mirrors/gnss-sdr
1
0
Fork 0
mirror of https://github.com/gnss-sdr/gnss-sdr synced 2024-12-14 12:10:34 +00:00
Code Issues Releases Wiki Activity

add neon implementation

Browse Source
This commit is contained in:
Carles Fernandez 2016-01-24 12:01:40 +01:00
parent cd2f0b86f6
commit 812a4df93f
2 changed files with 96 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

84
src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/kernels/volk_gnsssdr/volk_gnsssdr_16ic_resampler_16ic.h
View File

@ -233,4 +233,88 @@ static inline void volk_gnsssdr_16ic_resampler_16ic_u_sse2(lv_16sc_t* result, co
#endif /* LV_HAVE_SSE2 */
#ifdef LV_HAVE_NEON
#include <arm_neon.h>
static inline void volk_gnsssdr_16ic_resampler_16ic_neon(lv_16sc_t* result, const lv_16sc_t* local_code, float rem_code_phase_chips, float code_phase_step_chips, int code_length_chips, unsigned int num_output_samples)//, int* scratch_buffer, float* scratch_buffer_float)
{
unsigned int number;
const unsigned int quarterPoints = num_output_samples / 4;
float32x4_t half = vdupq_n_f32(0.5f);
lv_16sc_t* _result = result;
__attribute__((aligned(16))) int local_code_chip_index[4];
float32x4_t _rem_code_phase, _code_phase_step_chips;
int32x4_t _code_length_chips, _code_length_chips_minus1;
float32x4_t _code_phase_out, _code_phase_out_with_offset;
rem_code_phase_chips = rem_code_phase_chips - 0.5f;
float32x4_t sign, PlusHalf, Round;
_rem_code_phase = vld1q_dup_f32(&rem_code_phase_chips); //load float to all four float values in m128 register
_code_phase_step_chips = vld1q_dup_f32(&code_phase_step_chips); //load float to all four float values in m128 register
__attribute__((aligned(16))) int four_times_code_length_chips_minus1[4];
four_times_code_length_chips_minus1[0] = code_length_chips - 1;
four_times_code_length_chips_minus1[1] = code_length_chips - 1;
four_times_code_length_chips_minus1[2] = code_length_chips - 1;
four_times_code_length_chips_minus1[3] = code_length_chips - 1;
__attribute__((aligned(16))) int four_times_code_length_chips[4];
four_times_code_length_chips[0] = code_length_chips;
four_times_code_length_chips[1] = code_length_chips;
four_times_code_length_chips[2] = code_length_chips;
four_times_code_length_chips[3] = code_length_chips;
_code_length_chips = vld1q_s32((int32_t*)&four_times_code_length_chips); //load float to all four float values in m128 register
_code_length_chips_minus1 = vld1q_s32((int32_t*)&four_times_code_length_chips_minus1); //load float to all four float values in m128 register
int32x4_t _code_phase_out_int, _code_phase_out_int_neg, _code_phase_out_int_over;
uint32x4_t negative_indexes, overflow_indexes;
int32x4_t zero = vmovq_n_s32(0);
__attribute__((aligned(16))) float init_idx_float[4] = { 0.0f, 1.0f, 2.0f, 3.0f };
float32x4_t _4output_index = vld1q_f32(init_idx_float);
__attribute__((aligned(16))) float init_4constant_float[4] = { 4.0f, 4.0f, 4.0f, 4.0f };
float32x4_t _4constant_float = vld1q_f32(init_4constant_float);
for(number = 0; number < quarterPoints; number++)
{
_code_phase_out = vmulq_f32(_code_phase_step_chips, _4output_index); //compute the code phase point with the phase step
_code_phase_out_with_offset = vaddq_f32(_code_phase_out, _rem_code_phase); //add the phase offset
//_code_phase_out_int = _mm_cvtps_epi32(_code_phase_out_with_offset); //convert to integer int32x4_t = f(float32x4_t)
sign = vcvtq_f32_u32((vshrq_n_u32(vreinterpretq_u32_f32(_code_phase_out_with_offset), 31)));
PlusHalf = vaddq_f32(_code_phase_out_with_offset, half);
Round = vsubq_f32(PlusHalf, sign);
_code_phase_out_int = vcvtq_s32_f32(Round);
negative_indexes = vcltq_s32(_code_phase_out_int, zero); //test for negative values
_code_phase_out_int_neg = vaddq_s32(_code_phase_out_int, _code_length_chips); //the negative values branch
_code_phase_out_int_neg = veorq_s32(_code_phase_out_int, vandq_s32( (int32x4_t)negative_indexes, veorq_s32( _code_phase_out_int_neg, _code_phase_out_int )));
overflow_indexes = vcgtq_s32(_code_phase_out_int_neg, _code_length_chips_minus1); //test for overflow values
_code_phase_out_int_over = vsubq_s32(_code_phase_out_int_neg, _code_length_chips); //the negative values branch
_code_phase_out_int_over = veorq_s32(_code_phase_out_int_neg, vandq_s32( (int32x4_t)overflow_indexes, veorq_s32( _code_phase_out_int_over, _code_phase_out_int_neg )));
vst1q_s32((int32_t*)local_code_chip_index, _code_phase_out_int_over); // Store the results back
//todo: optimize the local code lookup table with intrinsics, if possible
*_result++ = local_code[local_code_chip_index[0]];
*_result++ = local_code[local_code_chip_index[1]];
*_result++ = local_code[local_code_chip_index[2]];
*_result++ = local_code[local_code_chip_index[3]];
_4output_index = vaddq_f32(_4output_index, _4constant_float);
}
for(number = quarterPoints * 4; number < num_output_samples; number++)
{
local_code_chip_index[0] = (int)(code_phase_step_chips * (float)number + rem_code_phase_chips + 0.5f);
if (local_code_chip_index[0] < 0.0) local_code_chip_index[0] += code_length_chips - 1;
if (local_code_chip_index[0] > (code_length_chips - 1)) local_code_chip_index[0] -= code_length_chips;
*_result++ = local_code[local_code_chip_index[0]];
}
}
#endif /* LV_HAVE_NEON */
#endif /*INCLUDED_volk_gnsssdr_16ic_resampler_16ic_H*/

12
src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/kernels/volk_gnsssdr/volk_gnsssdr_16ic_resamplerpuppet_16ic.h
View File

@ -72,4 +72,16 @@ static inline void volk_gnsssdr_16ic_resamplerpuppet_16ic_u_sse2(lv_16sc_t* resu
#endif /* LV_HAVE_SSE2 */
#ifdef LV_HAVE_NEON
static inline void volk_gnsssdr_16ic_resamplerpuppet_16ic_neon(lv_16sc_t* result, const lv_16sc_t* local_code, unsigned int num_points)
{
float rem_code_phase_chips = -0.123;
float code_phase_step_chips = 0.1;
int code_length_chips = 1023;
volk_gnsssdr_16ic_resampler_16ic_neon(result, local_code, rem_code_phase_chips, code_phase_step_chips, code_length_chips, num_points );
}
#endif /* LV_HAVE_NEON */
#endif // INCLUDED_volk_gnsssdr_16ic_resamplerpuppet_16ic_H