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Using multiply-accumulate in NEON

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This commit is contained in:
Carles Fernandez 2016-03-12 19:30:00 +01:00
parent c236c3ab67
commit f7c1c9ce43
3 changed files with 193 additions and 7 deletions
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14
src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/kernels/volk_gnsssdr/volk_gnsssdr_16ic_x2_dot_prod_16ic.h
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@ -307,7 +307,7 @@ static inline void volk_gnsssdr_16ic_x2_dot_prod_16ic_neon_fma(lv_16sc_t* out, c
// for 2-lane vectors, 1st lane holds the real part,
// 2nd lane holds the imaginary part
int16x4x2_t a_val, b_val, accumulator;
int16x4x2_t tmp_imag;
int16x4x2_t tmp;
__VOLK_ATTR_ALIGNED(16) lv_16sc_t accum_result[4];
accumulator.val[0] = vdup_n_s16(0);
accumulator.val[1] = vdup_n_s16(0);
@ -319,15 +319,15 @@ static inline void volk_gnsssdr_16ic_x2_dot_prod_16ic_neon_fma(lv_16sc_t* out, c
__builtin_prefetch(a_ptr + 8);
__builtin_prefetch(b_ptr + 8);
tmp_imag.val[0] = vmul_s16(a_val.val[0], b_val.val[0]);
tmp_imag.val[1] = vmul_s16(a_val.val[1], b_val.val[0]);
tmp.val[0] = vmul_s16(a_val.val[0], b_val.val[0]);
tmp.val[1] = vmul_s16(a_val.val[1], b_val.val[0]);
// use multiply accumulate/subtract to get result
tmp_imag.val[0] = vmls_s16(tmp_imag.val[0], a_val.val[1], b_val.val[1]);
tmp_imag.val[1] = vmla_s16(tmp_imag.val[1], a_val.val[0], b_val.val[1]);
tmp.val[0] = vmls_s16(tmp.val[0], a_val.val[1], b_val.val[1]);
tmp.val[1] = vmla_s16(tmp.val[1], a_val.val[0], b_val.val[1]);
accumulator.val[0] = vadd_s16(accumulator.val[0], tmp_imag.val[0]);
accumulator.val[1] = vadd_s16(accumulator.val[1], tmp_imag.val[1]);
accumulator.val[0] = vadd_s16(accumulator.val[0], tmp.val[0]);
accumulator.val[1] = vadd_s16(accumulator.val[1], tmp.val[1]);
a_ptr += 4;
b_ptr += 4;

155
src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/kernels/volk_gnsssdr/volk_gnsssdr_16ic_x2_rotator_dot_prod_16ic_xn.h
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@ -574,4 +574,159 @@ static inline void volk_gnsssdr_16ic_x2_rotator_dot_prod_16ic_xn_neon(lv_16sc_t*
#endif /* LV_HAVE_NEON */
#ifdef LV_HAVE_NEON
#include <arm_neon.h>
static inline void volk_gnsssdr_16ic_x2_rotator_dot_prod_16ic_xn_neon_fma(lv_16sc_t* result, const lv_16sc_t* in_common, const lv_32fc_t phase_inc, lv_32fc_t* phase, const lv_16sc_t** in_a, int num_a_vectors, unsigned int num_points)
{
const unsigned int neon_iters = num_points / 4;
const lv_16sc_t** _in_a = in_a;
const lv_16sc_t* _in_common = in_common;
lv_16sc_t* _out = result;
lv_16sc_t tmp16_, tmp;
lv_32fc_t tmp32_;
if (neon_iters > 0)
{
lv_16sc_t dotProduct = lv_cmake(0,0);
lv_32fc_t ___phase4 = phase_inc * phase_inc * phase_inc * phase_inc;
__VOLK_ATTR_ALIGNED(16) float32_t __phase4_real[4] = { lv_creal(___phase4), lv_creal(___phase4), lv_creal(___phase4), lv_creal(___phase4) };
__VOLK_ATTR_ALIGNED(16) float32_t __phase4_imag[4] = { lv_cimag(___phase4), lv_cimag(___phase4), lv_cimag(___phase4), lv_cimag(___phase4) };
float32x4_t _phase4_real = vld1q_f32(__phase4_real);
float32x4_t _phase4_imag = vld1q_f32(__phase4_imag);
