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Diffstat (limited to 'src/modules/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q31.c')
| -rw-r--r-- | src/modules/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q31.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/src/modules/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q31.c b/src/modules/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q31.c new file mode 100644 index 000000000..561225a89 --- /dev/null +++ b/src/modules/mathlib/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q31.c @@ -0,0 +1,195 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_shift_q31.c
+*
+* Description: Shifts the elements of a Q31 vector by a specified number of bits.
+*
+* 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
+ */
+/**
+ * @defgroup shift Vector Shift
+ *
+ * Shifts the elements of a fixed-point vector by a specified number of bits.
+ * There are separate functions for Q7, Q15, and Q31 data types.
+ * The underlying algorithm used is:
+ *
+ * <pre>
+ * pDst[n] = pSrc[n] << shift, 0 <= n < blockSize.
+ * </pre>
+ *
+ * If <code>shift</code> is positive then the elements of the vector are shifted to the left.
+ * If <code>shift</code> is negative then the elements of the vector are shifted to the right.
+ */
+
+/**
+ * @addtogroup shift
+ * @{
+ */
+
+/**
+ * @brief Shifts the elements of a Q31 vector a specified number of bits.
+ * @param[in] *pSrc points to the input vector
+ * @param[in] shiftBits number of bits to shift. A positive value shifts left; a negative value shifts right.
+ * @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 function uses saturating arithmetic.
+ * Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] will be saturated.
+ */
+
+void arm_shift_q31(
+ q31_t * pSrc,
+ int8_t shiftBits,
+ q31_t * pDst,
+ uint32_t blockSize)
+{
+ uint32_t blkCnt; /* loop counter */
+ uint8_t sign = (shiftBits & 0x80); /* Sign of shiftBits */
+
+#ifndef ARM_MATH_CM0
+
+ q31_t in1, in2, in3, in4; /* Temporary input variables */
+ q31_t out1, out2, out3, out4; /* Temporary output variables */
+
+ /*loop Unrolling */
+ blkCnt = blockSize >> 2u;
+
+
+ if(sign == 0u)
+ {
+ /* 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 << shiftBits */
+ /* Shift the input and then store the results in the destination buffer. */
+ in1 = *pSrc;
+ in2 = *(pSrc + 1);
+ out1 = in1 << shiftBits;
+ in3 = *(pSrc + 2);
+ out2 = in2 << shiftBits;
+ in4 = *(pSrc + 3);
+ if(in1 != (out1 >> shiftBits))
+ out1 = 0x7FFFFFFF ^ (in1 >> 31);
+
+ if(in2 != (out2 >> shiftBits))
+ out2 = 0x7FFFFFFF ^ (in2 >> 31);
+
+ *pDst = out1;
+ out3 = in3 << shiftBits;
+ *(pDst + 1) = out2;
+ out4 = in4 << shiftBits;
+
+ if(in3 != (out3 >> shiftBits))
+ out3 = 0x7FFFFFFF ^ (in3 >> 31);
+
+ if(in4 != (out4 >> shiftBits))
+ out4 = 0x7FFFFFFF ^ (in4 >> 31);
+
+ *(pDst + 2) = out3;
+ *(pDst + 3) = out4;
+
+ /* Update destination pointer to process next sampels */
+ pSrc += 4u;
+ pDst += 4u;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+ }
+ else
+ {
+
+ /* 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 >> shiftBits */
+ /* Shift the input and then store the results in the destination buffer. */
+ in1 = *pSrc;
+ in2 = *(pSrc + 1);
+ in3 = *(pSrc + 2);
+ in4 = *(pSrc + 3);
+
+ *pDst = (in1 >> -shiftBits);
+ *(pDst + 1) = (in2 >> -shiftBits);
+ *(pDst + 2) = (in3 >> -shiftBits);
+ *(pDst + 3) = (in4 >> -shiftBits);
+
+
+ pSrc += 4u;
+ pDst += 4u;
+
+ 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 (>> or <<) shiftBits */
+ /* Shift the input and then store the result in the destination buffer. */
+ *pDst++ = (sign == 0u) ? clip_q63_to_q31((q63_t) * pSrc++ << shiftBits) :
+ (*pSrc++ >> -shiftBits);
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+
+}
+
+/**
+ * @} end of shift group
+ */
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