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author | px4dev <px4@purgatory.org> | 2013-01-06 12:52:05 -0800 |
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committer | px4dev <px4@purgatory.org> | 2013-01-06 12:52:05 -0800 |
commit | 4447282260be0780eb6e36f5e953bf56888a5688 (patch) | |
tree | 3ba1e976d998d433397343b79a0612af52075aef /apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q31.c | |
parent | 659543f852d18197f68fafee5db5671567b74f4b (diff) | |
download | px4-firmware-4447282260be0780eb6e36f5e953bf56888a5688.tar.gz px4-firmware-4447282260be0780eb6e36f5e953bf56888a5688.tar.bz2 px4-firmware-4447282260be0780eb6e36f5e953bf56888a5688.zip |
Integrate the interesting parts of the CMSIS 3.01 (r3p1) DSP library
Diffstat (limited to 'apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q31.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q31.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q31.c b/apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q31.c new file mode 100644 index 000000000..d9e3e7aa3 --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q31.c @@ -0,0 +1,125 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_abs_q31.c
+*
+* Description: Q31 vector absolute value.
+*
+* 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 1.0.10 2011/7/15
+* Big Endian support added and Merged M0 and M3/M4 Source code.
+*
+* Version 1.0.3 2010/11/29
+* Re-organized the CMSIS folders and updated documentation.
+*
+* Version 1.0.2 2010/11/11
+* Documentation updated.
+*
+* Version 1.0.1 2010/10/05
+* Production release and review comments incorporated.
+*
+* Version 1.0.0 2010/09/20
+* Production release and review comments incorporated.
+*
+* Version 0.0.7 2010/06/10
+* Misra-C changes done
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**
+ * @ingroup groupMath
+ */
+
+/**
+ * @addtogroup BasicAbs
+ * @{
+ */
+
+
+/**
+ * @brief Q31 vector absolute value.
+ * @param[in] *pSrc points to the input buffer
+ * @param[out] *pDst points to the output buffer
+ * @param[in] blockSize number of samples in each vector
+ * @return none.
+ *
+ * <b>Scaling and Overflow Behavior:</b>
+ * \par
+ * The function uses saturating arithmetic.
+ * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
+ */
+
+void arm_abs_q31(
+ q31_t * pSrc,
+ q31_t * pDst,
+ uint32_t blockSize)
+{
+ uint32_t blkCnt; /* loop counter */
+ q31_t in; /* Input value */
+
+#ifndef ARM_MATH_CM0
+
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+ q31_t in1, in2, in3, in4;
+
+ /*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| */
+ /* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */
+ in1 = *pSrc++;
+ in2 = *pSrc++;
+ in3 = *pSrc++;
+ in4 = *pSrc++;
+
+ *pDst++ = (in1 > 0) ? in1 : __QSUB(0, in1);
+ *pDst++ = (in2 > 0) ? in2 : __QSUB(0, in2);
+ *pDst++ = (in3 > 0) ? in3 : __QSUB(0, in3);
+ *pDst++ = (in4 > 0) ? in4 : __QSUB(0, in4);
+
+ /* Decrement the 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 */
+
+ while(blkCnt > 0u)
+ {
+ /* C = |A| */
+ /* Calculate absolute value of the input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */
+ in = *pSrc++;
+ *pDst++ = (in > 0) ? in : ((in == 0x80000000) ? 0x7fffffff : -in);
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+}
+
+/**
+ * @} end of BasicAbs group
+ */
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