lv_32fc_t phase2 = (lv_32fc_t)(*phase) * phase_inc;
lv_32fc_t phase3 = phase2 * phase_inc;
lv_32fc_t phase4 = phase3 * phase_inc;
__VOLK_ATTR_ALIGNED(16) float32_t __phase_real[4] = { lv_creal((*phase)), lv_creal(phase2), lv_creal(phase3), lv_creal(phase4) };
__VOLK_ATTR_ALIGNED(16) float32_t __phase_imag[4] = { lv_cimag((*phase)), lv_cimag(phase2), lv_cimag(phase3), lv_cimag(phase4) };
float32x4_t _phase_real = vld1q_f32(__phase_real);
float32x4_t _phase_imag = vld1q_f32(__phase_imag);
int16x4x2_t a_val, b_val;
__VOLK_ATTR_ALIGNED(16) lv_16sc_t dotProductVector[4];
float32x4_t half = vdupq_n_f32(0.5f);
int16x4x2_t tmp16;
int32x4x2_t tmp32i;
float32x4x2_t tmp32f, tmp32_real, tmp32_imag;
float32x4_t sign, PlusHalf, Round;
int16x4x2_t* accumulator;
accumulator = (int16x4x2_t*)calloc(num_a_vectors, sizeof(int16x4x2_t));
for(int n_vec = 0; n_vec < num_a_vectors; n_vec++)
{
accumulator[n_vec].val[0] = vdup_n_s16(0);
accumulator[n_vec].val[1] = vdup_n_s16(0);
}
for(unsigned int number = 0; number < neon_iters; number++)
{
/* load 4 complex numbers (int 16 bits each component) */
tmp16 = vld2_s16((int16_t*)_in_common);
__builtin_prefetch(_in_common + 8);
_in_common += 4;
/* promote them to int 32 bits */
tmp32i.val[0] = vmovl_s16(tmp16.val[0]);
tmp32i.val[1] = vmovl_s16(tmp16.val[1]);
/* promote them to float 32 bits */
tmp32f.val[0] = vcvtq_f32_s32(tmp32i.val[0]);
tmp32f.val[1] = vcvtq_f32_s32(tmp32i.val[1]);
/* complex multiplication of four complex samples (float 32 bits each component) */
tmp32_real.val[0] = vmulq_f32(tmp32f.val[0], _phase_real);
tmp32_real.val[1] = vmulq_f32(tmp32f.val[1], _phase_imag);
tmp32_imag.val[0] = vmulq_f32(tmp32f.val[0], _phase_imag);
tmp32_imag.val[1] = vmulq_f32(tmp32f.val[1], _phase_real);
tmp32f.val[0] = vsubq_f32(tmp32_real.val[0], tmp32_real.val[1]);
tmp32f.val[1] = vaddq_f32(tmp32_imag.val[0], tmp32_imag.val[1]);
/* downcast results to int32 */
/* in __aarch64__ we can do that with vcvtaq_s32_f32(ret1); vcvtaq_s32_f32(ret2); */
sign = vcvtq_f32_u32((vshrq_n_u32(vreinterpretq_u32_f32(tmp32f.val[0]), 31)));
PlusHalf = vaddq_f32(tmp32f.val[0], half);
Round = vsubq_f32(PlusHalf, sign);
tmp32i.val[0] = vcvtq_s32_f32(Round);
sign = vcvtq_f32_u32((vshrq_n_u32(vreinterpretq_u32_f32(tmp32f.val[1]), 31)));
PlusHalf = vaddq_f32(tmp32f.val[1], half);
Round = vsubq_f32(PlusHalf, sign);
tmp32i.val[1] = vcvtq_s32_f32(Round);
/* downcast results to int16 */
tmp16.val[0] = vqmovn_s32(tmp32i.val[0]);
tmp16.val[1] = vqmovn_s32(tmp32i.val[1]);
/* compute next four phases */
tmp32_real.val[0] = vmulq_f32(_phase_real, _phase4_real);
tmp32_real.val[1] = vmulq_f32(_phase_imag, _phase4_imag);
tmp32_imag.val[0] = vmulq_f32(_phase_real, _phase4_imag);
tmp32_imag.val[1] = vmulq_f32(_phase_imag, _phase4_real);
_phase_real = vsubq_f32(tmp32_real.val[0], tmp32_real.val[1]);
_phase_imag = vaddq_f32(tmp32_imag.val[0], tmp32_imag.val[1]);
vst1q_f32((float32_t*)__phase_real, _phase_real);
vst1q_f32((float32_t*)__phase_imag, _phase_imag);
for (int n_vec = 0; n_vec < num_a_vectors; n_vec++)
{
a_val = vld2_s16((int16_t*)&(_in_a[n_vec][number*4]));
b_val.val[0] = vmul_s16(a_val.val[0], tmp16.val[0]);
b_val.val[1] = vmul_s16(a_val.val[1], tmp16.val[0]);
