_t) (((q63_t) temp1 * var1) >> 31)) << 1; - - /* Shift the output down accordingly */ - if((signBits1 % 2) == 0) - { - var1 = var1 >> (signBits1 / 2); - } - else - { - var1 = var1 >> ((signBits1 - 1) / 2); - } - *pOut = var1; - - return (ARM_MATH_SUCCESS); - } - /* If the number is a negative number then store zero as its square root value */ - else - { - *pOut = 0; - return (ARM_MATH_ARGUMENT_ERROR); - } -} - -/** - * @} end of SQRT group - */ |