diff options
Diffstat (limited to 'src/modules/mathlib/CMSIS/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q15.c')
| -rw-r--r-- | src/modules/mathlib/CMSIS/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q15.c | 131 |
1 files changed, 0 insertions, 131 deletions
diff --git a/src/modules/mathlib/CMSIS/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q15.c b/src/modules/mathlib/CMSIS/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q15.c deleted file mode 100644 index 0a6d6a53a..000000000 --- a/src/modules/mathlib/CMSIS/DSP_Lib/Source/FastMathFunctions/arm_sqrt_q15.c +++ /dev/null @@ -1,131 +0,0 @@ -/* ----------------------------------------------------------------------
-* Copyright (C) 2011 ARM Limited. All rights reserved.
-*
-* $Date: 15. February 2012
-* $Revision: V1.1.0
-*
-* Project: CMSIS DSP Library
-* Title: arm_sqrt_q15.c
-*
-* Description: Q15 square root function.
-*
-* 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 1.0.0 2011/03/08
-* Alpha release.
-*
-* Version 1.0.1 2011/09/30
-* Beta release.
-*
-* -------------------------------------------------------------------- */
-#include "arm_math.h"
-#include "arm_common_tables.h"
-
-
-/**
- * @ingroup groupFastMath
- */
-
-/**
- * @addtogroup SQRT
- * @{
- */
-
- /**
- * @brief Q15 square root function.
- * @param[in] in input value. The range of the input value is [0 +1) or 0x0000 to 0x7FFF.
- * @param[out] *pOut square root of input value.
- * @return The function returns ARM_MATH_SUCCESS if input value is positive value or ARM_MATH_ARGUMENT_ERROR if
- * <code>in</code> is negative value and returns zero output for negative values.
- */
-
-arm_status arm_sqrt_q15(
- q15_t in,
- q15_t * pOut)
-{
- q15_t number, temp1, var1, signBits1, half;
- q31_t bits_val1;
- float32_t temp_float1;
-
- number = in;
-
- /* If the input is a positive number then compute the signBits. */
- if(number > 0)
- {
- signBits1 = __CLZ(number) - 17;
-
- /* 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 * 3.051757812500000e-005f;
- /*Store as integer */
- bits_val1 = *(int *) &temp_float1;
- /* Subtract the shifted value from the magic number to give intial guess */
- bits_val1 = 0x5f3759df - (bits_val1 >> 1); // gives initial guess
- /* Store as float */
- temp_float1 = *(float *) &bits_val1;
- /* Convert to integer format */
- var1 = (q31_t) (temp_float1 * 16384);
-
- /* 1st iteration */
- var1 = ((q15_t) ((q31_t) var1 * (0x3000 -
- ((q15_t)
- ((((q15_t)
- (((q31_t) var1 * var1) >> 15)) *
- (q31_t) half) >> 15))) >> 15)) << 2;
- /* 2nd iteration */
- var1 = ((q15_t) ((q31_t) var1 * (0x3000 -
- ((q15_t)
- ((((q15_t)
- (((q31_t) var1 * var1) >> 15)) *
- (q31_t) half) >> 15))) >> 15)) << 2;
- /* 3rd iteration */
- var1 = ((q15_t) ((q31_t) var1 * (0x3000 -
- ((q15_t)
- ((((q15_t)
- (((q31_t) var1 * var1) >> 15)) *
- (q31_t) half) >> 15))) >> 15)) << 2;
-
- /* Multiply the inverse square root with the original value */
- var1 = ((q15_t) (((q31_t) temp1 * var1) >> 15)) << 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
- */
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