1 /* ----------------------------------------------------------------------------
2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
4 * $Date: 17. January 2013
7 * Project: CMSIS DSP Library
8 * Title: arm_q7_to_q15.c
10 * Description: Converts the elements of the Q7 vector to Q15 vector.
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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15 * modification, are permitted provided that the following conditions
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27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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39 * ---------------------------------------------------------------------------- */
44 * @ingroup groupSupport
56 * @brief Converts the elements of the Q7 vector to Q15 vector.
57 * @param[in] *pSrc points to the Q7 input vector
58 * @param[out] *pDst points to the Q15 output vector
59 * @param[in] blockSize length of the input vector
64 * The equation used for the conversion process is:
67 * pDst[n] = (q15_t) pSrc[n] << 8; 0 <= n < blockSize.
78 q7_t *pIn = pSrc; /* Src pointer */
79 uint32_t blkCnt; /* loop counter */
81 #ifndef ARM_MATH_CM0_FAMILY
86 /* Run the below code for Cortex-M4 and Cortex-M3 */
89 blkCnt = blockSize >> 2u;
91 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
92 ** a second loop below computes the remaining 1 to 3 samples. */
95 /* C = (q15_t) A << 8 */
96 /* convert from q7 to q15 and then store the results in the destination buffer */
97 in = *__SIMD32(pIn)++;
99 /* rotatate in by 8 and extend two q7_t values to q15_t values */
100 in1 = __SXTB16(__ROR(in, 8));
102 /* extend remainig two q7_t values to q15_t values */
108 in1 = in1 & 0xFF00FF00;
109 in2 = in2 & 0xFF00FF00;
111 #ifndef ARM_MATH_BIG_ENDIAN
113 out2 = __PKHTB(in1, in2, 16);
114 out1 = __PKHBT(in2, in1, 16);
118 out1 = __PKHTB(in1, in2, 16);
119 out2 = __PKHBT(in2, in1, 16);
123 *__SIMD32(pDst)++ = out1;
124 *__SIMD32(pDst)++ = out2;
126 /* Decrement the loop counter */
130 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
131 ** No loop unrolling is used. */
132 blkCnt = blockSize % 0x4u;
136 /* Run the below code for Cortex-M0 */
138 /* Loop over blockSize number of values */
141 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
145 /* C = (q15_t) A << 8 */
146 /* convert from q7 to q15 and then store the results in the destination buffer */
147 *pDst++ = (q15_t) * pIn++ << 8;
149 /* Decrement the loop counter */
156 * @} end of q7_to_x group