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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_scale_q15.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_scale_q15.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q15.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q15.c b/apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q15.c new file mode 100644 index 000000000..9e79202fe --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q15.c @@ -0,0 +1,157 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_scale_q15.c
+*
+* Description: Multiplies a Q15 vector by a scalar.
+*
+* 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 scale
+ * @{
+ */
+
+/**
+ * @brief Multiplies a Q15 vector by a scalar.
+ * @param[in] *pSrc points to the input vector
+ * @param[in] scaleFract fractional portion of the scale value
+ * @param[in] shift number of bits to shift the result by
+ * @param[out] *pDst points to the output vector
+ * @param[in] blockSize number of samples in the vector
+ * @return none.
+ *
+ * <b>Scaling and Overflow Behavior:</b>
+ * \par
+ * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.
+ * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.
+ */
+
+
+void arm_scale_q15(
+ q15_t * pSrc,
+ q15_t scaleFract,
+ int8_t shift,
+ q15_t * pDst,
+ uint32_t blockSize)
+{
+ int8_t kShift = 15 - shift; /* shift to apply after scaling */
+ uint32_t blkCnt; /* loop counter */
+
+#ifndef ARM_MATH_CM0
+
+/* Run the below code for Cortex-M4 and Cortex-M3 */
+ q15_t in1, in2, in3, in4;
+ q31_t inA1, inA2; /* Temporary variables */
+ q31_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)
+ {
+ /* Reading 2 inputs from memory */
+ inA1 = *__SIMD32(pSrc)++;
+ inA2 = *__SIMD32(pSrc)++;
+
+ /* C = A * scale */
+ /* Scale the inputs and then store the 2 results in the destination buffer
+ * in single cycle by packing the outputs */
+ out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract);
+ out2 = (q31_t) ((q15_t) inA1 * scaleFract);
+ out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract);
+ out4 = (q31_t) ((q15_t) inA2 * scaleFract);
+
+ /* apply shifting */
+ out1 = out1 >> kShift;
+ out2 = out2 >> kShift;
+ out3 = out3 >> kShift;
+ out4 = out4 >> kShift;
+
+ /* saturate the output */
+ in1 = (q15_t) (__SSAT(out1, 16));
+ in2 = (q15_t) (__SSAT(out2, 16));
+ in3 = (q15_t) (__SSAT(out3, 16));
+ in4 = (q15_t) (__SSAT(out4, 16));
+
+ /* store the result to destination */
+ *__SIMD32(pDst)++ = __PKHBT(in2, in1, 16);
+ *__SIMD32(pDst)++ = __PKHBT(in4, in3, 16);
+
+ /* 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;
+
+ while(blkCnt > 0u)
+ {
+ /* C = A * scale */
+ /* Scale the input and then store the result in the destination buffer. */
+ *pDst++ = (q15_t) (__SSAT(((*pSrc++) * scaleFract) >> kShift, 16));
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+#else
+
+ /* Run the below code for Cortex-M0 */
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = blockSize;
+
+ while(blkCnt > 0u)
+ {
+ /* C = A * scale */
+ /* Scale the input and then store the result in the destination buffer. */
+ *pDst++ = (q15_t) (__SSAT(((q31_t) * pSrc++ * scaleFract) >> kShift, 16));
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+}
+
+/**
+ * @} end of scale group
+ */
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