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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/SupportFunctions/arm_q31_to_q7.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/SupportFunctions/arm_q31_to_q7.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/SupportFunctions/arm_q31_to_q7.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/SupportFunctions/arm_q31_to_q7.c b/apps/mathlib/CMSIS/DSP_Lib/Source/SupportFunctions/arm_q31_to_q7.c new file mode 100644 index 000000000..afc8fdbed --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/SupportFunctions/arm_q31_to_q7.c @@ -0,0 +1,128 @@ +/* ----------------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_q31_to_q7.c
+*
+* Description: Converts the elements of the Q31 vector to Q7 vector.
+*
+* 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.
+* ---------------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**
+ * @ingroup groupSupport
+ */
+
+/**
+ * @addtogroup q31_to_x
+ * @{
+ */
+
+/**
+ * @brief Converts the elements of the Q31 vector to Q7 vector.
+ * @param[in] *pSrc points to the Q31 input vector
+ * @param[out] *pDst points to the Q7 output vector
+ * @param[in] blockSize length of the input vector
+ * @return none.
+ *
+ * \par Description:
+ *
+ * The equation used for the conversion process is:
+ *
+ * <pre>
+ * pDst[n] = (q7_t) pSrc[n] >> 24; 0 <= n < blockSize.
+ * </pre>
+ *
+ */
+
+
+void arm_q31_to_q7(
+ q31_t * pSrc,
+ q7_t * pDst,
+ uint32_t blockSize)
+{
+ q31_t *pIn = pSrc; /* Src pointer */
+ uint32_t blkCnt; /* loop counter */
+
+#ifndef ARM_MATH_CM0
+
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+ q31_t in1, in2, in3, in4;
+ q7_t out1, out2, out3, out4;
+
+ /*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 = (q7_t) A >> 24 */
+ /* convert from q31 to q7 and then store the results in the destination buffer */
+ in1 = *pIn++;
+ in2 = *pIn++;
+ in3 = *pIn++;
+ in4 = *pIn++;
+
+ out1 = (q7_t) (in1 >> 24);
+ out2 = (q7_t) (in2 >> 24);
+ out3 = (q7_t) (in3 >> 24);
+ out4 = (q7_t) (in4 >> 24);
+
+ *__SIMD32(pDst)++ = __PACKq7(out1, out2, out3, out4);
+
+ /* 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 */
+
+ /* Loop over blockSize number of values */
+ blkCnt = blockSize;
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+ while(blkCnt > 0u)
+ {
+ /* C = (q7_t) A >> 24 */
+ /* convert from q31 to q7 and then store the results in the destination buffer */
+ *pDst++ = (q7_t) (*pIn++ >> 24);
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+}
+
+/**
+ * @} end of q31_to_x group
+ */
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