// use multiply accumulate/subtract to get result
b_val.val[0] = vmls_s16(b_val.val[0], a_val.val[1], tmp16.val[1]);
b_val.val[1] = vmla_s16(b_val.val[1], a_val.val[0], tmp16.val[1]);
accumulator[n_vec].val[0] = vqadd_s16(accumulator[n_vec].val[0], b_val.val[0]);
accumulator[n_vec].val[1] = vqadd_s16(accumulator[n_vec].val[1], b_val.val[1]);
}
}
for (int n_vec = 0; n_vec < num_a_vectors; n_vec++)
{
vst2_s16((int16_t*)dotProductVector, accumulator[n_vec]); // Store the results back into the dot product vector
dotProduct = lv_cmake(0,0);
for (int i = 0; i < 4; ++i)
{
dotProduct = lv_cmake(sat_adds16i(lv_creal(dotProduct), lv_creal(dotProductVector[i])),
sat_adds16i(lv_cimag(dotProduct), lv_cimag(dotProductVector[i])));
}
_out[n_vec] = dotProduct;
}
free(accumulator);
vst1q_f32((float32_t*)__phase_real, _phase_real);
vst1q_f32((float32_t*)__phase_imag, _phase_imag);
(*phase) = lv_cmake((float32_t)__phase_real[0], (float32_t)__phase_imag[0]);
}
for (unsigned int n = neon_iters * 4; n < num_points; n++)
{
tmp16_ = in_common[n]; //printf("neon phase %i: %f,%f\n", n,lv_creal(*phase),lv_cimag(*phase));
tmp32_ = lv_cmake((float32_t)lv_creal(tmp16_), (float32_t)lv_cimag(tmp16_)) * (*phase);
tmp16_ = lv_cmake((int16_t)rintf(lv_creal(tmp32_)), (int16_t)rintf(lv_cimag(tmp32_)));
(*phase) *= phase_inc;
for (int n_vec = 0; n_vec < num_a_vectors; n_vec++)
{
tmp = tmp16_ * in_a[n_vec][n];
_out[n_vec] = lv_cmake(sat_adds16i(lv_creal(_out[n_vec]), lv_creal(tmp)), sat_adds16i(lv_cimag(_out[n_vec]), lv_cimag(tmp)));
}
}
}
#endif /* LV_HAVE_NEON */
#endif /*INCLUDED_volk_gnsssdr_16ic_x2_dot_prod_16ic_xn_H*/

31
src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/kernels/volk_gnsssdr/volk_gnsssdr_16ic_x2_rotator_dotprodxnpuppet_16ic.h
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@ -161,6 +161,37 @@ static inline void volk_gnsssdr_16ic_x2_rotator_dotprodxnpuppet_16ic_neon(lv_16s
#endif // NEON
#ifdef LV_HAVE_NEON
static inline void volk_gnsssdr_16ic_x2_rotator_dotprodxnpuppet_16ic_neon_fma(lv_16sc_t* result, const lv_16sc_t* local_code, const lv_16sc_t* in, unsigned int num_points)
{
// phases must be normalized. Phase rotator expects a complex exponential input!
float rem_carrier_phase_in_rad = 0.345;
float phase_step_rad = 0.1;
lv_32fc_t phase[1];
phase[0] = lv_cmake(cos(rem_carrier_phase_in_rad), sin(rem_carrier_phase_in_rad));
lv_32fc_t phase_inc[1];
phase_inc[0] = lv_cmake(cos(phase_step_rad), sin(phase_step_rad));
int num_a_vectors = 3;
lv_16sc_t** in_a = (lv_16sc_t**)volk_gnsssdr_malloc(sizeof(lv_16sc_t*) * num_a_vectors, volk_gnsssdr_get_alignment());
for(unsigned int n = 0; n < num_a_vectors; n++)
{
in_a[n] = (lv_16sc_t*)volk_gnsssdr_malloc(sizeof(lv_16sc_t) * num_points, volk_gnsssdr_get_alignment());
memcpy((lv_16sc_t*)in_a[n], (lv_16sc_t*)in, sizeof(lv_16sc_t) * num_points);
}
volk_gnsssdr_16ic_x2_rotator_dot_prod_16ic_xn_neon_fma(result, local_code, phase_inc[0], phase, (const lv_16sc_t**) in_a, num_a_vectors, num_points);
for(unsigned int n = 0; n < num_a_vectors; n++)
{
volk_gnsssdr_free(in_a[n]);
}
volk_gnsssdr_free(in_a);
}
#endif // NEON
#endif // INCLUDED_volk_gnsssdr_16ic_x2_rotator_dotprodxnpuppet_16ic_H