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adding neon implementation

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This commit is contained in:
Carles Fernandez 2016-01-24 20:10:12 +01:00
parent da67f85f6c
commit 3306c21cf8
1 changed files with 67 additions and 0 deletions
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67
src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/kernels/volk_gnsssdr/volk_gnsssdr_8ic_x2_dot_prod_8ic.h
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@ -437,4 +437,71 @@ static inline void volk_gnsssdr_8ic_x2_dot_prod_8ic_u_orc(lv_8sc_t* result, cons
}
#endif /* LV_HAVE_ORC */
#ifdef LV_HAVE_NEON
#include <arm_neon.h>
/*!
\brief Multiplies the two input complex vectors and accumulates them, storing the result in the third vector
\param cVector The vector where the accumulated result will be stored
\param aVector One of the vectors to be multiplied and accumulated
\param bVector One of the vectors to be multiplied and accumulated
\param num_points The number of complex values in aVector and bVector to be multiplied together, accumulated and stored into cVector
*/
static inline void volk_gnsssdr_8ic_x2_dot_prod_8ic_neon(lv_8sc_t* result, const lv_8sc_t* input, const lv_8sc_t* taps, unsigned int num_points)
{
lv_8sc_t dotProduct;
dotProduct = lv_cmake(0,0);
*result = lv_cmake(0,0);
const lv_8sc_t* a = input;
const lv_8sc_t* b = taps;
// for 2-lane vectors, 1st lane holds the real part,
// 2nd lane holds the imaginary part
int8x8x2_t a_val, b_val, c_val, accumulator, tmp_real, tmp_imag;
lv_8sc_t accum_result[8] = { lv_cmake(0,0) };
accumulator.val[0] = vdup_n_s8(0);
accumulator.val[1] = vdup_n_s8(0);
unsigned int number;
const unsigned int neon_iters = num_points / 8;
for(number = 0; number < neon_iters; ++number)
{
a_val = vld2_s8((const int8_t*)a);
b_val = vld2_s8((const int8_t*)b);
__builtin_prefetch(a + 16);
__builtin_prefetch(b + 16);
// multiply the real*real and imag*imag to get real result
tmp_real.val[0] = vmul_s8(a_val.val[0], b_val.val[0]);
tmp_real.val[1] = vmul_s8(a_val.val[1], b_val.val[1]);
// Multiply cross terms to get the imaginary result
tmp_imag.val[0] = vmul_s8(a_val.val[0], b_val.val[1]);
tmp_imag.val[1] = vmul_s8(a_val.val[1], b_val.val[0]);
c_val.val[0] = vsub_s8(tmp_real.val[0], tmp_real.val[1]);
c_val.val[1] = vadd_s8(tmp_imag.val[0], tmp_imag.val[1]);
accumulator.val[0] = vadd_s8(accumulator.val[0], c_val.val[0]);
accumulator.val[1] = vadd_s8(accumulator.val[1], c_val.val[1]);
a += 8;
b += 8;
}
vst2_s8((int8_t*)accum_result, accumulator);
for(number = 0; number < 8; ++number)
{
*result += accum_result[number];
}
for (number = neon_iters * 8; number < num_points; ++number)
{
dotProduct += (*a++) * (*b++);
}
*result += dotProduct;
}
#endif /* LV_HAVE_NEON */
#endif /*INCLUDED_volk_gnsssdr_8ic_x2_dot_prod_8ic_H*/