// Sse version of RevbinPermuteInv function.
static void RevbinPermuteInvSse(const OMX_F32 *in,
OMX_F32 *out,
const OMX_F32 *twiddle,
OMX_INT n) {
OMX_INT i;
OMX_INT j;
OMX_INT n_by_2 = n >> 1;
OMX_INT n_by_4 = n >> 2;
const OMX_F32 *tw;
const OMX_F32 *pi;
const OMX_F32 *pj;
VC v_i;
VC v_j;
VC v_big_a;
VC v_big_b;
VC v_temp;
VC v_tw;
for (i = 0, j = n_by_2 - 3; i < n_by_4; i += 4, j -= 4) {
pi = in + (i << 1);
pj = in + (j << 1);
VC_LOAD_INTERLEAVE(&v_i, pi);
v_j.real = _mm_set_ps(pj[0], pj[2], pj[4], pj[6]);
v_j.imag = _mm_set_ps(pj[1], pj[3], pj[5], pj[7]);
// A[k] = (X[k] + X'[N/2 - k])
VC_ADD_SUB(&v_big_a, &v_i, &v_j);
// temp = (X[k] - X'[N/2 - k])
VC_SUB_ADD(&v_temp, &v_i, &v_j);
// W[k]
tw = twiddle + i;
VC_LOAD_SPLIT(&v_tw, tw, n);
// B[k] = (X[k] - X'[N/2 - k]) * W[k]
VC_CONJ_MUL(&v_big_b, &v_temp, &v_tw);
// Convert split format to interleaved format.
// Z[k] = (A[k] + j * B[k]) (k = 0, ..., N/2 - 1)
// The scaling of 1/2 will be merged into to the scaling in
// the last step before the output in omxSP_FFTInv_CCSToR_F32_Sfs.
VC_ADD_X_STORE_SPLIT((out + i), &v_big_a, &v_big_b, n_by_2);
VC_SUB_X_INVERSE_STOREU_SPLIT((out + j), &v_big_a, &v_big_b, n_by_2);
}
// The n_by_2 complex point
out[n_by_4] = 2.0f * in[n_by_2];
out[n_by_4 + n_by_2] = -2.0f * in[n_by_2 + 1];
// The first complex point
out[0] = in[0] + in[n];
out[n_by_2] = in[0] - in[n];
}
// Sse version of RevbinPermuteFwd function.
static void RevbinPermuteFwdSse(
const OMX_F32 *in,
OMX_F32 *out,
const OMX_F32 *twiddle,
OMX_INT n) {
OMX_INT i;
OMX_INT j;
OMX_INT n_by_2 = n >> 1;
OMX_INT n_by_4 = n >> 2;
VC v_i;
VC v_j;
VC v_big_a;
VC v_big_b;
VC v_temp;
VC v_x0;
VC v_x1;
VC v_tw;
__m128 factor = _mm_set1_ps(0.5f);
for (i = 0, j = n_by_2 - 3; i < n_by_4; i += 4, j -= 4) {
VC_LOAD_SPLIT(&v_i, (in + i), n_by_2);
VC_LOADU_SPLIT(&v_j, (in + j), n_by_2);
VC_REVERSE(&v_j);
// A[k] = (Z[k] + Z'[N/2 - k])
VC_ADD_SUB(&v_big_a, &v_j, &v_i);
// B[k] = -j * (Z[k] - Z'[N/2 - k])
VC_SUB_ADD(&v_big_b, &v_j, &v_i);
// W[k]
VC_LOAD_SPLIT(&v_tw, (twiddle + i), n);
// temp = B[k] * W[k]
VC_CONJ_MUL(&v_temp, &v_big_b, &v_tw);
VC_SUB_X(&v_x0, &v_big_a, &v_temp);
VC_ADD_X(&v_x1, &v_big_a, &v_temp);
VC_MUL_F(&v_x0, &v_x0, factor);
VC_MUL_F(&v_x1, &v_x1, factor);
// X[k] = A[k] + B[k] * W[k] (k = 0, ..., N/2 - 1)
VC_STORE_INTERLEAVE((out + (i << 1)), &v_x0);
// X[k] = X'[N - k] (k = N/2 + 1, ..., N - 1)
VC_REVERSE(&v_x1);
VC_STOREU_INTERLEAVE((out + (j << 1)), &v_x1);
}
out[n_by_2] = in[n_by_4];
out[n_by_2 + 1] = -in[n_by_4 + n_by_2];
out[0] = in[0] + in[n_by_2];
out[1] = 0;
out[n] = in[0] - in[n_by_2];
out[n + 1] = 0;
}