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| author | jaseg <git@jaseg.net> | 2020-10-14 12:47:28 +0200 |
|---|---|---|
| committer | jaseg <git@jaseg.net> | 2020-10-14 12:47:28 +0200 |
| commit | 6ab94e0b318884bbcb95e2ea3835f951502e1d99 (patch) | |
| tree | 4cc5794b89f89c55ff8370ae252518ab96b5fed3 /fw/midi-dials/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sqrt_q31.c | |
| parent | 1e6e8a2062923b434b2f4f5f2a9f8c0098135b01 (diff) | |
| download | minikbd-6ab94e0b318884bbcb95e2ea3835f951502e1d99.tar.gz minikbd-6ab94e0b318884bbcb95e2ea3835f951502e1d99.tar.bz2 minikbd-6ab94e0b318884bbcb95e2ea3835f951502e1d99.zip | |
Move firmware into subdirectory
Diffstat (limited to 'fw/midi-dials/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sqrt_q31.c')
| -rw-r--r-- | fw/midi-dials/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sqrt_q31.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/fw/midi-dials/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sqrt_q31.c b/fw/midi-dials/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sqrt_q31.c new file mode 100644 index 0000000..de8c35f --- /dev/null +++ b/fw/midi-dials/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sqrt_q31.c @@ -0,0 +1,142 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_sqrt_q31.c
+ * Description: Q31 square root function
+ *
+ * $Date: 27. January 2017
+ * $Revision: V.1.5.1
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#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
+ */
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